objtool: Handle per arch retpoline naming

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

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/20210326151259.630296706@infradead.org

diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index ba9ebff..782894e 100644 (file)
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -648,3 +648,8 @@ int arch_decode_hint_reg(struct instruction *insn, u8 sp_reg)
 
        return 0;
 }
+
+bool arch_is_retpoline(struct symbol *sym)
+{
+       return !strncmp(sym->name, "__x86_indirect_", 15);
+}

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 519af4b..6fbc001 100644 (file)
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -850,6 +850,11 @@ static int add_ignore_alternatives(struct objtool_file *file)
        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 objtool_file *file)
                } 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 objtool_file *file)
                                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.

diff --git a/tools/objtool/include/objtool/arch.h b/tools/objtool/include/objtool/arch.h
index 6ff0685..bb30993 100644 (file)
--- a/tools/objtool/include/objtool/arch.h
+++ b/tools/objtool/include/objtool/arch.h
@@ -86,4 +86,6 @@ 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 */