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| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2022-10-26 15:48:30 +0200 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2022-10-28 13:37:23 -0700 |
| commit | dda1c41a07b4a4c3f99b5b28c1e8c485205fe860 (patch) | |
| tree | 5ce360fff16ca56c711caa77ff774f2af0ac647a /fs/exec.c | |
| parent | 1b9c918318476b4441ddd754ee6699b5367bb5ee (diff) | |
| download | lwn-dda1c41a07b4a4c3f99b5b28c1e8c485205fe860.tar.gz lwn-dda1c41a07b4a4c3f99b5b28c1e8c485205fe860.zip | |
mm: multi-gen LRU: move lru_gen_add_mm() out of IRQ-off region
lru_gen_add_mm() has been added within an IRQ-off region in the commit
mentioned below. The other invocations of lru_gen_add_mm() are not within
an IRQ-off region.
The invocation within IRQ-off region is problematic on PREEMPT_RT because
the function is using a spin_lock_t which must not be used within
IRQ-disabled regions.
The other invocations of lru_gen_add_mm() occur while
task_struct::alloc_lock is acquired. Move lru_gen_add_mm() after
interrupts are enabled and before task_unlock().
Link: https://lkml.kernel.org/r/20221026134830.711887-1-bigeasy@linutronix.de
Fixes: bd74fdaea1460 ("mm: multi-gen LRU: support page table walks")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Yu Zhao <yuzhao@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'fs/exec.c')
| -rw-r--r-- | fs/exec.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/exec.c b/fs/exec.c index 349a5da91efe..7ab1f27b805d 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1012,7 +1012,6 @@ static int exec_mmap(struct mm_struct *mm) active_mm = tsk->active_mm; tsk->active_mm = mm; tsk->mm = mm; - lru_gen_add_mm(mm); /* * This prevents preemption while active_mm is being loaded and * it and mm are being updated, which could cause problems for @@ -1025,6 +1024,7 @@ static int exec_mmap(struct mm_struct *mm) activate_mm(active_mm, mm); if (IS_ENABLED(CONFIG_ARCH_WANT_IRQS_OFF_ACTIVATE_MM)) local_irq_enable(); + lru_gen_add_mm(mm); task_unlock(tsk); lru_gen_use_mm(mm); if (old_mm) { |