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aarch64: use __alloc_gcs in makecontext

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Szabolcs Nagy 2024-08-28 11:00:19 +01:00 committed by Yury Khrustalev
parent 9ecd8855cc
commit 27a873fa06
1 changed files with 6 additions and 35 deletions
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41
sysdeps/unix/sysv/linux/aarch64/makecontext.c
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@ -23,6 +23,7 @@
#include <stdlib.h>
#include <ucontext.h>
#include <sys/mman.h>
#include "aarch64-gcs.h"
#define GCS_MAGIC 0x47435300
@ -72,47 +73,17 @@ __libc_aarch64_thread_freeres (void)
free_gcs_list ();
}
#ifndef __NR_map_shadow_stack
# define __NR_map_shadow_stack 453
#endif
#ifndef SHADOW_STACK_SET_TOKEN
# define SHADOW_STACK_SET_TOKEN (1UL << 0)
# define SHADOW_STACK_SET_MARKER (1UL << 1)
#endif
static void *
map_shadow_stack (void *addr, size_t size, unsigned long flags)
{
return (void *) INLINE_SYSCALL_CALL (map_shadow_stack, addr, size, flags);
}
#define GCS_MAX_SIZE (1UL << 31)
#define GCS_ALTSTACK_RESERVE 160
static void *
alloc_makecontext_gcs (size_t stack_size)
{
size_t size = (stack_size / 2 + GCS_ALTSTACK_RESERVE) & -8UL;
if (size > GCS_MAX_SIZE)
size = GCS_MAX_SIZE;
unsigned long flags = SHADOW_STACK_SET_MARKER | SHADOW_STACK_SET_TOKEN;
void *base = map_shadow_stack (NULL, size, flags);
if (base == (void *) -1)
void *base;
size_t size;
void *gcsp = __alloc_gcs (stack_size, &base, &size);
if (gcsp == NULL)
/* ENOSYS, bad size or OOM. */
abort ();
record_gcs (base, size);
uint64_t *gcsp = (uint64_t *) ((char *) base + size);
/* Skip end of GCS token. */
gcsp--;
/* Verify GCS cap token. */
gcsp--;
if (((uint64_t)gcsp & 0xfffffffffffff000) + 1 != *gcsp)
abort ();
/* Return the target GCS pointer for context switch. */
return gcsp + 1;
return gcsp;
}
void