[v2,1/2] y2038: linux: Provide __timerfd_gettime64 implementation
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Message ID 20191211165444.18951-1-lukma@denx.de
State New
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Series
  • [v2,1/2] y2038: linux: Provide __timerfd_gettime64 implementation
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Commit Message

Lukasz Majewski Dec. 11, 2019, 4:54 p.m. UTC
This patch replaces auto generated wrapper (as described in
sysdeps/unix/sysv/linux/syscalls.list) for timerfd_gettime with one which
adds extra support for reading 64 bit time values on machines with
__TIMESIZE != 64.
There is no functional change for architectures already supporting 64 bit
time ABI.

This patch is conceptually identical to timer_gettime conversion already
done in sysdeps/unix/sysv/linux/timer_gettime.c.
Please refer to corresponding commit message for detailed description of
introduced functions and the testing procedure.

---
Changes for v2:
- Remove "Contributed by" from the file header
- Remove early check for (fd < 0) in __timerfd_gettime64 as the fd
  correctness check is already done in Linux kernel
- Add single descriptive comment line to provide concise explanation
  of the code
---
 include/time.h                            |  3 ++
 sysdeps/unix/sysv/linux/Makefile          |  3 +-
 sysdeps/unix/sysv/linux/syscalls.list     |  1 -
 sysdeps/unix/sysv/linux/timerfd_gettime.c | 66 +++++++++++++++++++++++
 4 files changed, 71 insertions(+), 2 deletions(-)
 create mode 100644 sysdeps/unix/sysv/linux/timerfd_gettime.c

Comments

Andreas Schwab Dec. 11, 2019, 5:48 p.m. UTC | #1
On Dez 11 2019, Lukasz Majewski wrote:

> diff --git a/sysdeps/unix/sysv/linux/timerfd_gettime.c b/sysdeps/unix/sysv/linux/timerfd_gettime.c
> new file mode 100644
> index 0000000000..18e1fd2991
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/timerfd_gettime.c
> @@ -0,0 +1,66 @@
> +/* timerfd_gettime -- get the timer setting referred to by file descriptor.
> +   Copyright (C) 2019 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; see the file COPYING.LIB.  If
> +   not, see <https://www.gnu.org/licenses/>.  */
> +
> +#include <errno.h>
> +#include <stdlib.h>
> +#include <time.h>
> +#include <sysdep.h>
> +#include <kernel-features.h>
> +
> +int
> +__timerfd_gettime64 (int fd, struct __itimerspec64 *value)
> +{
> +#ifdef __ASSUME_TIME64_SYSCALLS
> +# ifndef __NR_timerfd_gettime64
> +#  define __NR_timerfd_gettime64 __NR_timerfd_gettime
> +# endif
> +  return INLINE_SYSCALL_CALL (timerfd_gettime64, fd, value);
> +#else
> +# ifdef __NR_timerfd_gettime64
> +  int ret = INLINE_SYSCALL_CALL (timerfd_gettime64, fd, value);
> +  if (ret == 0 || errno != ENOSYS)
> +    return ret;
> +# endif
> +  struct itimerspec its32;
> +  int retval = INLINE_SYSCALL_CALL (timerfd_gettime, fd, &its32);
> +  if (retval == 0)
> +    {
> +      value->it_interval = valid_timespec_to_timespec64 (its32.it_interval);
> +      value->it_value = valid_timespec_to_timespec64 (its32.it_value);
> +    }
> +
> +  return retval;
> +#endif
> +}

You need a libc_hidden_def matching the libc_hidden_proto in
include/time.h.

Andreas.
Lukasz Majewski Dec. 11, 2019, 10:35 p.m. UTC | #2
Hi Andreas,

> On Dez 11 2019, Lukasz Majewski wrote:
> 
> > diff --git a/sysdeps/unix/sysv/linux/timerfd_gettime.c
> > b/sysdeps/unix/sysv/linux/timerfd_gettime.c new file mode 100644
> > index 0000000000..18e1fd2991
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/timerfd_gettime.c
> > @@ -0,0 +1,66 @@
> > +/* timerfd_gettime -- get the timer setting referred to by file
> > descriptor.
> > +   Copyright (C) 2019 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; see the file COPYING.LIB.
> >  If
> > +   not, see <https://www.gnu.org/licenses/>.  */
> > +
> > +#include <errno.h>
> > +#include <stdlib.h>
> > +#include <time.h>
> > +#include <sysdep.h>
> > +#include <kernel-features.h>
> > +
> > +int
> > +__timerfd_gettime64 (int fd, struct __itimerspec64 *value)
> > +{
> > +#ifdef __ASSUME_TIME64_SYSCALLS
> > +# ifndef __NR_timerfd_gettime64
> > +#  define __NR_timerfd_gettime64 __NR_timerfd_gettime
> > +# endif
> > +  return INLINE_SYSCALL_CALL (timerfd_gettime64, fd, value);
> > +#else
> > +# ifdef __NR_timerfd_gettime64
> > +  int ret = INLINE_SYSCALL_CALL (timerfd_gettime64, fd, value);
> > +  if (ret == 0 || errno != ENOSYS)
> > +    return ret;
> > +# endif
> > +  struct itimerspec its32;
> > +  int retval = INLINE_SYSCALL_CALL (timerfd_gettime, fd, &its32);
> > +  if (retval == 0)
> > +    {
> > +      value->it_interval = valid_timespec_to_timespec64
> > (its32.it_interval);
> > +      value->it_value = valid_timespec_to_timespec64
> > (its32.it_value);
> > +    }
> > +
> > +  return retval;
> > +#endif
> > +}  

Thank you for your comment.

> 
> You need a libc_hidden_def matching the libc_hidden_proto in
> include/time.h.

I'm a bit confused with this function. Before this patch, it was auto
generated from sysdeps/unix/sysv/linux/syscalls.list description.

From what I've dug (by examining the sysdeps/unix/make-syscalls.sh)  it
was a "strong" symbol without the hidden definition.
Considering the above - there shall NOT be 

+libc_hidden_proto (__timerfd_gettime64); in the first place.

Or do I miss something?


> 
> Andreas.
> 




Best regards,

Lukasz Majewski

--

DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@denx.de
Andreas Schwab Dec. 12, 2019, 3:30 p.m. UTC | #3
On Dez 11 2019, Lukasz Majewski wrote:

> From what I've dug (by examining the sysdeps/unix/make-syscalls.sh)  it
> was a "strong" symbol without the hidden definition.
> Considering the above - there shall NOT be 
>
> +libc_hidden_proto (__timerfd_gettime64); in the first place.
>
> Or do I miss something?

If the function is global and called within the same shlib, it needs to
have a hidden alias.

Andreas.

Patch
diff mbox series

diff --git a/include/time.h b/include/time.h
index e5e8246eac..eb5082b4d7 100644
--- a/include/time.h
+++ b/include/time.h
@@ -181,9 +181,12 @@  libc_hidden_proto (__futimens64);
 
 #if __TIMESIZE == 64
 # define __timer_gettime64 __timer_gettime
+# define __timerfd_gettime64 __timerfd_gettime
 #else
 extern int __timer_gettime64 (timer_t timerid, struct __itimerspec64 *value);
+extern int __timerfd_gettime64 (int fd, struct __itimerspec64 *value);
 libc_hidden_proto (__timer_gettime64);
+libc_hidden_proto (__timerfd_gettime64);
 #endif
 
 #if __TIMESIZE == 64
diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index 07776d28ea..e599fcec23 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -18,7 +18,8 @@  sysdep_routines += adjtimex clone umount umount2 readahead \
 		   setfsuid setfsgid epoll_pwait signalfd \
 		   eventfd eventfd_read eventfd_write prlimit \
 		   personality epoll_wait tee vmsplice splice \
-		   open_by_handle_at mlock2 pkey_mprotect pkey_set pkey_get
+		   open_by_handle_at mlock2 pkey_mprotect pkey_set pkey_get \
+		   timerfd_gettime
 
 CFLAGS-gethostid.c = -fexceptions
 CFLAGS-tee.c = -fexceptions -fasynchronous-unwind-tables
diff --git a/sysdeps/unix/sysv/linux/syscalls.list b/sysdeps/unix/sysv/linux/syscalls.list
index 603e517ca6..385007c662 100644
--- a/sysdeps/unix/sysv/linux/syscalls.list
+++ b/sysdeps/unix/sysv/linux/syscalls.list
@@ -95,7 +95,6 @@  mq_setattr	-	mq_getsetattr	i:ipp	mq_setattr
 
 timerfd_create	EXTRA	timerfd_create	i:ii	timerfd_create
 timerfd_settime	EXTRA	timerfd_settime	i:iipp	timerfd_settime
-timerfd_gettime	EXTRA	timerfd_gettime	i:ip	timerfd_gettime
 
 fanotify_init	EXTRA	fanotify_init	i:ii	fanotify_init
 
diff --git a/sysdeps/unix/sysv/linux/timerfd_gettime.c b/sysdeps/unix/sysv/linux/timerfd_gettime.c
new file mode 100644
index 0000000000..18e1fd2991
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/timerfd_gettime.c
@@ -0,0 +1,66 @@ 
+/* timerfd_gettime -- get the timer setting referred to by file descriptor.
+   Copyright (C) 2019 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; see the file COPYING.LIB.  If
+   not, see <https://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <stdlib.h>
+#include <time.h>
+#include <sysdep.h>
+#include <kernel-features.h>
+
+int
+__timerfd_gettime64 (int fd, struct __itimerspec64 *value)
+{
+#ifdef __ASSUME_TIME64_SYSCALLS
+# ifndef __NR_timerfd_gettime64
+#  define __NR_timerfd_gettime64 __NR_timerfd_gettime
+# endif
+  return INLINE_SYSCALL_CALL (timerfd_gettime64, fd, value);
+#else
+# ifdef __NR_timerfd_gettime64
+  int ret = INLINE_SYSCALL_CALL (timerfd_gettime64, fd, value);
+  if (ret == 0 || errno != ENOSYS)
+    return ret;
+# endif
+  struct itimerspec its32;
+  int retval = INLINE_SYSCALL_CALL (timerfd_gettime, fd, &its32);
+  if (retval == 0)
+    {
+      value->it_interval = valid_timespec_to_timespec64 (its32.it_interval);
+      value->it_value = valid_timespec_to_timespec64 (its32.it_value);
+    }
+
+  return retval;
+#endif
+}
+
+#if __TIMESIZE != 64
+int
+__timerfd_gettime (int fd, struct itimerspec *value)
+{
+  struct __itimerspec64 its64;
+  int retval = __timerfd_gettime64 (fd, &its64);
+  if (retval == 0)
+    {
+      value->it_interval = valid_timespec64_to_timespec (its64.it_interval);
+      value->it_value = valid_timespec64_to_timespec (its64.it_value);
+    }
+
+  return retval;
+}
+#endif
+strong_alias (__timerfd_gettime, timerfd_gettime)