RISC-V does not presently have write-only mappings as that PTE bit pattern
is considered reserved in the privileged spec, so allow handling of read
faults in VMAs that have VM_WRITE without VM_READ in order to be consistent
with other architectures that have similar limitations.
Fixes: 2139619bcad7 ("riscv: mmap with PROT_WRITE but no PROT_READ is invalid")
Cc: <stable@xxxxxxxxxxxxxxx> # v4.19+
Reviewed-by: Atish Patra <atishp@xxxxxxxxxxxx>
Signed-off-by: Andrew Bresticker <abrestic@xxxxxxxxxxxx>
---
new in v3
v3 -> v4: add Fixes tag
---
arch/riscv/mm/fault.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
index f2fbd1400b7c..d86f7cebd4a7 100644
--- a/arch/riscv/mm/fault.c
+++ b/arch/riscv/mm/fault.c
@@ -184,7 +184,8 @@ static inline bool access_error(unsigned long cause, struct vm_area_struct *vma)
}
break;
case EXC_LOAD_PAGE_FAULT:
- if (!(vma->vm_flags & VM_READ)) {
+ /* Write implies read */
+ if (!(vma->vm_flags & (VM_READ | VM_WRITE))) {
return true;
}
break;
--
2.25.1
