diff mbox series

[17/23] linux: Add time64 select support

Message ID 20200713171025.3661832-17-adhemerval.zanella@linaro.org
State New
Headers show
Series [01/23] linux: Simplify clock_adjtime | expand

Commit Message

Adhemerval Zanella July 13, 2020, 5:10 p.m. UTC
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).
---
 include/sys/select.h             |  8 +++
 include/time.h                   |  6 ++
 sysdeps/unix/sysv/linux/select.c | 96 +++++++++++++++++++++++---------
 3 files changed, 83 insertions(+), 27 deletions(-)
diff mbox series

Patch

diff --git a/include/sys/select.h b/include/sys/select.h
index 460dee9295..370b662ea7 100644
--- a/include/sys/select.h
+++ b/include/sys/select.h
@@ -5,13 +5,21 @@ 
 /* 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,
 			const __sigset_t *__sigmask);
 libc_hidden_proto (__pselect64)
+
+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,
diff --git a/include/time.h b/include/time.h
index fe4da9ca10..936486e206 100644
--- a/include/time.h
+++ b/include/time.h
@@ -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
diff --git a/sysdeps/unix/sysv/linux/select.c b/sysdeps/unix/sysv/linux/select.c
index 54c50edba2..df4fcc3362 100644
--- a/sysdeps/unix/sysv/linux/select.c
+++ b/sysdeps/unix/sysv/linux/select.c
@@ -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 +29,84 @@ 
    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
-#endif
-
 int
-__select (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
-	  struct timeval *timeout)
+__select64 (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
+	    struct __timeval64 *timeout)
 {
-#ifdef __NR_select
-  return SYSCALL_CANCEL (select, nfds, readfds, writefds, exceptfds,
-			 timeout);
-#else
-  int result;
-  struct timespec ts, *tsp = NULL;
-
-  if (timeout)
+  struct __timespec64 ts64, *pts64 = NULL;
+  if (timeout != NULL)
     {
-      TIMEVAL_TO_TIMESPEC (timeout, &ts);
-      tsp = &ts;
+      ts64 = timeval64_to_timespec64 (*timeout);
+      pts64 = &ts64;
     }
 
-  result = SYSCALL_CANCEL (pselect6, nfds, readfds, writefds, exceptfds, tsp,
-			   NULL);
-
-  if (timeout)
+#ifndef __NR_pselect6_time64
+# define __NR_pselect6_time64 __NR_pselect6
+#endif
+  int r;
+  if (supports_time64 ())
     {
-      /* 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);
+      r = SYSCALL_CANCEL (pselect6_time64, nfds, readfds, writefds, exceptfds,
+			  pts64, NULL);
+      if (r == 0 || errno != ENOSYS)
+	{
+	  if (timeout != NULL)
+	    TIMEVAL_TO_TIMESPEC (timeout, &ts64);
+	  return r;
+	}
+
+      mark_time64_unsupported ();
     }
 
-  return result;
+#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)
+{
+  struct __timeval64 tv64, *ptv64 = NULL;
+  if (timeout != 0)
+    {
+      tv64 = valid_timeval_to_timeval64 (*timeout);
+      ptv64 = &tv64;
+    }
+  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)