[RFC 03/10] y2038: Convert __lll_futex* functions to use futex_time64 when available
Lukasz Majewski
lukma@denx.de
Tue Jul 7 15:08:20 GMT 2020
As the 'futex' syscall is wrapped with a C preprocessor macros, it was
necessary to provide new set of those to replace call it with Y2038
safe 'futex_time64' syscall.
The current code expand wrapper's arguments as __VA_ARGS__ when more than
three arguments are passed. For the conversion it was necessary to also
have 'timeout' explicitly passed, and hence the introduction of
lll_futex_syscall_time64_4 and lll_futex_syscall_time64 functions.
The former expects exactly 4 arguments - timeout is the last one.
Signed-off-by: Lukasz Majewski <lukma@denx.de>
---
sysdeps/nptl/lowlevellock-futex.h | 80 ++++++++++++++++++++++++++++---
sysdeps/nptl/lowlevellock.h | 2 +-
2 files changed, 75 insertions(+), 7 deletions(-)
diff --git a/sysdeps/nptl/lowlevellock-futex.h b/sysdeps/nptl/lowlevellock-futex.h
index 2209ca76a1..a686773db4 100644
--- a/sysdeps/nptl/lowlevellock-futex.h
+++ b/sysdeps/nptl/lowlevellock-futex.h
@@ -65,14 +65,82 @@
(((fl) | FUTEX_PRIVATE_FLAG) ^ (private))
# endif
-# define lll_futex_syscall(nargs, futexp, op, ...) \
+# define __lll_futex_syscall(nargs, futexp, op, ...) \
({ \
- long int __ret = INTERNAL_SYSCALL (futex, nargs, futexp, op, \
+ long int __ret = INTERNAL_SYSCALL (futex, nargs, futexp, op, \
__VA_ARGS__); \
(__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (__ret)) \
? -INTERNAL_SYSCALL_ERRNO (__ret) : 0); \
})
+# define __lll_futex_syscall64(nargs, futexp, op, ...) \
+ ({ \
+ long int __ret = INTERNAL_SYSCALL (futex_time64, nargs, futexp, op, \
+ __VA_ARGS__); \
+ (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (__ret)) \
+ ? -INTERNAL_SYSCALL_ERRNO (__ret) : 0); \
+ })
+
+# ifdef __ASSUME_TIME64_SYSCALLS
+# ifndef __NR_futex_time64
+# define __NR_futex_time64 __NR_futex
+# endif
+# define lll_futex_syscall(nargs, futexp, op, ...) \
+ __lll_futex_syscall64(nargs, futexp, op, __VA_ARGS__)
+# define lll_futex_syscall_time64_4(nargs, futexp, op, val, timeout)\
+ __lll_futex_syscall64(nargs, futexp, op, val, timeout)
+# define lll_futex_syscall_time64(nargs, futexp, op, val, timeout, ...)\
+ __lll_futex_syscall64(nargs, futexp, op, val, timeout, __VA_ARGS__)
+# else
+inline static long int
+__lll_futex_syscall_time_check (long int __ret, const struct __timespec64 *t)
+{
+ if (! (__ret == 0 || errno != ENOSYS))
+ if (t != NULL && ! in_time_t_range (t->tv_sec))
+ __ret = ({ errno = (EOVERFLOW); -1l; });
+ return __ret;
+}
+# define lll_futex_syscall(nargs, futexp, op, ...) \
+ ({ \
+ long int __ret = \
+ __lll_futex_syscall64(nargs, futexp, op, __VA_ARGS__); \
+ if (! (__ret == 0 || errno != ENOSYS)) \
+ __ret = \
+ __lll_futex_syscall(nargs, futexp, op, __VA_ARGS__); \
+ __ret; \
+ })
+
+# define lll_futex_syscall_time64(nargs, futexp, op, val, timeout, ...)\
+ ({ \
+ struct timespec __ts32; \
+ if (timeout != NULL) \
+ __ts32 = valid_timespec64_to_timespec (*((struct __timespec64*) timeout)); \
+ long int __ret = \
+ __lll_futex_syscall64(nargs, futexp, op, val, timeout,\
+ __VA_ARGS__); \
+ __ret = __lll_futex_syscall_time_check (__ret, timeout); \
+ if (__ret != 0) \
+ __ret = __lll_futex_syscall(nargs, futexp, op, val, \
+ timeout != NULL ? &__ts32 : NULL, \
+ __VA_ARGS__); \
+ __ret; \
+ })
+
+# define lll_futex_syscall_time64_4(nargs, futexp, op, val, timeout)\
+ ({ \
+ struct timespec __ts32; \
+ if (timeout != NULL) \
+ __ts32 = valid_timespec64_to_timespec (*((struct __timespec64*) timeout)); \
+ long int __ret = \
+ __lll_futex_syscall64(nargs, futexp, op, val, timeout); \
+ __ret = __lll_futex_syscall_time_check (__ret, timeout); \
+ if (__ret != 0) \
+ __ret = __lll_futex_syscall(nargs, futexp, op, val, \
+ timeout != NULL ? &__ts32 : NULL); \
+ __ret; \
+ })
+
+# endif
/* For most of these macros, the return value is never really used.
Nevertheless, the protocol is that each one returns a negated errno
code for failure or zero for success. (Note that the corresponding
@@ -85,7 +153,7 @@
lll_futex_timed_wait (futexp, val, NULL, private)
# define lll_futex_timed_wait(futexp, val, timeout, private) \
- lll_futex_syscall (4, futexp, \
+ lll_futex_syscall_time64_4 (4, futexp, \
__lll_private_flag (FUTEX_WAIT, private), \
val, timeout)
@@ -107,7 +175,7 @@
const int op = \
__lll_private_flag (FUTEX_WAIT_BITSET | clockbit, private); \
\
- __ret = lll_futex_syscall (6, futexp, op, val, \
+ __ret = lll_futex_syscall_time64 (6, futexp, op, val, \
timeout, NULL /* Unused. */, \
FUTEX_BITSET_MATCH_ANY); \
} \
@@ -118,7 +186,7 @@
/* Wake up up to NR waiters on FUTEXP. */
# define lll_futex_wake(futexp, nr, private) \
- lll_futex_syscall (4, futexp, \
+ lll_futex_syscall_time64_4 (4, futexp, \
__lll_private_flag (FUTEX_WAKE, private), nr, 0)
/* Wake up up to NR_WAKE waiters on FUTEXP. Move up to NR_MOVE of the
@@ -159,7 +227,7 @@
/* Like lll_futex_wait_requeue_pi, but with a timeout. */
# define lll_futex_timed_wait_requeue_pi(futexp, val, timeout, clockbit, \
mutex, private) \
- lll_futex_syscall (5, futexp, \
+ lll_futex_syscall_time64 (5, futexp, \
__lll_private_flag (FUTEX_WAIT_REQUEUE_PI \
| (clockbit), private), \
val, timeout, mutex)
diff --git a/sysdeps/nptl/lowlevellock.h b/sysdeps/nptl/lowlevellock.h
index 68b3be8819..864152e609 100644
--- a/sysdeps/nptl/lowlevellock.h
+++ b/sysdeps/nptl/lowlevellock.h
@@ -123,7 +123,7 @@ extern void __lll_lock_wait (int *futex, int private) attribute_hidden;
extern int __lll_clocklock_wait (int *futex, int val, clockid_t,
- const struct timespec *,
+ const struct __timespec64 *,
int private) attribute_hidden;
#define lll_timedwait(futex, val, clockid, abstime, private) \
--
2.20.1
More information about the Libc-alpha
mailing list