Re: __rw::__string_ref::size sigsegv

[Martin Sebor]

Mark Wright wrote:
Hello Martin and everyone,
Thanks.  I added -D_RWSTDDEBUG to the Makefile like:

I couldn't reproduce the SEGV with 4.2.0 but I did reproduce it on
the head of trunk (both with Sun C++/Solaris and gcc/Linux). I could
reproduce the RUI in set::insert(). It turns out the RUI is a known
issue (http://issues.apache.org/jira/browse/STDCXX-87) that hasn't
been analyzed yet. I'm not sure it's related to the SEGV. Let me
spend some time on it today and get back to you.

Just to confirm: you're still using 4.2.0, correct? And you used
the stock command line options to build the library without any
changes of your own (i.e., whatever our makefile uses)?

Martin

PS FWIW, here's my dbx output with check -all:

Read from uninitialized (rui) on thread 1:
Attempting to read 7 bytes at address 0xfffffd7fffdff3c9
    which is 201 bytes above the current stack pointer
[EMAIL PROTECTED] ([EMAIL PROTECTED]) stopped in std::pair<std::set<std::string>::iterator>, 
bool>::operator= at 0x000000000040c7da
0x000000000040c7da: operator=+0x002a:   hlt
(dbx) cont
Checking for memory leaks...

Actual leaks report    (actual leaks:            0  total size: 
 0 bytes
)



Possible leaks report  (possible leaks:          0  total size: 
 0 bytes
)


Checking for memory use...

Blocks in use report   (blocks in use:           0  total size: 
 0 bytes
)



execution completed, exit code is 0


setstr : setstr.o
        CC -D_RWSTDDEBUG -mt -g -xdebugformat=stabs -xs -m64 -library=%none 
-I/h/goanna/1/a_5.10_m64/c/include -o setstr setstr.o 
-L/h/goanna/1/a_5.10_m64/c/lib  -R/h/goanna/1/a_5.10_m64/c/lib -lstd15D

setstr.o : setstr.cpp
        CC -D_RWSTDDEBUG -mt -g -xdebugformat=stabs -xs -m64 -library=%none 
-I/h/goanna/1/a_5.10_m64/c/include -c setstr.cpp

clean:
        rm setstr setstr.o

compiled the following tiny program with Sun Studio 12 on Solaris 10u4 with 
stdcxx
compiled from subversion as 64 bit 15D:

#include <set>
#include <string>

std::set<std::string> setstr;

int main(int argc, char *argv[])
{
  std::copy(argv, argv + argc, std::inserter(setstr, setstr.end()));
  return 0;
}

and ran it, unfortunately though it still encounters a sigsegv.  So
I tried running it in dbx with Run Time Checking:

goanna% dbx setstr
Reading setstr
Reading ld.so.1
Reading libstd15D.so.4.2.0
Reading libCrun.so.1
Reading libm.so.2
Reading libthread.so.1
Reading libc.so.1
dbx: warning: undefined type number (0,72) at 
/h/goanna/2/eng/dev/stdcxx/setstr/setstr:setstr.cpp stab #64 
nJ_C_link_t(0,69):t(0,71)=*(0,72),
assuming type `(int {assumed})'
(dbx) check -all
access checking - ON
memuse checking - ON
(dbx) run
Running: setstr 
(process id 2876)
Reading rtcapihook.so
Reading libdl.so.1
Reading rtcaudit.so
Reading libmapmalloc.so.1
Reading libgen.so.1
Reading rtcboot.so
Reading librtc.so
RTC: Enabling Error Checking...
RTC: Running program...
Reading disasm.so
Read from uninitialized (rui) on thread 1:
Attempting to read 8 bytes at address 0x424818
    which is 32 bytes into a heap block of size 1280 bytes at 0x4247f8
This block was allocated from:
        [1] operator new() at 0xfffffd7fddb0a0e9 
        [2] __rw::__rw_allocate() at line 61 in "memory.cpp"
        [3] std::allocator<__rw::__rw_rb_tree_node<std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > 
>,std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::basic_string<char,std::char_traits<char>,std::allocator<char> 
>,__rw::__ident<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::basic_string<char,std::char_traits<char>,std::allocator<char> > > 
> >::allocate() at line 144 in "_allocator.h"
        [4] __rw::__rb_tree<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::basic_string<char,std::char_traits<char>,std::allocator<char> 
>,__rw::__ident<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::basic_string<char,std::char_traits<char>,std::allocator<char> > 
>,std::less<std::basic_string<char,std::char_traits<char>,std::allocator<char> > >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > 
>::_C_add_new_buffer() at line 143 in "_tree.cc"
        [5] __rw::__rb_tree<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::basic_string<char,std::char_traits<char>,std::allocator<char> 
>,__rw::__ident<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::basic_string<char,std::char_traits<char>,std::allocator<char> > 
>,std::less<std::basic_string<char,std::char_traits<char>,std::allocator<char> > >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > 
>::_C_get_link() at line 360 in "_tree.h"
        [6] __rw::__rb_tree<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::basic_string<char,std::char_traits<char>,std::allocator<char> 
>,__rw::__ident<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::basic_string<char,std::char_traits<char>,std::allocator<char> > 
>,std::less<std::basic_string<char,std::char_traits<char>,std::allocator<char> > >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > 
>::_C_get_node() at line 393 in "_tree.h"
        [7] __rw::__rb_tree<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::basic_string<char,std::char_traits<char>,std::allocator<char> 
>,__rw::__ident<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::basic_string<char,std::char_traits<char>,std::allocator<char> > 
>,std::less<std::basic_string<char,std::char_traits<char>,std::allocator<char> > >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > 
>::_C_init() at line 460 in "_tree.h"
        [8] __rw::__rb_tree<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::basic_string<char,std::char_traits<char>,std::allocator<char> 
>,__rw::__ident<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::basic_string<char,std::char_traits<char>,std::allocator<char> > 
>,std::less<std::basic_string<char,std::char_traits<char>,std::allocator<char> > >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > 
>::__rb_tree() at line 56 in "_tree.cc"

Variable is 'this'
[EMAIL PROTECTED] ([EMAIL PROTECTED]) stopped in 
std::basic_string<char,std::char_traits<char>,std::allocator<char> >::_C_pref at line 842 
in file "string"
  842           return _RWSTD_REINTERPRET_CAST (_C_string_ref_type*, _C_data) - 1; 
(dbx) where
current thread: [EMAIL PROTECTED]
=>[1] std::basic_string<char,std::char_traits<char>,std::allocator<char> >::_C_pref(this 
= 0x424818), line 842 in "string"
  [2] std::basic_string<char,std::char_traits<char>,std::allocator<char> >::size(this = 
0x424818), line 247 in "string"
  [3] std::basic_string<char,std::char_traits<char>,std::allocator<char> >::size(this = 
0x424818), line 247 in "string"
  [4] std::basic_string<char,std::char_traits<char>,std::allocator<char> >::compare(this 
= 0x424818, __str = CLASS), line 1186 in "string"
  [5] std::operator< <char,std::char_traits<char>,std::allocator<char> >(__lhs = CLASS, 
__rhs = CLASS), line 1356 in "string"
  [6] std::less<std::basic_string<char,std::char_traits<char>,std::allocator<char> > 
>::operator()(this = 0x422778, __x = CLASS, __y = CLASS), line 94 in "_funcbase.h"
  [7] __rw::__rb_tree<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::basic_string<char,std::char_traits<char>,std::allocator<char> 
>,__rw::__ident<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::basic_string<char,std::char_traits<char>,std::allocator<char> > 
>,std::less<std::basic_string<char,std::char_traits<char>,std::allocator<char> > >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > 
>::insert(this = 0x422748, __it = CLASS, __v = CLASS, __dup = false), line 356 in "_tree.cc"
  [8] __rw::__rb_tree<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::basic_string<char,std::char_traits<char>,std::allocator<char> 
>,__rw::__ident<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::basic_string<char,std::char_traits<char>,std::allocator<char> > 
>,std::less<std::basic_string<char,std::char_traits<char>,std::allocator<char> > >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > 
>::insert(this = 0x422748, __it = CLASS, __x = CLASS, __dup = false), line 592 in "_tree.h"
  [9] std::set<std::basic_string<char,std::char_traits<char>,std::allocator<char> 
>,std::less<std::basic_string<char,std::char_traits<char>,std::allocator<char> > 
>,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > >::insert(this = 0x422748, __it = CLASS, 
__x = CLASS), line 172 in "set"
  [10] std::insert_iterator<std::set<std::basic_string<char,std::char_traits<char>,std::allocator<char> 
>,std::less<std::basic_string<char,std::char_traits<char>,std::allocator<char> > 
>,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > > >::operator=(this = 0xfffffd7fffdfd530, __x 
= CLASS), line 501 in "_iterator.h"
  [11] std::copy<char**,std::insert_iterator<std::set<std::basic_string<char,std::char_traits<char>,std::allocator<char> 
>,std::less<std::basic_string<char,std::char_traits<char>,std::allocator<char> > 
>,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > > > >(__first = 0xfffffd7fffdfd618, __last = 
0xfffffd7fffdfd620, __res = CLASS), line 95 in "_algobase.h"
  [12] main(argc = 1, argv = 0xfffffd7fffdfd618), line 8 in "setstr.cpp"
(dbx) print -r *this
*this = {
    basic_string<char,std::char_traits<char>,std::allocator<char> >::_C_data    
 = (nil)
    basic_string<char,std::char_traits<char>,std::allocator<char> >::npos       
 = -1
    _C_null_ref                                                                  = struct 
__rw::__null_ref<char,std::char_traits<char>,std::allocator<char> > /* STATIC 
CLASS */
}
(dbx) cont
Read from unallocated (rua) on thread 1:
Attempting to read 8 bytes at address 0xfffffffffffffff8
[EMAIL PROTECTED] ([EMAIL PROTECTED]) stopped in 
__rw::__string_ref<char,std::char_traits<char>,std::allocator<char> >::size at line 211 
in file "_strref.h"
  211           return _C_size._C_size;
(dbx) where
current thread: [EMAIL PROTECTED]
=>[1] __rw::__string_ref<char,std::char_traits<char>,std::allocator<char> >::size(this = 
0xffffffffffffffe8), line 211 in "_strref.h"
  [2] std::basic_string<char,std::char_traits<char>,std::allocator<char> >::size(this = 
0xffffffffffffffe8), line 247 in "string"
  [3] std::basic_string<char,std::char_traits<char>,std::allocator<char> >::size(this = 
0x424818), line 247 in "string"
  [4] std::basic_string<char,std::char_traits<char>,std::allocator<char> >::compare(this 
= 0x424818, __str = CLASS), line 1186 in "string"
  [5] std::operator< <char,std::char_traits<char>,std::allocator<char> >(__lhs = CLASS, 
__rhs = CLASS), line 1356 in "string"
  [6] std::less<std::basic_string<char,std::char_traits<char>,std::allocator<char> > 
>::operator()(this = 0x422778, __x = CLASS, __y = CLASS), line 94 in "_funcbase.h"
  [7] __rw::__rb_tree<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::basic_string<char,std::char_traits<char>,std::allocator<char> 
>,__rw::__ident<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::basic_string<char,std::char_traits<char>,std::allocator<char> > 
>,std::less<std::basic_string<char,std::char_traits<char>,std::allocator<char> > >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > 
>::insert(this = 0x422748, __it = CLASS, __v = CLASS, __dup = false), line 356 in "_tree.cc"
  [8] __rw::__rb_tree<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::basic_string<char,std::char_traits<char>,std::allocator<char> 
>,__rw::__ident<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::basic_string<char,std::char_traits<char>,std::allocator<char> > 
>,std::less<std::basic_string<char,std::char_traits<char>,std::allocator<char> > >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > 
>::insert(this = 0x422748, __it = CLASS, __x = CLASS, __dup = false), line 592 in "_tree.h"
  [9] std::set<std::basic_string<char,std::char_traits<char>,std::allocator<char> 
>,std::less<std::basic_string<char,std::char_traits<char>,std::allocator<char> > 
>,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > >::insert(this = 0x422748, __it = CLASS, 
__x = CLASS), line 172 in "set"
  [10] std::insert_iterator<std::set<std::basic_string<char,std::char_traits<char>,std::allocator<char> 
>,std::less<std::basic_string<char,std::char_traits<char>,std::allocator<char> > 
>,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > > >::operator=(this = 0xfffffd7fffdfd530, __x 
= CLASS), line 501 in "_iterator.h"
  [11] std::copy<char**,std::insert_iterator<std::set<std::basic_string<char,std::char_traits<char>,std::allocator<char> 
>,std::less<std::basic_string<char,std::char_traits<char>,std::allocator<char> > 
>,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > > > >(__first = 0xfffffd7fffdfd618, __last = 
0xfffffd7fffdfd620, __res = CLASS), line 95 in "_algobase.h"
  [12] main(argc = 1, argv = 0xfffffd7fffdfd618), line 8 in "setstr.cpp"
(dbx) print -r *this
dbx: cannot access address 0xffffffffffffffe8
(dbx) frame 2
Current function is 
std::basic_string<char,std::char_traits<char>,std::allocator<char> >::size
  247           return _C_pref ()->size ();
(dbx) print -r *this
dbx: cannot access address 0xffffffffffffffe8
(dbx) frame 4
Current function is 
std::basic_string<char,std::char_traits<char>,std::allocator<char> >::compare
 1186       const size_type __n1    = size ();
(dbx) 
(dbx) print -r *this
*this = {
    basic_string<char,std::char_traits<char>,std::allocator<char> >::_C_data    
 = (nil)
    basic_string<char,std::char_traits<char>,std::allocator<char> >::npos       
 = -1
    _C_null_ref                                                                  = struct 
__rw::__null_ref<char,std::char_traits<char>,std::allocator<char> > /* STATIC 
CLASS */
}
(dbx) cont
signal SEGV (no mapping at the fault address) at 0xfffffd7fe3f3cd00
0xfffffd7fe3f3cd00: __rtc_catch_segv       :    pushq    %rbp
Current function is 
std::basic_string<char,std::char_traits<char>,std::allocator<char> >::size
  247           return _C_pref ()->size ();
(dbx) where
current thread: [EMAIL PROTECTED]
  [1] 0xfffffd7fd7405fcf(0xffffffffffffffe8, 0xfffffd7fffdfd4d8, 0xfffffd7fffdfd4d8, 0x0, 0xffffffffffffffe8, 0x4247f8), at 0xfffffd7fd7405fcf 
  [2] __sighndlr(0x0, 0x0, 0x0, 0x0, 0x0, 0x0), at 0xfffffd7fd9fd1216 
=>[3] std::basic_string<char,std::char_traits<char>,std::allocator<char> >::size(this = 0x424818), line 247 in "string"
  [4] std::basic_string<char,std::char_traits<char>,std::allocator<char> >::compare(this 
= 0x424818, __str = CLASS), line 1186 in "string"
  [5] std::operator< <char,std::char_traits<char>,std::allocator<char> >(__lhs = CLASS, 
__rhs = CLASS), line 1356 in "string"
  [6] std::less<std::basic_string<char,std::char_traits<char>,std::allocator<char> > 
>::operator()(this = 0x422778, __x = CLASS, __y = CLASS), line 94 in "_funcbase.h"
  [7] __rw::__rb_tree<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::basic_string<char,std::char_traits<char>,std::allocator<char> 
>,__rw::__ident<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::basic_string<char,std::char_traits<char>,std::allocator<char> > 
>,std::less<std::basic_string<char,std::char_traits<char>,std::allocator<char> > >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > 
>::insert(this = 0x422748, __it = CLASS, __v = CLASS, __dup = false), line 356 in "_tree.cc"
  [8] __rw::__rb_tree<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::basic_string<char,std::char_traits<char>,std::allocator<char> 
>,__rw::__ident<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::basic_string<char,std::char_traits<char>,std::allocator<char> > 
>,std::less<std::basic_string<char,std::char_traits<char>,std::allocator<char> > >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > 
>::insert(this = 0x422748, __it = CLASS, __x = CLASS, __dup = false), line 592 in "_tree.h"
  [9] std::set<std::basic_string<char,std::char_traits<char>,std::allocator<char> 
>,std::less<std::basic_string<char,std::char_traits<char>,std::allocator<char> > 
>,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > >::insert(this = 0x422748, __it = CLASS, 
__x = CLASS), line 172 in "set"
  [10] std::insert_iterator<std::set<std::basic_string<char,std::char_traits<char>,std::allocator<char> 
>,std::less<std::basic_string<char,std::char_traits<char>,std::allocator<char> > 
>,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > > >::operator=(this = 0xfffffd7fffdfd530, __x 
= CLASS), line 501 in "_iterator.h"
  [11] std::copy<char**,std::insert_iterator<std::set<std::basic_string<char,std::char_traits<char>,std::allocator<char> 
>,std::less<std::basic_string<char,std::char_traits<char>,std::allocator<char> > 
>,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > > > >(__first = 0xfffffd7fffdfd618, __last = 
0xfffffd7fffdfd620, __res = CLASS), line 95 in "_algobase.h"
  [12] main(argc = 1, argv = 0xfffffd7fffdfd618), line 8 in "setstr.cpp"
(dbx) print -r *this
*this = {
    basic_string<char,std::char_traits<char>,std::allocator<char> >::_C_data    
 = (nil)
    basic_string<char,std::char_traits<char>,std::allocator<char> >::npos       
 = -1
    _C_null_ref                                                                  = struct 
__rw::__null_ref<char,std::char_traits<char>,std::allocator<char> > /* STATIC 
CLASS */
}
(dbx) 

Thanks, Mark