[PATCH v6 10/34] x86, x86/mm, x86/xen, olpc: Use __va() against just the physical address in cr3

From: Tom Lendacky
Date: Wed Jun 07 2017 - 15:15:21 EST


The cr3 register entry can contain the SME encryption bit that indicates
the PGD is encrypted. The encryption bit should not be used when creating
a virtual address for the PGD table.

Create a new function, read_cr3_pa(), that will extract the physical
address from the cr3 register. This function is then used where a virtual
address of the PGD needs to be created/used from the cr3 register.

Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
---
arch/x86/include/asm/special_insns.h | 9 +++++++++
arch/x86/kernel/head64.c | 2 +-
arch/x86/mm/fault.c | 10 +++++-----
arch/x86/mm/ioremap.c | 2 +-
arch/x86/platform/olpc/olpc-xo1-pm.c | 2 +-
arch/x86/power/hibernate_64.c | 2 +-
arch/x86/xen/mmu_pv.c | 6 +++---
7 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h
index 12af3e3..d8e8ace 100644
--- a/arch/x86/include/asm/special_insns.h
+++ b/arch/x86/include/asm/special_insns.h
@@ -234,6 +234,15 @@ static inline void clwb(volatile void *__p)

#define nop() asm volatile ("nop")

+static inline unsigned long native_read_cr3_pa(void)
+{
+ return (native_read_cr3() & PHYSICAL_PAGE_MASK);
+}
+
+static inline unsigned long read_cr3_pa(void)
+{
+ return (read_cr3() & PHYSICAL_PAGE_MASK);
+}

#endif /* __KERNEL__ */

diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 43b7002..dc03624 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -55,7 +55,7 @@ int __init early_make_pgtable(unsigned long address)
pmdval_t pmd, *pmd_p;

/* Invalid address or early pgt is done ? */
- if (physaddr >= MAXMEM || read_cr3() != __pa_nodebug(early_level4_pgt))
+ if (physaddr >= MAXMEM || read_cr3_pa() != __pa_nodebug(early_level4_pgt))
return -1;

again:
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 @@ static int is_f00f_bug(struct pt_regs *regs, unsigned long address)
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);
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 2a0fa89..e6305dd 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -427,7 +427,7 @@ void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr)
static inline pmd_t * __init early_ioremap_pmd(unsigned long addr)
{
/* Don't assume we're using swapper_pg_dir at this point */
- pgd_t *base = __va(read_cr3());
+ pgd_t *base = __va(read_cr3_pa());
pgd_t *pgd = &base[pgd_index(addr)];
p4d_t *p4d = p4d_offset(pgd, addr);
pud_t *pud = pud_offset(p4d, addr);
diff --git a/arch/x86/platform/olpc/olpc-xo1-pm.c b/arch/x86/platform/olpc/olpc-xo1-pm.c
index c5350fd..0668aaf 100644
--- a/arch/x86/platform/olpc/olpc-xo1-pm.c
+++ b/arch/x86/platform/olpc/olpc-xo1-pm.c
@@ -77,7 +77,7 @@ static int xo1_power_state_enter(suspend_state_t pm_state)

asmlinkage __visible int xo1_do_sleep(u8 sleep_state)
{
- void *pgd_addr = __va(read_cr3());
+ void *pgd_addr = __va(read_cr3_pa());

/* Program wakeup mask (using dword access to CS5536_PM1_EN) */
outl(wakeup_mask << 16, acpi_base + CS5536_PM1_STS);
diff --git a/arch/x86/power/hibernate_64.c b/arch/x86/power/hibernate_64.c
index a6e21fe..0a7650d 100644
--- a/arch/x86/power/hibernate_64.c
+++ b/arch/x86/power/hibernate_64.c
@@ -150,7 +150,7 @@ static int relocate_restore_code(void)
memcpy((void *)relocated_restore_code, &core_restore_code, PAGE_SIZE);

/* Make the page containing the relocated code executable */
- pgd = (pgd_t *)__va(read_cr3()) + pgd_index(relocated_restore_code);
+ pgd = (pgd_t *)__va(read_cr3_pa()) + pgd_index(relocated_restore_code);
p4d = p4d_offset(pgd, relocated_restore_code);
if (p4d_large(*p4d)) {
set_p4d(p4d, __p4d(p4d_val(*p4d) & ~_PAGE_NX));
diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c
index 1f386d7..2dc5243 100644
--- a/arch/x86/xen/mmu_pv.c
+++ b/arch/x86/xen/mmu_pv.c
@@ -2022,7 +2022,7 @@ static phys_addr_t __init xen_early_virt_to_phys(unsigned long vaddr)
pmd_t pmd;
pte_t pte;

- pa = read_cr3();
+ pa = read_cr3_pa();
pgd = native_make_pgd(xen_read_phys_ulong(pa + pgd_index(vaddr) *
sizeof(pgd)));
if (!pgd_present(pgd))
@@ -2102,7 +2102,7 @@ void __init xen_relocate_p2m(void)
pt_phys = pmd_phys + PFN_PHYS(n_pmd);
p2m_pfn = PFN_DOWN(pt_phys) + n_pt;

- pgd = __va(read_cr3());
+ pgd = __va(read_cr3_pa());
new_p2m = (unsigned long *)(2 * PGDIR_SIZE);
idx_p4d = 0;
save_pud = n_pud;
@@ -2209,7 +2209,7 @@ static void __init xen_write_cr3_init(unsigned long cr3)
{
unsigned long pfn = PFN_DOWN(__pa(swapper_pg_dir));

- BUG_ON(read_cr3() != __pa(initial_page_table));
+ BUG_ON(read_cr3_pa() != __pa(initial_page_table));
BUG_ON(cr3 != __pa(swapper_pg_dir));

/*