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VMM - free_page unsets P2 entry if P1 is empty

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This commit is contained in:
Thomas Lovén 2017-12-29 23:33:48 +01:00
parent e62c167494
commit 3134a1d6ad
2 changed files with 29 additions and 0 deletions
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20
src/kernel/memory/vmm.c
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@ -82,4 +82,24 @@ void free_page(void *P4, uintptr_t addr, int free)
)) ))
return; return;
P1e(P4, addr).value = 0; P1e(P4, addr).value = 0;
union PTE *pt;
pt = PT(P2e(P4, addr).value);
for(int i = 0; i < ENTRIES_PER_PT; i++)
if(pt[i].value)
return;
P2e(P4, addr).value = 0;
pt = PT(P3e(P4, addr).value);
for(int i = 0; i < ENTRIES_PER_PT; i++)
if(pt[i].value)
return;
P3e(P4, addr).value = 0;
pt = PT(P4e(P4, addr).value);
for(int i = 0; i < ENTRIES_PER_PT; i++)
if(pt[i].value)
return;
P4e(P4, addr).value = 0;
} }

9
src/kernel/memory/vmm.tt
View File

@ -137,3 +137,12 @@ TEST(free_page_unsets_page)
ASSERT_EQ_PTR(p1[4], 0); ASSERT_EQ_PTR(p1[4], 0);
} }
TEST(free_page_unsets_P2_entry_if_P1_is_empty)
{
BUILD_PT(1,2,3);
p1[4] = PAGE_PRESENT;
free_page(p4, ADDR1234, 1);
ASSERT_EQ_PTR(p2[3], 0);
}