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| author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2012-03-07 05:48:45 (GMT) |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2012-03-08 23:55:08 (GMT) |
| commit | a546498f3bf9aac311c66f965186373aee2ca0b0 (patch) | |
| tree | 86fb9a778aba26df3810acd8e52a921a2d84489b /arch/powerpc/kernel/head_32.S | |
| parent | 1b70117924a4f254840ed70fbe3020d4519a1a9a (diff) | |
| download | linux-a546498f3bf9aac311c66f965186373aee2ca0b0.tar.xz | |
powerpc: Call do_page_fault() with interrupts off
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
Diffstat (limited to 'arch/powerpc/kernel/head_32.S')
| -rw-r--r-- | arch/powerpc/kernel/head_32.S | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S index 0654dba..dc0488b 100644 --- a/arch/powerpc/kernel/head_32.S +++ b/arch/powerpc/kernel/head_32.S @@ -395,7 +395,7 @@ DataAccess: bl hash_page 1: lwz r5,_DSISR(r11) /* get DSISR value */ mfspr r4,SPRN_DAR - EXC_XFER_EE_LITE(0x300, handle_page_fault) + EXC_XFER_LITE(0x300, handle_page_fault) /* Instruction access exception. */ @@ -410,7 +410,7 @@ InstructionAccess: bl hash_page 1: mr r4,r12 mr r5,r9 - EXC_XFER_EE_LITE(0x400, handle_page_fault) + EXC_XFER_LITE(0x400, handle_page_fault) /* External interrupt */ EXCEPTION(0x500, HardwareInterrupt, do_IRQ, EXC_XFER_LITE) |