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| author | Peter Zijlstra <peterz@infradead.org> | 2022-09-15 13:11:07 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2022-10-17 16:41:06 +0200 |
| commit | 61c6065ef7ec0447a280179d04b2d81c80c2f479 (patch) | |
| tree | 70c644b377d898e2be2ca53ec465424fbf3013d0 /tools | |
| parent | 5b71ac8a2a3185da34a6556e791b533b48183a41 (diff) | |
| download | linux-stable-61c6065ef7ec0447a280179d04b2d81c80c2f479.tar.gz linux-stable-61c6065ef7ec0447a280179d04b2d81c80c2f479.tar.bz2 linux-stable-61c6065ef7ec0447a280179d04b2d81c80c2f479.zip | |
objtool: Allow !PC relative relocations
Objtool doesn't currently much like per-cpu usage in alternatives:
arch/x86/entry/entry_64.o: warning: objtool: .altinstr_replacement+0xf: unsupported relocation in alternatives section
f: 65 c7 04 25 00 00 00 00 00 00 00 80 movl $0x80000000,%gs:0x0 13: R_X86_64_32S __x86_call_depth
Since the R_X86_64_32S relocation is location invariant (it's
computation doesn't include P - the address of the location itself),
it can be trivially allowed.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220915111145.806607235@infradead.org
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/objtool/arch/x86/decode.c | 24 | ||||
| -rw-r--r-- | tools/objtool/check.c | 2 | ||||
| -rw-r--r-- | tools/objtool/include/objtool/arch.h | 2 |
3 files changed, 27 insertions, 1 deletions
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c index 1c253b4b7ce0..f0943830add7 100644 --- a/tools/objtool/arch/x86/decode.c +++ b/tools/objtool/arch/x86/decode.c @@ -73,6 +73,30 @@ unsigned long arch_jump_destination(struct instruction *insn) return insn->offset + insn->len + insn->immediate; } +bool arch_pc_relative_reloc(struct reloc *reloc) +{ + /* + * All relocation types where P (the address of the target) + * is included in the computation. + */ + switch (reloc->type) { + case R_X86_64_PC8: + case R_X86_64_PC16: + case R_X86_64_PC32: + case R_X86_64_PC64: + + case R_X86_64_PLT32: + case R_X86_64_GOTPC32: + case R_X86_64_GOTPCREL: + return true; + + default: + break; + } + + return false; +} + #define ADD_OP(op) \ if (!(op = calloc(1, sizeof(*op)))) \ return -1; \ diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 43ec14c29a60..7174bba14494 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -1645,7 +1645,7 @@ static int handle_group_alt(struct objtool_file *file, * accordingly. */ alt_reloc = insn_reloc(file, insn); - if (alt_reloc && + if (alt_reloc && arch_pc_relative_reloc(alt_reloc) && !arch_support_alt_relocation(special_alt, insn, alt_reloc)) { WARN_FUNC("unsupported relocation in alternatives section", diff --git a/tools/objtool/include/objtool/arch.h b/tools/objtool/include/objtool/arch.h index beb2f3aa94ff..fe2ea4b892c3 100644 --- a/tools/objtool/include/objtool/arch.h +++ b/tools/objtool/include/objtool/arch.h @@ -93,4 +93,6 @@ bool arch_is_rethunk(struct symbol *sym); int arch_rewrite_retpolines(struct objtool_file *file); +bool arch_pc_relative_reloc(struct reloc *reloc); + #endif /* _ARCH_H */ |