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compat breakage in preadv() and pwritev() 

Fix for a dumb preadv()/pwritev() compat bug - unlike the native
variants, compat_... ones forget to check FMODE_P{READ,WRITE}, so e.g.
on pipe the native preadv() will fail with -ESPIPE and compat one will
act as readv() and succeed.  Not critical, but it's a clear bug with trivial
fix.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
hifive-unleashed-5.1
Al Viro 2011-03-13 01:50:58 -05:00
parent 9179746652
commit 586ce098a2
1 changed files with 6 additions and 2 deletions
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8
fs/compat.c
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@ -1228,7 +1228,9 @@ compat_sys_preadv(unsigned long fd, const struct compat_iovec __user *vec,
file = fget_light(fd, &fput_needed);
if (!file)
return -EBADF;
ret = compat_readv(file, vec, vlen, &pos);
ret = -ESPIPE;
if (file->f_mode & FMODE_PREAD)
ret = compat_readv(file, vec, vlen, &pos);
fput_light(file, fput_needed);
return ret;
}
@ -1285,7 +1287,9 @@ compat_sys_pwritev(unsigned long fd, const struct compat_iovec __user *vec,
file = fget_light(fd, &fput_needed);
if (!file)
return -EBADF;
ret = compat_writev(file, vec, vlen, &pos);
ret = -ESPIPE;
if (file->f_mode & FMODE_PWRITE)
ret = compat_writev(file, vec, vlen, &pos);
fput_light(file, fput_needed);
return ret;
}