From: Josh Poimboeuf jpoimboe@redhat.com
[ Upstream commit e6da9567959e164f82bc81967e0d5b10dee870b4 ]
The ignore flag is set on fake jumps in order to keep add_jump_destinations() from setting their jump_dest, since it already got set when the fake jump was created.
But using the ignore flag is a bit of a hack. It's normally used to skip validation of an instruction, which doesn't really make sense for fake jumps.
Also, after the next patch, using the ignore flag for fake jumps can trigger a false "why am I validating an ignored function?" warning.
Instead just add an explicit check in add_jump_destinations() to skip fake jumps.
Signed-off-by: Josh Poimboeuf jpoimboe@redhat.com Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Peter Zijlstra peterz@infradead.org Cc: Thomas Gleixner tglx@linutronix.de Link: http://lkml.kernel.org/r/71abc072ff48b2feccc197723a9c52859476c068.1557766718... Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- tools/objtool/check.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 46be345766203..02a47e365e52d 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -28,6 +28,8 @@ #include <linux/hashtable.h> #include <linux/kernel.h>
+#define FAKE_JUMP_OFFSET -1 + struct alternative { struct list_head list; struct instruction *insn; @@ -501,7 +503,7 @@ static int add_jump_destinations(struct objtool_file *file) insn->type != INSN_JUMP_UNCONDITIONAL) continue;
- if (insn->ignore) + if (insn->ignore || insn->offset == FAKE_JUMP_OFFSET) continue;
rela = find_rela_by_dest_range(insn->sec, insn->offset, @@ -670,10 +672,10 @@ static int handle_group_alt(struct objtool_file *file, clear_insn_state(&fake_jump->state);
fake_jump->sec = special_alt->new_sec; - fake_jump->offset = -1; + fake_jump->offset = FAKE_JUMP_OFFSET; fake_jump->type = INSN_JUMP_UNCONDITIONAL; fake_jump->jump_dest = list_next_entry(last_orig_insn, list); - fake_jump->ignore = true; + fake_jump->func = orig_insn->func; }
if (!special_alt->new_len) {