This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
Re: [PATCH v2] Test errno setup
On 09/03/2017 16:00, Stefan Liebler wrote:
> On 03/08/2017 05:20 PM, Zack Weinberg wrote:
>> On 03/06/2017 09:42 PM, Yury Norov wrote:
>>> On Mon, Mar 06, 2017 at 05:49:19PM -0300, Wainer dos Santos Moschetta wrote:
>>>> LGTM.
>>> Thanks. I don't have the write access to the glibc repo. Could you
>>> (someone else) apply the patch?
>>
>> I have committed the patch.
>>
>> zw
>>
>>
> Hi,
>
> on s390 (31bit), I get the following fails:
> FAIL: misc/test-errno:
> FAIL: mlock: errno is: 12 (Cannot allocate memory) expected: 22 (Invalid argument)
>
> FAIL: posix/test-errno:
> FAIL: mlock: errno is: 12 (Cannot allocate memory) expected: 22 (Invalid argument)
>
> Is it intended, that the same test is run twice?
It is since although they have the same name they are different test
in fact: posix/test-errno.c only uses POSIX defined interfaces while
sysdeps/unix/sysv/linux/test-errno.c check for Linux specific ones.
> Both are compiled with sysdeps/unix/sysv/linux/test-errno.c.
But this indeed the issue and it need to be fixed. I am not sure if
glibc Makefile system can handle test with same name in multiple
paths (and I personally not compiling to actually debug if it is
the case), so I would recommend to just rename Linux specific one
to test-errno-linux.c.
> Or should there two different tests, one compiled
> with posix/test-errno.c
> and the other with sysdeps/unix/sysv/linux/test-errno.c?
>
> Why is the test-errno added to tests in sysdeps/unix/sysv/linux/Makefile with:
> ifeq ($(subdir),misc)
> tests += test-errno
> endif
Afaik it is basically to put the resulting objects/binaries on misc folder
(where usually Linux-only tests are placed).
>
>
>
> Regarding mlock-syscall:
> If the compat mlock syscall is used, it returns 12 (ENOMEM).
> This is also observable if you compile and run the testcase with -m32 on a x86_64 system.
>
>
> I've compiled and run posix/test-errno.c on my s390x system and
> get the following error:
> FAIL: setsockopt: errno is: 22 (Invalid argument) expected: 9 (Bad file descriptor)
>
> sl=0xfdfa9170 before setsockopt syscall.
> The test succeeds if I sl is initialized to zero.
>
POSIX [1] states that mlock should may fail with EINVAL only if
the addr argument is not a multiple of {PAGESIZE}. Linux does
not return this issue, since it aligns the resulting address
to pagesize:
* mm/mlock.c:
666 static __must_check int do_mlock(unsigned long start, size_t len, vm_flags_t flags)
667 {
[...]
676
677 len = PAGE_ALIGN(len + (offset_in_page(start)));
678 start &= PAGE_MASK;
EINVAL is only returned on 'apply_vma_lock_flags':
578 static int apply_vma_lock_flags(unsigned long start, size_t len,
579 vm_flags_t flags)
580 {
[...]
587 end = start + len;
588 if (end < start)
589 return -EINVAL;
But if you runs 32 binaries on 64 bits kernel overflow won't happen.
It is documented in man pages, so I think from kernel side it should
be consistent for 32 bit binaries on 64 bit kernel.
For glibc side, I think we should do something like:
diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index 6b7aa3f..1872cdb 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -43,7 +43,7 @@ sysdep_headers += sys/mount.h sys/acct.h sys/sysctl.h \
bits/mman-linux.h
tests += tst-clone tst-clone2 tst-fanotify tst-personality tst-quota \
- tst-sync_file_range test-errno
+ tst-sync_file_range test-errno-linux
# Generate the list of SYS_* macros for the system calls (__NR_* macros).
diff --git a/sysdeps/unix/sysv/linux/test-errno-linux.c b/sysdeps/unix/sysv/linux/test-errno-linux.c
index ab3735f..c3facd5 100644
--- a/sysdeps/unix/sysv/linux/test-errno-linux.c
+++ b/sysdeps/unix/sysv/linux/test-errno-linux.c
@@ -1,4 +1,5 @@
/* Test that failing system calls do set errno to the correct value.
+ Linux sycalls version.
Copyright (C) 2017 Free Software Foundation, Inc.
This file is part of the GNU C Library.
@@ -90,9 +91,37 @@
fail; \
}))
+#define test_wrp_rv2(rtype, prtype, experr1, experr2, syscall, ...) \
+ (__extension__ ({ \
+ errno = 0xdead; \
+ rtype ret = syscall (__VA_ARGS__); \
+ int err = errno; \
+ int fail; \
+ if (ret == (rtype) -1 && (err == experr1 || err == experr2)) \
+ fail = 0; \
+ else \
+ { \
+ fail = 1; \
+ if (ret != (rtype) -1) \
+ printf ("FAIL: " #syscall ": didn't fail as expected" \
+ " (return "prtype")\n", ret); \
+ else if (err == 0xdead) \
+ puts("FAIL: " #syscall ": didn't update errno\n"); \
+ else if (err != experr1 && err != experr2) \
+ printf ("FAIL: " #syscall \
+ ": errno is: %d (%s) expected: %d (%s) or %d (%s)\n", \
+ err, strerror (err), experr1, strerror (experr1), \
+ experr2, strerror (experr2)); \
+ } \
+ fail; \
+ }))
+
#define test_wrp(experr, syscall, ...) \
test_wrp_rv(int, "%d", experr, syscall, __VA_ARGS__)
+#define test_wrp2(experr1, experr2, syscall, ...) \
+ test_wrp_rv2(int, "%d", experr1, experr2, syscall, __VA_ARGS__)
+
static int
do_test (void)
{
@@ -120,7 +149,12 @@ do_test (void)
fails |= test_wrp (ESRCH, getpgid, -1);
fails |= test_wrp (EINVAL, inotify_add_watch, -1, "/", 0);
fails |= test_wrp (EINVAL, mincore, (void *) -1, 0, vec);
- fails |= test_wrp (EINVAL, mlock, (void *) -1, 1); // different errors
+ /* mlock fails if the result of the addition addr+len was less than addr
+ which indicates final address overflow), however on 32 bits binaries
+ running on 64 bits kernel, internal syscall address check won't result
+ in an invalid address and thus syscalls fails later in vma
+ allocation. */
+ fails |= test_wrp2 (EINVAL, ENOMEM, mlock, (void *) -1, 1);
fails |= test_wrp (EINVAL, nanosleep, &ts, &ts);
fails |= test_wrp (EINVAL, poll, &pollfd, -1, 0);
fails |= test_wrp (ENODEV, quotactl, Q_GETINFO, NULL, -1, (caddr_t) &dqblk);
[1] http://pubs.opengroup.org/onlinepubs/9699919799/
> Bye
> Stefan
>