Applied, thanks!
Sergey Bugaev, le lun. 26 juin 2023 02:17:47 +0300, a ecrit:
> Instead of trying to allocate a thread stack at a specific address,
> looping over the address space, just set the ANYWHERE flag in
> vm_allocate (). The previous behavior:
>
> - defeats ASLR (for Mach versions that support ASLR),
> - is particularly slow if the lower 4 GB of the address space are mapped
> inaccessible, as we're planning to do on 64-bit Hurd,
> - is just silly.
>
> Signed-off-by: Sergey Bugaev <buga...@gmail.com>
> ---
> sysdeps/mach/htl/pt-stack-alloc.c | 35 ++++++-------------------------
> 1 file changed, 6 insertions(+), 29 deletions(-)
>
> diff --git a/sysdeps/mach/htl/pt-stack-alloc.c
> b/sysdeps/mach/htl/pt-stack-alloc.c
> index 429ac2d9..97e6b445 100644
> --- a/sysdeps/mach/htl/pt-stack-alloc.c
> +++ b/sysdeps/mach/htl/pt-stack-alloc.c
> @@ -19,14 +19,9 @@
> #include <errno.h>
>
> #include <mach.h>
> -#include <mach/machine/vm_param.h>
>
> #include <pt-internal.h>
>
> -/* The next address to use for stack allocation. */
> -static vm_address_t next_stack_base = VM_MIN_ADDRESS;
> -
> -
> /* Allocate a new stack of size STACKSIZE. If successful, store the
> address of the newly allocated stack in *STACKADDR and return 0.
> Otherwise return an error code (EINVAL for an invalid stack size,
> @@ -35,30 +30,12 @@ static vm_address_t next_stack_base = VM_MIN_ADDRESS;
> int
> __pthread_stack_alloc (void **stackaddr, size_t stacksize)
> {
> - vm_offset_t base;
> - int i = 0;
> -
> -get_stack:
> - i++;
> - for (base = next_stack_base;
> - base < VM_MAX_ADDRESS
> - && __vm_allocate (__mach_task_self (), &base,
> - stacksize, FALSE) != KERN_SUCCESS; base += stacksize)
> - ;
> -
> - if (base >= VM_MAX_ADDRESS)
> - {
> - if (i == 1)
> - {
> - next_stack_base = VM_MIN_ADDRESS;
> - goto get_stack;
> - }
> - else
> - return EAGAIN;
> - }
> + error_t err;
>
> - next_stack_base = base + stacksize;
> + err = __vm_allocate (__mach_task_self (), (vm_offset_t *) stackaddr,
> + stacksize, TRUE);
>
> - (*stackaddr) = (void *) base;
> - return 0;
> + if (err == KERN_NO_SPACE)
> + err = EAGAIN;
> + return err;
> }
> --
> 2.41.0
>
>
--
Samuel
---
Pour une évaluation indépendante, transparente et rigoureuse !
Je soutiens la Commission d'Évaluation de l'Inria.
