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In general, bits in the page directory entry (PDE) and the page table

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entry (PTE) have the same meaning.  The exception to this rule is the
eighth bit (0x080).  It is the PS bit in a PDE and the PAT bit in a
PTE.  This change avoids the possibility that pmap_enter() confuses a
PAT bit with a PS bit, avoiding a panic().

Eliminate a diagnostic printf() from the i386 pmap_enter() that serves
no current purpose, i.e., I've seen no bug reports in the last two
years that are helped by this printf().

Reviewed by: jhb
This commit is contained in:
Alan Cox 2006-04-27 21:26:25 +00:00
parent bd02c63f13
commit 7dece6c7d9
2 changed files with 12 additions and 14 deletions
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12
sys/amd64/amd64/pmap.c
View File

@ -2061,6 +2061,7 @@ pmap_enter(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot,
boolean_t wired)
{
vm_paddr_t pa;
pd_entry_t *pde;
register pt_entry_t *pte;
vm_paddr_t opa;
pt_entry_t origpte, newpte;
@ -2098,7 +2099,13 @@ pmap_enter(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot,
}
#endif
pte = pmap_pte(pmap, va);
pde = pmap_pde(pmap, va);
if (pde != NULL) {
if ((*pde & PG_PS) != 0)
panic("pmap_enter: attempted pmap_enter on 2MB page");
pte = pmap_pde_to_pte(pde, va);
} else
pte = NULL;
/*
* Page Directory table entry not valid, we need a new PT page
@ -2111,9 +2118,6 @@ pmap_enter(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot,
origpte = *pte;
opa = origpte & PG_FRAME;
if (origpte & PG_PS)
panic("pmap_enter: attempted pmap_enter on 2MB page");
/*
* Mapping has not changed, must be protection or wiring change.
*/

14
sys/i386/i386/pmap.c
View File

@ -2090,6 +2090,7 @@ pmap_enter(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot,
boolean_t wired)
{
vm_paddr_t pa;
pd_entry_t *pde;
register pt_entry_t *pte;
vm_paddr_t opa;
pt_entry_t origpte, newpte;
@ -2128,6 +2129,9 @@ pmap_enter(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot,
}
#endif
pde = pmap_pde(pmap, va);
if ((*pde & PG_PS) != 0)
panic("pmap_enter: attempted pmap_enter on 4MB page");
pte = pmap_pte_quick(pmap, va);
/*
@ -2143,16 +2147,6 @@ pmap_enter(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot,
origpte = *pte;
opa = origpte & PG_FRAME;
if (origpte & PG_PS) {
/*
* Yes, I know this will truncate upper address bits for PAE,
* but I'm actually more interested in the lower bits
*/
printf("pmap_enter: va %p, pte %p, origpte %p\n",
(void *)va, (void *)pte, (void *)(uintptr_t)origpte);
panic("pmap_enter: attempted pmap_enter on 4MB page");
}
/*
* Mapping has not changed, must be protection or wiring change.
*/