[PATCH 5.15 07/78] objtool: Shrink struct instruction

Greg Kroah-Hartman
2022-07-12T19:03:15Z

From: Peter Zijlstra <peterz@infradead.org>

commit c509331b41b7365e17396c246e8c5797bccc8074 upstream.

Any one instruction can only ever call a single function, therefore
insn->mcount_loc_node is superfluous and can use insn->call_node.

This shrinks struct instruction, which is by far the most numerous
structure objtool creates.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20211026120309.785456706@infradead.org
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
tools/objtool/check.c | 6 +++---
tools/objtool/include/objtool/check.h | 1 -
2 files changed, 3 insertions(+), 4 deletions(-)

--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -551,7 +551,7 @@ static int create_mcount_loc_sections(st
return 0;

idx = 0;
- list_for_each_entry(insn, &file->mcount_loc_list, mcount_loc_node)
+ list_for_each_entry(insn, &file->mcount_loc_list, call_node)
idx++;

sec = elf_create_section(file->elf, "__mcount_loc", 0, sizeof(unsigned long), idx);
@@ -559,7 +559,7 @@ static int create_mcount_loc_sections(st
return -1;

idx = 0;
- list_for_each_entry(insn, &file->mcount_loc_list, mcount_loc_node) {
+ list_for_each_entry(insn, &file->mcount_loc_list, call_node) {

loc = (unsigned long *)sec->data->d_buf + idx;
memset(loc, 0, sizeof(unsigned long));
@@ -909,7 +909,7 @@ static void annotate_call_site(struct ob

insn->type = INSN_NOP;

- list_add_tail(&insn->mcount_loc_node, &file->mcount_loc_list);
+ list_add_tail(&insn->call_node, &file->mcount_loc_list);
return;
}
}
--- a/tools/objtool/include/objtool/check.h
+++ b/tools/objtool/include/objtool/check.h
@@ -40,7 +40,6 @@ struct instruction {
struct list_head list;
struct hlist_node hash;
struct list_head call_node;
- struct list_head mcount_loc_node;
struct section *sec;
unsigned long offset;
unsigned int len;