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authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2021-06-15 16:59:50 -0300
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2021-06-22 12:09:52 -0300
commit91cf411ad3ef10bd18ec053854fcb919be4f6789 (patch)
tree9d3f802bd16bda2cee81aa61509384890b9f596f
parentecf2661281c71a9752c7238ab93bc12b16cfff23 (diff)
downloadglibc-91cf411ad3ef10bd18ec053854fcb919be4f6789.tar.gz
linux: Only use 64-bit syscall if required for pselect
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. This also avoids the need to use supports_time64() (which breaks the usage case of live migration like CRIU or similar). 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. Reviewed-by: Lukasz Majewski <lukma@denx.de>
-rw-r--r--misc/Makefile9
-rw-r--r--misc/tst-pselect.c120
-rw-r--r--sysdeps/unix/sysv/linux/microblaze/pselect32.c3
-rw-r--r--sysdeps/unix/sysv/linux/pselect.c47
-rw-r--r--sysdeps/unix/sysv/linux/pselect32.c6
5 files changed, 94 insertions, 91 deletions
diff --git a/misc/Makefile b/misc/Makefile
index f34ab09fe3..fa40bf0e11 100644
--- a/misc/Makefile
+++ b/misc/Makefile
@@ -148,6 +148,12 @@ CFLAGS-brk.op = $(no-stack-protector)
include ../Rules
+ifeq (yes,$(build-shared))
+librt = $(common-objpfx)rt/librt.so
+else
+librt = $(common-objpfx)rt/librt.a
+endif
+
$(objpfx)libg.a: $(dep-dummy-lib); $(make-dummy-lib)
$(objpfx)tst-tsearch: $(libm)
@@ -162,3 +168,6 @@ tst-allocate_once-ENV = MALLOC_TRACE=$(objpfx)tst-allocate_once.mtrace
$(objpfx)tst-allocate_once-mem.out: $(objpfx)tst-allocate_once.out
$(common-objpfx)malloc/mtrace $(objpfx)tst-allocate_once.mtrace > $@; \
$(evaluate-test)
+
+$(objpfx)tst-pselect: $(librt)
+$(objpfx)tst-pselect-time64: $(librt)
diff --git a/misc/tst-pselect.c b/misc/tst-pselect.c
index c89176b058..f8c404c275 100644
--- a/misc/tst-pselect.c
+++ b/misc/tst-pselect.c
@@ -16,14 +16,14 @@
<https://www.gnu.org/licenses/>. */
#include <errno.h>
-#include <signal.h>
-#include <stdio.h>
-#include <unistd.h>
-#include <sys/select.h>
-#include <sys/wait.h>
+#include <intprops.h>
+#include <support/check.h>
+#include <support/support.h>
+#include <support/xsignal.h>
+#include <support/xunistd.h>
+#include <support/xtime.h>
#include <stdlib.h>
-
static volatile int handler_called;
static void
@@ -33,59 +33,43 @@ handler (int sig)
}
-static int
-do_test (void)
+static void
+test_pselect_basic (void)
{
struct sigaction sa;
sa.sa_handler = handler;
sa.sa_flags = 0;
sigemptyset (&sa.sa_mask);
- if (sigaction (SIGUSR1, &sa, NULL) != 0)
- {
- puts ("sigaction failed");
- return 1;
- }
+ xsigaction (SIGUSR1, &sa, NULL);
sa.sa_handler = SIG_IGN;
- if (sigaction (SIGCHLD, &sa, NULL) != 0)
- {
- puts ("2nd sigaction failed");
- return 1;
- }
+ xsigaction (SIGCHLD, &sa, NULL);
sigset_t ss_usr1;
sigemptyset (&ss_usr1);
sigaddset (&ss_usr1, SIGUSR1);
- if (sigprocmask (SIG_BLOCK, &ss_usr1, NULL) != 0)
- {
- puts ("sigprocmask failed");
- return 1;
- }
+ TEST_COMPARE (sigprocmask (SIG_BLOCK, &ss_usr1, NULL), 0);
int fds[2][2];
-
- if (pipe (fds[0]) != 0 || pipe (fds[1]) != 0)
- {
- puts ("pipe failed");
- return 1;
- }
+ xpipe (fds[0]);
+ xpipe (fds[1]);
fd_set rfds;
FD_ZERO (&rfds);
sigset_t ss;
- sigprocmask (SIG_SETMASK, NULL, &ss);
+ TEST_COMPARE (sigprocmask (SIG_SETMASK, NULL, &ss), 0);
sigdelset (&ss, SIGUSR1);
struct timespec to = { .tv_sec = 0, .tv_nsec = 500000000 };
pid_t parent = getpid ();
- pid_t p = fork ();
+ pid_t p = xfork ();
if (p == 0)
{
- close (fds[0][1]);
- close (fds[1][0]);
+ xclose (fds[0][1]);
+ xclose (fds[1][0]);
FD_SET (fds[0][0], &rfds);
@@ -93,55 +77,63 @@ do_test (void)
do
{
if (getppid () != parent)
- exit (2);
+ FAIL_EXIT1 ("getppid()=%d != parent=%d", getppid(), parent);
errno = 0;
e = pselect (fds[0][0] + 1, &rfds, NULL, NULL, &to, &ss);
}
while (e == 0);
- if (e != -1)
- {
- puts ("child: pselect did not fail");
- return 0;
- }
- if (errno != EINTR)
- {
- puts ("child: pselect did not set errno to EINTR");
- return 0;
- }
+ TEST_COMPARE (e, -1);
+ TEST_COMPARE (errno, EINTR);
TEMP_FAILURE_RETRY (write (fds[1][1], "foo", 3));
exit (0);
}
- close (fds[0][0]);
- close (fds[1][1]);
+ xclose (fds[0][0]);
+ xclose (fds[1][1]);
FD_SET (fds[1][0], &rfds);
- kill (p, SIGUSR1);
+ TEST_COMPARE (kill (p, SIGUSR1), 0);
int e = pselect (fds[1][0] + 1, &rfds, NULL, NULL, NULL, &ss);
- if (e == -1)
- {
- puts ("parent: pselect failed");
- return 1;
- }
- if (e != 1)
- {
- puts ("parent: pselect did not report readable fd");
- return 1;
- }
- if (!FD_ISSET (fds[1][0], &rfds))
- {
- puts ("parent: pselect reports wrong fd");
- return 1;
- }
+ TEST_COMPARE (e, 1);
+ TEST_VERIFY (FD_ISSET (fds[1][0], &rfds));
+}
+
+static void
+test_pselect_large_timeout (void)
+{
+ support_create_timer (0, 100000000, false, NULL);
+
+ int fds[2];
+ xpipe (fds);
+
+ fd_set rfds;
+ FD_ZERO (&rfds);
+ FD_SET (fds[0], &rfds);
+
+ sigset_t ss;
+ TEST_COMPARE (sigprocmask (SIG_SETMASK, NULL, &ss), 0);
+ sigdelset (&ss, SIGALRM);
+
+ struct timespec ts = { TYPE_MAXIMUM (time_t), 0 };
+
+ TEST_COMPARE (pselect (fds[0] + 1, &rfds, NULL, NULL, &ts, &ss), -1);
+ TEST_VERIFY (errno == EINTR || errno == EOVERFLOW);
+}
+
+static int
+do_test (void)
+{
+ test_pselect_basic ();
+
+ test_pselect_large_timeout ();
return 0;
}
-#define TEST_FUNCTION do_test ()
-#include "../test-skeleton.c"
+#include <support/test-driver.c>
diff --git a/sysdeps/unix/sysv/linux/microblaze/pselect32.c b/sysdeps/unix/sysv/linux/microblaze/pselect32.c
index a4f436462b..70b7b52a48 100644
--- a/sysdeps/unix/sysv/linux/microblaze/pselect32.c
+++ b/sysdeps/unix/sysv/linux/microblaze/pselect32.c
@@ -35,8 +35,7 @@ __pselect32 (int nfds, fd_set *readfds, fd_set *writefds,
struct timeval tv32, *ptv32 = NULL;
if (timeout != NULL)
{
- if (! in_time_t_range (timeout->tv_sec)
- || ! valid_nanoseconds (timeout->tv_nsec))
+ if (! valid_nanoseconds (timeout->tv_nsec))
{
__set_errno (EINVAL);
return -1;
diff --git a/sysdeps/unix/sysv/linux/pselect.c b/sysdeps/unix/sysv/linux/pselect.c
index 5e8a0cc2dc..e7df6e7465 100644
--- a/sysdeps/unix/sysv/linux/pselect.c
+++ b/sysdeps/unix/sysv/linux/pselect.c
@@ -18,7 +18,23 @@
#include <sys/select.h>
#include <sysdep-cancel.h>
-#include <time64-support.h>
+
+static int
+pselect64_syscall (int nfds, fd_set *readfds, fd_set *writefds,
+ fd_set *exceptfds, const struct __timespec64 *timeout,
+ const sigset_t *sigmask)
+{
+#ifndef __NR_pselect6_time64
+# define __NR_pselect6_time64 __NR_pselect6
+#endif
+ /* NB: This is required by ARGIFY used in x32 internal_syscallN. */
+ __syscall_ulong_t data[2] =
+ {
+ (uintptr_t) sigmask, __NSIG_BYTES
+ };
+ return SYSCALL_CANCEL (pselect6_time64, nfds, readfds, writefds, exceptfds,
+ timeout, data);
+}
int
__pselect64 (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
@@ -37,30 +53,23 @@ __pselect64 (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
we can only pass in 6 directly. If there is an architecture with
support for more parameters a new version of this file needs to
be created. */
-
-#ifndef __NR_pselect6_time64
-# define __NR_pselect6_time64 __NR_pselect6
-#endif
- int r;
- if (supports_time64 ())
+#ifdef __ASSUME_TIME64_SYSCALLS
+ return pselect64_syscall (nfds, readfds, writefds, exceptfds, timeout,
+ sigmask);
+#else
+ bool need_time64 = timeout != NULL && !in_time_t_range (timeout->tv_sec);
+ if (need_time64)
{
- /* NB: This is required by ARGIFY used in x32 internal_syscallN. */
- __syscall_ulong_t data[2] =
- {
- (uintptr_t) sigmask, __NSIG_BYTES
- };
- r = SYSCALL_CANCEL (pselect6_time64, nfds, readfds, writefds, exceptfds,
- timeout, data);
+ int r = pselect64_syscall (nfds, readfds, writefds, exceptfds, timeout,
+ sigmask);
if (r == 0 || errno != ENOSYS)
return r;
-
- mark_time64_unsupported ();
+ __set_errno (EOVERFLOW);
+ return -1;
}
-#ifndef __ASSUME_TIME64_SYSCALLS
- r = __pselect32 (nfds, readfds, writefds, exceptfds, timeout, sigmask);
+ return __pselect32 (nfds, readfds, writefds, exceptfds, timeout, sigmask);
#endif
- return r;
}
#if __TIMESIZE != 64
diff --git a/sysdeps/unix/sysv/linux/pselect32.c b/sysdeps/unix/sysv/linux/pselect32.c
index eb59b51cdf..48724d8727 100644
--- a/sysdeps/unix/sysv/linux/pselect32.c
+++ b/sysdeps/unix/sysv/linux/pselect32.c
@@ -29,12 +29,6 @@ __pselect32 (int nfds, fd_set *readfds, fd_set *writefds,
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;
}