/*
 * memory validation
 */

/*
 * This software is part of the SBCL system. See the README file for
 * more information.
 *
 * This software is derived from the CMU CL system, which was
 * written at Carnegie Mellon University and released into the
 * public domain. The software is in the public domain and is
 * provided with absolutely no warranty. See the COPYING and CREDITS
 * files for more information.
 */

#include <stdio.h>
#include <stdlib.h>

#include "sbcl.h"
#include "runtime.h"
#include "os.h"
#include "globals.h"
#include "interr.h"
#include "validate.h"
#include "interr.h"                     /* for declaration of lose */


static void
ensure_space(lispobj *start, uword_t size)
{
    if (os_validate((os_vm_address_t)start,(os_vm_size_t)size)==NULL) {
        fprintf(stderr,
                "ensure_space: failed to validate %ld bytes at 0x%08lx\n",
                size,
                (uword_t)start);
        fprintf(stderr,
                "(hint: Try \"ulimit -a\"; maybe you should increase memory limits.)\n");
        exit(1);
    }
}

os_vm_address_t undefined_alien_address = 0;

static void
ensure_undefined_alien(void) {
    os_vm_address_t start = os_validate(NULL, os_vm_page_size);
    if (start) {
        os_protect(start, os_vm_page_size, OS_VM_PROT_NONE);
        undefined_alien_address = start;
    } else {
        lose("could not allocate guard page for undefined alien\n");
    }
}

void
validate(void)
{
#ifdef PRINTNOISE
    printf("validating memory ...");
    fflush(stdout);
#endif

    ensure_space( (lispobj *)READ_ONLY_SPACE_START, READ_ONLY_SPACE_SIZE);
    ensure_space( (lispobj *)STATIC_SPACE_START   , STATIC_SPACE_SIZE);
#ifdef LISP_FEATURE_GENCGC
    ensure_space( (lispobj *)DYNAMIC_SPACE_START  , dynamic_space_size);
#else
    ensure_space( (lispobj *)DYNAMIC_0_SPACE_START, dynamic_space_size);
    ensure_space( (lispobj *)DYNAMIC_1_SPACE_START, dynamic_space_size);
#endif

#ifdef LISP_FEATURE_LINKAGE_TABLE
    ensure_space( (lispobj *)LINKAGE_TABLE_SPACE_START,
                  LINKAGE_TABLE_SPACE_SIZE);
#endif

#ifdef LISP_FEATURE_OS_PROVIDES_DLOPEN
    ensure_undefined_alien();
#endif

#ifdef PRINTNOISE
    printf(" done.\n");
#endif
}

static inline void
protect_page(void *page, int protect_p, os_vm_prot_t flags) {
    os_protect(page, os_vm_page_size, protect_p ?
               flags : OS_VM_PROT_ALL);
}

#define DEF_PROTECT_PAGE(name,page_name,flags)                          \
    void                                                                \
    protect_##name(int protect_p, struct thread *thread) {              \
        if (!thread)                                                    \
            thread = arch_os_get_current_thread();                      \
        protect_page(page_name(thread), protect_p, flags);              \
    }

DEF_PROTECT_PAGE(control_stack_hard_guard_page,
                 CONTROL_STACK_HARD_GUARD_PAGE,
                 OS_VM_PROT_NONE)
DEF_PROTECT_PAGE(control_stack_guard_page,
                 CONTROL_STACK_GUARD_PAGE,
                 OS_VM_PROT_READ|OS_VM_PROT_EXECUTE)
DEF_PROTECT_PAGE(control_stack_return_guard_page,
                 CONTROL_STACK_RETURN_GUARD_PAGE,
                 OS_VM_PROT_READ|OS_VM_PROT_EXECUTE)

DEF_PROTECT_PAGE(binding_stack_hard_guard_page,
                 BINDING_STACK_HARD_GUARD_PAGE,
                 OS_VM_PROT_NONE)
DEF_PROTECT_PAGE(binding_stack_guard_page,
                 BINDING_STACK_GUARD_PAGE,
                 OS_VM_PROT_NONE)
DEF_PROTECT_PAGE(binding_stack_return_guard_page,
                 BINDING_STACK_RETURN_GUARD_PAGE,
                 OS_VM_PROT_NONE)

DEF_PROTECT_PAGE(alien_stack_hard_guard_page,
                 ALIEN_STACK_HARD_GUARD_PAGE,
                 OS_VM_PROT_NONE)
DEF_PROTECT_PAGE(alien_stack_guard_page,
                 ALIEN_STACK_GUARD_PAGE,
                 OS_VM_PROT_NONE)
DEF_PROTECT_PAGE(alien_stack_return_guard_page,
                 ALIEN_STACK_RETURN_GUARD_PAGE,
                 OS_VM_PROT_NONE)
