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bh=17Ab6P2j5OVF8Gr3Yg5Qn24MvwgRH/J1nkWqaHudOc0=; b=FO6kU4TjQRsfkE7Go9HFs/q+JM x69oKhqVSUCygDweJvQjxbYJO6KdaGYKozVUy/YUgqW1/EPfX9jjsC+ObO0o5GSyOWTMw6Lz9QSAU sopjRdId2JNgSTWycz8MxVexI5ptju0l94H50ooMxsHjSlO/CrpnE+RukfWHQ47Ped+RYPxQYIKhu GpkeK8oExTOG2HjvjFleOgeUXQpcYiffQ4Jt8HAP5KiHskraGF7wFKom1+j/WtEe599nbGfDS2DK+ JGcgty/joPOfR7vLD7YQyb3n+9RfH4fxye15dQWSGkGJqMXA/2wpHtY3JAAvobsHHkJHzqE5eRBGN dnGNjKtw==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1qioHS-003aDn-F8; Wed, 20 Sep 2023 03:53:38 +0000 From: "Matthew Wilcox (Oracle)" To: Andrew Morton Cc: "Matthew Wilcox (Oracle)" , linux-mm@kvack.org, Yin Fengwei , Dave Hansen , David Hildenbrand , Thomas Gleixner , syzbot+55cc72f8cc3a549119df@syzkaller.appspotmail.com Subject: [PATCH 2/2] mm: Abstract moving to the next PFN Date: Wed, 20 Sep 2023 04:53:36 +0100 Message-Id: <20230920035336.854212-2-willy@infradead.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20230920035336.854212-1-willy@infradead.org> References: <20230920035336.854212-1-willy@infradead.org> MIME-Version: 1.0 X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: B139B1C0006 X-Stat-Signature: q3zpywjtddw7enczd36jf1g1wtcbimhs X-Rspam-User: X-HE-Tag: 1695182024-552750 X-HE-Meta: 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 enCQRuSG a6dlXA/Yc+7wtjbst8Tgs3w565wRxksbTQIMwzgj0He+U9QKGnbtq8qG0DdcgPb63L5vHQEyNzME5zO/8b1PGxLX5oMXOk3bPLe4qTo5kNcAfgwlrUCPM1mhhE9IjYq65JyNGvgVIRe/DAQXKnMnnFe1aJOifBN0cAI/ZUURcdLD1LR76f1Ul+BQN8AR/++Ox1h8mg3Qn/EnyobrvgWz2fuPf89bIK1GXoVMjeb5S7oQcsYUUdeIsW03mAjEsCzY4SNW7G/p0nSsL+rWRZuoCxyXTi7P+v6Hy9aiyvqWgNaTmeylypPR2GWkz3HpxzSJM0eTwy+y1T70AsuYgKjg8R22KaA== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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. Abstract advancing the PTE to the next PFN through a pte_next_pfn() function/macro. Signed-off-by: Matthew Wilcox (Oracle) Fixes: bcc6cc832573 ("mm: add default definition of set_ptes()") Reported-by: syzbot+55cc72f8cc3a549119df@syzkaller.appspotmail.com --- arch/x86/include/asm/pgtable.h | 8 ++++++++ include/linux/pgtable.h | 6 +++++- 2 files changed, 13 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index d6ad98ca1288..e02b179ec659 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -955,6 +955,14 @@ static inline int pte_same(pte_t a, pte_t b) return a.pte == b.pte; } +static inline pte_t pte_next_pfn(pte_t pte) +{ + if (__pte_needs_invert(pte_val(pte))) + return __pte(pte_val(pte) - (1UL << PFN_PTE_SHIFT)); + return __pte(pte_val(pte) + (1UL << PFN_PTE_SHIFT)); +} +#define pte_next_pfn pte_next_pfn + static inline int pte_present(pte_t a) { return pte_flags(a) & (_PAGE_PRESENT | _PAGE_PROTNONE); diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index 1fba072b3dac..5bdf78aa7852 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -205,6 +205,10 @@ static inline int pmd_young(pmd_t pmd) #define arch_flush_lazy_mmu_mode() do {} while (0) #endif +#ifndef pte_next_pfn +#define pte_next_pfn(pte) ((pte) + (1UL << PFN_PTE_SHIFT)) +#endif + #ifndef set_ptes /** * set_ptes - Map consecutive pages to a contiguous range of addresses. @@ -231,7 +235,7 @@ 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(); }