From: Rick Edgecombe <rick.p.edgecombe@intel.com>
To: dave.hansen@intel.com, luto@kernel.org, peterz@infradead.org,
x86@kernel.org, akpm@linux-foundation.org, keescook@chromium.org,
shakeelb@google.com, vbabka@suse.cz, rppt@kernel.org
Cc: Rick Edgecombe <rick.p.edgecombe@intel.com>,
linux-mm@kvack.org, linux-hardening@vger.kernel.org,
kernel-hardening@lists.openwall.com, ira.weiny@intel.com,
dan.j.williams@intel.com, linux-kernel@vger.kernel.org
Subject: [RFC PATCH v2 14/19] x86/efi: Toggle table protections when copying
Date: Mon, 30 Aug 2021 16:59:22 -0700 [thread overview]
Message-ID: <20210830235927.6443-15-rick.p.edgecombe@intel.com> (raw)
In-Reply-To: <20210830235927.6443-1-rick.p.edgecombe@intel.com>
Toggle page table writability when copying page tables in
efi_sync_low_kernel_mappings(). These page tables will not be protected
until after init, but later on they will not be writable.
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
---
arch/x86/platform/efi/efi_64.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index 7515e78ef898..7a5c81450fa4 100644
--- a/arch/x86/platform/efi/efi_64.c
+++ b/arch/x86/platform/efi/efi_64.c
@@ -116,7 +116,9 @@ void efi_sync_low_kernel_mappings(void)
pgd_k = pgd_offset_k(PAGE_OFFSET);
num_entries = pgd_index(EFI_VA_END) - pgd_index(PAGE_OFFSET);
+ enable_pgtable_write();
memcpy(pgd_efi, pgd_k, sizeof(pgd_t) * num_entries);
+ disable_pgtable_write();
pgd_efi = efi_pgd + pgd_index(EFI_VA_END);
pgd_k = pgd_offset_k(EFI_VA_END);
@@ -124,7 +126,9 @@ void efi_sync_low_kernel_mappings(void)
p4d_k = p4d_offset(pgd_k, 0);
num_entries = p4d_index(EFI_VA_END);
+ enable_pgtable_write();
memcpy(p4d_efi, p4d_k, sizeof(p4d_t) * num_entries);
+ disable_pgtable_write();
/*
* We share all the PUD entries apart from those that map the
@@ -139,13 +143,17 @@ void efi_sync_low_kernel_mappings(void)
pud_k = pud_offset(p4d_k, 0);
num_entries = pud_index(EFI_VA_END);
+ enable_pgtable_write();
memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
+ disable_pgtable_write();
pud_efi = pud_offset(p4d_efi, EFI_VA_START);
pud_k = pud_offset(p4d_k, EFI_VA_START);
num_entries = PTRS_PER_PUD - pud_index(EFI_VA_START);
+ enable_pgtable_write();
memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
+ disable_pgtable_write();
}
/*
--
2.17.1
next prev parent reply other threads:[~2021-08-31 0:00 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-30 23:59 [RFC PATCH v2 00/19] PKS write protected page tables Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 01/19] list: Support getting most recent element in list_lru Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 02/19] list: Support list head not in object for list_lru Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 03/19] x86/mm/cpa: Add grouped page allocations Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 04/19] mm: Explicitly zero page table lock ptr Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 05/19] x86, mm: Use cache of page tables Rick Edgecombe
2021-08-31 8:40 ` Mike Rapoport
2021-08-31 19:09 ` Edgecombe, Rick P
2021-08-30 23:59 ` [RFC PATCH v2 06/19] x86/mm/cpa: Add perm callbacks to grouped pages Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 07/19] x86/cpufeatures: Add feature for pks tables Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 08/19] x86/mm/cpa: Add get_grouped_page_atomic() Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 09/19] x86/mm: Support GFP_ATOMIC in alloc_table_node() Rick Edgecombe
2021-08-31 8:32 ` Mike Rapoport
2021-08-30 23:59 ` [RFC PATCH v2 10/19] x86/mm: Use alloc_table() for fill_pte(), etc Rick Edgecombe
2021-08-31 8:47 ` Mike Rapoport
2021-08-31 18:48 ` Edgecombe, Rick P
2021-08-30 23:59 ` [RFC PATCH v2 11/19] mm/sparsemem: Use alloc_table() for table allocations Rick Edgecombe
2021-08-31 8:55 ` Mike Rapoport
2021-08-31 18:25 ` Edgecombe, Rick P
2021-09-01 7:22 ` Mike Rapoport
2021-09-02 13:56 ` Vlastimil Babka
2021-08-30 23:59 ` [RFC PATCH v2 12/19] x86/mm: Use free_table in unmap path Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 13/19] mm/debug_vm_page_table: Use setters instead of WRITE_ONCE Rick Edgecombe
2021-08-30 23:59 ` Rick Edgecombe [this message]
2021-08-30 23:59 ` [RFC PATCH v2 15/19] x86/mm/cpa: Add set_memory_pks() Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 16/19] x86/mm: Protect page tables with PKS Rick Edgecombe
2021-08-31 8:56 ` Mike Rapoport
2021-08-31 17:55 ` Edgecombe, Rick P
2021-08-30 23:59 ` [RFC PATCH v2 17/19] x86/mm/cpa: PKS protect direct map page tables Rick Edgecombe
2021-08-31 10:14 ` Mike Rapoport
2021-08-31 17:58 ` Edgecombe, Rick P
2021-08-30 23:59 ` [RFC PATCH v2 18/19] x86/mm: Add PKS table soft mode Rick Edgecombe
2021-08-31 3:49 ` Randy Dunlap
2021-08-31 17:55 ` Edgecombe, Rick P
2021-08-30 23:59 ` [RFC PATCH v2 19/19] x86/mm: Add PKS table debug checking Rick Edgecombe
2024-03-14 16:27 ` [RFC PATCH v2 00/19] PKS write protected page tables Kees Cook
2024-03-14 17:10 ` Edgecombe, Rick P
2024-03-14 18:25 ` Ira Weiny
2024-03-16 3:14 ` Boris Lukashev
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