summaryrefslogtreecommitdiff
path: root/include/linux
diff options
context:
space:
mode:
authorMatthew Wilcox (Oracle) <willy@infradead.org>2023-09-20 07:09:58 +0300
committerAndrew Morton <akpm@linux-foundation.org>2023-09-30 03:20:46 +0300
commitce60f27bb62dfeb1bf827350520f34abc84e0933 (patch)
treeba2bb32d49a6ed1df73a1f1e62392929b12c5e1f /include/linux
parenta501a0703044f00180d7697b32cacd7ff46d02d8 (diff)
downloadlinux-ce60f27bb62dfeb1bf827350520f34abc84e0933.tar.xz
mm: abstract moving to the next PFN
In order to fix the L1TF vulnerability, x86 can invert the PTE bits for PROT_NONE VMAs, which means we cannot move from one PTE to the next by adding 1 to the PFN field of the PTE. This results in the BUG reported at [1]. Abstract advancing the PTE to the next PFN through a pte_next_pfn() function/macro. Link: https://lkml.kernel.org/r/20230920040958.866520-1-willy@infradead.org Fixes: bcc6cc832573 ("mm: add default definition of set_ptes()") Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reported-by: syzbot+55cc72f8cc3a549119df@syzkaller.appspotmail.com Closes: https://lkml.kernel.org/r/000000000000d099fa0604f03351@google.com [1] Reviewed-by: Yin Fengwei <fengwei.yin@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/pgtable.h10
1 files changed, 9 insertions, 1 deletions
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index 1fba072b3dac..af7639c3b0a3 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -206,6 +206,14 @@ static inline int pmd_young(pmd_t pmd)
#endif
#ifndef set_ptes
+
+#ifndef pte_next_pfn
+static inline pte_t pte_next_pfn(pte_t pte)
+{
+ return __pte(pte_val(pte) + (1UL << PFN_PTE_SHIFT));
+}
+#endif
+
/**
* set_ptes - Map consecutive pages to a contiguous range of addresses.
* @mm: Address space to map the pages into.
@@ -231,7 +239,7 @@ static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
if (--nr == 0)
break;
ptep++;
- pte = __pte(pte_val(pte) + (1UL << PFN_PTE_SHIFT));
+ pte = pte_next_pfn(pte);
}
arch_leave_lazy_mmu_mode();
}