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@xxxxxxxxxxxxx/ 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
