Balbir Singh [off-list ref] writes:
quoted hunk ↗ jump to hunk
ISA 3 allows for prevention of instruction fetch and execution
of user mode pages. If such an error occurs, SRR1 bit 35
reports the error. We catch and report the error in do_page_fault()
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
---
arch/powerpc/mm/fault.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index d0b137d..1e7ff7b 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -404,6 +404,10 @@ int do_page_fault(struct pt_regs *regs, unsigned long address,
(cpu_has_feature(CPU_FTR_NOEXECUTE) ||
!(vma->vm_flags & (VM_READ | VM_WRITE))))
goto bad_area;
+
+ if (regs->msr & SRR1_ISI_N_OR_G)
+ goto bad_area;
Can you move that check above the more complicated check. It shouldn't
change anything in practice, but makes it easier to follow the code
because the easy cases can be discarded.
cheers