diff options
| author | Chintan Pandya <cpandya@codeaurora.org> | 2018-06-27 08:13:47 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-08-17 20:56:45 +0200 |
| commit | 29f475cbff9b56c83821344b02d5152847839bc2 (patch) | |
| tree | 016e0dc0991575c8eee8878e228ea3a041cb01d6 /arch/arm64/mm | |
| parent | 17c1e0b1f6a161cc4f533d4869ff574273dbfe8d (diff) | |
ioremap: Update pgtable free interfaces with addr
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@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@suse.com
Cc: akpm@linux-foundation.org
Cc: hpa@zytor.com
Cc: linux-mm@kvack.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: Will Deacon <will.deacon@arm.com>
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/20180627141348.21777-3-toshi.kani@hpe.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm64/mm')
| -rw-r--r-- | arch/arm64/mm/mmu.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 51ac84e0812d..e9d96b028766 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -699,12 +699,12 @@ void *__init fixmap_remap_fdt(phys_addr_t dt_phys) } #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP -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); } |