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| author | Ingo Molnar <mingo@kernel.org> | 2015-08-03 11:04:00 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-08-03 11:04:00 +0200 |
| commit | f320ead76a87a9c533f681ecce3bf3241d07c47d (patch) | |
| tree | 76ae437119088b180737670cb99a307e163a1ca0 /arch/x86/kernel/irq.c | |
| parent | 76695af20c015206cffb84b15912be6797d0cca2 (diff) | |
| parent | decd275e62d5eef4b947fab89652fa6afdadf2f2 (diff) | |
| download | linux-f320ead76a87a9c533f681ecce3bf3241d07c47d.tar.bz2 | |
Merge branch 'x86/asm' into locking/core
Upcoming changes to static keys is interacting/conflicting with the following
pending TSC commits in tip:x86/asm:
4ea1636b04db x86/asm/tsc: Rename native_read_tsc() to rdtsc()
...
So merge it into the locking tree to have a smoother resolution.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/irq.c')
| -rw-r--r-- | arch/x86/kernel/irq.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c index c7dfe1be784e..d596eba9586e 100644 --- a/arch/x86/kernel/irq.c +++ b/arch/x86/kernel/irq.c @@ -216,8 +216,23 @@ __visible unsigned int __irq_entry do_IRQ(struct pt_regs *regs) unsigned vector = ~regs->orig_ax; unsigned irq; + /* + * NB: Unlike exception entries, IRQ entries do not reliably + * handle context tracking in the low-level entry code. This is + * because syscall entries execute briefly with IRQs on before + * updating context tracking state, so we can take an IRQ from + * kernel mode with CONTEXT_USER. The low-level entry code only + * updates the context if we came from user mode, so we won't + * switch to CONTEXT_KERNEL. We'll fix that once the syscall + * code is cleaned up enough that we can cleanly defer enabling + * IRQs. + */ + entering_irq(); + /* entering_irq() tells RCU that we're not quiescent. Check it. */ + rcu_lockdep_assert(rcu_is_watching(), "IRQ failed to wake up RCU"); + irq = __this_cpu_read(vector_irq[vector]); if (!handle_irq(irq, regs)) { |