[v3,2/2] posix: Implement preadv2 and pwritev2
Commit Message
On 04/06/2017 10:42, H.J. Lu wrote:
> On Sat, Jun 3, 2017 at 8:28 AM, Andreas Schwab <schwab@linux-m68k.org> wrote:
>> On Jun 03 2017, "H.J. Lu" <hjl.tools@gmail.com> wrote:
>>
>>> X32 inherits LO_HI_LONG from x86-64. If we change x86-64
>>> LO_HI_LONG, x32 needs to redefine LO_HI_LONG.
>>
>> Your LO_HI_LONG_FLAGS doesn't work for x32 either.
>>
>
> My patch redefined LO_HI_LONG_FLAGS for x32. Here is an alternate
> patch which defines different LO_HI_LONGs for x86-64 and x32.
>
> Tested on x86-64 and x32.
Thanks for checking out this, I was being fooled by the compiler. Patch
looks ok and I am plan to add this patch to check the above patch for correct
check for invalid flags (which would also have show this issue with LO_HI_LONG
being used on p{read,write}v2).
However it seems to trigger what I think it is a kernel bug on version that
provides p{read,write}v, where preadv2 does fails with EOPNOTSUPP but
pwritev2 does not. For instance, on x86_64-linux-gnu-x32 and i686-linux-gnu
(4.10.0-21-generic/x86_64):
[...]
[pid 1027] preadv2(3, 0xff96d3d0, 1, 0, 0x8 /* RWF_??? */) = -1 EOPNOTSUPP (Operation not supported)
[pid 1027] pwritev2(3, [{"\0\360bVl\206\4\10\0\0\0\0Z=l\367t\372\226\377\214\362`\367\f\0\0\0\0\320\4\10", 32}], 1, 0, 0x8 /* RWF_??? */) = 32
[...]
And on sparcv9-linux-gnu (4.12.0-rc1-sparc64-smp):
[...]
[pid 139846] preadv2(3, [{iov_base=0xffefcd88, iov_len=32}], 1, 0, 0x8 /* RWF_??? */) = -1 EOPNOTSUPP (Operation not supported)
[pid 139846] pwritev2(3, [{iov_base="\377\357\315\300p\1f\314\0\0\0\0\0\0\0\2p\3@\10\0\2B\260p\3+\330\0\1\21\220", iov_len=32}], 1, 0, 0x8 /* RWF_??? */) = 32
[...]
Any idea why kernel ignores invalid flags for pwritev2? Does it invalidate the testcase?
---
* misc/tst-preadvwritev2-common.c: New file.
* misc/tst-preadvwritev2.c (do_test): Add test for invalid flag.
* misc/tst-preadvwritev64v2.c (do_test): Likewise.
---
new file mode 100644
@@ -0,0 +1,46 @@
+/* Common function for preadv2 and pwritev2 tests.
+ Copyright (C) 2017 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <support/check.h>
+
+static void
+do_test_with_invalid_flags (void)
+{
+ int invalid_flag = 0x1;
+#ifdef RWF_HIPRI
+ invalid_flag <<= 1;
+#endif
+#ifdef RWF_DSYNC
+ invalid_flag <<= 1;
+#endif
+#ifdef RWF_SYNC
+ invalid_flag <<= 1;
+#endif
+
+ char buf[32];
+ const struct iovec vec = { .iov_base = buf, .iov_len = sizeof (buf) };
+ if (preadv2 (temp_fd, &vec, 1, 0, invalid_flag) != -1)
+ FAIL_EXIT1 ("preadv2 did not fail with an invalid flag");
+ if (errno != ENOTSUP)
+ FAIL_EXIT1 ("preadv2 failure did not set errno to ENOTSUP (%d)", errno);
+
+ if (pwritev2 (temp_fd, &vec, 1, 0, invalid_flag) != -1)
+ FAIL_EXIT1 ("pwritev2 did not fail with an invalid flag");
+ if (errno != ENOTSUP)
+ FAIL_EXIT1 ("pwritev2 failure did not set errno to ENOTSUP (%d)", errno);
+}
@@ -23,9 +23,12 @@
pwritev2 (__fd, __iov, __iovcnt, __offset, 0)
#include "tst-preadvwritev-common.c"
+#include "tst-preadvwritev2-common.c"
static int
do_test (void)
{
+ do_test_with_invalid_flags ();
+
return do_test_with_offset (0);
}
@@ -25,9 +25,12 @@
pwritev2 (__fd, __iov, __iovcnt, __offset, 0)
#include "tst-preadvwritev-common.c"
+#include "tst-preadvwritev2-common.c"
static int
do_test (void)
{
+ do_test_with_invalid_flags ();
+
return do_test_with_offset (0);
}