SIGSEGV during GC

SIGSEGV during GC

[David Ponce]

Hi,

Since I enabled USE_LSB_TAG, Emacs sometimes crashes after a variable
period of intensive use.

I managed to get the trace that follows.  It looks like the crash
occured during GC.

Hope it will help.

Sincerely,
David

Here is my environment:

GNU/Linux Fedora Core 1
gcc (GCC) 3.3.2 20031022 (Red Hat Linux 3.3.2-1)

In GNU Emacs 21.3.50.6 (i686-pc-linux-gnu, GTK+ Version 2.2.4)
  of 2004-01-23 on maunakea
configured using `configure '--prefix=/home/ponce' '--with-x-toolkit=gtk''

Important settings:
   value of $LC_ALL: nil
   value of $LC_COLLATE: nil
   value of $LC_CTYPE: nil
   value of $LC_MESSAGES: nil
   value of $LC_MONETARY: nil
   value of $LC_NUMERIC: nil
   value of $LC_TIME: nil
   value of $LANG: en_US.UTF-8
   locale-coding-system: utf-8
   default-enable-multibyte-characters: t

Here is the gdb trace:

(gdb) run
Starting program: /home/ponce/installs/emacs/src/emacs

Program received signal SIGSEGV, Segmentation fault.
mark_object (arg=1) at alloc.c:4952
4952            if (ptr->gcmarkbit) break;
(gdb) bt
#0  mark_object (arg=1) at alloc.c:4952
#1  0x0811f44b in mark_kboards () at keyboard.c:11316
#2  0x08159553 in Fgarbage_collect () at alloc.c:4464
#3  0x0816cb2a in Feval (form=138077696) at eval.c:2077
#4  0x0816a503 in Fprogn (args=114) at eval.c:408
#5  0x0816afc9 in FletX (args=161623925) at eval.c:878
#6  0x0816cc89 in Feval (form=138082284) at eval.c:2027
#7  0x0816a3b7 in Fand (args=114) at eval.c:329
#8  0x0816cc89 in Feval (form=138081900) at eval.c:2027
#9  0x0816a503 in Fprogn (args=114) at eval.c:408
#10 0x0816d845 in funcall_lambda (fun=161622416, nargs=1, arg_vector=0xbff9fbb0) at eval.c:2908
#11 0x0816d687 in apply_lambda (fun=161622421, args=138358553, eval_flag=1) at eval.c:2837
#12 0x0816c9bc in Feval (form=161622421) at eval.c:2138
#13 0x0816a503 in Fprogn (args=114) at eval.c:408
#14 0x0816d845 in funcall_lambda (fun=160720448, nargs=0, arg_vector=0xbff9fd60) at eval.c:2908
#15 0x0816d687 in apply_lambda (fun=160720453, args=138358505, eval_flag=1) at eval.c:2837
#16 0x0816c9bc in Feval (form=160720453) at eval.c:2138
#17 0x0816a503 in Fprogn (args=114) at eval.c:408
#18 0x0816cc89 in Feval (form=138081972) at eval.c:2027
#19 0x0816b89f in Fcondition_case (args=138358505) at eval.c:1280
#20 0x0816cc89 in Feval (form=138082452) at eval.c:2027
#21 0x0816a503 in Fprogn (args=114) at eval.c:408
#22 0x0816a441 in Fif (args=161058853) at eval.c:357
#23 0x0816cc89 in Feval (form=138081924) at eval.c:2027
#24 0x0816a420 in Fif (args=161058949) at eval.c:356
#25 0x0816cc89 in Feval (form=138081924) at eval.c:2027
#26 0x0816a503 in Fprogn (args=114) at eval.c:408
#27 0x0816d845 in funcall_lambda (fun=161057904, nargs=0, arg_vector=0xbffa03f0) at eval.c:2908
#28 0x0816d687 in apply_lambda (fun=161057909, args=138358505, eval_flag=1) at eval.c:2837
#29 0x0816c9bc in Feval (form=161057909) at eval.c:2138
#30 0x0816a503 in Fprogn (args=114) at eval.c:408
#31 0x0816d845 in funcall_lambda (fun=161057360, nargs=0, arg_vector=0xbffa066c) at eval.c:2908
#32 0x0816d3f7 in Ffuncall (nargs=1, args=0xbffa0668) at eval.c:2785
#33 0x0816d024 in run_hook_with_args (nargs=1, args=0xbffa0668, cond=to_completion) at eval.c:2396
#34 0x0816ced5 in Frun_hooks (nargs=1, args=0xbffa0690) at eval.c:2264
#35 0x0816cb40 in Feval (form=138082592) at eval.c:2080
#36 0x0816a503 in Fprogn (args=114) at eval.c:408
#37 0x0816cc89 in Feval (form=138081972) at eval.c:2027
#38 0x0816a420 in Fif (args=182888797) at eval.c:356
---Type <return> to continue, or q <return> to quit---
#39 0x0816cc89 in Feval (form=138081924) at eval.c:2027
#40 0x0816ca29 in Feval (form=138379821) at eval.c:2136
#41 0x0816a503 in Fprogn (args=114) at eval.c:408
#42 0x0816d845 in funcall_lambda (fun=161579976, nargs=0, arg_vector=0xbffa0a70) at eval.c:2908
#43 0x0816d687 in apply_lambda (fun=161579981, args=138358505, eval_flag=1) at eval.c:2837
#44 0x0816c9bc in Feval (form=161579981) at eval.c:2138
#45 0x0816a503 in Fprogn (args=114) at eval.c:408
#46 0x081631ce in Fsave_current_buffer (args=182889045) at editfns.c:966
#47 0x0816cc89 in Feval (form=138080388) at eval.c:2027
#48 0x0816ca29 in Feval (form=138627005) at eval.c:2136
#49 0x0816a3b7 in Fand (args=114) at eval.c:329
#50 0x0816cc89 in Feval (form=138081900) at eval.c:2027
#51 0x0816a503 in Fprogn (args=114) at eval.c:408
#52 0x0816b2a6 in Fwhile (args=161578245) at eval.c:958
#53 0x0816cc89 in Feval (form=138082332) at eval.c:2027
#54 0x0816a503 in Fprogn (args=114) at eval.c:408
#55 0x0816b1d0 in Flet (args=161578149) at eval.c:936
#56 0x0816cc89 in Feval (form=138082308) at eval.c:2027
#57 0x0816a503 in Fprogn (args=114) at eval.c:408
#58 0x0816d845 in funcall_lambda (fun=161578368, nargs=0, arg_vector=0xbffa123c) at eval.c:2908
#59 0x0816d3f7 in Ffuncall (nargs=1, args=0xbffa1238) at eval.c:2785
#60 0x0816d024 in run_hook_with_args (nargs=1, args=0xbffa1238, cond=to_completion) at eval.c:2396
#61 0x0816ced5 in Frun_hooks (nargs=1, args=0xbffa12c4) at eval.c:2264
#62 0x0816d5ca in Ffuncall (nargs=2, args=0xbffa12c0) at eval.c:2709
#63 0x08195d43 in Fbyte_code (bytestr=138419801, vector=1, maxdepth=-1074130240) at bytecode.c:689
#64 0x0816d80b in funcall_lambda (fun=136326588, nargs=2, arg_vector=0xbffa13e4) at eval.c:2915
#65 0x0816d3f7 in Ffuncall (nargs=3, args=0xbffa13e0) at eval.c:2785
#66 0x08195d43 in Fbyte_code (bytestr=138615401, vector=2, maxdepth=-1074129952) at bytecode.c:689
#67 0x0816d80b in funcall_lambda (fun=136323900, nargs=6, arg_vector=0xbffa14f4) at eval.c:2915
#68 0x0816d3f7 in Ffuncall (nargs=7, args=0xbffa14f0) at eval.c:2785
#69 0x08195d43 in Fbyte_code (bytestr=138733201, vector=6, maxdepth=-1074129680) at bytecode.c:689
#70 0x0816d80b in funcall_lambda (fun=136321444, nargs=4, arg_vector=0xbffa1614) at eval.c:2915
#71 0x0816d3f7 in Ffuncall (nargs=5, args=0xbffa1610) at eval.c:2785
#72 0x08195d43 in Fbyte_code (bytestr=138768009, vector=4, maxdepth=-1074129392) at bytecode.c:689
#73 0x0816d80b in funcall_lambda (fun=136315612, nargs=1, arg_vector=0xbffa16d0) at eval.c:2915
#74 0x0816d687 in apply_lambda (fun=136315612, args=166747099, eval_flag=1) at eval.c:2837
#75 0x0816c9bc in Feval (form=136315612) at eval.c:2138
#76 0x0816a503 in Fprogn (args=114) at eval.c:408
#77 0x0816a441 in Fif (args=160175557) at eval.c:357
---Type <return> to continue, or q <return> to quit---
#78 0x0816cc89 in Feval (form=138081924) at eval.c:2027
#79 0x0816a503 in Fprogn (args=114) at eval.c:408
#80 0x0816d845 in funcall_lambda (fun=160175360, nargs=1, arg_vector=0xbffa19a0) at eval.c:2908
#81 0x0816d687 in apply_lambda (fun=160175365, args=166747099, eval_flag=1) at eval.c:2837
#82 0x0816c9bc in Feval (form=160175365) at eval.c:2138
#83 0x0816a503 in Fprogn (args=114) at eval.c:408
#84 0x0816d845 in funcall_lambda (fun=184772216, nargs=0, arg_vector=0xbffa1bd4) at eval.c:2908
#85 0x0816d3f7 in Ffuncall (nargs=1, args=0xbffa1bd0) at eval.c:2785
#86 0x0816d1f2 in apply1 (fn=171579657, arg=114) at eval.c:2478
#87 0x08169cf8 in Fcall_interactively (function=171579657, record_flag=17294813, keys=182447796) at callint.c:414
#88 0x0811ce5f in Fcommand_execute (cmd=171579657, record_flag=138358505, keys=138358505, special=1) at keyboard.c:9627
#89 0x08112187 in command_loop_1 () at keyboard.c:1727
#90 0x0816b9a2 in internal_condition_case (bfun=0x8111dd0 <command_loop_1>, handlers=138419393, hfun=0x8111998 <cmd_error>)
     at eval.c:1333
#91 0x08111c8e in command_loop_2 () at keyboard.c:1264
#92 0x0816b515 in internal_catch (tag=1, func=0x8111c70 <command_loop_2>, arg=138358505) at eval.c:1094
#93 0x08111c44 in command_loop () at keyboard.c:1243
#94 0x08111774 in recursive_edit_1 () at keyboard.c:959
#95 0x08111880 in Frecursive_edit () at keyboard.c:1015
#96 0x081101dd in main (argc=1, argv=0xbffa23b4) at emacs.c:1666

Re: SIGSEGV during GC

[Stefan Monnier]

> Since I enabled USE_LSB_TAG, Emacs sometimes crashes after a variable
> period of intensive use.

I installed another change at around the same time that had to do with
mark_kboards, so maybe it's unrelated to USE_LSB_TAG.  I'll investigate
on my side, but could you try and see if the bug also shows up if you don't
USE_LSB_TAG ?


        Stefan

Re: SIGSEGV during GC

[David Ponce]

Hi Stefan,

 >>Since I enabled USE_LSB_TAG, Emacs sometimes crashes after a variable
 >>period of intensive use.
 >
 >
 > I installed another change at around the same time that had to do with
 > mark_kboards, so maybe it's unrelated to USE_LSB_TAG.  I'll investigate
 > on my side, but could you try and see if the bug also shows up if you don't
 > USE_LSB_TAG ?

Since your advice, I used (daily) a version of CVS GNU Emacs built without
USE_LSB_TAG enabled, and didn't experienced any crash.

So today I rebuilt Emacs with USE_LSB_TAG enabled, and after a short
period of use it crashed (SIGSEGV) during GC.

Following is the gdb backtrace I got.  My environment is:

GNU/Linux Fedora Core 1
gcc (GCC) 3.3.2 20031022 (Red Hat Linux 3.3.2-1)

In GNU Emacs 21.3.50.1 (i686-pc-linux-gnu, GTK+ Version 2.2.4)
  of 2004-02-01 on maunakea
configured using `configure '--prefix=/home/ponce' '--with-x-toolkit=gtk''

Important settings:
   value of $LC_ALL: nil
   value of $LC_COLLATE: nil
   value of $LC_CTYPE: nil
   value of $LC_MESSAGES: nil
   value of $LC_MONETARY: nil
   value of $LC_NUMERIC: nil
   value of $LC_TIME: nil
   value of $LANG: en_US.UTF-8
   locale-coding-system: utf-8
   default-enable-multibyte-characters: t

Hope this will help.

David


Starting program: /home/ponce/installs/emacs/src/emacs

Program received signal SIGSEGV, Segmentation fault.
0x0815a058 in mark_object (arg=0) at alloc.c:5040
5040            if (CONS_MARKED_P (ptr)) break;
(gdb) bt
#0  0x0815a058 in mark_object (arg=0) at alloc.c:5040
#1  0x0811f477 in mark_kboards () at keyboard.c:11316
#2  0x08159563 in Fgarbage_collect () at alloc.c:4465
#3  0x0816cb82 in Feval (form=138077792) at eval.c:2077
#4  0x0816a55b in Fprogn (args=470) at eval.c:408
#5  0x0816b021 in FletX (args=165065613) at eval.c:878
#6  0x0816cce1 in Feval (form=138082380) at eval.c:2027
#7  0x0816a55b in Fprogn (args=470) at eval.c:408
#8  0x0816b021 in FletX (args=165224941) at eval.c:878
#9  0x0816cce1 in Feval (form=138082380) at eval.c:2027
#10 0x0816ca81 in Feval (form=164733237) at eval.c:2136
#11 0x0816a55b in Fprogn (args=470) at eval.c:408
#12 0x0816a499 in Fif (args=165065501) at eval.c:357
#13 0x0816cce1 in Feval (form=138082020) at eval.c:2027
#14 0x0816a55b in Fprogn (args=470) at eval.c:408
#15 0x0816d89d in funcall_lambda (fun=165063800, nargs=2,
     arg_vector=0xbff01850) at eval.c:2908
#16 0x0816d6df in apply_lambda (fun=165063805, args=164739021,
     eval_flag=1) at eval.c:2837
#17 0x0816ca14 in Feval (form=165063805) at eval.c:2138
#18 0x0816a55b in Fprogn (args=470) at eval.c:408
#19 0x0816cce1 in Feval (form=138082068) at eval.c:2027
#20 0x0816ad6b in Fdefconst (args=164696333) at eval.c:795
#21 0x0816cce1 in Feval (form=138082332) at eval.c:2027
#22 0x081808b3 in readevalloop (readcharfun=164668188, stream=0x0,
     sourcename=164692827, evalfun=0x816c864 <Feval>, printflag=0,
     unibyte=138358609, readfun=138358609) at lread.c:1376
#23 0x08180b42 in Feval_buffer (buffer=44, printflag=17294826,
     filename=164692827, unibyte=138358609, do_allow_print=135671776)
     at lread.c:1434
#24 0x0816d5a7 in Ffuncall (nargs=6, args=0xbff01c64) at eval.c:2744
#25 0x08195daf in Fbyte_code (bytestr=138651209, vector=5,
     maxdepth=-1074783136) at bytecode.c:689
#26 0x0816d863 in funcall_lambda (fun=136234364, nargs=4,
     arg_vector=0xbff01da4) at eval.c:2915
#27 0x0816d44f in Ffuncall (nargs=5, args=0xbff01da0) at eval.c:2785
#28 0x0816d2cc in call4 (fn=138746265, arg1=164667763, arg2=164692827,
     arg3=138358609, arg4=138358657) at eval.c:2591
#29 0x0817fbfa in Fload (file=164692827, noerror=17294826,
     nomessage=17294832, nosuffix=0, must_suffix=17294832) at
     lread.c:864
#30 0x08176837 in Frequire (feature=164664001, filename=138358609,
     noerror=138358609) at fns.c:3408
#31 0x0816cb98 in Feval (form=138084944) at eval.c:2080
#32 0x081808b3 in readevalloop (readcharfun=164546852, stream=0x0,
     sourcename=164531763, evalfun=0x816c864 <Feval>, printflag=0,
     unibyte=138358609, readfun=138358609) at lread.c:1376
#33 0x08180b42 in Feval_buffer (buffer=44, printflag=17294826,
     filename=164531763, unibyte=138358609, do_allow_print=135671776)
     at lread.c:1434
#34 0x0816d5a7 in Ffuncall (nargs=6, args=0xbff02124) at eval.c:2744
---Type <return> to continue, or q <return> to quit---
#35 0x08195daf in Fbyte_code (bytestr=138651209, vector=5,
     maxdepth=-1074781920) at bytecode.c:689
#36 0x0816d863 in funcall_lambda (fun=136234364, nargs=4,
     arg_vector=0xbff02264) at eval.c:2915
#37 0x0816d44f in Ffuncall (nargs=5, args=0xbff02260) at eval.c:2785
#38 0x0816d2cc in call4 (fn=138746265, arg1=164546155, arg2=164531763,
     arg3=138358609, arg4=138358657) at eval.c:2591
#39 0x0817fbfa in Fload (file=164531763, noerror=17294826,
     nomessage=17294832, nosuffix=0, must_suffix=17294832) at
     lread.c:864
#40 0x08176837 in Frequire (feature=162804329, filename=138358609,
     noerror=138358609) at fns.c:3408
#41 0x0816cb98 in Feval (form=138084944) at eval.c:2080
#42 0x081808b3 in readevalloop (readcharfun=164503060, stream=0x0,
     sourcename=159173547, evalfun=0x816c864 <Feval>, printflag=0,
     unibyte=138358609, readfun=138358609) at lread.c:1376
#43 0x08180b42 in Feval_buffer (buffer=44, printflag=17294826,
     filename=159173547, unibyte=138358609, do_allow_print=135671776)
     at lread.c:1434
#44 0x0816d5a7 in Ffuncall (nargs=6, args=0xbff025e4) at eval.c:2744
#45 0x08195daf in Fbyte_code (bytestr=138651209, vector=5,
     maxdepth=-1074780704) at bytecode.c:689
#46 0x0816d863 in funcall_lambda (fun=136234364, nargs=4,
     arg_vector=0xbff02724) at eval.c:2915
#47 0x0816d44f in Ffuncall (nargs=5, args=0xbff02720) at eval.c:2785
#48 0x0816d2cc in call4 (fn=138746265, arg1=164531379, arg2=159173547,
     arg3=138358609, arg4=138358609) at eval.c:2591
#49 0x0817fbfa in Fload (file=159173547, noerror=17294826,
     nomessage=17294826, nosuffix=0, must_suffix=17294832) at
     lread.c:864
#50 0x0816c774 in do_autoload (fundef=159156061, funname=159164281) at
     eval.c:1925
#51 0x0816d41a in Ffuncall (nargs=1, args=0xbff02950) at eval.c:2788
#52 0x08195daf in Fbyte_code (bytestr=138668673, vector=0,
     maxdepth=-1074779824) at bytecode.c:689
#53 0x0816d863 in funcall_lambda (fun=136334804, nargs=0,
     arg_vector=0xbff02a00) at eval.c:2915
#54 0x0816d6df in apply_lambda (fun=136334804, args=138358609,
     eval_flag=1) at eval.c:2837
#55 0x0816ca14 in Feval (form=136334804) at eval.c:2138
#56 0x0816b8f7 in Fcondition_case (args=138358609) at eval.c:1280
#57 0x08196e15 in Fbyte_code (bytestr=138442825, vector=143,
     maxdepth=-1074779040) at bytecode.c:870
#58 0x0816d863 in funcall_lambda (fun=136327900, nargs=1,
     arg_vector=0xbff02d74) at eval.c:2915
#59 0x0816d44f in Ffuncall (nargs=2, args=0xbff02d70) at eval.c:2785
#60 0x08195daf in Fbyte_code (bytestr=138729353, vector=1, maxdepth=-1074778768) at bytecode.c:689
#61 0x0816d863 in funcall_lambda (fun=136326684, nargs=2,
     arg_vector=0xbff02e94) at eval.c:2915
#62 0x0816d44f in Ffuncall (nargs=3, args=0xbff02e90) at eval.c:2785
#63 0x08195daf in Fbyte_code (bytestr=138616753, vector=2,
     maxdepth=-1074778480) at bytecode.c:689
#64 0x0816d863 in funcall_lambda (fun=136323996, nargs=6,
     arg_vector=0xbff02fa4) at eval.c:2915
#65 0x0816d44f in Ffuncall (nargs=7, args=0xbff02fa0) at eval.c:2785
#66 0x08195daf in Fbyte_code (bytestr=138733297, vector=6,
     maxdepth=-1074778208) at bytecode.c:689
#67 0x0816d863 in funcall_lambda (fun=136321540, nargs=4,
     arg_vector=0xbff030c4) at eval.c:2915
#68 0x0816d44f in Ffuncall (nargs=5, args=0xbff030c0) at eval.c:2785
#69 0x08195daf in Fbyte_code (bytestr=138615953, vector=4,
     maxdepth=-1074777920) at bytecode.c:689
#70 0x0816d863 in funcall_lambda (fun=136315708, nargs=1,
     arg_vector=0xbff03180) at eval.c:2915
#71 0x0816d6df in apply_lambda (fun=136315708, args=159134579,
     eval_flag=1) at eval.c:2837
---Type <return> to continue, or q <return> to quit---
#72 0x0816ca14 in Feval (form=136315708) at eval.c:2138
#73 0x0816a55b in Fprogn (args=470) at eval.c:408
#74 0x0816a499 in Fif (args=159240589) at eval.c:357
#75 0x0816cce1 in Feval (form=138082020) at eval.c:2027
#76 0x0816a55b in Fprogn (args=470) at eval.c:408
#77 0x0816d89d in funcall_lambda (fun=159240464, nargs=1,
     arg_vector=0xbff03450) at eval.c:2908
#78 0x0816d6df in apply_lambda (fun=159240469, args=159134579,
     eval_flag=1) at eval.c:2837
#79 0x0816ca14 in Feval (form=159240469) at eval.c:2138
#80 0x0816a55b in Fprogn (args=470) at eval.c:408
#81 0x0816d89d in funcall_lambda (fun=161076240, nargs=0,
     arg_vector=0xbff03684) at eval.c:2908
#82 0x0816d44f in Ffuncall (nargs=1, args=0xbff03680) at eval.c:2785
#83 0x0816d24a in apply1 (fn=162739689, arg=470) at eval.c:2478
#84 0x08169d50 in Fcall_interactively (function=162739689,
     record_flag=17294826, keys=138415468) at callint.c:414
#85 0x0811ce8b in Fcommand_execute (cmd=162739689,
     record_flag=138358609, keys=138358609, special=0) at
     keyboard.c:9627
#86 0x081121b3 in command_loop_1 () at keyboard.c:1727
#87 0x0816b9fa in internal_condition_case (bfun=0x8111dfc
     <command_loop_1>, handlers=138419489, hfun=0x81119c4 <cmd_error>)
     at eval.c:1333
#88 0x08111cba in command_loop_2 () at keyboard.c:1264
#89 0x0816b56d in internal_catch (tag=0, func=0x8111c9c
     <command_loop_2>, arg=138358609) at eval.c:1094
#90 0x08111c70 in command_loop () at keyboard.c:1243
#91 0x081117a0 in recursive_edit_1 () at keyboard.c:959
#92 0x081118ac in Frecursive_edit () at keyboard.c:1015
#93 0x08110209 in main (argc=1, argv=0xbff03e64) at emacs.c:1666

Re: SIGSEGV during GC

[Stefan Monnier]

> Since I enabled USE_LSB_TAG, Emacs sometimes crashes after a variable
> period of intensive use.

> I managed to get the trace that follows.  It looks like the crash
> occured during GC.

I still haven't been able to track it down and the manual sanity checking
didn't turn up anything either.  Do you have any news on your side about the
above problem?  Which part of the backtrace is always the same?


        Stefan