diff options
| author | Jared Kangas <jkangas@redhat.com> | 2024-11-19 13:02:34 -0800 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-12-05 19:54:43 -0800 |
| commit | e30a0361b8515d424c73c67de1a43e45a13b8ba2 (patch) | |
| tree | 5d8fbb6330f81ab02d3a426ba03d9775d8d03e5f /mm | |
| parent | 091c1dd2d4df6edd1beebe0e5863d4034ade9572 (diff) | |
| download | lwn-e30a0361b8515d424c73c67de1a43e45a13b8ba2.tar.gz lwn-e30a0361b8515d424c73c67de1a43e45a13b8ba2.zip | |
kasan: make report_lock a raw spinlock
If PREEMPT_RT is enabled, report_lock is a sleeping spinlock and must not
be locked when IRQs are disabled. However, KASAN reports may be triggered
in such contexts. For example:
char *s = kzalloc(1, GFP_KERNEL);
kfree(s);
local_irq_disable();
char c = *s; /* KASAN report here leads to spin_lock() */
local_irq_enable();
Make report_spinlock a raw spinlock to prevent rescheduling when
PREEMPT_RT is enabled.
Link: https://lkml.kernel.org/r/20241119210234.1602529-1-jkangas@redhat.com
Fixes: 342a93247e08 ("locking/spinlock: Provide RT variant header: <linux/spinlock_rt.h>")
Signed-off-by: Jared Kangas <jkangas@redhat.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/kasan/report.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/mm/kasan/report.c b/mm/kasan/report.c index 50fb19ad4388..3fe77a360f1c 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -201,7 +201,7 @@ static inline void fail_non_kasan_kunit_test(void) { } #endif /* CONFIG_KUNIT */ -static DEFINE_SPINLOCK(report_lock); +static DEFINE_RAW_SPINLOCK(report_lock); static void start_report(unsigned long *flags, bool sync) { @@ -212,7 +212,7 @@ static void start_report(unsigned long *flags, bool sync) lockdep_off(); /* Make sure we don't end up in loop. */ report_suppress_start(); - spin_lock_irqsave(&report_lock, *flags); + raw_spin_lock_irqsave(&report_lock, *flags); pr_err("==================================================================\n"); } @@ -222,7 +222,7 @@ static void end_report(unsigned long *flags, const void *addr, bool is_write) trace_error_report_end(ERROR_DETECTOR_KASAN, (unsigned long)addr); pr_err("==================================================================\n"); - spin_unlock_irqrestore(&report_lock, *flags); + raw_spin_unlock_irqrestore(&report_lock, *flags); if (!test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags)) check_panic_on_warn("KASAN"); switch (kasan_arg_fault) { |