Simplify the stack retrieval code by using the storage array based
interface.

Signed-off-by: Thomas Gleixner <t...@linutronix.de>
---
 kernel/trace/trace_stack.c |   42 ++++++++++++++++--------------------------
 1 file changed, 16 insertions(+), 26 deletions(-)

--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -23,16 +23,7 @@
 static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES];
 static unsigned stack_trace_index[STACK_TRACE_ENTRIES];
 
-/*
- * Reserve one entry for the passed in ip. This will allow
- * us to remove most or all of the stack size overhead
- * added by the stack tracer itself.
- */
-struct stack_trace stack_trace_max = {
-       .max_entries            = STACK_TRACE_ENTRIES - 1,
-       .entries                = &stack_dump_trace[0],
-};
-
+static unsigned int stack_trace_entries;
 static unsigned long stack_trace_max_size;
 static arch_spinlock_t stack_trace_max_lock =
        (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
@@ -49,10 +40,10 @@ static void print_max_stack(void)
 
        pr_emerg("        Depth    Size   Location    (%d entries)\n"
                           "        -----    ----   --------\n",
-                          stack_trace_max.nr_entries);
+                          stack_trace_entries);
 
-       for (i = 0; i < stack_trace_max.nr_entries; i++) {
-               if (i + 1 == stack_trace_max.nr_entries)
+       for (i = 0; i < stack_trace_entries; i++) {
+               if (i + 1 == stack_trace_entries)
                        size = stack_trace_index[i];
                else
                        size = stack_trace_index[i] - stack_trace_index[i+1];
@@ -98,13 +89,12 @@ static void check_stack(unsigned long ip
 
        stack_trace_max_size = this_size;
 
-       stack_trace_max.nr_entries = 0;
-       stack_trace_max.skip = 0;
-
-       save_stack_trace(&stack_trace_max);
+       stack_trace_entries = stack_trace_save(stack_dump_trace,
+                                              ARRAY_SIZE(stack_dump_trace) - 1,
+                                              0);
 
        /* Skip over the overhead of the stack tracer itself */
-       for (i = 0; i < stack_trace_max.nr_entries; i++) {
+       for (i = 0; i < stack_trace_entries; i++) {
                if (stack_dump_trace[i] == ip)
                        break;
        }
@@ -113,7 +103,7 @@ static void check_stack(unsigned long ip
         * Some archs may not have the passed in ip in the dump.
         * If that happens, we need to show everything.
         */
-       if (i == stack_trace_max.nr_entries)
+       if (i == stack_trace_entries)
                i = 0;
 
        /*
@@ -131,13 +121,13 @@ static void check_stack(unsigned long ip
         * loop will only happen once. This code only takes place
         * on a new max, so it is far from a fast path.
         */
-       while (i < stack_trace_max.nr_entries) {
+       while (i < stack_trace_entries) {
                int found = 0;
 
                stack_trace_index[x] = this_size;
                p = start;
 
-               for (; p < top && i < stack_trace_max.nr_entries; p++) {
+               for (; p < top && i < stack_trace_entries; p++) {
                        /*
                         * The READ_ONCE_NOCHECK is used to let KASAN know that
                         * this is not a stack-out-of-bounds error.
@@ -168,7 +158,7 @@ static void check_stack(unsigned long ip
                        i++;
        }
 
-       stack_trace_max.nr_entries = x;
+       stack_trace_entries = x;
 
        if (task_stack_end_corrupted(current)) {
                print_max_stack();
@@ -270,7 +260,7 @@ static void *
 {
        long n = *pos - 1;
 
-       if (n >= stack_trace_max.nr_entries)
+       if (n >= stack_trace_entries)
                return NULL;
 
        m->private = (void *)n;
@@ -334,7 +324,7 @@ static int t_show(struct seq_file *m, vo
                seq_printf(m, "        Depth    Size   Location"
                           "    (%d entries)\n"
                           "        -----    ----   --------\n",
-                          stack_trace_max.nr_entries);
+                          stack_trace_entries);
 
                if (!stack_tracer_enabled && !stack_trace_max_size)
                        print_disabled(m);
@@ -344,10 +334,10 @@ static int t_show(struct seq_file *m, vo
 
        i = *(long *)v;
 
-       if (i >= stack_trace_max.nr_entries)
+       if (i >= stack_trace_entries)
                return 0;
 
-       if (i + 1 == stack_trace_max.nr_entries)
+       if (i + 1 == stack_trace_entries)
                size = stack_trace_index[i];
        else
                size = stack_trace_index[i] - stack_trace_index[i+1];


--
dm-devel mailing list
dm-devel@redhat.com
https://www.redhat.com/mailman/listinfo/dm-devel

Reply via email to