Hi
This patch is one of the required adjustments for the fix for bz12683
(Race conditions in pthread cancellation) and the idea is to not rely
on the non-cancelable entry points for cancelable syscalls (since the
upcoming fill will remove them).
This patch uses inline calls (through INLINE_SYSCALL macro) to define
the non-cancellable functions macros to avoid use of the
syscall_nocancel entrypoint.
Tested on i386, x86_64, x32, powerpc32, powerpc64, arm, and aarch64.
---
* sysdeps/unix/sysv/linux/not-cancel.h (open_not_cancel): Rewrite to
be an inline implementation regardless of library is built within.
(open_not_cancel_2): Likewise.
(__read_nocancel): Likewise.
(__write_nocancel): Likewise.
(openat_not_cancel): Likewise.
(openat_not_cancel_3): Likewise.
(openat64_not_cancel): Likewise.
(openat64_not_cancel_3): Likewise.
(__close_nocancel): Likewise.
(pause_not_cancel): Likewise.
(nanosleep_not_cancel): Likewise.
(sigsuspend_not_cancel): Likewise.
--
diff --git a/sysdeps/unix/sysv/linux/not-cancel.h b/sysdeps/unix/sysv/linux/not-cancel.h
index 62d487f..8a358fd 100644
--- a/sysdeps/unix/sysv/linux/not-cancel.h
+++ b/sysdeps/unix/sysv/linux/not-cancel.h
@@ -17,48 +17,48 @@
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
+#ifndef NOT_CANCEL_H
+# define NOT_CANCEL_H
+
#include <sysdep.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/syscall.h>
-#if IS_IN (libc) || IS_IN (libpthread) || IS_IN (librt)
-extern int __open_nocancel (const char *, int, ...) attribute_hidden;
-extern int __close_nocancel (int) attribute_hidden;
-extern int __read_nocancel (int, void *, size_t) attribute_hidden;
-extern int __write_nocancel (int, const void *, size_t) attribute_hidden;
-extern pid_t __waitpid_nocancel (pid_t, int *, int) attribute_hidden;
-extern int __openat_nocancel (int fd, const char *fname, int oflag,
- mode_t mode) attribute_hidden;
-extern int __openat64_nocancel (int fd, const char *fname, int oflag,
- mode_t mode) attribute_hidden;
+/* Uncancelable open. */
+#ifdef __NR_open
+# define open_not_cancel(name, flags, mode) \
+ INLINE_SYSCALL (open, 3, name, flags, mode)
+# define open_not_cancel_2(name, flags) \
+ INLINE_SYSCALL (open, 2, name, flags)
#else
-# define __open_nocancel(name, ...) __open (name, __VA_ARGS__)
-# define __close_nocancel(fd) __close (fd)
-# define __read_nocancel(fd, buf, len) __read (fd, buf, len)
-# define __write_nocancel(fd, buf, len) __write (fd, buf, len)
-# define __waitpid_nocancel(pid, stat_loc, options) \
- __waitpid (pid, stat_loc, options)
-# define __openat_nocancel(fd, fname, oflag, mode) \
- openat (fd, fname, oflag, mode)
-# define __openat64_nocancel(fd, fname, oflag, mode) \
- openat64 (fd, fname, oflag, mode)
+# define open_not_cancel(name, flags, mode) \
+ INLINE_SYSCALL (openat, 4, AT_FDCWD, name, flags, mode)
+# define open_not_cancel_2(name, flags) \
+ INLINE_SYSCALL (openat, 3, AT_FDCWD, name, flags)
#endif
-/* Uncancelable open. */
-#define open_not_cancel(name, flags, mode) \
- __open_nocancel (name, flags, mode)
-#define open_not_cancel_2(name, flags) \
- __open_nocancel (name, flags)
+/* Uncancelable read. */
+#define __read_nocancel(fd, buf, len) \
+ INLINE_SYSCALL (read, 3, fd, buf, len)
+
+/* Uncancelable write. */
+#define __write_nocancel(fd, buf, len) \
+ INLINE_SYSCALL (write, 3, fd, buf, len)
/* Uncancelable openat. */
#define openat_not_cancel(fd, fname, oflag, mode) \
- __openat_nocancel (fd, fname, oflag, mode)
+ INLINE_SYSCALL (openat, 4, fd, fname, oflag, mode)
#define openat_not_cancel_3(fd, fname, oflag) \
- __openat_nocancel (fd, fname, oflag, 0)
+ INLINE_SYSCALL (openat, 3, fd, fname, oflag)
#define openat64_not_cancel(fd, fname, oflag, mode) \
- __openat64_nocancel (fd, fname, oflag, mode)
+ INLINE_SYSCALL (openat, 4, fd, fname, oflag | O_LARGEFILE, mode)
#define openat64_not_cancel_3(fd, fname, oflag) \
- __openat64_nocancel (fd, fname, oflag, 0)
+ INLINE_SYSCALL (openat, 3, fd, fname, oflag | O_LARGEFILE)
/* Uncancelable close. */
+#define __close_nocancel(fd) \
+ INLINE_SYSCALL (close, 1, fd)
#define close_not_cancel(fd) \
__close_nocancel (fd)
#define close_not_cancel_no_status(fd) \
@@ -83,17 +83,27 @@ extern int __openat64_nocancel (int fd, const char *fname, int oflag,
__fcntl_nocancel (fd, cmd, val)
/* Uncancelable waitpid. */
-#define waitpid_not_cancel(pid, stat_loc, options) \
+#define __waitpid_nocancel(pid, stat_loc, options) \
INLINE_SYSCALL (wait4, 4, pid, stat_loc, options, NULL)
+#define waitpid_not_cancel(pid, stat_loc, options) \
+ __waitpid_nocancel(pid, stat_loc, options)
/* Uncancelable pause. */
#define pause_not_cancel() \
- __pause_nocancel ()
+ ({ sigset_t set; \
+ int __rc = INLINE_SYSCALL (rt_sigprocmask, 4, SIG_BLOCK, NULL, &set, \
+ _NSIG / 8); \
+ if (__rc == 0) \
+ __rc = INLINE_SYSCALL (rt_sigsuspend, 2, &set, _NSIG / 8); \
+ __rc; \
+ })
/* Uncancelable nanosleep. */
#define nanosleep_not_cancel(requested_time, remaining) \
- __nanosleep_nocancel (requested_time, remaining)
+ INLINE_SYSCALL (nanosleep, 2, requested_time, remaining)
/* Uncancelable sigsuspend. */
#define sigsuspend_not_cancel(set) \
- __sigsuspend_nocancel (set)
+ INLINE_SYSCALL (rt_sigsuspend, 2, set, _NSIG / 8)
+
+#endif /* NOT_CANCEL_H */
diff --git a/sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c b/sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c
index 5b6bb51..3578ea8 100644
--- a/sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c
+++ b/sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c
@@ -41,7 +41,7 @@ __get_clockfreq (void)
contains at least one line like:
timebase : 33333333
We search for this line and convert the number into an integer. */
- int fd = __open_nocancel ("/proc/cpuinfo", O_RDONLY);
+ int fd = open_not_cancel_2 ("/proc/cpuinfo", O_RDONLY);
if (__glibc_likely (fd != -1))
return result;