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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-28 10:16:15 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-28 10:16:15 -0700 |
| commit | 7ecb59a56666506ebb1197f89ca7d587bd83309e (patch) | |
| tree | 81ad7f30114cd4f2ada4a5631636581f9ff7544e /tools/objtool/arch | |
| parent | a358505d8af3ab43763e1b49549619528783d2bf (diff) | |
| parent | 0f1441b44e823a74f3f3780902a113e07c73fbf6 (diff) | |
| download | linux-7ecb59a56666506ebb1197f89ca7d587bd83309e.tar.bz2 | |
Merge tag 'objtool_urgent_for_5.8_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull objtool fixes from Borislav Petkov:
"Three fixes from Peter Zijlstra suppressing KCOV instrumentation in
noinstr sections.
Peter Zijlstra says:
"Address KCOV vs noinstr. There is no function attribute to
selectively suppress KCOV instrumentation, instead teach objtool
to NOP out the calls in noinstr functions"
This cures a bunch of KCOV crashes (as used by syzcaller)"
* tag 'objtool_urgent_for_5.8_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
objtool: Fix noinstr vs KCOV
objtool: Provide elf_write_{insn,reloc}()
objtool: Clean up elf_write() condition
Diffstat (limited to 'tools/objtool/arch')
| -rw-r--r-- | tools/objtool/arch/x86/decode.c | 18 | ||||
| -rw-r--r-- | tools/objtool/arch/x86/include/arch_elf.h | 6 |
2 files changed, 24 insertions, 0 deletions
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c index 4b504fc90bbb..9872195f998b 100644 --- a/tools/objtool/arch/x86/decode.c +++ b/tools/objtool/arch/x86/decode.c @@ -565,3 +565,21 @@ void arch_initial_func_cfi_state(struct cfi_init_state *state) state->regs[16].base = CFI_CFA; state->regs[16].offset = -8; } + +const char *arch_nop_insn(int len) +{ + static const char nops[5][5] = { + /* 1 */ { 0x90 }, + /* 2 */ { 0x66, 0x90 }, + /* 3 */ { 0x0f, 0x1f, 0x00 }, + /* 4 */ { 0x0f, 0x1f, 0x40, 0x00 }, + /* 5 */ { 0x0f, 0x1f, 0x44, 0x00, 0x00 }, + }; + + if (len < 1 || len > 5) { + WARN("invalid NOP size: %d\n", len); + return NULL; + } + + return nops[len-1]; +} diff --git a/tools/objtool/arch/x86/include/arch_elf.h b/tools/objtool/arch/x86/include/arch_elf.h new file mode 100644 index 000000000000..69cc4264b28a --- /dev/null +++ b/tools/objtool/arch/x86/include/arch_elf.h @@ -0,0 +1,6 @@ +#ifndef _OBJTOOL_ARCH_ELF +#define _OBJTOOL_ARCH_ELF + +#define R_NONE R_X86_64_NONE + +#endif /* _OBJTOOL_ARCH_ELF */ |