selftests/bpf: Avoid passing out-of-range values to __retval()
authorPeilin Ye <yepeilin@google.com>
Wed, 7 May 2025 03:43:19 +0000 (03:43 +0000)
committerAlexei Starovoitov <ast@kernel.org>
Fri, 9 May 2025 17:05:27 +0000 (10:05 -0700)
Currently, we pass 0x1234567890abcdef to __retval() for the following
two tests:

  verifier_load_acquire/load_acquire_64
  verifier_store_release/store_release_64

However, the upper 32 bits of that value are being ignored, since
__retval() expects an int.  Actually, the tests would still pass even if
I change '__retval(0x1234567890abcdef)' to e.g. '__retval(0x90abcdef)'.

Restructure the tests a bit to test the entire 64-bit values properly.
Do the same to their 8-, 16- and 32-bit variants as well to keep the
style consistent.

Fixes: ff3afe5da998 ("selftests/bpf: Add selftests for load-acquire and store-release instructions")
Acked-by: Björn Töpel <bjorn@kernel.org>
Reviewed-by: Pu Lehui <pulehui@huawei.com>
Tested-by: Björn Töpel <bjorn@rivosinc.com> # QEMU/RVA23
Signed-off-by: Peilin Ye <yepeilin@google.com>
Link: https://lore.kernel.org/r/d67f4c6f6ee0d0388cbce1f4892ec4176ee2d604.1746588351.git.yepeilin@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
tools/testing/selftests/bpf/progs/verifier_load_acquire.c
tools/testing/selftests/bpf/progs/verifier_store_release.c

index 77698d5a19e446a725ccb7364ce6aab43b694bf5..a696ab84bfd6626fe36d7976be81aefe5c6113a2 100644 (file)
 
 SEC("socket")
 __description("load-acquire, 8-bit")
-__success __success_unpriv __retval(0x12)
+__success __success_unpriv __retval(0)
 __naked void load_acquire_8(void)
 {
        asm volatile (
+       "r0 = 0;"
        "w1 = 0x12;"
        "*(u8 *)(r10 - 1) = w1;"
-       ".8byte %[load_acquire_insn];" // w0 = load_acquire((u8 *)(r10 - 1));
+       ".8byte %[load_acquire_insn];" // w2 = load_acquire((u8 *)(r10 - 1));
+       "if r2 == r1 goto 1f;"
+       "r0 = 1;"
+"1:"
        "exit;"
        :
        : __imm_insn(load_acquire_insn,
-                    BPF_ATOMIC_OP(BPF_B, BPF_LOAD_ACQ, BPF_REG_0, BPF_REG_10, -1))
+                    BPF_ATOMIC_OP(BPF_B, BPF_LOAD_ACQ, BPF_REG_2, BPF_REG_10, -1))
        : __clobber_all);
 }
 
 SEC("socket")
 __description("load-acquire, 16-bit")
-__success __success_unpriv __retval(0x1234)
+__success __success_unpriv __retval(0)
 __naked void load_acquire_16(void)
 {
        asm volatile (
+       "r0 = 0;"
        "w1 = 0x1234;"
        "*(u16 *)(r10 - 2) = w1;"
-       ".8byte %[load_acquire_insn];" // w0 = load_acquire((u16 *)(r10 - 2));
+       ".8byte %[load_acquire_insn];" // w2 = load_acquire((u16 *)(r10 - 2));
+       "if r2 == r1 goto 1f;"
+       "r0 = 1;"
+"1:"
        "exit;"
        :
        : __imm_insn(load_acquire_insn,
-                    BPF_ATOMIC_OP(BPF_H, BPF_LOAD_ACQ, BPF_REG_0, BPF_REG_10, -2))
+                    BPF_ATOMIC_OP(BPF_H, BPF_LOAD_ACQ, BPF_REG_2, BPF_REG_10, -2))
        : __clobber_all);
 }
 
 SEC("socket")
 __description("load-acquire, 32-bit")
-__success __success_unpriv __retval(0x12345678)
+__success __success_unpriv __retval(0)
 __naked void load_acquire_32(void)
 {
        asm volatile (
+       "r0 = 0;"
        "w1 = 0x12345678;"
        "*(u32 *)(r10 - 4) = w1;"
-       ".8byte %[load_acquire_insn];" // w0 = load_acquire((u32 *)(r10 - 4));
+       ".8byte %[load_acquire_insn];" // w2 = load_acquire((u32 *)(r10 - 4));
+       "if r2 == r1 goto 1f;"
+       "r0 = 1;"
+"1:"
        "exit;"
        :
        : __imm_insn(load_acquire_insn,
-                    BPF_ATOMIC_OP(BPF_W, BPF_LOAD_ACQ, BPF_REG_0, BPF_REG_10, -4))
+                    BPF_ATOMIC_OP(BPF_W, BPF_LOAD_ACQ, BPF_REG_2, BPF_REG_10, -4))
        : __clobber_all);
 }
 
 SEC("socket")
 __description("load-acquire, 64-bit")
-__success __success_unpriv __retval(0x1234567890abcdef)
+__success __success_unpriv __retval(0)
 __naked void load_acquire_64(void)
 {
        asm volatile (
+       "r0 = 0;"
        "r1 = 0x1234567890abcdef ll;"
        "*(u64 *)(r10 - 8) = r1;"
-       ".8byte %[load_acquire_insn];" // r0 = load_acquire((u64 *)(r10 - 8));
+       ".8byte %[load_acquire_insn];" // r2 = load_acquire((u64 *)(r10 - 8));
+       "if r2 == r1 goto 1f;"
+       "r0 = 1;"
+"1:"
        "exit;"
        :
        : __imm_insn(load_acquire_insn,
-                    BPF_ATOMIC_OP(BPF_DW, BPF_LOAD_ACQ, BPF_REG_0, BPF_REG_10, -8))
+                    BPF_ATOMIC_OP(BPF_DW, BPF_LOAD_ACQ, BPF_REG_2, BPF_REG_10, -8))
        : __clobber_all);
 }
 
index 7e456e2861b4741ed37a6849dc37df71338735e2..72f1eb0060748aed2f15bdf7d0d056d1dee8bb92 100644 (file)
 
 SEC("socket")
 __description("store-release, 8-bit")
-__success __success_unpriv __retval(0x12)
+__success __success_unpriv __retval(0)
 __naked void store_release_8(void)
 {
        asm volatile (
+       "r0 = 0;"
        "w1 = 0x12;"
        ".8byte %[store_release_insn];" // store_release((u8 *)(r10 - 1), w1);
-       "w0 = *(u8 *)(r10 - 1);"
+       "w2 = *(u8 *)(r10 - 1);"
+       "if r2 == r1 goto 1f;"
+       "r0 = 1;"
+"1:"
        "exit;"
        :
        : __imm_insn(store_release_insn,
@@ -26,13 +30,17 @@ __naked void store_release_8(void)
 
 SEC("socket")
 __description("store-release, 16-bit")
-__success __success_unpriv __retval(0x1234)
+__success __success_unpriv __retval(0)
 __naked void store_release_16(void)
 {
        asm volatile (
+       "r0 = 0;"
        "w1 = 0x1234;"
        ".8byte %[store_release_insn];" // store_release((u16 *)(r10 - 2), w1);
-       "w0 = *(u16 *)(r10 - 2);"
+       "w2 = *(u16 *)(r10 - 2);"
+       "if r2 == r1 goto 1f;"
+       "r0 = 1;"
+"1:"
        "exit;"
        :
        : __imm_insn(store_release_insn,
@@ -42,13 +50,17 @@ __naked void store_release_16(void)
 
 SEC("socket")
 __description("store-release, 32-bit")
-__success __success_unpriv __retval(0x12345678)
+__success __success_unpriv __retval(0)
 __naked void store_release_32(void)
 {
        asm volatile (
+       "r0 = 0;"
        "w1 = 0x12345678;"
        ".8byte %[store_release_insn];" // store_release((u32 *)(r10 - 4), w1);
-       "w0 = *(u32 *)(r10 - 4);"
+       "w2 = *(u32 *)(r10 - 4);"
+       "if r2 == r1 goto 1f;"
+       "r0 = 1;"
+"1:"
        "exit;"
        :
        : __imm_insn(store_release_insn,
@@ -58,13 +70,17 @@ __naked void store_release_32(void)
 
 SEC("socket")
 __description("store-release, 64-bit")
-__success __success_unpriv __retval(0x1234567890abcdef)
+__success __success_unpriv __retval(0)
 __naked void store_release_64(void)
 {
        asm volatile (
+       "r0 = 0;"
        "r1 = 0x1234567890abcdef ll;"
        ".8byte %[store_release_insn];" // store_release((u64 *)(r10 - 8), r1);
-       "r0 = *(u64 *)(r10 - 8);"
+       "r2 = *(u64 *)(r10 - 8);"
+       "if r2 == r1 goto 1f;"
+       "r0 = 1;"
+"1:"
        "exit;"
        :
        : __imm_insn(store_release_insn,