diff options
| author | Josh Poimboeuf <jpoimboe@redhat.com> | 2018-01-11 21:46:23 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-01-17 09:38:58 +0100 |
| commit | 3adb52ab29760624cd59ea0579317a24c4827e9f (patch) | |
| tree | 36c06a177bb28fc7463af154dfc381c11ef6774e /tools/objtool | |
| parent | 35aee626fa6311c3942fedd50c50f6748922e89f (diff) | |
objtool: Detect jumps to retpoline thunks
commit 39b735332cb8b33a27c28592d969e4016c86c3ea upstream.
A direct jump to a retpoline thunk is really an indirect jump in
disguise. Change the objtool instruction type accordingly.
Objtool needs to know where indirect branches are so it can detect
switch statement jump tables.
This fixes a bunch of warnings with CONFIG_RETPOLINE like:
arch/x86/events/intel/uncore_nhmex.o: warning: objtool: nhmex_rbox_msr_enable_event()+0x44: sibling call from callable instruction with modified stack frame
kernel/signal.o: warning: objtool: copy_siginfo_to_user()+0x91: sibling call from callable instruction with modified stack frame
...
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: Rik van Riel <riel@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: thomas.lendacky@amd.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kees Cook <keescook@google.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Cc: Paul Turner <pjt@google.com>
Link: https://lkml.kernel.org/r/1515707194-20531-2-git-send-email-dwmw@amazon.co.uk
[dwmw2: Applies to tools/objtool/builtin-check.c not check.c]
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'tools/objtool')
| -rw-r--r-- | tools/objtool/builtin-check.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c index f8b6cf5fec87..293a23e27968 100644 --- a/tools/objtool/builtin-check.c +++ b/tools/objtool/builtin-check.c @@ -382,6 +382,13 @@ static int add_jump_destinations(struct objtool_file *file) } else if (rela->sym->sec->idx) { dest_sec = rela->sym->sec; dest_off = rela->sym->sym.st_value + rela->addend + 4; + } else if (strstr(rela->sym->name, "_indirect_thunk_")) { + /* + * Retpoline jumps are really dynamic jumps in + * disguise, so convert them accordingly. + */ + insn->type = INSN_JUMP_DYNAMIC; + continue; } else { /* sibling call */ insn->jump_dest = 0; |