# SEGV: def m() yield \[\] end; m(&lambda {|\*v| p v})

**URL:** <https://www.ruby-forum.com/t/segv-def-m-yield-end-m-lambda-v-p-v/112422>\
**Category:** Development\
**Created:** [August 18, 2007, 6:04pm UTC](https://www.ruby-forum.com/t/segv-def-m-yield-end-m-lambda-v-p-v/112422 "2007-08-18T18:04:38Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![Tanaka\_A](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/c67d28/32.png) [@Tanaka\_A](https://www.ruby-forum.com/u/Tanaka_A)\
**Post date:** [August 18, 2007, 6:04pm UTC](https://www.ruby-forum.com/t/segv-def-m-yield-end-m-lambda-v-p-v/112422/1 "2007-08-18T18:04:38Z")

</div>

e$B0J2\<$N$h$&$K$9$k$He(B SEGV e$B$K$J$j$^$9!#e(B

## % RUBY\_DEBUG=gc\_stress ./ruby -e ‘def m() yield [] end; m(&lambda {|\*v| p v})’ -e:1: – control frame ---------- c:0007 p:---- s:0016 b:0016 l:000015 d:000015 CFUNC :inspect c:0006 p:---- s:0014 b:0014 l:000013 d:000013 CFUNC 😛 c:0005 p:0010 s:0010 b:0010 l:000e6c d:000009 BLOCK -e:1 c:0004 p:0005 s:0008 b:0008 l:000007 d:000007 METHOD -e:1 c:0003 p:0019 s:0005 b:0005 l:000e6c d:000e6c TOP -e:1 c:0002 p:---- s:0003 b:0003 l:000002 d:000002 FINISH :inherited c:0001 p:---- s:0001 b:-001 l:000000 d:000000 ------

## DBG\> : “-e:1:in `p'" DBG> : "-e:1:in`block in '” DBG\> : “-e:1:in `m'" DBG> : "-e:1:in`'” – backtrace of native function call (Use addr2line) – 0x80db025 0x80f45e3 0x80f46ab 0x80b21f0 0xb7f8f420 0x80576e4 0x8057733 0x8059c07 0x805a156 0x8076786 0x80e2631 0x80ded7b 0x80e2596 0x80d9ee1 0x8059c68 0x805a156 0x8076786 0x8064001 0x806b81c 0x80d182e 0x80d34b4 0x80d6193 0x80d98e4 0x80d9c1b 0x8059339 0x805c93d 0x8056f76 0xb7df8ea8 0x8056e91

[BUG] Segmentation fault  
ruby 1.9.0 (2007-08-18) [i686-linux]

% RUBY\_DEBUG=gc\_stress,core ./ruby -e ‘def m() yield [] end; m(&lambda  
{|\*v| p v})’  
zsh: segmentation fault (core dumped) RUBY\_DEBUG=gc\_stress,core ./ruby  
-e  
% gdb ruby core.27446  
GNU gdb 6.4.90-debian  
Copyright © 2006 Free Software Foundation, Inc.  
GDB is free software, covered by the GNU General Public License, and you  
are  
welcome to change it and/or distribute copies of it under certain  
conditions.  
Type “show copying” to see the conditions.  
There is absolutely no warranty for GDB. Type “show warranty” for  
details.  
This GDB was configured as “i486-linux-gnu”…Using host libthread\_db  
library “/lib/tls/libthread\_db.so.1”.

warning: Can’t read pathname for load map: Input/output error.  
Reading symbols from /lib/tls/libpthread.so.0…done.  
Loaded symbols for /lib/tls/libpthread.so.0  
Reading symbols from /lib/tls/libdl.so.2…done.  
Loaded symbols for /lib/tls/libdl.so.2  
Reading symbols from /lib/tls/libcrypt.so.1…done.  
Loaded symbols for /lib/tls/libcrypt.so.1  
Reading symbols from /lib/tls/libm.so.6…done.  
Loaded symbols for /lib/tls/libm.so.6  
Reading symbols from /lib/tls/libc.so.6…done.  
Loaded symbols for /lib/tls/libc.so.6  
Reading symbols from /lib/ld-linux.so.2…done.  
Loaded symbols for /lib/ld-linux.so.2  
Core was generated by `./ruby -e def m() yield [] end; m(&lambda {|\*v| p  
v})’.  
Program terminated with signal 11, Segmentation fault.  
#0 st\_lookup (table=0x0, key=800, value=0xbfd32c18) at st.c:245  
245 hash\_val = do\_hash(key, table);  
(gdb) bt  
#0 st\_lookup (table=0x0, key=800, value=0xbfd32c18) at st.c:245  
#1 0x080576e4 in search\_method (klass=3084384680, id=800, klassp=0x0)  
at eval\_method.ci:204  
#2 0x08057733 in rb\_get\_method\_body (klass=3084384680, id=800,  
idp=0xbfd32ca8) at eval\_method.ci:231  
#3 0x08059c07 in rb\_call (klass=3084384680, recv=3084384700, mid=0,  
argc=0, argv=0x0, scope=3) at eval.c:1365  
#4 0x0805a156 in rb\_funcall (recv=, mid=800, n=0)  
at eval.c:1524  
#5 0x08076786 in rb\_inspect (obj=3084384700) at object.c:263  
#6 0x080e2631 in inspect\_ary (ary=3084388200, dummy=0, recur=0) at  
array.c:1351  
#7 0x080ded7b in rb\_exec\_recursive (func=0x80e25b0 \<inspect\_ary\>,  
obj=3084388200, arg=0) at thread.c:2564  
#8 0x080e2596 in rb\_ary\_inspect (ary=0) at array.c:1373  
#9 0x080d9ee1 in vm\_call0 (th=0x8157160, klass=3084547620,  
recv=3084388200, id=800, oid=0, argc=0, argv=0x0,  
body=0xb7da74bc, nosuper=0) at vm.c:453  
#10 0x08059c68 in rb\_call (klass=3084547620, recv=3084388200, mid=800,  
argc=0, argv=0x0, scope=3) at eval.c:1416  
#11 0x0805a156 in rb\_funcall (recv=, mid=800, n=0)  
at eval.c:1524  
#12 0x08076786 in rb\_inspect (obj=3084388200) at object.c:263  
#13 0x08064001 in rb\_p (obj=3084388200) at io.c:3966  
#14 0x0806b81c in rb\_f\_p (argc=1, argv=0xb7db4034, self=3084588640) at  
io.c:3994  
#15 0x080d182e in call\_cfunc (func=0x806b7f0 \<rb\_f\_p\>, recv=3084588640,  
len=0, argc=0, argv=0xb7db4034) at insnhelper.ci:277  
#16 0x080d34b4 in vm\_call\_method (th=0x8157160, cfp=0xb7e33ef0, num=1,  
blockptr=0x1, flag=8, id=5048, mn=0xb7da2c50,  
recv=3084588640, klass=3084588620) at insnhelper.ci:366  
#17 0x080d6193 in vm\_eval (th=0x8157160, initial=0) at insns.def:1113  
#18 0x080d98e4 in vm\_eval\_body (th=0x8157160) at vm.c:1170  
#19 0x080d9c1b in rb\_iseq\_eval (iseqval=3084384980) at vm.c:1379  
#20 0x08059339 in ruby\_exec\_node (n=0xb7d7fb10, file=0x818b8a9 “-e”) at  
eval.c:231  
#21 0x0805c93d in ruby\_run\_node (n=0xb7d7fb10) at eval.c:256  
#22 0x08056f76 in main (argc=Cannot access memory at address 0x0  
) at main.c:46  
(gdb)

---

<div class="post-metadata">

**Author:** ![Tanaka\_A](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/c67d28/32.png) [@Tanaka\_A](https://www.ruby-forum.com/u/Tanaka_A)\
**Post date:** [August 18, 2007, 7:17pm UTC](https://www.ruby-forum.com/t/segv-def-m-yield-end-m-lambda-v-p-v/112422/2 "2007-08-18T19:17:42Z")

</div>

In article [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid),  
Tanaka A. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) writes:

> e$B0J2\<$N$h$&$K$9$k$He(B SEGV e$B$K$J$j$^$9!#e(B

yield e$BD\>A0$Ge(B GC.stress = true  
e$B$9$l$PJQ$J$3$H$,5/$-$k$h$&$G$9!#e(B

% ./ruby -e ‘def m() GC.stress = true; yield [] end; m(&lambda {|\*v| p  
v})’  
[[…]]

yield e$B$N0z?t$Ne(B []  
e$B$rJQ?t$KBeF~$7$F$\*$/$HLdBj$,H/@8$7$J$$$N$G!"e(B  
e$B$3$l$,\>C$($F$k$N$+$J$!!#e(B

% ./ruby -e ‘def m() GC.stress = true; yield a=[] end; m(&lambda {|\*v| p  
v})’  
[[]]

% ./ruby -v  
ruby 1.9.0 (2007-08-18 patchlevel 0) [i686-linux]

---

<div class="post-metadata">

**Author:** ![Tanaka\_A](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/c67d28/32.png) [@Tanaka\_A](https://www.ruby-forum.com/u/Tanaka_A)\
**Post date:** [August 19, 2007, 5:01am UTC](https://www.ruby-forum.com/t/segv-def-m-yield-end-m-lambda-v-p-v/112422/3 "2007-08-19T05:01:29Z")

</div>

e$B!!$5$5$@$G$9!#e(B

Tanaka A. wrote:

> e$B0J2\<$N$h$&$K$9$k$He(B SEGV e$B$K$J$j$^$9!#e(B
> 
> % RUBY\_DEBUG=gc\_stress ./ruby -e ‘def m() yield [] end; m(&lambda {|\*v| p v})’

e$B!!$&$A$@$He(B SEGV e$B$7$J$+$C$?$s$G$9$,!"$3$l$Ge(B SEGV  
e$B$7$J$/$J$k$+!";n$7$Fe(B  
e$B$b$i$($J$$$G$7$g$&$+!#e(B

# Index: insnhelper.ci

— insnhelper.ci (e$B%j%S%8%g%se(B 13107)  
+++ insnhelper.ci (e$B:n6H%3%T!\<e(B)  
@@ -114,6 +114,7 @@  
else {  
VALUE \* const dst = argv;  
int opt\_pc = 0;

- th-\>mark\_stack\_len = iseq-\>arg\_size;

- 

```
   th->mark_stack_len = orig_argc; /* for GC */
   blockval = vm_make_proc(th, th->cfp, blockptr);

```

- 

```
   th->mark_stack_len = 0;

   GetProcPtr(blockval, proc);
   *block = &proc->block;

```

@@ -190,7 +189,7 @@

```
   dst[iseq->arg_block] = blockval; /* Proc or nil */

```

## }

- th-\>mark\_stack\_len = 0;  
return opt\_pc;  
}  
}

---

<div class="post-metadata">

**Author:** ![Tanaka\_A](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/c67d28/32.png) [@Tanaka\_A](https://www.ruby-forum.com/u/Tanaka_A)\
**Post date:** [August 19, 2007, 5:05am UTC](https://www.ruby-forum.com/t/segv-def-m-yield-end-m-lambda-v-p-v/112422/4 "2007-08-19T05:05:29Z")

</div>

In article [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid),  
SASADA Koichi [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) writes:

> e$B!!$&$A$@$He(B SEGV e$B$7$J$+$C$?$s$G$9$,!“$3$l$Ge(B SEGV e$B$7$J$/$J$k$+!”;n$7$Fe(B  
> e$B$b$i$($J$$$G$7$g$&$+!#e(B

e$B\>I\>u$,$\*$5$^$j$^$9!#e(B