Commit b8ca7ff7 authored Apr 10, 2019 by Thomas Gleixner

mm/slub: Remove the ULONG_MAX stack trace hackery



No architecture terminates the stack trace with ULONG_MAX anymore. Remove
the cruft.

While at it remove the pointless loop of clearing the stack array
completely. It's sufficient to clear the last entry as the consumers break
out on the first zeroed entry anyway.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: linux-mm@kvack.org
Cc: David Rientjes <rientjes@google.com>
Cc: Christoph Lameter <cl@linux.com>
Link: https://lkml.kernel.org/r/20190410103644.574058244@linutronix.de

parent 2dfed456

mm/slub.c

+4 −9

Original line number	Diff line number	Diff line
		@@ -553,7 +553,6 @@ static void set_track(struct kmem_cache s, void object,
		if (addr) {
		#ifdef CONFIG_STACKTRACE
		struct stack_trace trace;
		int i;

		trace.nr_entries = 0;
		trace.max_entries = TRACK_ADDRS_COUNT;
		@@ -563,21 +562,17 @@ static void set_track(struct kmem_cache s, void object,
		save_stack_trace(&trace);
		metadata_access_disable();

		/* See rant in lockdep.c */
		if (trace.nr_entries != 0 &&
		trace.entries[trace.nr_entries - 1] == ULONG_MAX)
		trace.nr_entries--;

		for (i = trace.nr_entries; i < TRACK_ADDRS_COUNT; i++)
		p->addrs[i] = 0;
		if (trace.nr_entries < TRACK_ADDRS_COUNT)
		p->addrs[trace.nr_entries] = 0;
		#endif
		p->addr = addr;
		p->cpu = smp_processor_id();
		p->pid = current->pid;
		p->when = jiffies;
		} else
		} else {
		memset(p, 0, sizeof(struct track));
		}
		}

		static void init_tracking(struct kmem_cache s, void object)
		{

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