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@vger.kernel.org # v4.19+ Reviewed-by: Atish Patra atishp@rivosinc.com Signed-off-by: Andrew Bresticker abrestic@rivosinc.com --- 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;