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authorSteven Rostedt (VMware) <rostedt@goodmis.org>2017-08-01 12:01:52 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-08-30 10:21:48 +0200
commit3170d9abc5d0ba56bb1eb4a924fab5b41ee546eb (patch)
treecdb98389dda2ed7ec9b92807548758fc426191a6 /kernel
parent46cd0a3b93a5b4b124f898ca4851888926f00993 (diff)
tracing: Call clear_boot_tracer() at lateinit_sync
commit 4bb0f0e73c8c30917d169c4a0f1ac083690c545b upstream. The clear_boot_tracer function is used to reset the default_bootup_tracer string to prevent it from being accessed after boot, as it originally points to init data. But since clear_boot_tracer() is called via the init_lateinit() call, it races with the initcall for registering the hwlat tracer. If someone adds "ftrace=hwlat" to the kernel command line, depending on how the linker sets up the text, the saved command line may be cleared, and the hwlat tracer never is initialized. Simply have the clear_boot_tracer() be called by initcall_lateinit_sync() as that's for tasks to be called after lateinit. Link: https://bugzilla.kernel.org/show_bug.cgi?id=196551 Fixes: e7c15cd8a ("tracing: Added hardware latency tracer") Reported-by: Zamir SUN <sztsian@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/trace/trace.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 53c308068e39..7379f735a9f4 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -7767,4 +7767,4 @@ __init static int clear_boot_tracer(void)
}
fs_initcall(tracer_init_tracefs);
-late_initcall(clear_boot_tracer);
+late_initcall_sync(clear_boot_tracer);