diff options
| author | Jakub Jelinek <jakub@redhat.com> | 2018-04-17 22:22:50 +0200 |
|---|---|---|
| committer | Jakub Jelinek <jakub@gcc.gnu.org> | 2018-04-17 22:22:50 +0200 |
| commit | 7504c3bf61443f9255b0a0caf310b5300b59b92d (patch) | |
| tree | 939b6b49b4bfab6a1d9f681469b8ac2b360bfc9f /gcc/builtins.c | |
| parent | aa4ec2cdff98cdeec085fa14af4267a51e4e1052 (diff) | |
| download | gcc-7504c3bf61443f9255b0a0caf310b5300b59b92d.zip gcc-7504c3bf61443f9255b0a0caf310b5300b59b92d.tar.gz gcc-7504c3bf61443f9255b0a0caf310b5300b59b92d.tar.bz2 | |
re PR sanitizer/85230 (asan: false positives in kernel on allocas)
PR sanitizer/85230
* asan.c (handle_builtin_stack_restore): Adjust comment. Emit
__asan_allocas_unpoison call and last_alloca_addr = new_sp before
__builtin_stack_restore rather than after it.
* builtins.c (expand_asan_emit_allocas_unpoison): Pass
arg1 + (virtual_dynamic_stack_rtx - stack_pointer_rtx) as second
argument instead of virtual_dynamic_stack_rtx.
From-SVN: r259446
Diffstat (limited to 'gcc/builtins.c')
| -rw-r--r-- | gcc/builtins.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/gcc/builtins.c b/gcc/builtins.c index 93c617e..a71555e 100644 --- a/gcc/builtins.c +++ b/gcc/builtins.c @@ -5072,18 +5072,24 @@ expand_builtin_alloca (tree exp) return result; } -/* Emit a call to __asan_allocas_unpoison call in EXP. Replace second argument - of the call with virtual_stack_dynamic_rtx because in asan pass we emit a - dummy value into second parameter relying on this function to perform the - change. See motivation for this in comment to handle_builtin_stack_restore - function. */ +/* Emit a call to __asan_allocas_unpoison call in EXP. Add to second argument + of the call virtual_stack_dynamic_rtx - stack_pointer_rtx, which is the + STACK_DYNAMIC_OFFSET value. See motivation for this in comment to + handle_builtin_stack_restore function. */ static rtx expand_asan_emit_allocas_unpoison (tree exp) { tree arg0 = CALL_EXPR_ARG (exp, 0); + tree arg1 = CALL_EXPR_ARG (exp, 1); rtx top = expand_expr (arg0, NULL_RTX, ptr_mode, EXPAND_NORMAL); - rtx bot = convert_memory_address (ptr_mode, virtual_stack_dynamic_rtx); + rtx bot = expand_expr (arg1, NULL_RTX, ptr_mode, EXPAND_NORMAL); + rtx off = expand_simple_binop (Pmode, MINUS, virtual_stack_dynamic_rtx, + stack_pointer_rtx, NULL_RTX, 0, + OPTAB_LIB_WIDEN); + off = convert_modes (ptr_mode, Pmode, off, 0); + bot = expand_simple_binop (ptr_mode, PLUS, bot, off, NULL_RTX, 0, + OPTAB_LIB_WIDEN); rtx ret = init_one_libfunc ("__asan_allocas_unpoison"); ret = emit_library_call_value (ret, NULL_RTX, LCT_NORMAL, ptr_mode, top, ptr_mode, bot, ptr_mode); |