[ Sasha's backport helper bot ]
Hi,
The upstream commit SHA1 provided is correct: 7601df8031fd67310af891897ef6cc0df4209305
WARNING: Author mismatch between patch and upstream commit:
Backport author: Bin Lan <bin.lan.cn@xxxxxxxxxxxxx>
Commit author: Oleg Nesterov <oleg@xxxxxxxxxx>
Status in newer kernel trees:
6.12.y | Present (exact SHA1)
6.11.y | Present (exact SHA1)
6.6.y | Not found
Note: The patch differs from the upstream commit:
---
--- - 2024-11-25 08:56:48.440504041 -0500
+++ /tmp/tmp.DBppGejMK4 2024-11-25 08:56:48.433034088 -0500
@@ -1,3 +1,5 @@
+[ Upstream commit 7601df8031fd67310af891897ef6cc0df4209305 ]
+
lock_task_sighand() can trigger a hard lockup. If NR_CPUS threads call
do_task_stat() at the same time and the process has NR_THREADS, it will
spin with irqs disabled O(NR_CPUS * NR_THREADS) time.
@@ -12,12 +14,14 @@
Cc: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
+[ Resolve minor conflicts ]
+Signed-off-by: Bin Lan <bin.lan.cn@xxxxxxxxxxxxx>
---
- fs/proc/array.c | 58 +++++++++++++++++++++++++++----------------------
- 1 file changed, 32 insertions(+), 26 deletions(-)
+ fs/proc/array.c | 57 +++++++++++++++++++++++++++----------------------
+ 1 file changed, 32 insertions(+), 25 deletions(-)
diff --git a/fs/proc/array.c b/fs/proc/array.c
-index 45ba918638084..34a47fb0c57f2 100644
+index 37b8061d84bb..34a47fb0c57f 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -477,13 +477,13 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
@@ -51,7 +55,7 @@
if (sig->tty) {
struct pid *pgrp = tty_get_pgrp(sig->tty);
tty_pgrp = pid_nr_ns(pgrp, ns);
-@@ -527,27 +523,9 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
+@@ -527,26 +523,9 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
num_threads = get_nr_threads(task);
collect_sigign_sigcatch(task, &sigign, &sigcatch);
@@ -64,13 +68,12 @@
- /* add up live thread stats at the group level */
if (whole) {
-- struct task_struct *t;
--
-- __for_each_thread(sig, t) {
+- struct task_struct *t = task;
+- do {
- min_flt += t->min_flt;
- maj_flt += t->maj_flt;
- gtime += task_gtime(t);
-- }
+- } while_each_thread(task, t);
-
- min_flt += sig->min_flt;
- maj_flt += sig->maj_flt;
@@ -79,7 +82,7 @@
if (sig->flags & (SIGNAL_GROUP_EXIT | SIGNAL_STOP_STOPPED))
exit_code = sig->group_exit_code;
}
-@@ -562,6 +540,34 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
+@@ -561,6 +540,34 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
if (permitted && (!whole || num_threads < 2))
wchan = !task_is_running(task);
@@ -114,3 +117,6 @@
if (whole) {
thread_group_cputime_adjusted(task, &utime, &stime);
} else {
+--
+2.43.0
+
---
Results of testing on various branches:
| Branch | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.6.y | Success | Success |
