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objtool: Read the NOENDBR annotation

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Read the new NOENDBR annotation. While there, attempt to not bloat
struct instruction.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154319.586815435@infradead.org
This commit is contained in:
Peter Zijlstra 2022-03-08 16:30:52 +01:00
parent 3515899bef
commit 96db4a988d
2 changed files with 37 additions and 3 deletions
tools/objtool
check.c
include/objtool
check.h

27
tools/objtool/check.c
View File

@ -1866,6 +1866,29 @@ static int read_unwind_hints(struct objtool_file *file)
return 0;
}
static int read_noendbr_hints(struct objtool_file *file)
{
struct section *sec;
struct instruction *insn;
struct reloc *reloc;
sec = find_section_by_name(file->elf, ".rela.discard.noendbr");
if (!sec)
return 0;
list_for_each_entry(reloc, &sec->reloc_list, list) {
insn = find_insn(file, reloc->sym->sec, reloc->sym->offset + reloc->addend);
if (!insn) {
WARN("bad .discard.noendbr entry");
return -1;
}
insn->noendbr = 1;
}
return 0;
}
static int read_retpoline_hints(struct objtool_file *file)
{
struct section *sec;
@ -2099,6 +2122,10 @@ static int decode_sections(struct objtool_file *file)
if (ret)
return ret;
ret = read_noendbr_hints(file);
if (ret)
return ret;
/*
* Must be before add_{jump_call}_destination.
*/

13
tools/objtool/include/objtool/check.h
View File

@ -45,11 +45,18 @@ struct instruction {
unsigned int len;
enum insn_type type;
unsigned long immediate;
bool dead_end, ignore, ignore_alts;
bool hint;
bool retpoline_safe;
u8 dead_end : 1,
ignore : 1,
ignore_alts : 1,
hint : 1,
retpoline_safe : 1,
noendbr : 1;
/* 2 bit hole */
s8 instr;
u8 visited;
/* u8 hole */
struct alt_group *alt_group;
struct symbol *call_dest;
struct instruction *jump_dest;