Thank you for your reply!
It would be great help if I could debug asanified executables. But I failed
to try it out.
I tried debugging with lldb, same codes as I pasted before.
Build:
/usr/local/Cellar/llvm34/3.4.1_1/bin/clang++-3.4 -O0 -g -fsanitize=address
longstack.cc -o ./longstack
Debug:
(lldb) target create ~/Test\ Projects/clang/longstack
Current executable set to '~/Test Projects/clang/longstack' (x86_64).
(lldb) run --stop-at-entry
Process 65604 launched: '/Users/tengxiang/Test Projects/clang/longstack'
(x86_64)
Process 65604 stopped
* thread #1: tid = 0xa5879, 0x00007fff5fc01028 dyld`_dyld_start, stop
reason = exec
frame #0: 0x00007fff5fc01028 dyld`_dyld_start
dyld`_dyld_start:
-> 0x7fff5fc01028: popq %rdi
0x7fff5fc01029: pushq $0
0x7fff5fc0102b: movq %rsp, %rbp
0x7fff5fc0102e: andq $-16, %rsp
(lldb) b foo
Breakpoint 1: where = longstack`foo(int) + 291 at longstack.cc:5, address =
0x0000000100000ab3
(lldb) c
Process 65604 resuming
Process 65604 stopped
* thread #1: tid = 0xa5879, 0x0000000100000ab3
longstack`foo(n=<unavailable>) + 291 at longstack.cc:5, queue =
'com.apple.main-thread, stop reason = breakpoint 1.1
frame #0: 0x0000000100000ab3 longstack`foo(n=<unavailable>) + 291 at
longstack.cc:5
2
3 void foo(int n)
4 {
-> 5 a[n]++;
6 foo(++n);
7 }
8
(lldb) p n
error: Couldn't materialize struct: size of variable n disagrees with the
ValueObject's size
Errored out in Execute, couldn't PrepareToExecuteJITExpression
See I can't print variable's value. And bt won't show parameters' value,
looks like
frame #0: 0x0000000100000ab3 longstack`foo(n=<unavailable>) + 291 at
longstack.cc:5
And then I tried remove -fsanitize=address, like
/usr/local/Cellar/llvm34/3.4.1_1/bin/clang++-3.4 -O0 -g longstack.cc -o
./longstack
It prints in lldb,
(lldb) p n
(int) $0 = 258504
Did I miss anything? Or is there a way to print variables in asan-ified
executables in debugging?
Regards,
-xiang
在 2014年7月14日星期一UTC+8下午5时02分05秒，kcc写道：
>
>
>
>
> On Mon, Jul 14, 2014 at 12:09 PM, Shiny Teng <[email protected]
> <javascript:>> wrote:
>
>> Hi experts,
>> I'm using llvm3.4.1 on OSX 10.9.3.
>> My codes,
>>
>> // longstack.cc
>> int* a;
>> void foo(int n)
>> {
>> a[n]++;
>> foo(++n);
>> }
>> int main(int argc, char** argv) {
>> a = new int[30];
>> foo(0);
>> }
>>
>> And it builds,
>> /usr/local/Cellar/llvm34/3.4.1_1/bin/clang-3.4 -O0 -g -fsanitize=address
>> longstack.cc -o ./longstack
>>
>> Only thing I set is,
>> export ASAN_SYMBOLIZER_PATH=/usr/local/Cellar/
>>
>> It reports,
>>
>> =================================================================
>> ==49571==ERROR: AddressSanitizer: heap-buffer-overflow on address
>> 0x60c00000bff8 at pc 0x10cffbb69 bp 0x7fff52c02a70 sp 0x7fff52c02a68
>> READ of size 4 at 0x60c00000bff8 thread T0
>> #0 0x10cffbb68 in foo(int) /Users/tengxiang/Test
>> Projects/clang/longstack.cc:5
>> #1 0x10cffbb8d in foo(int) /Users/tengxiang/Test
>> Projects/clang/longstack.cc:6
>> ...
>> #30 0x10cffbb8d in foo(int) /Users/tengxiang/Test
>> Projects/clang/longstack.cc:6
>> #31 0x10cffbdaa in main /Users/tengxiang/Test
>> Projects/clang/longstack.cc:11
>> #32 0x7fff8d8ef5fc in start (/usr/lib/system/libdyld.dylib+0x35fc)
>> #33 0x0
>>
>> ...
>> ==49571==ABORTING
>>
>> Please see the callstack foo(int) doesn't tell what's the inbound
>> parameter int's value.
>>
>> As comparison, I debugged it with lldb, it shows call stack with "bt".
>>
>>
>> ...
>> frame #258473: 0x0000000100000f33 longstacknormal`foo(n=32) + 51 at
>> longstack.cc:6
>> ...
>> frame #258504: 0x0000000100000f33 longstacknormal`foo(n=1) + 51 at
>> longstack.cc:6
>> frame #258505: 0x0000000100000f72 longstacknormal`main(argc=2,
>> argv=0x00007fff5fbffba0) + 50 at longstack.cc:11
>> frame #258506: 0x00007fff8d8ef5fd libdyld.dylib`start + 1
>>
>> Please see foo(n=32).
>>
>> My question is, did I miss anything or is it possible to get things like
>> that in ASAN report?
>>
>
> asan currently can not do this, sorry.
> Such functionality is far from trivial and we are not planing to implement
> it.
> However, you can attach gdb or lldb to asan-ified process when it has
> reported an error and get a more complete stack trace.
> https://code.google.com/p/address-sanitizer/wiki/AddressSanitizer#gdb
> If you think that such functionality in asan is worth the effort, feel
> free to file a bug report:
> https://code.google.com/p/address-sanitizer/issues/list
>
> Thanks!
>
> --kcc
>
>
>
>> Regards,
>> -xiang
>>
>> --
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