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VMM - set_page does not overwrite 4kb pages with 2mb

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This commit is contained in:
Thomas Lovén 2018-01-02 12:24:02 +01:00
parent 518eaf73c3
commit e68698ff80
2 changed files with 10 additions and 0 deletions
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2
src/kernel/memory/vmm.c
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@ -56,6 +56,8 @@ int vmm_set_page(void *P4, uintptr_t addr, uintptr_t page, uint16_t flags)
&& P3e(P4, addr).present && P3e(P4, addr).present
)) ))
return -1; return -1;
if(P2e(P4, addr).present && !P2e(P4,addr).huge)
return -1;
P2e(P4, addr).value = page | flags; P2e(P4, addr).value = page | flags;
return 0; return 0;
} }

8
src/kernel/memory/vmm.tt
View File

@ -106,6 +106,14 @@ TEST(set_page_sets_2mb_pages)
ASSERT_EQ_PTR(p2[3], 0x1234567890A00000 | PAGE_HUGE | PAGE_PRESENT); ASSERT_EQ_PTR(p2[3], 0x1234567890A00000 | PAGE_HUGE | PAGE_PRESENT);
} }
TEST(set_page_does_not_overwrite_4kb_pages_with_2mb)
{
BUILD_PT(0,0,0);
int retval = vmm_set_page(p4, 0, 0, PAGE_HUGE | PAGE_PRESENT);
ASSERT_NEQ_INT(retval, 0);
}
uintptr_t pmm_alloc() uintptr_t pmm_alloc()
{ {