The patch titled
Subject: fs-epoll-use-a-per-cpu-counter-for-users-watches-count-fix
has been added to the -mm tree. Its filename is
fs-epoll-use-a-per-cpu-counter-for-users-watches-count-fix.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/fs-epoll-use-a-per-cpu-counter-for-users-watches-count-fix.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/fs-epoll-use-a-per-cpu-counter-for-users-watches-count-fix.patch
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------------------------------------------------------
From: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Subject: fs-epoll-use-a-per-cpu-counter-for-users-watches-count-fix
fix build errors in kernel/user.c when CONFIG_EPOLL=n
Also fix typo: "cpunter" -"counter" in a panic message.
[npiggin@xxxxxxxxx: move ifdefs into wrapper functions, slightly improve panic message]
Link: https://lkml.kernel.org/r/1628051945.fens3r99ox.astroid@xxxxxxxxx
Fixes: e75b89477811 ("fs/epoll: use a per-cpu counter for user's watches count")
Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx>
Cc: Mark Brown <broonie@xxxxxxxxxx>
Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/user.c | 25 ++++++++++++++++++++-----
1 file changed, 20 insertions(+), 5 deletions(-)
--- a/kernel/user.c~fs-epoll-use-a-per-cpu-counter-for-users-watches-count-fix
+++ a/kernel/user.c
@@ -129,6 +129,21 @@ static struct user_struct *uid_hash_find
return NULL;
}
+static int user_epoll_alloc(struct user_struct *up)
+{
+#ifdef CONFIG_EPOLL
+ return percpu_counter_init(&up->epoll_watches, 0, GFP_KERNEL);
+#endif
+ return 0;
+}
+
+static void user_epoll_free(struct user_struct *up)
+{
+#ifdef CONFIG_EPOLL
+ percpu_counter_destroy(&up->epoll_watches);
+#endif
+}
+
/* IRQs are disabled and uidhash_lock is held upon function entry.
* IRQ state (as stored in flags) is restored and uidhash_lock released
* upon function exit.
@@ -138,7 +153,7 @@ static void free_user(struct user_struct
{
uid_hash_remove(up);
spin_unlock_irqrestore(&uidhash_lock, flags);
- percpu_counter_destroy(&up->epoll_watches);
+ user_epoll_free(up);
kmem_cache_free(uid_cachep, up);
}
@@ -186,7 +201,7 @@ struct user_struct *alloc_uid(kuid_t uid
new->uid = uid;
refcount_set(&new->__count, 1);
- if (percpu_counter_init(&new->epoll_watches, 0, GFP_KERNEL)) {
+ if (user_epoll_alloc(new)) {
kmem_cache_free(uid_cachep, new);
return NULL;
}
@@ -200,7 +215,7 @@ struct user_struct *alloc_uid(kuid_t uid
spin_lock_irq(&uidhash_lock);
up = uid_hash_find(uid, hashent);
if (up) {
- percpu_counter_destroy(&new->epoll_watches);
+ user_epoll_free(new);
kmem_cache_free(uid_cachep, new);
} else {
uid_hash_insert(new, hashent);
@@ -222,8 +237,8 @@ static int __init uid_cache_init(void)
for(n = 0; n < UIDHASH_SZ; ++n)
INIT_HLIST_HEAD(uidhash_table + n);
- if (percpu_counter_init(&root_user.epoll_watches, 0, GFP_KERNEL))
- panic("percpu cpunter alloc failed");
+ if (user_epoll_alloc(&root_user))
+ panic("root_user epoll percpu counter alloc failed");
/* Insert the root user immediately (init already runs as root) */
spin_lock_irq(&uidhash_lock);
_
Patches currently in -mm which might be from rdunlap@xxxxxxxxxxxxx are
fs-epoll-use-a-per-cpu-counter-for-users-watches-count-fix.patch
scripts-check_extable-fix-typo-in-user-error-message.patch
