The patch titled
Subject: coredump: introduce dump_interrupted()
has been added to the -mm tree. Its filename is
coredump-introduce-dump_interrupted.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Oleg Nesterov <oleg@xxxxxxxxxx>
Subject: coredump: introduce dump_interrupted()
By discussion with Mandeep.
Change dump_write(), dump_seek() and do_coredump() to check
signal_pending() and abort if it is true.
We add the new trivial helper, dump_interrupted(), to document that this
probably needs more work and to simplify the potential freezer changes.
Perhaps it will have more callers.
Ideally it should do try_to_freeze() but then we need the unpleasant
changes in dump_write() and wait_for_dump_helpers(). So far we simply
accept the fact that the freezer can truncate a core-dump but at least you
can reliably suspend.
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Acked-by: Mandeep Singh Baines <msb@xxxxxxxxxxxx>
Cc: Neil Horman <nhorman@xxxxxxxxxx>
Cc: "Rafael J. Wysocki" <rjw@xxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/coredump.c | 20 +++++++++++++++++---
1 file changed, 17 insertions(+), 3 deletions(-)
diff -puN fs/coredump.c~coredump-introduce-dump_interrupted fs/coredump.c
--- a/fs/coredump.c~coredump-introduce-dump_interrupted
+++ a/fs/coredump.c
@@ -418,6 +418,17 @@ static void coredump_finish(struct mm_st
mm->core_state = NULL;
}
+static bool dump_interrupted(void)
+{
+ /*
+ * SIGKILL or freezing() interrupt the coredumping. Perhaps we
+ * can do try_to_freeze() and check __fatal_signal_pending(),
+ * but then we need to teach dump_write() to restart and clear
+ * TIF_SIGPENDING.
+ */
+ return signal_pending(current);
+}
+
static void wait_for_dump_helpers(struct file *file)
{
struct pipe_inode_info *pipe;
@@ -636,7 +647,7 @@ void do_coredump(siginfo_t *siginfo)
if (displaced)
put_files_struct(displaced);
- core_dumped = binfmt->core_dump(&cprm);
+ core_dumped = !dump_interrupted() && binfmt->core_dump(&cprm);
if (ispipe && core_pipe_limit)
wait_for_dump_helpers(cprm.file);
@@ -664,7 +675,9 @@ fail:
*/
int dump_write(struct file *file, const void *addr, int nr)
{
- return access_ok(VERIFY_READ, addr, nr) && file->f_op->write(file, addr, nr, &file->f_pos) == nr;
+ return !dump_interrupted() &&
+ access_ok(VERIFY_READ, addr, nr) &&
+ file->f_op->write(file, addr, nr, &file->f_pos) == nr;
}
EXPORT_SYMBOL(dump_write);
@@ -673,7 +686,8 @@ int dump_seek(struct file *file, loff_t
int ret = 1;
if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
- if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
+ if (dump_interrupted() ||
+ file->f_op->llseek(file, off, SEEK_CUR) < 0)
return 0;
} else {
char *buf = (char *)get_zeroed_page(GFP_KERNEL);
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
thinkpad-acpi-kill-hotkey_thread_mutex.patch
lockdep-introduce-lock_acquire_exclusive-shared-helper-macros.patch
lglock-update-lockdep-annotations-to-report-recursive-local-locks.patch
ptrace-add-ability-to-retrieve-signals-without-removing-from-a-queue-v4.patch
selftest-add-a-test-case-for-ptrace_peeksiginfo.patch
coredump-only-sigkill-should-interrupt-the-coredumping-task.patch
coredump-ensure-that-sigkill-always-kills-the-dumping-thread.patch
coredump-sanitize-the-setting-of-signal-group_exit_code.patch
coredump-introduce-dump_interrupted.patch
coredump-factor-out-the-setting-of-pf_dumpcore.patch
coredump-change-wait_for_dump_helpers-to-use-wait_event_interruptible.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
