glibc/sysdeps/unix/sysv/linux/nios2/makecontext.c
Paul Eggert 581c785bf3 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.

I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah.  I don't
know why I run into these diagnostics whereas others evidently do not.

remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
2022-01-01 11:40:24 -08:00

80 lines
2.4 KiB
C

/* Create new context.
Copyright (C) 2015-2022 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 <sysdep.h>
#include <stdarg.h>
#include <stdint.h>
#include <ucontext.h>
/* makecontext sets up a stack and the registers for the
user context. The stack looks like this:
+-----------------------+
| padding as required |
+-----------------------+
sp -> | parameters 5 to n |
+-----------------------+
The registers are set up like this:
r4--r7 : parameter 1 to 4
r16 : uc_link
sp : stack pointer.
*/
void
__makecontext (ucontext_t *ucp, void (*func) (void), int argc, ...)
{
extern void __startcontext (void);
unsigned long *sp;
va_list ap;
int i;
sp = (unsigned long *)
((uintptr_t) ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size);
/* Allocate stack arguments. */
sp -= argc < 4 ? 0 : argc - 4;
/* Keep the stack aligned. */
sp = (unsigned long*) (((uintptr_t) sp) & -4L);
/* Init version field. */
ucp->uc_mcontext.version = 2;
/* Keep uc_link in r16. */
ucp->uc_mcontext.regs[15] = (uintptr_t) ucp->uc_link;
/* Return address points to __startcontext(). */
ucp->uc_mcontext.regs[23] = (uintptr_t) &__startcontext;
/* Frame pointer is null. */
ucp->uc_mcontext.regs[24] = (uintptr_t) 0;
/* Restart in user-space starting at 'func'. */
ucp->uc_mcontext.regs[27] = (uintptr_t) func;
/* Set stack pointer. */
ucp->uc_mcontext.regs[28] = (uintptr_t) sp;
va_start (ap, argc);
for (i = 0; i < argc; ++i)
if (i < 4)
ucp->uc_mcontext.regs[i + 3] = va_arg (ap, unsigned long);
else
sp[i - 4] = va_arg (ap, unsigned long);
va_end (ap);
}
weak_alias (__makecontext, makecontext)