linux-stable/include/linux/irqflags.h
Sebastian Andrzej Siewior 73d20564e0 hrtimer: Don't dereference the hrtimer pointer after the callback
A hrtimer can be released in its callback, but lockdep_hrtimer_exit()
dereferences the pointer after the callback returns, i.e. a potential use
after free.

Retrieve the context in which the hrtimer expires before the callback is
invoked and use it in lockdep_hrtimer_exit().

Fixes: 40db173965 ("lockdep: Add hrtimer context tracing bits")
Reported-by: syzbot+62c155c276e580cfb606@syzkaller.appspotmail.com
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200331201849.fkp2siy3vcdqvqlz@linutronix.de
2020-04-01 13:20:14 +02:00

222 lines
6.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* include/linux/irqflags.h
*
* IRQ flags tracing: follow the state of the hardirq and softirq flags and
* provide callbacks for transitions between ON and OFF states.
*
* This file gets included from lowlevel asm headers too, to provide
* wrapped versions of the local_irq_*() APIs, based on the
* raw_local_irq_*() macros from the lowlevel headers.
*/
#ifndef _LINUX_TRACE_IRQFLAGS_H
#define _LINUX_TRACE_IRQFLAGS_H
#include <linux/typecheck.h>
#include <asm/irqflags.h>
/* Currently lockdep_softirqs_on/off is used only by lockdep */
#ifdef CONFIG_PROVE_LOCKING
extern void lockdep_softirqs_on(unsigned long ip);
extern void lockdep_softirqs_off(unsigned long ip);
extern void lockdep_hardirqs_on(unsigned long ip);
extern void lockdep_hardirqs_off(unsigned long ip);
#else
static inline void lockdep_softirqs_on(unsigned long ip) { }
static inline void lockdep_softirqs_off(unsigned long ip) { }
static inline void lockdep_hardirqs_on(unsigned long ip) { }
static inline void lockdep_hardirqs_off(unsigned long ip) { }
#endif
#ifdef CONFIG_TRACE_IRQFLAGS
extern void trace_hardirqs_on(void);
extern void trace_hardirqs_off(void);
# define lockdep_hardirq_context(p) ((p)->hardirq_context)
# define lockdep_softirq_context(p) ((p)->softirq_context)
# define lockdep_hardirqs_enabled(p) ((p)->hardirqs_enabled)
# define lockdep_softirqs_enabled(p) ((p)->softirqs_enabled)
# define lockdep_hardirq_enter() \
do { \
if (!current->hardirq_context++) \
current->hardirq_threaded = 0; \
} while (0)
# define lockdep_hardirq_threaded() \
do { \
current->hardirq_threaded = 1; \
} while (0)
# define lockdep_hardirq_exit() \
do { \
current->hardirq_context--; \
} while (0)
# define lockdep_softirq_enter() \
do { \
current->softirq_context++; \
} while (0)
# define lockdep_softirq_exit() \
do { \
current->softirq_context--; \
} while (0)
# define lockdep_hrtimer_enter(__hrtimer) \
({ \
bool __expires_hardirq = true; \
\
if (!__hrtimer->is_hard) { \
current->irq_config = 1; \
__expires_hardirq = false; \
} \
__expires_hardirq; \
})
# define lockdep_hrtimer_exit(__expires_hardirq) \
do { \
if (!__expires_hardirq) \
current->irq_config = 0; \
} while (0)
# define lockdep_posixtimer_enter() \
do { \
current->irq_config = 1; \
} while (0)
# define lockdep_posixtimer_exit() \
do { \
current->irq_config = 0; \
} while (0)
# define lockdep_irq_work_enter(__work) \
do { \
if (!(atomic_read(&__work->flags) & IRQ_WORK_HARD_IRQ))\
current->irq_config = 1; \
} while (0)
# define lockdep_irq_work_exit(__work) \
do { \
if (!(atomic_read(&__work->flags) & IRQ_WORK_HARD_IRQ))\
current->irq_config = 0; \
} while (0)
#else
# define trace_hardirqs_on() do { } while (0)
# define trace_hardirqs_off() do { } while (0)
# define lockdep_hardirq_context(p) 0
# define lockdep_softirq_context(p) 0
# define lockdep_hardirqs_enabled(p) 0
# define lockdep_softirqs_enabled(p) 0
# define lockdep_hardirq_enter() do { } while (0)
# define lockdep_hardirq_threaded() do { } while (0)
# define lockdep_hardirq_exit() do { } while (0)
# define lockdep_softirq_enter() do { } while (0)
# define lockdep_softirq_exit() do { } while (0)
# define lockdep_hrtimer_enter(__hrtimer) false
# define lockdep_hrtimer_exit(__context) do { } while (0)
# define lockdep_posixtimer_enter() do { } while (0)
# define lockdep_posixtimer_exit() do { } while (0)
# define lockdep_irq_work_enter(__work) do { } while (0)
# define lockdep_irq_work_exit(__work) do { } while (0)
#endif
#if defined(CONFIG_IRQSOFF_TRACER) || \
defined(CONFIG_PREEMPT_TRACER)
extern void stop_critical_timings(void);
extern void start_critical_timings(void);
#else
# define stop_critical_timings() do { } while (0)
# define start_critical_timings() do { } while (0)
#endif
/*
* Wrap the arch provided IRQ routines to provide appropriate checks.
*/
#define raw_local_irq_disable() arch_local_irq_disable()
#define raw_local_irq_enable() arch_local_irq_enable()
#define raw_local_irq_save(flags) \
do { \
typecheck(unsigned long, flags); \
flags = arch_local_irq_save(); \
} while (0)
#define raw_local_irq_restore(flags) \
do { \
typecheck(unsigned long, flags); \
arch_local_irq_restore(flags); \
} while (0)
#define raw_local_save_flags(flags) \
do { \
typecheck(unsigned long, flags); \
flags = arch_local_save_flags(); \
} while (0)
#define raw_irqs_disabled_flags(flags) \
({ \
typecheck(unsigned long, flags); \
arch_irqs_disabled_flags(flags); \
})
#define raw_irqs_disabled() (arch_irqs_disabled())
#define raw_safe_halt() arch_safe_halt()
/*
* The local_irq_*() APIs are equal to the raw_local_irq*()
* if !TRACE_IRQFLAGS.
*/
#ifdef CONFIG_TRACE_IRQFLAGS
#define local_irq_enable() \
do { trace_hardirqs_on(); raw_local_irq_enable(); } while (0)
#define local_irq_disable() \
do { raw_local_irq_disable(); trace_hardirqs_off(); } while (0)
#define local_irq_save(flags) \
do { \
raw_local_irq_save(flags); \
trace_hardirqs_off(); \
} while (0)
#define local_irq_restore(flags) \
do { \
if (raw_irqs_disabled_flags(flags)) { \
raw_local_irq_restore(flags); \
trace_hardirqs_off(); \
} else { \
trace_hardirqs_on(); \
raw_local_irq_restore(flags); \
} \
} while (0)
#define safe_halt() \
do { \
trace_hardirqs_on(); \
raw_safe_halt(); \
} while (0)
#else /* !CONFIG_TRACE_IRQFLAGS */
#define local_irq_enable() do { raw_local_irq_enable(); } while (0)
#define local_irq_disable() do { raw_local_irq_disable(); } while (0)
#define local_irq_save(flags) \
do { \
raw_local_irq_save(flags); \
} while (0)
#define local_irq_restore(flags) do { raw_local_irq_restore(flags); } while (0)
#define safe_halt() do { raw_safe_halt(); } while (0)
#endif /* CONFIG_TRACE_IRQFLAGS */
#define local_save_flags(flags) raw_local_save_flags(flags)
/*
* Some architectures don't define arch_irqs_disabled(), so even if either
* definition would be fine we need to use different ones for the time being
* to avoid build issues.
*/
#ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
#define irqs_disabled() \
({ \
unsigned long _flags; \
raw_local_save_flags(_flags); \
raw_irqs_disabled_flags(_flags); \
})
#else /* !CONFIG_TRACE_IRQFLAGS_SUPPORT */
#define irqs_disabled() raw_irqs_disabled()
#endif /* CONFIG_TRACE_IRQFLAGS_SUPPORT */
#define irqs_disabled_flags(flags) raw_irqs_disabled_flags(flags)
#endif