#include "test/jemalloc_test.h"
#include "test/arena_util.h"
#include "test/san.h"

#include "jemalloc/internal/san.h"

static void
verify_extent_guarded(tsdn_t *tsdn, void *ptr) {
       expect_true(extent_is_guarded(tsdn, ptr),
           "All extents should be guarded.");
}

#define MAX_SMALL_ALLOCATIONS 4096
void *small_alloc[MAX_SMALL_ALLOCATIONS];

/*
* This test allocates page sized slabs and checks that every two slabs have
* at least one page in between them. That page is supposed to be the guard
* page.
*/
TEST_BEGIN(test_guarded_small) {
       test_skip_if(opt_prof);

       tsdn_t *tsdn = tsd_tsdn(tsd_fetch());
       unsigned npages = 16, pages_found = 0, ends_found = 0;
       VARIABLE_ARRAY(uintptr_t, pages, npages);

       /* Allocate to get sanitized pointers. */
       size_t slab_sz = PAGE;
       size_t sz = slab_sz / 8;
       unsigned n_alloc = 0;
       while (n_alloc < MAX_SMALL_ALLOCATIONS) {
               void *ptr = malloc(sz);
               expect_ptr_not_null(ptr, "Unexpected malloc() failure");
               small_alloc[n_alloc] = ptr;
               verify_extent_guarded(tsdn, ptr);
               if ((uintptr_t)ptr % PAGE == 0) {
                       assert_u_lt(pages_found, npages,
                           "Unexpectedly large number of page aligned allocs");
                       pages[pages_found++] = (uintptr_t)ptr;
               }
               if (((uintptr_t)ptr + (uintptr_t)sz) % PAGE == 0) {
                       ends_found++;
               }
               n_alloc++;
               if (pages_found == npages && ends_found == npages) {
                       break;
               }
       }
       /* Should found the ptrs being checked for overflow and underflow. */
       expect_u_eq(pages_found, npages, "Could not found the expected pages.");
       expect_u_eq(ends_found, npages, "Could not found the expected pages.");

       /* Verify the pages are not continuous, i.e. separated by guards. */
       for (unsigned i = 0; i < npages - 1; i++) {
               for (unsigned j = i + 1; j < npages; j++) {
                       uintptr_t ptr_diff = pages[i] > pages[j] ?
                           pages[i] - pages[j] : pages[j] - pages[i];
                       expect_zu_ge((size_t)ptr_diff, slab_sz + PAGE,
                           "There should be at least one pages between "
                           "guarded slabs");
               }
       }

       for (unsigned i = 0; i < n_alloc + 1; i++) {
               free(small_alloc[i]);
       }
}
TEST_END

TEST_BEGIN(test_guarded_large) {
       tsdn_t *tsdn = tsd_tsdn(tsd_fetch());
       unsigned nlarge = 32;
       VARIABLE_ARRAY(uintptr_t, large, nlarge);

       /* Allocate to get sanitized pointers. */
       size_t large_sz = SC_LARGE_MINCLASS;
       for (unsigned i = 0; i < nlarge; i++) {
               void *ptr = malloc(large_sz);
               verify_extent_guarded(tsdn, ptr);
               expect_ptr_not_null(ptr, "Unexpected malloc() failure");
               large[i] = (uintptr_t)ptr;
       }

       /* Verify the pages are not continuous, i.e. separated by guards. */
       for (unsigned i = 0; i < nlarge; i++) {
               for (unsigned j = i + 1; j < nlarge; j++) {
                       uintptr_t ptr_diff = large[i] > large[j] ?
                           large[i] - large[j] : large[j] - large[i];
                       expect_zu_ge((size_t)ptr_diff, large_sz + 2 * PAGE,
                           "There should be at least two pages between "
                           " guarded large allocations");
               }
       }

       for (unsigned i = 0; i < nlarge; i++) {
               free((void *)large[i]);
       }
}
TEST_END

static void
verify_pdirty(unsigned arena_ind, uint64_t expected) {
       uint64_t pdirty = get_arena_pdirty(arena_ind);
       expect_u64_eq(pdirty, expected / PAGE,
           "Unexpected dirty page amount.");
}

static void
verify_pmuzzy(unsigned arena_ind, uint64_t expected) {
       uint64_t pmuzzy = get_arena_pmuzzy(arena_ind);
       expect_u64_eq(pmuzzy, expected / PAGE,
           "Unexpected muzzy page amount.");
}

TEST_BEGIN(test_guarded_decay) {
       unsigned arena_ind = do_arena_create(-1, -1);
       do_decay(arena_ind);
       do_purge(arena_ind);

       verify_pdirty(arena_ind, 0);
       verify_pmuzzy(arena_ind, 0);

       /* Verify that guarded extents as dirty. */
       size_t sz1 = PAGE, sz2 = PAGE * 2;
       /* W/o maps_coalesce, guarded extents are unguarded eagerly. */
       size_t add_guard_size = maps_coalesce ? 0 : SAN_PAGE_GUARDS_SIZE;
       generate_dirty(arena_ind, sz1);
       verify_pdirty(arena_ind, sz1 + add_guard_size);
       verify_pmuzzy(arena_ind, 0);

       /* Should reuse the first extent. */
       generate_dirty(arena_ind, sz1);
       verify_pdirty(arena_ind, sz1 + add_guard_size);
       verify_pmuzzy(arena_ind, 0);

       /* Should not reuse; expect new dirty pages. */
       generate_dirty(arena_ind, sz2);
       verify_pdirty(arena_ind, sz1 + sz2 + 2 * add_guard_size);
       verify_pmuzzy(arena_ind, 0);

       tsdn_t *tsdn = tsd_tsdn(tsd_fetch());
       int flags = MALLOCX_ARENA(arena_ind) | MALLOCX_TCACHE_NONE;

       /* Should reuse dirty extents for the two mallocx. */
       void *p1 = do_mallocx(sz1, flags);
       verify_extent_guarded(tsdn, p1);
       verify_pdirty(arena_ind, sz2 + add_guard_size);

       void *p2 = do_mallocx(sz2, flags);
       verify_extent_guarded(tsdn, p2);
       verify_pdirty(arena_ind, 0);
       verify_pmuzzy(arena_ind, 0);

       dallocx(p1, flags);
       verify_pdirty(arena_ind, sz1 + add_guard_size);
       dallocx(p2, flags);
       verify_pdirty(arena_ind, sz1 + sz2 + 2 * add_guard_size);
       verify_pmuzzy(arena_ind, 0);

       do_purge(arena_ind);
       verify_pdirty(arena_ind, 0);
       verify_pmuzzy(arena_ind, 0);

       if (config_stats) {
               expect_u64_eq(get_arena_npurge(arena_ind), 1,
                   "Expected purging to occur");
               expect_u64_eq(get_arena_dirty_npurge(arena_ind), 1,
                   "Expected purging to occur");
               expect_u64_eq(get_arena_dirty_purged(arena_ind),
                   (sz1 + sz2 + 2 * add_guard_size) / PAGE,
                   "Expected purging to occur");
               expect_u64_eq(get_arena_muzzy_npurge(arena_ind), 0,
                   "Expected purging to occur");
       }

       if (opt_retain) {
               /*
                * With retain, guarded extents are not mergable and will be
                * cached in ecache_retained.  They should be reused.
                */
               void *new_p1 = do_mallocx(sz1, flags);
               verify_extent_guarded(tsdn, p1);
               expect_ptr_eq(p1, new_p1, "Expect to reuse p1");

               void *new_p2 = do_mallocx(sz2, flags);
               verify_extent_guarded(tsdn, p2);
               expect_ptr_eq(p2, new_p2, "Expect to reuse p2");

               dallocx(new_p1, flags);
               verify_pdirty(arena_ind, sz1 + add_guard_size);
               dallocx(new_p2, flags);
               verify_pdirty(arena_ind, sz1 + sz2 + 2 * add_guard_size);
               verify_pmuzzy(arena_ind, 0);
       }

       do_arena_destroy(arena_ind);
}
TEST_END

int
main(void) {
       return test(
           test_guarded_small,
           test_guarded_large,
           test_guarded_decay);
}