ARM: 8720/1: ensure dump_instr() checks addr_limit

[pandora-kernel.git] / arch / arm / kernel / traps.c

diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index d45fd22..9be66c1 100644 (file)
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -130,30 +130,26 @@ static void dump_mem(const char *lvl, const char *str, unsigned long bottom,
        set_fs(fs);
 }
 
-static void dump_instr(const char *lvl, struct pt_regs *regs)
+static void __dump_instr(const char *lvl, struct pt_regs *regs)
 {
        unsigned long addr = instruction_pointer(regs);
        const int thumb = thumb_mode(regs);
        const int width = thumb ? 4 : 8;
-       mm_segment_t fs;
        char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
        int i;
 
        /*
-        * We need to switch to kernel mode so that we can use __get_user
-        * to safely read from kernel space.  Note that we now dump the
-        * code first, just in case the backtrace kills us.
+        * Note that we now dump the code first, just in case the backtrace
+        * kills us.
         */
-       fs = get_fs();
-       set_fs(KERNEL_DS);
 
        for (i = -4; i < 1 + !!thumb; i++) {
                unsigned int val, bad;
 
                if (thumb)
-                       bad = __get_user(val, &((u16 *)addr)[i]);
+                       bad = get_user(val, &((u16 *)addr)[i]);
                else
-                       bad = __get_user(val, &((u32 *)addr)[i]);
+                       bad = get_user(val, &((u32 *)addr)[i]);
 
                if (!bad)
                        p += sprintf(p, i == 0 ? "(%0*x) " : "%0*x ",
@@ -164,8 +160,20 @@ static void dump_instr(const char *lvl, struct pt_regs *regs)
                }
        }
        printk("%sCode: %s\n", lvl, str);
+}
 
-       set_fs(fs);
+static void dump_instr(const char *lvl, struct pt_regs *regs)
+{
+       mm_segment_t fs;
+
+       if (!user_mode(regs)) {
+               fs = get_fs();
+               set_fs(KERNEL_DS);
+               __dump_instr(lvl, regs);
+               set_fs(fs);
+       } else {
+               __dump_instr(lvl, regs);
+       }
 }
 
 #ifdef CONFIG_ARM_UNWIND