diff options
| author | Kumar Gala <galak@kernel.crashing.org> | 2007-02-07 01:13:32 -0600 |
|---|---|---|
| committer | Kumar Gala <galak@kernel.crashing.org> | 2007-02-07 01:13:32 -0600 |
| commit | 04903a30a327513b97c1271fc6bc4dad6502d1b8 (patch) | |
| tree | 9761b3fbe0606102ee47d5fed12a50b9c9931280 /arch | |
| parent | 8209003547c4b1006943eac8dc6c1fb6493cafda (diff) | |
[POWERPC] Enable interrupts if we are doing fp math emulation
Anytime we are emulating an instruction we are going to be doing some form of
get_user() to get the instruction image to decode. Since get_user() might
sleep we need to ensure we have interrupts enabled or we might see something
like:
Debug: sleeping function called from invalid context at arch/powerpc/kernel/traps.c:697
in_atomic():0, irqs_disabled():1
Call Trace:
[D6023EB0] [C0007F84] show_stack+0x58/0x174 (unreliable)
[D6023EE0] [C0022C34] __might_sleep+0xbc/0xd0
[D6023EF0] [C000D158] program_check_exception+0x1d8/0x4fc
[D6023F40] [C000E744] ret_from_except_full+0x0/0x4c
--- Exception: 700 at 0x102a7100
LR = 0xdb9ef04
However, we want to ensure that interrupts are disabled when handling a trap
exception that might be used for a kernel breakpoint. This is why ProgramCheck
is marked as EXC_XFER_STD instead of EXC_XFER_EE.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/kernel/traps.c | 29 |
1 files changed, 15 insertions, 14 deletions
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index 6915b91868b..f038caa3c2b 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -739,20 +739,7 @@ void __kprobes program_check_exception(struct pt_regs *regs) extern int do_mathemu(struct pt_regs *regs); /* We can now get here via a FP Unavailable exception if the core - * has no FPU, in that case no reason flags will be set */ -#ifdef CONFIG_MATH_EMULATION - /* (reason & REASON_ILLEGAL) would be the obvious thing here, - * but there seems to be a hardware bug on the 405GP (RevD) - * that means ESR is sometimes set incorrectly - either to - * ESR_DST (!?) or 0. In the process of chasing this with the - * hardware people - not sure if it can happen on any illegal - * instruction or only on FP instructions, whether there is a - * pattern to occurences etc. -dgibson 31/Mar/2003 */ - if (!(reason & REASON_TRAP) && do_mathemu(regs) == 0) { - emulate_single_step(regs); - return; - } -#endif /* CONFIG_MATH_EMULATION */ + * has no FPU, in that case the reason flags will be 0 */ if (reason & REASON_FP) { /* IEEE FP exception */ @@ -778,6 +765,20 @@ void __kprobes program_check_exception(struct pt_regs *regs) local_irq_enable(); +#ifdef CONFIG_MATH_EMULATION + /* (reason & REASON_ILLEGAL) would be the obvious thing here, + * but there seems to be a hardware bug on the 405GP (RevD) + * that means ESR is sometimes set incorrectly - either to + * ESR_DST (!?) or 0. In the process of chasing this with the + * hardware people - not sure if it can happen on any illegal + * instruction or only on FP instructions, whether there is a + * pattern to occurences etc. -dgibson 31/Mar/2003 */ + if (do_mathemu(regs) == 0) { + emulate_single_step(regs); + return; + } +#endif /* CONFIG_MATH_EMULATION */ + /* Try to emulate it if we should. */ if (reason & (REASON_ILLEGAL | REASON_PRIVILEGED)) { switch (emulate_instruction(regs)) { |