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hurd: make wait4 a cancellation point

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and add _nocancel variant.

* sysdeps/mach/hurd/Makefile [io] (sysdep_routines): Add wait4_nocancel.
* sysdeps/mach/hurd/wait4.c: Include <sysdep-cancel.h>
(__wait4): Surround __proc_wait with enabling async cancel, and use
__USEPORT_CANCEL instead of __USEPORT.
* sysdeps/mach/hurd/wait4_nocancel.c: New file, contains previous
implementation of __wait4.
* sysdeps/mach/hurd/not-cancel.h (__waitpid_nocancel): Replace macro with
__wait4_nocancel declaration with hidden proto, and make
__waitpid_nocancel call __wait4_nocancel.
This commit is contained in:
Samuel Thibault 2020-06-28 16:54:49 +00:00
parent d60fdd480d
commit 09effdc9b0
4 changed files with 70 additions and 6 deletions
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3
sysdeps/mach/hurd/Makefile
View file

@ -198,7 +198,8 @@ endif
ifeq (io, $(subdir))
sysdep_routines += f_setlk close_nocancel close_nocancel_nostatus \
open_nocancel openat_nocancel read_nocancel \
pread64_nocancel write_nocancel pwrite64_nocancel
pread64_nocancel write_nocancel pwrite64_nocancel \
wait4_nocancel
endif
ifeq (misc, $(subdir))

9
sysdeps/mach/hurd/not-cancel.h
View file

@ -63,9 +63,13 @@ __typeof (__writev) __writev_nocancel;
/* Non cancellable writev syscall with no status. */
void __writev_nocancel_nostatus (int fd, const struct iovec *vector, int count);
/* For now we have none. Map the name to the normal functions. */
/* Non cancellable wait4 syscall. */
__typeof (__wait4) __wait4_nocancel;
# define __waitpid_nocancel(pid, stat_loc, options) \
__waitpid (pid, stat_loc, options)
__wait4_nocancel (pid, stat_loc, options, NULL)
/* For now we have none. Map the name to the normal functions. */
#define __fcntl64_nocancel(fd, cmd, ...) \
__fcntl64 (fd, cmd, __VA_ARGS__)
@ -80,6 +84,7 @@ hidden_proto (__write_nocancel)
hidden_proto (__pwrite64_nocancel)
hidden_proto (__writev_nocancel)
hidden_proto (__writev_nocancel_nostatus)
hidden_proto (__wait4_nocancel)
#endif
#endif /* NOT_CANCEL_H */

10
sysdeps/mach/hurd/wait4.c
View file

@ -20,6 +20,7 @@
#include <errno.h>
#include <hurd.h>
#include <hurd/port.h>
#include <sysdep-cancel.h>
pid_t
__wait4 (pid_t pid, int *stat_loc, int options, struct rusage *usage)
@ -29,10 +30,13 @@ __wait4 (pid_t pid, int *stat_loc, int options, struct rusage *usage)
struct rusage ignored;
int sigcode;
int dummy;
int cancel_oldtype;
err = __USEPORT (PROC, __proc_wait (port, pid, options,
stat_loc ?: &dummy, &sigcode,
usage ?: &ignored, &dead));
cancel_oldtype = LIBC_CANCEL_ASYNC();
err = __USEPORT_CANCEL (PROC, __proc_wait (port, pid, options,
stat_loc ?: &dummy, &sigcode,
usage ?: &ignored, &dead));
LIBC_CANCEL_RESET (cancel_oldtype);
switch (err)
{
case 0: /* Got a child. */

54
sysdeps/mach/hurd/wait4_nocancel.c Normal file
View file

@ -0,0 +1,54 @@
/* Copyright (C) 1993-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <sys/types.h>
#include <sys/wait.h>
#include <errno.h>
#include <hurd.h>
#include <hurd/port.h>
#include <not-cancel.h>
pid_t
__wait4_nocancel (pid_t pid, int *stat_loc, int options, struct rusage *usage)
{
pid_t dead;
error_t err;
struct rusage ignored;
int sigcode;
int dummy;
err = __USEPORT (PROC, __proc_wait (port, pid, options,
stat_loc ?: &dummy, &sigcode,
usage ?: &ignored, &dead));
switch (err)
{
case 0: /* Got a child. */
return dead;
case EAGAIN:
/* The RPC returns this error when the WNOHANG flag is set and no
selected children are dead (but some are living). In that
situation, our return value is zero. (The RPC can't return zero
for DEAD without also returning some garbage for the other out
parameters, so an error return is much more natural here. Hence
the difference between the RPC and the POSIX.1 interface. */
return (pid_t) 0;
default:
return (pid_t) __hurd_fail (err);
}
}
libc_hidden_def (__wait4_nocancel)