On Tue, 03 Jan 2023 16:27:32 PST (-0800), mike.kravetz@xxxxxxxxxx wrote:
zap_page_range was originally designed to unmap pages within an address
range that could span multiple vmas. While working on [1], it was
discovered that all callers of zap_page_range pass a range entirely within
a single vma. In addition, the mmu notification call within zap_page
range does not correctly handle ranges that span multiple vmas. When
crossing a vma boundary, a new mmu_notifier_range_init/end call pair
with the new vma should be made.
Instead of fixing zap_page_range, do the following:
- Create a new routine zap_vma_pages() that will remove all pages within
the passed vma. Most users of zap_page_range pass the entire vma and
can use this new routine.
- For callers of zap_page_range not passing the entire vma, instead call
zap_page_range_single().
- Remove zap_page_range.
[1] https://lore.kernel.org/linux-mm/20221114235507.294320-2-mike.kravetz@xxxxxxxxxx/
Suggested-by: Peter Xu <peterx@xxxxxxxxxx>
Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
[...]
diff --git a/arch/riscv/kernel/vdso.c b/arch/riscv/kernel/vdso.c
index e410275918ac..5c30212d8d1c 100644
--- a/arch/riscv/kernel/vdso.c
+++ b/arch/riscv/kernel/vdso.c
@@ -124,13 +124,11 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns)
mmap_read_lock(mm);
for_each_vma(vmi, vma) {
- unsigned long size = vma->vm_end - vma->vm_start;
-
if (vma_is_special_mapping(vma, vdso_info.dm))
- zap_page_range(vma, vma->vm_start, size);
+ zap_vma_pages(vma);
#ifdef CONFIG_COMPAT
if (vma_is_special_mapping(vma, compat_vdso_info.dm))
- zap_page_range(vma, vma->vm_start, size);
+ zap_vma_pages(vma);
#endif
}
Acked-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx> # RISC-V
Thanks!
