Merge to Fedora kernel-2.6.18-1.2255_FC5-vs2.0.2.2-rc9 patched with stable patch...
[linux-2.6.git] / arch / s390 / kernel / traps.c
index 537700f..bde1d1d 100644 (file)
@@ -14,7 +14,6 @@
  * 'Traps.c' handles hardware traps and faults after we have saved some
  * state in 'asm.s'.
  */
-#include <linux/config.h>
 #include <linux/sched.h>
 #include <linux/kernel.h>
 #include <linux/string.h>
@@ -29,6 +28,7 @@
 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/kallsyms.h>
+#include <linux/reboot.h>
 
 #include <asm/system.h>
 #include <asm/uaccess.h>
@@ -38,6 +38,7 @@
 #include <asm/cpcmd.h>
 #include <asm/s390_ext.h>
 #include <asm/lowcore.h>
+#include <asm/debug.h>
 
 /* Called from entry.S only */
 extern void handle_per_exception(struct pt_regs *regs);
@@ -54,73 +55,105 @@ int sysctl_userprocess_debug = 0;
 #endif
 
 extern pgm_check_handler_t do_protection_exception;
-extern pgm_check_handler_t do_segment_exception;
-extern pgm_check_handler_t do_region_exception;
-extern pgm_check_handler_t do_page_exception;
-extern pgm_check_handler_t do_pseudo_page_fault;
+extern pgm_check_handler_t do_dat_exception;
 #ifdef CONFIG_PFAULT
 extern int pfault_init(void);
 extern void pfault_fini(void);
 extern void pfault_interrupt(struct pt_regs *regs, __u16 error_code);
 static ext_int_info_t ext_int_pfault;
 #endif
-#if defined(CONFIG_NO_IDLE_HZ) || defined(CONFIG_VIRT_TIMER)
 extern pgm_check_handler_t do_monitor_call;
-#endif
 
 #define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
 
-#ifndef CONFIG_ARCH_S390X
-#define RET_ADDR 56
+#ifndef CONFIG_64BIT
 #define FOURLONG "%08lx %08lx %08lx %08lx\n"
 static int kstack_depth_to_print = 12;
-
-#else /* CONFIG_ARCH_S390X */
-#define RET_ADDR 112
+#else /* CONFIG_64BIT */
 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
 static int kstack_depth_to_print = 20;
+#endif /* CONFIG_64BIT */
+
+/*
+ * For show_trace we have tree different stack to consider:
+ *   - the panic stack which is used if the kernel stack has overflown
+ *   - the asynchronous interrupt stack (cpu related)
+ *   - the synchronous kernel stack (process related)
+ * The stack trace can start at any of the three stack and can potentially
+ * touch all of them. The order is: panic stack, async stack, sync stack.
+ */
+static unsigned long
+__show_trace(unsigned long sp, unsigned long low, unsigned long high)
+{
+       struct stack_frame *sf;
+       struct pt_regs *regs;
 
-#endif /* CONFIG_ARCH_S390X */
+       while (1) {
+               sp = sp & PSW_ADDR_INSN;
+               if (sp < low || sp > high - sizeof(*sf))
+                       return sp;
+               sf = (struct stack_frame *) sp;
+               printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
+               print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
+               /* Follow the backchain. */
+               while (1) {
+                       low = sp;
+                       sp = sf->back_chain & PSW_ADDR_INSN;
+                       if (!sp)
+                               break;
+                       if (sp <= low || sp > high - sizeof(*sf))
+                               return sp;
+                       sf = (struct stack_frame *) sp;
+                       printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
+                       print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
+               }
+               /* Zero backchain detected, check for interrupt frame. */
+               sp = (unsigned long) (sf + 1);
+               if (sp <= low || sp > high - sizeof(*regs))
+                       return sp;
+               regs = (struct pt_regs *) sp;
+               printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
+               print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
+               low = sp;
+               sp = regs->gprs[15];
+       }
+}
 
 void show_trace(struct task_struct *task, unsigned long * stack)
 {
-       unsigned long backchain, low_addr, high_addr, ret_addr;
-
-       if (!stack)
-               stack = (task == NULL) ? *stack_pointer : &(task->thread.ksp);
+       register unsigned long __r15 asm ("15");
+       unsigned long sp;
 
+       sp = (unsigned long) stack;
+       if (!sp)
+               sp = task ? task->thread.ksp : __r15;
        printk("Call Trace:\n");
-       low_addr = ((unsigned long) stack) & PSW_ADDR_INSN;
-       high_addr = (low_addr & (-THREAD_SIZE)) + THREAD_SIZE;
-       /* Skip the first frame (biased stack) */
-       backchain = *((unsigned long *) low_addr) & PSW_ADDR_INSN;
-       /* Print up to 8 lines */
-       while  (backchain > low_addr && backchain <= high_addr) {
-               ret_addr = *((unsigned long *) (backchain+RET_ADDR)) & PSW_ADDR_INSN;
-               printk(" [<%016lx>] ", ret_addr);
-               print_symbol("%s\n", ret_addr);
-               low_addr = backchain;
-               backchain = *((unsigned long *) backchain) & PSW_ADDR_INSN;
-       }
+#ifdef CONFIG_CHECK_STACK
+       sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
+                         S390_lowcore.panic_stack);
+#endif
+       sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
+                         S390_lowcore.async_stack);
+       if (task)
+               __show_trace(sp, (unsigned long) task_stack_page(task),
+                            (unsigned long) task_stack_page(task) + THREAD_SIZE);
+       else
+               __show_trace(sp, S390_lowcore.thread_info,
+                            S390_lowcore.thread_info + THREAD_SIZE);
        printk("\n");
 }
 
 void show_stack(struct task_struct *task, unsigned long *sp)
 {
+       register unsigned long * __r15 asm ("15");
        unsigned long *stack;
        int i;
 
-       // debugging aid: "show_stack(NULL);" prints the
-       // back trace for this cpu.
-
-       if (!sp) {
-               if (task)
-                       sp = (unsigned long *) task->thread.ksp;
-               else
-                       sp = *stack_pointer;
-       }
+       if (!sp)
+               stack = task ? (unsigned long *) task->thread.ksp : __r15;
+       else
+               stack = sp;
 
-       stack = sp;
        for (i = 0; i < kstack_depth_to_print; i++) {
                if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
                        break;
@@ -137,7 +170,7 @@ void show_stack(struct task_struct *task, unsigned long *sp)
  */
 void dump_stack(void)
 {
-       show_stack(0, 0);
+       show_stack(NULL, NULL);
 }
 
 EXPORT_SYMBOL(dump_stack);
@@ -204,7 +237,7 @@ char *task_show_regs(struct task_struct *task, char *buffer)
 {
        struct pt_regs *regs;
 
-       regs = __KSTK_PTREGS(task);
+       regs = task_pt_regs(task);
        buffer += sprintf(buffer, "task: %p, ksp: %p\n",
                       task, (void *)task->thread.ksp);
        buffer += sprintf(buffer, "User PSW : %p %p\n",
@@ -237,13 +270,15 @@ char *task_show_regs(struct task_struct *task, char *buffer)
        return buffer;
 }
 
-spinlock_t die_lock = SPIN_LOCK_UNLOCKED;
+DEFINE_SPINLOCK(die_lock);
 
 void die(const char * str, struct pt_regs * regs, long err)
 {
        static int die_counter;
-        console_verbose();
-        spin_lock_irq(&die_lock);
+
+       debug_stop_all();
+       console_verbose();
+       spin_lock_irq(&die_lock);
        bust_spinlocks(1);
        printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
         show_regs(regs);
@@ -256,6 +291,20 @@ void die(const char * str, struct pt_regs * regs, long err)
         do_exit(SIGSEGV);
 }
 
+static void inline
+report_user_fault(long interruption_code, struct pt_regs *regs)
+{
+#if defined(CONFIG_SYSCTL)
+       if (!sysctl_userprocess_debug)
+               return;
+#endif
+#if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG)
+       printk("User process fault: interruption code 0x%lX\n",
+              interruption_code);
+       show_regs(regs);
+#endif
+}
+
 static void inline do_trap(long interruption_code, int signr, char *str,
                            struct pt_regs *regs, siginfo_t *info)
 {
@@ -270,23 +319,8 @@ static void inline do_trap(long interruption_code, int signr, char *str,
                 struct task_struct *tsk = current;
 
                 tsk->thread.trap_no = interruption_code & 0xffff;
-               if (info)
-                       force_sig_info(signr, info, tsk);
-               else
-                       force_sig(signr, tsk);
-#ifndef CONFIG_SYSCTL
-#ifdef CONFIG_PROCESS_DEBUG
-                printk("User process fault: interruption code 0x%lX\n",
-                       interruption_code);
-                show_regs(regs);
-#endif
-#else
-               if (sysctl_userprocess_debug) {
-                       printk("User process fault: interruption code 0x%lX\n",
-                              interruption_code);
-                       show_regs(regs);
-               }
-#endif
+               force_sig_info(signr, info, tsk);
+               report_user_fault(interruption_code, regs);
         } else {
                 const struct exception_table_entry *fixup;
                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
@@ -297,25 +331,26 @@ static void inline do_trap(long interruption_code, int signr, char *str,
         }
 }
 
-static inline void *get_check_address(struct pt_regs *regs)
+static inline void __user *get_check_address(struct pt_regs *regs)
 {
-       return (void *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
+       return (void __user *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
 }
 
-int do_debugger_trap(struct pt_regs *regs)
+void do_single_step(struct pt_regs *regs)
 {
-       if ((regs->psw.mask & PSW_MASK_PSTATE) &&
-           (current->ptrace & PT_PTRACED)) {
-               force_sig(SIGTRAP,current);
-               return 0;
-       }
-       return 1;
+       if ((current->ptrace & PT_PTRACED) != 0)
+               force_sig(SIGTRAP, current);
 }
 
-#define DO_ERROR(signr, str, name) \
-asmlinkage void name(struct pt_regs * regs, long interruption_code) \
-{ \
-       do_trap(interruption_code, signr, str, regs, NULL); \
+asmlinkage void
+default_trap_handler(struct pt_regs * regs, long interruption_code)
+{
+        if (regs->psw.mask & PSW_MASK_PSTATE) {
+               local_irq_enable();
+               do_exit(SIGSEGV);
+               report_user_fault(interruption_code, regs);
+       } else
+               die("Unknown program exception", regs, interruption_code);
 }
 
 #define DO_ERROR_INFO(signr, str, name, sicode, siaddr) \
@@ -325,18 +360,28 @@ asmlinkage void name(struct pt_regs * regs, long interruption_code) \
         info.si_signo = signr; \
         info.si_errno = 0; \
         info.si_code = sicode; \
-        info.si_addr = (void *)siaddr; \
+       info.si_addr = siaddr; \
         do_trap(interruption_code, signr, str, regs, &info); \
 }
 
-DO_ERROR(SIGSEGV, "Unknown program exception", default_trap_handler)
-
-DO_ERROR_INFO(SIGBUS, "addressing exception", addressing_exception,
-             BUS_ADRERR, get_check_address(regs))
+DO_ERROR_INFO(SIGILL, "addressing exception", addressing_exception,
+             ILL_ILLADR, get_check_address(regs))
 DO_ERROR_INFO(SIGILL,  "execute exception", execute_exception,
              ILL_ILLOPN, get_check_address(regs))
 DO_ERROR_INFO(SIGFPE,  "fixpoint divide exception", divide_exception,
              FPE_INTDIV, get_check_address(regs))
+DO_ERROR_INFO(SIGFPE,  "fixpoint overflow exception", overflow_exception,
+             FPE_INTOVF, get_check_address(regs))
+DO_ERROR_INFO(SIGFPE,  "HFP overflow exception", hfp_overflow_exception,
+             FPE_FLTOVF, get_check_address(regs))
+DO_ERROR_INFO(SIGFPE,  "HFP underflow exception", hfp_underflow_exception,
+             FPE_FLTUND, get_check_address(regs))
+DO_ERROR_INFO(SIGFPE,  "HFP significance exception", hfp_significance_exception,
+             FPE_FLTRES, get_check_address(regs))
+DO_ERROR_INFO(SIGFPE,  "HFP divide exception", hfp_divide_exception,
+             FPE_FLTDIV, get_check_address(regs))
+DO_ERROR_INFO(SIGFPE,  "HFP square root exception", hfp_sqrt_exception,
+             FPE_FLTINV, get_check_address(regs))
 DO_ERROR_INFO(SIGILL,  "operand exception", operand_exception,
              ILL_ILLOPN, get_check_address(regs))
 DO_ERROR_INFO(SIGILL,  "privileged operation", privileged_op,
@@ -347,7 +392,7 @@ DO_ERROR_INFO(SIGILL,  "translation exception", translation_exception,
              ILL_ILLOPN, get_check_address(regs))
 
 static inline void
-do_fp_trap(struct pt_regs *regs, void *location,
+do_fp_trap(struct pt_regs *regs, void __user *location,
            int fpc, long interruption_code)
 {
        siginfo_t si;
@@ -377,11 +422,12 @@ do_fp_trap(struct pt_regs *regs, void *location,
 
 asmlinkage void illegal_op(struct pt_regs * regs, long interruption_code)
 {
+       siginfo_t info;
         __u8 opcode[6];
-       __u16 *location;
+       __u16 __user *location;
        int signal = 0;
 
-       location = (__u16 *) get_check_address(regs);
+       location = get_check_address(regs);
 
        /*
         * We got all needed information from the lowcore and can
@@ -390,19 +436,15 @@ asmlinkage void illegal_op(struct pt_regs * regs, long interruption_code)
        if (regs->psw.mask & PSW_MASK_PSTATE)
                local_irq_enable();
 
-       if (regs->psw.mask & PSW_MASK_PSTATE)
-               get_user(*((__u16 *) opcode), (__u16 __user *)location);
-       else
-               *((__u16 *)opcode)=*((__u16 *)location);
-       if (*((__u16 *)opcode)==S390_BREAKPOINT_U16)
-        {
-               if(do_debugger_trap(regs))
-                       signal = SIGILL;
-       }
+       if (regs->psw.mask & PSW_MASK_PSTATE) {
+               get_user(*((__u16 *) opcode), (__u16 __user *) location);
+               if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
+                       if (current->ptrace & PT_PTRACED)
+                               force_sig(SIGTRAP, current);
+                       else
+                               signal = SIGILL;
 #ifdef CONFIG_MATHEMU
-        else if (regs->psw.mask & PSW_MASK_PSTATE)
-       {
-               if (opcode[0] == 0xb3) {
+               } else if (opcode[0] == 0xb3) {
                        get_user(*((__u16 *) (opcode+2)), location+1);
                        signal = math_emu_b3(opcode, regs);
                 } else if (opcode[0] == 0xed) {
@@ -418,18 +460,33 @@ asmlinkage void illegal_op(struct pt_regs * regs, long interruption_code)
                } else if (*((__u16 *) opcode) == 0xb29d) {
                        get_user(*((__u16 *) (opcode+2)), location+1);
                        signal = math_emu_lfpc(opcode, regs);
+#endif
                } else
                        signal = SIGILL;
-        }
-#endif 
-       else
+       } else
                signal = SIGILL;
+
+#ifdef CONFIG_MATHEMU
         if (signal == SIGFPE)
                do_fp_trap(regs, location,
                            current->thread.fp_regs.fpc, interruption_code);
-        else if (signal)
+        else if (signal == SIGSEGV) {
+               info.si_signo = signal;
+               info.si_errno = 0;
+               info.si_code = SEGV_MAPERR;
+               info.si_addr = (void *) location;
                do_trap(interruption_code, signal,
-                       "illegal operation", regs, NULL);
+                       "user address fault", regs, &info);
+       } else
+#endif
+        if (signal) {
+               info.si_signo = signal;
+               info.si_errno = 0;
+               info.si_code = ILL_ILLOPC;
+               info.si_addr = (void __user *) location;
+               do_trap(interruption_code, signal,
+                       "illegal operation", regs, &info);
+       }
 }
 
 
@@ -447,9 +504,9 @@ specification_exception(struct pt_regs * regs, long interruption_code)
         * We got all needed information from the lowcore and can
         * now safely switch on interrupts.
         */
-       if (regs->psw.mask & PSW_MASK_PSTATE)
+        if (regs->psw.mask & PSW_MASK_PSTATE)
                local_irq_enable();
-               
+
         if (regs->psw.mask & PSW_MASK_PSTATE) {
                get_user(*((__u16 *) opcode), location);
                switch (opcode[0]) {
@@ -481,6 +538,7 @@ specification_exception(struct pt_regs * regs, long interruption_code)
                 }
         } else
                signal = SIGILL;
+
         if (signal == SIGFPE)
                do_fp_trap(regs, location,
                            current->thread.fp_regs.fpc, interruption_code);
@@ -501,10 +559,10 @@ DO_ERROR_INFO(SIGILL, "specification exception", specification_exception,
 
 asmlinkage void data_exception(struct pt_regs * regs, long interruption_code)
 {
-       __u16 *location;
+       __u16 __user *location;
        int signal = 0;
 
-       location = (__u16 *) get_check_address(regs);
+       location = get_check_address(regs);
 
        /*
         * We got all needed information from the lowcore and can
@@ -590,7 +648,29 @@ asmlinkage void data_exception(struct pt_regs * regs, long interruption_code)
        }
 }
 
+asmlinkage void space_switch_exception(struct pt_regs * regs, long int_code)
+{
+        siginfo_t info;
+
+       /* Set user psw back to home space mode. */
+       if (regs->psw.mask & PSW_MASK_PSTATE)
+               regs->psw.mask |= PSW_ASC_HOME;
+       /* Send SIGILL. */
+        info.si_signo = SIGILL;
+        info.si_errno = 0;
+        info.si_code = ILL_PRVOPC;
+        info.si_addr = get_check_address(regs);
+        do_trap(int_code, SIGILL, "space switch event", regs, &info);
+}
 
+asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
+{
+       bust_spinlocks(1);
+       printk("Kernel stack overflow.\n");
+       show_regs(regs);
+       bust_spinlocks(0);
+       panic("Corrupt kernel stack, can't continue.");
+}
 
 /* init is done in lowcore.S and head.S */
 
@@ -607,29 +687,34 @@ void __init trap_init(void)
         pgm_check_table[5] = &addressing_exception;
         pgm_check_table[6] = &specification_exception;
         pgm_check_table[7] = &data_exception;
+        pgm_check_table[8] = &overflow_exception;
         pgm_check_table[9] = &divide_exception;
-        pgm_check_table[0x10] = &do_segment_exception;
-        pgm_check_table[0x11] = &do_page_exception;
+        pgm_check_table[0x0A] = &overflow_exception;
+        pgm_check_table[0x0B] = &divide_exception;
+        pgm_check_table[0x0C] = &hfp_overflow_exception;
+        pgm_check_table[0x0D] = &hfp_underflow_exception;
+        pgm_check_table[0x0E] = &hfp_significance_exception;
+        pgm_check_table[0x0F] = &hfp_divide_exception;
+        pgm_check_table[0x10] = &do_dat_exception;
+        pgm_check_table[0x11] = &do_dat_exception;
         pgm_check_table[0x12] = &translation_exception;
         pgm_check_table[0x13] = &special_op_exception;
-#ifndef CONFIG_ARCH_S390X
-       pgm_check_table[0x14] = &do_pseudo_page_fault;
-#else /* CONFIG_ARCH_S390X */
-        pgm_check_table[0x38] = &addressing_exception;
-        pgm_check_table[0x3B] = &do_region_exception;
-#endif /* CONFIG_ARCH_S390X */
+#ifdef CONFIG_64BIT
+        pgm_check_table[0x38] = &do_dat_exception;
+       pgm_check_table[0x39] = &do_dat_exception;
+       pgm_check_table[0x3A] = &do_dat_exception;
+        pgm_check_table[0x3B] = &do_dat_exception;
+#endif /* CONFIG_64BIT */
         pgm_check_table[0x15] = &operand_exception;
-        pgm_check_table[0x1C] = &privileged_op;
-#if defined(CONFIG_VIRT_TIMER) || defined(CONFIG_NO_IDLE_HZ)
+        pgm_check_table[0x1C] = &space_switch_exception;
+        pgm_check_table[0x1D] = &hfp_sqrt_exception;
        pgm_check_table[0x40] = &do_monitor_call;
-#endif
+
        if (MACHINE_IS_VM) {
+#ifdef CONFIG_PFAULT
                /*
-                * First try to get pfault pseudo page faults going.
-                * If this isn't available turn on pagex page faults.
+                * Try to get pfault pseudo page faults going.
                 */
-#ifdef CONFIG_PFAULT
-               /* request the 0x2603 external interrupt */
                if (register_early_external_interrupt(0x2603, pfault_interrupt,
                                                      &ext_int_pfault) != 0)
                        panic("Couldn't request external interrupt 0x2603");
@@ -640,9 +725,6 @@ void __init trap_init(void)
                /* Tough luck, no pfault. */
                unregister_early_external_interrupt(0x2603, pfault_interrupt,
                                                    &ext_int_pfault);
-#endif
-#ifndef CONFIG_ARCH_S390X
-               cpcmd("SET PAGEX ON", NULL, 0);
 #endif
        }
 }