From: tip-bot for Andy Lutomirski <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, torvalds@linux-foundation.org,
David.Laight@aculab.com, tglx@linutronix.de, mingo@kernel.org,
kirill@shutemov.name, bp@alien8.de,
kirill.shutemov@linux.intel.com, dave.hansen@intel.com,
keescook@chromium.org, hpa@zytor.com, luto@kernel.org,
peterz@infradead.org, brgerst@gmail.com
Subject: [tip:x86/urgent] x86/espfix/64: Fix espfix double-fault handling on 5-level systems
Date: Fri, 15 Dec 2017 10:34:12 -0800 [thread overview]
Message-ID: <tip-c739f930be1dd5fd949030e3475a884fe06dae9b@git.kernel.org> (raw)
In-Reply-To: <24c898b4f44fdf8c22d93703850fb384ef87cfdc.1513035461.git.luto@kernel.org>
Commit-ID: c739f930be1dd5fd949030e3475a884fe06dae9b
Gitweb: https://git.kernel.org/tip/c739f930be1dd5fd949030e3475a884fe06dae9b
Author: Andy Lutomirski <luto@kernel.org>
AuthorDate: Tue, 12 Dec 2017 07:56:36 -0800
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Fri, 15 Dec 2017 16:58:53 +0100
x86/espfix/64: Fix espfix double-fault handling on 5-level systems
Using PGDIR_SHIFT to identify espfix64 addresses on 5-level systems
was wrong, and it resulted in panics due to unhandled double faults.
Use P4D_SHIFT instead, which is correct on 4-level and 5-level
machines.
This fixes a panic when running x86 selftests on 5-level machines.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Fixes: 1d33b219563f ("x86/espfix: Add support for 5-level paging")
Link: http://lkml.kernel.org/r/24c898b4f44fdf8c22d93703850fb384ef87cfdc.1513035461.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/kernel/traps.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index b7b0f74..c751518 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -355,7 +355,7 @@ dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code)
*
* No need for ist_enter here because we don't use RCU.
*/
- if (((long)regs->sp >> PGDIR_SHIFT) == ESPFIX_PGD_ENTRY &&
+ if (((long)regs->sp >> P4D_SHIFT) == ESPFIX_PGD_ENTRY &&
regs->cs == __KERNEL_CS &&
regs->ip == (unsigned long)native_irq_return_iret)
{
next prev parent reply other threads:[~2017-12-15 19:02 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-11 23:40 [PATCH PTI v3 00/10] Clean up pgd handling and fix VSYSCALL and LDT Andy Lutomirski
2017-12-12 10:09 ` Ingo Molnar
2017-12-12 15:58 ` Andy Lutomirski
2017-12-12 16:13 ` Borislav Petkov
2017-12-12 16:14 ` Juergen Gross
2017-12-12 16:20 ` Borislav Petkov
2017-12-12 15:56 ` [PATCH PTI v3 01/10] x86/espfix/64: Fix espfix double-fault handling on 5-level systems Andy Lutomirski
2017-12-12 17:18 ` Kirill A. Shutemov
2017-12-15 18:34 ` tip-bot for Andy Lutomirski [this message]
2017-12-12 15:56 ` [PATCH PTI v3 02/10] x86/pti: Vastly simplify pgd synchronization Andy Lutomirski
2017-12-12 15:56 ` [PATCH PTI v3 03/10] x86/pti/64: Fix ESPFIX64 user mapping Andy Lutomirski
2017-12-13 13:12 ` Kirill A. Shutemov
2017-12-13 17:01 ` Andy Lutomirski
2017-12-14 14:10 ` Kirill A. Shutemov
2017-12-14 16:18 ` Andy Lutomirski
2017-12-12 15:56 ` [PATCH PTI v3 04/10] Revert "x86/mm/pti: Disable native VSYSCALL" Andy Lutomirski
2017-12-12 15:56 ` [PATCH PTI v3 05/10] x86/vsyscall/64: Explicitly set _PAGE_USER in the pagetable hierarchy Andy Lutomirski
2017-12-12 15:56 ` [PATCH PTI v3 06/10] x86/vsyscall/64: Warn and fail vsyscall emulation in NATIVE mode Andy Lutomirski
2017-12-12 15:56 ` [PATCH PTI v3 07/10] x86/pti: Map the vsyscall page if needed Andy Lutomirski
2017-12-12 15:56 ` [PATCH PTI v3 08/10] x86/mm/64: Improve the memory map documentation Andy Lutomirski
2017-12-12 15:56 ` [PATCH PTI v3 09/10] x86/mm/64: Make a full PGD-entry size hole in the memory map Andy Lutomirski
2017-12-13 13:17 ` Kirill A. Shutemov
2017-12-13 17:04 ` Andy Lutomirski
2017-12-12 15:56 ` [PATCH PTI v3 10/10] x86/pti: Put the LDT in its own PGD if PTI is on Andy Lutomirski
2017-12-15 22:54 ` Thomas Gleixner
2017-12-16 0:39 ` Thomas Gleixner
2017-12-16 6:41 ` Andy Lutomirski
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