diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2026-08-20 09:49:27 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@kernel.org> | 2026-08-20 18:26:42 +0200 |
| commit | d8aa5dd97944a72d4a9e3cc79bb80fcac7d6e829 (patch) | |
| tree | d3f279b0203bf386cc3e41070b39c5d0049fd518 /include/linux | |
| parent | bde0238083647381d4747355c5a19115a3422b96 (diff) | |
futex: Fix might_sleep() warning in futex_pivot_pending()
A younger me put a WARN in might_sleep() to warn about nested sleep loops. This
younger me also build a wait-loop variant that can deal with it. This wait-loop
variant doesn't have all the fancy wrappers, since it isn't used much. It also
lacks wait-bit support.
Add the wait-bit support and use it to fix the nested wait issue.
Fixes: 8e7ff730dd96 ("futex: Fix race in futex_pivot_pending() during private hash resize")
Reported-by: syzbot+350a93852ac854927f45@syzkaller.appspotmail.com
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260820074927.GH1246887@noisy.programming.kicks-ass.net
Closes: https://syzkaller.appspot.com/bug?extid=350a93852ac854927f45
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/wait.h | 1 | ||||
| -rw-r--r-- | include/linux/wait_bit.h | 1 |
2 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/wait.h b/include/linux/wait.h index dce055e6add3..7e215330199c 100644 --- a/include/linux/wait.h +++ b/include/linux/wait.h @@ -1228,6 +1228,7 @@ long prepare_to_wait_event(struct wait_queue_head *wq_head, struct wait_queue_en void finish_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry); long wait_woken(struct wait_queue_entry *wq_entry, unsigned mode, long timeout); int woken_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key); +int woken_wake_bit_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key); int autoremove_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key); #define DEFINE_WAIT_FUNC(name, function) \ diff --git a/include/linux/wait_bit.h b/include/linux/wait_bit.h index ace7379d627d..553d7b23e3ad 100644 --- a/include/linux/wait_bit.h +++ b/include/linux/wait_bit.h @@ -32,6 +32,7 @@ int out_of_line_wait_on_bit_timeout(unsigned long *word, int, wait_bit_action_f int out_of_line_wait_on_bit_lock(unsigned long *word, int, wait_bit_action_f *action, unsigned int mode); struct wait_queue_head *bit_waitqueue(unsigned long *word, int bit); extern void __init wait_bit_init(void); +extern struct wait_bit_key *__var_wake_key(struct wait_queue_entry *wq_entry, void *arg); int wake_bit_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key); |