um: Add support for CONFIG_STACKTRACE

Add stacktrace support for User Mode Linux

Signed-off-by: Daniel Walter <dwalter@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

1 files changed, 17 insertions, 52 deletions

diff --git a/arch/um/kernel/sysrq.c b/arch/um/kernel/sysrq.c
index 799d7e413bf5..894c8d303cda 100644
--- a/arch/um/kernel/sysrq.c
+++ b/arch/um/kernel/sysrq.c
@@ -12,57 +12,20 @@
 #include <linux/module.h>
 #include <linux/sched.h>
 #include <asm/sysrq.h>
+#include <asm/stacktrace.h>
 #include <os.h>
 
-struct stack_frame {
-        struct stack_frame *next_frame;
-        unsigned long return_address;
-};
-
-static void do_stack_trace(unsigned long *sp, unsigned long bp)
+static void _print_addr(void *data, unsigned long address, int reliable)
 {
-        int reliable;
-        unsigned long addr;
-        struct stack_frame *frame = (struct stack_frame *)bp;
-
-        printk(KERN_INFO "Call Trace:\n");
-        while (((long) sp & (THREAD_SIZE-1)) != 0) {
-                addr = *sp;
-                if (__kernel_text_address(addr)) {
-                        reliable = 0;
-                        if ((unsigned long) sp == bp + sizeof(long)) {
-                                frame = frame ? frame->next_frame : NULL;
-                                bp = (unsigned long)frame;
-                                reliable = 1;
-                        }
-
-                        printk(KERN_INFO " [<%08lx>]", addr);
-                        printk(KERN_CONT " %s", reliable ? "" : "? ");
-                        print_symbol(KERN_CONT "%s", addr);
-                        printk(KERN_CONT "\n");
-                }
-                sp++;
-        }
-        printk(KERN_INFO "\n");
+        pr_info(" [<%08lx>]", address);
+        pr_cont(" %s", reliable ? "" : "? ");
+        print_symbol("%s", address);
+        pr_cont("\n");
 }
 
-static unsigned long get_frame_pointer(struct task_struct *task,
-                                       struct pt_regs *segv_regs)
-{
-        if (!task || task == current)
-                return segv_regs ? PT_REGS_BP(segv_regs) : current_bp();
-        else
-                return KSTK_EBP(task);
-}
-
-static unsigned long *get_stack_pointer(struct task_struct *task,
-                                        struct pt_regs *segv_regs)
-{
-        if (!task || task == current)
-                return segv_regs ? (unsigned long *)PT_REGS_SP(segv_regs) : current_sp();
-        else
-                return (unsigned long *)KSTK_ESP(task);
-}
+static const struct stacktrace_ops stackops = {
+        .address = _print_addr
+};
 
 void show_stack(struct task_struct *task, unsigned long *stack)
 {
@@ -71,7 +34,7 @@ void show_stack(struct task_struct *task, unsigned long *stack)
         int i;
 
         if (!segv_regs && os_is_signal_stack()) {
-                printk(KERN_ERR "Received SIGSEGV in SIGSEGV handler,"
+                pr_err("Received SIGSEGV in SIGSEGV handler,"
                                 " aborting stack trace!\n");
                 return;
         }
@@ -83,16 +46,18 @@ void show_stack(struct task_struct *task, unsigned long *stack)
         if (!stack)
                 sp = get_stack_pointer(task, segv_regs);
 
-        printk(KERN_INFO "Stack:\n");
+        pr_info("Stack:\n");
         stack = sp;
         for (i = 0; i < 3 * STACKSLOTS_PER_LINE; i++) {
                 if (kstack_end(stack))
                         break;
                 if (i && ((i % STACKSLOTS_PER_LINE) == 0))
-                        printk(KERN_CONT "\n");
-                printk(KERN_CONT " %08lx", *stack++);
+                        pr_cont("\n");
+                pr_cont(" %08lx", *stack++);
         }
-        printk(KERN_CONT "\n");
+        pr_cont("\n");
 
-        do_stack_trace(sp, bp);
+        pr_info("Call Trace:\n");
+        dump_trace(current, &stackops, NULL);
+        pr_info("\n");
 }