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Diffstat (limited to 'static/freebsd/man2/sigreturn.2')
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diff --git a/static/freebsd/man2/sigreturn.2 b/static/freebsd/man2/sigreturn.2 new file mode 100644 index 00000000..0e7bca50 --- /dev/null +++ b/static/freebsd/man2/sigreturn.2 @@ -0,0 +1,94 @@ +.\" Copyright (c) 1985, 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. +.\" 3. Neither the name of the University nor the names of its contributors +.\" 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. +.\" +.Dd March 11, 2026 +.Dt SIGRETURN 2 +.Os +.Sh NAME +.Nm sigreturn +.Nd return from signal +.Sh LIBRARY +.Lb libc +.Sh SYNOPSIS +.In signal.h +.Ft int +.Fn sigreturn "const ucontext_t *scp" +.Sh DESCRIPTION +The +.Fn sigreturn +system call +allows users to atomically unmask, switch stacks, +and return from a signal context. +The thread's signal mask and stack status are +restored from the context structure pointed to by +.Fa scp . +The system call does not return; +the whole userspace context as specified by +.Fa scp , +including the userspace stack pointer, all general-purpose registers, +coprocessor state, process status register, and program counter +are restored from the context. +Execution resumes at the program counter from the specified context. +.Pp +This system call is used by the kernel-provided signal trampoline code, +located in the virtual DSO (VDSO) on some architectures or as raw code +in the shared page if VDSO is not provided, +when returning from a signal to the previously executing program. +.Sh RETURN VALUES +If successful, the system call does not return. +Otherwise, a value of -1 may be returned, with +.Va errno +set to indicate the error. +Some conditions detected by hardware result in the delivery of +a synchronous trap signal to the thread, in addition to or instead of +setting the system call error code. +.Sh ERRORS +The +.Fn sigreturn +system call +will fail and the thread context will remain unchanged +if one of the following occurs. +.Bl -tag -width Er +.It Bq Er EFAULT +The +.Fa scp +argument +points to memory that is not a valid part of the process +address space. +.It Bq Er EINVAL +The process status longword is invalid or would improperly +raise the privilege level of the process. +.El +.Sh SEE ALSO +.Xr sigaction 2 , +.Xr setjmp 3 , +.Xr ucontext 3 +.Sh HISTORY +The +.Fn sigreturn +system call appeared in +.Bx 4.3 . |
