Applied, thanks!
Sergey Bugaev, le sam. 18 févr. 2023 23:37:13 +0300, a ecrit:
> And make it a bit more 64-bit ready. This is in preparation to moving this
> file into x86/
>
> Signed-off-by: Sergey Bugaev <buga...@gmail.com>
> ---
> sysdeps/mach/hurd/i386/init-first.c | 23 +++++++----------------
> 1 file changed, 7 insertions(+), 16 deletions(-)
>
> diff --git a/sysdeps/mach/hurd/i386/init-first.c
> b/sysdeps/mach/hurd/i386/init-first.c
> index 94c94651..a558da16 100644
> --- a/sysdeps/mach/hurd/i386/init-first.c
> +++ b/sysdeps/mach/hurd/i386/init-first.c
> @@ -195,7 +195,7 @@ init (int *data)
> /* Call `init1' (above) with the user code as the return address, and the
> argument data immediately above that on the stack. */
>
> - int usercode;
> + void *usercode, **ret_address;
>
> void call_init1 (void);
>
> @@ -206,10 +206,11 @@ init (int *data)
> recognize that this read operation may alias the following write
> operation, and thus is free to reorder the two, clobbering the
> original return address. */
> - usercode = *((int *) __builtin_frame_address (0) + 1);
> + ret_address = (void **) __builtin_frame_address (0) + 1;
> + usercode = *ret_address;
> /* GCC 4.4.6 also wants us to force loading USERCODE already here. */
> asm volatile ("# %0" : : "X" (usercode));
> - *((void **) __builtin_frame_address (0) + 1) = &call_init1;
> + *ret_address = &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));
> @@ -223,19 +224,9 @@ init (int *data)
> /* 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:\n"
> - " movl %eax, %esp\n"
> - " 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. */
> + values we set just above. 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:\n"
> " push %eax\n"
> " jmp *%ecx\n");
> --
> 2.39.2
>
>
--
Samuel
---
Pour une évaluation indépendante, transparente et rigoureuse !
Je soutiens la Commission d'Évaluation de l'Inria.
