Merge tag 'x86-asm-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

[linux-2.6-microblaze.git] / arch / x86 / kernel / cpu / common.c

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 6bdb69a..a99d003 100644 (file)
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1773,10 +1773,16 @@ void syscall_init(void)
        wrmsrl_safe(MSR_IA32_SYSENTER_EIP, 0ULL);
 #endif
 
-       /* Flags to clear on syscall */
+       /*
+        * Flags to clear on syscall; clear as much as possible
+        * to minimize user space-kernel interference.
+        */
        wrmsrl(MSR_SYSCALL_MASK,
-              X86_EFLAGS_TF|X86_EFLAGS_DF|X86_EFLAGS_IF|
-              X86_EFLAGS_IOPL|X86_EFLAGS_AC|X86_EFLAGS_NT);
+              X86_EFLAGS_CF|X86_EFLAGS_PF|X86_EFLAGS_AF|
+              X86_EFLAGS_ZF|X86_EFLAGS_SF|X86_EFLAGS_TF|
+              X86_EFLAGS_IF|X86_EFLAGS_DF|X86_EFLAGS_OF|
+              X86_EFLAGS_IOPL|X86_EFLAGS_NT|X86_EFLAGS_RF|
+              X86_EFLAGS_AC|X86_EFLAGS_ID);
 }
 
 #else  /* CONFIG_X86_64 */
@@ -1851,8 +1857,8 @@ static inline void setup_getcpu(int cpu)
        unsigned long cpudata = vdso_encode_cpunode(cpu, early_cpu_to_node(cpu));
        struct desc_struct d = { };
 
-       if (boot_cpu_has(X86_FEATURE_RDTSCP))
-               write_rdtscp_aux(cpudata);
+       if (boot_cpu_has(X86_FEATURE_RDTSCP) || boot_cpu_has(X86_FEATURE_RDPID))
+               wrmsr(MSR_TSC_AUX, cpudata, 0);
 
        /* Store CPU and node number in limit. */
        d.limit0 = cpudata;
@@ -1938,13 +1944,12 @@ void cpu_init_exception_handling(void)
 
 /*
  * cpu_init() initializes state that is per-CPU. Some data is already
- * initialized (naturally) in the bootstrap process, such as the GDT
- * and IDT. We reload them nevertheless, this function acts as a
- * 'CPU state barrier', nothing should get across.
+ * initialized (naturally) in the bootstrap process, such as the GDT.  We
+ * reload it nevertheless, this function acts as a 'CPU state barrier',
+ * nothing should get across.
  */
 void cpu_init(void)
 {
-       struct tss_struct *tss = this_cpu_ptr(&cpu_tss_rw);
        struct task_struct *cur = current;
        int cpu = raw_smp_processor_id();
 
@@ -1957,8 +1962,6 @@ void cpu_init(void)
            early_cpu_to_node(cpu) != NUMA_NO_NODE)
                set_numa_node(early_cpu_to_node(cpu));
 #endif
-       setup_getcpu(cpu);
-
        pr_debug("Initializing CPU#%d\n", cpu);
 
        if (IS_ENABLED(CONFIG_X86_64) || cpu_feature_enabled(X86_FEATURE_VME) ||
@@ -1970,7 +1973,6 @@ void cpu_init(void)
         * and set up the GDT descriptor:
         */
        switch_to_new_gdt(cpu);
-       load_current_idt();
 
        if (IS_ENABLED(CONFIG_X86_64)) {
                loadsegment(fs, 0);
@@ -1990,12 +1992,6 @@ void cpu_init(void)
        initialize_tlbstate_and_flush();
        enter_lazy_tlb(&init_mm, cur);
 
-       /* Initialize the TSS. */
-       tss_setup_ist(tss);
-       tss_setup_io_bitmap(tss);
-       set_tss_desc(cpu, &get_cpu_entry_area(cpu)->tss.x86_tss);
-
-       load_TR_desc();
        /*
         * sp0 points to the entry trampoline stack regardless of what task
         * is running.
@@ -2017,6 +2013,18 @@ void cpu_init(void)
        load_fixmap_gdt(cpu);
 }
 
+#ifdef CONFIG_SMP
+void cpu_init_secondary(void)
+{
+       /*
+        * Relies on the BP having set-up the IDT tables, which are loaded
+        * on this CPU in cpu_init_exception_handling().
+        */
+       cpu_init_exception_handling();
+       cpu_init();
+}
+#endif
+
 /*
  * The microcode loader calls this upon late microcode load to recheck features,
  * only when microcode has been updated. Caller holds microcode_mutex and CPU