3 files changed, 56 insertions, 43 deletions

diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index bb2a8ec440e7..a8f4a70c0742 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -22,6 +22,7 @@ config PARISC
         select GENERIC_SMP_IDLE_THREAD
         select GENERIC_STRNCPY_FROM_USER
         select SYSCTL_ARCH_UNALIGN_ALLOW
+        select SYSCTL_EXCEPTION_TRACE
         select HAVE_MOD_ARCH_SPECIFIC
         select VIRT_TO_BUS
         select MODULES_USE_ELF_RELA
diff --git a/arch/parisc/kernel/traps.c b/arch/parisc/kernel/traps.c
index 1cd1d0c83b6d..47ee620d15d2 100644
--- a/arch/parisc/kernel/traps.c
+++ b/arch/parisc/kernel/traps.c
@@ -25,6 +25,7 @@
 #include <linux/interrupt.h>
 #include <linux/console.h>
 #include <linux/bug.h>
+#include <linux/ratelimit.h>
 
 #include <asm/assembly.h>
 #include <asm/uaccess.h>
@@ -42,9 +43,6 @@
 
 #include "../math-emu/math-emu.h"       /* for handle_fpe() */
 
-#define PRINT_USER_FAULTS /* (turn this on if you want user faults to be */
-                          /*  dumped to the console via printk)          */
-
 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
 DEFINE_SPINLOCK(pa_dbit_lock);
 #endif
@@ -160,6 +158,17 @@ void show_regs(struct pt_regs *regs)
         }
 }
 
+static DEFINE_RATELIMIT_STATE(_hppa_rs,
+        DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST);
+
+#define parisc_printk_ratelimited(critical, regs, fmt, ...)     {             \
+        if ((critical || show_unhandled_signals) && __ratelimit(&_hppa_rs)) { \
+                printk(fmt, ##__VA_ARGS__);                                   \
+                show_regs(regs);                                              \
+        }                                                                     \
+}
+
+
 static void do_show_stack(struct unwind_frame_info *info)
 {
         int i = 1;
@@ -229,12 +238,10 @@ void die_if_kernel(char *str, struct pt_regs *regs, long err)
                 if (err == 0)
                         return; /* STFU */
 
-                printk(KERN_CRIT "%s (pid %d): %s (code %ld) at " RFMT "\n",
+                parisc_printk_ratelimited(1, regs,
+                        KERN_CRIT "%s (pid %d): %s (code %ld) at " RFMT "\n",
                         current->comm, task_pid_nr(current), str, err, regs->iaoq[0]);
-#ifdef PRINT_USER_FAULTS
-                /* XXX for debugging only */
-                show_regs(regs);
-#endif
+
                 return;
         }
 
@@ -321,14 +328,11 @@ static void handle_break(struct pt_regs *regs)
                         (tt == BUG_TRAP_TYPE_NONE) ? 9 : 0);
         }
 
-#ifdef PRINT_USER_FAULTS
-        if (unlikely(iir != GDB_BREAK_INSN)) {
-                printk(KERN_DEBUG "break %d,%d: pid=%d command='%s'\n",
+        if (unlikely(iir != GDB_BREAK_INSN))
+                parisc_printk_ratelimited(0, regs,
+                        KERN_DEBUG "break %d,%d: pid=%d command='%s'\n",
                         iir & 31, (iir>>13) & ((1<<13)-1),
                         task_pid_nr(current), current->comm);
-                show_regs(regs);
-        }
-#endif
 
         /* send standard GDB signal */
         handle_gdb_break(regs, TRAP_BRKPT);
@@ -758,11 +762,9 @@ void notrace handle_interruption(int code, struct pt_regs *regs)
 
         default:
                 if (user_mode(regs)) {
-#ifdef PRINT_USER_FAULTS
-                        printk(KERN_DEBUG "\nhandle_interruption() pid=%d command='%s'\n",
-                            task_pid_nr(current), current->comm);
-                        show_regs(regs);
-#endif
+                        parisc_printk_ratelimited(0, regs, KERN_DEBUG
+                                "handle_interruption() pid=%d command='%s'\n",
+                                task_pid_nr(current), current->comm);
                         /* SIGBUS, for lack of a better one. */
                         si.si_signo = SIGBUS;
                         si.si_code = BUS_OBJERR;
@@ -779,16 +781,10 @@ void notrace handle_interruption(int code, struct pt_regs *regs)
 
         if (user_mode(regs)) {
             if ((fault_space >> SPACEID_SHIFT) != (regs->sr[7] >> SPACEID_SHIFT)) {
-#ifdef PRINT_USER_FAULTS
-                if (fault_space == 0)
-                        printk(KERN_DEBUG "User Fault on Kernel Space ");
-                else
-                        printk(KERN_DEBUG "User Fault (long pointer) (fault %d) ",
-                               code);
-                printk(KERN_CONT "pid=%d command='%s'\n",
-                       task_pid_nr(current), current->comm);
-                show_regs(regs);
-#endif
+                parisc_printk_ratelimited(0, regs, KERN_DEBUG
+                                "User fault %d on space 0x%08lx, pid=%d command='%s'\n",
+                                code, fault_space,
+                                task_pid_nr(current), current->comm);
                 si.si_signo = SIGSEGV;
                 si.si_errno = 0;
                 si.si_code = SEGV_MAPERR;
diff --git a/arch/parisc/mm/fault.c b/arch/parisc/mm/fault.c
index 9d08c71a967e..d72197f0ddb8 100644
--- a/arch/parisc/mm/fault.c
+++ b/arch/parisc/mm/fault.c
@@ -19,10 +19,6 @@
 #include <asm/uaccess.h>
 #include <asm/traps.h>
 
-#define PRINT_USER_FAULTS /* (turn this on if you want user faults to be */
-                         /*  dumped to the console via printk)          */
-
-
 /* Various important other fields */
 #define bit22set(x)             (x & 0x00000200)
 #define bits23_25set(x)         (x & 0x000001c0)
@@ -34,6 +30,8 @@
 
 DEFINE_PER_CPU(struct exception_data, exception_data);
 
+int show_unhandled_signals = 1;
+
 /*
  * parisc_acctyp(unsigned int inst) --
  *    Given a PA-RISC memory access instruction, determine if the
@@ -173,6 +171,32 @@ int fixup_exception(struct pt_regs *regs)
         return 0;
 }
 
+/*
+ * Print out info about fatal segfaults, if the show_unhandled_signals
+ * sysctl is set:
+ */
+static inline void
+show_signal_msg(struct pt_regs *regs, unsigned long code,
+                unsigned long address, struct task_struct *tsk,
+                struct vm_area_struct *vma)
+{
+        if (!unhandled_signal(tsk, SIGSEGV))
+                return;
+
+        if (!printk_ratelimit())
+                return;
+
+        pr_warn("\n");
+        pr_warn("do_page_fault() command='%s' type=%lu address=0x%08lx",
+            tsk->comm, code, address);
+        print_vma_addr(KERN_CONT " in ", regs->iaoq[0]);
+        if (vma)
+                pr_warn(" vm_start = 0x%08lx, vm_end = 0x%08lx\n",
+                                vma->vm_start, vma->vm_end);
+
+        show_regs(regs);
+}
+
 void do_page_fault(struct pt_regs *regs, unsigned long code,
                               unsigned long address)
 {
@@ -270,16 +294,8 @@ bad_area:
         if (user_mode(regs)) {
                 struct siginfo si;
 
-#ifdef PRINT_USER_FAULTS
-                printk(KERN_DEBUG "\n");
-                printk(KERN_DEBUG "do_page_fault() pid=%d command='%s' type=%lu address=0x%08lx\n",
-                    task_pid_nr(tsk), tsk->comm, code, address);
-                if (vma) {
-                        printk(KERN_DEBUG "vm_start = 0x%08lx, vm_end = 0x%08lx\n",
-                                        vma->vm_start, vma->vm_end);
-                }
-                show_regs(regs);
-#endif
+                show_signal_msg(regs, code, address, tsk, vma);
+
                 switch (code) {
                 case 15:        /* Data TLB miss fault/Data page fault */
                         /* send SIGSEGV when outside of vma */