Inhibit NMI watchdog when Alt-SysRq-T operation is underway

[profile/ivi/kernel-x86-ivi.git] / arch / x86_64 / kernel / traps.c

diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c
index 09d2e8a..74cbeb2 100644 (file)
--- a/arch/x86_64/kernel/traps.c
+++ b/arch/x86_64/kernel/traps.c
@@ -32,6 +32,7 @@
 #include <linux/unwind.h>
 #include <linux/uaccess.h>
 #include <linux/bug.h>
+#include <linux/kdebug.h>
 
 #include <asm/system.h>
 #include <asm/io.h>
@@ -39,7 +40,6 @@
 #include <asm/debugreg.h>
 #include <asm/desc.h>
 #include <asm/i387.h>
-#include <asm/kdebug.h>
 #include <asm/processor.h>
 #include <asm/unwind.h>
 #include <asm/smp.h>
@@ -71,22 +71,6 @@ asmlinkage void alignment_check(void);
 asmlinkage void machine_check(void);
 asmlinkage void spurious_interrupt_bug(void);
 
-ATOMIC_NOTIFIER_HEAD(die_chain);
-EXPORT_SYMBOL(die_chain);
-
-int register_die_notifier(struct notifier_block *nb)
-{
-       vmalloc_sync_all();
-       return atomic_notifier_chain_register(&die_chain, nb);
-}
-EXPORT_SYMBOL(register_die_notifier); /* used modular by kdb */
-
-int unregister_die_notifier(struct notifier_block *nb)
-{
-       return atomic_notifier_chain_unregister(&die_chain, nb);
-}
-EXPORT_SYMBOL(unregister_die_notifier); /* used modular by kdb */
-
 static inline void conditional_sti(struct pt_regs *regs)
 {
        if (regs->eflags & X86_EFLAGS_IF)
@@ -346,6 +330,7 @@ static int print_trace_stack(void *data, char *name)
 
 static void print_trace_address(void *data, unsigned long addr)
 {
+       touch_nmi_watchdog();
        printk_address(addr);
 }
 
@@ -426,8 +411,7 @@ void show_registers(struct pt_regs *regs)
        const int cpu = smp_processor_id();
        struct task_struct *cur = cpu_pda(cpu)->pcurrent;
 
-               rsp = regs->rsp;
-
+       rsp = regs->rsp;
        printk("CPU %d ", cpu);
        __show_regs(regs);
        printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
@@ -438,7 +422,6 @@ void show_registers(struct pt_regs *regs)
         * time of the fault..
         */
        if (in_kernel) {
-
                printk("Stack: ");
                _show_stack(NULL, regs, (unsigned long*)rsp);
 
@@ -483,13 +466,14 @@ static unsigned int die_nest_count;
 
 unsigned __kprobes long oops_begin(void)
 {
-       int cpu = smp_processor_id();
+       int cpu;
        unsigned long flags;
 
        oops_enter();
 
        /* racy, but better than risking deadlock. */
        local_irq_save(flags);
+       cpu = smp_processor_id();
        if (!spin_trylock(&die_lock)) { 
                if (cpu == die_owner) 
                        /* nested oops. should stop eventually */;
@@ -535,6 +519,7 @@ void __kprobes __die(const char * str, struct pt_regs * regs, long err)
        printk("\n");
        notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV);
        show_registers(regs);
+       add_taint(TAINT_DIE);
        /* Executive summary in case the oops scrolled away */
        printk(KERN_ALERT "RIP ");
        printk_address(regs->rip); 
@@ -548,7 +533,7 @@ void die(const char * str, struct pt_regs * regs, long err)
        unsigned long flags = oops_begin();
 
        if (!user_mode(regs))
-               report_bug(regs->rip);
+               report_bug(regs->rip, regs);
 
        __die(str, regs, err);
        oops_end(flags);
@@ -581,10 +566,20 @@ static void __kprobes do_trap(int trapnr, int signr, char *str,
 {
        struct task_struct *tsk = current;
 
-       tsk->thread.error_code = error_code;
-       tsk->thread.trap_no = trapnr;
-
        if (user_mode(regs)) {
+               /*
+                * We want error_code and trap_no set for userspace
+                * faults and kernelspace faults which result in
+                * die(), but not kernelspace faults which are fixed
+                * up.  die() gives the process no chance to handle
+                * the signal and notice the kernel fault information,
+                * so that won't result in polluting the information
+                * about previously queued, but not yet delivered,
+                * faults.  See also do_general_protection below.
+                */
+               tsk->thread.error_code = error_code;
+               tsk->thread.trap_no = trapnr;
+
                if (exception_trace && unhandled_signal(tsk, signr))
                        printk(KERN_INFO
                               "%s[%d] trap %s rip:%lx rsp:%lx error:%lx\n",
@@ -605,8 +600,11 @@ static void __kprobes do_trap(int trapnr, int signr, char *str,
                fixup = search_exception_tables(regs->rip);
                if (fixup)
                        regs->rip = fixup->fixup;
-               else    
+               else {
+                       tsk->thread.error_code = error_code;
+                       tsk->thread.trap_no = trapnr;
                        die(str, regs, error_code);
+               }
                return;
        }
 }
@@ -682,10 +680,10 @@ asmlinkage void __kprobes do_general_protection(struct pt_regs * regs,
 
        conditional_sti(regs);
 
-       tsk->thread.error_code = error_code;
-       tsk->thread.trap_no = 13;
-
        if (user_mode(regs)) {
+               tsk->thread.error_code = error_code;
+               tsk->thread.trap_no = 13;
+
                if (exception_trace && unhandled_signal(tsk, SIGSEGV))
                        printk(KERN_INFO
                       "%s[%d] general protection rip:%lx rsp:%lx error:%lx\n",
@@ -704,6 +702,9 @@ asmlinkage void __kprobes do_general_protection(struct pt_regs * regs,
                        regs->rip = fixup->fixup;
                        return;
                }
+
+               tsk->thread.error_code = error_code;
+               tsk->thread.trap_no = 13;
                if (notify_die(DIE_GPF, "general protection fault", regs,
                                        error_code, 13, SIGSEGV) == NOTIFY_STOP)
                        return;