@@ -682,24 +682,44 @@ 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;
@@ -710,7 +730,7 @@ 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)
@@ -722,6 +742,10 @@ 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;
This is a note to let you know that I've just added the patch titled x86/mm: Add TLB purge to free pmd/pte page interfaces to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: x86-mm-add-tlb-purge-to-free-pmd-pte-page-interfaces.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@vger.kernel.org> know about it. From 5e0fb5df2ee871b841f96f9cb6a7f2784e96aa4e Mon Sep 17 00:00:00 2001 From: Toshi Kani <toshi.kani@hpe.com> Date: Wed, 27 Jun 2018 08:13:48 -0600 Subject: x86/mm: Add TLB purge to free pmd/pte page interfaces 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@suse.com Cc: akpm@linux-foundation.org Cc: hpa@zytor.com Cc: cpandya@codeaurora.org Cc: linux-mm@kvack.org Cc: linux-arm-kernel@lists.infradead.org Cc: Joerg Roedel <joro@8bytes.org> Cc: stable@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@hpe.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- arch/x86/mm/pgtable.c | 38 +++++++++++++++++++++++++++++++------- 1 file changed, 31 insertions(+), 7 deletions(-) Patches currently in stable-queue which might be from toshi.kani@hpe.com are queue-4.4/x86-mm-disable-ioremap-free-page-handling-on-x86-pae.patch queue-4.4/ioremap-update-pgtable-free-interfaces-with-addr.patch queue-4.4/x86-mm-add-tlb-purge-to-free-pmd-pte-page-interfaces.patch