diff mbox

[v3,2/3] y2038: linux: Provide __mq_timedsend_time64 implementation

Message ID 20200304141930.16300-2-lukma@denx.de
State New
Headers show

Commit Message

Lukasz Majewski March 4, 2020, 2:19 p.m. UTC
This patch provides new __mq_timedsend_time64 explicit 64 bit function for
sending messages with absolute timeout.
Moreover, a 32 bit version - __mq_timedsend has been refactored to internally
use __mq_timedsend_time64.

The __mq_timedsend is now supposed to be used on systems still supporting 32
bit time (__TIMESIZE != 64) - hence the necessary conversion to 64 bit struct
__timespec64 from struct timespec.

The new __mq_timedsend_time64 syscall available from Linux 5.1+ has been used,
when applicable.

As this wrapper function is also used internally in the glibc, to e.g. provide
mq_send implementation, an explicit check for abs_timeout being NULL has been
added due to conversions between struct timespec and struct __timespec64.
Before this change the Linux kernel handled this NULL pointer.

Build tests:
- ./src/scripts/build-many-glibcs.py glibcs

Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
  https://github.com/lmajewski/meta-y2038 and run tests:
  https://github.com/lmajewski/y2038-tests/commits/master

Linux kernel, headers and minimal kernel version for glibc build test matrix:
- Linux v5.1 (with mq_timedsend_time64) and glibc built with v5.1 as a
  minimal kernel version (--enable-kernel="5.1.0")
  The __ASSUME_TIME64_SYSCALLS flag defined.

- Linux v5.1 and default minimal kernel version
  The __ASSUME_TIME64_SYSCALLS not defined, but kernel supports
  mq_timedsend_time64 syscall.

- Linux v4.19 (no mq_timedsend_time64 support) with default minimal kernel
  version for contemporary glibc (3.2.0)
  This kernel doesn't support mq_timedsend_time64 syscall, so the fallback to
  mq_timedsend is tested.

Above tests were performed with Y2038 redirection applied as well as without
(so the __TIMESIZE != 64 execution path is checked as well).

---
Changes for v2:
- Fix indentation for __mq_timedsend
- #include <bits/types/struct___timespec64.h> instead of <include/time.h>
---
 include/mqueue.h                       |  9 +++++
 sysdeps/unix/sysv/linux/mq_timedsend.c | 49 ++++++++++++++++++++++++--
 2 files changed, 55 insertions(+), 3 deletions(-)

Comments

Lukasz Majewski March 5, 2020, 9:49 a.m. UTC | #1
Dear All,

> This patch provides new __mq_timedsend_time64 explicit 64 bit
> function for sending messages with absolute timeout.
> Moreover, a 32 bit version - __mq_timedsend has been refactored to
> internally use __mq_timedsend_time64.
> 
> The __mq_timedsend is now supposed to be used on systems still
> supporting 32 bit time (__TIMESIZE != 64) - hence the necessary
> conversion to 64 bit struct __timespec64 from struct timespec.
> 
> The new __mq_timedsend_time64 syscall available from Linux 5.1+ has
> been used, when applicable.
> 
> As this wrapper function is also used internally in the glibc, to
> e.g. provide mq_send implementation, an explicit check for
> abs_timeout being NULL has been added due to conversions between
> struct timespec and struct __timespec64. Before this change the Linux
> kernel handled this NULL pointer.
> 
> Build tests:
> - ./src/scripts/build-many-glibcs.py glibcs
> 
> Run-time tests:
> - Run specific tests on ARM/x86 32bit systems (qemu):
>   https://github.com/lmajewski/meta-y2038 and run tests:
>   https://github.com/lmajewski/y2038-tests/commits/master
> 
> Linux kernel, headers and minimal kernel version for glibc build test
> matrix:
> - Linux v5.1 (with mq_timedsend_time64) and glibc built with v5.1 as a
>   minimal kernel version (--enable-kernel="5.1.0")
>   The __ASSUME_TIME64_SYSCALLS flag defined.
> 
> - Linux v5.1 and default minimal kernel version
>   The __ASSUME_TIME64_SYSCALLS not defined, but kernel supports
>   mq_timedsend_time64 syscall.
> 
> - Linux v4.19 (no mq_timedsend_time64 support) with default minimal
> kernel version for contemporary glibc (3.2.0)
>   This kernel doesn't support mq_timedsend_time64 syscall, so the
> fallback to mq_timedsend is tested.
> 
> Above tests were performed with Y2038 redirection applied as well as
> without (so the __TIMESIZE != 64 execution path is checked as well).
> 

Are there any more comments?

> ---
> Changes for v2:
> - Fix indentation for __mq_timedsend
> - #include <bits/types/struct___timespec64.h> instead of
> <include/time.h> ---
>  include/mqueue.h                       |  9 +++++
>  sysdeps/unix/sysv/linux/mq_timedsend.c | 49
> ++++++++++++++++++++++++-- 2 files changed, 55 insertions(+), 3
> deletions(-)
> 
> diff --git a/include/mqueue.h b/include/mqueue.h
> index 3c66f1711e..81d30dbdf7 100644
> --- a/include/mqueue.h
> +++ b/include/mqueue.h
> @@ -10,4 +10,13 @@ extern __typeof (mq_timedreceive)
> __mq_timedreceive __nonnull ((2, 5)); hidden_proto (__mq_timedreceive)
>  hidden_proto (mq_setattr)
>  # endif
> +#if __TIMESIZE == 64
> +# define __mq_timedsend_time64 __mq_timedsend
> +#else
> +# include <bits/types/struct___timespec64.h>
> +extern int __mq_timedsend_time64 (mqd_t mqdes, const char *msg_ptr,
> +                                  size_t msg_len, unsigned int
> msg_prio,
> +                                  const struct __timespec64
> *abs_timeout); +librt_hidden_proto (__mq_timedsend_time64)
> +#endif
>  #endif
> diff --git a/sysdeps/unix/sysv/linux/mq_timedsend.c
> b/sysdeps/unix/sysv/linux/mq_timedsend.c index 888ec6744a..0d5a860c48
> 100644 --- a/sysdeps/unix/sysv/linux/mq_timedsend.c
> +++ b/sysdeps/unix/sysv/linux/mq_timedsend.c
> @@ -22,12 +22,55 @@
>  /* Add message pointed by MSG_PTR to message queue MQDES, stop
> blocking on full message queue if ABS_TIMEOUT expires.  */
>  int
> -__mq_timedsend (mqd_t mqdes, const char *msg_ptr, size_t msg_len,
> -		unsigned int msg_prio, const struct timespec
> *abs_timeout) +__mq_timedsend_time64 (mqd_t mqdes, const char
> *msg_ptr, size_t msg_len,
> +                       unsigned int msg_prio,
> +                       const struct __timespec64 *abs_timeout)
>  {
> +#ifdef __ASSUME_TIME64_SYSCALLS
> +# ifndef __NR_mq_timedsend_time64
> +#  define __NR_mq_timedsend_time64 __NR_mq_timedsend
> +# endif
> +  return SYSCALL_CANCEL (mq_timedsend_time64, mqdes, msg_ptr,
> msg_len, msg_prio,
> +                         abs_timeout);
> +#else
> +  int ret = SYSCALL_CANCEL (mq_timedsend_time64, mqdes, msg_ptr,
> msg_len,
> +                            msg_prio, abs_timeout);
> +  if (ret == 0 || errno != ENOSYS)
> +    return ret;
> +
> +  struct timespec ts32;
> +  if (abs_timeout)
> +    {
> +      if (! in_time_t_range (abs_timeout->tv_sec))
> +        {
> +          __set_errno (EOVERFLOW);
> +          return -1;
> +        }
> +
> +      ts32 = valid_timespec64_to_timespec (*abs_timeout);
> +    }
> +
>    return SYSCALL_CANCEL (mq_timedsend, mqdes, msg_ptr, msg_len,
> msg_prio,
> -			 abs_timeout);
> +                         abs_timeout ? &ts32 : NULL);
> +#endif
> +}
> +
> +#if __TIMESIZE != 64
> +librt_hidden_def (__mq_timedsend_time64)
> +
> +int
> +__mq_timedsend (mqd_t mqdes, const char *msg_ptr, size_t msg_len,
> +                unsigned int msg_prio, const struct timespec
> *abs_timeout) +{
> +  struct __timespec64 ts64;
> +  if (abs_timeout)
> +    ts64 = valid_timespec_to_timespec64 (*abs_timeout);
> +
> +  return __mq_timedsend_time64 (mqdes, msg_ptr, msg_len, msg_prio,
> +                                abs_timeout ? &ts64 : NULL);
>  }
> +#endif
> +
>  hidden_def (__mq_timedsend)
>  weak_alias (__mq_timedsend, mq_timedsend)
>  hidden_weak (mq_timedsend)




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 March 5, 2020, 4:55 p.m. UTC | #2
On Mär 04 2020, Lukasz Majewski wrote:

> diff --git a/include/mqueue.h b/include/mqueue.h
> index 3c66f1711e..81d30dbdf7 100644
> --- a/include/mqueue.h
> +++ b/include/mqueue.h
> @@ -10,4 +10,13 @@ extern __typeof (mq_timedreceive) __mq_timedreceive __nonnull ((2, 5));
>  hidden_proto (__mq_timedreceive)
>  hidden_proto (mq_setattr)
>  # endif
> +#if __TIMESIZE == 64
> +# define __mq_timedsend_time64 __mq_timedsend
> +#else
> +# include <bits/types/struct___timespec64.h>

I think the header should be included unconditionally.

Andreas.
Lukasz Majewski March 6, 2020, 10:03 a.m. UTC | #3
Hi Andreas,

> On Mär 04 2020, Lukasz Majewski wrote:
> 
> > diff --git a/include/mqueue.h b/include/mqueue.h
> > index 3c66f1711e..81d30dbdf7 100644
> > --- a/include/mqueue.h
> > +++ b/include/mqueue.h
> > @@ -10,4 +10,13 @@ extern __typeof (mq_timedreceive)
> > __mq_timedreceive __nonnull ((2, 5)); hidden_proto
> > (__mq_timedreceive) hidden_proto (mq_setattr)
> >  # endif
> > +#if __TIMESIZE == 64
> > +# define __mq_timedsend_time64 __mq_timedsend
> > +#else
> > +# include <bits/types/struct___timespec64.h>  
> 
> I think the header should be included unconditionally.
> 

The idea behind adding the struct___timespec64.h header only for
"#else" clause was that it is not needed at all when we do have
archs with __TIMESIZE == 64.

IMHO, there is no point in including it when __TIMESIZE == 64.

> 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 March 9, 2020, 9:38 a.m. UTC | #4
On Mär 06 2020, Lukasz Majewski wrote:

> Hi Andreas,
>
>> On Mär 04 2020, Lukasz Majewski wrote:
>> 
>> > diff --git a/include/mqueue.h b/include/mqueue.h
>> > index 3c66f1711e..81d30dbdf7 100644
>> > --- a/include/mqueue.h
>> > +++ b/include/mqueue.h
>> > @@ -10,4 +10,13 @@ extern __typeof (mq_timedreceive)
>> > __mq_timedreceive __nonnull ((2, 5)); hidden_proto
>> > (__mq_timedreceive) hidden_proto (mq_setattr)
>> >  # endif
>> > +#if __TIMESIZE == 64
>> > +# define __mq_timedsend_time64 __mq_timedsend
>> > +#else
>> > +# include <bits/types/struct___timespec64.h>  
>> 
>> I think the header should be included unconditionally.
>> 
>
> The idea behind adding the struct___timespec64.h header only for
> "#else" clause was that it is not needed at all when we do have
> archs with __TIMESIZE == 64.

The problem is that it changes the set of included headers depending on
configuration.

Andreas.
Lukasz Majewski March 9, 2020, 10 a.m. UTC | #5
Hi Andreas,

> On Mär 06 2020, Lukasz Majewski wrote:
> 
> > Hi Andreas,
> >  
> >> On Mär 04 2020, Lukasz Majewski wrote:
> >>   
> >> > diff --git a/include/mqueue.h b/include/mqueue.h
> >> > index 3c66f1711e..81d30dbdf7 100644
> >> > --- a/include/mqueue.h
> >> > +++ b/include/mqueue.h
> >> > @@ -10,4 +10,13 @@ extern __typeof (mq_timedreceive)
> >> > __mq_timedreceive __nonnull ((2, 5)); hidden_proto
> >> > (__mq_timedreceive) hidden_proto (mq_setattr)
> >> >  # endif
> >> > +#if __TIMESIZE == 64
> >> > +# define __mq_timedsend_time64 __mq_timedsend
> >> > +#else
> >> > +# include <bits/types/struct___timespec64.h>    
> >> 
> >> I think the header should be included unconditionally.
> >>   
> >
> > The idea behind adding the struct___timespec64.h header only for
> > "#else" clause was that it is not needed at all when we do have
> > archs with __TIMESIZE == 64.  
> 
> The problem is that it changes the set of included headers depending
> on configuration.

I see - thanks for the clarification.

Just to be 100% sure - is it required for "internal" glibc headers to
have the same set of included headers ?

I mean the struct___timespec64.h is included in ./include/mqueue.h,
which is not exported set of headers (to say in other words - it is
local to built glibc).

> 
> 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 March 9, 2020, 11:23 a.m. UTC | #6
On Mär 09 2020, Lukasz Majewski wrote:

> Just to be 100% sure - is it required for "internal" glibc headers to
> have the same set of included headers ?

It avoids errors due to missing declarations that are only visible in
specific configurations.

Andreas.
Florian Weimer March 10, 2020, 1:10 p.m. UTC | #7
* Lukasz Majewski:

> Just to be 100% sure - is it required for "internal" glibc headers to
> have the same set of included headers ?

There is no absolute requirement.  But header variance does lead to
tree breakage on architectures which are less often in builds.
build-many-glibcs.py has helped to catch these issues much earlier,
but it's still difficult to predict which changes benefit from
pre-commit checking using build-many-glibcs.py.  Adding more header
variance doesn't make that easier.
diff mbox

Patch

diff --git a/include/mqueue.h b/include/mqueue.h
index 3c66f1711e..81d30dbdf7 100644
--- a/include/mqueue.h
+++ b/include/mqueue.h
@@ -10,4 +10,13 @@  extern __typeof (mq_timedreceive) __mq_timedreceive __nonnull ((2, 5));
 hidden_proto (__mq_timedreceive)
 hidden_proto (mq_setattr)
 # endif
+#if __TIMESIZE == 64
+# define __mq_timedsend_time64 __mq_timedsend
+#else
+# include <bits/types/struct___timespec64.h>
+extern int __mq_timedsend_time64 (mqd_t mqdes, const char *msg_ptr,
+                                  size_t msg_len, unsigned int msg_prio,
+                                  const struct __timespec64 *abs_timeout);
+librt_hidden_proto (__mq_timedsend_time64)
+#endif
 #endif
diff --git a/sysdeps/unix/sysv/linux/mq_timedsend.c b/sysdeps/unix/sysv/linux/mq_timedsend.c
index 888ec6744a..0d5a860c48 100644
--- a/sysdeps/unix/sysv/linux/mq_timedsend.c
+++ b/sysdeps/unix/sysv/linux/mq_timedsend.c
@@ -22,12 +22,55 @@ 
 /* Add message pointed by MSG_PTR to message queue MQDES, stop blocking
    on full message queue if ABS_TIMEOUT expires.  */
 int
-__mq_timedsend (mqd_t mqdes, const char *msg_ptr, size_t msg_len,
-		unsigned int msg_prio, const struct timespec *abs_timeout)
+__mq_timedsend_time64 (mqd_t mqdes, const char *msg_ptr, size_t msg_len,
+                       unsigned int msg_prio,
+                       const struct __timespec64 *abs_timeout)
 {
+#ifdef __ASSUME_TIME64_SYSCALLS
+# ifndef __NR_mq_timedsend_time64
+#  define __NR_mq_timedsend_time64 __NR_mq_timedsend
+# endif
+  return SYSCALL_CANCEL (mq_timedsend_time64, mqdes, msg_ptr, msg_len, msg_prio,
+                         abs_timeout);
+#else
+  int ret = SYSCALL_CANCEL (mq_timedsend_time64, mqdes, msg_ptr, msg_len,
+                            msg_prio, abs_timeout);
+  if (ret == 0 || errno != ENOSYS)
+    return ret;
+
+  struct timespec ts32;
+  if (abs_timeout)
+    {
+      if (! in_time_t_range (abs_timeout->tv_sec))
+        {
+          __set_errno (EOVERFLOW);
+          return -1;
+        }
+
+      ts32 = valid_timespec64_to_timespec (*abs_timeout);
+    }
+
   return SYSCALL_CANCEL (mq_timedsend, mqdes, msg_ptr, msg_len, msg_prio,
-			 abs_timeout);
+                         abs_timeout ? &ts32 : NULL);
+#endif
+}
+
+#if __TIMESIZE != 64
+librt_hidden_def (__mq_timedsend_time64)
+
+int
+__mq_timedsend (mqd_t mqdes, const char *msg_ptr, size_t msg_len,
+                unsigned int msg_prio, const struct timespec *abs_timeout)
+{
+  struct __timespec64 ts64;
+  if (abs_timeout)
+    ts64 = valid_timespec_to_timespec64 (*abs_timeout);
+
+  return __mq_timedsend_time64 (mqdes, msg_ptr, msg_len, msg_prio,
+                                abs_timeout ? &ts64 : NULL);
 }
+#endif
+
 hidden_def (__mq_timedsend)
 weak_alias (__mq_timedsend, mq_timedsend)
 hidden_weak (mq_timedsend)