From: Andrew Bresticker abrestic@rivosinc.com
stable inclusion from stable-v5.10.150 commit d15dca1d46ab6fcdb17914cf780989bdd49db9f5 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I6D0XA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit 7ab72c597356be1e7f0f3d856e54ce78527f43c8 upstream.
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") Reviewed-by: Atish Patra atishp@rivosinc.com Signed-off-by: Andrew Bresticker abrestic@rivosinc.com Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20220915193702.2201018-2-abrestic@rivosinc.com/ Signed-off-by: Palmer Dabbelt palmer@rivosinc.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Jialin Zhang zhangjialin11@huawei.com --- 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 3c8b9e433c67..8f84bbe0ac33 100644 --- a/arch/riscv/mm/fault.c +++ b/arch/riscv/mm/fault.c @@ -167,7 +167,8 @@ 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;