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15254 %ymm registers not restored after signal handler
15367 x86 getfpregs() summons corrupting %xmm ghosts
15333 want x86 /proc xregs support (libc_db, libproc, mdb, etc.)
15336 want libc functions for extended ucontext_t
15334 want ps_lwphandle-specific reg routines
15328 FPU_CW_INIT mistreats reserved bit
15335 i86pc fpu_subr.c isn't really platform-specific
15332 setcontext(2) isn't actually noreturn
15331 need <sys/stdalign.h>
Change-Id: I7060aa86042dfb989f77fc3323c065ea2eafa9ad
Conflicts:
usr/src/uts/common/fs/proc/prcontrol.c
usr/src/uts/intel/os/archdep.c
usr/src/uts/intel/sys/ucontext.h
usr/src/uts/intel/syscall/getcontext.c
*** 41,130 ****
.\"
.\"
.\" Copyright 1989 AT&T
.\" Portions Copyright (c) 1992, X/Open Company Limited. All Rights Reserved.
.\" Copyright (c) 2004, Sun Microsystems, Inc. All Rights Reserved.
.\"
! .TH MAKECONTEXT 3C "February 17, 2023"
! .SH NAME
! makecontext, swapcontext \- manipulate user contexts
! .SH SYNOPSIS
! .nf
! #include <ucontext.h>
!
! \fBvoid\fR \fBmakecontext\fR(\fBucontext_t *\fR\fIucp\fR, \fBvoid (*\fR\fIfunc\fR)(), \fBint\fR \fIargc\fR...);
! .fi
!
! .LP
! .nf
! \fBint\fR \fBswapcontext\fR(\fBucontext_t *restrict\fR \fIoucp\fR,
! \fBconst ucontext_t *restrict\fR \fIucp\fR);
! .fi
!
! .SH DESCRIPTION
! The \fBmakecontext()\fR function modifies the context specified by \fIucp\fR,
! which has been initialized using \fBgetcontext\fR(2). When this context is
! resumed using \fBswapcontext()\fR or \fBsetcontext\fR(2), execution continues
! by calling the function \fIfunc\fR, passing it the arguments that follow
! \fIargc\fR in the \fBmakecontext()\fR call. The value of \fIargc\fR must match
! the number of pointer-sized integer arguments passed to \fIfunc\fR, otherwise
! the behavior is undefined.
! .sp
! .LP
! Before a call is made to \fBmakecontext()\fR, the context being modified should
! have a stack allocated for it. The stack is assigned to the context by
! initializing the \fBuc_stack\fR member.
! .sp
! .LP
! The \fBuc_link\fR member is used to determine the context that will be resumed
! when the context being modified by \fBmakecontext()\fR returns. The
! \fBuc_link\fR member should be initialized prior to the call to
! \fBmakecontext()\fR. If the \fBuc_link\fR member is initialized to \fINULL\fR,
! the thread executing \fIfunc\fR will exit when \fIfunc\fR returns. See
! \fBpthread_exit\fR(3C).
! .sp
! .LP
! The \fBswapcontext()\fR function saves the current context in the context
! structure pointed to by \fIoucp\fR and sets the context to the context
! structure pointed to by \fIucp\fR.
! .sp
! .LP
! If the \fIucp\fR or \fIoucp\fR argument points to an invalid address, the
! behavior is undefined and \fBerrno\fR may be set to \fBEFAULT\fR.
! .SH RETURN VALUES
! On successful completion, \fBswapcontext()\fR returns \fB0\fR. Otherwise,
! \fB\(mi1\fR is returned and \fBerrno\fR is set to indicate the error.
! .SH ERRORS
! The \fBswapcontext()\fR function will fail if:
! .sp
! .ne 2
! .na
! \fB\fBENOMEM\fR\fR
! .ad
! .RS 10n
! The \fIucp\fR argument does not have enough stack left to complete the
! operation.
! .RE
!
! .sp
! .LP
! The \fBswapcontext()\fR function may fail if:
! .sp
! .ne 2
! .na
! \fB\fBEFAULT\fR\fR
! .ad
! .RS 10n
! The \fIucp\fR or \fIoucp\fR argument points to an invalid address.
! .RE
!
! .SH EXAMPLES
! \fBExample 1 \fRAlternate execution context on a stack whose memory was
! allocated using \fBmmap()\fR.
! .sp
! .in +2
! .nf
#include <stdio.h>
#include <ucontext.h>
#include <sys/mman.h>
void
--- 41,188 ----
.\"
.\"
.\" Copyright 1989 AT&T
.\" Portions Copyright (c) 1992, X/Open Company Limited. All Rights Reserved.
.\" Copyright (c) 2004, Sun Microsystems, Inc. All Rights Reserved.
+ .\" Copyright 2023 Oxide Computer Company
.\"
! .Dd March 20, 2023
! .Dt MAKECONTEXT 3C
! .Os
! .Sh NAME
! .Nm makecontext ,
! .Nm swapcontext ,
! .Nm swapcontext_extd
! .Nd manipulate user contexts
! .Sh SYNOPSIS
! .In ucontext.h
! .Ft void
! .Fo makecontext
! .Fa "ucontext_t *ucp"
! .Fa "void (*ifunc)()"
! .Fa "int argc"
! .Fa "..."
! .Fc
! .Ft int
! .Fo swapcontext
! .Fa "ucontext_t *restrict oucp"
! .Fa "const ucontext_t *restrict ucp"
! .Fc
! .Ft int
! .Fo swapcontext_extd
! .Fa "ucontext_t *restrict oucp"
! .Fa "uint32_t flags"
! .Fa "const ucontext_t *restrict ucp"
! .Fc
! .Sh DESCRIPTION
! The
! .Fn makecontext
! function modifies the context specified by
! .Fa ucp ,
! which has been initialized using
! .Xr getcontext 2 or
! .Xr getcontext_extd 2 .
! When this context is resumed using
! .Fn swapcontext ,
! .Fn swapcontext_extd ,
! or
! .Xr setcontext 2 ,
! execution continues by calling the function
! .Fa func ,
! passing it the arguments that follow
! .Fa argc
! in the
! .Fn makecontext
! call.
! The value of
! .Fa argc
! must match the number of pointer-sized integer arguments passed to
! .Fa func ,
! otherwise the behavior is undefined.
! .Pp
! Before a call is made to
! .Fn makecontext ,
! the context being modified should have a stack allocated for it.
! The stack is assigned to the context by initializing the
! .Fa uc_stack
! member.
! .Pp
! The
! .Fa uc_link
! member is used to determine the context that will be resumed when the context
! being modified by
! .Fn makecontext
! returns.
! The
! .Fa uc_link
! member should be initialized prior to the call to
! .Fn makecontext .
! If the
! .Fa uc_link
! member is initialized to
! .Dv NULL ,
! the thread executing
! .Fa func
! will exit when
! .Fa func returns.
! See
! .Xr pthread_exit 3C .
! .Pp
! The
! .Fn swapcontext
! function saves the current context in the context structure pointed to by
! .Fa oucp
! and sets the context to the context structure pointed to by
! .Fa ucp .
! .Pp
! If the
! .Fa ucp
! or
! .Fa oucp
! argument points to an invalid address, the behavior is undefined and
! .Va errno
! may be set to
! .Er EFAULT .
! .Pp
! The
! .Fn swapcontext_extd
! function is similar to
! .Fn swapcontext
! except that it performs a call to
! .Xr getcontext_extd 2
! to get and save the current context, passing the
! .Fa flags
! argument to
! .Xr getcontext_extd 2 .
! Note, the same constraints around the initialization of the
! .Vt ucontext_t
! that are discussed in
! .Xr getcontext_extd 2
! still apply.
! Mainly, the context must either have originally come from
! .Xr ucontext_alloc 3C
! or prior to its first use been zeroed.
! See
! .Xr getcontext_extd 2
! for more information.
! .Sh RETURN VALUES
! On successful completion,
! .Fn swapcontext
! and
! .Fn swapcontext_extd
! return
! .Sy 0 .
! Otherwise,
! .Sy -1
! is returned and
! .Va errno
! is set to indicate the error.
! .Sh EXAMPLES
! .Sy Example 1
! Alternate execution context on a stack whose memory was allocated using
! .Fn mmap .
! .Bd -literal -offset 2
#include <stdio.h>
#include <ucontext.h>
#include <sys/mman.h>
void
*** 155,219 ****
printf("done %d\en", value);
return (0);
}
! .fi
! .in -2
!
! .SH USAGE
These functions are useful for implementing user-level context switching
! between multiple threads of control within a process (co-processing). More
! effective multiple threads of control can be obtained by using native support
! for multithreading. See \fBthreads\fR(7).
! .SH ATTRIBUTES
! See \fBattributes\fR(7) for descriptions of the following attributes:
! .sp
!
! .sp
! .TS
! box;
! c | c
! l | l .
! ATTRIBUTE TYPE ATTRIBUTE VALUE
! _
! Interface Stability Standard
! _
! MT-Level MT-Safe
! .TE
!
! .SH SEE ALSO
! .BR getcontext (2),
! .BR mmap (2),
! .BR sigaction (2),
! .BR sigprocmask (2),
! .BR pthread_exit (3C),
! .BR ucontext.h (3HEAD),
! .BR attributes (7),
! .BR standards (7),
! .BR threads (7)
! .SH NOTES
! The semantics of the \fBuc_stack\fR member of the \fBucontext_t\fR structure
! have changed as they apply to inputs to \fBmakecontext()\fR. Prior to Solaris
! 10, the \fBss_sp\fR member of the \fBuc_stack\fR structure represented the high
! memory address of the area reserved for the stack. The \fBss_sp\fR member now
! represents the base (low memory address), in keeping with other uses of
! \fBss_sp\fR.
! .sp
! .LP
! This change in the meaning of \fBss_sp\fR is now the default behavior. The
! \fB-D__MAKECONTEXT_V2_SOURCE\fR compilation flag used in Solaris 9 update
! releases to access this behavior is obsolete.
! .sp
! .LP
Binary compatibility has been preserved with releases prior to Solaris 10.
! Before recompiling, applications that use \fBmakecontext()\fR must be updated
! to reflect this behavior change. The example below demonstrates a typical change
! that must be applied:
! .sp
! .in +2
! .nf
--- example1_s9.c Thu Oct 3 11:58:17 2002
+++ example1.c Thu Jun 27 13:28:16 2002
@@ -27,12 +27,9 @@
uc.uc_stack.ss_sp = mmap(0, sz,
PROT_READ | PROT_WRITE | PROT_EXEC,
--- 213,311 ----
printf("done %d\en", value);
return (0);
}
! .Ed
! .Sh ERRORS
! The
! .Fn swapcontext
! and
! .Fn swapcontext_extd
! function will fail if:
! .Bl -tag -width Er
! .It Er ENOMEM
! The
! .Fa ucp
! argument does not have enough stack left to complete the operation.
! .El
! .Pp
! The
! .Fn swapcontext
! and
! .Fn swapcontext_extd
! functions may fail if:
! .Bl -tag -width Er
! .It Er EFAULT
! The
! .Fa ucp
! or
! .Fa oucp
! argument points to an invalid address.
! .El
! .Pp
! The
! .Fn swapcontext_extd
! function may additionally fail if:
! .Bl -tag -width Er
! .It Er EINVAL
! The
! .Fa flags
! argument contains invalid values.
! .El
! .Sh USAGE
These functions are useful for implementing user-level context switching
! between multiple threads of control within a process
! .Pq co-processing .
! More effective multiple threads of control can be obtained by using native
! support for multithreading.
! See
! .Xr threads 7 .
! .Sh INTERFACE STABILITY
! .Sy Committed
! .Sh MT-LEVEL
! .Sy MT-Safe
! .Sh SEE ALSO
! .Xr getcontext 2 ,
! .Xr getcontext_extd 2 ,
! .Xr mmap 2 ,
! .Xr sigaction 2 ,
! .Xr sigprocmask 2 ,
! .Xr pthread_exit 3C ,
! .Xr ucontext_alloc 3C ,
! .Xr ucontext.h 3HEAD ,
! .Xr attributes 7 ,
! .Xr standards 7 ,
! .Xr threads 7
! .Sh NOTES
! The semantics of the
! .Fa uc_stack
! member of the
! .Fa ucontext_t
! structure have changed as they apply to inputs to
! .Fn makecontext .
! Prior to Solaris 10, the
! .Fa ss_sp
! member of the
! .Fa uc_stack
! tructure represented the high memory address of the area reserved for the stack.
! The
! .Fa ss_sp
! member now represents the base
! .Pq low memory address ,
! in keeping with other uses of
! .Fa ss_sp .
! This change in the meaning of
! .Fa ss_sp
! is the default behavior.
! .Pp
Binary compatibility has been preserved with releases prior to Solaris 10.
! Before recompiling, applications that use
! .Fn makecontext
! must be updated to reflect this behavior change.
! The example below demonstrates a typical change that must be applied:
! .Bd -literal -offset 2
--- example1_s9.c Thu Oct 3 11:58:17 2002
+++ example1.c Thu Jun 27 13:28:16 2002
@@ -27,12 +27,9 @@
uc.uc_stack.ss_sp = mmap(0, sz,
PROT_READ | PROT_WRITE | PROT_EXEC,
*** 224,230 ****
uc.uc_link = &back
makecontext(&uc, assign, 2, 100L, &value);
.fi
! .in -2
!
--- 316,321 ----
uc.uc_link = &back
makecontext(&uc, assign, 2, 100L, &value);
.fi
! .Ed