| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.14 052/159] x86/entry/32: Fix cpu_current_top_of_stack initialization at boot | Date | Fri, 22 Dec 2017 09:45:37 +0100 |
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4.14-stable review patch. If anyone has any objections, please let me know.
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From: Andy Lutomirski <luto@kernel.org>
commit cd493a6deb8b78eca280d05f7fa73fd69403ae29 upstream.
cpu_current_top_of_stack's initialization forgot about TOP_OF_KERNEL_STACK_PADDING. This bug didn't matter because the idle threads never enter user mode.
Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/e5e370a7e6e4fddd1c4e4cf619765d96bb874b21.1509609304.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- arch/x86/kernel/smpboot.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
--- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -962,8 +962,7 @@ void common_cpu_up(unsigned int cpu, str #ifdef CONFIG_X86_32 /* Stack for startup_32 can be just as for start_secondary onwards */ irq_ctx_init(cpu); - per_cpu(cpu_current_top_of_stack, cpu) = - (unsigned long)task_stack_page(idle) + THREAD_SIZE; + per_cpu(cpu_current_top_of_stack, cpu) = task_top_of_stack(idle); #else initial_gs = per_cpu_offset(cpu); #endif
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