From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lj1-f198.google.com (mail-lj1-f198.google.com [209.85.208.198]) by kanga.kvack.org (Postfix) with ESMTP id C011C8E004D for ; Tue, 11 Dec 2018 05:37:40 -0500 (EST) Received: by mail-lj1-f198.google.com with SMTP id t7-v6so3703374ljg.9 for ; Tue, 11 Dec 2018 02:37:40 -0800 (PST) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id 129sor3613013lfl.19.2018.12.11.02.37.38 for (Google Transport Security); Tue, 11 Dec 2018 02:37:38 -0800 (PST) From: Anders Roxell Subject: [PATCH] kasan: mark kasan_check_(read|write) as 'notrace' Date: Tue, 11 Dec 2018 11:37:33 +0100 Message-Id: <20181211103733.22284-1-anders.roxell@linaro.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: aryabinin@virtuozzo.com Cc: kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, rostedt@goodmis.org, Anders Roxell When option CONFIG_KASAN is enabled toghether with ftrace, function ftrace_graph_caller() gets in to a recursion, via functions kasan_check_read() and kasan_check_write(). Breakpoint 2, ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:179 179 mcount_get_pc x0 // function's pc (gdb) bt #0 ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:179 #1 0xffffff90101406c8 in ftrace_caller () at ../arch/arm64/kernel/entry-ftrace.S:151 #2 0xffffff90106fd084 in kasan_check_write (p=0xffffffc06c170878, size=4) at ../mm/kasan/common.c:105 #3 0xffffff90104a2464 in atomic_add_return (v=, i=) at ./include/generated/atomic-instrumented.h:71 #4 atomic_inc_return (v=) at ./include/generated/atomic-fallback.h:284 #5 trace_graph_entry (trace=0xffffffc03f5ff380) at ../kernel/trace/trace_functions_graph.c:441 #6 0xffffff9010481774 in trace_graph_entry_watchdog (trace=) at ../kernel/trace/trace_selftest.c:741 #7 0xffffff90104a185c in function_graph_enter (ret=, func=, frame_pointer=18446743799894897728, retp=) at ../kernel/trace/trace_functions_graph.c:196 #8 0xffffff9010140628 in prepare_ftrace_return (self_addr=18446743592948977792, parent=0xffffffc03f5ff418, frame_pointer=18446743799894897728) at ../arch/arm64/kernel/ftrace.c:231 #9 0xffffff90101406f4 in ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:182 Backtrace stopped: previous frame identical to this frame (corrupt stack?) (gdb) Rework so that kasan_check_read() and kasan_check_write() is marked with 'notrace'. Signed-off-by: Anders Roxell --- mm/kasan/common.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 03d5d1374ca7..71507d15712b 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -95,13 +95,13 @@ void kasan_disable_current(void) current->kasan_depth--; } -void kasan_check_read(const volatile void *p, unsigned int size) +void notrace kasan_check_read(const volatile void *p, unsigned int size) { check_memory_region((unsigned long)p, size, false, _RET_IP_); } EXPORT_SYMBOL(kasan_check_read); -void kasan_check_write(const volatile void *p, unsigned int size) +void notrace kasan_check_write(const volatile void *p, unsigned int size) { check_memory_region((unsigned long)p, size, true, _RET_IP_); } -- 2.19.2