sh: stacktrace/lockdep/irqflags tracing support.

Wire up all of the essentials for lockdep..

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

8 files changed, 139 insertions, 2 deletions

diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index aa1ebc561b84..013732074d35 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -51,6 +51,14 @@ config GENERIC_TIME
 config ARCH_MAY_HAVE_PC_FDC
         bool
 
+config STACKTRACE_SUPPORT
+        bool
+        default y
+
+config LOCKDEP_SUPPORT
+        bool
+        default y
+
 source "init/Kconfig"
 
 menu "System type"
diff --git a/arch/sh/Kconfig.debug b/arch/sh/Kconfig.debug
index dcceec95a2d5..66a25ef4ef1b 100644
--- a/arch/sh/Kconfig.debug
+++ b/arch/sh/Kconfig.debug
@@ -1,5 +1,9 @@
 menu "Kernel hacking"
 
+config TRACE_IRQFLAGS_SUPPORT
+        bool
+        default y
+
 source "lib/Kconfig.debug"
 
 config SH_STANDARD_BIOS
diff --git a/arch/sh/kernel/Makefile b/arch/sh/kernel/Makefile
index 50d54c24d76a..99c7e5249f7a 100644
--- a/arch/sh/kernel/Makefile
+++ b/arch/sh/kernel/Makefile
@@ -21,3 +21,4 @@ obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
 obj-$(CONFIG_KEXEC)             += machine_kexec.o relocate_kernel.o
 obj-$(CONFIG_APM)               += apm.o
 obj-$(CONFIG_PM)                += pm.o
+obj-$(CONFIG_STACKTRACE)        += stacktrace.o
diff --git a/arch/sh/kernel/cpu/sh2/entry.S b/arch/sh/kernel/cpu/sh2/entry.S
index 298d9191909d..34d51b3745ea 100644
--- a/arch/sh/kernel/cpu/sh2/entry.S
+++ b/arch/sh/kernel/cpu/sh2/entry.S
@@ -184,6 +184,11 @@ trap_entry:
         add     r15,r8
         mov.l   r9,@r8
         mov     r9,r8
+#ifdef CONFIG_TRACE_IRQFLAGS
+        mov.l   5f, r9
+        jsr     @r9
+         nop
+#endif
         sti
         bra     system_call
          nop
@@ -193,6 +198,9 @@ trap_entry:
 2:      .long   break_point_trap_software
 3:      .long   NR_syscalls
 4:      .long   sys_call_table
+#ifdef CONFIG_TRACE_IRQFLAGS
+5:      .long   trace_hardirqs_on
+#endif
 
 #if defined(CONFIG_SH_STANDARD_BIOS)
         /* Unwind the stack and jmp to the debug entry */
@@ -255,6 +263,11 @@ ENTRY(address_error_handler)
 
 restore_all:
         cli
+#ifdef CONFIG_TRACE_IRQFLAGS
+        mov.l   3f, r0
+        jsr     @r0
+         nop
+#endif
         mov     r15,r0
         mov.l   $cpu_mode,r2
         mov     #OFF_SR,r3
@@ -307,6 +320,9 @@ $current_thread_info:
         .long   __current_thread_info
 $cpu_mode:      
         .long   __cpu_mode
+#ifdef CONFIG_TRACE_IRQFLAGS
+3:      .long   trace_hardirqs_off
+#endif
                 
 ! common exception handler
 #include "../../entry-common.S"
diff --git a/arch/sh/kernel/cpu/sh3/entry.S b/arch/sh/kernel/cpu/sh3/entry.S
index 7ba3dcbe7504..8c0dc2700c69 100644
--- a/arch/sh/kernel/cpu/sh3/entry.S
+++ b/arch/sh/kernel/cpu/sh3/entry.S
@@ -140,7 +140,7 @@ call_dpf:
         mov.l   1f, r0
         mov.l   @r0, r6         ! address
         mov.l   3f, r0
-        sti
+
         jmp     @r0
          mov    r15, r4         ! regs
 
diff --git a/arch/sh/kernel/entry-common.S b/arch/sh/kernel/entry-common.S
index 8f96d21fcb1c..29136a35d7c7 100644
--- a/arch/sh/kernel/entry-common.S
+++ b/arch/sh/kernel/entry-common.S
@@ -100,6 +100,11 @@ debug_trap:
         .align  2
 ENTRY(exception_error)
         !
+#ifdef CONFIG_TRACE_IRQFLAGS
+        mov.l   3f, r0
+        jsr     @r0
+         nop
+#endif
         sti
         mov.l   2f, r0
         jmp     @r0
@@ -109,10 +114,18 @@ ENTRY(exception_error)
         .align  2
 1:      .long   break_point_trap_software
 2:      .long   do_exception_error
+#ifdef CONFIG_TRACE_IRQFLAGS
+3:      .long   trace_hardirqs_on
+#endif
 
         .align  2
 ret_from_exception:
         preempt_stop()
+#ifdef CONFIG_TRACE_IRQFLAGS
+        mov.l   4f, r0
+        jsr     @r0
+         nop
+#endif
 ENTRY(ret_from_irq)
         !
         mov     #OFF_SR, r0
@@ -143,6 +156,11 @@ need_resched:
         mov.l   1f, r0
         mov.l   r0, @(TI_PRE_COUNT,r8)
 
+#ifdef CONFIG_TRACE_IRQFLAGS
+        mov.l   3f, r0
+        jsr     @r0
+         nop
+#endif
         sti
         mov.l   2f, r0
         jsr     @r0
@@ -150,9 +168,15 @@ need_resched:
         mov     #0, r0
         mov.l   r0, @(TI_PRE_COUNT,r8)
         cli
+#ifdef CONFIG_TRACE_IRQFLAGS
+        mov.l   4f, r0
+        jsr     @r0
+         nop
+#endif
 
         bra     need_resched
          nop
+
 noresched:
         bra     __restore_all
          nop
@@ -160,11 +184,20 @@ noresched:
         .align 2
 1:      .long   PREEMPT_ACTIVE
 2:      .long   schedule
+#ifdef CONFIG_TRACE_IRQFLAGS
+3:      .long   trace_hardirqs_on
+4:      .long   trace_hardirqs_off
+#endif
 #endif
 
 ENTRY(resume_userspace)
         ! r8: current_thread_info
         cli
+#ifdef CONFIG_TRACE_IRQFLAGS
+        mov.l   5f, r0
+        jsr     @r0
+         nop
+#endif
         mov.l   @(TI_FLAGS,r8), r0              ! current_thread_info->flags
         tst     #_TIF_WORK_MASK, r0
         bt/s    __restore_all
@@ -210,6 +243,11 @@ work_resched:
         jsr     @r1                             ! schedule
          nop
         cli
+#ifdef CONFIG_TRACE_IRQFLAGS
+        mov.l   5f, r0
+        jsr     @r0
+         nop
+#endif
         !
         mov.l   @(TI_FLAGS,r8), r0              ! current_thread_info->flags
         tst     #_TIF_WORK_MASK, r0
@@ -221,6 +259,10 @@ work_resched:
 1:      .long   schedule
 2:      .long   do_notify_resume
 3:      .long   restore_all
+#ifdef CONFIG_TRACE_IRQFLAGS
+4:      .long   trace_hardirqs_on
+5:      .long   trace_hardirqs_off
+#endif
 
         .align  2
 syscall_exit_work:
@@ -229,6 +271,11 @@ syscall_exit_work:
         tst     #_TIF_SYSCALL_TRACE, r0
         bt/s    work_pending
          tst    #_TIF_NEED_RESCHED, r0
+#ifdef CONFIG_TRACE_IRQFLAGS
+        mov.l   5f, r0
+        jsr     @r0
+         nop
+#endif
         sti
         ! XXX setup arguments...
         mov.l   4f, r0                  ! do_syscall_trace
@@ -265,7 +312,7 @@ syscall_trace_entry:
          mov.l  r0, @(OFF_R0,r15)       ! Return value
 
 __restore_all:
-        mov.l   1f,r0
+        mov.l   1f, r0
         jmp     @r0
          nop
 
@@ -331,7 +378,13 @@ ENTRY(system_call)
          mov    #OFF_TRA, r9
         add     r15, r9
         mov.l   r8, @r9                 ! set TRA value to tra
+#ifdef CONFIG_TRACE_IRQFLAGS
+        mov.l   5f, r10
+        jsr     @r10
+         nop
+#endif
         sti
+
         !
         get_current_thread_info r8, r10
         mov.l   @(TI_FLAGS,r8), r8
@@ -355,6 +408,11 @@ syscall_call:
         !
 syscall_exit:
         cli
+#ifdef CONFIG_TRACE_IRQFLAGS
+        mov.l   6f, r0
+        jsr     @r0
+         nop
+#endif
         !
         get_current_thread_info r8, r0
         mov.l   @(TI_FLAGS,r8), r0              ! current_thread_info->flags
@@ -369,3 +427,7 @@ syscall_exit:
 2:      .long   NR_syscalls
 3:      .long   sys_call_table
 4:      .long   do_syscall_trace
+#ifdef CONFIG_TRACE_IRQFLAGS
+5:      .long   trace_hardirqs_on
+6:      .long   trace_hardirqs_off
+#endif
diff --git a/arch/sh/kernel/stacktrace.c b/arch/sh/kernel/stacktrace.c
new file mode 100644
index 000000000000..0d5268afe80f
--- /dev/null
+++ b/arch/sh/kernel/stacktrace.c
@@ -0,0 +1,43 @@
+/*
+ * arch/sh/kernel/stacktrace.c
+ *
+ * Stack trace management functions
+ *
+ *  Copyright (C) 2006  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
+ * for more details.
+ */
+#include <linux/sched.h>
+#include <linux/stacktrace.h>
+#include <linux/thread_info.h>
+#include <asm/ptrace.h>
+
+/*
+ * Save stack-backtrace addresses into a stack_trace buffer.
+ */
+void save_stack_trace(struct stack_trace *trace, struct task_struct *task)
+{
+        unsigned long *sp;
+
+        if (!task)
+                task = current;
+        if (task == current)
+                sp = (unsigned long *)current_stack_pointer;
+        else
+                sp = (unsigned long *)task->thread.sp;
+
+        while (!kstack_end(sp)) {
+                unsigned long addr = *sp++;
+
+                if (__kernel_text_address(addr)) {
+                        if (trace->skip > 0)
+                                trace->skip--;
+                        else
+                                trace->entries[trace->nr_entries++] = addr;
+                        if (trace->nr_entries >= trace->max_entries)
+                                break;
+                }
+        }
+}
diff --git a/arch/sh/mm/fault.c b/arch/sh/mm/fault.c
index cfeefc10e254..716ebf568af2 100644
--- a/arch/sh/mm/fault.c
+++ b/arch/sh/mm/fault.c
@@ -37,6 +37,9 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
         int si_code;
         siginfo_t info;
 
+        trace_hardirqs_on();
+        local_irq_enable();
+
 #ifdef CONFIG_SH_KGDB
         if (kgdb_nofault && kgdb_bus_err_hook)
                 kgdb_bus_err_hook();