David Vernet [Wed, 24 Jul 2024 17:14:58 +0000 (12:14 -0500)]
libbpf: Don't take direct pointers into BTF data from st_ops
In struct bpf_struct_ops, we have take a pointer to a BTF type name, and
a struct btf_type. This was presumably done for convenience, but can
actually result in subtle and confusing bugs given that BTF data can be
invalidated before a program is loaded. For example, in sched_ext, we
may sometimes resize a data section after a skeleton has been opened,
but before the struct_ops scheduler map has been loaded. This may cause
the BTF data to be realloc'd, which can then cause a UAF when loading
the program because the struct_ops map has pointers directly into the
BTF data.
We're already storing the BTF type_id in struct bpf_struct_ops. Because
type_id is stable, we can therefore just update the places where we were
looking at those pointers to instead do the lookups we need from the
type_id.
Fixes:
590a00888250 ("bpf: libbpf: Add STRUCT_OPS support")
Signed-off-by: David Vernet <void@manifault.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240724171459.281234-1-void@manifault.com
Andrii Nakryiko [Wed, 24 Jul 2024 23:46:05 +0000 (16:46 -0700)]
Merge branch 'selftests-bpf-improve-libc-portability-musl-support-part-1'
Tony Ambardar says:
====================
selftests/bpf: Improve libc portability / musl support (part 1)
Hello all,
This series includes the bulk of libc-related compile fixes accumulated to
support systems using musl, with smaller numbers to follow. These patches
are simple and straightforward, and the series has been tested with the
kernel-patches/bpf CI and locally using mips64el-gcc/musl-libc and QEMU
with an OpenWrt rootfs.
The patches address a few general categories of libc portability issues:
- missing, redundant or incorrect include headers
- disabled GNU header extensions (i.e. missing #define _GNU_SOURCE)
- issues with types and casting
Feedback and suggestions for improvement are welcome!
Thanks,
Tony
====================
Link: https://lore.kernel.org/r/cover.1721713597.git.tony.ambardar@gmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tony Ambardar [Tue, 23 Jul 2024 05:54:46 +0000 (22:54 -0700)]
selftests/bpf: Fix errors compiling cg_storage_multi.h with musl libc
Remove a redundant include of '<asm/types.h>', whose needed definitions are
already included (via '<linux/types.h>') in cg_storage_multi_egress_only.c,
cg_storage_multi_isolated.c, and cg_storage_multi_shared.c. This avoids
redefinition errors seen compiling for mips64el/musl-libc like:
In file included from progs/cg_storage_multi_egress_only.c:13:
In file included from progs/cg_storage_multi.h:6:
In file included from /usr/mips64el-linux-gnuabi64/include/asm/types.h:23:
/usr/include/asm-generic/int-l64.h:29:25: error: typedef redefinition with different types ('long' vs 'long long')
29 | typedef __signed__ long __s64;
| ^
/usr/include/asm-generic/int-ll64.h:30:44: note: previous definition is here
30 | __extension__ typedef __signed__ long long __s64;
| ^
Fixes:
9e5bd1f7633b ("selftests/bpf: Test CGROUP_STORAGE map can't be used by multiple progs")
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/4f4702e9f6115b7f84fea01b2326ca24c6df7ba8.1721713597.git.tony.ambardar@gmail.com
Tony Ambardar [Tue, 23 Jul 2024 05:54:45 +0000 (22:54 -0700)]
selftests/bpf: Fix errors compiling crypto_sanity.c with musl libc
Remove a redundant include of '<linux/in6.h>', whose needed definitions are
already provided by 'test_progs.h'. This avoids errors seen compiling for
mips64el/musl-libc:
In file included from .../arpa/inet.h:9,
from ./test_progs.h:17,
from prog_tests/crypto_sanity.c:10:
.../netinet/in.h:23:8: error: redefinition of 'struct in6_addr'
23 | struct in6_addr {
| ^~~~~~~~
In file included from crypto_sanity.c:7:
.../linux/in6.h:33:8: note: originally defined here
33 | struct in6_addr {
| ^~~~~~~~
.../netinet/in.h:34:8: error: redefinition of 'struct sockaddr_in6'
34 | struct sockaddr_in6 {
| ^~~~~~~~~~~~
.../linux/in6.h:50:8: note: originally defined here
50 | struct sockaddr_in6 {
| ^~~~~~~~~~~~
.../netinet/in.h:42:8: error: redefinition of 'struct ipv6_mreq'
42 | struct ipv6_mreq {
| ^~~~~~~~~
.../linux/in6.h:60:8: note: originally defined here
60 | struct ipv6_mreq {
| ^~~~~~~~~
Fixes:
91541ab192fc ("selftests: bpf: crypto skcipher algo selftests")
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Link: https://lore.kernel.org/bpf/911293968f424ad7b462d8805aeb3baee8f4985b.1721713597.git.tony.ambardar@gmail.com
Tony Ambardar [Tue, 23 Jul 2024 05:54:44 +0000 (22:54 -0700)]
selftests/bpf: Fix errors compiling decap_sanity.c with musl libc
Remove a redundant include of '<linux/in6.h>', whose needed definitions are
already provided by 'test_progs.h'. This avoids errors seen compiling for
mips64el/musl-libc:
In file included from .../arpa/inet.h:9,
from ./test_progs.h:17,
from prog_tests/decap_sanity.c:9:
.../netinet/in.h:23:8: error: redefinition of 'struct in6_addr'
23 | struct in6_addr {
| ^~~~~~~~
In file included from decap_sanity.c:7:
.../linux/in6.h:33:8: note: originally defined here
33 | struct in6_addr {
| ^~~~~~~~
.../netinet/in.h:34:8: error: redefinition of 'struct sockaddr_in6'
34 | struct sockaddr_in6 {
| ^~~~~~~~~~~~
.../linux/in6.h:50:8: note: originally defined here
50 | struct sockaddr_in6 {
| ^~~~~~~~~~~~
.../netinet/in.h:42:8: error: redefinition of 'struct ipv6_mreq'
42 | struct ipv6_mreq {
| ^~~~~~~~~
.../linux/in6.h:60:8: note: originally defined here
60 | struct ipv6_mreq {
| ^~~~~~~~~
Fixes:
70a00e2f1dba ("selftests/bpf: Test bpf_skb_adjust_room on CHECKSUM_PARTIAL")
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/e986ba2d7edccd254b54f7cd049b98f10bafa8c3.1721713597.git.tony.ambardar@gmail.com
Tony Ambardar [Tue, 23 Jul 2024 05:54:43 +0000 (22:54 -0700)]
selftests/bpf: Fix errors compiling lwt_redirect.c with musl libc
Remove a redundant include of '<linux/icmp.h>' which is already provided in
'lwt_helpers.h'. This avoids errors seen compiling for mips64el/musl-libc:
In file included from .../arpa/inet.h:9,
from lwt_redirect.c:51:
.../netinet/in.h:23:8: error: redefinition of 'struct in6_addr'
23 | struct in6_addr {
| ^~~~~~~~
In file included from .../linux/icmp.h:24,
from lwt_redirect.c:50:
.../linux/in6.h:33:8: note: originally defined here
33 | struct in6_addr {
| ^~~~~~~~
.../netinet/in.h:34:8: error: redefinition of 'struct sockaddr_in6'
34 | struct sockaddr_in6 {
| ^~~~~~~~~~~~
.../linux/in6.h:50:8: note: originally defined here
50 | struct sockaddr_in6 {
| ^~~~~~~~~~~~
.../netinet/in.h:42:8: error: redefinition of 'struct ipv6_mreq'
42 | struct ipv6_mreq {
| ^~~~~~~~~
.../linux/in6.h:60:8: note: originally defined here
60 | struct ipv6_mreq {
| ^~~~~~~~~
Fixes:
43a7c3ef8a15 ("selftests/bpf: Add lwt_xmit tests for BPF_REDIRECT")
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/3869dda876d5206d2f8d4dd67331c739ceb0c7f8.1721713597.git.tony.ambardar@gmail.com
Tony Ambardar [Tue, 23 Jul 2024 05:54:42 +0000 (22:54 -0700)]
selftests/bpf: Fix compiling core_reloc.c with musl-libc
The type 'loff_t' is a GNU extension and not exposed by the musl 'fcntl.h'
header unless _GNU_SOURCE is defined. Add this definition to fix errors
seen compiling for mips64el/musl-libc:
In file included from tools/testing/selftests/bpf/prog_tests/core_reloc.c:4:
./bpf_testmod/bpf_testmod.h:10:9: error: unknown type name 'loff_t'
10 | loff_t off;
| ^~~~~~
./bpf_testmod/bpf_testmod.h:16:9: error: unknown type name 'loff_t'
16 | loff_t off;
| ^~~~~~
Fixes:
6bcd39d366b6 ("selftests/bpf: Add CO-RE relocs selftest relying on kernel module BTF")
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/11c3af75a7eb6bcb7ad9acfae6a6f470c572eb82.1721713597.git.tony.ambardar@gmail.com
Tony Ambardar [Tue, 23 Jul 2024 05:54:41 +0000 (22:54 -0700)]
selftests/bpf: Fix compiling tcp_rtt.c with musl-libc
The GNU version of 'struct tcp_info' in 'netinet/tcp.h' is not exposed by
musl headers unless _GNU_SOURCE is defined.
Add this definition to fix errors seen compiling for mips64el/musl-libc:
tcp_rtt.c: In function 'wait_for_ack':
tcp_rtt.c:24:25: error: storage size of 'info' isn't known
24 | struct tcp_info info;
| ^~~~
tcp_rtt.c:24:25: error: unused variable 'info' [-Werror=unused-variable]
cc1: all warnings being treated as errors
Fixes:
1f4f80fed217 ("selftests/bpf: test_progs: convert test_tcp_rtt")
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/f2329767b15df206f08a5776d35a47c37da855ae.1721713597.git.tony.ambardar@gmail.com
Tony Ambardar [Tue, 23 Jul 2024 05:54:40 +0000 (22:54 -0700)]
selftests/bpf: Fix compiling flow_dissector.c with musl-libc
The GNU version of 'struct tcphdr' has members 'doff', 'source' and 'dest',
which are not exposed by musl libc headers unless _GNU_SOURCE is defined.
Add this definition to fix errors seen compiling for mips64el/musl-libc:
flow_dissector.c:118:30: error: 'struct tcphdr' has no member named 'doff'
118 | .tcp.doff = 5,
| ^~~~
flow_dissector.c:119:30: error: 'struct tcphdr' has no member named 'source'
119 | .tcp.source = 80,
| ^~~~~~
flow_dissector.c:120:30: error: 'struct tcphdr' has no member named 'dest'
120 | .tcp.dest = 8080,
| ^~~~
Fixes:
ae173a915785 ("selftests/bpf: support BPF_FLOW_DISSECTOR_F_PARSE_1ST_FRAG")
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/8f7ab21a73f678f9cebd32b26c444a686e57414d.1721713597.git.tony.ambardar@gmail.com
Tony Ambardar [Tue, 23 Jul 2024 05:54:39 +0000 (22:54 -0700)]
selftests/bpf: Fix compiling kfree_skb.c with musl-libc
The GNU version of 'struct tcphdr' with member 'doff' is not exposed by
musl headers unless _GNU_SOURCE is defined. Add this definition to fix
errors seen compiling for mips64el/musl-libc:
In file included from kfree_skb.c:2:
kfree_skb.c: In function 'on_sample':
kfree_skb.c:45:30: error: 'struct tcphdr' has no member named 'doff'
45 | if (CHECK(pkt_v6->tcp.doff != 5, "check_tcp",
| ^
Fixes:
580d656d80cf ("selftests/bpf: Add kfree_skb raw_tp test")
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/e2d8cedc790959c10d6822a51f01a7a3616bea1b.1721713597.git.tony.ambardar@gmail.com
Tony Ambardar [Tue, 23 Jul 2024 05:54:38 +0000 (22:54 -0700)]
selftests/bpf: Fix compiling parse_tcp_hdr_opt.c with musl-libc
The GNU version of 'struct tcphdr', with members 'doff' and 'urg_ptr', is
not exposed by musl headers unless _GNU_SOURCE is defined.
Add this definition to fix errors seen compiling for mips64el/musl-libc:
parse_tcp_hdr_opt.c:18:21: error: 'struct tcphdr' has no member named 'urg_ptr'
18 | .pk6_v6.tcp.urg_ptr = 123,
| ^~~~~~~
parse_tcp_hdr_opt.c:19:21: error: 'struct tcphdr' has no member named 'doff'
19 | .pk6_v6.tcp.doff = 9, /* 16 bytes of options */
| ^~~~
Fixes:
cfa7b011894d ("selftests/bpf: tests for using dynptrs to parse skb and xdp buffers")
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/ac5440213c242c62cb4e0d9e0a9cd5058b6a31f6.1721713597.git.tony.ambardar@gmail.com
Tony Ambardar [Tue, 23 Jul 2024 05:54:37 +0000 (22:54 -0700)]
selftests/bpf: Fix include of <sys/fcntl.h>
Update ns_current_pid_tgid.c to use '#include <fcntl.h>' and avoid compile
error against mips64el/musl libc:
In file included from .../prog_tests/ns_current_pid_tgid.c:14:
.../include/sys/fcntl.h:1:2: error: #warning redirecting incorrect #include <sys/fcntl.h> to <fcntl.h> [-Werror=cpp]
1 | #warning redirecting incorrect #include <sys/fcntl.h> to <fcntl.h>
| ^~~~~~~
cc1: all warnings being treated as errors
Fixes:
09c02d553c49 ("bpf, selftests: Fold test_current_pid_tgid_new_ns into test_progs.")
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/8bdc869749177b575025bf69600a4ce591822609.1721713597.git.tony.ambardar@gmail.com
Tony Ambardar [Tue, 23 Jul 2024 05:54:36 +0000 (22:54 -0700)]
selftests/bpf: Fix missing BUILD_BUG_ON() declaration
Explicitly include '<linux/build_bug.h>' to fix errors seen compiling with
gcc targeting mips64el/musl-libc:
user_ringbuf.c: In function 'test_user_ringbuf_loop':
user_ringbuf.c:426:9: error: implicit declaration of function 'BUILD_BUG_ON' [-Werror=implicit-function-declaration]
426 | BUILD_BUG_ON(total_samples <= c_max_entries);
| ^~~~~~~~~~~~
cc1: all warnings being treated as errors
Fixes:
e5a9df51c746 ("selftests/bpf: Add selftests validating the user ringbuf")
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/b28575f9221ec54871c46a2e87612bb4bbf46ccd.1721713597.git.tony.ambardar@gmail.com
Tony Ambardar [Tue, 23 Jul 2024 05:54:35 +0000 (22:54 -0700)]
selftests/bpf: Fix missing UINT_MAX definitions in benchmarks
Include <limits.h> in 'bench.h' to provide a UINT_MAX definition and avoid
multiple compile errors against mips64el/musl-libc like:
benchs/bench_local_storage.c: In function 'parse_arg':
benchs/bench_local_storage.c:40:38: error: 'UINT_MAX' undeclared (first use in this function)
40 | if (ret < 1 || ret > UINT_MAX) {
| ^~~~~~~~
benchs/bench_local_storage.c:11:1: note: 'UINT_MAX' is defined in header '<limits.h>'; did you forget to '#include <limits.h>'?
10 | #include <test_btf.h>
+++ |+#include <limits.h>
11 |
seen with bench_local_storage.c, bench_local_storage_rcu_tasks_trace.c, and
bench_bpf_hashmap_lookup.c.
Fixes:
73087489250d ("selftests/bpf: Add benchmark for local_storage get")
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/8f64a9d9fcff40a7fca090a65a68a9b62a468e16.1721713597.git.tony.ambardar@gmail.com
Tony Ambardar [Tue, 23 Jul 2024 05:54:34 +0000 (22:54 -0700)]
selftests/bpf: Fix missing ARRAY_SIZE() definition in bench.c
Add a "bpf_util.h" include to avoid the following error seen compiling for
mips64el with musl libc:
bench.c: In function 'find_benchmark':
bench.c:590:25: error: implicit declaration of function 'ARRAY_SIZE' [-Werror=implicit-function-declaration]
590 | for (i = 0; i < ARRAY_SIZE(benchs); i++) {
| ^~~~~~~~~~
cc1: all warnings being treated as errors
Fixes:
8e7c2a023ac0 ("selftests/bpf: Add benchmark runner infrastructure")
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/bc4dde77dfcd17a825d8f28f72f3292341966810.1721713597.git.tony.ambardar@gmail.com
Tony Ambardar [Tue, 23 Jul 2024 05:54:31 +0000 (22:54 -0700)]
selftests/bpf: Drop unneeded error.h includes
The addition of general support for unprivileged tests in test_loader.c
breaks building test_verifier on non-glibc (e.g. musl) systems, due to the
inclusion of glibc extension '<error.h>' in 'unpriv_helpers.c'. However,
the header is actually not needed, so remove it to restore building.
Similarly for sk_lookup.c and flow_dissector.c, error.h is not necessary
and causes problems, so drop them.
Fixes:
1d56ade032a4 ("selftests/bpf: Unprivileged tests for test_loader.c")
Fixes:
0ab5539f8584 ("selftests/bpf: Tests for BPF_SK_LOOKUP attach point")
Fixes:
0905beec9f52 ("selftests/bpf: run flow dissector tests in skb-less mode")
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/5664367edf5fea4f3f4b4aec3b182bcfc6edff9c.1721713597.git.tony.ambardar@gmail.com
Tony Ambardar [Tue, 23 Jul 2024 05:54:30 +0000 (22:54 -0700)]
selftests/bpf: Fix error compiling bpf_iter_setsockopt.c with musl libc
Existing code calls getsockname() with a 'struct sockaddr_in6 *' argument
where a 'struct sockaddr *' argument is declared, yielding compile errors
when building for mips64el/musl-libc:
bpf_iter_setsockopt.c: In function 'get_local_port':
bpf_iter_setsockopt.c:98:30: error: passing argument 2 of 'getsockname' from incompatible pointer type [-Werror=incompatible-pointer-types]
98 | if (!getsockname(fd, &addr, &addrlen))
| ^~~~~
| |
| struct sockaddr_in6 *
In file included from .../netinet/in.h:10,
from .../arpa/inet.h:9,
from ./test_progs.h:17,
from bpf_iter_setsockopt.c:5:
.../sys/socket.h:391:23: note: expected 'struct sockaddr * restrict' but argument is of type 'struct sockaddr_in6 *'
391 | int getsockname (int, struct sockaddr *__restrict, socklen_t *__restrict);
| ^
cc1: all warnings being treated as errors
This compiled under glibc only because the argument is declared to be a
"funky" transparent union which includes both types above. Explicitly cast
the argument to allow compiling for both musl and glibc.
Fixes:
eed92afdd14c ("bpf: selftest: Test batching and bpf_(get|set)sockopt in bpf tcp iter")
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Geliang Tang <geliang@kernel.org>
Link: https://lore.kernel.org/bpf/f41def0f17b27a23b1709080e4e3f37f4cc11ca9.1721713597.git.tony.ambardar@gmail.com
Tony Ambardar [Tue, 23 Jul 2024 05:54:29 +0000 (22:54 -0700)]
selftests/bpf: Fix compile error from rlim_t in sk_storage_map.c
Cast 'rlim_t' argument to match expected type of printf() format and avoid
compile errors seen building for mips64el/musl-libc:
In file included from map_tests/sk_storage_map.c:20:
map_tests/sk_storage_map.c: In function 'test_sk_storage_map_stress_free':
map_tests/sk_storage_map.c:414:56: error: format '%lu' expects argument of type 'long unsigned int', but argument 2 has type 'rlim_t' {aka 'long long unsigned int'} [-Werror=format=]
414 | CHECK(err, "setrlimit(RLIMIT_NOFILE)", "rlim_new:%lu errno:%d",
| ^~~~~~~~~~~~~~~~~~~~~~~
415 | rlim_new.rlim_cur, errno);
| ~~~~~~~~~~~~~~~~~
| |
| rlim_t {aka long long unsigned int}
./test_maps.h:12:24: note: in definition of macro 'CHECK'
12 | printf(format); \
| ^~~~~~
map_tests/sk_storage_map.c:414:68: note: format string is defined here
414 | CHECK(err, "setrlimit(RLIMIT_NOFILE)", "rlim_new:%lu errno:%d",
| ~~^
| |
| long unsigned int
| %llu
cc1: all warnings being treated as errors
Fixes:
51a0e301a563 ("bpf: Add BPF_MAP_TYPE_SK_STORAGE test to test_maps")
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1e00a1fa7acf91b4ca135c4102dc796d518bad86.1721713597.git.tony.ambardar@gmail.com
Tony Ambardar [Tue, 23 Jul 2024 05:54:28 +0000 (22:54 -0700)]
selftests/bpf: Use pid_t consistently in test_progs.c
Use pid_t rather than __pid_t when allocating memory for 'worker_pids' in
'struct test_env', as this is its declared type and also avoids compile
errors seen building against musl libc on mipsel64:
test_progs.c:1738:49: error: '__pid_t' undeclared (first use in this function); did you mean 'pid_t'?
1738 | env.worker_pids = calloc(sizeof(__pid_t), env.workers);
| ^~~~~~~
| pid_t
test_progs.c:1738:49: note: each undeclared identifier is reported only once for each function it appears in
Fixes:
91b2c0afd00c ("selftests/bpf: Add parallelism to test_progs")
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Geliang Tang <geliang@kernel.org>
Link: https://lore.kernel.org/bpf/c6447da51a94babc1931711a43e2ceecb135c93d.1721713597.git.tony.ambardar@gmail.com
Ihor Solodrai [Tue, 23 Jul 2024 20:57:43 +0000 (20:57 +0000)]
Alexei Starovoitov [Wed, 24 Jul 2024 03:47:07 +0000 (20:47 -0700)]
Merge branch 'no_caller_saved_registers-attribute-for-helper-calls'
Eduard Zingerman says:
====================
no_caller_saved_registers attribute for helper calls
This patch-set seeks to allow using no_caller_saved_registers gcc/clang
attribute with some BPF helper functions (and kfuncs in the future).
As documented in [1], this attribute means that function scratches
only some of the caller saved registers defined by ABI.
For BPF the set of such registers could be defined as follows:
- R0 is scratched only if function is non-void;
- R1-R5 are scratched only if corresponding parameter type is defined
in the function prototype.
The goal of the patch-set is to implement no_caller_saved_registers
(nocsr for short) in a backwards compatible manner:
- for kernels that support the feature, gain some performance boost
from better register allocation;
- for kernels that don't support the feature, allow programs execution
with minor performance losses.
To achieve this, use a scheme suggested by Alexei Starovoitov:
- for nocsr calls clang allocates registers as-if relevant r0-r5
registers are not scratched by the call;
- as a post-processing step, clang visits each nocsr call and adds
spill/fill for every live r0-r5;
- stack offsets used for spills/fills are allocated as lowest
stack offsets in whole function and are not used for any other
purpose;
- when kernel loads a program, it looks for such patterns
(nocsr function surrounded by spills/fills) and checks if
spill/fill stack offsets are used exclusively in nocsr patterns;
- if so, and if current JIT inlines the call to the nocsr function
(e.g. a helper call), kernel removes unnecessary spill/fill pairs;
- when old kernel loads a program, presence of spill/fill pairs
keeps BPF program valid, albeit slightly less efficient.
Corresponding clang/llvm changes are available in [2].
The patch-set uses bpf_get_smp_processor_id() function as a canary,
making it the first helper with nocsr attribute.
For example, consider the following program:
#define __no_csr __attribute__((no_caller_saved_registers))
#define SEC(name) __attribute__((section(name), used))
#define bpf_printk(fmt, ...) bpf_trace_printk((fmt), sizeof(fmt), __VA_ARGS__)
typedef unsigned int __u32;
static long (* const bpf_trace_printk)(const char *fmt, __u32 fmt_size, ...) = (void *) 6;
static __u32 (*const bpf_get_smp_processor_id)(void) __no_csr = (void *)8;
SEC("raw_tp")
int test(void *ctx)
{
__u32 task = bpf_get_smp_processor_id();
bpf_printk("ctx=%p, smp=%d", ctx, task);
return 0;
}
char _license[] SEC("license") = "GPL";
Compiled (using [2]) as follows:
$ clang --target=bpf -O2 -g -c -o nocsr.bpf.o nocsr.bpf.c
$ llvm-objdump --no-show-raw-insn -Sd nocsr.bpf.o
...
3rd parameter for printk call removable spill/fill pair
.--- 0: r3 = r1 |
; | __u32 task = bpf_get_smp_processor_id(); |
| 1: *(u64 *)(r10 - 0x8) = r3 <----------|
| 2: call 0x8 |
| 3: r3 = *(u64 *)(r10 - 0x8) <----------'
; | bpf_printk("ctx=%p, smp=%d", ctx, task);
| 4: r1 = 0x0 ll
| 6: r2 = 0xf
| 7: r4 = r0
'--> 8: call 0x6
; return 0;
9: r0 = 0x0
10: exit
Here is how the program looks after verifier processing:
# bpftool prog load ./nocsr.bpf.o /sys/fs/bpf/nocsr-test
# bpftool prog dump xlated pinned /sys/fs/bpf/nocsr-test
int test(void * ctx):
0: (bf) r3 = r1 <--- 3rd printk parameter
; __u32 task = bpf_get_smp_processor_id();
1: (b4) w0 = 197324 <--. inlined helper call,
2: (bf) r0 = &(void __percpu *)(r0) <--- spill/fill
3: (61) r0 = *(u32 *)(r0 +0) <--' pair removed
; bpf_printk("ctx=%p, smp=%d", ctx, task);
4: (18) r1 = map[id:5][0]+0
6: (b7) r2 = 15
7: (bf) r4 = r0
8: (85) call bpf_trace_printk#-125920
; return 0;
9: (b7) r0 = 0
10: (95) exit
[1] https://clang.llvm.org/docs/AttributeReference.html#no-caller-saved-registers
[2] https://github.com/eddyz87/llvm-project/tree/bpf-no-caller-saved-registers
Change list:
- v3 -> v4:
- When nocsr spills/fills are removed in the subprogram, allow these
spills/fills to reside in [-MAX_BPF_STACK-48..MAX_BPF_STACK) range
(suggested by Alexei);
- Dropped patches with special handling for bpf_probe_read_kernel()
(requested by Alexei);
- Reset aux .nocsr_pattern and .nocsr_spills_num fields in
check_nocsr_stack_contract() (requested by Andrii).
Andrii, I have not added an additional flag to
struct bpf_subprog_info, it currently does not have holes
and I really don't like adding a bool field there just as an
alternative indicator that nocsr is disabled.
Indicator at the moment:
- nocsr_stack_off >= S16_MIN means that nocsr rewrite is enabled;
- nocsr_stack_off == S16_MIN means that nocsr rewrite is disabled.
- v2 -> v3:
- As suggested by Andrii, 'nocsr_stack_off' is no longer checked at
rewrite time, instead mark_nocsr_patterns() now does two passes
over BPF program:
- on a first pass it computes the lowest stack spill offset for
the subprogram;
- on a second pass this offset is used to recognize nocsr pattern.
- As suggested by Alexei, a new mechanic is added to work around a
situation mentioned by Andrii, when more helper functions are
marked as nocsr at compile time than current kernel supports:
- all {spill*,helper call,fill*} patterns are now marked as
insn_aux_data[*].nocsr_pattern, thus relaxing failure condition
for check_nocsr_stack_contract();
- spill/fill pairs are not removed for patterns where helper can't
be inlined;
- see mark_nocsr_pattern_for_call() for details an example.
- As suggested by Alexei, subprogram stack depth is now adjusted
if all spill/fill pairs could be removed. This adjustment has
to take place before optimize_bpf_loop(), hence the rewrite
is moved from do_misc_fixups() to remove_nocsr_spills_fills()
(again).
- As suggested by Andrii, special measures are taken to work around
bpf_probe_read_kernel() access to BPF stack, see patches 11, 12.
Patch #11 is very simplistic, a more comprehensive solution would
be to change the type of the third parameter of the
bpf_probe_read_kernel() from ARG_ANYTHING to something else and
not only check nocsr contract, but also propagate stack slot
liveness information. However, such change would require update in
struct bpf_call_arg_meta processing, which currently implies that
every memory parameter is followed by a size parameter.
I can work on these changes, please comment.
- Stylistic changes suggested by Andrii.
- Added acks from Andrii.
- Dropped RFC tag.
- v1 -> v2:
- assume that functions inlined by either jit or verifier
conform to no_caller_saved_registers contract (Andrii, Puranjay);
- allow nocsr rewrite for bpf_get_smp_processor_id()
on arm64 and riscv64 architectures (Puranjay);
- __arch_{x86_64,arm64,riscv64} macro for test_loader;
- moved remove_nocsr_spills_fills() inside do_misc_fixups() (Andrii);
- moved nocsr pattern detection from check_cfg() to a separate pass
(Andrii);
- various stylistic/correctness changes according to Andrii's
comments.
Revisions:
- v1 https://lore.kernel.org/bpf/
20240629094733.
3863850-1-eddyz87@gmail.com/
- v2 https://lore.kernel.org/bpf/
20240704102402.
1644916-1-eddyz87@gmail.com/
- v3 https://lore.kernel.org/bpf/
20240715230201.
3901423-1-eddyz87@gmail.com/
====================
Link: https://lore.kernel.org/r/20240722233844.1406874-1-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Eduard Zingerman [Mon, 22 Jul 2024 23:38:44 +0000 (16:38 -0700)]
selftests/bpf: test no_caller_saved_registers spill/fill removal
Tests for no_caller_saved_registers processing logic
(see verifier.c:match_and_mark_nocsr_pattern()):
- a canary positive test case;
- a canary test case for arm64 and riscv64;
- various tests with broken patterns;
- tests with read/write fixed/varying stack access that violate nocsr
stack access contract;
- tests with multiple subprograms;
- tests using nocsr in combination with may_goto/bpf_loop,
as all of these features affect stack depth;
- tests for nocsr stack spills below max stack depth.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240722233844.1406874-11-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Eduard Zingerman [Mon, 22 Jul 2024 23:38:43 +0000 (16:38 -0700)]
selftests/bpf: __arch_* macro to limit test cases to specific archs
Add annotations __arch_x86_64, __arch_arm64, __arch_riscv64
to specify on which architecture the test case should be tested.
Several __arch_* annotations could be specified at once.
When test case is not run on current arch it is marked as skipped.
For example, the following would be tested only on arm64 and riscv64:
SEC("raw_tp")
__arch_arm64
__arch_riscv64
__xlated("1: *(u64 *)(r10 - 16) = r1")
__xlated("2: call")
__xlated("3: r1 = *(u64 *)(r10 - 16);")
__success
__naked void canary_arm64_riscv64(void)
{
asm volatile (
"r1 = 1;"
"*(u64 *)(r10 - 16) = r1;"
"call %[bpf_get_smp_processor_id];"
"r1 = *(u64 *)(r10 - 16);"
"exit;"
:
: __imm(bpf_get_smp_processor_id)
: __clobber_all);
}
On x86 it would be skipped:
#467/2 verifier_nocsr/canary_arm64_riscv64:SKIP
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240722233844.1406874-10-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Eduard Zingerman [Mon, 22 Jul 2024 23:38:42 +0000 (16:38 -0700)]
selftests/bpf: allow checking xlated programs in verifier_* tests
Add a macro __xlated("...") for use with test_loader tests.
When such annotations are present for the test case:
- bpf_prog_get_info_by_fd() is used to get BPF program after all
rewrites are applied by verifier.
- the program is disassembled and patterns specified in __xlated are
searched for in the disassembly text.
__xlated matching follows the same mechanics as __msg:
each subsequent pattern is matched from the point where
previous pattern ended.
This allows to write tests like below, where the goal is to verify the
behavior of one of the of the transformations applied by verifier:
SEC("raw_tp")
__xlated("1: w0 = ")
__xlated("2: r0 = &(void __percpu *)(r0)")
__xlated("3: r0 = *(u32 *)(r0 +0)")
__xlated("4: exit")
__success __naked void simple(void)
{
asm volatile (
"call %[bpf_get_smp_processor_id];"
"exit;"
:
: __imm(bpf_get_smp_processor_id)
: __clobber_all);
}
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240722233844.1406874-9-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Eduard Zingerman [Mon, 22 Jul 2024 23:38:41 +0000 (16:38 -0700)]
selftests/bpf: extract test_loader->expect_msgs as a data structure
Non-functional change: use a separate data structure to represented
expected messages in test_loader.
This would allow to use the same functionality for expected set of
disassembled instructions in the follow-up commit.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240722233844.1406874-8-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Eduard Zingerman [Mon, 22 Jul 2024 23:38:40 +0000 (16:38 -0700)]
selftests/bpf: no need to track next_match_pos in struct test_loader
The call stack for validate_case() function looks as follows:
- test_loader__run_subtests()
- process_subtest()
- run_subtest()
- prepare_case(), which does 'tester->next_match_pos = 0';
- validate_case(), which increments tester->next_match_pos.
Hence, each subtest is run with next_match_pos freshly set to zero.
Meaning that there is no need to persist this variable in the
struct test_loader, use local variable instead.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240722233844.1406874-7-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Eduard Zingerman [Mon, 22 Jul 2024 23:38:39 +0000 (16:38 -0700)]
selftests/bpf: print correct offset for pseudo calls in disasm_insn()
Adjust disasm_helpers.c:disasm_insn() to account for the following
part of the verifier.c:jit_subprogs:
for (i = 0, insn = prog->insnsi; i < prog->len; i++, insn++) {
/* ... */
if (!bpf_pseudo_call(insn))
continue;
insn->off = env->insn_aux_data[i].call_imm;
subprog = find_subprog(env, i + insn->off + 1);
insn->imm = subprog;
}
Where verifier moves offset of the subprogram to the insn->off field.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240722233844.1406874-6-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Yonghong Song [Tue, 23 Jul 2024 16:29:40 +0000 (09:29 -0700)]
selftests/bpf: Add reg_bounds tests for ldsx and subreg compare
Add a few reg_bounds selftests to test 32/16/8-bit ldsx and subreg comparison.
Without the previous patch, all added tests will fail.
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240723162940.2732171-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Eduard Zingerman [Mon, 22 Jul 2024 23:38:38 +0000 (16:38 -0700)]
selftests/bpf: extract utility function for BPF disassembly
struct bpf_insn *disasm_insn(struct bpf_insn *insn, char *buf, size_t buf_sz);
Disassembles instruction 'insn' to a text buffer 'buf'.
Removes insn->code hex prefix added by kernel disassembly routine.
Returns a pointer to the next instruction
(increments insn by either 1 or 2).
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240722233844.1406874-5-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Yonghong Song [Tue, 23 Jul 2024 16:29:33 +0000 (09:29 -0700)]
bpf: Get better reg range with ldsx and 32bit compare
With latest llvm19, the selftest iters/iter_arr_with_actual_elem_count
failed with -mcpu=v4.
The following are the details:
0: R1=ctx() R10=fp0
; int iter_arr_with_actual_elem_count(const void *ctx) @ iters.c:1420
0: (b4) w7 = 0 ; R7_w=0
; int i, n = loop_data.n, sum = 0; @ iters.c:1422
1: (18) r1 = 0xffffc90000191478 ; R1_w=map_value(map=iters.bss,ks=4,vs=1280,off=1144)
3: (61) r6 = *(u32 *)(r1 +128) ; R1_w=map_value(map=iters.bss,ks=4,vs=1280,off=1144) R6_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff))
; if (n > ARRAY_SIZE(loop_data.data)) @ iters.c:1424
4: (26) if w6 > 0x20 goto pc+27 ; R6_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=32,var_off=(0x0; 0x3f))
5: (bf) r8 = r10 ; R8_w=fp0 R10=fp0
6: (07) r8 += -8 ; R8_w=fp-8
; bpf_for(i, 0, n) { @ iters.c:1427
7: (bf) r1 = r8 ; R1_w=fp-8 R8_w=fp-8
8: (b4) w2 = 0 ; R2_w=0
9: (bc) w3 = w6 ; R3_w=scalar(id=1,smin=smin32=0,smax=umax=smax32=umax32=32,var_off=(0x0; 0x3f)) R6_w=scalar(id=1,smin=smin32=0,smax=umax=smax32=umax32=32,var_off=(0x0; 0x3f))
10: (85) call bpf_iter_num_new#45179 ; R0=scalar() fp-8=iter_num(ref_id=2,state=active,depth=0) refs=2
11: (bf) r1 = r8 ; R1=fp-8 R8=fp-8 refs=2
12: (85) call bpf_iter_num_next#45181 13: R0=rdonly_mem(id=3,ref_obj_id=2,sz=4) R6=scalar(id=1,smin=smin32=0,smax=umax=smax32=umax32=32,var_off=(0x0; 0x3f)) R7=0 R8=fp-8 R10=fp0 fp-8=iter_num(ref_id=2,state=active,depth=1) refs=2
; bpf_for(i, 0, n) { @ iters.c:1427
13: (15) if r0 == 0x0 goto pc+2 ; R0=rdonly_mem(id=3,ref_obj_id=2,sz=4) refs=2
14: (81) r1 = *(s32 *)(r0 +0) ; R0=rdonly_mem(id=3,ref_obj_id=2,sz=4) R1_w=scalar(smin=0xffffffff80000000,smax=0x7fffffff) refs=2
15: (ae) if w1 < w6 goto pc+4 20: R0=rdonly_mem(id=3,ref_obj_id=2,sz=4) R1=scalar(smin=0xffffffff80000000,smax=smax32=umax32=31,umax=0xffffffff0000001f,smin32=0,var_off=(0x0; 0xffffffff0000001f)) R6=scalar(id=1,smin=umin=smin32=umin32=1,smax=umax=smax32=umax32=32,var_off=(0x0; 0x3f)) R7=0 R8=fp-8 R10=fp0 fp-8=iter_num(ref_id=2,state=active,depth=1) refs=2
; sum += loop_data.data[i]; @ iters.c:1429
20: (67) r1 <<= 2 ; R1_w=scalar(smax=0x7ffffffc0000007c,umax=0xfffffffc0000007c,smin32=0,smax32=umax32=124,var_off=(0x0; 0xfffffffc0000007c)) refs=2
21: (18) r2 = 0xffffc90000191478 ; R2_w=map_value(map=iters.bss,ks=4,vs=1280,off=1144) refs=2
23: (0f) r2 += r1
math between map_value pointer and register with unbounded min value is not allowed
The source code:
int iter_arr_with_actual_elem_count(const void *ctx)
{
int i, n = loop_data.n, sum = 0;
if (n > ARRAY_SIZE(loop_data.data))
return 0;
bpf_for(i, 0, n) {
/* no rechecking of i against ARRAY_SIZE(loop_data.n) */
sum += loop_data.data[i];
}
return sum;
}
The insn #14 is a sign-extenstion load which is related to 'int i'.
The insn #15 did a subreg comparision. Note that smin=0xffffffff80000000 and this caused later
insn #23 failed verification due to unbounded min value.
Actually insn #15 R1 smin range can be better. Before insn #15, we have
R1_w=scalar(smin=0xffffffff80000000,smax=0x7fffffff)
With the above range, we know for R1, upper 32bit can only be 0xffffffff or 0.
Otherwise, the value range for R1 could be beyond [smin=0xffffffff80000000,smax=0x7fffffff].
After insn #15, for the true patch, we know smin32=0 and smax32=32. With the upper 32bit 0xffffffff,
then the corresponding value is [0xffffffff00000000, 0xffffffff00000020]. The range is
obviously beyond the original range [smin=0xffffffff80000000,smax=0x7fffffff] and the
range is not possible. So the upper 32bit must be 0, which implies smin = smin32 and
smax = smax32.
This patch fixed the issue by adding additional register deduction after 32-bit compare
insn. If the signed 32-bit register range is non-negative then 64-bit smin is
in range of [S32_MIN, S32_MAX], then the actual 64-bit smin/smax should be the same
as 32-bit smin32/smax32.
With this patch, iters/iter_arr_with_actual_elem_count succeeded with better register range:
from 15 to 20: R0=rdonly_mem(id=7,ref_obj_id=2,sz=4) R1_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=31,var_off=(0x0; 0x1f)) R6=scalar(id=1,smin=umin=smin32=umin32=1,smax=umax=smax32=umax32=32,var_off=(0x0; 0x3f)) R7=scalar(id=9,smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) R8=scalar(id=9,smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) R10=fp0 fp-8=iter_num(ref_id=2,state=active,depth=3) refs=2
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240723162933.2731620-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Eduard Zingerman [Mon, 22 Jul 2024 23:38:37 +0000 (16:38 -0700)]
bpf, x86, riscv, arm: no_caller_saved_registers for bpf_get_smp_processor_id()
The function bpf_get_smp_processor_id() is processed in a different
way, depending on the arch:
- on x86 verifier replaces call to bpf_get_smp_processor_id() with a
sequence of instructions that modify only r0;
- on riscv64 jit replaces call to bpf_get_smp_processor_id() with a
sequence of instructions that modify only r0;
- on arm64 jit replaces call to bpf_get_smp_processor_id() with a
sequence of instructions that modify only r0 and tmp registers.
These rewrites satisfy attribute no_caller_saved_registers contract.
Allow rewrite of no_caller_saved_registers patterns for
bpf_get_smp_processor_id() in order to use this function as a canary
for no_caller_saved_registers tests.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240722233844.1406874-4-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Yonghong Song [Tue, 23 Jul 2024 15:34:44 +0000 (08:34 -0700)]
selftests/bpf: Add tests for ldsx of pkt data/data_end/data_meta accesses
The following tests are added to verifier_ldsx.c:
- sign extension of data/data_end/data_meta for tcx programs.
The actual checking is in bpf_skb_is_valid_access() which
is called by sk_filter, cg_skb, lwt, tc(tcx) and sk_skb.
- sign extension of data/data_end/data_meta for xdp programs.
- sign extension of data/data_end for flow_dissector programs.
All newly-added tests have verification failure with message
"invalid bpf_context access". Without previous patch, all these
tests succeeded verification.
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240723153444.2430365-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Eduard Zingerman [Mon, 22 Jul 2024 23:38:36 +0000 (16:38 -0700)]
bpf: no_caller_saved_registers attribute for helper calls
GCC and LLVM define a no_caller_saved_registers function attribute.
This attribute means that function scratches only some of
the caller saved registers defined by ABI.
For BPF the set of such registers could be defined as follows:
- R0 is scratched only if function is non-void;
- R1-R5 are scratched only if corresponding parameter type is defined
in the function prototype.
This commit introduces flag bpf_func_prot->allow_nocsr.
If this flag is set for some helper function, verifier assumes that
it follows no_caller_saved_registers calling convention.
The contract between kernel and clang allows to simultaneously use
such functions and maintain backwards compatibility with old
kernels that don't understand no_caller_saved_registers calls
(nocsr for short):
- clang generates a simple pattern for nocsr calls, e.g.:
r1 = 1;
r2 = 2;
*(u64 *)(r10 - 8) = r1;
*(u64 *)(r10 - 16) = r2;
call %[to_be_inlined]
r2 = *(u64 *)(r10 - 16);
r1 = *(u64 *)(r10 - 8);
r0 = r1;
r0 += r2;
exit;
- kernel removes unnecessary spills and fills, if called function is
inlined by verifier or current JIT (with assumption that patch
inserted by verifier or JIT honors nocsr contract, e.g. does not
scratch r3-r5 for the example above), e.g. the code above would be
transformed to:
r1 = 1;
r2 = 2;
call %[to_be_inlined]
r0 = r1;
r0 += r2;
exit;
Technically, the transformation is split into the following phases:
- function mark_nocsr_patterns(), called from bpf_check()
searches and marks potential patterns in instruction auxiliary data;
- upon stack read or write access,
function check_nocsr_stack_contract() is used to verify if
stack offsets, presumably reserved for nocsr patterns, are used
only from those patterns;
- function remove_nocsr_spills_fills(), called from bpf_check(),
applies the rewrite for valid patterns.
See comment in mark_nocsr_pattern_for_call() for more details.
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240722233844.1406874-3-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Yonghong Song [Tue, 23 Jul 2024 15:34:39 +0000 (08:34 -0700)]
bpf: Fail verification for sign-extension of packet data/data_end/data_meta
syzbot reported a kernel crash due to
commit
1f1e864b6555 ("bpf: Handle sign-extenstin ctx member accesses").
The reason is due to sign-extension of 32-bit load for
packet data/data_end/data_meta uapi field.
The original code looks like:
r2 = *(s32 *)(r1 + 76) /* load __sk_buff->data */
r3 = *(u32 *)(r1 + 80) /* load __sk_buff->data_end */
r0 = r2
r0 += 8
if r3 > r0 goto +1
...
Note that __sk_buff->data load has 32-bit sign extension.
After verification and convert_ctx_accesses(), the final asm code looks like:
r2 = *(u64 *)(r1 +208)
r2 = (s32)r2
r3 = *(u64 *)(r1 +80)
r0 = r2
r0 += 8
if r3 > r0 goto pc+1
...
Note that 'r2 = (s32)r2' may make the kernel __sk_buff->data address invalid
which may cause runtime failure.
Currently, in C code, typically we have
void *data = (void *)(long)skb->data;
void *data_end = (void *)(long)skb->data_end;
...
and it will generate
r2 = *(u64 *)(r1 +208)
r3 = *(u64 *)(r1 +80)
r0 = r2
r0 += 8
if r3 > r0 goto pc+1
If we allow sign-extension,
void *data = (void *)(long)(int)skb->data;
void *data_end = (void *)(long)skb->data_end;
...
the generated code looks like
r2 = *(u64 *)(r1 +208)
r2 <<= 32
r2 s>>= 32
r3 = *(u64 *)(r1 +80)
r0 = r2
r0 += 8
if r3 > r0 goto pc+1
and this will cause verification failure since "r2 <<= 32" is not allowed
as "r2" is a packet pointer.
To fix this issue for case
r2 = *(s32 *)(r1 + 76) /* load __sk_buff->data */
this patch added additional checking in is_valid_access() callback
function for packet data/data_end/data_meta access. If those accesses
are with sign-extenstion, the verification will fail.
[1] https://lore.kernel.org/bpf/
000000000000c90eee061d236d37@google.com/
Reported-by: syzbot+ad9ec60c8eaf69e6f99c@syzkaller.appspotmail.com
Fixes:
1f1e864b6555 ("bpf: Handle sign-extenstin ctx member accesses")
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240723153439.2429035-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Eduard Zingerman [Mon, 22 Jul 2024 23:38:35 +0000 (16:38 -0700)]
bpf: add a get_helper_proto() utility function
Extract the part of check_helper_call() as a utility function allowing
to query 'struct bpf_func_proto' for a specific helper function id.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240722233844.1406874-2-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tony Ambardar [Tue, 23 Jul 2024 00:30:45 +0000 (17:30 -0700)]
tools/runqslower: Fix LDFLAGS and add LDLIBS support
Actually use previously defined LDFLAGS during build and add support for
LDLIBS to link extra standalone libraries e.g. 'argp' which is not provided
by musl libc.
Fixes:
585bf4640ebe ("tools: runqslower: Add EXTRA_CFLAGS and EXTRA_LDFLAGS support")
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/bpf/20240723003045.2273499-1-tony.ambardar@gmail.com
Tony Ambardar [Sat, 20 Jul 2024 05:25:35 +0000 (22:25 -0700)]
selftests/bpf: Fix wrong binary in Makefile log output
Make log output incorrectly shows 'test_maps' as the binary name for every
'CLNG-BPF' build step, apparently picking up the last value defined for the
$(TRUNNER_BINARY) variable. Update the 'CLANG_BPF_BUILD_RULE' variants to
fix this confusing output.
Current output:
CLNG-BPF [test_maps] access_map_in_map.bpf.o
GEN-SKEL [test_progs] access_map_in_map.skel.h
...
CLNG-BPF [test_maps] access_map_in_map.bpf.o
GEN-SKEL [test_progs-no_alu32] access_map_in_map.skel.h
...
CLNG-BPF [test_maps] access_map_in_map.bpf.o
GEN-SKEL [test_progs-cpuv4] access_map_in_map.skel.h
After fix:
CLNG-BPF [test_progs] access_map_in_map.bpf.o
GEN-SKEL [test_progs] access_map_in_map.skel.h
...
CLNG-BPF [test_progs-no_alu32] access_map_in_map.bpf.o
GEN-SKEL [test_progs-no_alu32] access_map_in_map.skel.h
...
CLNG-BPF [test_progs-cpuv4] access_map_in_map.bpf.o
GEN-SKEL [test_progs-cpuv4] access_map_in_map.skel.h
Fixes:
a5d0c26a2784 ("selftests/bpf: Add a cpuv4 test runner for cpu=v4 testing")
Fixes:
89ad7420b25c ("selftests/bpf: Drop the need for LLVM's llc")
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20240720052535.2185967-1-tony.ambardar@gmail.com
Andrii Nakryiko [Tue, 23 Jul 2024 20:21:25 +0000 (13:21 -0700)]
Merge branch 'selftests-bpf-add-more-uprobe-multi-tests'
Jiri Olsa says:
====================
selftests/bpf: Add more uprobe multi tests
hi,
adding more uprobe multi tests for failed attachments
inside the uprobe register code.
v3 changes:
- renamed several variables/functions, null check [Andrii]
- fixed CI issue
thanks,
jirka
---
====================
Link: https://lore.kernel.org/r/20240722202758.3889061-1-jolsa@kernel.org
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Artem Savkov [Tue, 23 Jul 2024 07:10:31 +0000 (09:10 +0200)]
selftests/bpf: Fix compilation failure when CONFIG_NET_FOU!=y
Without CONFIG_NET_FOU bpf selftests are unable to build because of
missing definitions. Add ___local versions of struct bpf_fou_encap and
enum bpf_fou_encap_type to fix the issue.
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240723071031.3389423-1-asavkov@redhat.com
Jiri Olsa [Mon, 22 Jul 2024 20:27:58 +0000 (22:27 +0200)]
selftests/bpf: Add uprobe multi consumers test
Adding test that attaches/detaches multiple consumers on
single uprobe and verifies all were hit as expected.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240722202758.3889061-3-jolsa@kernel.org
Tony Ambardar [Tue, 23 Jul 2024 00:13:29 +0000 (17:13 -0700)]
selftests/bpf: Fix error linking uprobe_multi on mips
Linking uprobe_multi.c on mips64el fails due to relocation overflows, when
the GOT entries required exceeds the default maximum. Add a specific CFLAGS
(-mxgot) for uprobe_multi.c on MIPS that allows using a larger GOT and
avoids errors such as:
/tmp/ccBTNQzv.o: in function `bench':
uprobe_multi.c:49:(.text+0x1d7720): relocation truncated to fit: R_MIPS_GOT_DISP against `uprobe_multi_func_08188'
uprobe_multi.c:49:(.text+0x1d7730): relocation truncated to fit: R_MIPS_GOT_DISP against `uprobe_multi_func_08189'
...
collect2: error: ld returned 1 exit status
Fixes:
519dfeaf5119 ("selftests/bpf: Add uprobe_multi test program")
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/14eb7b70f8ccef9834874d75eb373cb9292129da.1721692479.git.tony.ambardar@gmail.com
Jiri Olsa [Mon, 22 Jul 2024 20:27:57 +0000 (22:27 +0200)]
selftests/bpf: Add uprobe fail tests for uprobe multi
Adding tests for checking on recovery after failing to
attach uprobe.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240722202758.3889061-2-jolsa@kernel.org
Tony Ambardar [Tue, 23 Jul 2024 00:13:28 +0000 (17:13 -0700)]
selftests/bpf: Add missing system defines for mips
Update get_sys_includes in Makefile with missing MIPS-related definitions
to fix many, many compilation errors building selftests/bpf. The following
added defines drive conditional logic in system headers for word-size and
endianness selection:
MIPSEL, MIPSEB
_MIPS_SZPTR
_MIPS_SZLONG
_MIPS_SIM, _ABIO32, _ABIN32, _ABI64
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/f3cfceaf5299cdd2ac0e0a36072d6ca7be23e603.1721692479.git.tony.ambardar@gmail.com
Ihor Solodrai [Tue, 23 Jul 2024 03:07:00 +0000 (03:07 +0000)]
Song Liu [Tue, 23 Jul 2024 05:14:55 +0000 (22:14 -0700)]
selftests/bpf: Add a test for mmap-able map in map
Regular BPF hash map is not mmap-able from user space. However, map-in-map
with outer map of type BPF_MAP_TYPE_HASH_OF_MAPS and mmap-able array as
inner map can perform similar operations as a mmap-able hash map. This
can be used by applications that benefit from fast accesses to some local
data.
Add a selftest to show this use case.
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240723051455.1589192-1-song@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Martin KaFai Lau [Tue, 23 Jul 2024 17:45:51 +0000 (10:45 -0700)]
Merge branch 'use network helpers, part 10'
Geliang Tang says:
====================
This set is part 10 of series "use network helpers" all BPF selftests
wide.
Patches 1-3 drop local functions make_client(), make_socket() and
inetaddr_len() in sk_lookup.c. Patch 4 drops a useless function
__start_server() in network_helpers.c.
====================
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Geliang Tang [Sat, 20 Jul 2024 11:40:06 +0000 (19:40 +0800)]
selftests/bpf: Drop __start_server in network_helpers
The helper start_server_addr() is a wrapper of __start_server(), the
only difference between them is __start_server() accepts a sockaddr type
address parameter, but start_server_addr() accepts a sockaddr_storage one.
This patch drops __start_server(), and updates the callers to invoke
start_server_addr() instead.
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Link: https://lore.kernel.org/r/31399df7cb957b7c233e79963b0aa0dc4278d273.1721475357.git.tanggeliang@kylinos.cn
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Geliang Tang [Sat, 20 Jul 2024 11:40:05 +0000 (19:40 +0800)]
selftests/bpf: Drop inetaddr_len in sk_lookup
No need to use a dedicated helper inetaddr_len() to get the length of
the IPv4 or IPv6 address, it can be got by make_sockaddr(), this patch
drops it.
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Link: https://lore.kernel.org/r/32e2a4122921051da38a6e4fbb2ebee5f0af5a4e.1721475357.git.tanggeliang@kylinos.cn
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Geliang Tang [Sat, 20 Jul 2024 11:40:04 +0000 (19:40 +0800)]
selftests/bpf: Drop make_socket in sk_lookup
This patch uses the public network helers client_socket() + make_sockaddr()
in sk_lookup.c to create the client socket, set the timeout sockopts, and
make the connecting address. The local defined function make_socket()
can be dropped then.
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Link: https://lore.kernel.org/r/588771977ac48c27f73526d8421a84b91d7cf218.1721475357.git.tanggeliang@kylinos.cn
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Geliang Tang [Sat, 20 Jul 2024 11:40:03 +0000 (19:40 +0800)]
selftests/bpf: Drop make_client in sk_lookup
This patch uses the new helper connect_to_addr_str() in sk_lookup.c to
create the client socket and connect to the server, instead of using local
defined function make_client(). This local function can be dropped then.
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Link: https://lore.kernel.org/r/058199d7ab46802249dae066ca22c98f6be508ee.1721475357.git.tanggeliang@kylinos.cn
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Alexei Starovoitov [Tue, 23 Jul 2024 02:08:15 +0000 (19:08 -0700)]
selftests/bpf: Workaround strict bpf_lsm return value check.
test_progs-no_alu32 -t libbpf_get_fd_by_id_opts
is being rejected by the verifier with the following error
due to compiler optimization:
6: (67) r0 <<= 62 ; R0_w=scalar(smax=0x4000000000000000,umax=0xc000000000000000,smin32=0,smax32=umax32=0,var_off=(0x0; 0xc000000000000000))
7: (c7) r0 s>>= 63 ; R0_w=scalar(smin=smin32=-1,smax=smax32=0)
; @ test_libbpf_get_fd_by_id_opts.c:0
8: (57) r0 &= -13 ; R0_w=scalar(smax=0x7ffffffffffffff3,umax=0xfffffffffffffff3,smax32=0x7ffffff3,umax32=0xfffffff3,var_off=(0x0; 0xfffffffffffffff3))
; int BPF_PROG(check_access, struct bpf_map *map, fmode_t fmode) @ test_libbpf_get_fd_by_id_opts.c:27
9: (95) exit
At program exit the register R0 has smax=
9223372036854775795 should have been in [-4095, 0]
Workaround by adding barrier().
Eventually the verifier will be able to recognize it.
Fixes:
5d99e198be27 ("bpf, lsm: Add check for BPF LSM return value")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Alexei Starovoitov [Tue, 23 Jul 2024 00:33:28 +0000 (17:33 -0700)]
Merge branch 'add-bpf-lsm-return-value-range-check-bpf-part'
Xu Kuohai says:
====================
Add BPF LSM return value range check, BPF part
From: Xu Kuohai <xukuohai@huawei.com>
LSM BPF prog may make kernel panic when returning an unexpected value,
such as returning positive value on hook file_alloc_security.
To fix it, series [1] refactored LSM hook return values and added
BPF return value check on top of that. Since the refactoring of LSM
hooks and checking BPF prog return value patches is not closely related,
this series separates BPF-related patches from [1].
v2:
- Update Shung-Hsi's patch with [3]
v1: https://lore.kernel.org/bpf/
20240719081749.769748-1-xukuohai@huaweicloud.com/
Changes to [1]:
1. Extend LSM disabled list to include hooks refactored in [1] to avoid
dependency on the hooks return value refactoring patches.
2. Replace the special case patch for bitwise AND on [-1, 0] with Shung-Hsi's
general bitwise AND improvement patch [2].
3. Remove unused patches.
[1] https://lore.kernel.org/bpf/
20240711111908.
3817636-1-xukuohai@huaweicloud.com
https://lore.kernel.org/bpf/
20240711113828.
3818398-1-xukuohai@huaweicloud.com
[2] https://lore.kernel.org/bpf/ykuhustu7vt2ilwhl32kj655xfdgdlm2xkl5rff6tw2ycksovp@ss2n4gpjysnw
[3] https://lore.kernel.org/bpf/
20240719081702.137173-1-shung-hsi.yu@suse.com/
Shung-Hsi Yu (1):
bpf, verifier: improve signed ranges inference for BPF_AND
====================
Link: https://lore.kernel.org/r/20240719110059.797546-1-xukuohai@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Xu Kuohai [Fri, 19 Jul 2024 11:00:59 +0000 (19:00 +0800)]
selftests/bpf: Add verifier tests for bpf lsm
Add verifier tests to check bpf lsm return values and disabled hooks.
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Link: https://lore.kernel.org/r/20240719110059.797546-10-xukuohai@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Xu Kuohai [Fri, 19 Jul 2024 11:00:58 +0000 (19:00 +0800)]
selftests/bpf: Add test for lsm tail call
Add test for lsm tail call to ensure tail call can only be used between
bpf lsm progs attached to the same hook.
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Link: https://lore.kernel.org/r/20240719110059.797546-9-xukuohai@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Xu Kuohai [Fri, 19 Jul 2024 11:00:57 +0000 (19:00 +0800)]
selftests/bpf: Add return value checks for failed tests
The return ranges of some bpf lsm test progs can not be deduced by
the verifier accurately. To avoid erroneous rejections, add explicit
return value checks for these progs.
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Link: https://lore.kernel.org/r/20240719110059.797546-8-xukuohai@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Xu Kuohai [Fri, 19 Jul 2024 11:00:56 +0000 (19:00 +0800)]
selftests/bpf: Avoid load failure for token_lsm.c
The compiler optimized the two bpf progs in token_lsm.c to make return
value from the bool variable in the "return -1" path, causing an
unexpected rejection:
0: R1=ctx() R10=fp0
; int BPF_PROG(bpf_token_capable, struct bpf_token *token, int cap) @ bpf_lsm.c:17
0: (b7) r6 = 0 ; R6_w=0
; if (my_pid == 0 || my_pid != (bpf_get_current_pid_tgid() >> 32)) @ bpf_lsm.c:19
1: (18) r1 = 0xffffc9000102a000 ; R1_w=map_value(map=bpf_lsm.bss,ks=4,vs=5)
3: (61) r7 = *(u32 *)(r1 +0) ; R1_w=map_value(map=bpf_lsm.bss,ks=4,vs=5) R7_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff))
4: (15) if r7 == 0x0 goto pc+11 ; R7_w=scalar(smin=umin=umin32=1,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff))
5: (67) r7 <<= 32 ; R7_w=scalar(smax=0x7fffffff00000000,umax=0xffffffff00000000,smin32=0,smax32=umax32=0,var_off=(0x0; 0xffffffff00000000))
6: (c7) r7 s>>= 32 ; R7_w=scalar(smin=0xffffffff80000000,smax=0x7fffffff)
7: (85) call bpf_get_current_pid_tgid#14 ; R0=scalar()
8: (77) r0 >>= 32 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff))
9: (5d) if r0 != r7 goto pc+6 ; R0_w=scalar(smin=smin32=0,smax=umax=umax32=0x7fffffff,var_off=(0x0; 0x7fffffff)) R7=scalar(smin=smin32=0,smax=umax=umax32=0x7fffffff,var_off=(0x0; 0x7fffffff))
; if (reject_capable) @ bpf_lsm.c:21
10: (18) r1 = 0xffffc9000102a004 ; R1_w=map_value(map=bpf_lsm.bss,ks=4,vs=5,off=4)
12: (71) r6 = *(u8 *)(r1 +0) ; R1_w=map_value(map=bpf_lsm.bss,ks=4,vs=5,off=4) R6_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=255,var_off=(0x0; 0xff))
; @ bpf_lsm.c:0
13: (87) r6 = -r6 ; R6_w=scalar()
14: (67) r6 <<= 56 ; R6_w=scalar(smax=0x7f00000000000000,umax=0xff00000000000000,smin32=0,smax32=umax32=0,var_off=(0x0; 0xff00000000000000))
15: (c7) r6 s>>= 56 ; R6_w=scalar(smin=smin32=-128,smax=smax32=127)
; int BPF_PROG(bpf_token_capable, struct bpf_token *token, int cap) @ bpf_lsm.c:17
16: (bf) r0 = r6 ; R0_w=scalar(id=1,smin=smin32=-128,smax=smax32=127) R6_w=scalar(id=1,smin=smin32=-128,smax=smax32=127)
17: (95) exit
At program exit the register R0 has smin=-128 smax=127 should have been in [-4095, 0]
To avoid this failure, change the variable type from bool to int.
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Link: https://lore.kernel.org/r/20240719110059.797546-7-xukuohai@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Xu Kuohai [Fri, 19 Jul 2024 11:00:54 +0000 (19:00 +0800)]
bpf: Fix compare error in function retval_range_within
After checking lsm hook return range in verifier, the test case
"test_progs -t test_lsm" failed, and the failure log says:
libbpf: prog 'test_int_hook': BPF program load failed: Invalid argument
libbpf: prog 'test_int_hook': -- BEGIN PROG LOAD LOG --
0: R1=ctx() R10=fp0
; int BPF_PROG(test_int_hook, struct vm_area_struct *vma, @ lsm.c:89
0: (79) r0 = *(u64 *)(r1 +24) ; R0_w=scalar(smin=smin32=-4095,smax=smax32=0) R1=ctx()
[...]
24: (b4) w0 = -1 ; R0_w=0xffffffff
; int BPF_PROG(test_int_hook, struct vm_area_struct *vma, @ lsm.c:89
25: (95) exit
At program exit the register R0 has smin=
4294967295 smax=
4294967295 should have been in [-4095, 0]
It can be seen that instruction "w0 = -1" zero extended -1 to 64-bit
register r0, setting both smin and smax values of r0 to
4294967295.
This resulted in a false reject when r0 was checked with range [-4095, 0].
Given bpf lsm does not return 64-bit values, this patch fixes it by changing
the compare between r0 and return range from 64-bit operation to 32-bit
operation for bpf lsm.
Fixes:
8fa4ecd49b81 ("bpf: enforce exact retval range on subprog/callback exit")
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Link: https://lore.kernel.org/r/20240719110059.797546-5-xukuohai@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Xu Kuohai [Fri, 19 Jul 2024 11:00:53 +0000 (19:00 +0800)]
bpf: Prevent tail call between progs attached to different hooks
bpf progs can be attached to kernel functions, and the attached functions
can take different parameters or return different return values. If
prog attached to one kernel function tail calls prog attached to another
kernel function, the ctx access or return value verification could be
bypassed.
For example, if prog1 is attached to func1 which takes only 1 parameter
and prog2 is attached to func2 which takes two parameters. Since verifier
assumes the bpf ctx passed to prog2 is constructed based on func2's
prototype, verifier allows prog2 to access the second parameter from
the bpf ctx passed to it. The problem is that verifier does not prevent
prog1 from passing its bpf ctx to prog2 via tail call. In this case,
the bpf ctx passed to prog2 is constructed from func1 instead of func2,
that is, the assumption for ctx access verification is bypassed.
Another example, if BPF LSM prog1 is attached to hook file_alloc_security,
and BPF LSM prog2 is attached to hook bpf_lsm_audit_rule_known. Verifier
knows the return value rules for these two hooks, e.g. it is legal for
bpf_lsm_audit_rule_known to return positive number 1, and it is illegal
for file_alloc_security to return positive number. So verifier allows
prog2 to return positive number 1, but does not allow prog1 to return
positive number. The problem is that verifier does not prevent prog1
from calling prog2 via tail call. In this case, prog2's return value 1
will be used as the return value for prog1's hook file_alloc_security.
That is, the return value rule is bypassed.
This patch adds restriction for tail call to prevent such bypasses.
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Link: https://lore.kernel.org/r/20240719110059.797546-4-xukuohai@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Xu Kuohai [Fri, 19 Jul 2024 11:00:52 +0000 (19:00 +0800)]
bpf, lsm: Add check for BPF LSM return value
A bpf prog returning a positive number attached to file_alloc_security
hook makes kernel panic.
This happens because file system can not filter out the positive number
returned by the LSM prog using IS_ERR, and misinterprets this positive
number as a file pointer.
Given that hook file_alloc_security never returned positive number
before the introduction of BPF LSM, and other BPF LSM hooks may
encounter similar issues, this patch adds LSM return value check
in verifier, to ensure no unexpected value is returned.
Fixes:
520b7aa00d8c ("bpf: lsm: Initialize the BPF LSM hooks")
Reported-by: Xin Liu <liuxin350@huawei.com>
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240719110059.797546-3-xukuohai@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Xu Kuohai [Fri, 19 Jul 2024 11:00:51 +0000 (19:00 +0800)]
bpf, lsm: Add disabled BPF LSM hook list
Add a disabled hooks list for BPF LSM. progs being attached to the
listed hooks will be rejected by the verifier.
Suggested-by: KP Singh <kpsingh@kernel.org>
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Link: https://lore.kernel.org/r/20240719110059.797546-2-xukuohai@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Alexei Starovoitov [Mon, 22 Jul 2024 19:21:22 +0000 (12:21 -0700)]
Merge branch 'bpf-retire-the-unsupported_ops-usage-in-struct_ops'
Martin KaFai Lau says:
====================
bpf: Retire the unsupported_ops usage in struct_ops
From: Martin KaFai Lau <martin.lau@kernel.org>
This series retires the unsupported_ops usage and depends on the
null-ness check on the cfi_stubs instead.
Please see individual patches for details.
v2:
- Fixed a gcc compiler warning on Patch 1.
====================
Link: https://lore.kernel.org/r/20240722183049.2254692-1-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Martin KaFai Lau [Mon, 22 Jul 2024 18:30:47 +0000 (11:30 -0700)]
selftests/bpf: Ensure the unsupported struct_ops prog cannot be loaded
There is an existing "bpf_tcp_ca/unsupp_cong_op" test to ensure
the unsupported tcp-cc "get_info" struct_ops prog cannot be loaded.
This patch adds a new test in the bpf_testmod such that the
unsupported ops test does not depend on other kernel subsystem
where its supporting ops may be changed in the future.
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20240722183049.2254692-4-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Martin KaFai Lau [Mon, 22 Jul 2024 18:30:46 +0000 (11:30 -0700)]
selftests/bpf: Fix the missing tramp_1 to tramp_40 ops in cfi_stubs
The tramp_1 to tramp_40 ops is not set in the cfi_stubs in the
bpf_testmod_ops. It fails the struct_ops_multi_pages test after
retiring the unsupported_ops in the earlier patch.
This patch initializes them in a loop during the bpf_testmod_init().
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20240722183049.2254692-3-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Martin KaFai Lau [Mon, 22 Jul 2024 18:30:45 +0000 (11:30 -0700)]
bpf: Check unsupported ops from the bpf_struct_ops's cfi_stubs
The bpf_tcp_ca struct_ops currently uses a "u32 unsupported_ops[]"
array to track which ops is not supported.
After cfi_stubs had been added, the function pointer in cfi_stubs is
also NULL for the unsupported ops. Thus, the "u32 unsupported_ops[]"
becomes redundant. This observation was originally brought up in the
bpf/cfi discussion:
https://lore.kernel.org/bpf/CAADnVQJoEkdjyCEJRPASjBw1QGsKYrF33QdMGc1RZa9b88bAEA@mail.gmail.com/
The recent bpf qdisc patch (https://lore.kernel.org/bpf/
20240714175130.
4051012-6-amery.hung@bytedance.com/)
also needs to specify quite many unsupported ops. It is a good time
to clean it up.
This patch removes the need of "u32 unsupported_ops[]" and tests for null-ness
in the cfi_stubs instead.
Testing the cfi_stubs is done in a new function bpf_struct_ops_supported().
The verifier will call bpf_struct_ops_supported() when loading the
struct_ops program. The ".check_member" is removed from the bpf_tcp_ca
in this patch. ".check_member" could still be useful for other subsytems
to enforce other restrictions (e.g. sched_ext checks for prog->sleepable).
To keep the same error return, ENOTSUPP is used.
Cc: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20240722183049.2254692-2-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tao Chen [Sun, 21 Jul 2024 14:42:52 +0000 (22:42 +0800)]
bpftool: Add document for net attach/detach on tcx subcommand
This commit adds sample output for net attach/detach on
tcx subcommand.
Signed-off-by: Tao Chen <chen.dylane@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20240721144252.96264-1-chen.dylane@gmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tao Chen [Sun, 21 Jul 2024 14:42:38 +0000 (22:42 +0800)]
bpftool: Add bash-completion for tcx subcommand
This commit adds bash-completion for attaching tcx program on interface.
Signed-off-by: Tao Chen <chen.dylane@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20240721144238.96246-1-chen.dylane@gmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tao Chen [Sun, 21 Jul 2024 14:42:21 +0000 (22:42 +0800)]
bpftool: Add net attach/detach command to tcx prog
Now, attach/detach tcx prog supported in libbpf, so we can add new
command 'bpftool attach/detach tcx' to attach tcx prog with bpftool
for user.
# bpftool prog load tc_prog.bpf.o /sys/fs/bpf/tc_prog
# bpftool prog show
...
192: sched_cls name tc_prog tag
187aeb611ad00cfc gpl
loaded_at 2024-07-11T15:58:16+0800 uid 0
xlated 152B jited 97B memlock 4096B map_ids 100,99,97
btf_id 260
# bpftool net attach tcx_ingress name tc_prog dev lo
# bpftool net
...
tc:
lo(1) tcx/ingress tc_prog prog_id 29
# bpftool net detach tcx_ingress dev lo
# bpftool net
...
tc:
# bpftool net attach tcx_ingress name tc_prog dev lo
# bpftool net
tc:
lo(1) tcx/ingress tc_prog prog_id 29
Test environment: ubuntu_22_04, 6.7.0-060700-generic
Signed-off-by: Tao Chen <chen.dylane@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20240721144221.96228-1-chen.dylane@gmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tao Chen [Sun, 21 Jul 2024 14:33:50 +0000 (22:33 +0800)]
bpftool: Refactor xdp attach/detach type judgment
This commit no logical changed, just increases code readability and
facilitates TCX prog expansion, which will be implemented in the next
patch.
Signed-off-by: Tao Chen <chen.dylane@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20240721143353.95980-2-chen.dylane@gmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Alexei Starovoitov [Sat, 20 Jul 2024 02:47:02 +0000 (19:47 -0700)]
Merge branch 'bpf-fix-tailcall-hierarchy'
Leon Hwang says:
====================
bpf: Fix tailcall hierarchy
This patchset fixes a tailcall hierarchy issue.
The issue is confirmed in the discussions of
"bpf, x64: Fix tailcall infinite loop" [0].
The issue has been resolved on both x86_64 and arm64 [1].
I provide a long commit message in the "bpf, x64: Fix tailcall hierarchy"
patch to describe how the issue happens and how this patchset resolves the
issue in details.
How does this patchset resolve the issue?
In short, it stores tail_call_cnt on the stack of main prog, and propagates
tail_call_cnt_ptr to its subprogs.
First, at the prologue of main prog, it initializes tail_call_cnt and
prepares tail_call_cnt_ptr. And at the prologue of subprog, it reuses
the tail_call_cnt_ptr from caller.
Then, when a tailcall happens, it increments tail_call_cnt by its pointer.
v5 -> v6:
* Address comments from Eduard:
* Add JITed dumping along annotating comments
* Rewrite two selftests with RUN_TESTS macro.
v4 -> v5:
* Solution changes from tailcall run ctx to tail_call_cnt and its pointer.
It's because v4 solution is unable to handle the case that there is no
tailcall in subprog but there is tailcall in EXT prog which attaches to
the subprog.
v3 -> v4:
* Solution changes from per-task tail_call_cnt to tailcall run ctx.
As for per-cpu/per-task solution, there is a case it is unable to handle [2].
v2 -> v3:
* Solution changes from percpu tail_call_cnt to tail_call_cnt at task_struct.
v1 -> v2:
* Solution changes from extra run-time call insn to percpu tail_call_cnt.
* Address comments from Alexei:
* Use percpu tail_call_cnt.
* Use asm to make sure no callee saved registers are touched.
RFC v2 -> v1:
* Solution changes from propagating tail_call_cnt with its pointer to extra
run-time call insn.
* Address comments from Maciej:
* Replace all memcpy(prog, x86_nops[5], X86_PATCH_SIZE) with
emit_nops(&prog, X86_PATCH_SIZE)
RFC v1 -> RFC v2:
* Address comments from Stanislav:
* Separate moving emit_nops() as first patch.
Links:
[0] https://lore.kernel.org/bpf/
6203dd01-789d-f02c-5293-
def4c1b18aef@gmail.com/
[1] https://github.com/kernel-patches/bpf/pull/7350/checks
[2] https://lore.kernel.org/bpf/CAADnVQK1qF+uBjwom2s2W-yEmgd_3rGi5Nr+KiV3cW0T+UPPfA@mail.gmail.com/
====================
Link: https://lore.kernel.org/r/20240714123902.32305-1-hffilwlqm@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Leon Hwang [Sun, 14 Jul 2024 12:39:02 +0000 (20:39 +0800)]
selftests/bpf: Add testcases for tailcall hierarchy fixing
Add some test cases to confirm the tailcall hierarchy issue has been fixed.
On x64, the selftests result is:
cd tools/testing/selftests/bpf && ./test_progs -t tailcalls
327/18 tailcalls/tailcall_bpf2bpf_hierarchy_1:OK
327/19 tailcalls/tailcall_bpf2bpf_hierarchy_fentry:OK
327/20 tailcalls/tailcall_bpf2bpf_hierarchy_fexit:OK
327/21 tailcalls/tailcall_bpf2bpf_hierarchy_fentry_fexit:OK
327/22 tailcalls/tailcall_bpf2bpf_hierarchy_fentry_entry:OK
327/23 tailcalls/tailcall_bpf2bpf_hierarchy_2:OK
327/24 tailcalls/tailcall_bpf2bpf_hierarchy_3:OK
327 tailcalls:OK
Summary: 1/24 PASSED, 0 SKIPPED, 0 FAILED
On arm64, the selftests result is:
cd tools/testing/selftests/bpf && ./test_progs -t tailcalls
327/18 tailcalls/tailcall_bpf2bpf_hierarchy_1:OK
327/19 tailcalls/tailcall_bpf2bpf_hierarchy_fentry:OK
327/20 tailcalls/tailcall_bpf2bpf_hierarchy_fexit:OK
327/21 tailcalls/tailcall_bpf2bpf_hierarchy_fentry_fexit:OK
327/22 tailcalls/tailcall_bpf2bpf_hierarchy_fentry_entry:OK
327/23 tailcalls/tailcall_bpf2bpf_hierarchy_2:OK
327/24 tailcalls/tailcall_bpf2bpf_hierarchy_3:OK
327 tailcalls:OK
Summary: 1/24 PASSED, 0 SKIPPED, 0 FAILED
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Leon Hwang <hffilwlqm@gmail.com>
Link: https://lore.kernel.org/r/20240714123902.32305-4-hffilwlqm@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Leon Hwang [Sun, 14 Jul 2024 12:39:01 +0000 (20:39 +0800)]
bpf, arm64: Fix tailcall hierarchy
This patch fixes a tailcall issue caused by abusing the tailcall in
bpf2bpf feature on arm64 like the way of "bpf, x64: Fix tailcall
hierarchy".
On arm64, when a tail call happens, it uses tail_call_cnt_ptr to
increment tail_call_cnt, too.
At the prologue of main prog, it has to initialize tail_call_cnt and
prepare tail_call_cnt_ptr.
At the prologue of subprog, it pushes x26 register twice, and does not
initialize tail_call_cnt.
At the epilogue, it pops x26 twice, no matter whether it is main prog or
subprog.
Fixes:
d4609a5d8c70 ("bpf, arm64: Keep tail call count across bpf2bpf calls")
Acked-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Leon Hwang <hffilwlqm@gmail.com>
Link: https://lore.kernel.org/r/20240714123902.32305-3-hffilwlqm@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Leon Hwang [Sun, 14 Jul 2024 12:39:00 +0000 (20:39 +0800)]
bpf, x64: Fix tailcall hierarchy
This patch fixes a tailcall issue caused by abusing the tailcall in
bpf2bpf feature.
As we know, tail_call_cnt propagates by rax from caller to callee when
to call subprog in tailcall context. But, like the following example,
MAX_TAIL_CALL_CNT won't work because of missing tail_call_cnt
back-propagation from callee to caller.
\#include <linux/bpf.h>
\#include <bpf/bpf_helpers.h>
\#include "bpf_legacy.h"
struct {
__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
__uint(max_entries, 1);
__uint(key_size, sizeof(__u32));
__uint(value_size, sizeof(__u32));
} jmp_table SEC(".maps");
int count = 0;
static __noinline
int subprog_tail1(struct __sk_buff *skb)
{
bpf_tail_call_static(skb, &jmp_table, 0);
return 0;
}
static __noinline
int subprog_tail2(struct __sk_buff *skb)
{
bpf_tail_call_static(skb, &jmp_table, 0);
return 0;
}
SEC("tc")
int entry(struct __sk_buff *skb)
{
volatile int ret = 1;
count++;
subprog_tail1(skb);
subprog_tail2(skb);
return ret;
}
char __license[] SEC("license") = "GPL";
At run time, the tail_call_cnt in entry() will be propagated to
subprog_tail1() and subprog_tail2(). But, when the tail_call_cnt in
subprog_tail1() updates when bpf_tail_call_static(), the tail_call_cnt
in entry() won't be updated at the same time. As a result, in entry(),
when tail_call_cnt in entry() is less than MAX_TAIL_CALL_CNT and
subprog_tail1() returns because of MAX_TAIL_CALL_CNT limit,
bpf_tail_call_static() in suprog_tail2() is able to run because the
tail_call_cnt in subprog_tail2() propagated from entry() is less than
MAX_TAIL_CALL_CNT.
So, how many tailcalls are there for this case if no error happens?
From top-down view, does it look like hierarchy layer and layer?
With this view, there will be 2+4+8+...+2^33 = 2^34 - 2 = 17,179,869,182
tailcalls for this case.
How about there are N subprog_tail() in entry()? There will be almost
N^34 tailcalls.
Then, in this patch, it resolves this case on x86_64.
In stead of propagating tail_call_cnt from caller to callee, it
propagates its pointer, tail_call_cnt_ptr, tcc_ptr for short.
However, where does it store tail_call_cnt?
It stores tail_call_cnt on the stack of main prog. When tail call
happens in subprog, it increments tail_call_cnt by tcc_ptr.
Meanwhile, it stores tail_call_cnt_ptr on the stack of main prog, too.
And, before jump to tail callee, it has to pop tail_call_cnt and
tail_call_cnt_ptr.
Then, at the prologue of subprog, it must not make rax as
tail_call_cnt_ptr again. It has to reuse tail_call_cnt_ptr from caller.
As a result, at run time, it has to recognize rax is tail_call_cnt or
tail_call_cnt_ptr at prologue by:
1. rax is tail_call_cnt if rax is <= MAX_TAIL_CALL_CNT.
2. rax is tail_call_cnt_ptr if rax is > MAX_TAIL_CALL_CNT, because a
pointer won't be <= MAX_TAIL_CALL_CNT.
Here's an example to dump JITed.
struct {
__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
__uint(max_entries, 1);
__uint(key_size, sizeof(__u32));
__uint(value_size, sizeof(__u32));
} jmp_table SEC(".maps");
int count = 0;
static __noinline
int subprog_tail(struct __sk_buff *skb)
{
bpf_tail_call_static(skb, &jmp_table, 0);
return 0;
}
SEC("tc")
int entry(struct __sk_buff *skb)
{
int ret = 1;
count++;
subprog_tail(skb);
subprog_tail(skb);
return ret;
}
When bpftool p d j id 42:
int entry(struct __sk_buff * skb):
bpf_prog_0c0f4c2413ef19b1_entry:
; int entry(struct __sk_buff *skb)
0: endbr64
4: nopl (%rax,%rax)
9: xorq %rax, %rax ;; rax = 0 (tail_call_cnt)
c: pushq %rbp
d: movq %rsp, %rbp
10: endbr64
14: cmpq $33, %rax ;; if rax > 33, rax = tcc_ptr
18: ja 0x20 ;; if rax > 33 goto 0x20 ---+
1a: pushq %rax ;; [rbp - 8] = rax = 0 |
1b: movq %rsp, %rax ;; rax = rbp - 8 |
1e: jmp 0x21 ;; ---------+ |
20: pushq %rax ;; <--------|---------------+
21: pushq %rax ;; <--------+ [rbp - 16] = rax
22: pushq %rbx ;; callee saved
23: movq %rdi, %rbx ;; rbx = skb (callee saved)
; count++;
26: movabsq $-
82417199407104, %rdi
30: movl (%rdi), %esi
33: addl $1, %esi
36: movl %esi, (%rdi)
; subprog_tail(skb);
39: movq %rbx, %rdi ;; rdi = skb
3c: movq -16(%rbp), %rax ;; rax = tcc_ptr
43: callq 0x80 ;; call subprog_tail()
; subprog_tail(skb);
48: movq %rbx, %rdi ;; rdi = skb
4b: movq -16(%rbp), %rax ;; rax = tcc_ptr
52: callq 0x80 ;; call subprog_tail()
; return ret;
57: movl $1, %eax
5c: popq %rbx
5d: leave
5e: retq
int subprog_tail(struct __sk_buff * skb):
bpf_prog_3a140cef239a4b4f_subprog_tail:
; int subprog_tail(struct __sk_buff *skb)
0: endbr64
4: nopl (%rax,%rax)
9: nopl (%rax) ;; do not touch tail_call_cnt
c: pushq %rbp
d: movq %rsp, %rbp
10: endbr64
14: pushq %rax ;; [rbp - 8] = rax (tcc_ptr)
15: pushq %rax ;; [rbp - 16] = rax (tcc_ptr)
16: pushq %rbx ;; callee saved
17: pushq %r13 ;; callee saved
19: movq %rdi, %rbx ;; rbx = skb
; asm volatile("r1 = %[ctx]\n\t"
1c: movabsq $-
105487587488768, %r13 ;; r13 = jmp_table
26: movq %rbx, %rdi ;; 1st arg, skb
29: movq %r13, %rsi ;; 2nd arg, jmp_table
2c: xorl %edx, %edx ;; 3rd arg, index = 0
2e: movq -16(%rbp), %rax ;; rax = [rbp - 16] (tcc_ptr)
35: cmpq $33, (%rax)
39: jae 0x4e ;; if *tcc_ptr >= 33 goto 0x4e --------+
3b: jmp 0x4e ;; jmp bypass, toggled by poking |
40: addq $1, (%rax) ;; (*tcc_ptr)++ |
44: popq %r13 ;; callee saved |
46: popq %rbx ;; callee saved |
47: popq %rax ;; undo rbp-16 push |
48: popq %rax ;; undo rbp-8 push |
49: nopl (%rax,%rax) ;; tail call target, toggled by poking |
; return 0; ;; |
4e: popq %r13 ;; restore callee saved <--------------+
50: popq %rbx ;; restore callee saved
51: leave
52: retq
Furthermore, when trampoline is the caller of bpf prog, which is
tail_call_reachable, it is required to propagate rax through trampoline.
Fixes:
ebf7d1f508a7 ("bpf, x64: rework pro/epilogue and tailcall handling in JIT")
Fixes:
e411901c0b77 ("bpf: allow for tailcalls in BPF subprograms for x64 JIT")
Reviewed-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Leon Hwang <hffilwlqm@gmail.com>
Link: https://lore.kernel.org/r/20240714123902.32305-2-hffilwlqm@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Andrii Nakryiko [Fri, 19 Jul 2024 23:17:45 +0000 (16:17 -0700)]
Merge branch 'bpf-track-find_equal_scalars-history-on-per-instruction-level'
Eduard Zingerman says:
====================
bpf: track find_equal_scalars history on per-instruction level
This is a fix for precision tracking bug reported in [0].
It supersedes my previous attempt to fix similar issue in commit [1].
Here is a minimized test case from [0]:
0: call bpf_get_prandom_u32;
1: r7 = r0;
2: r8 = r0;
3: call bpf_get_prandom_u32;
4: if r0 > 1 goto +0;
/* --- checkpoint #1: r7.id=1, r8.id=1 --- */
5: if r8 >= r0 goto 9f;
6: r8 += r8;
/* --- checkpoint #2: r7.id=1, r8.id=0 --- */
7: if r7 == 0 goto 9f;
8: r0 /= 0;
/* --- checkpoint #3 --- */
9: r0 = 42;
10: exit;
W/o this fix verifier incorrectly assumes that instruction at label
(8) is unreachable. The issue is caused by failure to infer
precision mark for r0 at checkpoint #1:
- first verification path is:
- (0-4): r0 range [0,1];
- (5): r8 range [0,0], propagated to r7;
- (6): r8.id is reset;
- (7): jump is predicted to happen;
- (9-10): safe exit.
- when jump at (7) is predicted mark_chain_precision() for r7 is
called and backtrack_insn() proceeds as follows:
- at (7) r7 is marked as precise;
- at (5) r8 is not currently tracked and thus r0 is not marked;
- at (4-5) boundary logic from [1] is triggered and r7,r8 are marked
as precise;
- => r0 precision mark is missed.
- when second branch of (4) is considered, verifier prunes the state
because r0 is not marked as precise in the visited state.
Basically, backtracking logic fails to notice that at (5)
range information is gained for both r7 and r8, and thus both
r8 and r0 have to be marked as precise.
This happens because [1] can only account for such range
transfers at parent/child state boundaries.
The solution suggested by Andrii Nakryiko in [0] is to use jump
history to remember which registers gained range as a result of
find_equal_scalars() [renamed to sync_linked_regs()] and use
this information in backtrack_insn().
Which is what this patch-set does.
The patch-set uses u64 value as a vector of 10-bit values that
identify registers gaining range in find_equal_scalars().
This amounts to maximum of 6 possible values.
To check if such capacity is sufficient I've instrumented kernel
to track a histogram for maximal amount of registers that gain range
in find_equal_scalars per program verification [2].
Measurements done for verifier selftests and Cilium bpf object files
from [3] show that number of such registers is *always* <= 4 and
in 98% of cases it is <= 2.
When tested on a subset of selftests identified by
selftests/bpf/veristat.cfg and Cilium bpf object files from [3]
this patch-set has minimal verification performance impact:
File Program Insns (DIFF) States (DIFF)
------------------------ ------------------------ -------------- -------------
bpf_host.o tail_handle_nat_fwd_ipv4 -75 (-0.61%) -3 (-0.39%)
pyperf600_nounroll.bpf.o on_event +1673 (+0.33%) +3 (+0.01%)
[0] https://lore.kernel.org/bpf/CAEf4BzZ0xidVCqB47XnkXcNhkPWF6_nTV7yt+_Lf0kcFEut2Mg@mail.gmail.com/
[1] commit
904e6ddf4133 ("bpf: Use scalar ids in mark_chain_precision()")
[2] https://github.com/eddyz87/bpf/tree/find-equal-scalars-in-jump-history-with-stats
[3] https://github.com/anakryiko/cilium
Changes:
- v2 -> v3:
A number of stylistic changes suggested by Andrii:
- renamings:
- struct reg_or_spill -> linked_reg;
- find_equal_scalars() -> collect_linked_regs;
- copy_known_reg() -> sync_linked_regs;
- collect_linked_regs() now returns linked regs set of
size 2 or larger;
- dropped usage of bit fields in struct linked_reg;
- added a patch changing references to find_equal_scalars() in
selftests comments.
- v1 -> v2:
- patch "bpf: replace env->cur_hist_ent with a getter function" is
dropped (Andrii);
- added structure linked_regs and helper functions to [de]serialize
u64 value as such structure (Andrii);
- bt_set_equal_scalars() renamed to bt_sync_linked_regs(), moved to
start and end of backtrack_insn() in order to untie linked
register logic from conditional jumps backtracking.
Andrii requested a more radical change of moving linked registers
processing to bt_set_xxx() functions, I did an experiment in this
direction:
https://github.com/eddyz87/bpf/tree/find-equal-scalars-in-jump-history--linked-regs-in-bt-set-reg
the end result of the experiment seems much uglier than version
presented in v2.
Revisions:
- v1: https://lore.kernel.org/bpf/
20240222005005.31784-1-eddyz87@gmail.com/
- v2: https://lore.kernel.org/bpf/
20240705205851.
2635794-1-eddyz87@gmail.com/
====================
Link: https://lore.kernel.org/r/20240718202357.1746514-1-eddyz87@gmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Eduard Zingerman [Thu, 18 Jul 2024 20:23:56 +0000 (13:23 -0700)]
selftests/bpf: Update comments find_equal_scalars->sync_linked_regs
find_equal_scalars() is renamed to sync_linked_regs(),
this commit updates existing references in the selftests comments.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240718202357.1746514-5-eddyz87@gmail.com
Eduard Zingerman [Thu, 18 Jul 2024 20:23:55 +0000 (13:23 -0700)]
selftests/bpf: Tests for per-insn sync_linked_regs() precision tracking
Add a few test cases to verify precision tracking for scalars gaining
range because of sync_linked_regs():
- check what happens when more than 6 registers might gain range in
sync_linked_regs();
- check if precision is propagated correctly when operand of
conditional jump gained range in sync_linked_regs() and one of
linked registers is marked precise;
- check if precision is propagated correctly when operand of
conditional jump gained range in sync_linked_regs() and a
other-linked operand of the conditional jump is marked precise;
- add a minimized reproducer for precision tracking bug reported in [0];
- Check that mark_chain_precision() for one of the conditional jump
operands does not trigger equal scalars precision propagation.
[0] https://lore.kernel.org/bpf/CAEf4BzZ0xidVCqB47XnkXcNhkPWF6_nTV7yt+_Lf0kcFEut2Mg@mail.gmail.com/
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240718202357.1746514-4-eddyz87@gmail.com
Eduard Zingerman [Thu, 18 Jul 2024 20:23:54 +0000 (13:23 -0700)]
bpf: Remove mark_precise_scalar_ids()
Function mark_precise_scalar_ids() is superseded by
bt_sync_linked_regs() and equal scalars tracking in jump history.
mark_precise_scalar_ids() propagates precision over registers sharing
same ID on parent/child state boundaries, while jump history records
allow bt_sync_linked_regs() to propagate same information with
instruction level granularity, which is strictly more precise.
This commit removes mark_precise_scalar_ids() and updates test cases
in progs/verifier_scalar_ids to reflect new verifier behavior.
The tests are updated in the following manner:
- mark_precise_scalar_ids() propagated precision regardless of
presence of conditional jumps, while new jump history based logic
only kicks in when conditional jumps are present.
Hence test cases are augmented with conditional jumps to still
trigger precision propagation.
- As equal scalars tracking no longer relies on parent/child state
boundaries some test cases are no longer interesting,
such test cases are removed, namely:
- precision_same_state and precision_cross_state are superseded by
linked_regs_bpf_k;
- precision_same_state_broken_link and equal_scalars_broken_link
are superseded by linked_regs_broken_link.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240718202357.1746514-3-eddyz87@gmail.com
Eduard Zingerman [Thu, 18 Jul 2024 20:23:53 +0000 (13:23 -0700)]
bpf: Track equal scalars history on per-instruction level
Use bpf_verifier_state->jmp_history to track which registers were
updated by find_equal_scalars() (renamed to collect_linked_regs())
when conditional jump was verified. Use recorded information in
backtrack_insn() to propagate precision.
E.g. for the following program:
while verifying instructions
1: r1 = r0 |
2: if r1 < 8 goto ... | push r0,r1 as linked registers in jmp_history
3: if r0 > 16 goto ... | push r0,r1 as linked registers in jmp_history
4: r2 = r10 |
5: r2 += r0 v mark_chain_precision(r0)
while doing mark_chain_precision(r0)
5: r2 += r0 | mark r0 precise
4: r2 = r10 |
3: if r0 > 16 goto ... | mark r0,r1 as precise
2: if r1 < 8 goto ... | mark r0,r1 as precise
1: r1 = r0 v
Technically, do this as follows:
- Use 10 bits to identify each register that gains range because of
sync_linked_regs():
- 3 bits for frame number;
- 6 bits for register or stack slot number;
- 1 bit to indicate if register is spilled.
- Use u64 as a vector of 6 such records + 4 bits for vector length.
- Augment struct bpf_jmp_history_entry with a field 'linked_regs'
representing such vector.
- When doing check_cond_jmp_op() remember up to 6 registers that
gain range because of sync_linked_regs() in such a vector.
- Don't propagate range information and reset IDs for registers that
don't fit in 6-value vector.
- Push a pair {instruction index, linked registers vector}
to bpf_verifier_state->jmp_history.
- When doing backtrack_insn() check if any of recorded linked
registers is currently marked precise, if so mark all linked
registers as precise.
This also requires fixes for two test_verifier tests:
- precise: test 1
- precise: test 2
Both tests contain the following instruction sequence:
19: (bf) r2 = r9 ; R2=scalar(id=3) R9=scalar(id=3)
20: (a5) if r2 < 0x8 goto pc+1 ; R2=scalar(id=3,umin=8)
21: (95) exit
22: (07) r2 += 1 ; R2_w=scalar(id=3+1,...)
23: (bf) r1 = r10 ; R1_w=fp0 R10=fp0
24: (07) r1 += -8 ; R1_w=fp-8
25: (b7) r3 = 0 ; R3_w=0
26: (85) call bpf_probe_read_kernel#113
The call to bpf_probe_read_kernel() at (26) forces r2 to be precise.
Previously, this forced all registers with same id to become precise
immediately when mark_chain_precision() is called.
After this change, the precision is propagated to registers sharing
same id only when 'if' instruction is backtracked.
Hence verification log for both tests is changed:
regs=r2,r9 -> regs=r2 for instructions 25..20.
Fixes:
904e6ddf4133 ("bpf: Use scalar ids in mark_chain_precision()")
Reported-by: Hao Sun <sunhao.th@gmail.com>
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240718202357.1746514-2-eddyz87@gmail.com
Closes: https://lore.kernel.org/bpf/CAEf4BzZ0xidVCqB47XnkXcNhkPWF6_nTV7yt+_Lf0kcFEut2Mg@mail.gmail.com/
Ihor Solodrai [Thu, 18 Jul 2024 22:57:43 +0000 (22:57 +0000)]
selftests/bpf: Use auto-dependencies for test objects
Make use of -M compiler options when building .test.o objects to
generate .d files and avoid re-building all tests every time.
Previously, if a single test bpf program under selftests/bpf/progs/*.c
has changed, make would rebuild all the *.bpf.o, *.skel.h and *.test.o
objects, which is a lot of unnecessary work.
A typical dependency chain is:
progs/x.c -> x.bpf.o -> x.skel.h -> x.test.o -> trunner_binary
However for many tests it's not a 1:1 mapping by name, and so far
%.test.o have been simply dependent on all %.skel.h files, and
%.skel.h files on all %.bpf.o objects.
Avoid full rebuilds by instructing the compiler (via -MMD) to
produce *.d files with real dependencies, and appropriately including
them. Exploit make feature that rebuilds included makefiles if they
were changed by setting %.test.d as prerequisite for %.test.o files.
A couple of examples of compilation time speedup (after the first
clean build):
$ touch progs/verifier_and.c && time make -j8
Before: real 0m16.651s
After: real 0m2.245s
$ touch progs/read_vsyscall.c && time make -j8
Before: real 0m15.743s
After: real 0m1.575s
A drawback of this change is that now there is an overhead due to make
processing lots of .d files, which potentially may slow down unrelated
targets. However a time to make all from scratch hasn't changed
significantly:
$ make clean && time make -j8
Before: real 1m31.148s
After: real 1m30.309s
Suggested-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Ihor Solodrai <ihor.solodrai@pm.me>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/VJihUTnvtwEgv_mOnpfy7EgD9D2MPNoHO-MlANeLIzLJPGhDeyOuGKIYyKgk0O6KPjfM-MuhtvPwZcngN8WFqbTnTRyCSMc2aMZ1ODm1T_g=@pm.me
Markus Elfring [Mon, 15 Jul 2024 09:12:30 +0000 (11:12 +0200)]
bpf: Simplify character output in seq_print_delegate_opts()
Single characters should be put into a sequence.
Thus use the corresponding function “seq_putc” for two selected calls.
This issue was transformed by using the Coccinelle software.
Suggested-by: Christophe Jaillet <christophe.jaillet@wanadoo.fr>
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/abde0992-3d71-44d2-ab27-75b382933a22@web.de
Markus Elfring [Sun, 14 Jul 2024 14:15:34 +0000 (16:15 +0200)]
bpf: Replace 8 seq_puts() calls by seq_putc() calls
Single line breaks should occasionally be put into a sequence.
Thus use the corresponding function “seq_putc”.
This issue was transformed by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/e26b7df9-cd63-491f-85e8-8cabe60a85e5@web.de
Martin KaFai Lau [Thu, 18 Jul 2024 19:07:19 +0000 (12:07 -0700)]
Merge branch 'use network helpers, part 9'
Geliang Tang says:
====================
v3:
- patch 2:
- clear errno before connect_to_fd_opts.
- print err logs in run_test.
- set err to -1 when fd >= 0.
- patch 3:
- drop "int err".
v2:
- update patch 2 as Martin suggested.
This is the 9th part of series "use network helpers" all BPF selftests
wide.
Patches 1-2 update network helpers interfaces suggested by Martin.
Patch 3 adds a new helper connect_to_addr_str() as Martin suggested
instead of adding connect_fd_to_addr_str().
Patch 4 uses this newly added helper in make_client().
Patch 5 uses make_client() in sk_lookup and drop make_socket().
====================
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Geliang Tang [Thu, 18 Jul 2024 06:22:31 +0000 (14:22 +0800)]
selftests/bpf: Add connect_to_addr_str helper
Similar to connect_to_addr() helper for connecting to a server with the
given sockaddr_storage type address, this patch adds a new helper named
connect_to_addr_str() for connecting to a server with the given string
type address "addr_str", together with its "family" and "port" as other
parameters of connect_to_addr_str().
In connect_to_addr_str(), the parameters "family", "addr_str" and "port"
are used to create a sockaddr_storage type address "addr" by invoking
make_sockaddr(). Then pass this "addr" together with "addrlen", "type"
and "opts" to connect_to_addr().
Suggested-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Link: https://lore.kernel.org/r/647e82170831558dbde132a7a3d86df660dba2c4.1721282219.git.tanggeliang@kylinos.cn
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Geliang Tang [Thu, 18 Jul 2024 06:22:30 +0000 (14:22 +0800)]
selftests/bpf: Drop must_fail from network_helper_opts
The struct member "must_fail" of network_helper_opts() is only used in
cgroup_v1v2 tests, it makes sense to drop it from network_helper_opts.
Return value (fd) of connect_to_fd_opts() and the expect errno (EPERM)
can be checked in cgroup_v1v2.c directly, no need to check them in
connect_fd_to_addr() in network_helpers.c.
This also makes connect_fd_to_addr() function useless. It can be replaced
by connect().
Suggested-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Link: https://lore.kernel.org/r/3faf336019a9a48e2e8951f4cdebf19e3ac6e441.1721282219.git.tanggeliang@kylinos.cn
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Geliang Tang [Thu, 18 Jul 2024 06:22:29 +0000 (14:22 +0800)]
selftests/bpf: Drop type of connect_to_fd_opts
The "type" parameter of connect_to_fd_opts() is redundant of "server_fd".
Since the "type" can be obtained inside by invoking getsockopt(SO_TYPE),
without passing it in as a parameter.
This patch drops the "type" parameter of connect_to_fd_opts() and updates
its callers.
Suggested-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Link: https://lore.kernel.org/r/50d8ce7ab7ab0c0f4d211fc7cc4ebe3d3f63424c.1721282219.git.tanggeliang@kylinos.cn
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Linus Torvalds [Thu, 25 Jul 2024 20:32:25 +0000 (13:32 -0700)]
Merge tag 'net-6.11-rc1' of git://git./linux/kernel/git/netdev/net
Pull networking fixes from Jakub Kicinski:
"Including fixes from bpf and netfilter.
A lot of networking people were at a conference last week, busy
catching COVID, so relatively short PR.
Current release - regressions:
- tcp: process the 3rd ACK with sk_socket for TFO and MPTCP
Current release - new code bugs:
- l2tp: protect session IDR and tunnel session list with one lock,
make sure the state is coherent to avoid a warning
- eth: bnxt_en: update xdp_rxq_info in queue restart logic
- eth: airoha: fix location of the MBI_RX_AGE_SEL_MASK field
Previous releases - regressions:
- xsk: require XDP_UMEM_TX_METADATA_LEN to actuate tx_metadata_len,
the field reuses previously un-validated pad
Previous releases - always broken:
- tap/tun: drop short frames to prevent crashes later in the stack
- eth: ice: add a per-VF limit on number of FDIR filters
- af_unix: disable MSG_OOB handling for sockets in sockmap/sockhash"
* tag 'net-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (34 commits)
tun: add missing verification for short frame
tap: add missing verification for short frame
mISDN: Fix a use after free in hfcmulti_tx()
gve: Fix an edge case for TSO skb validity check
bnxt_en: update xdp_rxq_info in queue restart logic
tcp: process the 3rd ACK with sk_socket for TFO/MPTCP
selftests/bpf: Add XDP_UMEM_TX_METADATA_LEN to XSK TX metadata test
xsk: Require XDP_UMEM_TX_METADATA_LEN to actuate tx_metadata_len
bpf: Fix a segment issue when downgrading gso_size
net: mediatek: Fix potential NULL pointer dereference in dummy net_device handling
MAINTAINERS: make Breno the netconsole maintainer
MAINTAINERS: Update bonding entry
net: nexthop: Initialize all fields in dumped nexthops
net: stmmac: Correct byte order of perfect_match
selftests: forwarding: skip if kernel not support setting bridge fdb learning limit
tipc: Return non-zero value from tipc_udp_addr2str() on error
netfilter: nft_set_pipapo_avx2: disable softinterrupts
ice: Fix recipe read procedure
ice: Add a per-VF limit on number of FDIR filters
net: bonding: correctly annotate RCU in bond_should_notify_peers()
...
Linus Torvalds [Thu, 25 Jul 2024 20:18:41 +0000 (13:18 -0700)]
Merge tag 'printk-for-6.11-trivial' of git://git./linux/kernel/git/printk/linux
Pull printk updates from Petr Mladek:
- trivial printk changes
The bigger "real" printk work is still being discussed.
* tag 'printk-for-6.11-trivial' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
vsprintf: add missing MODULE_DESCRIPTION() macro
printk: Rename console_replay_all() and update context
Linus Torvalds [Thu, 25 Jul 2024 19:58:36 +0000 (12:58 -0700)]
Merge tag 'constfy-sysctl-6.11-rc1' of git://git./linux/kernel/git/sysctl/sysctl
Pull sysctl constification from Joel Granados:
"Treewide constification of the ctl_table argument of proc_handlers
using a coccinelle script and some manual code formatting fixups.
This is a prerequisite to moving the static ctl_table structs into
read-only data section which will ensure that proc_handler function
pointers cannot be modified"
* tag 'constfy-sysctl-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl:
sysctl: treewide: constify the ctl_table argument of proc_handlers
Linus Torvalds [Thu, 25 Jul 2024 19:55:21 +0000 (12:55 -0700)]
Merge tag 'efi-fixes-for-v6.11-1' of git://git./linux/kernel/git/efi/efi
Pull EFI fixes from Ard Biesheuvel:
- Wipe screen_info after allocating it from the heap - used by arm32
and EFI zboot, other EFI architectures allocate it statically
- Revert to allocating boot_params from the heap on x86 when entering
via the native PE entrypoint, to work around a regression on older
Dell hardware
* tag 'efi-fixes-for-v6.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
x86/efistub: Revert to heap allocated boot_params for PE entrypoint
efi/libstub: Zero initialize heap allocated struct screen_info
Linus Torvalds [Thu, 25 Jul 2024 19:48:42 +0000 (12:48 -0700)]
Merge tag 'kgdb-6.11-rc1' of git://git./linux/kernel/git/danielt/linux
Pull kgdb updates from Daniel Thompson:
"Three small changes this cycle:
- Clean up an architecture abstraction that is no longer needed
because all the architectures have converged.
- Actually use the prompt argument to kdb_position_cursor() instead
of ignoring it (functionally this fix is a nop but that was due to
luck rather than good judgement)
- Fix a -Wformat-security warning"
* tag 'kgdb-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux:
kdb: Get rid of redundant kdb_curr_task()
kdb: Use the passed prompt in kdb_position_cursor()
kdb: address -Wformat-security warnings
Linus Torvalds [Thu, 25 Jul 2024 19:41:53 +0000 (12:41 -0700)]
Merge tag 'mips_6.11_1' of git://git./linux/kernel/git/mips/linux
Pull MIPS updates from Thomas Bogendoerfer:
- Use improved timer sync for Loongson64
- Fix address of GCR_ACCESS register
- Add missing MODULE_DESCRIPTION
* tag 'mips_6.11_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
mips: sibyte: add missing MODULE_DESCRIPTION() macro
MIPS: SMP-CPS: Fix address for GCR_ACCESS register for CM3 and later
MIPS: Loongson64: Switch to SYNC_R4K
Linus Torvalds [Thu, 25 Jul 2024 19:37:42 +0000 (12:37 -0700)]
Merge tag 'parisc-for-6.11-rc1' of git://git./linux/kernel/git/deller/parisc-linux
Pull parisc updates from Helge Deller:
"The gettimeofday() and clock_gettime() syscalls are now available as
vDSO functions, and Dave added a patch which allows to use NVMe cards
in the PCI slots as fast and easy alternative to SCSI discs.
Summary:
- add gettimeofday() and clock_gettime() vDSO functions
- enable PCI_MSI_ARCH_FALLBACKS to allow PCI to PCIe bridge adaptor
with PCIe NVME card to function in parisc machines
- allow users to reduce kernel unaligned runtime warnings
- minor code cleanups"
* tag 'parisc-for-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc: Add support for CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
parisc: Use max() to calculate parisc_tlb_flush_threshold
parisc: Fix warning at drivers/pci/msi/msi.h:121
parisc: Add 64-bit gettimeofday() and clock_gettime() vDSO functions
parisc: Add 32-bit gettimeofday() and clock_gettime() vDSO functions
parisc: Clean up unistd.h file
Linus Torvalds [Thu, 25 Jul 2024 19:33:08 +0000 (12:33 -0700)]
Merge tag 'uml-for-linus-6.11-rc1' of git://git./linux/kernel/git/uml/linux
Pull UML updates from Richard Weinberger:
- Support for preemption
- i386 Rust support
- Huge cleanup by Benjamin Berg
- UBSAN support
- Removal of dead code
* tag 'uml-for-linus-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux: (41 commits)
um: vector: always reset vp->opened
um: vector: remove vp->lock
um: register power-off handler
um: line: always fill *error_out in setup_one_line()
um: remove pcap driver from documentation
um: Enable preemption in UML
um: refactor TLB update handling
um: simplify and consolidate TLB updates
um: remove force_flush_all from fork_handler
um: Do not flush MM in flush_thread
um: Delay flushing syscalls until the thread is restarted
um: remove copy_context_skas0
um: remove LDT support
um: compress memory related stub syscalls while adding them
um: Rework syscall handling
um: Add generic stub_syscall6 function
um: Create signal stack memory assignment in stub_data
um: Remove stub-data.h include from common-offsets.h
um: time-travel: fix signal blocking race/hang
um: time-travel: remove time_exit()
...
Linus Torvalds [Thu, 25 Jul 2024 17:42:22 +0000 (10:42 -0700)]
Merge tag 'driver-core-6.11-rc1' of git://git./linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
"Here is the big set of driver core changes for 6.11-rc1.
Lots of stuff in here, with not a huge diffstat, but apis are evolving
which required lots of files to be touched. Highlights of the changes
in here are:
- platform remove callback api final fixups (Uwe took many releases
to get here, finally!)
- Rust bindings for basic firmware apis and initial driver-core
interactions.
It's not all that useful for a "write a whole driver in rust" type
of thing, but the firmware bindings do help out the phy rust
drivers, and the driver core bindings give a solid base on which
others can start their work.
There is still a long way to go here before we have a multitude of
rust drivers being added, but it's a great first step.
- driver core const api changes.
This reached across all bus types, and there are some fix-ups for
some not-common bus types that linux-next and 0-day testing shook
out.
This work is being done to help make the rust bindings more safe,
as well as the C code, moving toward the end-goal of allowing us to
put driver structures into read-only memory. We aren't there yet,
but are getting closer.
- minor devres cleanups and fixes found by code inspection
- arch_topology minor changes
- other minor driver core cleanups
All of these have been in linux-next for a very long time with no
reported problems"
* tag 'driver-core-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (55 commits)
ARM: sa1100: make match function take a const pointer
sysfs/cpu: Make crash_hotplug attribute world-readable
dio: Have dio_bus_match() callback take a const *
zorro: make match function take a const pointer
driver core: module: make module_[add|remove]_driver take a const *
driver core: make driver_find_device() take a const *
driver core: make driver_[create|remove]_file take a const *
firmware_loader: fix soundness issue in `request_internal`
firmware_loader: annotate doctests as `no_run`
devres: Correct code style for functions that return a pointer type
devres: Initialize an uninitialized struct member
devres: Fix memory leakage caused by driver API devm_free_percpu()
devres: Fix devm_krealloc() wasting memory
driver core: platform: Switch to use kmemdup_array()
driver core: have match() callback in struct bus_type take a const *
MAINTAINERS: add Rust device abstractions to DRIVER CORE
device: rust: improve safety comments
MAINTAINERS: add Danilo as FIRMWARE LOADER maintainer
MAINTAINERS: add Rust FW abstractions to FIRMWARE LOADER
firmware: rust: improve safety comments
...
Linus Torvalds [Thu, 25 Jul 2024 17:18:35 +0000 (10:18 -0700)]
Merge tag 'linux-watchdog-6.11-rc1' of git://linux-watchdog.org/linux-watchdog
Pull watchdog updates from Wim Van Sebroeck:
- make watchdog_class const
- rework of the rzg2l_wdt driver
- other small fixes and improvements
* tag 'linux-watchdog-6.11-rc1' of git://www.linux-watchdog.org/linux-watchdog:
dt-bindings: watchdog: dlg,da9062-watchdog: Drop blank space
watchdog: rzn1: Convert comma to semicolon
watchdog: lenovo_se10_wdt: Convert comma to semicolon
dt-bindings: watchdog: renesas,wdt: Document RZ/G3S support
watchdog: rzg2l_wdt: Add suspend/resume support
watchdog: rzg2l_wdt: Rely on the reset driver for doing proper reset
watchdog: rzg2l_wdt: Remove comparison with zero
watchdog: rzg2l_wdt: Remove reset de-assert from probe
watchdog: rzg2l_wdt: Check return status of pm_runtime_put()
watchdog: rzg2l_wdt: Use pm_runtime_resume_and_get()
watchdog: rzg2l_wdt: Make the driver depend on PM
watchdog: rzg2l_wdt: Restrict the driver to ARCH_RZG2L and ARCH_R9A09G011
watchdog: imx7ulp_wdt: keep already running watchdog enabled
watchdog: starfive: Add missing clk_disable_unprepare()
watchdog: Make watchdog_class const
Linus Torvalds [Thu, 25 Jul 2024 17:10:34 +0000 (10:10 -0700)]
Merge tag 'dma-mapping-6.11-2024-07-24' of git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping fix from Christoph Hellwig:
- fix the order of actions in dmam_free_coherent (Lance Richardson)
* tag 'dma-mapping-6.11-2024-07-24' of git://git.infradead.org/users/hch/dma-mapping:
dma: fix call order in dmam_free_coherent
Jakub Kicinski [Thu, 25 Jul 2024 15:07:06 +0000 (08:07 -0700)]
Merge branch 'tap-tun-harden-by-dropping-short-frame'
Dongli Zhang says:
====================
tap/tun: harden by dropping short frame
This is to harden all of tap/tun to avoid any short frame smaller than the
Ethernet header (ETH_HLEN).
While the xen-netback already rejects short frame smaller than ETH_HLEN ...
914 static void xenvif_tx_build_gops(struct xenvif_queue *queue,
915 int budget,
916 unsigned *copy_ops,
917 unsigned *map_ops)
918 {
... ...
1007 if (unlikely(txreq.size < ETH_HLEN)) {
1008 netdev_dbg(queue->vif->dev,
1009 "Bad packet size: %d\n", txreq.size);
1010 xenvif_tx_err(queue, &txreq, extra_count, idx);
1011 break;
1012 }
... the short frame may not be dropped by vhost-net/tap/tun.
This fixes CVE-2024-41090 and CVE-2024-41091.
====================
Link: https://patch.msgid.link/20240724170452.16837-1-dongli.zhang@oracle.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Dongli Zhang [Wed, 24 Jul 2024 17:04:52 +0000 (10:04 -0700)]
tun: add missing verification for short frame
The cited commit missed to check against the validity of the frame length
in the tun_xdp_one() path, which could cause a corrupted skb to be sent
downstack. Even before the skb is transmitted, the
tun_xdp_one-->eth_type_trans() may access the Ethernet header although it
can be less than ETH_HLEN. Once transmitted, this could either cause
out-of-bound access beyond the actual length, or confuse the underlayer
with incorrect or inconsistent header length in the skb metadata.
In the alternative path, tun_get_user() already prohibits short frame which
has the length less than Ethernet header size from being transmitted for
IFF_TAP.
This is to drop any frame shorter than the Ethernet header size just like
how tun_get_user() does.
CVE: CVE-2024-41091
Inspired-by: https://lore.kernel.org/netdev/1717026141-25716-1-git-send-email-si-wei.liu@oracle.com/
Fixes:
043d222f93ab ("tuntap: accept an array of XDP buffs through sendmsg()")
Cc: stable@vger.kernel.org
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Reviewed-by: Si-Wei Liu <si-wei.liu@oracle.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Link: https://patch.msgid.link/20240724170452.16837-3-dongli.zhang@oracle.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Si-Wei Liu [Wed, 24 Jul 2024 17:04:51 +0000 (10:04 -0700)]
tap: add missing verification for short frame
The cited commit missed to check against the validity of the frame length
in the tap_get_user_xdp() path, which could cause a corrupted skb to be
sent downstack. Even before the skb is transmitted, the
tap_get_user_xdp()-->skb_set_network_header() may assume the size is more
than ETH_HLEN. Once transmitted, this could either cause out-of-bound
access beyond the actual length, or confuse the underlayer with incorrect
or inconsistent header length in the skb metadata.
In the alternative path, tap_get_user() already prohibits short frame which
has the length less than Ethernet header size from being transmitted.
This is to drop any frame shorter than the Ethernet header size just like
how tap_get_user() does.
CVE: CVE-2024-41090
Link: https://lore.kernel.org/netdev/1717026141-25716-1-git-send-email-si-wei.liu@oracle.com/
Fixes:
0efac27791ee ("tap: accept an array of XDP buffs through sendmsg()")
Cc: stable@vger.kernel.org
Signed-off-by: Si-Wei Liu <si-wei.liu@oracle.com>
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Link: https://patch.msgid.link/20240724170452.16837-2-dongli.zhang@oracle.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Dan Carpenter [Wed, 24 Jul 2024 16:08:18 +0000 (11:08 -0500)]
mISDN: Fix a use after free in hfcmulti_tx()
Don't dereference *sp after calling dev_kfree_skb(*sp).
Fixes:
af69fb3a8ffa ("Add mISDN HFC multiport driver")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/8be65f5a-c2dd-4ba0-8a10-bfe5980b8cfb@stanley.mountain
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Bailey Forrest [Wed, 24 Jul 2024 14:34:31 +0000 (07:34 -0700)]
gve: Fix an edge case for TSO skb validity check
The NIC requires each TSO segment to not span more than 10
descriptors. NIC further requires each descriptor to not exceed
16KB - 1 (GVE_TX_MAX_BUF_SIZE_DQO).
The descriptors for an skb are generated by
gve_tx_add_skb_no_copy_dqo() for DQO RDA queue format.
gve_tx_add_skb_no_copy_dqo() loops through each skb frag and
generates a descriptor for the entire frag if the frag size is
not greater than GVE_TX_MAX_BUF_SIZE_DQO. If the frag size is
greater than GVE_TX_MAX_BUF_SIZE_DQO, it is split into descriptor(s)
of size GVE_TX_MAX_BUF_SIZE_DQO and a descriptor is generated for
the remainder (frag size % GVE_TX_MAX_BUF_SIZE_DQO).
gve_can_send_tso() checks if the descriptors thus generated for an
skb would meet the requirement that each TSO-segment not span more
than 10 descriptors. However, the current code misses an edge case
when a TSO segment spans multiple descriptors within a large frag.
This change fixes the edge case.
gve_can_send_tso() relies on the assumption that max gso size (9728)
is less than GVE_TX_MAX_BUF_SIZE_DQO and therefore within an skb
fragment a TSO segment can never span more than 2 descriptors.
Fixes:
a57e5de476be ("gve: DQO: Add TX path")
Signed-off-by: Praveen Kaligineedi <pkaligineedi@google.com>
Signed-off-by: Bailey Forrest <bcf@google.com>
Reviewed-by: Jeroen de Borst <jeroendb@google.com>
Cc: stable@vger.kernel.org
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20240724143431.3343722-1-pkaligineedi@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
projects / linux-2.6-block.git / log