x86/mm: Split read_cr3() into read_cr3_pa() and __read_cr3()
The kernel has several code paths that read CR3. Most of them assume that
CR3 contains the PGD's physical address, whereas some of them awkwardly
use PHYSICAL_PAGE_MASK to mask off low bits.
Add explicit mask macros for CR3 and convert all of the CR3 readers.
This will keep them from breaking when PCID is enabled.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: xen-devel <xen-devel@lists.xen.org>
Link: http://lkml.kernel.org/r/883f8fb121f4616c1c1427ad87350bb2f5ffeca1.1497288170.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 8ad91a0..2a1fa10c 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -346,7 +346,7 @@ static noinline int vmalloc_fault(unsigned long address)
* Do _not_ use "current" here. We might be inside
* an interrupt in the middle of a task switch..
*/
- pgd_paddr = read_cr3();
+ pgd_paddr = read_cr3_pa();
pmd_k = vmalloc_sync_one(__va(pgd_paddr), address);
if (!pmd_k)
return -1;
@@ -388,7 +388,7 @@ static bool low_pfn(unsigned long pfn)
static void dump_pagetable(unsigned long address)
{
- pgd_t *base = __va(read_cr3());
+ pgd_t *base = __va(read_cr3_pa());
pgd_t *pgd = &base[pgd_index(address)];
p4d_t *p4d;
pud_t *pud;
@@ -451,7 +451,7 @@ static noinline int vmalloc_fault(unsigned long address)
* happen within a race in page table update. In the later
* case just flush:
*/
- pgd = (pgd_t *)__va(read_cr3()) + pgd_index(address);
+ pgd = (pgd_t *)__va(read_cr3_pa()) + pgd_index(address);
pgd_ref = pgd_offset_k(address);
if (pgd_none(*pgd_ref))
return -1;
@@ -555,7 +555,7 @@ static int bad_address(void *p)
static void dump_pagetable(unsigned long address)
{
- pgd_t *base = __va(read_cr3() & PHYSICAL_PAGE_MASK);
+ pgd_t *base = __va(read_cr3_pa());
pgd_t *pgd = base + pgd_index(address);
p4d_t *p4d;
pud_t *pud;
@@ -700,7 +700,7 @@ show_fault_oops(struct pt_regs *regs, unsigned long error_code,
pgd_t *pgd;
pte_t *pte;
- pgd = __va(read_cr3() & PHYSICAL_PAGE_MASK);
+ pgd = __va(read_cr3_pa());
pgd += pgd_index(address);
pte = lookup_address_in_pgd(pgd, address, &level);