Do the check before we re-enable interrupts and clean the code
up a bit.
Signed-off-by: Benjamin Herrenschmidt <b...@kernel.crashing.org>
---
arch/powerpc/mm/fault.c | 27 +++++++++++++--------------
1 file changed, 13 insertions(+), 14 deletions(-)
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 6f3a2437008a..c5859ffd3a96 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -355,24 +355,23 @@ static int __do_page_fault(struct pt_regs *regs, unsigned
long address,
if (unlikely(!is_user && bad_kernel_fault(is_exec, error_code,
address)))
return SIGSEGV;
+ /*
+ * If we're in an interrupt, have no user context or are running
+ * in a region with pagefaults disabled then we must not take the fault
+ */
+ if (unlikely(faulthandler_disabled() || !mm)) {
+ if (is_user)
+ printk_ratelimited(KERN_ERR "Page fault in user mode"
+ " with faulthandler_disabled()=%d"
+ " mm=%=p\n",
+ faulthandler_disabled(), mm);
+ return bad_area_nosemaphore(regs, address);
+ }
+
/* We restore the interrupt state now */
if (!arch_irq_disabled_regs(regs))
local_irq_enable();
- if (faulthandler_disabled() || mm == NULL) {
- if (!is_user)
- return SIGSEGV;
-
- /* faulthandler_disabled() in user mode is really bad,
- as is current->mm == NULL. */
- printk(KERN_EMERG "Page fault in user mode with "
- "faulthandler_disabled() = %d mm = %p\n",
- faulthandler_disabled(), mm);
- printk(KERN_EMERG "NIP = %lx MSR = %lx\n",
- regs->nip, regs->msr);
- die("Weird page fault", regs, SIGSEGV);
- }
-
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
/*
--
2.13.3
