diff options
Diffstat (limited to 'sysdeps/mach/hurd/i386/init-first.c')
| -rw-r--r-- | sysdeps/mach/hurd/i386/init-first.c | 56 |
1 files changed, 33 insertions, 23 deletions
diff --git a/sysdeps/mach/hurd/i386/init-first.c b/sysdeps/mach/hurd/i386/init-first.c index c18b6a82ac..ee7b90252b 100644 --- a/sysdeps/mach/hurd/i386/init-first.c +++ b/sysdeps/mach/hurd/i386/init-first.c @@ -1,5 +1,5 @@ /* Initialization code run first thing by the ELF startup code. For i386/Hurd. - Copyright (C) 1995, 1996, 1997, 1998 Free Software Foundation, Inc. + Copyright (C) 1995, 96, 97, 98, 99 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 @@ -157,6 +157,8 @@ init (int *data) void *newsp = (*_cthread_init_routine) (); struct hurd_startup_data *od; + void switch_stacks (void); + /* Copy per-thread variables from that temporary area onto the new cthread stack. */ memcpy (__hurd_threadvar_location_from_sp (0, newsp), @@ -181,7 +183,7 @@ init (int *data) be the return address for `init1'; we will jump there with NEWSP as the stack pointer. */ *--(int *) newsp = data[-1]; - ((void **) data)[-1] = &&switch_stacks; + ((void **) data)[-1] = switch_stacks; /* Force NEWSP into %ecx and &init1 into %eax, which are not restored by function return. */ asm volatile ("# a %0 c %1" : : "a" (newsp), "c" (&init1)); @@ -194,6 +196,8 @@ init (int *data) unsigned int i; int usercode; + void call_init1 (void); + array = malloc (__hurd_threadvar_max * sizeof (unsigned long int)); if (array == NULL) __libc_fatal ("Can't allocate single-threaded thread variables."); @@ -208,33 +212,39 @@ init (int *data) /* The argument data is just above the stack frame we will unwind by returning. Mutate our own return address to run the code below. */ usercode = data[-1]; - ((void **) data)[-1] = &&call_init1; + ((void **) data)[-1] = call_init1; /* Force USERCODE into %eax and &init1 into %ecx, which are not restored by function return. */ asm volatile ("# a %0 c %1" : : "a" (usercode), "c" (&init1)); } +} - return; - +/* These bits of inline assembler used to be located inside `init'. + However they were optimized away by gcc 2.95. */ + +/* The return address of `init' above, was redirected to here, so at + this point our stack is unwound and callers' registers restored. + Only %ecx and %eax are call-clobbered and thus still have the + values we set just above. Fetch from there the new stack pointer + we will run on, and jmp to the run-time address of `init1'; when it + returns, it will run the user code with the argument data at the + top of the stack. */ +asm (" switch_stacks: - /* Our return address was redirected to here, so at this point our stack - is unwound and callers' registers restored. Only %ecx and %eax are - call-clobbered and thus still have the values we set just above. - Fetch from there the new stack pointer we will run on, and jmp to the - run-time address of `init1'; when it returns, it will run the user - code with the argument data at the top of the stack. */ - asm volatile ("movl %eax, %esp; jmp *%ecx"); - /* NOTREACHED */ - - call_init1: - /* As in the stack-switching case, at this point our stack is unwound and - callers' registers restored, and only %ecx and %eax communicate values - from the lines above. In this case we have stashed in %eax the user - code return address. Push it on the top of the stack so it acts as - init1's return address, and then jump there. */ - asm volatile ("pushl %eax; jmp *%ecx"); - /* NOTREACHED */ -} + movl %eax, %esp + jmp *%ecx +"); + +/* As in the stack-switching case, at this point our stack is unwound + and callers' registers restored, and only %ecx and %eax communicate + values from the lines above. In this case we have stashed in %eax + the user code return address. Push it on the top of the stack so + it acts as init1's return address, and then jump there. */ +asm (" + call_init1: + push %eax + jmp *%ecx +"); #ifdef PIC |