powerpc: Disable interrupts in 64-bit kernel FP and vector faults
If we get a floating point, altivec or vsx unavaible interrupt in
kernel, we trigger a kernel error. There is no point preserving
the interrupt state, in fact, that can even make debugging harder
as the processor state might change (we may even preempt) between
taking the exception and landing in a debugger.
So just make those 3 disable interrupts unconditionally.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
v2: On BookE only disable when hitting the kernel unavailable
path, otherwise it will fail to restore softe as
fast_exception_return doesn't do it.
diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S
index 573613d..3de9993 100644
--- a/arch/powerpc/kernel/exceptions-64e.S
+++ b/arch/powerpc/kernel/exceptions-64e.S
@@ -354,9 +354,9 @@
/* we can probably do a shorter exception entry for that one... */
EXCEPTION_COMMON(0x800, PACA_EXGEN, INTS_KEEP)
bne 1f /* if from user, just load it up */
+ INTS_DISABLE_ALL
bl .save_nvgprs
addi r3,r1,STACK_FRAME_OVERHEAD
- INTS_RESTORE_HARD
bl .kernel_fp_unavailable_exception
BUG_OPCODE
1: ld r12,_MSR(r1)
@@ -391,10 +391,9 @@
/* Auxiliary Processor Unavailable Interrupt */
START_EXCEPTION(ap_unavailable);
NORMAL_EXCEPTION_PROLOG(0xf20, PROLOG_ADDITION_NONE)
- EXCEPTION_COMMON(0xf20, PACA_EXGEN, INTS_KEEP)
- addi r3,r1,STACK_FRAME_OVERHEAD
+ EXCEPTION_COMMON(0xf20, PACA_EXGEN, INTS_DISABLE_ALL)
bl .save_nvgprs
- INTS_RESTORE_HARD
+ addi r3,r1,STACK_FRAME_OVERHEAD
bl .unknown_exception
b .ret_from_except
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index d8ff6d3..0fb42ae 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -762,8 +762,8 @@
EXCEPTION_PROLOG_COMMON(0x800, PACA_EXGEN)
bne 1f /* if from user, just load it up */
bl .save_nvgprs
+ DISABLE_INTS
addi r3,r1,STACK_FRAME_OVERHEAD
- ENABLE_INTS
bl .kernel_fp_unavailable_exception
BUG_OPCODE
1: bl .load_up_fpu
@@ -782,8 +782,8 @@
END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
#endif
bl .save_nvgprs
+ DISABLE_INTS
addi r3,r1,STACK_FRAME_OVERHEAD
- ENABLE_INTS
bl .altivec_unavailable_exception
b .ret_from_except
@@ -798,8 +798,8 @@
END_FTR_SECTION_IFSET(CPU_FTR_VSX)
#endif
bl .save_nvgprs
+ DISABLE_INTS
addi r3,r1,STACK_FRAME_OVERHEAD
- ENABLE_INTS
bl .vsx_unavailable_exception
b .ret_from_except
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 5d40e59..a750409 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -247,6 +247,9 @@
addr, regs->nip, regs->link, code);
}
+ if (!arch_irq_disabled_regs(regs))
+ local_irq_enable();
+
memset(&info, 0, sizeof(info));
info.si_signo = signr;
info.si_code = code;