linux: Add time64 select support

The syscall __NR_pselect6_time64 (32-bit) or __NR_pselect6 (64-bit)
is used as default.  For architectures with __ASSUME_TIME64_SYSCALLS
the 32-bit fallback uses __NR_select/__NR__newselect or __NR_pselect6
(it should cover the microblaze case where older kernels do not
provide __NR_pselect6).

Checked on x86_64-linux-gnu and i686-linux-gnu (on 5.4 and on 4.15
kernel).

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
This commit is contained in:
Adhemerval Zanella 2020-07-06 16:06:51 -03:00
parent 50e19ddfcd
commit 2433d39b69
3 changed files with 88 additions and 28 deletions

View file

@ -5,8 +5,11 @@
/* Now define the internal interfaces. */
# if __TIMESIZE == 64
# define __pselect64 __pselect
# define __select64 __select
#else
# include <struct___timespec64.h>
# include <struct___timeval64.h>
extern int __pselect64 (int __nfds, fd_set *__readfds,
fd_set *__writefds, fd_set *__exceptfds,
const struct __timespec64 *__timeout,
@ -18,6 +21,11 @@ extern int __pselect32 (int __nfds, fd_set *__readfds,
const struct __timespec64 *__timeout,
const __sigset_t *__sigmask)
attribute_hidden;
extern int __select64 (int __nfds, fd_set *__readfds,
fd_set *__writefds, fd_set *__exceptfds,
struct __timeval64 *__timeout);
libc_hidden_proto (__select64)
#endif
extern int __pselect (int __nfds, fd_set *__readfds,
fd_set *__writefds, fd_set *__exceptfds,

View file

@ -464,6 +464,12 @@ valid_timespec_to_timeval32 (const struct timespec ts)
return (struct __timeval32) { (time_t) ts.tv_sec, ts.tv_nsec / 1000 };
}
static inline struct __timeval64
valid_timespec_to_timeval64 (const struct timespec ts)
{
return (struct __timeval64) { (time_t) ts.tv_sec, ts.tv_nsec / 1000 };
}
/* Check if a value is in the valid nanoseconds range. Return true if
it is, false otherwise. */
static inline bool

View file

@ -21,6 +21,7 @@
#include <sys/select.h>
#include <errno.h>
#include <sysdep-cancel.h>
#include <time64-support.h>
/* Check the first NFDS descriptors each in READFDS (if not NULL) for read
readiness, in WRITEFDS (if not NULL) for write readiness, and in EXCEPTFDS
@ -28,43 +29,88 @@
after waiting the interval specified therein. Returns the number of ready
descriptors, or -1 for errors. */
#ifdef __NR__newselect
# undef __NR_select
# define __NR_select __NR__newselect
int
__select64 (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
struct __timeval64 *timeout)
{
struct __timespec64 ts64, *pts64 = NULL;
if (timeout != NULL)
{
ts64 = timeval64_to_timespec64 (*timeout);
pts64 = &ts64;
}
#ifndef __NR_pselect6_time64
# define __NR_pselect6_time64 __NR_pselect6
#endif
int r;
if (supports_time64 ())
{
r = SYSCALL_CANCEL (pselect6_time64, nfds, readfds, writefds, exceptfds,
pts64, NULL);
/* Linux by default will update the timeout after a pselect6 syscall
(though the pselect() glibc call suppresses this behavior).
Since select() on Linux has the same behavior as the pselect6
syscall, we update the timeout here. */
if (r == 0 || errno != ENOSYS)
{
if (timeout != NULL)
TIMEVAL_TO_TIMESPEC (timeout, &ts64);
return r;
}
mark_time64_unsupported ();
}
#ifndef __ASSUME_TIME64_SYSCALLS
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 (ts64);
pts32 = &ts32;
}
# ifndef __ASSUME_PSELECT
# ifdef __NR__newselect
# undef __NR_select
# define __NR_select __NR__newselect
# endif
r = SYSCALL_CANCEL (select, nfds, readfds, writefds, exceptfds, pts32);
# else
r = SYSCALL_CANCEL (pselect6, nfds, readfds, writefds, exceptfds, pts32,
NULL);
# endif
if (r >= 0 && timeout != NULL)
*timeout = valid_timespec_to_timeval64 (ts32);
#endif
return r;
}
#if __TIMESIZE != 64
libc_hidden_def (__select64)
int
__select (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
struct timeval *timeout)
{
#ifdef __NR_select
return SYSCALL_CANCEL (select, nfds, readfds, writefds, exceptfds,
timeout);
#else
int result;
struct timespec ts, *tsp = NULL;
if (timeout)
struct __timeval64 tv64, *ptv64 = NULL;
if (timeout != NULL)
{
TIMEVAL_TO_TIMESPEC (timeout, &ts);
tsp = &ts;
tv64 = valid_timeval_to_timeval64 (*timeout);
ptv64 = &tv64;
}
result = SYSCALL_CANCEL (pselect6, nfds, readfds, writefds, exceptfds, tsp,
NULL);
if (timeout)
{
/* Linux by default will update the timeout after a pselect6 syscall
(though the pselect() glibc call suppresses this behavior).
Since select() on Linux has the same behavior as the pselect6
syscall, we update the timeout here. */
TIMESPEC_TO_TIMEVAL (timeout, &ts);
}
return result;
#endif
int r = __select64 (nfds, readfds, writefds, exceptfds, ptv64);
if (r >= 0 && timeout != NULL)
/* The remanining timeout will be always less the input TIMEOUT. */
*timeout = valid_timeval64_to_timeval (tv64);
return r;
}
#endif
libc_hidden_def (__select)
weak_alias (__select, select)