diff options
| author | Brian Gerst <brgerst@gmail.com> | 2020-06-17 18:56:24 -0400 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2020-06-18 13:09:17 +0200 |
| commit | c9a1ff316bc9b1d1806a4366d0aef6e18833ba52 (patch) | |
| tree | f2dae0b0a21105a645d90444b3effddc06504c94 /arch/x86/kernel | |
| parent | a5ce9f2bb665d1d2b31f139a02dbaa2dfbb62fa6 (diff) | |
x86/stackprotector: Pre-initialize canary for secondary CPUs
The idle tasks created for each secondary CPU already have a random stack
canary generated by fork(). Copy the canary to the percpu variable before
starting the secondary CPU which removes the need to call
boot_init_stack_canary().
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200617225624.799335-1-brgerst@gmail.com
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/smpboot.c | 14 |
1 files changed, 2 insertions, 12 deletions
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index ffbd9a3d78d8..a11bd53c6911 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -51,7 +51,6 @@ #include <linux/err.h> #include <linux/nmi.h> #include <linux/tboot.h> -#include <linux/stackprotector.h> #include <linux/gfp.h> #include <linux/cpuidle.h> #include <linux/numa.h> @@ -80,6 +79,7 @@ #include <asm/cpu_device_id.h> #include <asm/spec-ctrl.h> #include <asm/hw_irq.h> +#include <asm/stackprotector.h> /* representing HT siblings of each logical CPU */ DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_sibling_map); @@ -259,21 +259,10 @@ static void notrace start_secondary(void *unused) /* enable local interrupts */ local_irq_enable(); - /* to prevent fake stack check failure in clock setup */ - boot_init_stack_canary(); - x86_cpuinit.setup_percpu_clockev(); wmb(); cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); - - /* - * Prevent tail call to cpu_startup_entry() because the stack protector - * guard has been changed a couple of function calls up, in - * boot_init_stack_canary() and must not be checked before tail calling - * another function. - */ - prevent_tail_call_optimization(); } /** @@ -1011,6 +1000,7 @@ int common_cpu_up(unsigned int cpu, struct task_struct *idle) alternatives_enable_smp(); per_cpu(current_task, cpu) = idle; + cpu_init_stack_canary(cpu, idle); /* Initialize the interrupt stack(s) */ ret = irq_init_percpu_irqstack(cpu); |