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authorRoland McGrath <roland@gnu.org>1995-07-10 09:40:15 +0000
committerRoland McGrath <roland@gnu.org>1995-07-10 09:40:15 +0000
commitd819080cbadbd4b820ba77fe8c9b5ed0cbbfe581 (patch)
treed6c0ef96e616a594bba04e704d0042365e5a77ab /sysdeps/mach/hurd/i386
parent1f4a4317e1bafb185a22951f7921af4f9673811e (diff)
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Mon Jul 10 05:39:21 1995 Roland McGrath <roland@churchy.gnu.ai.mit.edu>
* sysdeps/mach/hurd/i386/init-first.c (init): Take just one arg, DATA for the entry SP; DATA[-1] is always the return address location. In both cthreads and non-cthreads cases, use asm to force parameters into %eax and %ecx before return, and mutate DATA[-1] to return to specific asm code to set up the user from %eax and %ecx. [PIC] (_init): Caller changed. (__libc_init_first) [! PIC] (doinit): Use asm to effect call to init with SP unwound to argument data ptr. Thu Jul 6 14:28:56 1995 Roland McGrath <roland@churchy.gnu.ai.mit.edu> * sysdeps/mach/hurd/dl-sysdep.c (fmh): Fixed this kludge to work when 0x08000000 and up are not mapped. * Makerules (stamp$o-$(subdir) rule): Remove the timestamp file before touching it. (lib%.so): Use -Wl to get -soname to ld. * elf/dlsym.c: Pass final arg to _dl_lookup_symbol. * elf/Makefile (libdl.so): Pass $(LDFLAGS.so).
Diffstat (limited to 'sysdeps/mach/hurd/i386')
-rw-r--r--sysdeps/mach/hurd/i386/init-first.c85
1 files changed, 50 insertions, 35 deletions
diff --git a/sysdeps/mach/hurd/i386/init-first.c b/sysdeps/mach/hurd/i386/init-first.c
index 74b15c8f2f..a23d201e58 100644
--- a/sysdeps/mach/hurd/i386/init-first.c
+++ b/sysdeps/mach/hurd/i386/init-first.c
@@ -96,7 +96,7 @@ init1 (int argc, char *arg0, ...)
}
static void
-init (int *data, void *usercode, void **retaddrloc)
+init (int *data)
{
int argc = *data;
char **argv = (void *) (data + 1);
@@ -144,42 +144,43 @@ init (int *data, void *usercode, void **retaddrloc)
/* Push the user code address on the top of the new stack. It will
be the return address for `init1'; we will jump there with NEWSP
as the stack pointer. */
- *--(void **) newsp = usercode;
- /* Mutate our own return address to run the code below. */
- *retaddrloc = &&switch_stacks;
+ *--(int *) newsp = data[-1];
+ ((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" (&init1), "c" (newsp));
- return;
- 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 %ecx, %esp; jmp *%eax");
- /* NOTREACHED */
- }
+ by function return. */
+ asm volatile ("# a %0 c %1" : : "a" (newsp), "c" (&init1));
+ }
else
{
- /* We are not switching stacks, but we must play some games with
- the one we've got, similar to the stack-switching code above. */
- *retaddrloc = &&call_init1;
- /* Force the user code address into %ecx and the run-time address of
- `init1' into %eax, for use below. */
- asm volatile ("# a %0 c %1" : : "a" (&init1), "c" (usercode));
- return;
- 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 %ecx 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 %ecx; jmp *%eax");
- /* NOTREACHED */
+ /* The argument data is just above the stack frame we will unwind by
+ returning. Mutate our own return address to run the code below. */
+ int usercode = data[-1];
+ ((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;
+
+ 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 */
}
@@ -202,7 +203,7 @@ _init (int argc, ...)
RUN_HOOK (_hurd_preinit_hook, ());
- init (&argc, ((void **) &argc)[-1], &((void **) &argc)[-1]);
+ init (&argc);
}
#endif
@@ -213,7 +214,21 @@ __libc_init_first (int argc __attribute__ ((unused)), ...)
#ifndef PIC
void doinit (int *data)
{
- init (data, ((void **) &argc)[-1], &((void **) &data)[-1]);
+ /* This function gets called with the argument data at TOS. */
+ void doinit1 (int argc, ...)
+ {
+ init (&argc);
+ }
+
+ /* Push the user return address after the argument data, and then
+ jump to `doinit1' (above), so it is as if __libc_init_first's
+ caller had called `doinit1' with the argument data already on the
+ stack. */
+ *--data = (&argc)[-1];
+ asm volatile ("movl %0, %%esp\n" /* Switch to new outermost stack. */
+ "movl $0, %%ebp\n" /* Clear outermost frame pointer. */
+ "jmp *%1" : : "r" (data), "r" (&doinit1));
+ /* NOTREACHED */
}
/* Initialize data structures so we can do RPCs. */