d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
e899a0575b
freebsd-skq/include/signal.h

133 lines
4.2 KiB
C
Raw Normal View History

BSD 4.4 Lite Include Sources
1994-05-24 09:57:34 +00:00
/*-
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
Remove the Berkeley clause 3's. Add a few $FreeBSD$
2010-02-16 19:39:50 +00:00
* 3. Neither the name of the University nor the names of its contributors
BSD 4.4 Lite Include Sources
1994-05-24 09:57:34 +00:00
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)signal.h 8.3 (Berkeley) 3/30/94
sigset_t change (part 5 of 5) ----------------------------- Most of the userland changes are in libc. For both the alpha and the i386 setjmp has been changed to accomodate for the new sigset_t. Internally, libc is mostly rewritten to use the new syscalls. The exception is in compat-43/sigcompat.c The POSIX thread library has also been rewritten to use the new sigset_t. Except, that it currently only handles NSIG signals instead of the maximum _SIG_MAXSIG. This should not be a problem because current applications don't use any signals higher than NSIG. There are version bumps for the following libraries: libdialog libreadline libc libc_r libedit libftpio libss These libraries either a) have one of the modified structures visible in the interface, or b) use sigset_t internally and may cause breakage if new binaries are used against libraries that don't have the sigset_t change. This not an immediate issue, but will be as soon as applications start using the new range to its fullest. NOTE: libncurses already had an version bump and has not been given one now. NOTE: doscmd is a real casualty and has been disconnected for the moment. Reconnection will eventually happen after doscmd has been fixed. I'm aware that being the last one to touch it, I'm automaticly promoted to being maintainer. According to good taste this means that I will receive a badge which either will be glued or mechanically stapled, drilled or otherwise violently forced onto me :-) NOTE: pcvt/vttest cannot be compiled with -traditional. The change cause sys/types to be included along the way which contains the const and volatile modifiers. I don't consider this a solution, but more a workaround.
1999-09-29 15:18:46 +00:00
* $FreeBSD$
BSD 4.4 Lite Include Sources
1994-05-24 09:57:34 +00:00
*/
Fix standards conformance bugs in <signal.h>: include/signal.h: There was massive namespace pollution from including <sys/types.h>. POSIX functions were declared even when _ANSI_SOURCE is defined. sys.sys/signal.h: NSIG was declared even if _ANSI_SOURCE or _POSIX_SOURCE is defined. sig_atomic_t wasn't declared if _POSIX_SOURCE is defined. Declare a typedef for signal handling functions and use it to unobfuscate declarations and to avoid half-baked function types that cause unwanted compiler warnings at certain warning levels. Fix confusing comment about SA_RESTART. sys/i386/include/signal.h: This has to be included to get the declaration of sig_atomic_t even when _ANSI_SOURCE is defined, so be more careful about polluting the ANSI namespace. Uniformize idempotency ifdefs.
1995-06-28 02:14:13 +00:00
#ifndef _SIGNAL_H_
#define _SIGNAL_H_
BSD 4.4 Lite Include Sources
1994-05-24 09:57:34 +00:00
#include <sys/cdefs.h>
o Merge <machine/ansi.h> and <machine/types.h> into a new header called <machine/_types.h>. o <machine/ansi.h> will continue to live so it can define MD clock macros, which are only MD because of gratuitous differences between architectures. o Change all headers to make use of this. This mainly involves changing: #ifdef _BSD_FOO_T_ typedef _BSD_FOO_T_ foo_t; #undef _BSD_FOO_T_ #endif to: #ifndef _FOO_T_DECLARED typedef __foo_t foo_t; #define _FOO_T_DECLARED #endif Concept by: bde Reviewed by: jake, obrien
2002-08-21 16:20:02 +00:00
#include <sys/_types.h>
Move the include of <machine/ansi.h> to before <sys/signal.h>.
1998-08-05 08:51:48 +00:00
#include <sys/signal.h>
Hide ucontext_t and mcontext_t when neither POSIX nor XSI features are enabled in the compilation environment, i.e. for ANSI C use of #include <signal.h>. Requested and reviewed by: bde Sponsored by: The FreeBSD Foundation MFC after: 13 days
2016-02-13 17:23:55 +00:00
#if __POSIX_VISIBLE >= 200112 || __XSI_VISIBLE
POSIX states that #include <signal.h> shall make both mcontext_t and ucontext_t available. Our code even has XXX comment about this. Add a bit of compliance by moving struct __ucontext definition into sys/_ucontext.h and including it into signal.h and sys/ucontext.h. Several machine/ucontext.h headers were changed to use namespace-safe types (like uint64_t->__uint64_t) to not depend on sys/types.h. struct __stack_t from sys/signal.h is made always visible in private namespace to satisfy sys/_ucontext.h requirements. Apparently mips _types.h pollutes global namespace with f_register_t type definition. This commit does not try to fix the issue. PR: 207079 Reported and tested by: Ting-Wei Lan <lantw44@gmail.com> Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2016-02-12 07:38:19 +00:00
#include <machine/ucontext.h>
#include <sys/_ucontext.h>
Hide ucontext_t and mcontext_t when neither POSIX nor XSI features are enabled in the compilation environment, i.e. for ANSI C use of #include <signal.h>. Requested and reviewed by: bde Sponsored by: The FreeBSD Foundation MFC after: 13 days
2016-02-13 17:23:55 +00:00
#endif
BSD 4.4 Lite Include Sources
1994-05-24 09:57:34 +00:00
Make use of clang nullability attributes. Replace uses of the GCC __nonnull__ attribute with the clang nullability qualifiers. The replacement should be transparent for clang developers as the new qualifiers will produce the same warnings and will be useful for static checkers but will not cause aggressive optimizations. GCC will not produce such warnings and developers will have to use upgraded GCC ports built with the system headers from r312538. Hinted by: Apple's Libc-1158.20.4, Bionic libc MFC after: 11.1 Release Differential Revision: https://reviews.freebsd.org/D9004
2017-01-28 20:54:43 +00:00
__NULLABILITY_PRAGMA_PUSH
o Use relatively new visibility primitives from <sys/cdefs.h>. o Add typedef for pid_t. o Add comment about missing restrict type-qualifier. o Remove unneeded includes (<sys/_posix.h> and <sys/time.h>).
2002-10-06 21:54:08 +00:00
#if __BSD_VISIBLE
o Move forward declaration for struct timespec to a more appropriate location. o Don't prototype functions for which we don't have an implementation. o Add forward declaration for struct __ucontext, previously this was forward declared in <sys/signal.h>. o Add a comment about the size of NSIG. PR: 35924 Submitted by: bde
2002-10-14 14:13:37 +00:00
/*
* XXX should enlarge these, if only to give empty names instead of bounds
* errors for large signal numbers.
*/
Replace __const by const in all non-contributed source code. As C1X is close to being released, there is no need to wrap around a feature that is already part of C90. Most of these files already use `const' in different placed as well.
2011-12-13 13:32:56 +00:00
extern const char * const sys_signame[NSIG];
extern const char * const sys_siglist[NSIG];
extern const int sys_nsig;
BSD 4.4 Lite Include Sources
1994-05-24 09:57:34 +00:00
#endif
Assume POSIX/XSI is always visible in the __BSD_VISIBLE case. Fix a mix-up with siginterrupt().
2002-10-13 00:29:06 +00:00
#if __POSIX_VISIBLE >= 200112 || __XSI_VISIBLE
o Use relatively new visibility primitives from <sys/cdefs.h>. o Add typedef for pid_t. o Add comment about missing restrict type-qualifier. o Remove unneeded includes (<sys/_posix.h> and <sys/time.h>).
2002-10-06 21:54:08 +00:00
#ifndef _PID_T_DECLARED
typedef __pid_t pid_t;
#define _PID_T_DECLARED
#endif
#endif
Fix the visibility of several prototypes. Also move pthread_kill() and pthread_sigmask() to signal.h. In principle, this shouldn't break anything, since they're already in signal.h on other systems, and the FreeBSD manpage says that both pthread.h and signal.h need to be included to get these functions. Add a hack to declare pthread_t in the P1003.1-2008 namespace in signal.h.
2009-03-14 20:10:14 +00:00
#if __POSIX_VISIBLE || __XSI_VISIBLE
struct pthread; /* XXX */
typedef struct pthread *__pthread_t;
#if !defined(_PTHREAD_T_DECLARED) && __POSIX_VISIBLE >= 200809
typedef __pthread_t pthread_t;
#define _PTHREAD_T_DECLARED
#endif
#endif /* __POSIX_VISIBLE || __XSI_VISIBLE */
BSD 4.4 Lite Include Sources
1994-05-24 09:57:34 +00:00
__BEGIN_DECLS
Breath deep and take __P out of the system include files. # This appears to not break X11, but I'm having problems compiling the # glide part of the server with or without this patch, so I can't tell # for sure.
2002-03-23 17:24:55 +00:00
int raise(int);
o Use relatively new visibility primitives from <sys/cdefs.h>. o Add typedef for pid_t. o Add comment about missing restrict type-qualifier. o Remove unneeded includes (<sys/_posix.h> and <sys/time.h>).
2002-10-06 21:54:08 +00:00
Assume POSIX/XSI is always visible in the __BSD_VISIBLE case. Fix a mix-up with siginterrupt().
2002-10-13 00:29:06 +00:00
#if __POSIX_VISIBLE || __XSI_VISIBLE
o Merge <machine/ansi.h> and <machine/types.h> into a new header called <machine/_types.h>. o <machine/ansi.h> will continue to live so it can define MD clock macros, which are only MD because of gratuitous differences between architectures. o Change all headers to make use of this. This mainly involves changing: #ifdef _BSD_FOO_T_ typedef _BSD_FOO_T_ foo_t; #undef _BSD_FOO_T_ #endif to: #ifndef _FOO_T_DECLARED typedef __foo_t foo_t; #define _FOO_T_DECLARED #endif Concept by: bde Reviewed by: jake, obrien
2002-08-21 16:20:02 +00:00
int kill(__pid_t, int);
Fix the visibility of several prototypes. Also move pthread_kill() and pthread_sigmask() to signal.h. In principle, this shouldn't break anything, since they're already in signal.h on other systems, and the FreeBSD manpage says that both pthread.h and signal.h need to be included to get these functions. Add a hack to declare pthread_t in the P1003.1-2008 namespace in signal.h.
2009-03-14 20:10:14 +00:00
int pthread_kill(__pthread_t, int);
Add restrict keyword to pthread_sigmask prototype and manpage. MFC after: 1 week
2011-02-20 09:52:29 +00:00
int pthread_sigmask(int, const __sigset_t * __restrict,
__sigset_t * __restrict);
Add the 'restrict' type qualifier to the prototypes of `sigaction', `sigprocmask', `sigaltstack', and `sigwait' as well as to the prototypes of the apparantly unimplemented functions `sigtimedwait' and `sigwaitinfo'. This complies with IEEE Std 1003.1-2001.
2002-10-02 10:53:44 +00:00
int sigaction(int, const struct sigaction * __restrict,
struct sigaction * __restrict);
Breath deep and take __P out of the system include files. # This appears to not break X11, but I'm having problems compiling the # glide part of the server with or without this patch, so I can't tell # for sure.
2002-03-23 17:24:55 +00:00
int sigaddset(sigset_t *, int);
int sigdelset(sigset_t *, int);
int sigemptyset(sigset_t *);
int sigfillset(sigset_t *);
int sigismember(const sigset_t *, int);
Make use of clang nullability attributes. Replace uses of the GCC __nonnull__ attribute with the clang nullability qualifiers. The replacement should be transparent for clang developers as the new qualifiers will produce the same warnings and will be useful for static checkers but will not cause aggressive optimizations. GCC will not produce such warnings and developers will have to use upgraded GCC ports built with the system headers from r312538. Hinted by: Apple's Libc-1158.20.4, Bionic libc MFC after: 11.1 Release Differential Revision: https://reviews.freebsd.org/D9004
2017-01-28 20:54:43 +00:00
int sigpending(sigset_t * _Nonnull);
Add the 'restrict' type qualifier to the prototypes of `sigaction', `sigprocmask', `sigaltstack', and `sigwait' as well as to the prototypes of the apparantly unimplemented functions `sigtimedwait' and `sigwaitinfo'. This complies with IEEE Std 1003.1-2001.
2002-10-02 10:53:44 +00:00
int sigprocmask(int, const sigset_t * __restrict, sigset_t * __restrict);
Make use of clang nullability attributes. Replace uses of the GCC __nonnull__ attribute with the clang nullability qualifiers. The replacement should be transparent for clang developers as the new qualifiers will produce the same warnings and will be useful for static checkers but will not cause aggressive optimizations. GCC will not produce such warnings and developers will have to use upgraded GCC ports built with the system headers from r312538. Hinted by: Apple's Libc-1158.20.4, Bionic libc MFC after: 11.1 Release Differential Revision: https://reviews.freebsd.org/D9004
2017-01-28 20:54:43 +00:00
int sigsuspend(const sigset_t * _Nonnull);
int sigwait(const sigset_t * _Nonnull __restrict,
int * _Nonnull __restrict);
o Use relatively new visibility primitives from <sys/cdefs.h>. o Add typedef for pid_t. o Add comment about missing restrict type-qualifier. o Remove unneeded includes (<sys/_posix.h> and <sys/time.h>).
2002-10-06 21:54:08 +00:00
#endif
Reviewed by: bde Changes to support building with _POSIX_SOURCE set to 199309L: 1. Add sys/_posix.h to handle those preprocessor defs that POSIX says have effects when defined before including any header files; 2. Change POSIX4_VISIBLE back to _POSIX4_VISIBLE 3. Add _POSIX4_VISIBLE_HISTORICALLY for pre-existing BSD features now defined in POSIX. These show up when: _POSIX_SOURCE and _POSIX_C_SOURCE are not set or _POSIX_C_SOURCE is set >= 199309L and vanish when: _POSIX_SOURCE is set or _POSIX_C_SOURCE is < 199309L. 4. Explain these in man 9 posix4; 5. Include _posix.h and conditionalize on new feature test.
1998-03-08 17:25:38 +00:00
Assume POSIX/XSI is always visible in the __BSD_VISIBLE case. Fix a mix-up with siginterrupt().
2002-10-13 00:29:06 +00:00
#if __POSIX_VISIBLE >= 199506 || __XSI_VISIBLE >= 600
Use __pid_t instead of pid_t for sigqueue as other functions.
2005-10-16 22:23:03 +00:00
int sigqueue(__pid_t, int, const union sigval);
Add sigqueue function prototype.
2005-10-14 13:12:27 +00:00
o Move forward declaration for struct timespec to a more appropriate location. o Don't prototype functions for which we don't have an implementation. o Add forward declaration for struct __ucontext, previously this was forward declared in <sys/signal.h>. o Add a comment about the size of NSIG. PR: 35924 Submitted by: bde
2002-10-14 14:13:37 +00:00
struct timespec;
o Use relatively new visibility primitives from <sys/cdefs.h>. o Add typedef for pid_t. o Add comment about missing restrict type-qualifier. o Remove unneeded includes (<sys/_posix.h> and <sys/time.h>).
2002-10-06 21:54:08 +00:00
int sigtimedwait(const sigset_t * __restrict, siginfo_t * __restrict,
Add the 'restrict' type qualifier to the prototypes of `sigaction', `sigprocmask', `sigaltstack', and `sigwait' as well as to the prototypes of the apparantly unimplemented functions `sigtimedwait' and `sigwaitinfo'. This complies with IEEE Std 1003.1-2001.
2002-10-02 10:53:44 +00:00
const struct timespec * __restrict);
o Use relatively new visibility primitives from <sys/cdefs.h>. o Add typedef for pid_t. o Add comment about missing restrict type-qualifier. o Remove unneeded includes (<sys/_posix.h> and <sys/time.h>).
2002-10-06 21:54:08 +00:00
int sigwaitinfo(const sigset_t * __restrict, siginfo_t * __restrict);
Reviewed by: msmith, bde long ago POSIX.4 headers and sysctl variables. Nothing should change unless POSIX4 is defined or _POSIX_VERSION is set to 199309.
1998-03-04 10:27:00 +00:00
#endif
o Use relatively new visibility primitives from <sys/cdefs.h>. o Add typedef for pid_t. o Add comment about missing restrict type-qualifier. o Remove unneeded includes (<sys/_posix.h> and <sys/time.h>).
2002-10-06 21:54:08 +00:00
Assume POSIX/XSI is always visible in the __BSD_VISIBLE case. Fix a mix-up with siginterrupt().
2002-10-13 00:29:06 +00:00
#if __XSI_VISIBLE
o Merge <machine/ansi.h> and <machine/types.h> into a new header called <machine/_types.h>. o <machine/ansi.h> will continue to live so it can define MD clock macros, which are only MD because of gratuitous differences between architectures. o Change all headers to make use of this. This mainly involves changing: #ifdef _BSD_FOO_T_ typedef _BSD_FOO_T_ foo_t; #undef _BSD_FOO_T_ #endif to: #ifndef _FOO_T_DECLARED typedef __foo_t foo_t; #define _FOO_T_DECLARED #endif Concept by: bde Reviewed by: jake, obrien
2002-08-21 16:20:02 +00:00
int killpg(__pid_t, int);
Add the 'restrict' type qualifier to the prototypes of `sigaction', `sigprocmask', `sigaltstack', and `sigwait' as well as to the prototypes of the apparantly unimplemented functions `sigtimedwait' and `sigwaitinfo'. This complies with IEEE Std 1003.1-2001.
2002-10-02 10:53:44 +00:00
int sigaltstack(const stack_t * __restrict, stack_t * __restrict);
Don't name parameters, for consistency with the rest of the file, and because it breaks third-party apps. Submitted by: gahr
2009-12-22 22:15:52 +00:00
int sighold(int);
int sigignore(int);
int sigpause(int);
int sigrelse(int);
Make use of clang nullability attributes. Replace uses of the GCC __nonnull__ attribute with the clang nullability qualifiers. The replacement should be transparent for clang developers as the new qualifiers will produce the same warnings and will be useful for static checkers but will not cause aggressive optimizations. GCC will not produce such warnings and developers will have to use upgraded GCC ports built with the system headers from r312538. Hinted by: Apple's Libc-1158.20.4, Bionic libc MFC after: 11.1 Release Differential Revision: https://reviews.freebsd.org/D9004
2017-01-28 20:54:43 +00:00
void (* _Nullable sigset(int, void (* _Nullable)(int)))(int);
Don't name parameters, for consistency with the rest of the file, and because it breaks third-party apps. Submitted by: gahr
2009-12-22 22:15:52 +00:00
int xsi_sigpause(int);
o Use relatively new visibility primitives from <sys/cdefs.h>. o Add typedef for pid_t. o Add comment about missing restrict type-qualifier. o Remove unneeded includes (<sys/_posix.h> and <sys/time.h>).
2002-10-06 21:54:08 +00:00
#endif
Fix the visibility of several prototypes. Also move pthread_kill() and pthread_sigmask() to signal.h. In principle, this shouldn't break anything, since they're already in signal.h on other systems, and the FreeBSD manpage says that both pthread.h and signal.h need to be included to get these functions. Add a hack to declare pthread_t in the P1003.1-2008 namespace in signal.h.
2009-03-14 20:10:14 +00:00
#if __XSI_VISIBLE >= 600
Assume POSIX/XSI is always visible in the __BSD_VISIBLE case. Fix a mix-up with siginterrupt().
2002-10-13 00:29:06 +00:00
int siginterrupt(int, int);
#endif
include: Remove checks for __BSD_VISIBLE where redundant with __XSI_VISIBLE or __POSIX_VISIBLE. Whenever <sys/cdefs.h> sets __BSD_VISIBLE to non-zero, it also sets __POSIX_VISIBLE and __XSI_VISIBLE to the newest version supported. No functional change is intended.
2014-05-11 13:48:21 +00:00
#if __POSIX_VISIBLE >= 200809
Fix the signature of the psignal() function. POSIX 2008 added the psignal() function which has already been part of the BSDs for a long time. The only difference is, the POSIX version uses an 'int' for the signal number, unlike our version which uses an 'unsigned int'. Fix up the function to use an 'int'. This should not affect the ABI.
2016-05-30 13:51:27 +00:00
void psignal(int, const char *);
Add psignal to the POSIX.1-2008 namespace.
2009-03-04 03:32:56 +00:00
#endif
o Use relatively new visibility primitives from <sys/cdefs.h>. o Add typedef for pid_t. o Add comment about missing restrict type-qualifier. o Remove unneeded includes (<sys/_posix.h> and <sys/time.h>).
2002-10-06 21:54:08 +00:00
#if __BSD_VISIBLE
int sigblock(int);
Breath deep and take __P out of the system include files. # This appears to not break X11, but I'm having problems compiling the # glide part of the server with or without this patch, so I can't tell # for sure.
2002-03-23 17:24:55 +00:00
int sigreturn(const struct __ucontext *);
int sigsetmask(int);
int sigstack(const struct sigstack *, struct sigstack *);
int sigvec(int, struct sigvec *, struct sigvec *);
o Use relatively new visibility primitives from <sys/cdefs.h>. o Add typedef for pid_t. o Add comment about missing restrict type-qualifier. o Remove unneeded includes (<sys/_posix.h> and <sys/time.h>).
2002-10-06 21:54:08 +00:00
#endif
BSD 4.4 Lite Include Sources
1994-05-24 09:57:34 +00:00
__END_DECLS
Make use of clang nullability attributes. Replace uses of the GCC __nonnull__ attribute with the clang nullability qualifiers. The replacement should be transparent for clang developers as the new qualifiers will produce the same warnings and will be useful for static checkers but will not cause aggressive optimizations. GCC will not produce such warnings and developers will have to use upgraded GCC ports built with the system headers from r312538. Hinted by: Apple's Libc-1158.20.4, Bionic libc MFC after: 11.1 Release Differential Revision: https://reviews.freebsd.org/D9004
2017-01-28 20:54:43 +00:00
__NULLABILITY_PRAGMA_POP
BSD 4.4 Lite Include Sources
1994-05-24 09:57:34 +00:00
Fix standards conformance bugs in <signal.h>: include/signal.h: There was massive namespace pollution from including <sys/types.h>. POSIX functions were declared even when _ANSI_SOURCE is defined. sys.sys/signal.h: NSIG was declared even if _ANSI_SOURCE or _POSIX_SOURCE is defined. sig_atomic_t wasn't declared if _POSIX_SOURCE is defined. Declare a typedef for signal handling functions and use it to unobfuscate declarations and to avoid half-baked function types that cause unwanted compiler warnings at certain warning levels. Fix confusing comment about SA_RESTART. sys/i386/include/signal.h: This has to be included to get the declaration of sig_atomic_t even when _ANSI_SOURCE is defined, so be more careful about polluting the ANSI namespace. Uniformize idempotency ifdefs.
1995-06-28 02:14:13 +00:00
#endif /* !_SIGNAL_H_ */
Reference in New Issue Copy Permalink