6 files changed, 31 insertions, 20 deletions

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index f8bddb5b060..3c44b712380 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -988,9 +988,6 @@ static void x86_pmu_start(struct perf_event *event, int flags)
         struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
         int idx = event->hw.idx;
 
-        if (WARN_ON_ONCE(!(event->hw.state & PERF_HES_STOPPED)))
-                return;
-
         if (WARN_ON_ONCE(idx == -1))
                 return;
 
diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
index 73da6b64f5b..d6bd49faa40 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -439,7 +439,6 @@ void intel_pmu_pebs_enable(struct perf_event *event)
         hwc->config &= ~ARCH_PERFMON_EVENTSEL_INT;
 
         cpuc->pebs_enabled |= 1ULL << hwc->idx;
-        WARN_ON_ONCE(cpuc->enabled);
 
         if (x86_pmu.intel_cap.pebs_trap && event->attr.precise_ip > 1)
                 intel_pmu_lbr_enable(event);
diff --git a/arch/x86/kernel/cpu/perf_event_intel_lbr.c b/arch/x86/kernel/cpu/perf_event_intel_lbr.c
index 3fab3de3ce9..47a7e63bfe5 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_lbr.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_lbr.c
@@ -72,8 +72,6 @@ void intel_pmu_lbr_enable(struct perf_event *event)
         if (!x86_pmu.lbr_nr)
                 return;
 
-        WARN_ON_ONCE(cpuc->enabled);
-
         /*
          * Reset the LBR stack if we changed task context to
          * avoid data leaks.
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index 1aae78f775f..4025fe4f928 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -252,7 +252,8 @@ int __kprobes __die(const char *str, struct pt_regs *regs, long err)
         unsigned short ss;
         unsigned long sp;
 #endif
-        printk(KERN_EMERG "%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
+        printk(KERN_DEFAULT
+               "%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
 #ifdef CONFIG_PREEMPT
         printk("PREEMPT ");
 #endif
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
index af7785ff5aa..17107bd6e1f 100644
--- a/arch/x86/kernel/dumpstack_64.c
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -269,11 +269,11 @@ void show_registers(struct pt_regs *regs)
                 unsigned char c;
                 u8 *ip;
 
-                printk(KERN_EMERG "Stack:\n");
+                printk(KERN_DEFAULT "Stack:\n");
                 show_stack_log_lvl(NULL, regs, (unsigned long *)sp,
-                                   0, KERN_EMERG);
+                                   0, KERN_DEFAULT);
 
-                printk(KERN_EMERG "Code: ");
+                printk(KERN_DEFAULT "Code: ");
 
                 ip = (u8 *)regs->ip - code_prologue;
                 if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index 37a458b521a..d840e69a853 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -39,6 +39,14 @@ static int reboot_mode;
 enum reboot_type reboot_type = BOOT_ACPI;
 int reboot_force;
 
+/* This variable is used privately to keep track of whether or not
+ * reboot_type is still set to its default value (i.e., reboot= hasn't
+ * been set on the command line).  This is needed so that we can
+ * suppress DMI scanning for reboot quirks.  Without it, it's
+ * impossible to override a faulty reboot quirk without recompiling.
+ */
+static int reboot_default = 1;
+
 #if defined(CONFIG_X86_32) && defined(CONFIG_SMP)
 static int reboot_cpu = -1;
 #endif
@@ -67,6 +75,12 @@ bool port_cf9_safe = false;
 static int __init reboot_setup(char *str)
 {
         for (;;) {
+                /* Having anything passed on the command line via
+                 * reboot= will cause us to disable DMI checking
+                 * below.
+                 */
+                reboot_default = 0;
+
                 switch (*str) {
                 case 'w':
                         reboot_mode = 0x1234;
@@ -295,14 +309,6 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = {
                         DMI_MATCH(DMI_BOARD_NAME, "P4S800"),
                 },
         },
-        {       /* Handle problems with rebooting on VersaLogic Menlow boards */
-                .callback = set_bios_reboot,
-                .ident = "VersaLogic Menlow based board",
-                .matches = {
-                        DMI_MATCH(DMI_BOARD_VENDOR, "VersaLogic Corporation"),
-                        DMI_MATCH(DMI_BOARD_NAME, "VersaLogic Menlow board"),
-                },
-        },
         { /* Handle reboot issue on Acer Aspire one */
                 .callback = set_kbd_reboot,
                 .ident = "Acer Aspire One A110",
@@ -316,7 +322,12 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = {
 
 static int __init reboot_init(void)
 {
-        dmi_check_system(reboot_dmi_table);
+        /* Only do the DMI check if reboot_type hasn't been overridden
+         * on the command line
+         */
+        if (reboot_default) {
+                dmi_check_system(reboot_dmi_table);
+        }
         return 0;
 }
 core_initcall(reboot_init);
@@ -465,7 +476,12 @@ static struct dmi_system_id __initdata pci_reboot_dmi_table[] = {
 
 static int __init pci_reboot_init(void)
 {
-        dmi_check_system(pci_reboot_dmi_table);
+        /* Only do the DMI check if reboot_type hasn't been overridden
+         * on the command line
+         */
+        if (reboot_default) {
+                dmi_check_system(pci_reboot_dmi_table);
+        }
         return 0;
 }
 core_initcall(pci_reboot_init);