On Tue, 14 Oct 2025 14:51:49 -0400
Steven Rostedt <[email protected]> wrote:

> From: Steven Rostedt <[email protected]>
> 
> Commit 64cf7d058a00 ("tracing: Have trace_marker use per-cpu data to read
> user space") made an update that fixed both trace_marker and
> trace_marker_raw. But the small difference made to trace_marker_raw had a
> blatant bug in it that any basic testing would have uncovered.
> Unfortunately, the self tests have tests for trace_marker but nothing for
> trace_marker_raw which allowed the bug to get upstream.
> 
> Add basic selftests to test trace_marker_raw so that this doesn't happen
> again.
> 

Looks good to me.

Acked-by: Masami Hiramatsu (Google) <[email protected]>

Thanks!

> Signed-off-by: Steven Rostedt (Google) <[email protected]>
> ---
>  .../ftrace/test.d/00basic/trace_marker_raw.tc | 107 ++++++++++++++++++
>  1 file changed, 107 insertions(+)
>  create mode 100644 
> tools/testing/selftests/ftrace/test.d/00basic/trace_marker_raw.tc
> 
> diff --git 
> a/tools/testing/selftests/ftrace/test.d/00basic/trace_marker_raw.tc 
> b/tools/testing/selftests/ftrace/test.d/00basic/trace_marker_raw.tc
> new file mode 100644
> index 000000000000..7daf7292209e
> --- /dev/null
> +++ b/tools/testing/selftests/ftrace/test.d/00basic/trace_marker_raw.tc
> @@ -0,0 +1,107 @@
> +#!/bin/sh
> +# SPDX-License-Identifier: GPL-2.0
> +# description: Basic tests on writing to trace_marker_raw
> +# requires: trace_marker_raw
> +# flags: instance
> +
> +is_little_endian() {
> +     if lscpu | grep -q 'Little Endian'; then
> +             echo 1;
> +     else
> +             echo 0;
> +     fi
> +}
> +
> +little=`is_little_endian`
> +
> +make_str() {
> +     id=$1
> +     cnt=$2
> +
> +     if [ $little -eq 1 ]; then
> +             val=`printf "\\%03o\\%03o\\%03o\\%03o" \
> +                     $(($id & 0xff)) \
> +                     $((($id >> 8) & 0xff)) \
> +                     $((($id >> 16) & 0xff)) \
> +                     $((($id >> 24) & 0xff))`
> +     else
> +             val=`printf "\\%03o\\%03o\\%03o\\%03o" \
> +                     $((($id >> 24) & 0xff)) \
> +                     $((($id >> 16) & 0xff)) \
> +                     $((($id >> 8) & 0xff)) \
> +                     $(($id & 0xff))`
> +     fi
> +
> +     data=`printf -- 'X%.0s' $(seq $cnt)`
> +
> +     printf "${val}${data}"
> +}
> +
> +write_buffer() {
> +     id=$1
> +     size=$2
> +
> +     # write the string into the raw marker
> +     make_str $id $size > trace_marker_raw
> +}
> +
> +
> +test_multiple_writes() {
> +
> +     # Write a bunch of data where the id is the count of
> +     # data to write
> +     for i in `seq 1 10` `seq 101 110` `seq 1001 1010`; do
> +             write_buffer $i $i
> +     done
> +
> +     # add a little buffer
> +     echo stop > trace_marker
> +
> +     # Check to make sure the number of entries is the id (rounded up by 4)
> +     awk '/.*: # [0-9a-f]* / {
> +                     print;
> +                     cnt = -1;
> +                     for (i = 0; i < NF; i++) {
> +                             # The counter is after the "#" marker
> +                             if ( $i == "#" ) {
> +                                     i++;
> +                                     cnt = strtonum("0x" $i);
> +                                     num = NF - (i + 1);
> +                                     # The number of items is always rounded 
> up by 4
> +                                     cnt2 = int((cnt + 3) / 4) * 4;
> +                                     if (cnt2 != num) {
> +                                             exit 1;
> +                                     }
> +                                     break;
> +                             }
> +                     }
> +             }
> +     // { if (NR > 30) { exit 0; } } ' trace_pipe;
> +}
> +
> +
> +get_buffer_data_size() {
> +     sed -ne 's/^.*data.*size:\([0-9][0-9]*\).*/\1/p' events/header_page
> +}
> +
> +test_buffer() {
> +
> +     # The id must be four bytes, test that 3 bytes fails a write
> +     if echo -n abc > ./trace_marker_raw ; then
> +             echo "Too small of write expected to fail but did not"
> +             exit_fail
> +     fi
> +
> +     size=`get_buffer_data_size`
> +     echo size = $size
> +
> +     # Now add a little more than what it can handle
> +
> +     if write_buffer 0xdeadbeef $size ; then
> +             echo "Too big of write expected to fail but did not"
> +             exit_fail
> +     fi
> +}
> +
> +test_buffer
> +test_multiple_writes
> -- 
> 2.51.0
> 


-- 
Masami Hiramatsu (Google) <[email protected]>

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