ARM: add notify_die() support

Kernel debuggers want to be informed of die() events, so that they
can take some action to allow the problem to be inspected.  Provide
the hook in a similar manner to x86.

Note that we currently don't implement the individual trap hooks.

Acked-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h
index 058e7e9..ca88e6a 100644 (file)
--- a/arch/arm/include/asm/system.h
+++ b/arch/arm/include/asm/system.h
@@ -73,8 +73,7 @@ extern unsigned int mem_fclk_21285;
 
 struct pt_regs;
 
-void die(const char *msg, struct pt_regs *regs, int err)
-               __attribute__((noreturn));
+void die(const char *msg, struct pt_regs *regs, int err);
 
 struct siginfo;
 void arm_notify_die(const char *str, struct pt_regs *regs, struct siginfo *info,

diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 3f361a7..1621e53 100644 (file)
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -12,15 +12,17 @@
  *  'linux/arch/arm/lib/traps.S'.  Mostly a debugging aid, but will probably
  *  kill the offending process.
  */
-#include <linux/module.h>
 #include <linux/signal.h>
-#include <linux/spinlock.h>
 #include <linux/personality.h>
 #include <linux/kallsyms.h>
-#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/uaccess.h>
 #include <linux/hardirq.h>
+#include <linux/kdebug.h>
+#include <linux/module.h>
+#include <linux/kexec.h>
+#include <linux/delay.h>
 #include <linux/init.h>
-#include <linux/uaccess.h>
 
 #include <asm/atomic.h>
 #include <asm/cacheflush.h>
@@ -224,14 +226,21 @@ void show_stack(struct task_struct *tsk, unsigned long *sp)
 #define S_SMP ""
 #endif
 
-static void __die(const char *str, int err, struct thread_info *thread, struct pt_regs *regs)
+static int __die(const char *str, int err, struct thread_info *thread, struct pt_regs *regs)
 {
        struct task_struct *tsk = thread->task;
        static int die_counter;
+       int ret;
 
        printk(KERN_EMERG "Internal error: %s: %x [#%d]" S_PREEMPT S_SMP "\n",
               str, err, ++die_counter);
        sysfs_printk_last_file();
+
+       /* trap and error numbers are mostly meaningless on ARM */
+       ret = notify_die(DIE_OOPS, str, regs, err, tsk->thread.trap_no, SIGSEGV);
+       if (ret == NOTIFY_STOP)
+               return ret;
+
        print_modules();
        __show_regs(regs);
        printk(KERN_EMERG "Process %.*s (pid: %d, stack limit = 0x%p)\n",
@@ -243,6 +252,8 @@ static void __die(const char *str, int err, struct thread_info *thread, struct p
                dump_backtrace(regs, tsk);
                dump_instr(KERN_EMERG, regs);
        }
+
+       return ret;
 }
 
 DEFINE_SPINLOCK(die_lock);
@@ -250,16 +261,21 @@ DEFINE_SPINLOCK(die_lock);
 /*
  * This function is protected against re-entrancy.
  */
-NORET_TYPE void die(const char *str, struct pt_regs *regs, int err)
+void die(const char *str, struct pt_regs *regs, int err)
 {
        struct thread_info *thread = current_thread_info();
+       int ret;
 
        oops_enter();
 
        spin_lock_irq(&die_lock);
        console_verbose();
        bust_spinlocks(1);
-       __die(str, err, thread, regs);
+       ret = __die(str, err, thread, regs);
+
+       if (regs && kexec_should_crash(thread->task))
+               crash_kexec(regs);
+
        bust_spinlocks(0);
        add_taint(TAINT_DIE);
        spin_unlock_irq(&die_lock);
@@ -267,11 +283,10 @@ NORET_TYPE void die(const char *str, struct pt_regs *regs, int err)
 
        if (in_interrupt())
                panic("Fatal exception in interrupt");
-
        if (panic_on_oops)
                panic("Fatal exception");
-
-       do_exit(SIGSEGV);
+       if (ret != NOTIFY_STOP)
+               do_exit(SIGSEGV);
 }
 
 void arm_notify_die(const char *str, struct pt_regs *regs,