4.14-stable review patch. If anyone has any objections, please let me know.
------------------ From: Andy Lutomirski <l...@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 <l...@kernel.org> Reviewed-by: Borislav Petkov <b...@suse.de> Cc: Borislav Petkov <bpet...@suse.de> Cc: Brian Gerst <brge...@gmail.com> Cc: Dave Hansen <dave.han...@intel.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Link: http://lkml.kernel.org/r/e5e370a7e6e4fddd1c4e4cf619765d96bb874b21.1509609304.git.l...@kernel.org Signed-off-by: Ingo Molnar <mi...@kernel.org> Signed-off-by: Greg Kroah-Hartman <gre...@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
