[tip: x86/mm] x86/mm: Recompute physical address for every page of per-CPU CEA mapping

From: tip-bot2 for Sean Christopherson
Date: Sat Dec 17 2022 - 13:56:18 EST


The following commit has been merged into the x86/mm branch of tip:

Commit-ID: 80d72a8f76e8f3f0b5a70b8c7022578e17bde8e7
Gitweb: https://git.kernel.org/tip/80d72a8f76e8f3f0b5a70b8c7022578e17bde8e7
Author: Sean Christopherson <seanjc@xxxxxxxxxx>
AuthorDate: Thu, 10 Nov 2022 20:35:00
Committer: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
CommitterDate: Thu, 15 Dec 2022 10:37:28 -08:00

x86/mm: Recompute physical address for every page of per-CPU CEA mapping

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")
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx>
Link: https://lkml.kernel.org/r/20221110203504.1985010-2-seanjc@xxxxxxxxxx
---
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 dff9001..d831aae 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)