From: Ondrej Mosnacek omosnace@redhat.com

mainline inclusion from mainline-v6.4-rc1 commit 4f94559f40ad06d627c0fdfc3319cec778a2845b category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IA7NPI

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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This file defines both read and write operations, yet it is being created as read-only. This means that it can't be written to without the CAP_DAC_OVERRIDE capability. Fix the permissions to allow root to write to it without the need to override DAC perms.

Link: https://lore.kernel.org/linux-trace-kernel/20230503140114.3280002-1-omosnace...

Cc: stable@vger.kernel.org Cc: Masami Hiramatsu mhiramat@kernel.org Fixes: 03329f993978 ("tracing: Add tracefs file buffer_percentage") Signed-off-by: Ondrej Mosnacek omosnace@redhat.com Signed-off-by: Steven Rostedt (Google) rostedt@goodmis.org Signed-off-by: Zheng Yejian zhengyejian1@huawei.com --- kernel/trace/trace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 7d25b898f440..4c1f7acf38c4 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -9220,7 +9220,7 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer)

tr->buffer_percent = 50;

- trace_create_file("buffer_percent", TRACE_MODE_READ, d_tracer, + trace_create_file("buffer_percent", TRACE_MODE_WRITE, d_tracer, tr, &buffer_percent_fops);

create_trace_options_dir(tr);