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authorAnders Roxell <anders.roxell@linaro.org>2019-01-04 02:28:24 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2019-01-05 00:13:47 +0300
commit634724431607f6f46c495dfef801a1c8b44a96d9 (patch)
tree5bd417facebb70da369d905a4ad1e0ecf1f6e607 /kernel
parent81c9d43f94870be66146739c6e61df40dc17bb64 (diff)
downloadlinux-634724431607f6f46c495dfef801a1c8b44a96d9.tar.xz
kernel/kcov.c: mark write_comp_data() as notrace
Since __sanitizer_cov_trace_const_cmp4 is marked as notrace, the function called from __sanitizer_cov_trace_const_cmp4 shouldn't be traceable either. ftrace_graph_caller() gets called every time func write_comp_data() gets called if it isn't marked 'notrace'. This is the backtrace from gdb: #0 ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:179 #1 0xffffff8010201920 in ftrace_caller () at ../arch/arm64/kernel/entry-ftrace.S:151 #2 0xffffff8010439714 in write_comp_data (type=5, arg1=0, arg2=0, ip=18446743524224276596) at ../kernel/kcov.c:116 #3 0xffffff8010439894 in __sanitizer_cov_trace_const_cmp4 (arg1=<optimized out>, arg2=<optimized out>) at ../kernel/kcov.c:188 #4 0xffffff8010201874 in prepare_ftrace_return (self_addr=18446743524226602768, parent=0xffffff801014b918, frame_pointer=18446743524223531344) at ./include/generated/atomic-instrumented.h:27 #5 0xffffff801020194c in ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:182 Rework so that write_comp_data() that are called from __sanitizer_cov_trace_*_cmp*() are marked as 'notrace'. Commit 903e8ff86753 ("kernel/kcov.c: mark funcs in __sanitizer_cov_trace_pc() as notrace") missed to mark write_comp_data() as 'notrace'. When that patch was created gcc-7 was used. In lib/Kconfig.debug config KCOV_ENABLE_COMPARISONS depends on $(cc-option,-fsanitize-coverage=trace-cmp) That code path isn't hit with gcc-7. However, it were that with gcc-8. Link: http://lkml.kernel.org/r/20181206143011.23719-1-anders.roxell@linaro.org Signed-off-by: Anders Roxell <anders.roxell@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Co-developed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/kcov.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/kcov.c b/kernel/kcov.c
index 97959d7b77e2..c2277dbdbfb1 100644
--- a/kernel/kcov.c
+++ b/kernel/kcov.c
@@ -112,7 +112,7 @@ void notrace __sanitizer_cov_trace_pc(void)
EXPORT_SYMBOL(__sanitizer_cov_trace_pc);
#ifdef CONFIG_KCOV_ENABLE_COMPARISONS
-static void write_comp_data(u64 type, u64 arg1, u64 arg2, u64 ip)
+static void notrace write_comp_data(u64 type, u64 arg1, u64 arg2, u64 ip)
{
struct task_struct *t;
u64 *area;