* [PATCH 4.14 21/22] ioremap: Update pgtable free interfaces with addr
[not found] <20180816171622.831964729@linuxfoundation.org>
2018-08-16 18:45 ` [PATCH 4.14 03/22] x86/mm: Disable ioremap free page handling on x86-PAE Greg Kroah-Hartman
@ 2018-08-16 18:45 ` Greg Kroah-Hartman
2018-08-16 18:45 ` [PATCH 4.14 22/22] x86/mm: Add TLB purge to free pmd/pte page interfaces Greg Kroah-Hartman
2 siblings, 0 replies; 3+ messages in thread
From: Greg Kroah-Hartman @ 2018-08-16 18:45 UTC (permalink / raw)
To: linux-arm-kernel
4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Chintan Pandya <cpandya@codeaurora.org>
commit 785a19f9d1dd8a4ab2d0633be4656653bd3de1fc upstream.
The following kernel panic was observed on ARM64 platform due to a stale
TLB entry.
1. ioremap with 4K size, a valid pte page table is set.
2. iounmap it, its pte entry is set to 0.
3. ioremap the same address with 2M size, update its pmd entry with
a new value.
4. CPU may hit an exception because the old pmd entry is still in TLB,
which leads to a kernel panic.
Commit b6bdb7517c3d ("mm/vmalloc: add interfaces to free unmapped page
table") has addressed this panic by falling to pte mappings in the above
case on ARM64.
To support pmd mappings in all cases, TLB purge needs to be performed
in this case on ARM64.
Add a new arg, 'addr', to pud_free_pmd_page() and pmd_free_pte_page()
so that TLB purge can be added later in seprate patches.
[toshi.kani at hpe.com: merge changes, rewrite patch description]
Fixes: 28ee90fe6048 ("x86/mm: implement free pmd/pte page interfaces")
Signed-off-by: Chintan Pandya <cpandya@codeaurora.org>
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: mhocko at suse.com
Cc: akpm at linux-foundation.org
Cc: hpa at zytor.com
Cc: linux-mm at kvack.org
Cc: linux-arm-kernel at lists.infradead.org
Cc: Will Deacon <will.deacon@arm.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: stable at vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20180627141348.21777-3-toshi.kani at hpe.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/arm64/mm/mmu.c | 4 ++--
arch/x86/mm/pgtable.c | 12 +++++++-----
include/asm-generic/pgtable.h | 8 ++++----
lib/ioremap.c | 4 ++--
4 files changed, 15 insertions(+), 13 deletions(-)
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -938,12 +938,12 @@ int pmd_clear_huge(pmd_t *pmd)
return 1;
}
-int pud_free_pmd_page(pud_t *pud)
+int pud_free_pmd_page(pud_t *pud, unsigned long addr)
{
return pud_none(*pud);
}
-int pmd_free_pte_page(pmd_t *pmd)
+int pmd_free_pte_page(pmd_t *pmd, unsigned long addr)
{
return pmd_none(*pmd);
}
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -716,11 +716,12 @@ int pmd_clear_huge(pmd_t *pmd)
/**
* pud_free_pmd_page - Clear pud entry and free pmd page.
* @pud: Pointer to a PUD.
+ * @addr: Virtual address associated with pud.
*
* Context: The pud range has been unmaped and TLB purged.
* Return: 1 if clearing the entry succeeded. 0 otherwise.
*/
-int pud_free_pmd_page(pud_t *pud)
+int pud_free_pmd_page(pud_t *pud, unsigned long addr)
{
pmd_t *pmd;
int i;
@@ -731,7 +732,7 @@ int pud_free_pmd_page(pud_t *pud)
pmd = (pmd_t *)pud_page_vaddr(*pud);
for (i = 0; i < PTRS_PER_PMD; i++)
- if (!pmd_free_pte_page(&pmd[i]))
+ if (!pmd_free_pte_page(&pmd[i], addr + (i * PMD_SIZE)))
return 0;
pud_clear(pud);
@@ -743,11 +744,12 @@ int pud_free_pmd_page(pud_t *pud)
/**
* pmd_free_pte_page - Clear pmd entry and free pte page.
* @pmd: Pointer to a PMD.
+ * @addr: Virtual address associated with pmd.
*
* Context: The pmd range has been unmaped and TLB purged.
* Return: 1 if clearing the entry succeeded. 0 otherwise.
*/
-int pmd_free_pte_page(pmd_t *pmd)
+int pmd_free_pte_page(pmd_t *pmd, unsigned long addr)
{
pte_t *pte;
@@ -763,7 +765,7 @@ int pmd_free_pte_page(pmd_t *pmd)
#else /* !CONFIG_X86_64 */
-int pud_free_pmd_page(pud_t *pud)
+int pud_free_pmd_page(pud_t *pud, unsigned long addr)
{
return pud_none(*pud);
}
@@ -772,7 +774,7 @@ int pud_free_pmd_page(pud_t *pud)
* Disable free page handling on x86-PAE. This assures that ioremap()
* does not update sync'd pmd entries. See vmalloc_sync_one().
*/
-int pmd_free_pte_page(pmd_t *pmd)
+int pmd_free_pte_page(pmd_t *pmd, unsigned long addr)
{
return pmd_none(*pmd);
}
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -991,8 +991,8 @@ int pud_set_huge(pud_t *pud, phys_addr_t
int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot);
int pud_clear_huge(pud_t *pud);
int pmd_clear_huge(pmd_t *pmd);
-int pud_free_pmd_page(pud_t *pud);
-int pmd_free_pte_page(pmd_t *pmd);
+int pud_free_pmd_page(pud_t *pud, unsigned long addr);
+int pmd_free_pte_page(pmd_t *pmd, unsigned long addr);
#else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
static inline int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot)
{
@@ -1018,11 +1018,11 @@ static inline int pmd_clear_huge(pmd_t *
{
return 0;
}
-static inline int pud_free_pmd_page(pud_t *pud)
+static inline int pud_free_pmd_page(pud_t *pud, unsigned long addr)
{
return 0;
}
-static inline int pmd_free_pte_page(pmd_t *pmd)
+static inline int pmd_free_pte_page(pmd_t *pmd, unsigned long addr)
{
return 0;
}
--- a/lib/ioremap.c
+++ b/lib/ioremap.c
@@ -92,7 +92,7 @@ static inline int ioremap_pmd_range(pud_
if (ioremap_pmd_enabled() &&
((next - addr) == PMD_SIZE) &&
IS_ALIGNED(phys_addr + addr, PMD_SIZE) &&
- pmd_free_pte_page(pmd)) {
+ pmd_free_pte_page(pmd, addr)) {
if (pmd_set_huge(pmd, phys_addr + addr, prot))
continue;
}
@@ -119,7 +119,7 @@ static inline int ioremap_pud_range(p4d_
if (ioremap_pud_enabled() &&
((next - addr) == PUD_SIZE) &&
IS_ALIGNED(phys_addr + addr, PUD_SIZE) &&
- pud_free_pmd_page(pud)) {
+ pud_free_pmd_page(pud, addr)) {
if (pud_set_huge(pud, phys_addr + addr, prot))
continue;
}
^ permalink raw reply [flat|nested] 3+ messages in thread* [PATCH 4.14 22/22] x86/mm: Add TLB purge to free pmd/pte page interfaces
[not found] <20180816171622.831964729@linuxfoundation.org>
2018-08-16 18:45 ` [PATCH 4.14 03/22] x86/mm: Disable ioremap free page handling on x86-PAE Greg Kroah-Hartman
2018-08-16 18:45 ` [PATCH 4.14 21/22] ioremap: Update pgtable free interfaces with addr Greg Kroah-Hartman
@ 2018-08-16 18:45 ` Greg Kroah-Hartman
2 siblings, 0 replies; 3+ messages in thread
From: Greg Kroah-Hartman @ 2018-08-16 18:45 UTC (permalink / raw)
To: linux-arm-kernel
4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Toshi Kani <toshi.kani@hpe.com>
commit 5e0fb5df2ee871b841f96f9cb6a7f2784e96aa4e upstream.
ioremap() calls pud_free_pmd_page() / pmd_free_pte_page() when it creates
a pud / pmd map. The following preconditions are met at their entry.
- All pte entries for a target pud/pmd address range have been cleared.
- System-wide TLB purges have been peformed for a target pud/pmd address
range.
The preconditions assure that there is no stale TLB entry for the range.
Speculation may not cache TLB entries since it requires all levels of page
entries, including ptes, to have P & A-bits set for an associated address.
However, speculation may cache pud/pmd entries (paging-structure caches)
when they have P-bit set.
Add a system-wide TLB purge (INVLPG) to a single page after clearing
pud/pmd entry's P-bit.
SDM 4.10.4.1, Operation that Invalidate TLBs and Paging-Structure Caches,
states that:
INVLPG invalidates all paging-structure caches associated with the
current PCID regardless of the liner addresses to which they correspond.
Fixes: 28ee90fe6048 ("x86/mm: implement free pmd/pte page interfaces")
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: mhocko at suse.com
Cc: akpm at linux-foundation.org
Cc: hpa at zytor.com
Cc: cpandya at codeaurora.org
Cc: linux-mm at kvack.org
Cc: linux-arm-kernel at lists.infradead.org
Cc: Joerg Roedel <joro@8bytes.org>
Cc: stable at vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20180627141348.21777-4-toshi.kani at hpe.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/mm/pgtable.c | 38 +++++++++++++++++++++++++++++++-------
1 file changed, 31 insertions(+), 7 deletions(-)
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -718,24 +718,44 @@ int pmd_clear_huge(pmd_t *pmd)
* @pud: Pointer to a PUD.
* @addr: Virtual address associated with pud.
*
- * Context: The pud range has been unmaped and TLB purged.
+ * Context: The pud range has been unmapped and TLB purged.
* Return: 1 if clearing the entry succeeded. 0 otherwise.
+ *
+ * NOTE: Callers must allow a single page allocation.
*/
int pud_free_pmd_page(pud_t *pud, unsigned long addr)
{
- pmd_t *pmd;
+ pmd_t *pmd, *pmd_sv;
+ pte_t *pte;
int i;
if (pud_none(*pud))
return 1;
pmd = (pmd_t *)pud_page_vaddr(*pud);
-
- for (i = 0; i < PTRS_PER_PMD; i++)
- if (!pmd_free_pte_page(&pmd[i], addr + (i * PMD_SIZE)))
- return 0;
+ pmd_sv = (pmd_t *)__get_free_page(GFP_KERNEL);
+ if (!pmd_sv)
+ return 0;
+
+ for (i = 0; i < PTRS_PER_PMD; i++) {
+ pmd_sv[i] = pmd[i];
+ if (!pmd_none(pmd[i]))
+ pmd_clear(&pmd[i]);
+ }
pud_clear(pud);
+
+ /* INVLPG to clear all paging-structure caches */
+ flush_tlb_kernel_range(addr, addr + PAGE_SIZE-1);
+
+ for (i = 0; i < PTRS_PER_PMD; i++) {
+ if (!pmd_none(pmd_sv[i])) {
+ pte = (pte_t *)pmd_page_vaddr(pmd_sv[i]);
+ free_page((unsigned long)pte);
+ }
+ }
+
+ free_page((unsigned long)pmd_sv);
free_page((unsigned long)pmd);
return 1;
@@ -746,7 +766,7 @@ int pud_free_pmd_page(pud_t *pud, unsign
* @pmd: Pointer to a PMD.
* @addr: Virtual address associated with pmd.
*
- * Context: The pmd range has been unmaped and TLB purged.
+ * Context: The pmd range has been unmapped and TLB purged.
* Return: 1 if clearing the entry succeeded. 0 otherwise.
*/
int pmd_free_pte_page(pmd_t *pmd, unsigned long addr)
@@ -758,6 +778,10 @@ int pmd_free_pte_page(pmd_t *pmd, unsign
pte = (pte_t *)pmd_page_vaddr(*pmd);
pmd_clear(pmd);
+
+ /* INVLPG to clear all paging-structure caches */
+ flush_tlb_kernel_range(addr, addr + PAGE_SIZE-1);
+
free_page((unsigned long)pte);
return 1;
^ permalink raw reply [flat|nested] 3+ messages in thread