diff options
Diffstat (limited to 'sysdeps/unix/sysv')
| -rw-r--r-- | sysdeps/unix/sysv/linux/i386/swapcontext.S | 56 |
1 files changed, 22 insertions, 34 deletions
diff --git a/sysdeps/unix/sysv/linux/i386/swapcontext.S b/sysdeps/unix/sysv/linux/i386/swapcontext.S index e44e9301b0..d909e659e4 100644 --- a/sysdeps/unix/sysv/linux/i386/swapcontext.S +++ b/sysdeps/unix/sysv/linux/i386/swapcontext.S @@ -1,5 +1,5 @@ /* Save current context and install the given one. - Copyright (C) 2001, 2002 Free Software Foundation, Inc. + Copyright (C) 2001, 2002, 2003 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper <drepper@redhat.com>, 2001. @@ -78,43 +78,31 @@ ENTRY(__swapcontext) movl oFPREGS(%eax), %ecx fldenv (%ecx) - /* Restore the FS segment registers. */ + /* Restore the FS segment register. We don't touch the GS register + since it is used for threads. */ movl oFS(%eax), %edx movw %dx, %fs + /* Fetch the address to return to. */ + movl oEIP(%eax), %ecx + /* Load the new stack pointer. */ - movl oESP(%eax), %ecx - /* Make room for 8 registers and the return address. We will load - the values from the stack. */ - subl $36, %ecx - - /* Move the values of all the 32-bit registers (except ESP) on - the stack. This happens in the form the 'popa' instruction - expects it. Before this block put the address of the code - to execute. */ - movl oEDI(%eax), %ebx - movl oESI(%eax), %edx - movl oEBP(%eax), %esi - movl oEBX(%eax), %edi - movl %ebx, (%ecx) - movl %edx, 4(%ecx) - movl %esi, 8(%ecx) - movl %edi, 16(%ecx) - movl oEDX(%eax), %ebx - movl oECX(%eax), %edx - movl oEAX(%eax), %esi - movl oEIP(%eax), %edi - movl %ebx, 20(%ecx) - movl %edx, 24(%ecx) - movl %esi, 28(%ecx) - movl %edi, 32(%ecx) - - /* Set the new stack address. The stack points now to the block - we put the register content in. */ - movl %ecx, %esp - /* Restore the register content. */ - popa - /* The following 'ret' will pop the addres of the code and jump + movl oESP(%eax), %esp + + /* Push the return address on the new stack so we can return there. */ + pushl %ecx + + /* Load the values of all the 32-bit registers (except ESP). + Since we are loading from EAX, it must be last. */ + movl oEDI(%eax), %edi + movl oESI(%eax), %esi + movl oEBP(%eax), %ebp + movl oEBX(%eax), %ebx + movl oEDX(%eax), %edx + movl oECX(%eax), %ecx + movl oEAX(%eax), %eax + + /* The following 'ret' will pop the address of the code and jump to it. */ L(pseudo_end): |