[PATCH] i386: reliable stack trace support (i386)

[firefly-linux-kernel-4.4.55.git] / arch / i386 / kernel / traps.c

diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c
index dcc14477af1f0a5d16e083252389ba1d74173eac..2865846678652d2eb0fc7a6d229f7b4c99e13c36 100644 (file)
--- a/arch/i386/kernel/traps.c
+++ b/arch/i386/kernel/traps.c
@@ -28,6 +28,7 @@
 #include <linux/utsname.h>
 #include <linux/kprobes.h>
 #include <linux/kexec.h>
+#include <linux/unwind.h>
 
 #ifdef CONFIG_EISA
 #include <linux/ioport.h>
@@ -47,7 +48,7 @@
 #include <asm/desc.h>
 #include <asm/i387.h>
 #include <asm/nmi.h>
-
+#include <asm/unwind.h>
 #include <asm/smp.h>
 #include <asm/arch_hooks.h>
 #include <asm/kdebug.h>
@@ -170,14 +171,43 @@ static inline unsigned long print_context_stack(struct thread_info *tinfo,
        return ebp;
 }
 
-static void show_trace_log_lvl(struct task_struct *task,
+static asmlinkage void show_trace_unwind(struct unwind_frame_info *info, void *log_lvl)
+{
+       int printed = 0; /* nr of entries already printed on current line */
+
+       while (unwind(info) == 0 && UNW_PC(info)) {
+               printed = print_addr_and_symbol(UNW_PC(info), log_lvl, printed);
+               if (arch_unw_user_mode(info))
+                       break;
+       }
+       if (printed)
+               printk("\n");
+}
+
+static void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
                               unsigned long *stack, char *log_lvl)
 {
        unsigned long ebp;
+       struct unwind_frame_info info;
 
        if (!task)
                task = current;
 
+       if (regs) {
+               if (unwind_init_frame_info(&info, task, regs) == 0) {
+                       show_trace_unwind(&info, log_lvl);
+                       return;
+               }
+       } else if (task == current) {
+               if (unwind_init_running(&info, show_trace_unwind, log_lvl) == 0)
+                       return;
+       } else {
+               if (unwind_init_blocked(&info, task) == 0) {
+                       show_trace_unwind(&info, log_lvl);
+                       return;
+               }
+       }
+
        if (task == current) {
                /* Grab ebp right from our regs */
                asm ("movl %%ebp, %0" : "=r" (ebp) : );
@@ -198,13 +228,13 @@ static void show_trace_log_lvl(struct task_struct *task,
        }
 }
 
-void show_trace(struct task_struct *task, unsigned long * stack)
+void show_trace(struct task_struct *task, struct pt_regs *regs, unsigned long * stack)
 {
-       show_trace_log_lvl(task, stack, "");
+       show_trace_log_lvl(task, regs, stack, "");
 }
 
-static void show_stack_log_lvl(struct task_struct *task, unsigned long *esp,
-                              char *log_lvl)
+static void show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
+                              unsigned long *esp, char *log_lvl)
 {
        unsigned long *stack;
        int i;
@@ -225,13 +255,13 @@ static void show_stack_log_lvl(struct task_struct *task, unsigned long *esp,
                printk("%08lx ", *stack++);
        }
        printk("\n%sCall Trace:\n", log_lvl);
-       show_trace_log_lvl(task, esp, log_lvl);
+       show_trace_log_lvl(task, regs, esp, log_lvl);
 }
 
 void show_stack(struct task_struct *task, unsigned long *esp)
 {
        printk("       ");
-       show_stack_log_lvl(task, esp, "");
+       show_stack_log_lvl(task, NULL, esp, "");
 }
 
 /*
@@ -241,7 +271,7 @@ void dump_stack(void)
 {
        unsigned long stack;
 
-       show_trace(current, &stack);
+       show_trace(current, NULL, &stack);
 }
 
 EXPORT_SYMBOL(dump_stack);
@@ -285,7 +315,7 @@ void show_registers(struct pt_regs *regs)
                u8 __user *eip;
 
                printk("\n" KERN_EMERG "Stack: ");
-               show_stack_log_lvl(NULL, (unsigned long *)esp, KERN_EMERG);
+               show_stack_log_lvl(NULL, regs, (unsigned long *)esp, KERN_EMERG);
 
                printk(KERN_EMERG "Code: ");