tools/lldbmacros/zonetriage.py

   1 """
   2     Triage Macros for zone related panics
   3
   4     Supported panic strings from xnu/osfmk/kern/zalloc.c:
   5         "a freed zone element has been modified in zone %s: expected %p but found %p, bits changed %p, at offset %d of %d in element %p, cookies %p %p" and
   6         "zalloc: zone map exhausted while allocating from zone %s, likely due to memory leak in zone %s (%lu total bytes, %d elements allocated)"
   7     These macros are dependant on the above panic strings. If the strings are modified in any way, this script must be updated to reflect the change.
   8
   9     To support more zone panic strings:
  10         1.  Add the panic string regex to the globals and include in the named capture group 'zone' (the zone to be
  11             logged) as well as any other info necessary to parse out of the panic string.
  12         2.  Add a check for the panic string regex in ZoneTriage(), which then calls into the function you create.
  13         3.  Add a check for the panic string regex in CheckZoneBootArgs() which sets the variable panic_string_regex to your
  14             panic string regex if found.
  15         4.  Create a function that can be called either through the zonetriage macro ZoneTriage() or using its own macro.
  16             This function should handle all lldb commands you want to run for this type of zone panic.
  17 """
  18 from xnu import *
  19 import sys, shlex
  20 from utils import *
  21 import xnudefines
  22 import re
  23 import os.path
  24
  25 ## Globals
  26 panic_string = None
  27 ## If the following panic strings are modified in xnu/osfmk/kern/zalloc.c, they must be updated here to reflect the change.
  28 zone_element_modified = ".*a freed zone element has been modified in zone (?P<zone>.+): expected (0x)?([0-9A-Fa-f]*)? but found (0x)?([0-9A-Fa-f]*)?, bits changed (0x)?([0-9A-Fa-f]*)?, at offset ([0-9]*)? of ([0-9]*)? in element (?P<element>0x[0-9A-Fa-f]*), cookies (0x)?([0-9A-Fa-f]*)? (0x)?([0-9A-Fa-f]*)?.*"
  29 zone_map_exhausted = ".*zalloc: zone map exhausted while allocating from zone .+, likely due to memory leak in zone (?P<zone>.+) \(([0-9]*)? total bytes, ([0-9]*)? elements allocated\).*"
  30
  31 # Macro: zonetriage, zonetriage_freedelement, zonetriage_memoryleak
  32 @lldb_command('zonetriage')
  33 def ZoneTriage(cmd_args=None):
  34     """ Calls function specific to type of zone panic based on the panic string
  35     """
  36     global panic_string
  37     if panic_string is None:
  38         try:
  39             panic_string = lldb_run_command("paniclog").split('\n', 1)[0]
  40         except:
  41             return
  42     if re.match(zone_element_modified, panic_string) is not None:
  43         ZoneTriageFreedElement()
  44     elif re.match(zone_map_exhausted, panic_string) is not None:
  45         ZoneTriageMemoryLeak()
  46     else:
  47         print "zonetriage does not currently support this panic string."
  48
  49 @lldb_command('zonetriage_freedelement')
  50 def ZoneTriageFreedElement(cmd_args=None):
  51     """ Runs zstack_findelem on the element and zone being logged based on the panic string regex
  52     """
  53     global panic_string
  54     if panic_string is None:
  55         try:
  56             panic_string = lldb_run_command("paniclog").split('\n', 1)[0]
  57         except:
  58             return
  59     CheckZoneBootArgs()
  60     ## Run showzonesbeinglogged.
  61     print "(lldb) zstack_showzonesbeinglogged\n%s\n" % lldb_run_command("zstack_showzonesbeinglogged")
  62     ## Capture zone and element from panic string.
  63     values = re.search(zone_element_modified, panic_string)
  64     if values is None or 'zone' not in values.group() or 'element' not in values.group():
  65         return
  66     element = values.group('element')
  67     zone = values.group('zone')
  68     btlog = FindZoneBTLog(zone)
  69     if btlog is not None:
  70         print "(lldb) zstack_findelem " + btlog + " " + element
  71         findelem_output = lldb_run_command("zstack_findelem " + btlog + " " + element)
  72         findelem_output = re.sub('Scanning is ongoing. [0-9]* items scanned since last check.\n', '', findelem_output)
  73         print findelem_output
  74
  75 @lldb_command('zonetriage_memoryleak')
  76 def ZoneTriageMemoryLeak(cmd_args=None):
  77     """ Runs zstack_findtop and zstack_findleak on all zones being logged
  78     """
  79     global kern
  80     CheckZoneBootArgs()
  81     ## Run showzonesbeinglogged.
  82     print "(lldb) zstack_showzonesbeinglogged\n%s\n" % lldb_run_command("zstack_showzonesbeinglogged")
  83     for zval in kern.zones:
  84         if zval.zlog_btlog:
  85             print '%s:' % zval.z_name
  86             print "(lldb) zstack_findtop -N 5 0x%lx" % zval.zlog_btlog
  87             print lldb_run_command("zstack_findtop -N 5 0x%lx" % zval.zlog_btlog)
  88             print "(lldb) zstack_findleak 0x%lx" % zval.zlog_btlog
  89             print lldb_run_command("zstack_findleak 0x%lx" % zval.zlog_btlog)
  90
  91 def CheckZoneBootArgs(cmd_args=None):
  92     """ Check boot args to see if zone is being logged, if not, suggest new boot args
  93     """
  94     global panic_string
  95     if panic_string is None:
  96         try:
  97             panic_string = lldb_run_command("paniclog").split('\n', 1)[0]
  98         except:
  99             return
 100     panic_string_regex = ""
 101     if re.match(zone_element_modified, panic_string) is not None:
 102         panic_string_regex = zone_element_modified
 103     if re.match(zone_map_exhausted, panic_string) is not None:
 104         panic_string_regex = zone_map_exhausted
 105     values = re.search(panic_string_regex, panic_string)
 106     if values is None or 'zone' not in values.group():
 107         return
 108     zone = values.group('zone')
 109     bootargs = lldb_run_command("showbootargs")
 110     correct_boot_args = re.search('zlog([1-9]|10)?=' + re.sub(' ', '.', zone), bootargs)
 111     if correct_boot_args is None:
 112         print "Current boot-args:\n" + bootargs
 113         print "You may need to include: -zc -zp zlog([1-9]|10)?=" + re.sub(' ', '.', zone)
 114
 115 def FindZoneBTLog(zone):
 116     """ Returns the btlog address in the format 0x%lx for the zone name passed as a parameter
 117     """
 118     global kern
 119     for zval in kern.zones:
 120         if zval.zlog_btlog:
 121             if zone == "%s" % zval.z_name:
 122                 return "0x%lx" % zval.zlog_btlog
 123     return None
 124 # EndMacro: zonetriage, zonetriage_freedelement, zonetriage_memoryleak