Merge branch 'parisc-4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux

Pull more parisc updates from Helge Deller:

 - fix boot failure of 64-bit kernel. It got broken by the unwind
   optimization commit in merge window.

 - fix 64-bit userspace support (static 64-bit applications only, e.g.
   we don't yet have 64-bit userspace support in glibc).

 - consolidate unwind initialization code.

 - add machine model description to stack trace.

* 'parisc-4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Add hardware description to stack traces
  parisc: Fix boot failure of 64-bit kernel
  parisc: Consolidate unwind initialization calls
  parisc: Update comments in syscall.S regarding wide userland
  parisc: Fix ptraced 64-bit applications to call 64-bit syscalls
  parisc: Restore possibility to execute 64-bit applications

12 files changed, 113 insertions, 137 deletions

diff --git a/arch/parisc/include/asm/elf.h b/arch/parisc/include/asm/elf.h
index f019d3ec0c1c..d00973aab7f1 100644
--- a/arch/parisc/include/asm/elf.h
+++ b/arch/parisc/include/asm/elf.h
@@ -235,6 +235,7 @@ typedef unsigned long elf_greg_t;
 #define SET_PERSONALITY(ex) \
 ({      \
         set_personality((current->personality & ~PER_MASK) | PER_LINUX); \
+        clear_thread_flag(TIF_32BIT); \
         current->thread.map_base = DEFAULT_MAP_BASE; \
         current->thread.task_size = DEFAULT_TASK_SIZE; \
  })
@@ -243,9 +244,11 @@ typedef unsigned long elf_greg_t;
 
 #define COMPAT_SET_PERSONALITY(ex) \
 ({      \
-        set_thread_flag(TIF_32BIT); \
-        current->thread.map_base = DEFAULT_MAP_BASE32; \
-        current->thread.task_size = DEFAULT_TASK_SIZE32; \
+        if ((ex).e_ident[EI_CLASS] == ELFCLASS32) { \
+                set_thread_flag(TIF_32BIT); \
+                current->thread.map_base = DEFAULT_MAP_BASE32; \
+                current->thread.task_size = DEFAULT_TASK_SIZE32; \
+        } else clear_thread_flag(TIF_32BIT); \
  })
 
 /*
diff --git a/arch/parisc/include/asm/linkage.h b/arch/parisc/include/asm/linkage.h
index 49f6f3d772cc..cd6fe4febead 100644
--- a/arch/parisc/include/asm/linkage.h
+++ b/arch/parisc/include/asm/linkage.h
@@ -22,15 +22,6 @@
 name:           ASM_NL\
         .export name
 
-#ifdef CONFIG_64BIT
-#define ENDPROC(name) \
-        END(name)
-#else
-#define ENDPROC(name) \
-        .type name, @function !\
-        END(name)
-#endif
-
 #define ENTRY_CFI(name, ...) \
         ENTRY(name)     ASM_NL\
         .proc           ASM_NL\
diff --git a/arch/parisc/include/asm/processor.h b/arch/parisc/include/asm/processor.h
index 2dbe5580a1a4..2bd5e695bdad 100644
--- a/arch/parisc/include/asm/processor.h
+++ b/arch/parisc/include/asm/processor.h
@@ -256,11 +256,7 @@ on downward growing arches, it looks like this:
  * it in here from the current->personality
  */
 
-#ifdef CONFIG_64BIT
-#define USER_WIDE_MODE  (!test_thread_flag(TIF_32BIT))
-#else
-#define USER_WIDE_MODE  0
-#endif
+#define USER_WIDE_MODE  (!is_32bit_task())
 
 #define start_thread(regs, new_pc, new_sp) do {         \
         elf_addr_t *sp = (elf_addr_t *)new_sp;          \
diff --git a/arch/parisc/include/asm/traps.h b/arch/parisc/include/asm/traps.h
index e00013248907..8ecc1f0c0483 100644
--- a/arch/parisc/include/asm/traps.h
+++ b/arch/parisc/include/asm/traps.h
@@ -2,7 +2,9 @@
 #ifndef __ASM_TRAPS_H
 #define __ASM_TRAPS_H
 
-#ifdef __KERNEL__
+#define PARISC_ITLB_TRAP        6 /* defined by architecture. Do not change. */
+
+#if !defined(__ASSEMBLY__)
 struct pt_regs;
 
 /* traps.c */
diff --git a/arch/parisc/include/asm/unwind.h b/arch/parisc/include/asm/unwind.h
index f133b7efbebb..9547e5261a8b 100644
--- a/arch/parisc/include/asm/unwind.h
+++ b/arch/parisc/include/asm/unwind.h
@@ -73,8 +73,10 @@ unwind_table_remove(struct unwind_table *table);
 
 void unwind_frame_init(struct unwind_frame_info *info, struct task_struct *t, 
                        struct pt_regs *regs);
-void unwind_frame_init_from_blocked_task(struct unwind_frame_info *info, struct task_struct *t);
-void unwind_frame_init_running(struct unwind_frame_info *info, struct pt_regs *regs);
+void unwind_frame_init_from_blocked_task(struct unwind_frame_info *info,
+                        struct task_struct *t);
+void unwind_frame_init_task(struct unwind_frame_info *info,
+                        struct task_struct *task, struct pt_regs *regs);
 int unwind_once(struct unwind_frame_info *info);
 int unwind_to_user(struct unwind_frame_info *info);
 
diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S
index c7508f5717fb..242c5ab65611 100644
--- a/arch/parisc/kernel/entry.S
+++ b/arch/parisc/kernel/entry.S
@@ -36,6 +36,7 @@
 #include <asm/signal.h>
 #include <asm/unistd.h>
 #include <asm/ldcw.h>
+#include <asm/traps.h>
 #include <asm/thread_info.h>
 
 #include <linux/linkage.h>
@@ -692,7 +693,7 @@ ENTRY(fault_vector_20)
         def              3
         extint           4
         def              5
-        itlb_20          6
+        itlb_20          PARISC_ITLB_TRAP
         def              7
         def              8
         def              9
@@ -735,7 +736,7 @@ ENTRY(fault_vector_11)
         def              3
         extint           4
         def              5
-        itlb_11          6
+        itlb_11          PARISC_ITLB_TRAP
         def              7
         def              8
         def              9
@@ -776,7 +777,7 @@ END(fault_vector_11)
          * copy_thread moved args into task save area.
          */
 
-ENTRY_CFI(ret_from_kernel_thread)
+ENTRY(ret_from_kernel_thread)
         /* Call schedule_tail first though */
         BL      schedule_tail, %r2
         nop
@@ -791,7 +792,7 @@ ENTRY_CFI(ret_from_kernel_thread)
         copy    %r31, %r2
         b       finish_child_return
         nop
-ENDPROC_CFI(ret_from_kernel_thread)
+END(ret_from_kernel_thread)
 
 
         /*
@@ -815,9 +816,8 @@ ENTRY_CFI(_switch_to)
         LDREG   TASK_THREAD_INFO(%r25), %r25
         bv      %r0(%r2)
         mtctl   %r25,%cr30
-ENDPROC_CFI(_switch_to)
 
-ENTRY_CFI(_switch_to_ret)
+ENTRY(_switch_to_ret)
         mtctl   %r0, %cr0               /* Needed for single stepping */
         callee_rest
         callee_rest_float
@@ -825,7 +825,7 @@ ENTRY_CFI(_switch_to_ret)
         LDREG   -RP_OFFSET(%r30), %r2
         bv      %r0(%r2)
         copy    %r26, %r28
-ENDPROC_CFI(_switch_to_ret)
+ENDPROC_CFI(_switch_to)
 
         /*
          * Common rfi return path for interruptions, kernel execve, and
@@ -886,14 +886,12 @@ ENTRY_CFI(syscall_exit_rfi)
         STREG   %r19,PT_SR5(%r16)
         STREG   %r19,PT_SR6(%r16)
         STREG   %r19,PT_SR7(%r16)
-ENDPROC_CFI(syscall_exit_rfi)
 
-ENTRY_CFI(intr_return)
+ENTRY(intr_return)
         /* check for reschedule */
         mfctl   %cr30,%r1
         LDREG   TI_FLAGS(%r1),%r19      /* sched.h: TIF_NEED_RESCHED */
         bb,<,n  %r19,31-TIF_NEED_RESCHED,intr_do_resched /* forward */
-ENDPROC_CFI(intr_return)
 
         .import do_notify_resume,code
 intr_check_sig:
@@ -1049,6 +1047,7 @@ intr_extint:
 
         b       do_cpu_irq_mask
         ldo     R%intr_return(%r2), %r2 /* return to intr_return, not here */
+ENDPROC_CFI(syscall_exit_rfi)
 
 
         /* Generic interruptions (illegal insn, unaligned, page fault, etc) */
@@ -1068,21 +1067,12 @@ ENTRY_CFI(intr_save)		/* for os_hpmc */
         save_specials   %r29
 
         /* If this trap is a itlb miss, skip saving/adjusting isr/ior */
-
-        /*
-         * FIXME: 1) Use a #define for the hardwired "6" below (and in
-         *           traps.c.
-         *        2) Once we start executing code above 4 Gb, we need
-         *           to adjust iasq/iaoq here in the same way we
-         *           adjust isr/ior below.
-         */
-
-        cmpib,COND(=),n        6,%r26,skip_save_ior
+        cmpib,COND(=),n        PARISC_ITLB_TRAP,%r26,skip_save_ior
 
 
-        mfctl           %cr20, %r16 /* isr */
+        mfctl           %isr, %r16
         nop             /* serialize mfctl on PA 2.0 to avoid 4 cycle penalty */
-        mfctl           %cr21, %r17 /* ior */
+        mfctl           %ior, %r17
 
 
 #ifdef CONFIG_64BIT
@@ -1094,22 +1084,34 @@ ENTRY_CFI(intr_save)		/* for os_hpmc */
         extrd,u,*<>     %r8,PSW_W_BIT,1,%r0
         depdi           0,1,2,%r17
 
-        /*
-         * FIXME: This code has hardwired assumptions about the split
-         *        between space bits and offset bits. This will change
-         *        when we allow alternate page sizes.
-         */
-
-        /* adjust isr/ior. */
-        extrd,u         %r16,63,SPACEID_SHIFT,%r1       /* get high bits from isr for ior */
-        depd            %r1,31,SPACEID_SHIFT,%r17       /* deposit them into ior */
-        depdi           0,63,SPACEID_SHIFT,%r16         /* clear them from isr */
+        /* adjust isr/ior: get high bits from isr and deposit in ior */
+        space_adjust    %r16,%r17,%r1
 #endif
         STREG           %r16, PT_ISR(%r29)
         STREG           %r17, PT_IOR(%r29)
 
+#if 0 && defined(CONFIG_64BIT)
+        /* Revisit when we have 64-bit code above 4Gb */
+        b,n             intr_save2
 
 skip_save_ior:
+        /* We have a itlb miss, and when executing code above 4 Gb on ILP64, we
+         * need to adjust iasq/iaoq here in the same way we adjusted isr/ior
+         * above.
+         */
+        extrd,u,*       %r8,PSW_W_BIT,1,%r1
+        cmpib,COND(=),n 1,%r1,intr_save2
+        LDREG           PT_IASQ0(%r29), %r16
+        LDREG           PT_IAOQ0(%r29), %r17
+        /* adjust iasq/iaoq */
+        space_adjust    %r16,%r17,%r1
+        STREG           %r16, PT_IASQ0(%r29)
+        STREG           %r17, PT_IAOQ0(%r29)
+#else
+skip_save_ior:
+#endif
+
+intr_save2:
         virt_map
         save_general    %r29
 
@@ -1747,7 +1749,7 @@ fork_like fork
 fork_like vfork
 
         /* Set the return value for the child */
-ENTRY_CFI(child_return)
+ENTRY(child_return)
         BL      schedule_tail, %r2
         nop
 finish_child_return:
@@ -1759,7 +1761,7 @@ finish_child_return:
         reg_restore %r1
         b       syscall_exit
         copy    %r0,%r28
-ENDPROC_CFI(child_return)
+END(child_return)
 
 ENTRY_CFI(sys_rt_sigreturn_wrapper)
         LDREG   TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r26
@@ -1791,7 +1793,7 @@ ENTRY_CFI(sys_rt_sigreturn_wrapper)
         LDREG   PT_GR28(%r1),%r28  /* reload original r28 for syscall_exit */
 ENDPROC_CFI(sys_rt_sigreturn_wrapper)
 
-ENTRY_CFI(syscall_exit)
+ENTRY(syscall_exit)
         /* NOTE: Not all syscalls exit this way.  rt_sigreturn will exit
          * via syscall_exit_rfi if the signal was received while the process
          * was running.
@@ -1990,15 +1992,13 @@ syscall_do_resched:
 #else
         nop
 #endif
-ENDPROC_CFI(syscall_exit)
+END(syscall_exit)
 
 
 #ifdef CONFIG_FUNCTION_TRACER
 
         .import ftrace_function_trampoline,code
         .align L1_CACHE_BYTES
-        .globl mcount
-        .type  mcount, @function
 ENTRY_CFI(mcount, caller)
 _mcount:
         .export _mcount,data
@@ -2027,8 +2027,6 @@ ENDPROC_CFI(mcount)
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
         .align 8
-        .globl return_to_handler
-        .type  return_to_handler, @function
 ENTRY_CFI(return_to_handler, caller,frame=FRAME_SIZE)
         .export parisc_return_to_handler,data
 parisc_return_to_handler:
@@ -2078,6 +2076,7 @@ ENDPROC_CFI(return_to_handler)
 /* void call_on_stack(unsigned long param1, void *func,
                       unsigned long new_stack) */
 ENTRY_CFI(call_on_stack, FRAME=2*FRAME_SIZE,CALLS,SAVE_RP,SAVE_SP)
+ENTRY(_call_on_stack)
         copy    %sp, %r1
 
         /* Regarding the HPPA calling conventions for function pointers,
diff --git a/arch/parisc/kernel/processor.c b/arch/parisc/kernel/processor.c
index 45cc65902fce..82bd0d0927ce 100644
--- a/arch/parisc/kernel/processor.c
+++ b/arch/parisc/kernel/processor.c
@@ -288,6 +288,8 @@ void __init collect_boot_cpu_data(void)
                 printk(KERN_INFO "model %s\n",
                         boot_cpu_data.pdc.sys_model_name);
 
+        dump_stack_set_arch_desc("%s", boot_cpu_data.pdc.sys_model_name);
+
         boot_cpu_data.hversion =  boot_cpu_data.pdc.model.hversion;
         boot_cpu_data.sversion =  boot_cpu_data.pdc.model.sversion;
 
diff --git a/arch/parisc/kernel/stacktrace.c b/arch/parisc/kernel/stacktrace.c
index 2fe914c5f533..ec5835e83a7a 100644
--- a/arch/parisc/kernel/stacktrace.c
+++ b/arch/parisc/kernel/stacktrace.c
@@ -16,20 +16,7 @@ static void dump_trace(struct task_struct *task, struct stack_trace *trace)
 {
         struct unwind_frame_info info;
 
-        /* initialize unwind info */
-        if (task == current) {
-                unsigned long sp;
-                struct pt_regs r;
-HERE:
-                asm volatile ("copy %%r30, %0" : "=r"(sp));
-                memset(&r, 0, sizeof(struct pt_regs));
-                r.iaoq[0] = (unsigned long)&&HERE;
-                r.gr[2] = (unsigned long)__builtin_return_address(0);
-                r.gr[30] = sp;
-                unwind_frame_init(&info, task, &r);
-        } else {
-                unwind_frame_init_from_blocked_task(&info, task);
-        }
+        unwind_frame_init_task(&info, task, NULL);
 
         /* unwind stack and save entries in stack_trace struct */
         trace->nr_entries = 0;
diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c
index 43b308cfdf53..376ea0d1b275 100644
--- a/arch/parisc/kernel/sys_parisc.c
+++ b/arch/parisc/kernel/sys_parisc.c
@@ -156,11 +156,6 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
         int do_color_align, last_mmap;
         struct vm_unmapped_area_info info;
 
-#ifdef CONFIG_64BIT
-        /* This should only ever run for 32-bit processes.  */
-        BUG_ON(!test_thread_flag(TIF_32BIT));
-#endif
-
         /* requested length too big for entire address space */
         if (len > TASK_SIZE)
                 return -ENOMEM;
diff --git a/arch/parisc/kernel/syscall.S b/arch/parisc/kernel/syscall.S
index 5f7e57fcaeef..f453997a7b8f 100644
--- a/arch/parisc/kernel/syscall.S
+++ b/arch/parisc/kernel/syscall.S
@@ -108,12 +108,8 @@ linux_gateway_entry:
         mtsp    %r0,%sr6                        /* get kernel space into sr6 */
 
 #ifdef CONFIG_64BIT
-        /* for now we can *always* set the W bit on entry to the syscall
-         * since we don't support wide userland processes.  We could
-         * also save the current SM other than in r0 and restore it on
-         * exit from the syscall, and also use that value to know
-         * whether to do narrow or wide syscalls. -PB
-         */
+        /* Store W bit on entry to the syscall in case it's a wide userland
+         * process. */
         ssm     PSW_SM_W, %r1
         extrd,u %r1,PSW_W_BIT,1,%r1
         /* sp must be aligned on 4, so deposit the W bit setting into
@@ -227,8 +223,7 @@ linux_gateway_entry:
         or,=    %r2,%r2,%r2
         ldo     R%sys_call_table64(%r1), %r19
 #else
-        ldil    L%sys_call_table, %r1
-        ldo     R%sys_call_table(%r1), %r19
+        load32  sys_call_table, %r19
 #endif  
         comiclr,>>      __NR_Linux_syscalls, %r20, %r0
         b,n     .Lsyscall_nosys
@@ -331,8 +326,6 @@ tracesys_next:
          *  task->thread.regs.gr[20] above.
          */
         copy    %ret0,%r20
-        ldil    L%sys_call_table,%r1
-        ldo     R%sys_call_table(%r1), %r19
 
         ldo     -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1      /* get task ptr */
         LDREG   TI_TASK(%r1), %r1
@@ -354,6 +347,23 @@ tracesys_next:
         comiclr,>>      __NR_Linux_syscalls, %r20, %r0
         b,n     .Ltracesys_nosys
 
+        /* Note!  We cannot use the syscall table that is mapped
+        nearby since the gateway page is mapped execute-only. */
+
+#ifdef CONFIG_64BIT
+        LDREG   TASK_PT_GR30(%r1), %r19         /* get users sp back */
+        extrd,u %r19,63,1,%r2                   /* W hidden in bottom bit */
+
+        ldil    L%sys_call_table, %r1
+        or,=    %r2,%r2,%r2
+        addil   L%(sys_call_table64-sys_call_table), %r1
+        ldo     R%sys_call_table(%r1), %r19
+        or,=    %r2,%r2,%r2
+        ldo     R%sys_call_table64(%r1), %r19
+#else
+        load32  sys_call_table, %r19
+#endif
+
         LDREGX  %r20(%r19), %r19
 
         /* If this is a sys_rt_sigreturn call, and the signal was received
@@ -464,16 +474,13 @@ tracesys_sigexit:
 lws_start:
 
 #ifdef CONFIG_64BIT
-        /* FIXME: If we are a 64-bit kernel just
-         *        turn this on unconditionally.
-         */
         ssm     PSW_SM_W, %r1
         extrd,u %r1,PSW_W_BIT,1,%r1
         /* sp must be aligned on 4, so deposit the W bit setting into
          * the bottom of sp temporarily */
         or,ev   %r1,%r30,%r30
 
-        /* Clip LWS number to a 32-bit value always */
+        /* Clip LWS number to a 32-bit value for 32-bit processes */
         depdi   0, 31, 32, %r20
 #endif  
 
diff --git a/arch/parisc/kernel/traps.c b/arch/parisc/kernel/traps.c
index 318815212518..68f10f87073d 100644
--- a/arch/parisc/kernel/traps.c
+++ b/arch/parisc/kernel/traps.c
@@ -45,7 +45,7 @@
 
 #include "../math-emu/math-emu.h"       /* for handle_fpe() */
 
-static void parisc_show_stack(struct task_struct *task, unsigned long *sp,
+static void parisc_show_stack(struct task_struct *task,
         struct pt_regs *regs);
 
 static int printbinary(char *buf, unsigned long x, int nbits)
@@ -152,7 +152,7 @@ void show_regs(struct pt_regs *regs)
                 printk("%s IAOQ[1]: %pS\n", level, (void *) regs->iaoq[1]);
                 printk("%s RP(r2): %pS\n", level, (void *) regs->gr[2]);
 
-                parisc_show_stack(current, NULL, regs);
+                parisc_show_stack(current, regs);
         }
 }
 
@@ -185,44 +185,19 @@ static void do_show_stack(struct unwind_frame_info *info)
         printk(KERN_CRIT "\n");
 }
 
-static void parisc_show_stack(struct task_struct *task, unsigned long *sp,
+static void parisc_show_stack(struct task_struct *task,
         struct pt_regs *regs)
 {
         struct unwind_frame_info info;
-        struct task_struct *t;
 
-        t = task ? task : current;
-        if (regs) {
-                unwind_frame_init(&info, t, regs);
-                goto show_stack;
-        }
-
-        if (t == current) {
-                unsigned long sp;
-
-HERE:
-                asm volatile ("copy %%r30, %0" : "=r"(sp));
-                {
-                        struct pt_regs r;
-
-                        memset(&r, 0, sizeof(struct pt_regs));
-                        r.iaoq[0] = (unsigned long)&&HERE;
-                        r.gr[2] = (unsigned long)__builtin_return_address(0);
-                        r.gr[30] = sp;
-
-                        unwind_frame_init(&info, current, &r);
-                }
-        } else {
-                unwind_frame_init_from_blocked_task(&info, t);
-        }
+        unwind_frame_init_task(&info, task, regs);
 
-show_stack:
         do_show_stack(&info);
 }
 
 void show_stack(struct task_struct *t, unsigned long *sp)
 {
-        return parisc_show_stack(t, sp, NULL);
+        parisc_show_stack(t, NULL);
 }
 
 int is_valid_bugaddr(unsigned long iaoq)
@@ -557,7 +532,7 @@ void notrace handle_interruption(int code, struct pt_regs *regs)
                 cpu_lpmc(5, regs);
                 return;
 
-        case  6:
+        case  PARISC_ITLB_TRAP:
                 /* Instruction TLB miss fault/Instruction page fault */
                 fault_address = regs->iaoq[0];
                 fault_space   = regs->iasq[0];
diff --git a/arch/parisc/kernel/unwind.c b/arch/parisc/kernel/unwind.c
index 5cdf13069dd9..f329b466e68f 100644
--- a/arch/parisc/kernel/unwind.c
+++ b/arch/parisc/kernel/unwind.c
@@ -209,6 +209,8 @@ static int unwind_special(struct unwind_frame_info *info, unsigned long pc, int
          * We have to use void * instead of a function pointer, because
          * function pointers aren't a pointer to the function on 64-bit.
          * Make them const so the compiler knows they live in .text
+         * Note: We could use dereference_kernel_function_descriptor()
+         * instead but we want to keep it simple here.
          */
         extern void * const handle_interruption;
         extern void * const ret_from_kernel_thread;
@@ -216,7 +218,7 @@ static int unwind_special(struct unwind_frame_info *info, unsigned long pc, int
         extern void * const intr_return;
         extern void * const _switch_to_ret;
 #ifdef CONFIG_IRQSTACKS
-        extern void * const call_on_stack;
+        extern void * const _call_on_stack;
 #endif /* CONFIG_IRQSTACKS */
 
         if (pc == (unsigned long) &handle_interruption) {
@@ -251,7 +253,7 @@ static int unwind_special(struct unwind_frame_info *info, unsigned long pc, int
         }
 
 #ifdef CONFIG_IRQSTACKS
-        if (pc == (unsigned long) &call_on_stack) {
+        if (pc == (unsigned long) &_call_on_stack) {
                 info->prev_sp = *(unsigned long *)(info->sp - FRAME_SIZE - REG_SZ);
                 info->prev_ip = *(unsigned long *)(info->sp - FRAME_SIZE - RP_OFFSET);
                 return 1;
@@ -403,9 +405,31 @@ void unwind_frame_init_from_blocked_task(struct unwind_frame_info *info, struct
         kfree(r2);
 }
 
-void unwind_frame_init_running(struct unwind_frame_info *info, struct pt_regs *regs)
+#define get_parisc_stackpointer() ({ \
+        unsigned long sp; \
+        __asm__("copy %%r30, %0" : "=r"(sp)); \
+        (sp); \
+})
+
+void unwind_frame_init_task(struct unwind_frame_info *info,
+        struct task_struct *task, struct pt_regs *regs)
 {
-        unwind_frame_init(info, current, regs);
+        task = task ? task : current;
+
+        if (task == current) {
+                struct pt_regs r;
+
+                if (!regs) {
+                        memset(&r, 0, sizeof(r));
+                        r.iaoq[0] =  _THIS_IP_;
+                        r.gr[2] = _RET_IP_;
+                        r.gr[30] = get_parisc_stackpointer();
+                        regs = &r;
+                }
+                unwind_frame_init(info, task, &r);
+        } else {
+                unwind_frame_init_from_blocked_task(info, task);
+        }
 }
 
 int unwind_once(struct unwind_frame_info *next_frame)
@@ -442,19 +466,12 @@ int unwind_to_user(struct unwind_frame_info *info)
 unsigned long return_address(unsigned int level)
 {
         struct unwind_frame_info info;
-        struct pt_regs r;
-        unsigned long sp;
 
         /* initialize unwind info */
-        asm volatile ("copy %%r30, %0" : "=r"(sp));
-        memset(&r, 0, sizeof(struct pt_regs));
-        r.iaoq[0] = _THIS_IP_;
-        r.gr[2] = _RET_IP_;
-        r.gr[30] = sp;
-        unwind_frame_init(&info, current, &r);
+        unwind_frame_init_task(&info, current, NULL);
 
         /* unwind stack */
-        ++level;
+        level += 2;
         do {
                 if (unwind_once(&info) < 0 || info.ip == 0)
                         return 0;