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authorAndy Lutomirski <luto@kernel.org>2017-12-12 16:56:36 +0100
committerIngo Molnar <mingo@kernel.org>2017-12-15 16:58:53 +0100
commitc739f930be1dd5fd949030e3475a884fe06dae9b (patch)
tree64721708d3ac7a0b35b4c0256b6f451fd461d733 /arch
parentobjtool: Resync objtool's instruction decoder source code copy with the kerne... (diff)
downloadlinux-c739f930be1dd5fd949030e3475a884fe06dae9b.tar.xz
linux-c739f930be1dd5fd949030e3475a884fe06dae9b.zip
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>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/traps.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index b7b0f74a2150..c751518936ac 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)
{