The function get_user() can sleep while trying to fetch instruction
from user address space and causes the following warning from the
scheduler.
BUG: sleeping function called from invalid context
Though interrupts get enabled back but it happens bit later after
get_user() is called. This change moves enabling these interrupts
earlier covering the function get_user(). While at this, lets check
for kernel mode and crash as this interrupt should not have been
triggered from the kernel context.
Signed-off-by: Anshuman Khandual <khand...@linux.vnet.ibm.com>
---
arch/powerpc/kernel/traps.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 1e48d15..4d5a55e 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1611,6 +1611,13 @@ void facility_unavailable_exception(struct pt_regs *regs)
else
value = mfspr(SPRN_FSCR);
+ /* We should not have taken this interrupt in kernel */
+ BUG_ON(!user_mode(regs));
+
+ /* We restore the interrupt state now */
+ if (!arch_irq_disabled_regs(regs))
+ local_irq_enable();
+
status = value >> 56;
if (status == FSCR_DSCR_LG) {
/*
@@ -1683,10 +1690,6 @@ void facility_unavailable_exception(struct pt_regs *regs)
facility_strings[status])
facility = facility_strings[status];
- /* We restore the interrupt state now */
- if (!arch_irq_disabled_regs(regs))
- local_irq_enable();
-
pr_err_ratelimited("%sFacility '%s' unavailable (%d), exception at
0x%lx, MSR=%lx\n",
hv ? "Hypervisor " : "", facility, status, regs->nip,
regs->msr);
--
2.9.3
