diff options
Diffstat (limited to 'scripts/gdb/linux/slab.py')
| -rw-r--r-- | scripts/gdb/linux/slab.py | 325 |
1 files changed, 325 insertions, 0 deletions
diff --git a/scripts/gdb/linux/slab.py b/scripts/gdb/linux/slab.py new file mode 100644 index 000000000000..0e2d93867fe2 --- /dev/null +++ b/scripts/gdb/linux/slab.py @@ -0,0 +1,325 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Copyright (c) 2023 MediaTek Inc. +# +# Authors: +# Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com> +# + +import gdb +import re +import traceback +from linux import lists, utils, stackdepot, constants, mm + +SLAB_RED_ZONE = constants.LX_SLAB_RED_ZONE +SLAB_POISON = constants.LX_SLAB_POISON +SLAB_KMALLOC = constants.LX_SLAB_KMALLOC +SLAB_HWCACHE_ALIGN = constants.LX_SLAB_HWCACHE_ALIGN +SLAB_CACHE_DMA = constants.LX_SLAB_CACHE_DMA +SLAB_CACHE_DMA32 = constants.LX_SLAB_CACHE_DMA32 +SLAB_STORE_USER = constants.LX_SLAB_STORE_USER +SLAB_PANIC = constants.LX_SLAB_PANIC + +OO_SHIFT = 16 +OO_MASK = (1 << OO_SHIFT) - 1 + +if constants.LX_CONFIG_SLUB_DEBUG: + slab_type = utils.CachedType("struct slab") + slab_ptr_type = slab_type.get_type().pointer() + kmem_cache_type = utils.CachedType("struct kmem_cache") + kmem_cache_ptr_type = kmem_cache_type.get_type().pointer() + freeptr_t = utils.CachedType("freeptr_t") + freeptr_t_ptr = freeptr_t.get_type().pointer() + + track_type = gdb.lookup_type('struct track') + track_alloc = int(gdb.parse_and_eval('TRACK_ALLOC')) + track_free = int(gdb.parse_and_eval('TRACK_FREE')) + +def slab_folio(slab): + return slab.cast(gdb.lookup_type("struct folio").pointer()) + +def slab_address(slab): + p_ops = mm.page_ops().ops + folio = slab_folio(slab) + return p_ops.folio_address(folio) + +def for_each_object(cache, addr, slab_objects): + p = addr + if cache['flags'] & SLAB_RED_ZONE: + p += int(cache['red_left_pad']) + while p < addr + (slab_objects * cache['size']): + yield p + p = p + int(cache['size']) + +def get_info_end(cache): + if (cache['offset'] >= cache['inuse']): + return cache['inuse'] + gdb.lookup_type("void").pointer().sizeof + else: + return cache['inuse'] + +def get_orig_size(cache, obj): + if cache['flags'] & SLAB_STORE_USER and cache['flags'] & SLAB_KMALLOC: + p = mm.page_ops().ops.kasan_reset_tag(obj) + p += get_info_end(cache) + p += gdb.lookup_type('struct track').sizeof * 2 + p = p.cast(utils.get_uint_type().pointer()) + return p.dereference() + else: + return cache['object_size'] + +def get_track(cache, object_pointer, alloc): + p = object_pointer + get_info_end(cache) + p += (alloc * track_type.sizeof) + return p + +def oo_objects(x): + return int(x['x']) & OO_MASK + +def oo_order(x): + return int(x['x']) >> OO_SHIFT + +def reciprocal_divide(a, R): + t = (a * int(R['m'])) >> 32 + return (t + ((a - t) >> int(R['sh1']))) >> int(R['sh2']) + +def __obj_to_index(cache, addr, obj): + return reciprocal_divide(int(mm.page_ops().ops.kasan_reset_tag(obj)) - addr, cache['reciprocal_size']) + +def swab64(x): + result = (((x & 0x00000000000000ff) << 56) | \ + ((x & 0x000000000000ff00) << 40) | \ + ((x & 0x0000000000ff0000) << 24) | \ + ((x & 0x00000000ff000000) << 8) | \ + ((x & 0x000000ff00000000) >> 8) | \ + ((x & 0x0000ff0000000000) >> 24) | \ + ((x & 0x00ff000000000000) >> 40) | \ + ((x & 0xff00000000000000) >> 56)) + return result + +def freelist_ptr_decode(cache, ptr, ptr_addr): + if constants.LX_CONFIG_SLAB_FREELIST_HARDENED: + return ptr['v'] ^ cache['random'] ^ swab64(int(ptr_addr)) + else: + return ptr['v'] + +def get_freepointer(cache, obj): + obj = mm.page_ops().ops.kasan_reset_tag(obj) + ptr_addr = obj + cache['offset'] + p = ptr_addr.cast(freeptr_t_ptr).dereference() + return freelist_ptr_decode(cache, p, ptr_addr) + +def loc_exist(loc_track, addr, handle, waste): + for loc in loc_track: + if loc['addr'] == addr and loc['handle'] == handle and loc['waste'] == waste: + return loc + return None + +def add_location(loc_track, cache, track, orig_size): + jiffies = gdb.parse_and_eval("jiffies_64") + age = jiffies - track['when'] + handle = 0 + waste = cache['object_size'] - int(orig_size) + pid = int(track['pid']) + cpuid = int(track['cpu']) + addr = track['addr'] + if constants.LX_CONFIG_STACKDEPOT: + handle = track['handle'] + + loc = loc_exist(loc_track, addr, handle, waste) + if loc: + loc['count'] += 1 + if track['when']: + loc['sum_time'] += age + loc['min_time'] = min(loc['min_time'], age) + loc['max_time'] = max(loc['max_time'], age) + loc['min_pid'] = min(loc['min_pid'], pid) + loc['max_pid'] = max(loc['max_pid'], pid) + loc['cpus'].add(cpuid) + else: + loc_track.append({ + 'count' : 1, + 'addr' : addr, + 'sum_time' : age, + 'min_time' : age, + 'max_time' : age, + 'min_pid' : pid, + 'max_pid' : pid, + 'handle' : handle, + 'waste' : waste, + 'cpus' : {cpuid} + } + ) + +def slabtrace(alloc, cache_name): + + def __fill_map(obj_map, cache, slab): + p = slab['freelist'] + addr = slab_address(slab) + while p != gdb.Value(0): + index = __obj_to_index(cache, addr, p) + obj_map[index] = True # free objects + p = get_freepointer(cache, p) + + # process every slab page on the slab_list (partial and full list) + def process_slab(loc_track, slab_list, alloc, cache): + for slab in lists.list_for_each_entry(slab_list, slab_ptr_type, "slab_list"): + obj_map[:] = [False] * oo_objects(cache['oo']) + __fill_map(obj_map, cache, slab) + addr = slab_address(slab) + for object_pointer in for_each_object(cache, addr, slab['objects']): + if obj_map[__obj_to_index(cache, addr, object_pointer)] == True: + continue + p = get_track(cache, object_pointer, alloc) + track = gdb.Value(p).cast(track_type.pointer()) + if alloc == track_alloc: + size = get_orig_size(cache, object_pointer) + else: + size = cache['object_size'] + add_location(loc_track, cache, track, size) + continue + + slab_caches = gdb.parse_and_eval("slab_caches") + if mm.page_ops().ops.MAX_NUMNODES > 1: + nr_node_ids = int(gdb.parse_and_eval("nr_node_ids")) + else: + nr_node_ids = 1 + + target_cache = None + loc_track = [] + + for cache in lists.list_for_each_entry(slab_caches, kmem_cache_ptr_type, 'list'): + if cache['name'].string() == cache_name: + target_cache = cache + break + + obj_map = [False] * oo_objects(target_cache['oo']) + + if target_cache['flags'] & SLAB_STORE_USER: + for i in range(0, nr_node_ids): + cache_node = target_cache['node'][i] + if cache_node['nr_slabs']['counter'] == 0: + continue + process_slab(loc_track, cache_node['partial'], alloc, target_cache) + process_slab(loc_track, cache_node['full'], alloc, target_cache) + else: + raise gdb.GdbError("SLAB_STORE_USER is not set in %s" % target_cache['name'].string()) + + for loc in sorted(loc_track, key=lambda x:x['count'], reverse=True): + if loc['addr']: + addr = loc['addr'].cast(utils.get_ulong_type().pointer()) + gdb.write("%d %s" % (loc['count'], str(addr).split(' ')[-1])) + else: + gdb.write("%d <not-available>" % loc['count']) + + if loc['waste']: + gdb.write(" waste=%d/%d" % (loc['count'] * loc['waste'], loc['waste'])) + + if loc['sum_time'] != loc['min_time']: + gdb.write(" age=%d/%d/%d" % (loc['min_time'], loc['sum_time']/loc['count'], loc['max_time'])) + else: + gdb.write(" age=%d" % loc['min_time']) + + if loc['min_pid'] != loc['max_pid']: + gdb.write(" pid=%d-%d" % (loc['min_pid'], loc['max_pid'])) + else: + gdb.write(" pid=%d" % loc['min_pid']) + + if constants.LX_NR_CPUS > 1: + nr_cpu = gdb.parse_and_eval('__num_online_cpus')['counter'] + if nr_cpu > 1: + gdb.write(" cpus=") + gdb.write(','.join(str(cpu) for cpu in loc['cpus'])) + gdb.write("\n") + if constants.LX_CONFIG_STACKDEPOT: + if loc['handle']: + stackdepot.stack_depot_print(loc['handle']) + gdb.write("\n") + +def help(): + t = """Usage: lx-slabtrace --cache_name [cache_name] [Options] + Options: + --alloc + print information of allocation trace of the allocated objects + --free + print information of freeing trace of the allocated objects + Example: + lx-slabtrace --cache_name kmalloc-1k --alloc + lx-slabtrace --cache_name kmalloc-1k --free\n""" + gdb.write("Unrecognized command\n") + raise gdb.GdbError(t) + +class LxSlabTrace(gdb.Command): + """Show specific cache slabtrace""" + + def __init__(self): + super(LxSlabTrace, self).__init__("lx-slabtrace", gdb.COMMAND_DATA) + + def invoke(self, arg, from_tty): + if not constants.LX_CONFIG_SLUB_DEBUG: + raise gdb.GdbError("CONFIG_SLUB_DEBUG is not enabled") + + argv = gdb.string_to_argv(arg) + alloc = track_alloc # default show alloc_traces + + if len(argv) == 3: + if argv[2] == '--alloc': + alloc = track_alloc + elif argv[2] == '--free': + alloc = track_free + else: + help() + if len(argv) >= 2 and argv[0] == '--cache_name': + slabtrace(alloc, argv[1]) + else: + help() +LxSlabTrace() + +def slabinfo(): + nr_node_ids = None + + if not constants.LX_CONFIG_SLUB_DEBUG: + raise gdb.GdbError("CONFIG_SLUB_DEBUG is not enabled") + + def count_free(slab): + total_free = 0 + for slab in lists.list_for_each_entry(slab, slab_ptr_type, 'slab_list'): + total_free += int(slab['objects'] - slab['inuse']) + return total_free + + gdb.write("{:^18} | {:^20} | {:^12} | {:^12} | {:^8} | {:^11} | {:^13}\n".format('Pointer', 'name', 'active_objs', 'num_objs', 'objsize', 'objperslab', 'pagesperslab')) + gdb.write("{:-^18} | {:-^20} | {:-^12} | {:-^12} | {:-^8} | {:-^11} | {:-^13}\n".format('', '', '', '', '', '', '')) + + slab_caches = gdb.parse_and_eval("slab_caches") + if mm.page_ops().ops.MAX_NUMNODES > 1: + nr_node_ids = int(gdb.parse_and_eval("nr_node_ids")) + else: + nr_node_ids = 1 + + for cache in lists.list_for_each_entry(slab_caches, kmem_cache_ptr_type, 'list'): + nr_objs = 0 + nr_free = 0 + nr_slabs = 0 + for i in range(0, nr_node_ids): + cache_node = cache['node'][i] + try: + nr_slabs += cache_node['nr_slabs']['counter'] + nr_objs = int(cache_node['total_objects']['counter']) + nr_free = count_free(cache_node['partial']) + except: + raise gdb.GdbError(traceback.format_exc()) + active_objs = nr_objs - nr_free + num_objs = nr_objs + active_slabs = nr_slabs + objects_per_slab = oo_objects(cache['oo']) + cache_order = oo_order(cache['oo']) + gdb.write("{:18s} | {:20.19s} | {:12} | {:12} | {:8} | {:11} | {:13}\n".format(hex(cache), cache['name'].string(), str(active_objs), str(num_objs), str(cache['size']), str(objects_per_slab), str(1 << cache_order))) + +class LxSlabInfo(gdb.Command): + """Show slabinfo""" + + def __init__(self): + super(LxSlabInfo, self).__init__("lx-slabinfo", gdb.COMMAND_DATA) + + def invoke(self, arg, from_tty): + slabinfo() +LxSlabInfo() |