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charset="utf-8" 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 =3D kzalloc(1, GFP_KERNEL); kfree(s); local_irq_disable(); char c =3D *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. Signed-off-by: Jared Kangas --- mm/kasan/report.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/kasan/report.c b/mm/kasan/report.c index b48c768acc84..c7c0083203cb 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -200,7 +200,7 @@ static inline void fail_non_kasan_kunit_test(void) { } =20 #endif /* CONFIG_KUNIT */ =20 -static DEFINE_SPINLOCK(report_lock); +static DEFINE_RAW_SPINLOCK(report_lock); =20 static void start_report(unsigned long *flags, bool sync) { @@ -211,7 +211,7 @@ static void start_report(unsigned long *flags, bool syn= c) 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("=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D\n"); } =20 @@ -221,7 +221,7 @@ 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("=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D\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) { --=20 2.47.0