This is a note to let you know that I've just added the patch titled
arm: KVM: fix possible misalignment of PGDs and bounce page
to the 3.14-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:
arm-kvm-fix-possible-misalignment-of-pgds-and-bounce-page.patch
and it can be found in the queue-3.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 5d4e08c45a6cf8f1ab3c7fa375007635ac569165 Mon Sep 17 00:00:00 2001
From: Mark Salter <msalter@xxxxxxxxxx>
Date: Fri, 28 Mar 2014 14:25:19 +0000
Subject: arm: KVM: fix possible misalignment of PGDs and bounce page
From: Mark Salter <msalter@xxxxxxxxxx>
commit 5d4e08c45a6cf8f1ab3c7fa375007635ac569165 upstream.
The kvm/mmu code shared by arm and arm64 uses kalloc() to allocate
a bounce page (if hypervisor init code crosses page boundary) and
hypervisor PGDs. The problem is that kalloc() does not guarantee
the proper alignment. In the case of the bounce page, the page sized
buffer allocated may also cross a page boundary negating the purpose
and leading to a hang during kvm initialization. Likewise the PGDs
allocated may not meet the minimum alignment requirements of the
underlying MMU. This patch uses __get_free_page() to guarantee the
worst case alignment needs of the bounce page and PGDs on both arm
and arm64.
Signed-off-by: Mark Salter <msalter@xxxxxxxxxx>
Acked-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arm/kvm/mmu.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -42,6 +42,8 @@ static unsigned long hyp_idmap_start;
static unsigned long hyp_idmap_end;
static phys_addr_t hyp_idmap_vector;
+#define pgd_order get_order(PTRS_PER_PGD * sizeof(pgd_t))
+
#define kvm_pmd_huge(_x) (pmd_huge(_x) || pmd_trans_huge(_x))
static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
@@ -199,14 +201,14 @@ void free_boot_hyp_pgd(void)
if (boot_hyp_pgd) {
unmap_range(NULL, boot_hyp_pgd, hyp_idmap_start, PAGE_SIZE);
unmap_range(NULL, boot_hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE);
- kfree(boot_hyp_pgd);
+ free_pages((unsigned long)boot_hyp_pgd, pgd_order);
boot_hyp_pgd = NULL;
}
if (hyp_pgd)
unmap_range(NULL, hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE);
- kfree(init_bounce_page);
+ free_page((unsigned long)init_bounce_page);
init_bounce_page = NULL;
mutex_unlock(&kvm_hyp_pgd_mutex);
@@ -236,7 +238,7 @@ void free_hyp_pgds(void)
for (addr = VMALLOC_START; is_vmalloc_addr((void*)addr); addr += PGDIR_SIZE)
unmap_range(NULL, hyp_pgd, KERN_TO_HYP(addr), PGDIR_SIZE);
- kfree(hyp_pgd);
+ free_pages((unsigned long)hyp_pgd, pgd_order);
hyp_pgd = NULL;
}
@@ -930,7 +932,7 @@ int kvm_mmu_init(void)
size_t len = __hyp_idmap_text_end - __hyp_idmap_text_start;
phys_addr_t phys_base;
- init_bounce_page = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ init_bounce_page = (void *)__get_free_page(GFP_KERNEL);
if (!init_bounce_page) {
kvm_err("Couldn't allocate HYP init bounce page\n");
err = -ENOMEM;
@@ -956,8 +958,9 @@ int kvm_mmu_init(void)
(unsigned long)phys_base);
}
- hyp_pgd = kzalloc(PTRS_PER_PGD * sizeof(pgd_t), GFP_KERNEL);
- boot_hyp_pgd = kzalloc(PTRS_PER_PGD * sizeof(pgd_t), GFP_KERNEL);
+ hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, pgd_order);
+ boot_hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, pgd_order);
+
if (!hyp_pgd || !boot_hyp_pgd) {
kvm_err("Hyp mode PGD not allocated\n");
err = -ENOMEM;
Patches currently in stable-queue which might be from msalter@xxxxxxxxxx are
queue-3.14/arm-kvm-fix-possible-misalignment-of-pgds-and-bounce-page.patch
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