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=<optimized out>, i=<optimized out>) at ./include/generated/atomic-instrumented.h:71
#4 atomic_inc_return (v=<optimized out>) 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=<optimized out>) at ../kernel/trace/trace_selftest.c:741
#7 0xffffff90104a185c in function_graph_enter (ret=<optimized out>, func=<optimized out>, frame_pointer=18446743799894897728, retp=<optimized out>) 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 <anders.roxell@xxxxxxxxxx>
---
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
