[PATCH v3 05/16] objtool: Per arch retpoline naming

From: Peter Zijlstra
Date: Fri Mar 26 2021 - 11:14:41 EST


The __x86_indirect_ naming is obviously not generic. Shorten to allow
matching some additional magic names later.

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
tools/objtool/arch/x86/decode.c | 5 +++++
tools/objtool/check.c | 9 +++++++--
tools/objtool/include/objtool/arch.h | 2 ++
3 files changed, 14 insertions(+), 2 deletions(-)

--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -692,3 +692,8 @@ int arch_decode_hint_reg(struct instruct

return 0;
}
+
+bool arch_is_retpoline(struct symbol *sym)
+{
+ return !strncmp(sym->name, "__x86_indirect_", 15);
+}
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -850,6 +850,11 @@ static int add_ignore_alternatives(struc
return 0;
}

+__weak bool arch_is_retpoline(struct symbol *sym)
+{
+ return false;
+}
+
/*
* Find the destination instructions for all jumps.
*/
@@ -872,7 +877,7 @@ static int add_jump_destinations(struct
} else if (reloc->sym->type == STT_SECTION) {
dest_sec = reloc->sym->sec;
dest_off = arch_dest_reloc_offset(reloc->addend);
- } else if (!strncmp(reloc->sym->name, "__x86_indirect_thunk_", 21)) {
+ } else if (arch_is_retpoline(reloc->sym)) {
/*
* Retpoline jumps are really dynamic jumps in
* disguise, so convert them accordingly.
@@ -1026,7 +1031,7 @@ static int add_call_destinations(struct
return -1;
}

- } else if (!strncmp(reloc->sym->name, "__x86_indirect_thunk_", 21)) {
+ } else if (arch_is_retpoline(reloc->sym)) {
/*
* Retpoline calls are really dynamic calls in
* disguise, so convert them accordingly.
--- a/tools/objtool/include/objtool/arch.h
+++ b/tools/objtool/include/objtool/arch.h
@@ -85,4 +85,6 @@ const char *arch_nop_insn(int len);

int arch_decode_hint_reg(struct instruction *insn, u8 sp_reg);

+bool arch_is_retpoline(struct symbol *sym);
+
#endif /* _ARCH_H */