diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2020-02-19 09:46:43 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-05-19 15:51:20 +0200 |
| commit | 0d00449c7a28a1514595630735df383dec606812 (patch) | |
| tree | 2983e126ef290b53793ddf46b6df670ad2f7d8a9 /arch/x86/include/asm/traps.h | |
| parent | 5567d11c21a1d508a91a8cb64a819783a0835d9f (diff) | |
x86: Replace ist_enter() with nmi_enter()
A few exceptions (like #DB and #BP) can happen at any location in the code,
this then means that tracers should treat events from these exceptions as
NMI-like. The interrupted context could be holding locks with interrupts
disabled for instance.
Similarly, #MC is an actual NMI-like exception.
All of them use ist_enter() which only concerns itself with RCU, but does
not do any of the other setup that NMIs need. This means things like:
printk()
raw_spin_lock_irq(&logbuf_lock);
<#DB/#BP/#MC>
printk()
raw_spin_lock_irq(&logbuf_lock);
are entirely possible (well, not really since printk tries hard to
play nice, but the concept stands).
So replace ist_enter() with nmi_enter(). Also observe that any nmi_enter()
caller must be both notrace and NOKPROBE, or in the noinstr text section.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Link: https://lkml.kernel.org/r/20200505134101.525508608@linutronix.de
Diffstat (limited to 'arch/x86/include/asm/traps.h')
| -rw-r--r-- | arch/x86/include/asm/traps.h | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h index fe109fc9a1d2..6f6c417e1e46 100644 --- a/arch/x86/include/asm/traps.h +++ b/arch/x86/include/asm/traps.h @@ -118,9 +118,6 @@ void smp_spurious_interrupt(struct pt_regs *regs); void smp_error_interrupt(struct pt_regs *regs); asmlinkage void smp_irq_move_cleanup_interrupt(void); -extern void ist_enter(struct pt_regs *regs); -extern void ist_exit(struct pt_regs *regs); - #ifdef CONFIG_VMAP_STACK void __noreturn handle_stack_overflow(const char *message, struct pt_regs *regs, |