lkml.org 
[lkml]   [2018]   [Dec]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] vfs: fix preadv64v2 and pwritev64v2 compat syscalls with offset == -1
Date
The preadv2 and pwritev2 syscalls are supposed to emulate the readv and
writev syscalls when offset == -1. Therefore the compat code should
check for offset before calling do_compat_preadv64 and
do_compat_pwritev64. This is the case for the preadv2 and pwritev2
syscalls, but handling of offset == -1 is missing in their 64-bit
equivalent.

This patch fixes that, calling do_compat_readv and do_compat_writev when
offset == -1. This fixes the following glibc tests on x32:
- misc/tst-preadvwritev2
- misc/tst-preadvwritev64v2

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: H.J. Lu <hjl.tools@gmail.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
---
fs/read_write.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/fs/read_write.c b/fs/read_write.c
index 4dae0399c75a..c2dd3737fea2 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1241,6 +1241,9 @@ COMPAT_SYSCALL_DEFINE5(preadv64v2, unsigned long, fd,
const struct compat_iovec __user *,vec,
unsigned long, vlen, loff_t, pos, rwf_t, flags)
{
+ if (pos == -1)
+ return do_compat_readv(fd, vec, vlen, flags);
+
return do_compat_preadv64(fd, vec, vlen, pos, flags);
}
#endif
@@ -1347,6 +1350,9 @@ COMPAT_SYSCALL_DEFINE5(pwritev64v2, unsigned long, fd,
const struct compat_iovec __user *,vec,
unsigned long, vlen, loff_t, pos, rwf_t, flags)
{
+ if (pos == -1)
+ return do_compat_writev(fd, vec, vlen, flags);
+
return do_compat_pwritev64(fd, vec, vlen, pos, flags);
}
#endif
--
2.19.1
\
 
 \ /
  Last update: 2018-12-06 20:28    [W:0.066 / U:2.224 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site