lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

powerpc: Call do_page_fault() with interrupts off

Browse Source 
We currently turn interrupts back to their previous state before
calling do_page_fault(). This can be annoying when debugging as
a bad fault will potentially have lost some processor state before
getting into the debugger.

We also end up calling some generic code with interrupts enabled
such as notify_page_fault() with interrupts enabled, which could
be unexpected.

This changes our code to behave more like other architectures,
and make the assembly entry code call into do_page_faults() with
interrupts disabled. They are conditionally re-enabled from
within do_page_fault() in the same spot x86 does it.

While there, add the might_sleep() test in the case of a successful
trylock of the mmap semaphore, again like x86.

Also fix a bug in the existing assembly where r12 (_MSR) could get
clobbered by C calls (the DTL accounting in the exception common
macro and DISABLE_INTS) in some cases.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---

v2. Add the r12 clobber fix
This commit is contained in:
Benjamin Herrenschmidt
2012-03-07 16:48:45 +11:00
parent 1b70117924
commit a546498f3b
9 changed files with 54 additions and 59 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
arch/powerpc/include/asm/hw_irq.h
View File

@@ -79,6 +79,11 @@ static inline bool arch_irqs_disabled(void)
get_paca()->hard_enabled = 0; \
} while(0)
static inline bool arch_irq_disabled_regs(struct pt_regs *regs)
{
return !regs->softe;
}
#else /* CONFIG_PPC64 */
#define SET_MSR_EE(x) mtmsr(x)
@@ -139,6 +144,11 @@ static inline bool arch_irqs_disabled(void)
#define hard_irq_disable() arch_local_irq_disable()
static inline bool arch_irq_disabled_regs(struct pt_regs *regs)
{
return !(regs->msr & MSR_EE);
}
#endif /* CONFIG_PPC64 */
#define ARCH_IRQ_INIT_FLAGS IRQ_NOREQUEST