| From | "Kirill A. Shutemov" <> | Subject | [RFC, PATCH 19/22] x86/mm: Implement free_encrypt_page() | Date | Mon, 5 Mar 2018 19:26:07 +0300 |
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As on allocation of encrypted page, we need to flush cache before returning page to free pool. Failing to do this may lead to data corruption.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> --- arch/x86/mm/mktme.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)
diff --git a/arch/x86/mm/mktme.c b/arch/x86/mm/mktme.c index 1129ad25b22a..ef0eb1eb8d6e 100644 --- a/arch/x86/mm/mktme.c +++ b/arch/x86/mm/mktme.c @@ -45,6 +45,19 @@ void prep_encrypt_page(struct page *page, gfp_t gfp, unsigned int order) WARN_ONCE(gfp & __GFP_ZERO, "__GFP_ZERO is useless for encrypted pages"); } +void free_encrypt_page(struct page *page, int keyid, unsigned int order) +{ + int i; + void *v; + + for (i = 0; i < (1 << order); i++) { + v = kmap_atomic_keyid(page, keyid + i); + /* See comment in prep_encrypt_page() */ + clflush_cache_range(v, PAGE_SIZE); + kunmap_atomic(v); + } +} + struct page *__alloc_zeroed_encrypted_user_highpage(gfp_t gfp, struct vm_area_struct *vma, unsigned long vaddr) { -- 2.16.1
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