[PATCH v3 0/7] kallsyms: Prevent invalid access when showing module buildid

[Petr Mladek <pmladek@suse.com>]

This patchset is cleaning up kallsyms code related to module buildid.
It is fixing an invalid access when printing backtraces, see [v1] for
more details:

  + 1st..4th patches are preparatory.

  + 5th and 6th patches are fixing bpf and ftrace related APIs.

  + 7th patch prevents a potential race.


Changes against [v2]:

  + Fixed typos in commit message [Alexei]

  + Added Acks [Alexei]


Changes against [v1]:

  + Added existing Reviewed-by tags.

  + Shuffled patches to update the kallsyms_lookup_buildid() initialization
    code 1st.

  + Initialized also *modname and *modbuildid in kallsyms_lookup_buildid().

  + Renamed __bpf_address_lookup() to bpf_address_lookup() and used it
    in kallsyms_lookup_buildid(). Did this instead of passing @modbuildid
    parameter just to clear it.


[v1] https://lore.kernel.org/r/20251105142319.1139183-1-pmladek@suse.com
[v2] https://lore.kernel.org/r/20251112142003.182062-1-pmladek@suse.com


Petr Mladek (7):
  kallsyms: Clean up @namebuf initialization in
    kallsyms_lookup_buildid()
  kallsyms: Clean up modname and modbuildid initialization in
    kallsyms_lookup_buildid()
  module: Add helper function for reading module_buildid()
  kallsyms: Cleanup code for appending the module buildid
  kallsyms/bpf: Rename __bpf_address_lookup() to bpf_address_lookup()
  kallsyms/ftrace: Set module buildid in ftrace_mod_address_lookup()
  kallsyms: Prevent module removal when printing module name and buildid

 arch/arm64/net/bpf_jit_comp.c   |  2 +-
 arch/powerpc/net/bpf_jit_comp.c |  2 +-
 include/linux/filter.h          | 26 ++----------
 include/linux/ftrace.h          |  6 ++-
 include/linux/module.h          |  9 ++++
 kernel/bpf/core.c               |  4 +-
 kernel/kallsyms.c               | 73 ++++++++++++++++++++++++---------
 kernel/module/kallsyms.c        |  9 +---
 kernel/trace/ftrace.c           |  5 ++-
 9 files changed, 81 insertions(+), 55 deletions(-)

-- 
2.52.0