[PATCH Resend v2 2/3] ARM: mm: Provide is_write_fault()

From: Kefeng Wang
Date: Mon Nov 15 2021 - 08:39:05 EST


The function will check whether the fault is caused by a write access,
it will be called in die_kernel_fault() too in next patch, so put it
before the function of die_kernel_fault().

Acked-by: Marco Elver <elver@xxxxxxxxxx>
Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
---
arch/arm/mm/fault.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index bc8779d54a64..1207ed925039 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -99,6 +99,11 @@ void show_pte(const char *lvl, struct mm_struct *mm, unsigned long addr)
{ }
#endif /* CONFIG_MMU */

+static inline bool is_write_fault(unsigned int fsr)
+{
+ return (fsr & FSR_WRITE) && !(fsr & FSR_CM);
+}
+
static void die_kernel_fault(const char *msg, struct mm_struct *mm,
unsigned long addr, unsigned int fsr,
struct pt_regs *regs)
@@ -261,7 +266,7 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
if (user_mode(regs))
flags |= FAULT_FLAG_USER;

- if ((fsr & FSR_WRITE) && !(fsr & FSR_CM)) {
+ if (is_write_fault(fsr)) {
flags |= FAULT_FLAG_WRITE;
vm_flags = VM_WRITE;
}
--
2.26.2