[11/18] linux: Only use 64-bit syscall if required for semtimedop
Checks
| Context |
Check |
Description |
| dj/TryBot-apply_patch |
success
|
Patch applied to master at the time it was sent
|
Commit Message
For !__ASSUME_TIME64_SYSCALLS there is no need to issue a 64-bit syscall
if the provided timeout fits in a 32-bit one. The 64-bit usage should
be rare since the timeout is a relative one.
Checked on i686-linux-gnu on a 4.15 kernel and on a 5.11 kernel
(with and without --enable-kernel=5.1) and on x86_64-linux-gnu.
---
sysdeps/unix/sysv/linux/semtimedop.c | 54 ++++++++++++++++------------
sysvipc/Makefile | 9 +++++
sysvipc/test-sysvsem.c | 22 +++++++++---
3 files changed, 57 insertions(+), 28 deletions(-)
Comments
On Thu, 17 Jun 2021 08:50:57 -0300
Adhemerval Zanella <adhemerval.zanella@linaro.org> wrote:
> For !__ASSUME_TIME64_SYSCALLS there is no need to issue a 64-bit
> syscall if the provided timeout fits in a 32-bit one. The 64-bit
> usage should be rare since the timeout is a relative one.
>
> Checked on i686-linux-gnu on a 4.15 kernel and on a 5.11 kernel
> (with and without --enable-kernel=5.1) and on x86_64-linux-gnu.
> ---
> sysdeps/unix/sysv/linux/semtimedop.c | 54
> ++++++++++++++++------------ sysvipc/Makefile |
> 9 +++++ sysvipc/test-sysvsem.c | 22 +++++++++---
> 3 files changed, 57 insertions(+), 28 deletions(-)
>
> diff --git a/sysdeps/unix/sysv/linux/semtimedop.c
> b/sysdeps/unix/sysv/linux/semtimedop.c index b732b6db48..65a8c080f7
> 100644 --- a/sysdeps/unix/sysv/linux/semtimedop.c
> +++ b/sysdeps/unix/sysv/linux/semtimedop.c
> @@ -21,44 +21,52 @@
> #include <sysdep.h>
> #include <errno.h>
>
> +static int
> +semtimedop_syscall (int semid, struct sembuf *sops, size_t nsops,
> + const struct __timespec64 *timeout)
> +{
> +#ifdef __NR_semtimedop_time64
> + return INLINE_SYSCALL_CALL (semtimedop_time64, semid, sops, nsops,
> timeout); +#elif defined __ASSUME_DIRECT_SYSVIPC_SYSCALLS && defined
> __NR_semtimedop
> + return INLINE_SYSCALL_CALL (semtimedop, semid, sops, nsops,
> timeout); +#else
> + return INLINE_SYSCALL_CALL (ipc, IPCOP_semtimedop, semid,
> + SEMTIMEDOP_IPC_ARGS (nsops, sops,
> timeout)); +#endif
> +}
> +
> /* Perform user-defined atomical operation of array of semaphores.
> */ int
> __semtimedop64 (int semid, struct sembuf *sops, size_t nsops,
> const struct __timespec64 *timeout)
> {
> - int r;
> -#if defined __NR_semtimedop_time64
> - r = INLINE_SYSCALL_CALL (semtimedop_time64, semid, sops, nsops,
> timeout); -#elif defined __ASSUME_DIRECT_SYSVIPC_SYSCALLS && defined
> __NR_semtimedop
> - r = INLINE_SYSCALL_CALL (semtimedop, semid, sops, nsops, timeout);
> +#ifdef __ASSUME_TIME64_SYSCALLS
> + return semtimedop_syscall (semid, sops, nsops, timeout);
> #else
> - r = INLINE_SYSCALL_CALL (ipc, IPCOP_semtimedop, semid,
> - SEMTIMEDOP_IPC_ARGS (nsops, sops,
> timeout)); -#endif
> -
> -#ifndef __ASSUME_TIME64_SYSCALLS
> - if (r == 0 || errno != ENOSYS)
> - return r;
> + bool is32bit = timeout != NULL
> + ? in_time_t_range (timeout->tv_sec) : true;
> + if (!is32bit)
> + {
> + int r = semtimedop_syscall (semid, sops, nsops, timeout);
> + if (r == 0 || errno != ENOSYS)
> + return r;
> + __set_errno (EOVERFLOW);
> + return -1;
> + }
>
> struct timespec ts32, *pts32 = NULL;
> if (timeout != NULL)
> {
> - if (! in_time_t_range (timeout->tv_sec))
> - {
> - __set_errno (EINVAL);
> - return -1;
> - }
> ts32 = valid_timespec64_to_timespec (*timeout);
> pts32 = &ts32;
> }
> -# if defined __ASSUME_DIRECT_SYSVIPC_SYSCALLS
> - r = INLINE_SYSCALL_CALL (semtimedop, semid, sops, nsops, pts32);
> +# ifdef __ASSUME_DIRECT_SYSVIPC_SYSCALLS
> + return INLINE_SYSCALL_CALL (semtimedop, semid, sops, nsops, pts32);
> # else
> - r = INLINE_SYSCALL_CALL (ipc, IPCOP_semtimedop, semid,
> - SEMTIMEDOP_IPC_ARGS (nsops, sops, pts32));
> + return INLINE_SYSCALL_CALL (ipc, IPCOP_semtimedop, semid,
> + SEMTIMEDOP_IPC_ARGS (nsops, sops,
> pts32)); # endif
> -#endif /* __ASSUME_TIME64_SYSCALLS */
> - return r;
> +#endif
> }
> #if __TIMESIZE != 64
> libc_hidden_def (__semtimedop64)
> diff --git a/sysvipc/Makefile b/sysvipc/Makefile
> index 86911803b5..d2acb6a70b 100644
> --- a/sysvipc/Makefile
> +++ b/sysvipc/Makefile
> @@ -38,3 +38,12 @@ include ../Rules
>
> CFLAGS-msgrcv.c += -fexceptions -fasynchronous-unwind-tables
> CFLAGS-msgsnd.c += -fexceptions -fasynchronous-unwind-tables
> +
> +ifeq (yes,$(build-shared))
> +librt = $(common-objpfx)rt/librt.so
> +else
> +librt = $(common-objpfx)rt/librt.a
> +endif
> +
> +$(objpfx)test-sysvsem: $(librt)
> +$(objpfx)test-sysvsem-time64: $(librt)
> diff --git a/sysvipc/test-sysvsem.c b/sysvipc/test-sysvsem.c
> index 092418205d..d9034c3dae 100644
> --- a/sysvipc/test-sysvsem.c
> +++ b/sysvipc/test-sysvsem.c
> @@ -16,6 +16,7 @@
> License along with the GNU C Library; if not, see
> <https://www.gnu.org/licenses/>. */
>
> +#include <intprops.h>
> #include <stdio.h>
> #include <stdlib.h>
> #include <errno.h>
> @@ -30,6 +31,8 @@
> #include <support/support.h>
> #include <support/check.h>
> #include <support/temp_file.h>
> +#include <support/xtime.h>
> +#include <support/xsignal.h>
>
> /* These are for the temporary file we generate. */
> static char *name;
> @@ -112,11 +115,20 @@ do_test (void)
> #ifdef _GNU_SOURCE
> /* Set a time for half a second. The semaphore operation should
> timeout with EAGAIN. */
> - struct timespec ts = { 0 /* sec */, 500000000 /* nsec */ };
> - if (semtimedop (semid, &sb2, 1, &ts) != -1
> - || (errno != EAGAIN && errno != ENOSYS))
> - FAIL_EXIT1 ("semtimedop succeed or returned errno !=
> {EAGAIN,ENOSYS} "
> - "(errno=%i)", errno);
> + {
> + struct timespec ts = { 0 /* sec */, 500000000 /* nsec */ };
> + if (semtimedop (semid, &sb2, 1, &ts) != -1
> + || (errno != EAGAIN && errno != ENOSYS))
> + FAIL_EXIT1 ("semtimedop succeed or returned errno !=
> {EAGAIN,ENOSYS} "
> + "(errno=%i)", errno);
> + }
> +
> + {
> + support_create_timer (0, 100000000, false, NULL);
> + struct timespec ts = { TYPE_MAXIMUM (time_t), 0 };
> + TEST_COMPARE (semtimedop (semid, &sb2, 1, &ts), -1);
> + TEST_VERIFY (errno == EINTR || errno == EOVERFLOW);
> + }
> #endif
>
> /* Finally free up the semnaphore resource. */
Reviewed-by: Lukasz Majewski <lukma@denx.de>
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
@@ -21,44 +21,52 @@
#include <sysdep.h>
#include <errno.h>
+static int
+semtimedop_syscall (int semid, struct sembuf *sops, size_t nsops,
+ const struct __timespec64 *timeout)
+{
+#ifdef __NR_semtimedop_time64
+ return INLINE_SYSCALL_CALL (semtimedop_time64, semid, sops, nsops, timeout);
+#elif defined __ASSUME_DIRECT_SYSVIPC_SYSCALLS && defined __NR_semtimedop
+ return INLINE_SYSCALL_CALL (semtimedop, semid, sops, nsops, timeout);
+#else
+ return INLINE_SYSCALL_CALL (ipc, IPCOP_semtimedop, semid,
+ SEMTIMEDOP_IPC_ARGS (nsops, sops, timeout));
+#endif
+}
+
/* Perform user-defined atomical operation of array of semaphores. */
int
__semtimedop64 (int semid, struct sembuf *sops, size_t nsops,
const struct __timespec64 *timeout)
{
- int r;
-#if defined __NR_semtimedop_time64
- r = INLINE_SYSCALL_CALL (semtimedop_time64, semid, sops, nsops, timeout);
-#elif defined __ASSUME_DIRECT_SYSVIPC_SYSCALLS && defined __NR_semtimedop
- r = INLINE_SYSCALL_CALL (semtimedop, semid, sops, nsops, timeout);
+#ifdef __ASSUME_TIME64_SYSCALLS
+ return semtimedop_syscall (semid, sops, nsops, timeout);
#else
- r = INLINE_SYSCALL_CALL (ipc, IPCOP_semtimedop, semid,
- SEMTIMEDOP_IPC_ARGS (nsops, sops, timeout));
-#endif
-
-#ifndef __ASSUME_TIME64_SYSCALLS
- if (r == 0 || errno != ENOSYS)
- return r;
+ bool is32bit = timeout != NULL
+ ? in_time_t_range (timeout->tv_sec) : true;
+ if (!is32bit)
+ {
+ int r = semtimedop_syscall (semid, sops, nsops, timeout);
+ if (r == 0 || errno != ENOSYS)
+ return r;
+ __set_errno (EOVERFLOW);
+ return -1;
+ }
struct timespec ts32, *pts32 = NULL;
if (timeout != NULL)
{
- if (! in_time_t_range (timeout->tv_sec))
- {
- __set_errno (EINVAL);
- return -1;
- }
ts32 = valid_timespec64_to_timespec (*timeout);
pts32 = &ts32;
}
-# if defined __ASSUME_DIRECT_SYSVIPC_SYSCALLS
- r = INLINE_SYSCALL_CALL (semtimedop, semid, sops, nsops, pts32);
+# ifdef __ASSUME_DIRECT_SYSVIPC_SYSCALLS
+ return INLINE_SYSCALL_CALL (semtimedop, semid, sops, nsops, pts32);
# else
- r = INLINE_SYSCALL_CALL (ipc, IPCOP_semtimedop, semid,
- SEMTIMEDOP_IPC_ARGS (nsops, sops, pts32));
+ return INLINE_SYSCALL_CALL (ipc, IPCOP_semtimedop, semid,
+ SEMTIMEDOP_IPC_ARGS (nsops, sops, pts32));
# endif
-#endif /* __ASSUME_TIME64_SYSCALLS */
- return r;
+#endif
}
#if __TIMESIZE != 64
libc_hidden_def (__semtimedop64)
@@ -38,3 +38,12 @@ include ../Rules
CFLAGS-msgrcv.c += -fexceptions -fasynchronous-unwind-tables
CFLAGS-msgsnd.c += -fexceptions -fasynchronous-unwind-tables
+
+ifeq (yes,$(build-shared))
+librt = $(common-objpfx)rt/librt.so
+else
+librt = $(common-objpfx)rt/librt.a
+endif
+
+$(objpfx)test-sysvsem: $(librt)
+$(objpfx)test-sysvsem-time64: $(librt)
@@ -16,6 +16,7 @@
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
+#include <intprops.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
@@ -30,6 +31,8 @@
#include <support/support.h>
#include <support/check.h>
#include <support/temp_file.h>
+#include <support/xtime.h>
+#include <support/xsignal.h>
/* These are for the temporary file we generate. */
static char *name;
@@ -112,11 +115,20 @@ do_test (void)
#ifdef _GNU_SOURCE
/* Set a time for half a second. The semaphore operation should timeout
with EAGAIN. */
- struct timespec ts = { 0 /* sec */, 500000000 /* nsec */ };
- if (semtimedop (semid, &sb2, 1, &ts) != -1
- || (errno != EAGAIN && errno != ENOSYS))
- FAIL_EXIT1 ("semtimedop succeed or returned errno != {EAGAIN,ENOSYS} "
- "(errno=%i)", errno);
+ {
+ struct timespec ts = { 0 /* sec */, 500000000 /* nsec */ };
+ if (semtimedop (semid, &sb2, 1, &ts) != -1
+ || (errno != EAGAIN && errno != ENOSYS))
+ FAIL_EXIT1 ("semtimedop succeed or returned errno != {EAGAIN,ENOSYS} "
+ "(errno=%i)", errno);
+ }
+
+ {
+ support_create_timer (0, 100000000, false, NULL);
+ struct timespec ts = { TYPE_MAXIMUM (time_t), 0 };
+ TEST_COMPARE (semtimedop (semid, &sb2, 1, &ts), -1);
+ TEST_VERIFY (errno == EINTR || errno == EOVERFLOW);
+ }
#endif
/* Finally free up the semnaphore resource. */