On 06/30/2017 04:03 PM, Michael Matz wrote:
> So you need to find some other solution of setting up the stack for ASAN.
> And it'd be best if that solution doesn't require inserting code inside
> the above sequence of parameter setup instructions, and you certainly
> can't call any functions inside that sequence. It might mean that you
> can't track the static chain place or the nonlocal goto save area. You
> also don't track the parameter stack slots, right?
Hi.
Hopefully following patch will fix that. I returned to the first version and
saved/restored static_chain register before/after __asan_stack_malloc.
Patch can bootstrap on ppc64le-redhat-linux and survives regression tests.
Thoughts?
Martin
>From b285e7cb1d7f3e35981dec951121db58ce152b3b Mon Sep 17 00:00:00 2001
From: marxin <mli...@suse.cz>
Date: Thu, 13 Jul 2017 13:37:47 +0200
Subject: [PATCH] Move static chain and non-local goto init after
NOTE_INSN_FUNCTION_BEG
gcc/ChangeLog:
2017-06-27 Martin Liska <mli...@suse.cz>
PR sanitize/81186
* function.c (expand_function_start): Move static chain and non-local
goto init after NOTE_INSN_FUNCTION_BEG.
* asan.c (asan_emit_stack_protection): Preserve static chain
register if we call __asan_stack_malloc_N.
gcc/testsuite/ChangeLog:
2017-06-27 Martin Liska <mli...@suse.cz>
PR sanitize/81186
* gcc.dg/asan/pr81186.c: New test.
---
gcc/asan.c | 12 ++++++++++++
gcc/function.c | 18 +++++++++---------
gcc/testsuite/gcc.dg/asan/pr81186.c | 18 ++++++++++++++++++
3 files changed, 39 insertions(+), 9 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/asan/pr81186.c
diff --git a/gcc/asan.c b/gcc/asan.c
index 89c2731e8cd..9cc1d21c1fb 100644
--- a/gcc/asan.c
+++ b/gcc/asan.c
@@ -1340,6 +1340,16 @@ asan_emit_stack_protection (rtx base, rtx pbase, unsigned int alignb,
emit_cmp_and_jump_insns (ret, const0_rtx, EQ, NULL_RTX,
VOIDmode, 0, lab,
profile_probability::very_likely ());
+ /* Preserve static chain register in order to not have it clobbered in
+ __asan_stack_malloc_N function. */
+ rtx chain = targetm.calls.static_chain (current_function_decl, true);
+ rtx saved_chain;
+ if (chain)
+ {
+ saved_chain = gen_reg_rtx (Pmode);
+ emit_move_insn (saved_chain, chain);
+ }
+
snprintf (buf, sizeof buf, "__asan_stack_malloc_%d",
use_after_return_class);
ret = init_one_libfunc (buf);
@@ -1347,6 +1357,8 @@ asan_emit_stack_protection (rtx base, rtx pbase, unsigned int alignb,
GEN_INT (asan_frame_size
+ base_align_bias),
TYPE_MODE (pointer_sized_int_node));
+ if (chain)
+ emit_move_insn (chain, saved_chain);
/* __asan_stack_malloc_[n] returns a pointer to fake stack if succeeded
and NULL otherwise. Check RET value is NULL here and jump over the
BASE reassignment in this case. Otherwise, reassign BASE to RET. */
diff --git a/gcc/function.c b/gcc/function.c
index f625489205b..5e8a56099a5 100644
--- a/gcc/function.c
+++ b/gcc/function.c
@@ -5220,6 +5220,14 @@ expand_function_start (tree subr)
In some cases this requires emitting insns. */
assign_parms (subr);
+ /* The following was moved from init_function_start.
+ The move is supposed to make sdb output more accurate. */
+ /* Indicate the beginning of the function body,
+ as opposed to parm setup. */
+ rtx_note *b = emit_note (NOTE_INSN_FUNCTION_BEG);
+
+ gcc_assert (NOTE_P (get_last_insn ()));
+
/* If function gets a static chain arg, store it. */
if (cfun->static_chain_decl)
{
@@ -5284,15 +5292,7 @@ expand_function_start (tree subr)
update_nonlocal_goto_save_area ();
}
- /* The following was moved from init_function_start.
- The move is supposed to make sdb output more accurate. */
- /* Indicate the beginning of the function body,
- as opposed to parm setup. */
- emit_note (NOTE_INSN_FUNCTION_BEG);
-
- gcc_assert (NOTE_P (get_last_insn ()));
-
- parm_birth_insn = get_last_insn ();
+ parm_birth_insn = b;
if (crtl->profile)
{
diff --git a/gcc/testsuite/gcc.dg/asan/pr81186.c b/gcc/testsuite/gcc.dg/asan/pr81186.c
new file mode 100644
index 00000000000..7f0f672ca40
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/asan/pr81186.c
@@ -0,0 +1,18 @@
+/* PR sanitizer/81186 */
+/* { dg-do run } */
+
+int
+main ()
+{
+ __label__ l;
+ void f ()
+ {
+ int a[123];
+
+ goto l;
+ }
+
+ f ();
+l:
+ return 0;
+}
--
2.13.2
