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author | Andreas Jaeger <aj@suse.de> | 2002-08-31 08:04:45 +0000 |
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committer | Andreas Jaeger <aj@suse.de> | 2002-08-31 08:04:45 +0000 |
commit | ba1e2fe668361bd6887f237f70f47def96fa7bef (patch) | |
tree | 936c625a11b1cd7ebfecbc4d82d6673fd9c70806 /sysdeps/unix/sysv/linux/x86_64 | |
parent | cc6d371de3af78fa6440c9f80d441e7c73115f23 (diff) | |
download | glibc-ba1e2fe668361bd6887f237f70f47def96fa7bef.tar.gz glibc-ba1e2fe668361bd6887f237f70f47def96fa7bef.tar.xz glibc-ba1e2fe668361bd6887f237f70f47def96fa7bef.zip |
Linux/x86-64 makecontext implementation.
Diffstat (limited to 'sysdeps/unix/sysv/linux/x86_64')
-rw-r--r-- | sysdeps/unix/sysv/linux/x86_64/makecontext.c | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/x86_64/makecontext.c b/sysdeps/unix/sysv/linux/x86_64/makecontext.c new file mode 100644 index 0000000000..f859160a20 --- /dev/null +++ b/sysdeps/unix/sysv/linux/x86_64/makecontext.c @@ -0,0 +1,113 @@ +/* Create new context. + Copyright (C) 2002 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Andreas Jaeger <aj@suse.de>, 2002. + + 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <sysdep.h> +#include <stdarg.h> +#include <ucontext.h> + +#include "ucontext_i.h" + +/* This implementation can handle any ARGC value but only + normal integer parameters. + makecontext sets up a stack and the registers for the + user context. The stack looks like this: + +-----------------------+ + | next context | + +-----------------------+ + | parameter 7-n | + +-----------------------+ + | trampoline address | + %rsp -> +-----------------------+ + + The registers are set up like this: + %rdi,%rsi,%rdx,%rcx,%r8,%r9: parameter 1 to 6 + %rbx : address of next context + %rsp : stack pointer. +*/ + +/* XXX: This implementation currently only handles integer arguments. + To handle long int and pointer arguments the va_arg arguments needs + to be changed to long and also the stdlib/tst-setcontext.c file needs + to be changed to pass long arguments to makecontext. */ + + +void +__makecontext (ucontext_t *ucp, void (*func) (void), int argc, ...) +{ + extern void __start_context (void); + unsigned long *sp, idx_uc_link; + va_list ap; + int i; + + /* Generate room on stack for parameter if needed and uc_link. */ + sp = (long *) ((long) ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size); + sp -= (argc > 6 ? argc : 0) + 1; + /* Align stack. */ + sp = (long *) (((long) sp) & -16L); + /* Make space for trampoline address. */ + sp -= 8; + + idx_uc_link = (argc > 6 ? argc : 0) + 1; + + /* Setup context ucp. */ + /* Address to jump to. */ + ucp->uc_mcontext.gregs[REG_RIP] = (long) func; + /* Setup rbx.*/ + ucp->uc_mcontext.gregs[REG_RBX] = (long) &sp[idx_uc_link]; + ucp->uc_mcontext.gregs[REG_RSP] = (long) sp; + + /* Setup stack. */ + sp[0] = (long) &__start_context; + sp[idx_uc_link] = (long) ucp->uc_link; + + va_start (ap, argc); + /* Handle arguments. */ + for (i = 0; i < argc; ++i) + switch (i) + { + case 0: + ucp->uc_mcontext.gregs [REG_RDI] = va_arg (ap, int); + break; + case 1: + ucp->uc_mcontext.gregs [REG_RSI] = va_arg (ap, int); + break; + case 2: + ucp->uc_mcontext.gregs [REG_RDX] = va_arg (ap, int); + break; + case 3: + ucp->uc_mcontext.gregs [REG_RCX] = va_arg (ap, int); + break; + case 4: + ucp->uc_mcontext.gregs [REG_R8] = va_arg (ap, int); + break; + case 5: + ucp->uc_mcontext.gregs [REG_R9] = va_arg (ap, int); + break; + default: + /* Put value on stack. */ + sp[8 + (i - 5)] = va_arg (ap, int); + break; + } + va_end (ap); + +} + + +weak_alias(__makecontext, makecontext) |