/*

* Shared mapping creation.

*/

#include <malloc.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#include <sys/mman.h>

#include "arch.h"

#include "child.h"

#include "log.h"

#include "params.h"

#include "pids.h"

#include "random.h"

#include "shm.h"

#include "utils.h"

struct shm_s *shm;

#define SHM_PROT_PAGES 30

unsigned int shm_size;

void create_shm(void)

{

unsigned int nr_shm_pages;

/* round up shm to nearest page size */

shm_size = (sizeof(struct shm_s) + page_size - 1) & PAGE_MASK;

nr_shm_pages = shm_size / page_size;

/* Waste some address space to set up some "protection" near the SHM location. */

shm = alloc_shared(shm_size);

/* clear the whole shm. */

memset(shm, 0, shm_size);

printf("shm:%p-%p (%u pages)\n", shm, shm + shm_size - 1, nr_shm_pages);

}

void shm_ro(void)

{

if (shm->debug == TRUE)

mprotect(shm, shm_size, PROT_READ);

}

void shm_rw(void)

{

if (shm->debug == TRUE)

mprotect(shm, shm_size, PROT_READ|PROT_WRITE);

}

void init_shm(void)

{

unsigned int i;

unsigned int childptrslen;

output(2, "shm is at %p\n", shm);

if (set_debug == TRUE)

shm->debug = TRUE;

shm->stats.total_syscalls_done = 1;

if (user_set_seed == TRUE)

shm->seed = init_seed(seed);

else

shm->seed = new_seed();

/* Set seed in parent thread */

set_seed(NULL);

childptrslen = max_children * sizeof(struct childdata *);

/* round up to page size */

childptrslen += page_size - 1;

childptrslen &= PAGE_MASK;

shm->children = memalign(page_size, childptrslen);

if (shm->children == NULL) {

printf("Failed to allocate child structures.\n");

exit(EXIT_FAILURE);

}

memset(shm->children, 0, childptrslen);

/* We allocate the childdata structs as shared mappings, because

* the watchdog process needs to peek into each childs syscall records

* to make sure they are making progress.

*/

for_each_child(i) {

struct childdata *child;

child = alloc_shared(sizeof(struct childdata));

shm->children[i] = child;

memset(&child->syscall, 0, sizeof(struct syscallrecord));

child->pid = EMPTY_PIDSLOT;

child->num = i;

init_child_logging(child);

}

mprotect(shm->children, childptrslen, PROT_READ);

}