s390/test_unwind: print verbose unwinding results

Add stack name, sp and reliable information into test unwinding
results. Also consider ip outside of kernel text as failure if the
state is reported reliable.

Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

diff --git a/arch/s390/kernel/dumpstack.c b/arch/s390/kernel/dumpstack.c
index fc442aec0d9633dc3228ecc6f2fd218696134b37..d74e21a23703ed77f5e7bd5f6da438189de335fd 100644 (file)
--- a/arch/s390/kernel/dumpstack.c
+++ b/arch/s390/kernel/dumpstack.c
@@ -38,6 +38,7 @@ const char *stack_type_name(enum stack_type type)
                return "unknown";
        }
 }
+EXPORT_SYMBOL_GPL(stack_type_name);
 
 static inline bool in_stack(unsigned long sp, struct stack_info *info,
                            enum stack_type type, unsigned long low,

diff --git a/arch/s390/lib/test_unwind.c b/arch/s390/lib/test_unwind.c
index 687a6922bedaa041b0961fc30650d764a2e549b4..db94e657c056dd6d974c16c6f29026b4d80635d6 100644 (file)
--- a/arch/s390/lib/test_unwind.c
+++ b/arch/s390/lib/test_unwind.c
@@ -56,11 +56,19 @@ static noinline int test_unwind(struct task_struct *task, struct pt_regs *regs,
                unsigned long addr = unwind_get_return_address(&state);
                char sym[KSYM_SYMBOL_LEN];
 
-               if (!addr || frame_count == max_frames)
+               if (frame_count++ == max_frames)
                        break;
+               if (state.reliable && !addr) {
+                       pr_err("unwind state reliable but addr is 0\n");
+                       return -EINVAL;
+               }
                sprint_symbol(sym, addr);
                if (bt_pos < BT_BUF_SIZE) {
-                       bt_pos += snprintf(bt + bt_pos, BT_BUF_SIZE - bt_pos, "%s\n", sym);
+                       bt_pos += snprintf(bt + bt_pos, BT_BUF_SIZE - bt_pos,
+                                          state.reliable ? " [%-7s%px] %pSR\n" :
+                                                           "([%-7s%px] %pSR)\n",
+                                          stack_type_name(state.stack_info.type),
+                                          (void *)state.sp, (void *)state.ip);
                        if (bt_pos >= BT_BUF_SIZE)
                                pr_err("backtrace buffer is too small\n");
                }