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Reply-To: Sean Christopherson <seanjc@google.com>
Date:   Thu, 10 Nov 2022 20:35:00 +0000
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Subject: [PATCH v2 1/5] x86/mm: Recompute physical address for every page of
 per-CPU CEA mapping
From:   Sean Christopherson <seanjc@google.com>
To:     Dave Hansen <dave.hansen@linux.intel.com>,
        Andy Lutomirski <luto@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        x86@kernel.org, Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc:     "H. Peter Anvin" <hpa@zytor.com>,
        Alexander Potapenko <glider@google.com>,
        Andrey Konovalov <andreyknvl@gmail.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Vincenzo Frascino <vincenzo.frascino@arm.com>,
        linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com,
        Sean Christopherson <seanjc@google.com>,
        syzbot+ffb4f000dc2872c93f62@syzkaller.appspotmail.com,
        syzbot+8cdd16fd5a6c0565e227@syzkaller.appspotmail.com
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Precedence: bulk

Recompute the physical address for each per-CPU page in the CPU entry
area, a recent commit inadvertantly modified cea_map_percpu_pages() such
that every PTE is mapped to the physical address of the first page.

Fixes: 9fd429c28073 ("x86/kasan: Map shadow for percpu pages on demand")
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/mm/cpu_entry_area.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/mm/cpu_entry_area.c b/arch/x86/mm/cpu_entry_area.c
index dff9001e5e12..d831aae94b41 100644
--- a/arch/x86/mm/cpu_entry_area.c
+++ b/arch/x86/mm/cpu_entry_area.c
@@ -97,7 +97,7 @@ cea_map_percpu_pages(void *cea_vaddr, void *ptr, int pages, pgprot_t prot)
 					early_pfn_to_nid(PFN_DOWN(pa)));
 
 	for ( ; pages; pages--, cea_vaddr+= PAGE_SIZE, ptr += PAGE_SIZE)
-		cea_set_pte(cea_vaddr, pa, prot);
+		cea_set_pte(cea_vaddr, per_cpu_ptr_to_phys(ptr), prot);
 }
 
 static void __init percpu_setup_debug_store(unsigned int cpu)
-- 
2.38.1.431.g37b22c650d-goog