diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/aarch64/makecontext.c')
-rw-r--r-- | sysdeps/unix/sysv/linux/aarch64/makecontext.c | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/aarch64/makecontext.c b/sysdeps/unix/sysv/linux/aarch64/makecontext.c new file mode 100644 index 0000000..806eab2 --- /dev/null +++ b/sysdeps/unix/sysv/linux/aarch64/makecontext.c @@ -0,0 +1,74 @@ +/* Create new context. + Copyright (C) 2002-2014 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 + <http://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 -> | parameter 7-n | + +-----------------------+ + + The registers are set up like this: + %x0 .. %x7: parameter 1 to 8 + %x19 : uc_link + %sp : stack pointer. +*/ + +void +__makecontext (ucontext_t *ucp, void (*func) (void), int argc, ...) +{ + extern void __startcontext (void); + unsigned long int *sp; + va_list ap; + int i; + + sp = (unsigned long int *) + ((uintptr_t) ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size); + + /* Allocate stack arguments. */ + sp -= argc < 8 ? 0 : argc - 8; + + /* Keep the stack aligned. */ + sp = (unsigned long int *) (((uintptr_t) sp) & -16L); + + ucp->uc_mcontext.regs[19] = (uintptr_t) ucp->uc_link; + ucp->uc_mcontext.sp = (uintptr_t) sp; + ucp->uc_mcontext.pc = (uintptr_t) func; + ucp->uc_mcontext.regs[29] = (uintptr_t) 0; + ucp->uc_mcontext.regs[30] = (uintptr_t) &__startcontext; + + va_start (ap, argc); + for (i = 0; i < argc; ++i) + if (i < 8) + ucp->uc_mcontext.regs[i] = va_arg (ap, unsigned long int); + else + sp[i - 8] = va_arg (ap, unsigned long int); + + va_end (ap); +} + +weak_alias (__makecontext, makecontext) |