x86/static_call: Add inline static call implementation for x86-64
Add the inline static call implementation for x86-64. The generated code
is identical to the out-of-line case, except we move the trampoline into
it's own section.
Objtool uses the trampoline naming convention to detect all the call
sites. It then annotates those call sites in the .static_call_sites
section.
During boot (and module init), the call sites are patched to call
directly into the destination function. The temporary trampoline is
then no longer used.
[peterz: merged trampolines, put trampoline in section]
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20200818135804.864271425@infradead.org
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index 3ddbd66..4e1d746 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -652,7 +652,7 @@ struct elf *elf_open_read(const char *name, int flags)
}
struct section *elf_create_section(struct elf *elf, const char *name,
- size_t entsize, int nr)
+ unsigned int sh_flags, size_t entsize, int nr)
{
struct section *sec, *shstrtab;
size_t size = entsize * nr;
@@ -712,7 +712,7 @@ struct section *elf_create_section(struct elf *elf, const char *name,
sec->sh.sh_entsize = entsize;
sec->sh.sh_type = SHT_PROGBITS;
sec->sh.sh_addralign = 1;
- sec->sh.sh_flags = SHF_ALLOC;
+ sec->sh.sh_flags = SHF_ALLOC | sh_flags;
/* Add section name to .shstrtab (or .strtab for Clang) */
@@ -767,7 +767,7 @@ static struct section *elf_create_rel_reloc_section(struct elf *elf, struct sect
strcpy(relocname, ".rel");
strcat(relocname, base->name);
- sec = elf_create_section(elf, relocname, sizeof(GElf_Rel), 0);
+ sec = elf_create_section(elf, relocname, 0, sizeof(GElf_Rel), 0);
free(relocname);
if (!sec)
return NULL;
@@ -797,7 +797,7 @@ static struct section *elf_create_rela_reloc_section(struct elf *elf, struct sec
strcpy(relocname, ".rela");
strcat(relocname, base->name);
- sec = elf_create_section(elf, relocname, sizeof(GElf_Rela), 0);
+ sec = elf_create_section(elf, relocname, 0, sizeof(GElf_Rela), 0);
free(relocname);
if (!sec)
return NULL;