[PATCH v3 0/2] libtracecmd: Support changing /proc/kallsyms

[Ilya Leoshkevich <iii@linux.ibm.com>]

v2: https://lore.kernel.org/linux-trace-devel/20250602214154.446881-1-iii@linux.ibm.com/
v2 -> v3: Add a comment and some newlines (Steven).

v1: https://lore.kernel.org/linux-trace-devel/20250416231325.14113-1-iii@linux.ibm.com/
v1 -> v2: Rewrite the size instead of reading the file twice (Steven).
          Turns out exposing do_lseek() is not necessary, since
          everything is in the same C file.

Hi,

this series fixes tracing in presence of frequent BPF or kernel module
loads/unloads. Patch 1 is a small required improvement; patch 2 is the
actual implementation.

The problem can be reproduced like this:

    # while true; do rmmod loop; modprobe loop; done &

    # while trace-cmd record -p function_graph /bin/true; do :; done
      plugin 'function_graph'
    libtracecmd: Invalid argument
      error in size of file '/proc/kallsyms'
    trace-cmd: Invalid argument
      Error creating output file

Best regards,
Ilya

Ilya Leoshkevich (2):
  libtracecmd: Support querying position within a new compressed block
  libtracecmd: Support changing /proc/kallsyms

 lib/trace-cmd/trace-compress.c |  5 ++++-
 lib/trace-cmd/trace-output.c   | 38 +++++++++++++++++++++++++++++++++-
 2 files changed, 41 insertions(+), 2 deletions(-)

-- 
2.50.1