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authorAurelien Jarno <aurelien@aurel32.net>2018-12-06 22:05:34 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-04-05 23:29:10 +0300
commit24c6f9fdf8569bc5fec860baa9e6f9a1aee31dbf (patch)
tree5565441e92b08f32d5445ca3f00c5eea32147e79
parent97ac96eec621e861bdc5233db3ed2dcf1ba1a408 (diff)
downloadlinux-24c6f9fdf8569bc5fec860baa9e6f9a1aee31dbf.tar.xz
vfs: fix preadv64v2 and pwritev64v2 compat syscalls with offset == -1
[ Upstream commit cc4b1242d7e3b42eed73881fc749944146493e4f ] 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> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--fs/read_write.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/read_write.c b/fs/read_write.c
index 9819f7c6c8c5..6ab67b860159 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1204,6 +1204,9 @@ COMPAT_SYSCALL_DEFINE5(preadv64v2, unsigned long, fd,
const struct compat_iovec __user *,vec,
unsigned long, vlen, loff_t, pos, int, flags)
{
+ if (pos == -1)
+ return do_compat_readv(fd, vec, vlen, flags);
+
return do_compat_preadv64(fd, vec, vlen, pos, flags);
}
#endif
@@ -1310,6 +1313,9 @@ COMPAT_SYSCALL_DEFINE5(pwritev64v2, unsigned long, fd,
const struct compat_iovec __user *,vec,
unsigned long, vlen, loff_t, pos, int, flags)
{
+ if (pos == -1)
+ return do_compat_writev(fd, vec, vlen, flags);
+
return do_compat_pwritev64(fd, vec, vlen, pos, flags);
}
#endif