Merge tag 'mm-nonmm-stable-2024-03-14-09-36' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:

 - Kuan-Wei Chiu has developed the well-named series "lib min_heap: Min
   heap optimizations".

 - Kuan-Wei Chiu has also sped up the library sorting code in the series
   "lib/sort: Optimize the number of swaps and comparisons".

 - Alexey Gladkov has added the ability for code running within an IPC
   namespace to alter its IPC and MQ limits. The series is "Allow to
   change ipc/mq sysctls inside ipc namespace".

 - Geert Uytterhoeven has contributed some dhrystone maintenance work in
   the series "lib: dhry: miscellaneous cleanups".

 - Ryusuke Konishi continues nilfs2 maintenance work in the series

	"nilfs2: eliminate kmap and kmap_atomic calls"
	"nilfs2: fix kernel bug at submit_bh_wbc()"

 - Nathan Chancellor has updated our build tools requirements in the
   series "Bump the minimum supported version of LLVM to 13.0.1".

 - Muhammad Usama Anjum continues with the selftests maintenance work in
   the series "selftests/mm: Improve run_vmtests.sh".

 - Oleg Nesterov has done some maintenance work against the signal code
   in the series "get_signal: minor cleanups and fix".

Plus the usual shower of singleton patches in various parts of the tree.
Please see the individual changelogs for details.

* tag 'mm-nonmm-stable-2024-03-14-09-36' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (77 commits)
  nilfs2: prevent kernel bug at submit_bh_wbc()
  nilfs2: fix failure to detect DAT corruption in btree and direct mappings
  ocfs2: enable ocfs2_listxattr for special files
  ocfs2: remove SLAB_MEM_SPREAD flag usage
  assoc_array: fix the return value in assoc_array_insert_mid_shortcut()
  buildid: use kmap_local_page()
  watchdog/core: remove sysctl handlers from public header
  nilfs2: use div64_ul() instead of do_div()
  mul_u64_u64_div_u64: increase precision by conditionally swapping a and b
  kexec: copy only happens before uchunk goes to zero
  get_signal: don't initialize ksig->info if SIGNAL_GROUP_EXIT/group_exec_task
  get_signal: hide_si_addr_tag_bits: fix the usage of uninitialized ksig
  get_signal: don't abuse ksig->info.si_signo and ksig->sig
  const_structs.checkpatch: add device_type
  Normalise "name (ad@dr)" MODULE_AUTHORs to "name <ad@dr>"
  dyndbg: replace kstrdup() + strchr() with kstrdup_and_replace()
  list: leverage list_is_head() for list_entry_is_head()
  nilfs2: MAINTAINERS: drop unreachable project mirror site
  smp: make __smp_processor_id() 0-argument macro
  fat: fix uninitialized field in nostale filehandles
  ...

1 files changed, 16 insertions, 12 deletions

diff --git a/kernel/signal.c b/kernel/signal.c
index bdca529f0f7b..7bdbcf1b78d0 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2741,12 +2741,15 @@ relock:
 		/* Has this task already been marked for death? */
 		if ((signal->flags & SIGNAL_GROUP_EXIT) ||
 		     signal->group_exec_task) {
-			clear_siginfo(&ksig->info);
-			ksig->info.si_signo = signr = SIGKILL;
+			signr = SIGKILL;
 			sigdelset(&current->pending.signal, SIGKILL);
 			trace_signal_deliver(SIGKILL, SEND_SIG_NOINFO,
-				&sighand->action[SIGKILL - 1]);
+					     &sighand->action[SIGKILL-1]);
 			recalc_sigpending();
+			/*
+			 * implies do_group_exit() or return to PF_USER_WORKER,
+			 * no need to initialize ksig->info/etc.
+			 */
 			goto fatal;
 		}
 
@@ -2856,7 +2859,7 @@ relock:
 				spin_lock_irq(&sighand->siglock);
 			}
 
-			if (likely(do_signal_stop(ksig->info.si_signo))) {
+			if (likely(do_signal_stop(signr))) {
 				/* It released the siglock.  */
 				goto relock;
 			}
@@ -2880,7 +2883,7 @@ relock:
 
 		if (sig_kernel_coredump(signr)) {
 			if (print_fatal_signals)
-				print_fatal_signal(ksig->info.si_signo);
+				print_fatal_signal(signr);
 			proc_coredump_connector(current);
 			/*
 			 * If it was able to dump core, this kills all
@@ -2895,8 +2898,9 @@ relock:
 
 		/*
 		 * PF_USER_WORKER threads will catch and exit on fatal signals
-		 * themselves. They have cleanup that must be performed, so
-		 * we cannot call do_exit() on their behalf.
+		 * themselves. They have cleanup that must be performed, so we
+		 * cannot call do_exit() on their behalf. Note that ksig won't
+		 * be properly initialized, PF_USER_WORKER's shouldn't use it.
 		 */
 		if (current->flags & PF_USER_WORKER)
 			goto out;
@@ -2904,17 +2908,17 @@ relock:
 		/*
 		 * Death signals, no core dump.
 		 */
-		do_group_exit(ksig->info.si_signo);
+		do_group_exit(signr);
 		/* NOTREACHED */
 	}
 	spin_unlock_irq(&sighand->siglock);
-out:
+
 	ksig->sig = signr;
 
-	if (!(ksig->ka.sa.sa_flags & SA_EXPOSE_TAGBITS))
+	if (signr && !(ksig->ka.sa.sa_flags & SA_EXPOSE_TAGBITS))
 		hide_si_addr_tag_bits(ksig);
-
-	return ksig->sig > 0;
+out:
+	return signr > 0;
 }
 
 /**