From: Evgeniy Baskov <baskov@ispras.ru>
To: Ard Biesheuvel <ardb@kernel.org>
Cc: Evgeniy Baskov <baskov@ispras.ru>, Borislav Petkov <bp@alien8.de>,
Andy Lutomirski <luto@kernel.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Alexey Khoroshilov <khoroshilov@ispras.ru>,
Peter Jones <pjones@redhat.com>,
"Limonciello, Mario" <mario.limonciello@amd.com>,
joeyli <jlee@suse.com>,
lvc-project@linuxtesting.org, x86@kernel.org,
linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-hardening@vger.kernel.org
Subject: [PATCH v3 09/24] x86/boot: Remove mapping from page fault handler
Date: Tue, 22 Nov 2022 14:12:18 +0300 [thread overview]
Message-ID: <7438db5fded11a28310267a7b51b483a5f61d0d4.1668958803.git.baskov@ispras.ru> (raw)
In-Reply-To: <cover.1668958803.git.baskov@ispras.ru>
After every implicit mapping is removed, this code is no longer needed.
Remove memory mapping from page fault handler to ensure that there are
no hidden invalid memory accesses.
Tested-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Evgeniy Baskov <baskov@ispras.ru>
---
arch/x86/boot/compressed/ident_map_64.c | 26 ++++++++++---------------
1 file changed, 10 insertions(+), 16 deletions(-)
diff --git a/arch/x86/boot/compressed/ident_map_64.c b/arch/x86/boot/compressed/ident_map_64.c
index fec795a4ce23..ba5108c58a4e 100644
--- a/arch/x86/boot/compressed/ident_map_64.c
+++ b/arch/x86/boot/compressed/ident_map_64.c
@@ -386,27 +386,21 @@ void do_boot_page_fault(struct pt_regs *regs, unsigned long error_code)
{
unsigned long address = native_read_cr2();
unsigned long end;
- bool ghcb_fault;
+ char *msg;
- ghcb_fault = sev_es_check_ghcb_fault(address);
+ if (sev_es_check_ghcb_fault(address))
+ msg = "Page-fault on GHCB page:";
+ else
+ msg = "Unexpected page-fault:";
address &= PMD_MASK;
end = address + PMD_SIZE;
/*
- * Check for unexpected error codes. Unexpected are:
- * - Faults on present pages
- * - User faults
- * - Reserved bits set
- */
- if (error_code & (X86_PF_PROT | X86_PF_USER | X86_PF_RSVD))
- do_pf_error("Unexpected page-fault:", error_code, address, regs->ip);
- else if (ghcb_fault)
- do_pf_error("Page-fault on GHCB page:", error_code, address, regs->ip);
-
- /*
- * Error code is sane - now identity map the 2M region around
- * the faulting address.
+ * Since all memory allocations are made explicit
+ * now, every page fault at this stage is an
+ * error and the error handler is there only
+ * for debug purposes.
*/
- kernel_add_identity_map(address, end, MAP_WRITE);
+ do_pf_error(msg, error_code, address, regs->ip);
}
--
2.37.4
next prev parent reply other threads:[~2022-11-22 11:14 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-22 11:12 [PATCH v3 00/24] x86_64: Improvements at compressed kernel stage Evgeniy Baskov
2022-11-22 11:12 ` [PATCH v3 01/24] x86/boot: Align vmlinuz sections on page size Evgeniy Baskov
2022-11-22 11:12 ` [PATCH v3 02/24] x86/build: Remove RWX sections and align on 4KB Evgeniy Baskov
2022-11-22 11:12 ` [PATCH v3 03/24] x86/boot: Set cr0 to known state in trampoline Evgeniy Baskov
2022-11-22 11:12 ` [PATCH v3 04/24] x86/boot: Increase boot page table size Evgeniy Baskov
2022-11-22 11:12 ` [PATCH v3 05/24] x86/boot: Support 4KB pages for identity mapping Evgeniy Baskov
2022-11-22 11:12 ` [PATCH v3 06/24] x86/boot: Setup memory protection for bzImage code Evgeniy Baskov
2022-11-22 11:12 ` [PATCH v3 07/24] x86/build: Check W^X of vmlinux during build Evgeniy Baskov
2022-11-22 11:12 ` [PATCH v3 08/24] x86/boot: Map memory explicitly Evgeniy Baskov
2022-11-22 11:12 ` Evgeniy Baskov [this message]
2022-11-22 11:12 ` [PATCH v3 10/24] efi/libstub: Move helper function to related file Evgeniy Baskov
2022-11-22 11:12 ` [PATCH v3 11/24] x86/boot: Make console interface more abstract Evgeniy Baskov
2022-11-22 11:12 ` [PATCH v3 12/24] x86/boot: Make kernel_add_identity_map() a pointer Evgeniy Baskov
2022-11-22 11:12 ` [PATCH v3 13/24] x86/boot: Split trampoline and pt init code Evgeniy Baskov
2022-11-22 11:12 ` [PATCH v3 14/24] x86/boot: Add EFI kernel extraction interface Evgeniy Baskov
2022-11-22 11:12 ` [PATCH v3 15/24] efi/x86: Support extracting kernel from libstub Evgeniy Baskov
2022-11-22 11:12 ` [PATCH v3 16/24] x86/boot: Reduce lower limit of physical KASLR Evgeniy Baskov
2022-11-22 11:12 ` [PATCH v3 17/24] x86/boot: Reduce size of the DOS stub Evgeniy Baskov
2022-11-22 11:12 ` [PATCH v3 18/24] tools/include: Add simplified version of pe.h Evgeniy Baskov
2022-11-22 11:12 ` [PATCH v3 19/24] x86/build: Cleanup tools/build.c Evgeniy Baskov
2022-11-22 11:12 ` [PATCH v3 20/24] x86/build: Make generated PE more spec compliant Evgeniy Baskov
2022-11-22 11:12 ` [PATCH v3 21/24] efi/x86: Explicitly set sections memory attributes Evgeniy Baskov
2022-11-22 11:12 ` [PATCH v3 22/24] efi/libstub: Add memory attribute protocol definitions Evgeniy Baskov
2023-01-31 8:37 ` Ard Biesheuvel
2023-01-31 10:00 ` Evgeniy Baskov
2023-01-31 10:01 ` Ard Biesheuvel
2022-11-22 11:12 ` [PATCH v3 23/24] efi/libstub: Use memory attribute protocol Evgeniy Baskov
2022-11-22 11:12 ` [PATCH v3 24/24] efi/libstub: Make memory protection warnings include newlines Evgeniy Baskov
2022-12-13 18:03 ` [PATCH v3 00/24] x86_64: Improvements at compressed kernel stage Peter Jones
2022-12-13 18:04 ` [PATCH 1/2] efi/x86: don't set unsupported memory attributes Peter Jones
2022-12-13 18:04 ` [PATCH 2/2] efi/x86: don't try to set page attributes on 0-sized regions Peter Jones
2022-12-13 18:13 ` [PATCH v3 00/24] x86_64: Improvements at compressed kernel stage Peter Jones
2022-12-13 22:16 ` Evgeniy Baskov
2022-12-14 10:09 ` Ard Biesheuvel
2022-12-14 11:49 ` Evgeniy Baskov
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