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| author |   Andy Lutomirski <luto@kernel.org> | 2017-12-12 07:56:36 -0800 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2017-12-15 16:58:53 +0100 |
| commit | c739f930be1dd5fd949030e3475a884fe06dae9b (patch) | |
| tree | 64721708d3ac7a0b35b4c0256b6f451fd461d733 /arch/x86/kernel/traps.c | |
| parent | objtool: Resync objtool's instruction decoder source code copy with the kernel's latest version (diff) | |
| download | linux-dev-c739f930be1dd5fd949030e3475a884fe06dae9b.tar.xz linux-dev-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/x86/kernel/traps.c')
| -rw-r--r-- | arch/x86/kernel/traps.c | 2 |
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) { |