Re: [REGRESSION] mm: process_vm_readv testcase no longer works after compat_prcoess_vm_readv removed
From: Jens Axboe <axboe@kernel.dk>
Date: 2020-10-27 00:02:27
Also in:
io-uring, keyrings, linux-arch, linux-arm-kernel, linux-block, linux-fsdevel, linux-mips, linux-mm, linux-s390, linux-scsi, linuxppc-dev, lkml, netdev, sparclinux
Subsystem:
memory management, memory management - misc, the rest · Maintainers:
Andrew Morton, David Hildenbrand, Linus Torvalds
On 10/26/20 4:55 PM, Kyle Huey wrote:
A test program from the rr[0] test suite, vm_readv_writev[1], no longer works on 5.10-rc1 when compiled as a 32 bit binary and executed on a 64 bit kernel. The first process_vm_readv call (on line 35) now fails with EFAULT. I have bisected this to c3973b401ef2b0b8005f8074a10e96e3ea093823. It should be fairly straightforward to extract the test case from our repository into a standalone program.
Can you check with this applied?
diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c
index fd12da80b6f2..05676722d9cd 100644
--- a/mm/process_vm_access.c
+++ b/mm/process_vm_access.c@@ -273,7 +273,8 @@ static ssize_t process_vm_rw(pid_t pid, return rc; if (!iov_iter_count(&iter)) goto free_iov_l; - iov_r = iovec_from_user(rvec, riovcnt, UIO_FASTIOV, iovstack_r, false); + iov_r = iovec_from_user(rvec, riovcnt, UIO_FASTIOV, iovstack_r, + in_compat_syscall()); if (IS_ERR(iov_r)) { rc = PTR_ERR(iov_r); goto free_iov_l;
--
Jens Axboe