sh: Use the generalized stacktrace ops

Copy the stacktrace ops code from x86 and provide a central function for
use by functions that need to dump a callstack.

Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 128 insertions, 0 deletions

diff --git a/arch/sh/kernel/dumpstack.c b/arch/sh/kernel/dumpstack.c
new file mode 100644
index 000000000000..6ab996fc6121
--- /dev/null
+++ b/arch/sh/kernel/dumpstack.c
@@ -0,0 +1,128 @@
+/*
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *  Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
+ *  Copyright (C) 2009  Matt Fleming
+ */
+#include <linux/kallsyms.h>
+#include <linux/ftrace.h>
+#include <linux/debug_locks.h>
+
+#include <asm/stacktrace.h>
+
+void printk_address(unsigned long address, int reliable)
+{
+        printk(" [<%p>] %s%pS\n", (void *) address,
+                        reliable ? "" : "? ", (void *) address);
+}
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+static void
+print_ftrace_graph_addr(unsigned long addr, void *data,
+                        const struct stacktrace_ops *ops,
+                        struct thread_info *tinfo, int *graph)
+{
+        struct task_struct *task = tinfo->task;
+        unsigned long ret_addr;
+        int index = task->curr_ret_stack;
+
+        if (addr != (unsigned long)return_to_handler)
+                return;
+
+        if (!task->ret_stack || index < *graph)
+                return;
+
+        index -= *graph;
+        ret_addr = task->ret_stack[index].ret;
+
+        ops->address(data, ret_addr, 1);
+
+        (*graph)++;
+}
+#else
+static inline void
+print_ftrace_graph_addr(unsigned long addr, void *data,
+                        const struct stacktrace_ops *ops,
+                        struct thread_info *tinfo, int *graph)
+{ }
+#endif
+
+/*
+ * Unwind the call stack and pass information to the stacktrace_ops
+ * functions.
+ */
+void dump_trace(struct task_struct *task, struct pt_regs *regs,
+                unsigned long *sp, const struct stacktrace_ops *ops,
+                void *data)
+{
+        struct thread_info *context;
+        int graph = 0;
+
+        context = (struct thread_info *)
+                ((unsigned long)sp & (~(THREAD_SIZE - 1)));
+
+        while (!kstack_end(sp)) {
+                unsigned long addr = *sp++;
+
+                if (__kernel_text_address(addr)) {
+                        ops->address(data, addr, 0);
+
+                        print_ftrace_graph_addr(addr, data, ops,
+                                                context, &graph);
+                }
+        }
+}
+EXPORT_SYMBOL(dump_trace);
+
+
+static void
+print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
+{
+        printk(data);
+        print_symbol(msg, symbol);
+        printk("\n");
+}
+
+static void print_trace_warning(void *data, char *msg)
+{
+        printk("%s%s\n", (char *)data, msg);
+}
+
+static int print_trace_stack(void *data, char *name)
+{
+        printk("%s <%s> ", (char *)data, name);
+        return 0;
+}
+
+/*
+ * Print one address/symbol entries per line.
+ */
+static void print_trace_address(void *data, unsigned long addr, int reliable)
+{
+        printk(data);
+        printk_address(addr, reliable);
+}
+
+static const struct stacktrace_ops print_trace_ops = {
+        .warning = print_trace_warning,
+        .warning_symbol = print_trace_warning_symbol,
+        .stack = print_trace_stack,
+        .address = print_trace_address,
+};
+
+void show_trace(struct task_struct *tsk, unsigned long *sp,
+                struct pt_regs *regs)
+{
+        if (regs && user_mode(regs))
+                return;
+
+        printk("\nCall trace:\n");
+
+        dump_trace(tsk, regs, sp, &print_trace_ops, "");
+
+        printk("\n");
+
+        if (!tsk)
+                tsk = current;
+
+        debug_show_held_locks(tsk);
+}