Add access_error() to check whether vma could be accessible or not,
which will be used __do_page_fault() and later vma locked based page
fault.
Signed-off-by: Kefeng Wang <wangkefeng.w...@huawei.com>
---
arch/loongarch/mm/fault.c | 30 ++++++++++++++++++++----------
1 file changed, 20 insertions(+), 10 deletions(-)
diff --git a/arch/loongarch/mm/fault.c b/arch/loongarch/mm/fault.c
index 5d4c742c4bc5..2a45e9f3a485 100644
--- a/arch/loongarch/mm/fault.c
+++ b/arch/loongarch/mm/fault.c
@@ -126,6 +126,22 @@ static void __kprobes do_sigsegv(struct pt_regs *regs,
force_sig_fault(SIGSEGV, si_code, (void __user *)address);
}
+static inline bool access_error(unsigned int flags, struct pt_regs *regs,
+ unsigned long addr, struct vm_area_struct *vma)
+{
+ if (flags & FAULT_FLAG_WRITE) {
+ if (!(vma->vm_flags & VM_WRITE))
+ return true;
+ } else {
+ if (!(vma->vm_flags & VM_READ) && addr != exception_era(regs))
+ return true;
+ if (!(vma->vm_flags & VM_EXEC) && addr == exception_era(regs))
+ return true;
+ }
+
+ return false;
+}
+
/*
* This routine handles page faults. It determines the address,
* and the problem, and then passes it off to one of the appropriate
@@ -169,6 +185,8 @@ static void __kprobes __do_page_fault(struct pt_regs *regs,
if (user_mode(regs))
flags |= FAULT_FLAG_USER;
+ if (write)
+ flags |= FAULT_FLAG_WRITE;
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
retry:
@@ -178,16 +196,8 @@ static void __kprobes __do_page_fault(struct pt_regs *regs,
si_code = SEGV_ACCERR;
- if (write) {
- flags |= FAULT_FLAG_WRITE;
- if (!(vma->vm_flags & VM_WRITE))
- goto bad_area;
- } else {
- if (!(vma->vm_flags & VM_READ) && address !=
exception_era(regs))
- goto bad_area;
- if (!(vma->vm_flags & VM_EXEC) && address ==
exception_era(regs))
- goto bad_area;
- }
+ if (access_error(flags, regs, vma))
+ goto bad_area;
/*
* If for any reason at all we couldn't handle the fault,
--
2.27.0
