[v6,2/3] y2038: linux: Provide __mq_timedsend_time64 implementation

Message ID 20200331083533.8102-2-lukma@denx.de
State New
Headers show
Series
  • [v6,1/3] y2038: include: Move struct __timespec64 definition to a separate file
Related show

Commit Message

Lukasz Majewski March 31, 2020, 8:35 a.m.
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).

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>


---
Changes for v6:
- Replace implicit check for abs_timeout with an explicit one -
  abs_timeout != NULL
- Reformat the text to avoid long syscall line

Changes for v5:
- Adjust the code for new struct___timespec64.h location

Changes for v4:
- Include <bits/types/struct___timespec64.h> unconditionally, to keep
  consistency across different ports

Changes for v3:
- None

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(-)

-- 
2.20.1

Comments

Sergei Trofimovich via Libc-alpha March 31, 2020, 2:51 p.m. | #1
On 31/03/2020 05:35, Lukasz Majewski wrote:
> 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).

> 

> Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>


Still LGTM, thanks.

As a side note, this might be a candidate for the optimization to avoid
issuing a time64 syscall for every call on non y2038 safe kernels,
as we did for clock_gettime.

> 

> ---

> Changes for v6:

> - Replace implicit check for abs_timeout with an explicit one -

>   abs_timeout != NULL

> - Reformat the text to avoid long syscall line

> 

> Changes for v5:

> - Adjust the code for new struct___timespec64.h location

> 

> Changes for v4:

> - Include <bits/types/struct___timespec64.h> unconditionally, to keep

>   consistency across different ports

> 

> Changes for v3:

> - None

> 

> 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..32e6570529 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

> +#include <struct___timespec64.h>

> +#if __TIMESIZE == 64

> +# define __mq_timedsend_time64 __mq_timedsend

> +#else

> +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..f2a43df300 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 != NULL)

> +    {

> +      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 != NULL ? &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 != NULL)

> +    ts64 = valid_timespec_to_timespec64 (*abs_timeout);

> +

> +  return __mq_timedsend_time64 (mqdes, msg_ptr, msg_len, msg_prio,

> +                                abs_timeout != NULL ? &ts64 : NULL);

>  }

> +#endif

> +

>  hidden_def (__mq_timedsend)

>  weak_alias (__mq_timedsend, mq_timedsend)

>  hidden_weak (mq_timedsend)

>

Patch

diff --git a/include/mqueue.h b/include/mqueue.h
index 3c66f1711e..32e6570529 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
+#include <struct___timespec64.h>
+#if __TIMESIZE == 64
+# define __mq_timedsend_time64 __mq_timedsend
+#else
+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..f2a43df300 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 != NULL)
+    {
+      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 != NULL ? &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 != NULL)
+    ts64 = valid_timespec_to_timespec64 (*abs_timeout);
+
+  return __mq_timedsend_time64 (mqdes, msg_ptr, msg_len, msg_prio,
+                                abs_timeout != NULL ? &ts64 : NULL);
 }
+#endif
+
 hidden_def (__mq_timedsend)
 weak_alias (__mq_timedsend, mq_timedsend)
 hidden_weak (mq_timedsend)