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Subject[PATCH v2 01/14] objtool: Tag retpoline thunk symbols
In order to avoid calling arch_is_retpoline() (which does a strcmp)
over and over on symbols, tag them once upfront.

XXX do we also want to do __fentry__ ?
XXX do we want an enum instead of a bunch of bools ?

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
tools/objtool/check.c | 17 +++++++++++------
tools/objtool/include/objtool/elf.h | 1 +
2 files changed, 12 insertions(+), 6 deletions(-)

--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -1077,7 +1077,7 @@ 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 (arch_is_retpoline(reloc->sym)) {
+ } else if (reloc->sym->retpoline_thunk) {
/*
* Retpoline jumps are really dynamic jumps in
* disguise, so convert them accordingly.
@@ -1218,7 +1218,7 @@ static int add_call_destinations(struct

add_call_dest(file, insn, dest, false);

- } else if (arch_is_retpoline(reloc->sym)) {
+ } else if (reloc->sym->retpoline_thunk) {
/*
* Retpoline calls are really dynamic calls in
* disguise, so convert them accordingly.
@@ -1907,17 +1907,22 @@ static int read_intra_function_calls(str
return 0;
}

-static int read_static_call_tramps(struct objtool_file *file)
+static int classify_symbols(struct objtool_file *file)
{
struct section *sec;
struct symbol *func;

for_each_sec(file, sec) {
list_for_each_entry(func, &sec->symbol_list, list) {
- if (func->bind == STB_GLOBAL &&
- !strncmp(func->name, STATIC_CALL_TRAMP_PREFIX_STR,
+ if (func->bind != STB_GLOBAL)
+ continue;
+
+ if (!strncmp(func->name, STATIC_CALL_TRAMP_PREFIX_STR,
strlen(STATIC_CALL_TRAMP_PREFIX_STR)))
func->static_call_tramp = true;
+
+ if (arch_is_retpoline(func))
+ func->retpoline_thunk = true;
}
}

@@ -1983,7 +1988,7 @@ static int decode_sections(struct objtoo
/*
* Must be before add_{jump_call}_destination.
*/
- ret = read_static_call_tramps(file);
+ ret = classify_symbols(file);
if (ret)
return ret;

--- a/tools/objtool/include/objtool/elf.h
+++ b/tools/objtool/include/objtool/elf.h
@@ -56,6 +56,7 @@ struct symbol {
struct symbol *pfunc, *cfunc, *alias;
bool uaccess_safe;
bool static_call_tramp;
+ bool retpoline_thunk;
struct list_head pv_target;
};


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