/*
 * 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, unsigned long 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,
                (unsigned long)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
}

void
protect_control_stack_guard_page(int protect_p) {
    struct thread *th = arch_os_get_current_thread();
    os_protect(CONTROL_STACK_GUARD_PAGE(th),
               os_vm_page_size,protect_p ?
               (OS_VM_PROT_READ|OS_VM_PROT_EXECUTE) : OS_VM_PROT_ALL);
}

void
protect_control_stack_return_guard_page(int protect_p) {
    struct thread *th = arch_os_get_current_thread();
    os_protect(CONTROL_STACK_RETURN_GUARD_PAGE(th),
               os_vm_page_size,protect_p ?
               (OS_VM_PROT_READ|OS_VM_PROT_EXECUTE) : OS_VM_PROT_ALL);
}

/* these OOAO violations are here because with mach exception handlers
 * we need to protect the stack guard pages from the mach exception
 * handlers which run on a different thread, so we take a thread
 * argument here. Too bad we don't have keywords args in C. */
void
protect_control_stack_guard_page_thread(int protect_p, struct thread *th) {
    os_protect(CONTROL_STACK_GUARD_PAGE(th),
               os_vm_page_size,protect_p ?
               (OS_VM_PROT_READ|OS_VM_PROT_EXECUTE) : OS_VM_PROT_ALL);
}

void
protect_control_stack_return_guard_page_thread(int protect_p, struct thread* th) {
    os_protect(CONTROL_STACK_RETURN_GUARD_PAGE(th),
               os_vm_page_size,protect_p ?
               (OS_VM_PROT_READ|OS_VM_PROT_EXECUTE) : OS_VM_PROT_ALL);
}