[PATCH v2 0/2] fix reading ESP during coredump

[Nam Cao <namcao@linutronix.de>]

Hi,

In /proc/PID/stat, there is the kstkesp field which is the stack pointer of
a thread. While the thread is active, this field reads zero. But during a
coredump, it should have a valid value.

However, at the moment, kstkesp is zero even during coredump.

The first commit fixes this problem, and the second commit adds a selftest
to detect if this problem appears again in the future.

v2:
  - Change the fix patch to use PF_POSTCOREDUMP [Oleg]

Link to v1:
  https://lore.kernel.org/lkml/cover.1730883229.git.namcao@linutronix.de/

Nam Cao (2):
  fs/proc: do_task_stat: Fix ESP not readable during coredump
  selftests: coredump: Add stackdump test

 fs/proc/array.c                               |   2 +-
 tools/testing/selftests/coredump/Makefile     |   7 +
 tools/testing/selftests/coredump/README.rst   |  50 ++++++
 tools/testing/selftests/coredump/stackdump    |  14 ++
 .../selftests/coredump/stackdump_test.c       | 154 ++++++++++++++++++
 5 files changed, 226 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/coredump/Makefile
 create mode 100644 tools/testing/selftests/coredump/README.rst
 create mode 100755 tools/testing/selftests/coredump/stackdump
 create mode 100644 tools/testing/selftests/coredump/stackdump_test.c

-- 
2.39.5