[PATCH RESEND v6 06/16] arm64/mm: Use helper fault_signal_pending()

From: Peter Xu
Date: Thu Feb 20 2020 - 10:59:36 EST


Let the arm64 fault handling to use the new fault_signal_pending()
helper, by moving the signal handling out of the retry logic.

Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>
---
arch/arm64/mm/fault.c | 19 +++++++------------
1 file changed, 7 insertions(+), 12 deletions(-)

diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 85566d32958f..6f4b69d712b1 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -513,19 +513,14 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
fault = __do_page_fault(mm, addr, mm_flags, vm_flags);
major |= fault & VM_FAULT_MAJOR;

- if (fault & VM_FAULT_RETRY) {
- /*
- * If we need to retry but a fatal signal is pending,
- * handle the signal first. We do not need to release
- * the mmap_sem because it would already be released
- * in __lock_page_or_retry in mm/filemap.c.
- */
- if (fatal_signal_pending(current)) {
- if (!user_mode(regs))
- goto no_context;
- return 0;
- }
+ /* Quick path to respond to signals */
+ if (fault_signal_pending(fault, regs)) {
+ if (!user_mode(regs))
+ goto no_context;
+ return 0;
+ }

+ if (fault & VM_FAULT_RETRY) {
/*
* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk of
* starvation.
--
2.24.1