diff options
| -rw-r--r-- | arch/x86/include/asm/stackprotector.h | 12 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/bugs.c | 13 | ||||
| -rw-r--r-- | arch/x86/kernel/smpboot.c | 14 | ||||
| -rw-r--r-- | arch/x86/xen/smp_pv.c | 2 |
4 files changed, 18 insertions, 23 deletions
diff --git a/arch/x86/include/asm/stackprotector.h b/arch/x86/include/asm/stackprotector.h index 9804a7957f4e..7fb482f0f25b 100644 --- a/arch/x86/include/asm/stackprotector.h +++ b/arch/x86/include/asm/stackprotector.h @@ -90,6 +90,15 @@ static __always_inline void boot_init_stack_canary(void) #endif } +static inline void cpu_init_stack_canary(int cpu, struct task_struct *idle) +{ +#ifdef CONFIG_X86_64 + per_cpu(fixed_percpu_data.stack_canary, cpu) = idle->stack_canary; +#else + per_cpu(stack_canary.canary, cpu) = idle->stack_canary; +#endif +} + static inline void setup_stack_canary_segment(int cpu) { #ifdef CONFIG_X86_32 @@ -119,6 +128,9 @@ static inline void load_stack_canary_segment(void) static inline void setup_stack_canary_segment(int cpu) { } +static inline void cpu_init_stack_canary(int cpu, struct task_struct *idle) +{ } + static inline void load_stack_canary_segment(void) { #ifdef CONFIG_X86_32 diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 0b71970d2d3d..7beaefa9d198 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -763,10 +763,12 @@ spectre_v2_user_select_mitigation(enum spectre_v2_mitigation_cmd v2_cmd) } /* - * If enhanced IBRS is enabled or SMT impossible, STIBP is not + * If no STIBP, enhanced IBRS is enabled or SMT impossible, STIBP is not * required. */ - if (!smt_possible || spectre_v2_enabled == SPECTRE_V2_IBRS_ENHANCED) + if (!boot_cpu_has(X86_FEATURE_STIBP) || + !smt_possible || + spectre_v2_enabled == SPECTRE_V2_IBRS_ENHANCED) return; /* @@ -778,12 +780,6 @@ spectre_v2_user_select_mitigation(enum spectre_v2_mitigation_cmd v2_cmd) boot_cpu_has(X86_FEATURE_AMD_STIBP_ALWAYS_ON)) mode = SPECTRE_V2_USER_STRICT_PREFERRED; - /* - * If STIBP is not available, clear the STIBP mode. - */ - if (!boot_cpu_has(X86_FEATURE_STIBP)) - mode = SPECTRE_V2_USER_NONE; - spectre_v2_user_stibp = mode; set_mode: @@ -1270,7 +1266,6 @@ static int ib_prctl_set(struct task_struct *task, unsigned long ctrl) * Indirect branch speculation is always disabled in strict * mode. It can neither be enabled if it was force-disabled * by a previous prctl call. - */ if (spectre_v2_user_ibpb == SPECTRE_V2_USER_STRICT || spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT || 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); diff --git a/arch/x86/xen/smp_pv.c b/arch/x86/xen/smp_pv.c index 171aff1b11f2..9ea598dcc132 100644 --- a/arch/x86/xen/smp_pv.c +++ b/arch/x86/xen/smp_pv.c @@ -92,9 +92,7 @@ static void cpu_bringup(void) asmlinkage __visible void cpu_bringup_and_idle(void) { cpu_bringup(); - boot_init_stack_canary(); cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); - prevent_tail_call_optimization(); } void xen_smp_intr_free_pv(unsigned int cpu) |