musl/src/signal/siglongjmp.c

#include <setjmp.h>
#include <signal.h>
#include <stdlib.h>
#include "syscall.h"

_Noreturn void siglongjmp(sigjmp_buf buf, int ret)
{
	if (buf->__fl) __syscall(SYS_rt_sigprocmask, SIG_SETMASK,
		buf->__ss, 0, _NSIG/8);
	longjmp(buf->__jb, ret);
}
initial check-in, version 0.5.0 2011-02-12 00:22:29 -05:00			`#include <setjmp.h>`
			`#include <signal.h>`
			`#include <stdlib.h>`
jmp_buf overhaul fixing several issues on arm, the location of the saved-signal-mask flag and mask were off by one between sigsetjmp and siglongjmp, causing incorrect behavior restoring the signal mask. this is because the siglongjmp code assumed an extra slot was in the non-sig jmp_buf for the flag, but arm did not have this. now, the extra slot is removed for all archs since it was useless. also, arm eabi requires jmp_buf to have 8-byte alignment. we achieve that using long long as the type rather than with non-portable gcc attribute tags. 2012-07-03 20:07:33 -04:00			`#include "syscall.h"`
initial check-in, version 0.5.0 2011-02-12 00:22:29 -05:00
further use of _Noreturn, for non-plain-C functions note that POSIX does not specify these functions as _Noreturn, because POSIX is aligned with C99, not the new C11 standard. when POSIX is eventually updated to C11, it will almost surely give these functions the _Noreturn attribute. for now, the actual _Noreturn keyword is not used anyway when compiling with a c99 compiler, which is what POSIX requires; the GCC __attribute__ is used instead if it's available, however. in a few places, I've added infinite for loops at the end of _Noreturn functions to silence compiler warnings. presumably __buildin_unreachable could achieve the same thing, but it would only work on newer GCCs and would not be portable. the loops should have near-zero code size cost anyway. like the previous _Noreturn commit, this one is based on patches contributed by philomath. 2012-09-06 23:34:10 -04:00			`_Noreturn void siglongjmp(sigjmp_buf buf, int ret)`
initial check-in, version 0.5.0 2011-02-12 00:22:29 -05:00			`{`
fix (hopefully) all hard-coded 8's for kernel sigset_t size some minor changes to how hard-coded sets for thread-related purposes are handled were also needed, since the old object sizes were not necessarily sufficient. things have gotten a bit ugly in this area, and i think a cleanup is in order at some point, but for now the goal is just to get the code working on all supported archs including mips, which was badly broken by linux rejecting syscalls with the wrong sigset_t size. 2012-08-09 22:52:13 -04:00			`if (buf->__fl) __syscall(SYS_rt_sigprocmask, SIG_SETMASK,`
remove __SYSCALL_SSLEN arch macro in favor of using public _NSIG the issue at hand is that many syscalls require as an argument the kernel-ABI size of sigset_t, intended to allow the kernel to switch to a larger sigset_t in the future. previously, each arch was defining this size in syscall_arch.h, which was redundant with the definition of _NSIG in bits/signal.h. as it's used in some not-quite-portable application code as well, _NSIG is much more likely to be recognized and understood immediately by someone reading the code, and it's also shorter and less cluttered. note that _NSIG is actually 65/129, not 64/128, but the division takes care of throwing away the off-by-one part. 2013-03-26 23:07:31 -04:00			`buf->__ss, 0, _NSIG/8);`
jmp_buf overhaul fixing several issues on arm, the location of the saved-signal-mask flag and mask were off by one between sigsetjmp and siglongjmp, causing incorrect behavior restoring the signal mask. this is because the siglongjmp code assumed an extra slot was in the non-sig jmp_buf for the flag, but arm did not have this. now, the extra slot is removed for all archs since it was useless. also, arm eabi requires jmp_buf to have 8-byte alignment. we achieve that using long long as the type rather than with non-portable gcc attribute tags. 2012-07-03 20:07:33 -04:00			`longjmp(buf->__jb, ret);`
initial check-in, version 0.5.0 2011-02-12 00:22:29 -05:00			`}`