[PATCH v3 5/7] x86/mm/32: Implement arch_sync_kernel_mappings()

Joerg Roedel
2020-05-15T14:00:38Z

From: Joerg Roedel <jroedel@suse.de>

Implement the function to sync changes in vmalloc and ioremap ranges
to all page-tables.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
---
arch/x86/include/asm/pgtable-2level_types.h | 2 ++
arch/x86/include/asm/pgtable-3level_types.h | 2 ++
arch/x86/mm/fault.c | 25 +++++++++++++--------
3 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/arch/x86/include/asm/pgtable-2level_types.h b/arch/x86/include/asm/pgtable-2level_types.h
index 6deb6cd236e3..7f6ccff0ba72 100644
--- a/arch/x86/include/asm/pgtable-2level_types.h
+++ b/arch/x86/include/asm/pgtable-2level_types.h
@@ -20,6 +20,8 @@ typedef union {

#define SHARED_KERNEL_PMD 0

+#define ARCH_PAGE_TABLE_SYNC_MASK PGTBL_PMD_MODIFIED
+
/*
* traditional i386 two-level paging structure:
*/
diff --git a/arch/x86/include/asm/pgtable-3level_types.h b/arch/x86/include/asm/pgtable-3level_types.h
index 33845d36897c..80fbb4a9ed87 100644
--- a/arch/x86/include/asm/pgtable-3level_types.h
+++ b/arch/x86/include/asm/pgtable-3level_types.h
@@ -27,6 +27,8 @@ typedef union {
#define SHARED_KERNEL_PMD (!static_cpu_has(X86_FEATURE_PTI))
#endif

+#define ARCH_PAGE_TABLE_SYNC_MASK (SHARED_KERNEL_PMD ? 0 : PGTBL_PMD_MODIFIED)
+
/*
* PGDIR_SHIFT determines what a top-level page table entry can map
*/
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index a51df516b87b..edeb2adaf31f 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -190,16 +190,13 @@ static inline pmd_t *vmalloc_sync_one(pgd_t *pgd, unsigned long address)
return pmd_k;
}

-static void vmalloc_sync(void)
+void arch_sync_kernel_mappings(unsigned long start, unsigned long end)
{
- unsigned long address;
-
- if (SHARED_KERNEL_PMD)
- return;
+ unsigned long addr;

- for (address = VMALLOC_START & PMD_MASK;
- address >= TASK_SIZE_MAX && address < VMALLOC_END;
- address += PMD_SIZE) {
+ for (addr = start & PMD_MASK;
+ addr >= TASK_SIZE_MAX && addr < VMALLOC_END;
+ addr += PMD_SIZE) {
struct page *page;

spin_lock(&pgd_lock);
@@ -210,13 +207,23 @@ static void vmalloc_sync(void)
pgt_lock = &pgd_page_get_mm(page)->page_table_lock;

spin_lock(pgt_lock);
- vmalloc_sync_one(page_address(page), address);
+ vmalloc_sync_one(page_address(page), addr);
spin_unlock(pgt_lock);
}
spin_unlock(&pgd_lock);
}
}

+static void vmalloc_sync(void)
+{
+ unsigned long address;
+
+ if (SHARED_KERNEL_PMD)
+ return;
+
+ arch_sync_kernel_mappings(VMALLOC_START, VMALLOC_END);
+}
+
void vmalloc_sync_mappings(void)
{
vmalloc_sync();
--
2.17.1