Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
[cascardo/linux.git] / arch / sh / kernel / traps.c
index f558748..7b40f0f 100644 (file)
@@ -5,7 +5,7 @@
  *  SuperH version: Copyright (C) 1999 Niibe Yutaka
  *                  Copyright (C) 2000 Philipp Rumpf
  *                  Copyright (C) 2000 David Howells
- *                  Copyright (C) 2002 - 2006 Paul Mundt
+ *                  Copyright (C) 2002 - 2007 Paul Mundt
  *
  * This file is subject to the terms and conditions of the GNU General Public
  * License.  See the file "COPYING" in the main directory of this archive
 #include <linux/module.h>
 #include <linux/kallsyms.h>
 #include <linux/io.h>
+#include <linux/bug.h>
+#include <linux/debug_locks.h>
+#include <linux/limits.h>
 #include <asm/system.h>
 #include <asm/uaccess.h>
+#include <asm/kdebug.h>
 
 #ifdef CONFIG_SH_KGDB
 #include <asm/kgdb.h>
-#define CHK_REMOTE_DEBUG(regs)                         \
-{                                              \
+#define CHK_REMOTE_DEBUG(regs)                 \
+{                                              \
        if (kgdb_debug_hook && !user_mode(regs))\
                (*kgdb_debug_hook)(regs);       \
 }
@@ -72,7 +76,21 @@ static void dump_mem(const char *str, unsigned long bottom, unsigned long top)
        }
 }
 
-DEFINE_SPINLOCK(die_lock);
+ATOMIC_NOTIFIER_HEAD(shdie_chain);
+
+int register_die_notifier(struct notifier_block *nb)
+{
+       return atomic_notifier_chain_register(&shdie_chain, nb);
+}
+EXPORT_SYMBOL(register_die_notifier);
+
+int unregister_die_notifier(struct notifier_block *nb)
+{
+       return atomic_notifier_chain_unregister(&shdie_chain, nb);
+}
+EXPORT_SYMBOL(unregister_die_notifier);
+
+static DEFINE_SPINLOCK(die_lock);
 
 void die(const char * str, struct pt_regs * regs, long err)
 {
@@ -93,7 +111,7 @@ void die(const char * str, struct pt_regs * regs, long err)
 
        if (!user_mode(regs) || in_interrupt())
                dump_mem("Stack: ", regs->regs[15], THREAD_SIZE +
-                        (unsigned long)task_stack_page(current));
+                        (unsigned long)task_stack_page(current));
 
        bust_spinlocks(0);
        spin_unlock_irq(&die_lock);
@@ -201,7 +219,7 @@ static int handle_unaligned_ins(u16 instruction, struct pt_regs *regs)
                if (copy_to_user(dst,src,4))
                        goto fetch_fault;
                ret = 0;
-               break;
+               break;
 
        case 2: /* mov.[bwl] to memory, possibly with pre-decrement */
                if (instruction & 4)
@@ -225,7 +243,7 @@ static int handle_unaligned_ins(u16 instruction, struct pt_regs *regs)
                if (copy_from_user(dst,src,4))
                        goto fetch_fault;
                ret = 0;
-               break;
+               break;
 
        case 6: /* mov.[bwl] from memory, possibly with post-increment */
                src = (unsigned char*) *rm;
@@ -233,7 +251,7 @@ static int handle_unaligned_ins(u16 instruction, struct pt_regs *regs)
                        *rm += count;
                dst = (unsigned char*) rn;
                *(unsigned long*)dst = 0;
-               
+
 #ifdef __LITTLE_ENDIAN__
                if (copy_from_user(dst, src, count))
                        goto fetch_fault;
@@ -244,7 +262,7 @@ static int handle_unaligned_ins(u16 instruction, struct pt_regs *regs)
                }
 #else
                dst += 4-count;
-               
+
                if (copy_from_user(dst, src, count))
                        goto fetch_fault;
 
@@ -323,7 +341,8 @@ static inline int handle_unaligned_delayslot(struct pt_regs *regs)
                        return -EFAULT;
 
                /* kernel */
-               die("delay-slot-insn faulting in handle_unaligned_delayslot", regs, 0);
+               die("delay-slot-insn faulting in handle_unaligned_delayslot",
+                   regs, 0);
        }
 
        return handle_unaligned_ins(instruction,regs);
@@ -364,7 +383,8 @@ static int handle_unaligned_access(u16 instruction, struct pt_regs *regs)
        if (user_mode(regs) && handle_unaligned_notify_count>0) {
                handle_unaligned_notify_count--;
 
-               printk("Fixing up unaligned userspace access in \"%s\" pid=%d pc=0x%p ins=0x%04hx\n",
+               printk(KERN_NOTICE "Fixing up unaligned userspace access "
+                      "in \"%s\" pid=%d pc=0x%p ins=0x%04hx\n",
                       current->comm,current->pid,(u16*)regs->pc,instruction);
        }
 
@@ -499,14 +519,23 @@ static int handle_unaligned_access(u16 instruction, struct pt_regs *regs)
 #endif
 
 /*
- * Handle various address error exceptions
+ * Handle various address error exceptions:
+ *  - instruction address error:
+ *       misaligned PC
+ *       PC >= 0x80000000 in user mode
+ *  - data address error (read and write)
+ *       misaligned data access
+ *       access to >= 0x80000000 is user mode
+ * Unfortuntaly we can't distinguish between instruction address error
+ * and data address errors caused by read acceses.
  */
-asmlinkage void do_address_error(struct pt_regs *regs, 
+asmlinkage void do_address_error(struct pt_regs *regs,
                                 unsigned long writeaccess,
                                 unsigned long address)
 {
        unsigned long error_code = 0;
        mm_segment_t oldfs;
+       siginfo_t info;
 #ifndef CONFIG_CPU_SH2A
        u16 instruction;
        int tmp;
@@ -520,22 +549,15 @@ asmlinkage void do_address_error(struct pt_regs *regs,
        oldfs = get_fs();
 
        if (user_mode(regs)) {
+               int si_code = BUS_ADRERR;
+
                local_irq_enable();
-               current->thread.error_code = error_code;
-#ifdef CONFIG_CPU_SH2
-               /*
-                * On the SH-2, we only have a single vector for address
-                * errors, there's no differentiating between a load error
-                * and a store error.
-                */
-               current->thread.trap_no = 9;
-#else
-               current->thread.trap_no = (writeaccess) ? 8 : 7;
-#endif
 
                /* bad PC is not something we can fix */
-               if (regs->pc & 1)
+               if (regs->pc & 1) {
+                       si_code = BUS_ADRALN;
                        goto uspace_segv;
+               }
 
 #ifndef CONFIG_CPU_SH2A
                set_fs(USER_DS);
@@ -554,9 +576,16 @@ asmlinkage void do_address_error(struct pt_regs *regs,
                        return; /* sorted */
 #endif
 
-       uspace_segv:
-               printk(KERN_NOTICE "Killing process \"%s\" due to unaligned access\n", current->comm);
-               force_sig(SIGSEGV, current);
+uspace_segv:
+               printk(KERN_NOTICE "Sending SIGBUS to \"%s\" due to unaligned "
+                      "access (PC %lx PR %lx)\n", current->comm, regs->pc,
+                      regs->pr);
+
+               info.si_signo = SIGBUS;
+               info.si_errno = 0;
+               info.si_code = si_code;
+               info.si_addr = (void *) address;
+               force_sig_info(SIGBUS, &info, current);
        } else {
                if (regs->pc & 1)
                        die("unaligned program counter", regs, error_code);
@@ -574,7 +603,9 @@ asmlinkage void do_address_error(struct pt_regs *regs,
                handle_unaligned_access(instruction, regs);
                set_fs(oldfs);
 #else
-               printk(KERN_NOTICE "Killing process \"%s\" due to unaligned access\n", current->comm);
+               printk(KERN_NOTICE "Killing process \"%s\" due to unaligned "
+                      "access\n", current->comm);
+
                force_sig(SIGSEGV, current);
 #endif
        }
@@ -588,11 +619,11 @@ int is_dsp_inst(struct pt_regs *regs)
 {
        unsigned short inst;
 
-       /* 
+       /*
         * Safe guard if DSP mode is already enabled or we're lacking
         * the DSP altogether.
         */
-       if (!(cpu_data->flags & CPU_HAS_DSP) || (regs->sr & SR_DSP))
+       if (!(current_cpu_data.flags & CPU_HAS_DSP) || (regs->sr & SR_DSP))
                return 0;
 
        get_user(inst, ((unsigned short *) regs->pc));
@@ -612,13 +643,11 @@ int is_dsp_inst(struct pt_regs *regs)
 #ifdef CONFIG_CPU_SH2A
 asmlinkage void do_divide_error(unsigned long r4, unsigned long r5,
                                unsigned long r6, unsigned long r7,
-                               struct pt_regs regs)
+                               struct pt_regs __regs)
 {
+       struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
        siginfo_t info;
 
-       current->thread.trap_no = r4;
-       current->thread.error_code = 0;
-
        switch (r4) {
        case TRAP_DIVZERO_ERROR:
                info.si_code = FPE_INTDIV;
@@ -635,12 +664,13 @@ asmlinkage void do_divide_error(unsigned long r4, unsigned long r5,
 /* arch/sh/kernel/cpu/sh4/fpu.c */
 extern int do_fpu_inst(unsigned short, struct pt_regs *);
 extern asmlinkage void do_fpu_state_restore(unsigned long r4, unsigned long r5,
-               unsigned long r6, unsigned long r7, struct pt_regs regs);
+               unsigned long r6, unsigned long r7, struct pt_regs __regs);
 
 asmlinkage void do_reserved_inst(unsigned long r4, unsigned long r5,
                                unsigned long r6, unsigned long r7,
-                               struct pt_regs regs)
+                               struct pt_regs __regs)
 {
+       struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
        unsigned long error_code;
        struct task_struct *tsk = current;
 
@@ -648,11 +678,11 @@ asmlinkage void do_reserved_inst(unsigned long r4, unsigned long r5,
        unsigned short inst = 0;
        int err;
 
-       get_user(inst, (unsigned short*)regs.pc);
+       get_user(inst, (unsigned short*)regs->pc);
 
-       err = do_fpu_inst(inst, &regs);
+       err = do_fpu_inst(inst, regs);
        if (!err) {
-               regs.pc += 2;
+               regs->pc += 2;
                return;
        }
        /* not a FPU inst. */
@@ -660,9 +690,9 @@ asmlinkage void do_reserved_inst(unsigned long r4, unsigned long r5,
 
 #ifdef CONFIG_SH_DSP
        /* Check if it's a DSP instruction */
-       if (is_dsp_inst(&regs)) {
+       if (is_dsp_inst(regs)) {
                /* Enable DSP mode, and restart instruction. */
-               regs.sr |= SR_DSP;
+               regs->sr |= SR_DSP;
                return;
        }
 #endif
@@ -670,11 +700,9 @@ asmlinkage void do_reserved_inst(unsigned long r4, unsigned long r5,
        lookup_exception_vector(error_code);
 
        local_irq_enable();
-       tsk->thread.error_code = error_code;
-       tsk->thread.trap_no = TRAP_RESERVED_INST;
-       CHK_REMOTE_DEBUG(&regs);
+       CHK_REMOTE_DEBUG(regs);
        force_sig(SIGILL, tsk);
-       die_if_no_fixup("reserved instruction", &regs, error_code);
+       die_if_no_fixup("reserved instruction", regs, error_code);
 }
 
 #ifdef CONFIG_SH_FPU_EMU
@@ -722,17 +750,18 @@ static int emulate_branch(unsigned short inst, struct pt_regs* regs)
 
 asmlinkage void do_illegal_slot_inst(unsigned long r4, unsigned long r5,
                                unsigned long r6, unsigned long r7,
-                               struct pt_regs regs)
+                               struct pt_regs __regs)
 {
+       struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
        unsigned long error_code;
        struct task_struct *tsk = current;
 #ifdef CONFIG_SH_FPU_EMU
        unsigned short inst = 0;
 
-       get_user(inst, (unsigned short *)regs.pc + 1);
-       if (!do_fpu_inst(inst, &regs)) {
-               get_user(inst, (unsigned short *)regs.pc);
-               if (!emulate_branch(inst, &regs))
+       get_user(inst, (unsigned short *)regs->pc + 1);
+       if (!do_fpu_inst(inst, regs)) {
+               get_user(inst, (unsigned short *)regs->pc);
+               if (!emulate_branch(inst, regs))
                        return;
                /* fault in branch.*/
        }
@@ -742,21 +771,20 @@ asmlinkage void do_illegal_slot_inst(unsigned long r4, unsigned long r5,
        lookup_exception_vector(error_code);
 
        local_irq_enable();
-       tsk->thread.error_code = error_code;
-       tsk->thread.trap_no = TRAP_RESERVED_INST;
-       CHK_REMOTE_DEBUG(&regs);
+       CHK_REMOTE_DEBUG(regs);
        force_sig(SIGILL, tsk);
-       die_if_no_fixup("illegal slot instruction", &regs, error_code);
+       die_if_no_fixup("illegal slot instruction", regs, error_code);
 }
 
 asmlinkage void do_exception_error(unsigned long r4, unsigned long r5,
                                   unsigned long r6, unsigned long r7,
-                                  struct pt_regs regs)
+                                  struct pt_regs __regs)
 {
+       struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
        long ex;
 
        lookup_exception_vector(ex);
-       die_if_kernel("exception", &regs, ex);
+       die_if_kernel("exception", regs, ex);
 }
 
 #if defined(CONFIG_SH_STANDARD_BIOS)
@@ -801,7 +829,7 @@ void *set_exception_table_vec(unsigned int vec, void *handler)
 {
        extern void *exception_handling_table[];
        void *old_handler;
-       
+
        old_handler = exception_handling_table[vec];
        exception_handling_table[vec] = handler;
        return old_handler;
@@ -809,7 +837,7 @@ void *set_exception_table_vec(unsigned int vec, void *handler)
 
 extern asmlinkage void address_error_handler(unsigned long r4, unsigned long r5,
                                             unsigned long r6, unsigned long r7,
-                                            struct pt_regs regs);
+                                            struct pt_regs __regs);
 
 void __init trap_init(void)
 {
@@ -837,11 +865,30 @@ void __init trap_init(void)
        set_exception_table_vec(TRAP_DIVZERO_ERROR, do_divide_error);
        set_exception_table_vec(TRAP_DIVOVF_ERROR, do_divide_error);
 #endif
-               
+
        /* Setup VBR for boot cpu */
        per_cpu_trap_init();
 }
 
+#ifdef CONFIG_BUG
+void handle_BUG(struct pt_regs *regs)
+{
+       enum bug_trap_type tt;
+       tt = report_bug(regs->pc);
+       if (tt == BUG_TRAP_TYPE_WARN) {
+               regs->pc += 2;
+               return;
+       }
+
+       die("Kernel BUG", regs, TRAPA_BUG_OPCODE & 0xff);
+}
+
+int is_valid_bugaddr(unsigned long addr)
+{
+       return addr >= PAGE_OFFSET;
+}
+#endif
+
 void show_trace(struct task_struct *tsk, unsigned long *sp,
                struct pt_regs *regs)
 {
@@ -862,6 +909,11 @@ void show_trace(struct task_struct *tsk, unsigned long *sp,
        }
 
        printk("\n");
+
+       if (!tsk)
+               tsk = current;
+
+       debug_show_held_locks(tsk);
 }
 
 void show_stack(struct task_struct *tsk, unsigned long *sp)