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PMM -- calloc function for getting cleared pages

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This commit is contained in:
Thomas Lovén 2018-01-04 00:36:59 +01:00
parent 5dc4e27392
commit 3a4136c225
4 changed files with 13 additions and 5 deletions
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1
src/kernel/include/memory.h
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@ -33,6 +33,7 @@ size_t strlen(const char *s);
void pmm_free(uintptr_t page); void pmm_free(uintptr_t page);
uintptr_t pmm_alloc(); uintptr_t pmm_alloc();
uintptr_t pmm_calloc();
uintptr_t vmm_get_page(void *P4, uintptr_t addr); uintptr_t vmm_get_page(void *P4, uintptr_t addr);
int vmm_set_page(void *P4, uintptr_t addr, uintptr_t page, uint16_t flags); int vmm_set_page(void *P4, uintptr_t addr, uintptr_t page, uint16_t flags);

7
src/kernel/memory/pmm.c
View File

@ -16,3 +16,10 @@ uintptr_t pmm_alloc()
page = (uintptr_t)(page?V2P(page):0); page = (uintptr_t)(page?V2P(page):0);
return page; return page;
} }
uintptr_t pmm_calloc()
{
uintptr_t page = pmm_alloc();
memset(P2V(page), 0, 0x1000);
return page;
}

6
src/kernel/memory/vmm.c
View File

@ -77,19 +77,19 @@ int touch_page(void *P4, uintptr_t addr, uint16_t flags)
flags ^= PAGE_HUGE*huge; flags ^= PAGE_HUGE*huge;
if((!P4e(P4, addr).present) if((!P4e(P4, addr).present)
&& (!(P4e(P4, addr).value = pmm_alloc()))) && (!(P4e(P4, addr).value = pmm_calloc())))
return -1; return -1;
P4e(P4, addr).value |= flags | PAGE_PRESENT; P4e(P4, addr).value |= flags | PAGE_PRESENT;
if((!P3e(P4, addr).present) if((!P3e(P4, addr).present)
&& (!(P3e(P4, addr).value = pmm_alloc()))) && (!(P3e(P4, addr).value = pmm_calloc())))
return -1; return -1;
P3e(P4, addr).value |= flags | PAGE_PRESENT; P3e(P4, addr).value |= flags | PAGE_PRESENT;
if(huge) return 0; if(huge) return 0;
if((!P2e(P4, addr).present) if((!P2e(P4, addr).present)
&& (!(P2e(P4, addr).value = pmm_alloc()))) && (!(P2e(P4, addr).value = pmm_calloc())))
return -1; return -1;
P2e(P4, addr).value |= flags | PAGE_PRESENT; P2e(P4, addr).value |= flags | PAGE_PRESENT;

4
src/kernel/memory/vmm.tt
View File

@ -119,7 +119,7 @@ TEST(set_page_does_not_overwrite_4kb_pages_with_2mb)
ASSERT_NEQ_INT(retval, 0); ASSERT_NEQ_INT(retval, 0);
} }
uintptr_t pmm_alloc() uintptr_t pmm_calloc()
{ {
uintptr_t *pages[] = {p3, p2, p1}; uintptr_t *pages[] = {p3, p2, p1};
static int counter=0; static int counter=0;
@ -153,7 +153,7 @@ TEST(touch_page_sets_flags)
} }
TEST(touch_page_fails_if_out_of_pages) TEST(touch_page_fails_if_out_of_pages)
{ {
pmm_alloc(); pmm_calloc();
int retval = touch_page(p4, 0, 0); int retval = touch_page(p4, 0, 0);
ASSERT_NEQ_INT(retval, 0); ASSERT_NEQ_INT(retval, 0);
} }