5 files changed, 28 insertions, 13 deletions

diff --git a/arch/i386/kernel/alternative.c b/arch/i386/kernel/alternative.c
index 9f4ac8b02de4..bd72d94e713e 100644
--- a/arch/i386/kernel/alternative.c
+++ b/arch/i386/kernel/alternative.c
@@ -445,8 +445,6 @@ void __kprobes text_poke(void *addr, unsigned char *opcode, int len)
 {
         memcpy(addr, opcode, len);
         sync_core();
-        /* Not strictly needed, but can speed CPU recovery up. Ignore cross cacheline
-           case. */
-        if (cpu_has_clflush)
-                asm("clflush (%0) " :: "r" (addr) : "memory");
+        /* Could also do a CLFLUSH here to speed up CPU recovery; but
+           that causes hangs on some VIA CPUs. */
 }
diff --git a/arch/i386/kernel/cpu/intel_cacheinfo.c b/arch/i386/kernel/cpu/intel_cacheinfo.c
index d5a456d27d82..db6c25aa5776 100644
--- a/arch/i386/kernel/cpu/intel_cacheinfo.c
+++ b/arch/i386/kernel/cpu/intel_cacheinfo.c
@@ -515,7 +515,7 @@ static int __cpuinit detect_cache_attributes(unsigned int cpu)
 
         cpuid4_info[cpu] = kzalloc(
             sizeof(struct _cpuid4_info) * num_cache_leaves, GFP_KERNEL);
-        if (unlikely(cpuid4_info[cpu] == NULL))
+        if (cpuid4_info[cpu] == NULL)
                 return -ENOMEM;
 
         oldmask = current->cpus_allowed;
@@ -748,6 +748,8 @@ static void __cpuinit cache_remove_dev(struct sys_device * sys_dev)
         unsigned int cpu = sys_dev->id;
         unsigned long i;
 
+        if (cpuid4_info[cpu] == NULL)
+                return;
         for (i = 0; i < num_cache_leaves; i++) {
                 cache_remove_shared_cpu_map(cpu, i);
                 kobject_unregister(&(INDEX_KOBJECT_PTR(cpu,i)->kobj));
diff --git a/arch/i386/kernel/cpu/perfctr-watchdog.c b/arch/i386/kernel/cpu/perfctr-watchdog.c
index 4be488e73bee..93fecd4b03de 100644
--- a/arch/i386/kernel/cpu/perfctr-watchdog.c
+++ b/arch/i386/kernel/cpu/perfctr-watchdog.c
@@ -263,8 +263,8 @@ static int setup_k7_watchdog(unsigned nmi_hz)
         unsigned int evntsel;
         struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
 
-        perfctr_msr = MSR_K7_PERFCTR0;
-        evntsel_msr = MSR_K7_EVNTSEL0;
+        perfctr_msr = wd_ops->perfctr;
+        evntsel_msr = wd_ops->evntsel;
 
         wrmsrl(perfctr_msr, 0UL);
 
@@ -343,8 +343,8 @@ static int setup_p6_watchdog(unsigned nmi_hz)
         unsigned int evntsel;
         struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
 
-        perfctr_msr = MSR_P6_PERFCTR0;
-        evntsel_msr = MSR_P6_EVNTSEL0;
+        perfctr_msr = wd_ops->perfctr;
+        evntsel_msr = wd_ops->evntsel;
 
         /* KVM doesn't implement this MSR */
         if (wrmsr_safe(perfctr_msr, 0, 0) < 0)
@@ -569,8 +569,8 @@ static int setup_intel_arch_watchdog(unsigned nmi_hz)
             (ebx & ARCH_PERFMON_UNHALTED_CORE_CYCLES_PRESENT))
                 return 0;
 
-        perfctr_msr = MSR_ARCH_PERFMON_PERFCTR1;
-        evntsel_msr = MSR_ARCH_PERFMON_EVENTSEL1;
+        perfctr_msr = wd_ops->perfctr;
+        evntsel_msr = wd_ops->evntsel;
 
         wrmsrl(perfctr_msr, 0UL);
 
@@ -605,6 +605,16 @@ static struct wd_ops intel_arch_wd_ops = {
         .evntsel = MSR_ARCH_PERFMON_EVENTSEL1,
 };
 
+static struct wd_ops coreduo_wd_ops = {
+        .reserve = single_msr_reserve,
+        .unreserve = single_msr_unreserve,
+        .setup = setup_intel_arch_watchdog,
+        .rearm = p6_rearm,
+        .stop = single_msr_stop_watchdog,
+        .perfctr = MSR_ARCH_PERFMON_PERFCTR0,
+        .evntsel = MSR_ARCH_PERFMON_EVENTSEL0,
+};
+
 static void probe_nmi_watchdog(void)
 {
         switch (boot_cpu_data.x86_vendor) {
@@ -615,6 +625,12 @@ static void probe_nmi_watchdog(void)
                 wd_ops = &k7_wd_ops;
                 break;
         case X86_VENDOR_INTEL:
+                /* Work around Core Duo (Yonah) errata AE49 where perfctr1
+                   doesn't have a working enable bit. */
+                if (boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model == 14) {
+                        wd_ops = &coreduo_wd_ops;
+                        break;
+                }
                 if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON)) {
                         wd_ops = &intel_arch_wd_ops;
                         break;
diff --git a/arch/i386/kernel/nmi.c b/arch/i386/kernel/nmi.c
index 8c1c965eb2a8..c7227e2180f8 100644
--- a/arch/i386/kernel/nmi.c
+++ b/arch/i386/kernel/nmi.c
@@ -115,12 +115,12 @@ static int __init check_nmi_watchdog(void)
                         atomic_dec(&nmi_active);
                 }
         }
+        endflag = 1;
         if (!atomic_read(&nmi_active)) {
                 kfree(prev_nmi_count);
                 atomic_set(&nmi_active, -1);
                 return -1;
         }
-        endflag = 1;
         printk("OK.\n");
 
         /* now that we know it works we can reduce NMI frequency to
diff --git a/arch/i386/kernel/ptrace.c b/arch/i386/kernel/ptrace.c
index 0c8f00e69c4d..7c1b92522e95 100644
--- a/arch/i386/kernel/ptrace.c
+++ b/arch/i386/kernel/ptrace.c
@@ -274,7 +274,6 @@ static void clear_singlestep(struct task_struct *child)
 void ptrace_disable(struct task_struct *child)
 { 
         clear_singlestep(child);
-        clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
         clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
 }