# SPDX-License-Identifier: GPL-2.0
#
# Copyright (c) 2023 MediaTek Inc.
#
# Authors:
# Kuan-Ying Lee <[email protected]>
#
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()
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