From ad14f7ca9f0d9fdf73d1fd61aaf8248d46ffc849 Mon Sep 17 00:00:00 2001 From: Vladimir Isaev Date: Wed, 13 Mar 2024 10:35:46 +0300 Subject: [PATCH] riscv: hwprobe: do not produce frtace relocation Such relocation causes crash of android linker similar to one described in commit e05d57dcb8c7 ("riscv: Fixup __vdso_gettimeofday broke dynamic ftrace"). Looks like this relocation is added by CONFIG_DYNAMIC_FTRACE which is disabled in the default android kernel. Before: readelf -rW arch/riscv/kernel/vdso/vdso.so: Relocation section '.rela.dyn' at offset 0xd00 contains 1 entry: Offset Info Type 0000000000000d20 0000000000000003 R_RISCV_RELATIVE objdump: 0000000000000c86 <__vdso_riscv_hwprobe@@LINUX_4.15>: c86: 0001 nop c88: 0001 nop c8a: 0001 nop c8c: 0001 nop c8e: e211 bnez a2,c92 <__vdso_riscv_hwprobe... After: readelf -rW arch/riscv/kernel/vdso/vdso.so: There are no relocations in this file. objdump: 0000000000000c86 <__vdso_riscv_hwprobe@@LINUX_4.15>: c86: e211 bnez a2,c8a <__vdso_riscv_hwprobe... c88: c6b9 beqz a3,cd6 <__vdso_riscv_hwprobe... c8a: e739 bnez a4,cd8 <__vdso_riscv_hwprobe... c8c: ffffd797 auipc a5,0xffffd Also disable SCS since it also should not be available in vdso. Fixes: aa5af0aa90ba ("RISC-V: Add hwprobe vDSO function and data") Signed-off-by: Roman Artemev Signed-off-by: Vladimir Isaev Reviewed-by: Alexandre Ghiti Reviewed-by: Guo Ren Link: https://lore.kernel.org/r/20240313085843.17661-1-vladimir.isaev@syntacore.com Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/vdso/Makefile | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile index 9b517fe1b8a8..272c431ac5b9 100644 --- a/arch/riscv/kernel/vdso/Makefile +++ b/arch/riscv/kernel/vdso/Makefile @@ -37,6 +37,7 @@ endif # Disable -pg to prevent insert call site CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS) +CFLAGS_REMOVE_hwprobe.o = $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS) # Disable profiling and instrumentation for VDSO code GCOV_PROFILE := n -- 2.25.1