[PATCH] x86/mm/cpa: set PAGE_KERNEL in __set_pages_p()

From: Hyeonggon Yoo
Date: Fri May 06 2022 - 01:22:33 EST


__set_pages_np() not only clears _PAGE_PRESENT and _PAGE_RW, but also
clears _PAGE_GLOBAL to avoid confusing _PAGE_GLOBAL as _PAGE_PROTNONE
when the PTE is not present.

Common usage for __set_pages_p() is to call it after __set_pages_np().
Therefore calling __set_pages_p() after __set_pages_np() clears
_PAGE_GLOBAL, making it unable to globally shared in TLB.

As they are called by set_direct_map_{invalid,default}_noflush(),
pages in direct map cannot be globally shared in TLB after being used by
vmalloc, secretmem, and hibernation.

So set PAGE_KERNEL isntead of __pgprot(_PAGE_PRESENT | _PAGE_RW) in
__set_pages_p().

Signed-off-by: Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx>
---
arch/x86/mm/pat/set_memory.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index abf5ed76e4b7..fcb6147c4cd4 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -2177,7 +2177,7 @@ static int __set_pages_p(struct page *page, int numpages)
struct cpa_data cpa = { .vaddr = &tempaddr,
.pgd = NULL,
.numpages = numpages,
- .mask_set = __pgprot(_PAGE_PRESENT | _PAGE_RW),
+ .mask_set = PAGE_KERNEL,
.mask_clr = __pgprot(0),
.flags = 0};

--
2.32.0