# \[Bug:1.9\] SEGV by File.foreach("keywords")

**URL:** <https://www.ruby-forum.com/t/bug-1-9-segv-by-file-foreach-keywords/139819>\
**Category:** Development\
**Created:** [June 7, 2008, 5:29pm UTC](https://www.ruby-forum.com/t/bug-1-9-segv-by-file-foreach-keywords/139819 "2008-06-07T17:29:45Z")\
**Posts on this page:** 2\
**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:** [June 7, 2008, 5:29pm UTC](https://www.ruby-forum.com/t/bug-1-9-segv-by-file-foreach-keywords/139819/1 "2008-06-07T17:29:45Z")

</div>

e$B0J2\<$N$h$&$K$9$k$He(B SEGV e$B$7$^$9!#e(B

% ./ruby -ve ’  
e = File.foreach(“keywords”)  
loop {  
p e.next  
}  
’  
ruby 1.9.0 (2008-06-07 revision 16875) [i686-linux]  
“%{\n”  
“struct kwtable {const char \*name; int id[2]; enum lex\_state\_e  
state;};\n”  
-e:4: [BUG] Segmentation fault  
ruby 1.9.0 (2008-06-07 revision 16875) [i686-linux]

## – stack frame ------------ 0000 (0xb7ac2008): 00000004 0001 (0xb7ac200c): 00000001 0002 (0xb7ac2010): 00000004 0003 (0xb7ac2014): 00000001 0004 (0xb7ac2018): 0819c320 0005 (0xb7ac201c): 00000004 0006 (0xb7ac2020): 00000001 0007 (0xb7ac2024): 00000004 0008 (0xb7ac2028): 00000004 0009 (0xb7ac202c): b7b41f75 0010 (0xb7ac2030): 00000004 0011 (0xb7ac2034): b7ac2021 (= 6) 0012 (0xb7ac2038): 00000004 0013 (0xb7ac203c): 0819c320 0014 (0xb7ac2040): 00000004 0015 (0xb7ac2044): 00000001 \<- lfp \<- dfp – control frame ---------- c:0007 p:---- s:0016 b:0016 l:000015 d:000015 CFUNC :next c:0006 p:0010 s:0013 b:0012 l:000006 d:000011 BLOCK -e:4 c:0005 p:---- s:0012 b:0012 l:000011 d:000011 FINISH :class\_eval c:0004 p:---- s:0010 b:0010 l:000009 d:000009 CFUNC :loop c:0003 p:0024 s:0007 b:0007 l:000006 d:000006 TOP -e:3 c:0002 p:---- s:0004 b:0004 l:000003 d:000003 FINISH :private\_class\_method c:0001 p:0000 s:0002 b:0002 l:000001 d:000001 TOP :17

DBG\> : “-e:4:in `next'" DBG> : "-e:4:in`block in '”  
DBG\> : “-e:3:in `loop'" DBG> : "-e:3:in`'”  
– backtrace of native function call (Use addr2line) –  
0x810b7ba  
0x8132e9e  
0x8132efb  
0x80cb360  
0xb7f5d440  
0x80ff7d2  
0x81035eb  
0x810850e  
0x805aaf7  
0x80fa193  
0x8105fb3  
0x80ff7d2  
0x81035eb  
0x81037e3  
0x805a10c  
0x805a1af  
0x8058ba5  
0xb7dbeea8  
0x8058aa1

---

<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:** [June 9, 2008, 5:12am UTC](https://www.ruby-forum.com/t/bug-1-9-segv-by-file-foreach-keywords/139819/2 "2008-06-09T05:12:10Z")

</div>

e$B$J$+$@$G$9!#e(B

At Sun, 8 Jun 2008 00:27:53 +0900,  
Tanaka A. wrote in [ruby-dev:34988]:

> e$B0J2\<$N$h$&$K$9$k$He(B SEGV e$B$7$^$9!#e(B
> 
> % ./ruby -ve ’  
> e = File.foreach(“keywords”)  
> loop {  
> p e.next  
> }  
> ’

e$B\<j85$G:F8=$G$-$J$$$H;W$C$?$i!"=$@5$7$F$"$j$^$7$?!#$D$^$j!“e(BCe$B$G:ne(B  
e$B$i$l$?e(BEnumeratore$B$,e(Bsvare$B$r%”%/%;%9$9$k$H$$$&!“e(Btest\_knownbugs.rbe$B$Ke(B  
e$B$9$G$K$$$/$D$+$”$k%F%9%H$N%P%j%(!\<%7%g%s$G$9!#e(B

# Index: vm.c

— vm.c (revision 17037)  
+++ vm.c (working copy)  
@@ -99,11 +99,12 @@ rb\_control\_frame\_t \*  
vm\_get\_ruby\_level\_cfp(rb\_thread\_t \*th, rb\_control\_frame\_t \*cfp)  
{

- while (!RUBY\_VM\_CONTROL\_FRAME\_STACK\_OVERFLOW\_P(th, cfp)) {
- if (RUBY\_VM\_NORMAL\_ISEQ\_P(cfp-\>iseq)) {
- 

```
 return cfp;

```

- }

- if (RUBY\_VM\_CONTROL\_FRAME\_STACK\_OVERFLOW\_P(th, cfp)) return 0;
- while (!RUBY\_VM\_NORMAL\_ISEQ\_P(cfp-\>iseq)) {  
cfp = RUBY\_VM\_PREVIOUS\_CONTROL\_FRAME(cfp);
- if (RUBY\_VM\_CONTROL\_FRAME\_STACK\_OVERFLOW\_P(th, cfp)) {
- 

```
 return RUBY_VM_NEXT_CONTROL_FRAME(cfp);

```

- }  
}

- return 0;

- return cfp;  
}

@@ -527,4 +528,7 @@ vm\_cfp\_svar\_get(rb\_thread\_t \*th, rb\_cont  
while (cfp-\>pc == 0) {  
cfp++;

- if (RUBY\_VM\_CONTROL\_FRAME\_STACK\_OVERFLOW\_P(th, cfp)) {
- 

```
 return lfp_svar_get(th, 0, key);

```

- }  
}  
return lfp\_svar\_get(th, cfp-\>lfp, key);  
@@ -536,4 +540,8 @@ vm\_cfp\_svar\_set(rb\_thread\_t \*th, rb\_cont  
while (cfp-\>pc == 0) {  
cfp++;
- if (RUBY\_VM\_CONTROL\_FRAME\_STACK\_OVERFLOW\_P(th, cfp)) {
- 

```
 lfp_svar_set(th, 0, key, val);

```

- 

```
 return;

```

- }  
}  
lfp\_svar\_set(th, cfp-\>lfp, key, val);  
Index: vm\_insnhelper.c  
===================================================================  
— vm\_insnhelper.c (revision 17037)  
+++ vm\_insnhelper.c (working copy)  
@@ -843,21 +843,16 @@ static inline NODE \*  
lfp\_svar\_place(rb\_thread\_t \*th, VALUE \*lfp)  
{

- NODE \*svar;

- VALUE \*svar;

- if (th-\>local\_lfp != lfp) {
- svar = (NODE \*)lfp[-1];
- if ((VALUE)svar == Qnil) {
- 

```
 svar = NEW_IF(Qnil, Qnil, Qnil);

```

- 

```
 lfp[-1] = (VALUE)svar;

```

- }

- if (lfp && th-\>local\_lfp != lfp) {
- svar = &lfp[-1];  
}  
else {

- svar = (NODE \*)th-\>local\_svar;
- if ((VALUE)svar == Qnil) {
- 

```
 svar = NEW_IF(Qnil, Qnil, Qnil);

```

- 

```
 th->local_svar = (VALUE)svar;

```

- }

- svar = &th-\>local\_svar;
- }
- if (NIL\_P(\*svar)) {
- \*svar = (VALUE)NEW\_IF(Qnil, Qnil, Qnil);  
}

- return svar;

- return (NODE \*)\*svar;  
}