6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jiantao Shan <shanjiantao@xxxxxxxxxxx>
commit efb44ff64c95340b06331fc48634b99efc9dd77c upstream.
As with most architectures, allow handling of read faults in VMAs that
have VM_WRITE but without VM_READ (WRITE implies READ).
Otherwise, reading before writing a write-only memory will error while
reading after writing everything is fine.
BTW, move the VM_EXEC judgement before VM_READ/VM_WRITE to make logic a
little clearer.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 09cfefb7fa70c3af01 ("LoongArch: Add memory management")
Signed-off-by: Jiantao Shan <shanjiantao@xxxxxxxxxxx>
Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/loongarch/mm/fault.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/loongarch/mm/fault.c
+++ b/arch/loongarch/mm/fault.c
@@ -193,10 +193,10 @@ good_area:
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 (!(vma->vm_flags & (VM_READ | VM_WRITE)) && address != exception_era(regs))
+ goto bad_area;
}
/*
