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Bug #13596
closedSegfault when catching SystemStackError in eval
Status:
Closed
Assignee:
-
Target version:
-
ruby -v:
ruby 2.4.1p111 (2017-03-22 revision 58053) [x86_64-linux]
Description
This minimal testcase will crash most ruby versions with a SIGSEGV (though it's likely that other constructions could trigger the same behavior). Effectively, after the first SystemStackError that is caught from eval, a subsequent stack overflow will crash ruby rather than triggering another SystemStackError.
Failing testcase:
ruby -e "code = '+1' * 100000; 2.times {begin; eval code; rescue SystemStackError => e; p e; end}"
#<SystemStackError: stack level too deep>
[1] 23587 segmentation fault (core dumped) ruby -e
Succeeding testcase:
ruby -e "def x; x; end; 2.times {begin; x; rescue SystemStackError => e; p e; end}"
#<SystemStackError: stack level too deep>
#<SystemStackError: stack level too deep>
Updated by mjones (Morgan Jones) over 7 years ago
Here's a GDB trace with VMDEBUG=1 for a Ruby 2.4.1 checkout. It appears that the crash occurs when setting up the frame in iseq_compile_each, when the application tries to access rsp+8 (0x7fffff7fed50+8). This lands in the redzone page, and a segfault occurs.
$ gdb --args ./miniruby -e "code = '+1' * 100000; 2.times {begin; eval(code); rescue SystemStackError; end}"
GNU gdb (GDB) 7.12.1
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Reading symbols from ./miniruby...done.
warning: File "/home/numinit/ruby/.gdbinit" auto-loading has been declined by your `auto-load safe-path' set to "$debugdir:$datadir/auto-load".
To enable execution of this file add
add-auto-load-safe-path /home/numinit/ruby/.gdbinit
line to your configuration file "/home/numinit/.gdbinit".
To completely disable this security protection add
set auto-load safe-path /
line to your configuration file "/home/numinit/.gdbinit".
For more information about this security protection see the
"Auto-loading safe path" section in the GDB manual. E.g., run from the shell:
info "(gdb)Auto-loading safe path"
(gdb) run
Starting program: /home/numinit/ruby/miniruby -e code\ =\ \'+1\'\ \*\ 100000\;\ 2.times\ \{begin\;\ eval\(code\)\;\ rescue\ SystemStackError\;\ end\}
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/usr/lib/libthread_db.so.1".
[New Thread 0x7ffff7e59700 (LWP 16284)]
| 0000 trace 1 ( 1)
| 0002 putstring "+1"
| 0004 putobject 100000
| 0006 opt_mult <callinfo!mid:*, argc:1, ARGS_SIMPLE>, <callcache>
| 0009 setlocal_OP__WC__0 3
| 0011 putobject 2
| 0013 send <callinfo!mid:times, argc:0>, <callcache>, block in <main>
| 0000 trace 256 ( 1)
| 0002 trace 1
| 0004 putself
| 0005 getlocal_OP__WC__1 3
| 0007 opt_send_without_block <callinfo!mid:eval, argc:1, FCALL|ARGS_SIMPLE>, <callcache>
Thread 1 "miniruby" received signal SIGSEGV, Segmentation fault.
iseq_compile_each (iseq=iseq@entry=0x555556709bc0, ret=ret@entry=0x7fffff7ff0d0, node=0x5555565c45f8,
popped=popped@entry=0) at compile.c:3961
3961 {
=> 0x00005555555afeea <iseq_compile_each+26>: 89 4c 24 08 mov DWORD PTR [rsp+0x8],ecx
(gdb) list
3956 node: Ruby compiled node
3957 popped: This node will be popped
3958 */
3959 static int
3960 iseq_compile_each(rb_iseq_t *iseq, LINK_ANCHOR *const ret, NODE *node, int popped)
3961 {
3962 enum node_type type;
3963 LINK_ELEMENT *saved_last_element = 0;
3964 int line;
3965
(gdb) info reg
rax 0x7fffff7ff130 140737479962928
rbx 0x555556709bc0 93825010801600
rcx 0x0 0
rdx 0x5555565c45f8 93825009468920
rsi 0x7fffff7ff0d0 140737479962832
rdi 0x555556709bc0 93825010801600
rbp 0x1 0x1
rsp 0x7fffff7fed50 0x7fffff7fed50
r8 0x3 3
r9 0x23 35
r10 0x0 0
r11 0x7ffff6fa64c0 140737336992960
r12 0x1 1
r13 0x5555565c4580 93825009468800
r14 0x7fffff7ff0d0 140737479962832
r15 0xa31b 41755
rip 0x5555555afeea 0x5555555afeea <iseq_compile_each+26>
eflags 0x10202 [ IF RF ]
cs 0x33 51
ss 0x2b 43
ds 0x0 0
es 0x0 0
fs 0x0 0
gs 0x0 0
(gdb) info proc map
process 16280
Mapped address spaces:
Start Addr End Addr Size Offset objfile
0x555555554000 0x555555853000 0x2ff000 0x0 /home/numinit/ruby/miniruby
0x555555a53000 0x555555a58000 0x5000 0x2ff000 /home/numinit/ruby/miniruby
0x555555a58000 0x555555a59000 0x1000 0x304000 /home/numinit/ruby/miniruby
0x555555a59000 0x555556720000 0xcc7000 0x0 [heap]
0x7ffff6d35000 0x7ffff6e36000 0x101000 0x0
0x7ffff6e36000 0x7ffff6fd1000 0x19b000 0x0 /usr/lib/libc-2.25.so
0x7ffff6fd1000 0x7ffff71d0000 0x1ff000 0x19b000 /usr/lib/libc-2.25.so
0x7ffff71d0000 0x7ffff71d4000 0x4000 0x19a000 /usr/lib/libc-2.25.so
0x7ffff71d4000 0x7ffff71d6000 0x2000 0x19e000 /usr/lib/libc-2.25.so
0x7ffff71d6000 0x7ffff71da000 0x4000 0x0
0x7ffff71da000 0x7ffff72ec000 0x112000 0x0 /usr/lib/libm-2.25.so
0x7ffff72ec000 0x7ffff74eb000 0x1ff000 0x112000 /usr/lib/libm-2.25.so
0x7ffff74eb000 0x7ffff74ec000 0x1000 0x111000 /usr/lib/libm-2.25.so
0x7ffff74ec000 0x7ffff74ed000 0x1000 0x112000 /usr/lib/libm-2.25.so
0x7ffff74ed000 0x7ffff74f5000 0x8000 0x0 /usr/lib/libcrypt-2.25.so
0x7ffff74f5000 0x7ffff76f5000 0x200000 0x8000 /usr/lib/libcrypt-2.25.so
0x7ffff76f5000 0x7ffff76f6000 0x1000 0x8000 /usr/lib/libcrypt-2.25.so
0x7ffff76f6000 0x7ffff76f7000 0x1000 0x9000 /usr/lib/libcrypt-2.25.so
0x7ffff76f7000 0x7ffff7725000 0x2e000 0x0
0x7ffff7725000 0x7ffff7728000 0x3000 0x0 /usr/lib/libdl-2.25.so
0x7ffff7728000 0x7ffff7927000 0x1ff000 0x3000 /usr/lib/libdl-2.25.so
0x7ffff7927000 0x7ffff7928000 0x1000 0x2000 /usr/lib/libdl-2.25.so
0x7ffff7928000 0x7ffff7929000 0x1000 0x3000 /usr/lib/libdl-2.25.so
0x7ffff7929000 0x7ffff79bb000 0x92000 0x0 /usr/lib/libgmp.so.10.3.2
0x7ffff79bb000 0x7ffff7bba000 0x1ff000 0x92000 /usr/lib/libgmp.so.10.3.2
0x7ffff7bba000 0x7ffff7bbb000 0x1000 0x91000 /usr/lib/libgmp.so.10.3.2
0x7ffff7bbb000 0x7ffff7bbc000 0x1000 0x92000 /usr/lib/libgmp.so.10.3.2
0x7ffff7bbc000 0x7ffff7bd5000 0x19000 0x0 /usr/lib/libpthread-2.25.so
0x7ffff7bd5000 0x7ffff7dd4000 0x1ff000 0x19000 /usr/lib/libpthread-2.25.so
0x7ffff7dd4000 0x7ffff7dd5000 0x1000 0x18000 /usr/lib/libpthread-2.25.so
0x7ffff7dd5000 0x7ffff7dd6000 0x1000 0x19000 /usr/lib/libpthread-2.25.so
0x7ffff7dd6000 0x7ffff7dda000 0x4000 0x0
0x7ffff7dda000 0x7ffff7dfd000 0x23000 0x0 /usr/lib/ld-2.25.so
0x7ffff7e25000 0x7ffff7e56000 0x31000 0x0
0x7ffff7e56000 0x7ffff7e57000 0x1000 0x0
0x7ffff7e57000 0x7ffff7e5a000 0x3000 0x0
0x7ffff7e5a000 0x7ffff7ff2000 0x198000 0x0 /usr/lib/locale/locale-archive
0x7ffff7ff2000 0x7ffff7ff8000 0x6000 0x0
0x7ffff7ff8000 0x7ffff7ffa000 0x2000 0x0 [vvar]
0x7ffff7ffa000 0x7ffff7ffc000 0x2000 0x0 [vdso]
0x7ffff7ffc000 0x7ffff7ffd000 0x1000 0x22000 /usr/lib/ld-2.25.so
0x7ffff7ffd000 0x7ffff7ffe000 0x1000 0x23000 /usr/lib/ld-2.25.so
0x7ffff7ffe000 0x7ffff7fff000 0x1000 0x0
0x7fffff7ff000 0x7ffffffff000 0x800000 0x0 [stack]
0xffffffffff600000 0xffffffffff601000 0x1000 0x0 [vsyscall]
(gdb) bt
#0 iseq_compile_each (iseq=iseq@entry=0x555556709bc0, ret=ret@entry=0x7fffff7ff0d0, node=0x5555565c45f8,
popped=popped@entry=0) at compile.c:3961
#1 0x00005555555b08cf in iseq_compile_each (iseq=iseq@entry=0x555556709bc0, ret=ret@entry=0x7fffff7ff3e0,
node=0x5555565c4580, popped=popped@entry=0) at compile.c:5265
#2 0x00005555555b08cf in iseq_compile_each (iseq=iseq@entry=0x555556709bc0, ret=ret@entry=0x7fffff7ff6f0,
node=0x5555565c4508, popped=popped@entry=0) at compile.c:5265
#3 0x00005555555b08cf in iseq_compile_each (iseq=iseq@entry=0x555556709bc0, ret=ret@entry=0x7fffff7ffa00,
node=0x5555565c4490, popped=popped@entry=0) at compile.c:5265
#4 0x00005555555b08cf in iseq_compile_each (iseq=iseq@entry=0x555556709bc0, ret=ret@entry=0x7fffff7ffd10,
node=0x5555565c4418, popped=popped@entry=0) at compile.c:5265
#5 0x00005555555b08cf in iseq_compile_each (iseq=iseq@entry=0x555556709bc0, ret=ret@entry=0x7fffff800020,
node=0x5555565c43a0, popped=popped@entry=0) at compile.c:5265
#6 0x00005555555b08cf in iseq_compile_each (iseq=iseq@entry=0x555556709bc0, ret=ret@entry=0x7fffff800330,
node=0x5555565c4328, popped=popped@entry=0) at compile.c:5265
#7 0x00005555555b08cf in iseq_compile_each (iseq=iseq@entry=0x555556709bc0, ret=ret@entry=0x7fffff800640,
node=0x5555565c42b0, popped=popped@entry=0) at compile.c:5265
#8 0x00005555555b08cf in iseq_compile_each (iseq=iseq@entry=0x555556709bc0, ret=ret@entry=0x7fffff800950,
node=0x5555565c4238, popped=popped@entry=0) at compile.c:5265
#9 0x00005555555b08cf in iseq_compile_each (iseq=iseq@entry=0x555556709bc0, ret=ret@entry=0x7fffff800c60,
node=0x5555565c41c0, popped=popped@entry=0) at compile.c:5265
#10 0x00005555555b08cf in iseq_compile_each (iseq=iseq@entry=0x555556709bc0, ret=ret@entry=0x7fffff800f70,
node=0x5555565c4148, popped=popped@entry=0) at compile.c:5265
#11 0x00005555555b08cf in iseq_compile_each (iseq=iseq@entry=0x555556709bc0, ret=ret@entry=0x7fffff801280,
node=0x5555565c40d0, popped=popped@entry=0) at compile.c:5265
#12 0x00005555555b08cf in iseq_compile_each (iseq=iseq@entry=0x555556709bc0, ret=ret@entry=0x7fffff801590,
node=0x5555565c4058, popped=popped@entry=0) at compile.c:5265
#13 0x00005555555b08cf in iseq_compile_each (iseq=iseq@entry=0x555556709bc0, ret=ret@entry=0x7fffff8018a0,
node=0x5555565cbfb0, popped=popped@entry=0) at compile.c:5265
*snip*
#10682 0x00005555555b08cf in iseq_compile_each (iseq=iseq@entry=0x555556709bc0, ret=ret@entry=0x7fffffffba70, node=0x555556709e40, popped=popped@entry=0) at compile.c:5265
#10683 0x00005555555b08cf in iseq_compile_each (iseq=iseq@entry=0x555556709bc0, ret=ret@entry=0x7fffffffbd80, node=0x555556709dc8, popped=popped@entry=0) at compile.c:5265
#10684 0x00005555555b08cf in iseq_compile_each (iseq=iseq@entry=0x555556709bc0, ret=ret@entry=0x7fffffffc090, node=0x555556709d50, popped=popped@entry=0) at compile.c:5265
#10685 0x00005555555b08cf in iseq_compile_each (iseq=iseq@entry=0x555556709bc0, ret=ret@entry=0x7fffffffc3a0, node=0x555556709cd8, popped=popped@entry=0) at compile.c:5265
#10686 0x00005555555b08cf in iseq_compile_each (iseq=iseq@entry=0x555556709bc0, ret=ret@entry=0x7fffffffc9a0, node=0x555556709c60, popped=popped@entry=0) at compile.c:5265
#10687 0x00005555555b301f in iseq_compile_each (iseq=iseq@entry=0x555556709bc0, ret=ret@entry=0x7fffffffc9a0, node=0x555556709be8, popped=0) at compile.c:6280
#10688 0x00005555555bc791 in rb_iseq_compile_node (iseq=iseq@entry=0x555556709bc0, node=node@entry=0x555556709c38) at compile.c:651
#10689 0x000055555563cb94 in rb_iseq_new_with_opt (node=node@entry=0x555556709c38, name=93824997742080, path=93824997738840, absolute_path=absolute_path@entry=8, first_lineno=first_lineno@entry=3, parent=parent@entry=0x555555a955d8, type=ISEQ_TYPE_EVAL, option=0x7fffffffcae0) at iseq.c:483
#10690 0x000055555563dc04 in rb_iseq_compile_with_option (src=<optimized out>, src@entry=93824997740280, file=<optimized out>, file@entry=93824997738840, absolute_path=absolute_path@entry=8, line=3, base_block=base_block@entry=0x7fffffffcba0, opt=opt@entry=8) at iseq.c:650
#10691 0x000055555576a149 in eval_string_with_cref (self=self@entry=93824997975240, src=93824997740280, scope=8, cref_arg=cref_arg@entry=0x0, filename=<optimized out>, lineno=<optimized out>) at vm_eval.c:1345
#10692 0x000055555576a67e in eval_string (line=<optimized out>, file=<optimized out>, scope=<optimized out>, src=<optimized out>, self=93824997975240) at vm_eval.c:1397
#10693 rb_f_eval (argc=1, argv=<optimized out>, self=93824997975240) at vm_eval.c:1436
#10694 0x000055555575b7e7 in vm_call_cfunc_with_frame (ci=0x555555b846d0, cc=<optimized out>, calling=<optimized out>, reg_cfp=0x7ffff6e34f50, th=0x555555a6d5d0) at vm_insnhelper.c:1752
#10695 vm_call_cfunc (th=0x555555a6d5d0, reg_cfp=0x7ffff6e34f50, calling=<optimized out>, ci=0x555555b846d0, cc=<optimized out>) at vm_insnhelper.c:1847
#10696 0x00005555557697e3 in vm_call_method (th=0x555555a6d5d0, cfp=0x7ffff6e34f50, calling=<optimized out>, ci=<optimized out>, cc=<optimized out>) at vm_insnhelper.c:2292
#10697 0x000055555576286e in vm_exec_core (th=th@entry=0x555555a6d5d0, initial=initial@entry=0) at insns.def:1066
#10698 0x0000555555767dea in vm_exec (th=th@entry=0x555555a6d5d0) at vm.c:1727
#10699 0x0000555555768b34 in invoke_block (captured=<optimized out>, opt_pc=<optimized out>, type=<optimized out>, cref=0x0, self=93824997975240, iseq=<optimized out>, th=0x555555a6d5d0) at vm.c:969
#10700 invoke_iseq_block_from_c (th=0x555555a6d5d0, captured=<optimized out>, self=93824997975240, argc=<optimized out>, argv=<optimized out>, passed_block_handler=<optimized out>, cref=0x0, splattable=0, is_lambda=0) at vm.c:1014
#10701 0x0000555555770048 in invoke_block_from_c_splattable (argc=<optimized out>, passed_block_handler=<optimized out>, cref=<optimized out>, is_lambda=<optimized out>, splattable=<optimized out>, argv=<optimized out>, block_handler=<optimized out>, th=<optimized out>) at vm.c:1032
#10702 vm_yield (argc=1, argv=0x7fffffffd4f8, th=0x555555a6d5d0) at vm.c:1074
#10703 rb_yield_0 (argv=0x7fffffffd4f8, argc=1) at vm_eval.c:1010
#10704 rb_yield_1 (val=<optimized out>, val@entry=1) at vm_eval.c:1016
#10705 0x00005555556574a0 in int_dotimes (num=5) at numeric.c:4977
#10706 0x000055555575b7e7 in vm_call_cfunc_with_frame (ci=0x555555b842e0, cc=<optimized out>, calling=<optimized out>, reg_cfp=0x7ffff6e34fb0, th=0x555555a6d5d0) at vm_insnhelper.c:1752
#10707 vm_call_cfunc (th=0x555555a6d5d0, reg_cfp=0x7ffff6e34fb0, calling=<optimized out>, ci=0x555555b842e0, cc=<optimized out>) at vm_insnhelper.c:1847
#10708 0x00005555557697e3 in vm_call_method (th=0x555555a6d5d0, cfp=0x7ffff6e34fb0, calling=<optimized out>, ci=<optimized out>, cc=<optimized out>) at vm_insnhelper.c:2292
#10709 0x000055555576246a in vm_exec_core (th=th@entry=0x555555a6d5d0, initial=initial@entry=0) at insns.def:967
#10710 0x0000555555767dea in vm_exec (th=0x555555a6d5d0) at vm.c:1727
#10711 0x00005555557718ae in rb_iseq_eval_main (iseq=iseq@entry=0x555555a95a88) at vm.c:1973
#10712 0x00005555555f8a5d in ruby_exec_internal (n=0x555555a95a88) at eval.c:244
#10713 0x00005555555fc2bf in ruby_exec_node (n=<optimized out>) at eval.c:308
#10714 ruby_run_node (n=<optimized out>) at eval.c:300
#10715 0x0000555555578dcb in main (argc=<optimized out>, argv=<optimized out>) at main.c:36
Updated by mjones (Morgan Jones) over 7 years ago
Updated description to add a successful testcase.
Updated by nobu (Nobuyoshi Nakada) over 7 years ago
- Is duplicate of Bug #13164: A second `SystemStackError` exception results in `Segmentation fault (core dumped)` added
Updated by nobu (Nobuyoshi Nakada) over 7 years ago
- Status changed from Open to Closed
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