1 From 3e9ab5c01015b76d0c44ef0a2cb9821dff69746b Mon Sep 17 00:00:00 2001
2 From: Aurelien Jarno <aurelien@aurel32.net>
3 Date: Thu, 6 Dec 2018 20:05:34 +0100
4 Subject: vfs: fix preadv64v2 and pwritev64v2 compat syscalls with offset == -1
6 [ Upstream commit cc4b1242d7e3b42eed73881fc749944146493e4f ]
8 The preadv2 and pwritev2 syscalls are supposed to emulate the readv and
9 writev syscalls when offset == -1. Therefore the compat code should
10 check for offset before calling do_compat_preadv64 and
11 do_compat_pwritev64. This is the case for the preadv2 and pwritev2
12 syscalls, but handling of offset == -1 is missing in their 64-bit
15 This patch fixes that, calling do_compat_readv and do_compat_writev when
16 offset == -1. This fixes the following glibc tests on x32:
17 - misc/tst-preadvwritev2
18 - misc/tst-preadvwritev64v2
20 Cc: Alexander Viro <viro@zeniv.linux.org.uk>
21 Cc: H.J. Lu <hjl.tools@gmail.com>
22 Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
23 Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
24 Signed-off-by: Sasha Levin <sashal@kernel.org>
26 fs/read_write.c | 6 ++++++
27 1 file changed, 6 insertions(+)
29 diff --git a/fs/read_write.c b/fs/read_write.c
30 index 57a00ef895b2..1c3eada2fe25 100644
33 @@ -1235,6 +1235,9 @@ COMPAT_SYSCALL_DEFINE5(preadv64v2, unsigned long, fd,
34 const struct compat_iovec __user *,vec,
35 unsigned long, vlen, loff_t, pos, rwf_t, flags)
38 + return do_compat_readv(fd, vec, vlen, flags);
40 return do_compat_preadv64(fd, vec, vlen, pos, flags);
43 @@ -1341,6 +1344,9 @@ COMPAT_SYSCALL_DEFINE5(pwritev64v2, unsigned long, fd,
44 const struct compat_iovec __user *,vec,
45 unsigned long, vlen, loff_t, pos, rwf_t, flags)
48 + return do_compat_writev(fd, vec, vlen, flags);
50 return do_compat_pwritev64(fd, vec, vlen, pos, flags);