diff options
| author | Roman Kisel <romank@linux.microsoft.com> | 2024-07-18 11:27:25 -0700 |
|---|---|---|
| committer | Kees Cook <kees@kernel.org> | 2024-08-05 21:29:20 -0700 |
| commit | fb97d2eb542faf19a8725afbd75cbc2518903210 (patch) | |
| tree | 9d5f356907c20e05329e0c7ed9bd59493f0f0340 /kernel/signal.c | |
| parent | c114e9948c2b6a0b400266e59cc656b59e795bca (diff) | |
binfmt_elf, coredump: Log the reason of the failed core dumps
Missing, failed, or corrupted core dumps might impede crash
investigations. To improve reliability of that process and consequently
the programs themselves, one needs to trace the path from producing
a core dumpfile to analyzing it. That path starts from the core dump file
written to the disk by the kernel or to the standard input of a user
mode helper program to which the kernel streams the coredump contents.
There are cases where the kernel will interrupt writing the core out or
produce a truncated/not-well-formed core dump without leaving a note.
Add logging for the core dump collection failure paths to be able to reason
what has gone wrong when the core dump is malformed or missing.
Report the size of the data written to aid in diagnosing the user mode
helper.
Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Link: https://lore.kernel.org/r/20240718182743.1959160-3-romank@linux.microsoft.com
Signed-off-by: Kees Cook <kees@kernel.org>
Diffstat (limited to 'kernel/signal.c')
| -rw-r--r-- | kernel/signal.c | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index 60c737e423a1..8c3417550d71 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2888,6 +2888,8 @@ relock: current->flags |= PF_SIGNALED; if (sig_kernel_coredump(signr)) { + int ret; + if (print_fatal_signals) print_fatal_signal(signr); proc_coredump_connector(current); @@ -2899,7 +2901,24 @@ relock: * first and our do_group_exit call below will use * that value and ignore the one we pass it. */ - do_coredump(&ksig->info); + ret = do_coredump(&ksig->info); + if (ret) + coredump_report_failure("coredump has not been created, error %d", + ret); + else if (!IS_ENABLED(CONFIG_COREDUMP)) { + /* + * Coredumps are not available, can't fail collecting + * the coredump. + * + * Leave a note though that the coredump is going to be + * not created. This is not an error or a warning as disabling + * support in the kernel for coredumps isn't commonplace, and + * the user must've built the kernel with the custom config so + * let them know all works as desired. + */ + coredump_report("no coredump collected as " + "that is disabled in the kernel configuration"); + } } /* |