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objtool: Cache instruction relocs

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commit 7bd2a600f3e9d27286bbf23c83d599e9cc7cf245 upstream.

Track the reloc of instructions in the new instruction->reloc field
to avoid having to look them up again later.

( Technically x86 instructions can have two relocations, but not jumps
  and calls, for which we're using this. )

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/20210326151300.195441549@infradead.org
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Peter Zijlstra 2021-03-26 16:12:13 +01:00 committed by Greg Kroah-Hartman
parent 33092b4866
commit e87c18c4a9
2 changed files with 23 additions and 6 deletions
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28
tools/objtool/check.c
View File

@ -754,6 +754,25 @@ __weak bool arch_is_retpoline(struct symbol *sym)
return false;
}
#define NEGATIVE_RELOC ((void *)-1L)
static struct reloc *insn_reloc(struct objtool_file *file, struct instruction *insn)
{
if (insn->reloc == NEGATIVE_RELOC)
return NULL;
if (!insn->reloc) {
insn->reloc = find_reloc_by_dest_range(file->elf, insn->sec,
insn->offset, insn->len);
if (!insn->reloc) {
insn->reloc = NEGATIVE_RELOC;
return NULL;
}
}
return insn->reloc;
}
/*
* Find the destination instructions for all jumps.
*/
@ -768,8 +787,7 @@ static int add_jump_destinations(struct objtool_file *file)
if (!is_static_jump(insn))
continue;
reloc = find_reloc_by_dest_range(file->elf, insn->sec,
insn->offset, insn->len);
reloc = insn_reloc(file, insn);
if (!reloc) {
dest_sec = insn->sec;
dest_off = arch_jump_destination(insn);
@ -901,8 +919,7 @@ static int add_call_destinations(struct objtool_file *file)
if (insn->type != INSN_CALL)
continue;
reloc = find_reloc_by_dest_range(file->elf, insn->sec,
insn->offset, insn->len);
reloc = insn_reloc(file, insn);
if (!reloc) {
dest_off = arch_jump_destination(insn);
insn->call_dest = find_call_destination(insn->sec, dest_off);
@ -1085,8 +1102,7 @@ static int handle_group_alt(struct objtool_file *file,
* alternatives code can adjust the relative offsets
* accordingly.
*/
alt_reloc = find_reloc_by_dest_range(file->elf, insn->sec,
insn->offset, insn->len);
alt_reloc = insn_reloc(file, insn);
if (alt_reloc &&
!arch_support_alt_relocation(special_alt, insn, alt_reloc)) {

1
tools/objtool/check.h
View File

@ -55,6 +55,7 @@ struct instruction {
struct instruction *jump_dest;
struct instruction *first_jump_src;
struct reloc *jump_table;
struct reloc *reloc;
struct list_head alts;
struct symbol *func;
struct list_head stack_ops;