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author | Ulrich Drepper <drepper@redhat.com> | 2001-04-07 20:09:42 +0000 |
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committer | Ulrich Drepper <drepper@redhat.com> | 2001-04-07 20:09:42 +0000 |
commit | 4ee87eccd95908f1804412f274ef8595fff376b7 (patch) | |
tree | 66edf1afb1c31bc6bdb8a30f79da64c31ccbf2b7 /sysdeps/unix/sysv/linux/i386/makecontext.S | |
parent | 71483c00a8fbc61b67592781f499708939e7c7c7 (diff) | |
download | glibc-4ee87eccd95908f1804412f274ef8595fff376b7.zip glibc-4ee87eccd95908f1804412f274ef8595fff376b7.tar.gz glibc-4ee87eccd95908f1804412f274ef8595fff376b7.tar.bz2 |
Update.
2001-04-07 Ulrich Drepper <drepper@redhat.com>
* sysdeps/unix/sysv/linux/i386/getcontext.S: New file.
* sysdeps/unix/sysv/linux/i386/setcontext.S: New file.
* sysdeps/unix/sysv/linux/i386/makecontext.S: New file.
* sysdeps/unix/sysv/linux/i386/swapcontext.S: New file.
* sysdeps/unix/sysv/linux/i386/ucontext_i.h: New file.
* sysdeps/unix/sysv/linux/i386/Dist: Add ucontext_i.h.
Diffstat (limited to 'sysdeps/unix/sysv/linux/i386/makecontext.S')
-rw-r--r-- | sysdeps/unix/sysv/linux/i386/makecontext.S | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/i386/makecontext.S b/sysdeps/unix/sysv/linux/i386/makecontext.S new file mode 100644 index 0000000..a68e66c --- /dev/null +++ b/sysdeps/unix/sysv/linux/i386/makecontext.S @@ -0,0 +1,113 @@ +/* Create new context. + Copyright (C) 2001 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@redhat.com>, 2001. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include <sysdep.h> + +#include "ucontext_i.h" + + +ENTRY(__makecontext) + movl 4(%esp), %eax + + /* Load the address of the function we are supposed to run. */ + movl 8(%esp), %ecx + + /* Compute the address of the stack. The information comes from + to us_stack element. */ + movl oSS_SP(%eax), %edx + movl %ecx, oEIP(%eax) + addl oSS_SIZE(%eax), %edx + + /* Put the next context on the new stack (from the uc_link + element). */ + movl oLINK(%eax), %ecx + movl %ecx, -4(%edx) + + /* Remember the number of parameters for the exit handler since + it has to remove them. We store the number in the EBX register + which the function we will call must preserve. */ + movl 12(%esp), %ecx + movl %ecx, oEBX(%eax) + + /* Make room on the new stack for the parameters. */ + negl %ecx + leal -8(%edx,%ecx,4), %edx + negl %ecx + /* Store the future stack pointer. */ + movl %edx, oESP(%eax) + + /* Copy all the parameters. */ + jecxz 2f +1: movl 12(%esp,%ecx,4), %eax + movl %eax, (%edx,%ecx,4) + decl %ecx + jnz 1b +2: + + /* If the function we call returns we must continue with the + context which is given in the uc_link element. To do this + set the return address for the function the user provides + to a little bit of helper code which does the magic (see + below). */ +#ifdef PIC + call 1f +1: popl %ecx + addl $L(exitcode)-1b, %ecx + movl %ecx, (%edx) +#else + movl $L(exitcode), (%edx) +#endif + /* 'makecontext' returns no value. */ + ret + + /* This is the helper code which gets called if a function which + is registered with 'makecontext' returns. In this case we + have to install the context listed in the uc_link element of + the context 'makecontext' manipulated at the time of the + 'makecontext' call. If the pointer is NULL the process must + terminate. */ +L(exitcode): + /* This removes the parameters passed to the function given to + 'makecontext' from the stack. EBX contains the number of + parameters (see above). */ + leal (%esp,%ebx,4), %esp + +#ifdef PIC + call 1f +1: popl %ebx + addl $_GLOBAL_OFFSET_TABLE_+[.-1b], %ebx +#endif + popl %eax /* This is the next context. */ + testl %eax, %eax + je 2f /* If it is zero exit. */ + + pushl %eax + call JUMPTARGET(__setcontext) + /* If this returns (which can happen if the syscall fails) we'll + exit the program with the return error value (-1). */ + +2: pushl %eax + call JUMPTARGET(exit) + /* The 'exit' call should never return. In case it does cause + the process to terminate. */ + hlt +END(__makecontext) + +weak_alias(__makecontext, makecontext) |