ioremap: Update pgtable free interfaces with addr
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. Commitb6bdb7517c
("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:28ee90fe60
("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
This commit is contained in:

committed by
Thomas Gleixner

parent
f967db0b9e
commit
785a19f9d1
@@ -977,12 +977,12 @@ int pmd_clear_huge(pmd_t *pmdp)
|
||||
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);
|
||||
}
|
||||
|
Reference in New Issue
Block a user