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VMM - get_page ignores flags -- also restructuring - bad Thomas!

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This commit is contained in:
Thomas Lovén 2017-12-23 22:01:07 +01:00
parent 1b928b3c97
commit 1ad156902a
2 changed files with 34 additions and 15 deletions
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33
src/kernel/memory/vmm.c
View File

@ -1,26 +1,31 @@
#include <memory.h> #include <memory.h>
#define FLAGS_MASK (PAGE_SIZE-1) #define FLAGS_MASK (PAGE_SIZE-1)
#define MASK_FLAGS(addr) ((uintptr_t)addr & ~FLAGS_MASK)
struct PT { union PTE {
struct PT *p[ENTRIES_PER_PT]; uint64_t value;
}__attribute__((packed)); struct {
uintptr_t flags:12;
};
};
#define P(pt) ((struct PT *)((uintptr_t)pt & ~(FLAGS_MASK))) typedef union PTE PT[512];
#define P3(pt, addr) (P(pt)->p[P4_OFFSET(addr)]) #define PT(ptr) ((PT *)MASK_FLAGS(ptr->value))
#define P2(pt, addr) (P(P3(pt, addr))->p[P3_OFFSET(addr)]) #define P4e(pt, addr) (((PT *)pt)[P4_OFFSET(addr)])
#define P1(pt, addr) (P(P2(pt, addr))->p[P2_OFFSET(addr)]) #define P3e(pt, addr) PT(P4e(pt, addr))[P3_OFFSET(addr)]
#define P0(pt, addr) (P(P1(pt, addr))->p[P1_OFFSET(addr)]) #define P2e(pt, addr) PT(P3e(pt, addr))[P2_OFFSET(addr)]
#define P1e(pt, addr) PT(P2e(pt, addr))[P1_OFFSET(addr)]
uintptr_t vmm_get_page(void *P4, uintptr_t addr)
uintptr_t vmm_get_page(uintptr_t *P4, uintptr_t addr)
{ {
if(P4 if(P4
&& P3(P4, addr) && P4e(P4, addr)
&& P2(P4, addr) && P3e(P4, addr)
&& P1(P4, addr) && P2e(P4, addr)
) )
return (uintptr_t)P0(P4, addr); return MASK_FLAGS(P1e(P4, addr)->value);
else
return 0; return 0;
} }

14
src/kernel/memory/vmm.tt
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@ -30,3 +30,17 @@ TEST(get_page_returns_correct_address)
ASSERT_EQ_PTR(ret, 0x1234567890ABC000); ASSERT_EQ_PTR(ret, 0x1234567890ABC000);
} }
TEST(get_page_ignores_flags)
{
p4[0] = (uintptr_t)p3;
p4[0] |= 0x123;
p3[0] = (uintptr_t)p2;
p3[0] |= 0x456;
p2[0] = (uintptr_t)p1;
p2[0] |= 0x789;
p1[0] = 0x1234567890ABCDEF;
uintptr_t ret = vmm_get_page(p4, 0);
ASSERT_EQ_PTR(ret, 0x1234567890ABC000);
}