The patch titled
Subject: kasan: mark file common so ftrace doesn't trace it
has been added to the -mm tree. Its filename is
kasan-mark-file-common-so-ftrace-doesnt-trace-it.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/kasan-mark-file-common-so-ftrace-doesnt-trace-it.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/kasan-mark-file-common-so-ftrace-doesnt-trace-it.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Anders Roxell <anders.roxell@xxxxxxxxxx>
Subject: kasan: mark file common so ftrace doesn't trace it
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 the kasan implementation isn't traced.
Link: http://lkml.kernel.org/r/20181212183447.15890-1-anders.roxell@xxxxxxxxxx
Signed-off-by: Anders Roxell <anders.roxell@xxxxxxxxxx>
Acked-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Tested-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Acked-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/kasan/Makefile | 1 +
1 file changed, 1 insertion(+)
--- a/mm/kasan/Makefile~kasan-mark-file-common-so-ftrace-doesnt-trace-it
+++ a/mm/kasan/Makefile
@@ -5,6 +5,7 @@ UBSAN_SANITIZE_generic.o := n
UBSAN_SANITIZE_tags.o := n
KCOV_INSTRUMENT := n
+CFLAGS_REMOVE_common.o = -pg
CFLAGS_REMOVE_generic.o = -pg
# Function splitter causes unnecessary splits in __asan_load1/__asan_store1
# see: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63533
_
Patches currently in -mm which might be from anders.roxell@xxxxxxxxxx are
kasan-mark-file-common-so-ftrace-doesnt-trace-it.patch
