This is an update to V2 which can be found here:
https://lkml.kernel.org/r/20190418084119.056416...@linutronix.de
Changes vs. V2:
- Fixed the kernel-doc issue pointed out by Mike
- Removed the '-1' oddity from the tracer
- Restricted the tracer nesting to 4
- Restored the lockdep magic to prevent redundant stack traces
- Addressed the small nitpicks here and there
- Picked up Acked/Reviewed tags
The series is based on:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git core/stacktrace
which contains the removal of the inconsistent and pointless ULONG_MAX
termination of stacktraces.
It's also available from git:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git WIP.core/stacktrace
up to 5160eb663575 ("x86/stacktrace: Use common infrastructure")
Delta patch vs. v2 below.
Thanks,
tglx
8<-
diff --git a/include/linux/stacktrace.h b/include/linux/stacktrace.h
index 654949dc1c16..f0cfd12cb45e 100644
--- a/include/linux/stacktrace.h
+++ b/include/linux/stacktrace.h
@@ -32,14 +32,13 @@ unsigned int stack_trace_save_user(unsigned long *store,
unsigned int size);
* @reliable: True when the stack entry is reliable. Required by
* some printk based consumers.
*
- * Returns:True, if the entry was consumed or skipped
+ * Return: True, if the entry was consumed or skipped
* False, if there is no space left to store
*/
typedef bool (*stack_trace_consume_fn)(void *cookie, unsigned long addr,
bool reliable);
/**
* arch_stack_walk - Architecture specific function to walk the stack
-
* @consume_entry: Callback which is invoked by the architecture code for
* each entry.
* @cookie:Caller supplied pointer which is handed back to
@@ -47,10 +46,12 @@ typedef bool (*stack_trace_consume_fn)(void *cookie,
unsigned long addr,
* @task: Pointer to a task struct, can be NULL
* @regs: Pointer to registers, can be NULL
*
- * @task @regs:
- * NULLNULLStack trace from current
+ * ===
+ * taskregs
+ * ===
* taskNULLStack trace from task (can be current)
- * NULLregsStack trace starting on regs->stackpointer
+ * current regsStack trace starting on regs->stackpointer
+ * ===
*/
void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
struct task_struct *task, struct pt_regs *regs);
diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c
index 1e8e246edaad..badd77670d00 100644
--- a/kernel/dma/debug.c
+++ b/kernel/dma/debug.c
@@ -705,7 +705,8 @@ static struct dma_debug_entry *dma_entry_alloc(void)
#ifdef CONFIG_STACKTRACE
entry->stack_len = stack_trace_save(entry->stack_entries,
- ARRAY_SIZE(entry->stack_entries),
1);
+ ARRAY_SIZE(entry->stack_entries),
+ 1);
#endif
return entry;
}
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 84423f0bb0b0..45bcaf2e4cb6 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -2160,12 +2160,11 @@ check_deadlock(struct task_struct *curr, struct
held_lock *next,
*/
static int
check_prev_add(struct task_struct *curr, struct held_lock *prev,
- struct held_lock *next, int distance)
+ struct held_lock *next, int distance, struct lock_trace *trace)
{
struct lock_list *uninitialized_var(target_entry);
struct lock_list *entry;
struct lock_list this;
- struct lock_trace trace;
int ret;
if (!hlock_class(prev)->key || !hlock_class(next)->key) {
@@ -2198,8 +2197,17 @@ check_prev_add(struct task_struct *curr, struct
held_lock *prev,
this.class = hlock_class(next);
this.parent = NULL;
ret = check_noncircular(, hlock_class(prev), _entry);
- if (unlikely(!ret))
+ if (unlikely(!ret)) {
+ if (!trace->nr_entries) {
+ /*
+* If save_trace fails here, the printing might
+* trigger a WARN but because of the !nr_entries it
+* should not do bad things.
+*/
+ save_trace(trace);
+ }
return print_circular_bug(, target_entry, next, prev);
+ }
else if (unlikely(ret < 0))
return print_bfs_bug(ret);
@@ -2246,7 +2254,7 @@ check_prev_add(struct task_struct *curr, struct held_lock
*prev,
return print_bfs_bug(ret);
- if (!save_trace())
+ if (!trace->nr_entries &&
