Commit 56a61617 authored by Zhaoyang Huang's avatar Zhaoyang Huang Committed by Andrew Morton
Browse files

mm: use stack_depot for recording kmemleak's backtrace 

Using stack_depot to record kmemleak's backtrace which has been
implemented on slub for reducing redundant information.

[akpm@linux-foundation.org: fix build - remove now-unused __save_stack_trace()]
[zhaoyang.huang@unisoc.com: v3]
  Link: https://lkml.kernel.org/r/1667101354-4669-1-git-send-email-zhaoyang.huang@unisoc.com
[akpm@linux-foundation.org: fix v3 layout oddities]
[akpm@linux-foundation.org: coding-style cleanups]
Link: https://lkml.kernel.org/r/1666864224-27541-1-git-send-email-zhaoyang.huang@unisoc.com


Signed-off-by: default avatarZhaoyang Huang <zhaoyang.huang@unisoc.com>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Cc: ke.wang <ke.wang@unisoc.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zhaoyang Huang <huangzhaoyang@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 9102b78b

lib/Kconfig.debug

+1 −0
Original line number Diff line number Diff line
@@ -728,6 +728,7 @@ config DEBUG_KMEMLEAK 
	select STACKTRACE if STACKTRACE_SUPPORT

	select KALLSYMS

	select CRC32

	select STACKDEPOT

	help

	  Say Y here if you want to enable the memory leak

	  detector. The memory allocation/freeing is traced in a way

mm/kmemleak.c

+28 −18
Original line number Diff line number Diff line
@@ -79,6 +79,7 @@ 
#include <linux/mutex.h>

#include <linux/rcupdate.h>

#include <linux/stacktrace.h>

#include <linux/stackdepot.h>

#include <linux/cache.h>

#include <linux/percpu.h>

#include <linux/memblock.h>
@@ -159,8 +160,7 @@ struct kmemleak_object { 
	u32 checksum;

	/* memory ranges to be scanned inside an object (empty for all) */

	struct hlist_head area_list;

	unsigned long trace[MAX_TRACE];

	unsigned int trace_len;

	depot_stack_handle_t trace_handle;

	unsigned long jiffies;		/* creation timestamp */

	pid_t pid;			/* pid of the current task */

	char comm[TASK_COMM_LEN];	/* executable name */
@@ -346,8 +346,11 @@ static void print_unreferenced(struct seq_file *seq, 
			       struct kmemleak_object *object)

{

	int i;

	unsigned long *entries;

	unsigned int nr_entries;

	unsigned int msecs_age = jiffies_to_msecs(jiffies - object->jiffies);



	nr_entries = stack_depot_fetch(object->trace_handle, &entries);

	warn_or_seq_printf(seq, "unreferenced object 0x%08lx (size %zu):\n",

			  object->pointer, object->size);

	warn_or_seq_printf(seq, "  comm \"%s\", pid %d, jiffies %lu (age %d.%03ds)\n",
@@ -356,8 +359,8 @@ static void print_unreferenced(struct seq_file *seq, 
	hex_dump_object(seq, object);

	warn_or_seq_printf(seq, "  backtrace:\n");



	for (i = 0; i < object->trace_len; i++) {

		void *ptr = (void *)object->trace[i];

	for (i = 0; i < nr_entries; i++) {

		void *ptr = (void *)entries[i];

		warn_or_seq_printf(seq, "    [<%p>] %pS\n", ptr, ptr);

	}

}
@@ -378,7 +381,8 @@ static void dump_object_info(struct kmemleak_object *object) 
	pr_notice("  flags = 0x%x\n", object->flags);

	pr_notice("  checksum = %u\n", object->checksum);

	pr_notice("  backtrace:\n");

	stack_trace_print(object->trace, object->trace_len, 4);

	if (object->trace_handle)

		stack_depot_print(object->trace_handle);

}



/*
@@ -591,12 +595,18 @@ static struct kmemleak_object *find_and_remove_object(unsigned long ptr, int ali 
	return object;

}



/*

 * Save stack trace to the given array of MAX_TRACE size.

 */

static int __save_stack_trace(unsigned long *trace)

static noinline depot_stack_handle_t set_track_prepare(void)

{

	return stack_trace_save(trace, MAX_TRACE, 2);

	depot_stack_handle_t trace_handle;

	unsigned long entries[MAX_TRACE];

	unsigned int nr_entries;



	if (!kmemleak_initialized)

		return 0;

	nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 3);

	trace_handle = stack_depot_save(entries, nr_entries, GFP_NOWAIT);



	return trace_handle;

}



/*
@@ -653,7 +663,7 @@ static void __create_object(unsigned long ptr, size_t size, 
	}



	/* kernel backtrace */

	object->trace_len = __save_stack_trace(object->trace);

	object->trace_handle = set_track_prepare();



	raw_spin_lock_irqsave(&kmemleak_lock, flags);
@@ -692,7 +702,6 @@ static void __create_object(unsigned long ptr, size_t size, 
	rb_link_node(&object->rb_node, rb_parent, link);

	rb_insert_color(&object->rb_node, is_phys ? &object_phys_tree_root :

					  &object_tree_root);



	list_add_tail_rcu(&object->object_list, &object_list);

out:

	raw_spin_unlock_irqrestore(&kmemleak_lock, flags);
@@ -1091,7 +1100,7 @@ void __ref kmemleak_update_trace(const void *ptr) 
	}



	raw_spin_lock_irqsave(&object->lock, flags);

	object->trace_len = __save_stack_trace(object->trace);

	object->trace_handle = set_track_prepare();

	raw_spin_unlock_irqrestore(&object->lock, flags);



	put_object(object);
@@ -2084,6 +2093,7 @@ void __init kmemleak_init(void) 
	if (kmemleak_error)

		return;



	stack_depot_init();

	jiffies_min_age = msecs_to_jiffies(MSECS_MIN_AGE);

	jiffies_scan_wait = msecs_to_jiffies(SECS_SCAN_WAIT * 1000);