Hello!

Have you enabled multi-thread support for libevent?

evthread_use_pthreads()

Or

evthread_use_windows_threads()

If yes, can you please try one of the following to get more details?

• compile libevent and your program with clang -fsanitize=address,undefined
• compile libevent and your program with clang -fsanitize=thread,undefined

And something less preferable but easier:

• run under valgrind --tool=memcheck
• run under valgrind --tool=drd or valgrind --tool=helgrind

Hello!

Have you enabled multi-thread support for libevent?

evthread_use_pthreads()

Or

evthread_use_windows_threads()

If yes, can you please try one of the following to get more details?

• compile libevent and your program with clang -fsanitize=address,undefined
• compile libevent and your program with clang -fsanitize=thread,undefined

And something less preferable but easier:

• run under valgrind --tool=memcheck
• run under valgrind --tool=drd or valgrind --tool=helgrind

Not about multi-thread. It seems arc4_getbyte always returns 6c

In another case, arc4_getbyte always returns 2c

0x55b4e26eef20 : 0x2c2ceb3a 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c
0x55b4e26eef30 <rs+16>: 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c
0x55b4e26eef40 <rs+32>: 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c
0x55b4e26eef50 <rs+48>: 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c
0x55b4e26eef60 <rs+64>: 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c
0x55b4e26eef70 <rs+80>: 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c
0x55b4e26eef80 <rs+96>: 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c
0x55b4e26eef90 <rs+112>: 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c
0x55b4e26eefa0 <rs+128>: 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c
0x55b4e26eefb0 <rs+144>: 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c
0x55b4e26eefc0 <rs+160>: 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c
0x55b4e26eefd0 <rs+176>: 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c
0x55b4e26eefe0 <rs+192>: 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c
0x55b4e26eeff0 <rs+208>: 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c
0x55b4e26ef000 <rs+224>: 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c
0x55b4e26ef010 <rs+240>: 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c 0x2c2c2c2c
0x55b4e26ef020 <rs+256>: 0x00002c2c 0x00005f45 0x0009eadf 0x00000000

0x55a725955f20 : 0x6c6cd8a2 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c
0x55a725955f30 <rs+16>: 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c
0x55a725955f40 <rs+32>: 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c
0x55a725955f50 <rs+48>: 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c
0x55a725955f60 <rs+64>: 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c
0x55a725955f70 <rs+80>: 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c
0x55a725955f80 <rs+96>: 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c
0x55a725955f90 <rs+112>: 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c
0x55a725955fa0 <rs+128>: 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c
0x55a725955fb0 <rs+144>: 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c
0x55a725955fc0 <rs+160>: 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c
0x55a725955fd0 <rs+176>: 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c
0x55a725955fe0 <rs+192>: 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c
0x55a725955ff0 <rs+208>: 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c
0x55a725956000 <rs+224>: 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c
0x55a725956010 <rs+240>: 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c 0x6c6c6c6c
0x55a725956020 <rs+256>: 0x00006c6c 0x00000983 0x0000a1e0 0x00000000

It should not look like this, seems that it has not been initialized, please verify this.

(gdb) x/256cx rs.s
0x5555556eae82 <rs+2>:  0x73    0x6c    0x5b    0x07    0x78    0x19    0x26    0xf6
0x5555556eae8a <rs+10>: 0x70    0x3c    0xfc    0x2c    0xbd    0xae    0xe3    0x48
0x5555556eae92 <rs+18>: 0xd8    0x97    0xe8    0xff    0xa9    0xdf    0xb5    0x81
0x5555556eae9a <rs+26>: 0x8e    0x02    0x45    0x7b    0x33    0x90    0xac    0x82
0x5555556eaea2 <rs+34>: 0x38    0x83    0xd9    0x91    0x7f    0x40    0x8c    0xbf
0x5555556eaeaa <rs+42>: 0x54    0x25    0xbe    0xb1    0x43    0xcf    0x2b    0x0b
0x5555556eaeb2 <rs+50>: 0x44    0xd0    0x5e    0x4b    0x98    0x27    0x4f    0xf1
0x5555556eaeba <rs+58>: 0x49    0x00    0xe7    0x23    0x3b    0xda    0x66    0xd2
0x5555556eaec2 <rs+66>: 0x94    0x08    0x57    0x5a    0xa0    0x03    0x74    0xbc
0x5555556eaeca <rs+74>: 0x71    0xce    0x2d    0x5c    0x64    0x75    0x51    0x16
0x5555556eaed2 <rs+82>: 0x41    0x14    0xc1    0x47    0xaf    0x77    0x69    0x1a
0x5555556eaeda <rs+90>: 0x12    0xc4    0xb4    0xa7    0x9d    0x11    0x8f    0x1b
0x5555556eaee2 <rs+98>: 0xe2    0xa8    0x9e    0x7d    0x59    0x1f    0x55    0x53
0x5555556eaeea <rs+106>:        0x61    0xa2    0xa6    0x4a    0xee    0x50    0x58    0x2a
0x5555556eaef2 <rs+114>:        0x4e    0x2e    0xef    0x63    0x24    0x0e    0x22    0x1e
0x5555556eaefa <rs+122>:        0xd5    0x9a    0x31    0x72    0x80    0xb2    0x52    0xf3
0x5555556eaf02 <rs+130>:        0xfd    0x92    0x37    0xc0    0x8a    0x9b    0x56    0x89
0x5555556eaf0a <rs+138>:        0xe5    0x20    0x86    0xed    0x18    0xad    0x6f    0x6a
0x5555556eaf12 <rs+146>:        0x68    0x0d    0x30    0xf5    0xd6    0xfe    0xe1    0x35
0x5555556eaf1a <rs+154>:        0xf8    0x0c    0x10    0x60    0x3a    0x7a    0xd1    0x7e
0x5555556eaf22 <rs+162>:        0x5f    0xd7    0xb9    0x21    0xdd    0xd4    0xc5    0x96
0x5555556eaf2a <rs+170>:        0x79    0xf7    0xdc    0x04    0x06    0xcb    0x32    0xcc
0x5555556eaf32 <rs+178>:        0xe9    0xc7    0x2f    0x4c    0x9c    0x62    0xa1    0x6b
0x5555556eaf3a <rs+186>:        0xca    0xa4    0xf0    0xb0    0xc2    0x1d    0x6d    0x76
0x5555556eaf42 <rs+194>:        0xea    0xe4    0xeb    0x17    0x46    0xb6    0xf4    0x05
0x5555556eaf4a <rs+202>:        0x88    0x4d    0xfa    0x39    0xde    0x9f    0xd3    0x34
0x5555556eaf52 <rs+210>:        0x84    0xab    0x3d    0x42    0x28    0x09    0x6e    0xc3
0x5555556eaf5a <rs+218>:        0xb3    0xec    0x85    0xdb    0x3f    0xc8    0xe0    0xe6
0x5555556eaf62 <rs+226>:        0x3e    0x65    0xc6    0x13    0x29    0x8d    0xb7    0xcd
0x5555556eaf6a <rs+234>:        0xb8    0x0f    0x87    0x7c    0xf9    0xbb    0xa5    0x1c
0x5555556eaf72 <rs+242>:        0xba    0x67    0x8b    0x5d    0x15    0x01    0xfb    0x99
0x5555556eaf7a <rs+250>:        0xa3    0xaa    0x0a    0xf2    0x93    0x95    0x36    0xc9

arc4random_buf(void *buf_, size_t n)
{
unsigned char *buf = buf_;
ARC4_LOCK_();
arc4_stir_if_needed();
while (n--) {
if (--arc4_count <= 0)
arc4_stir();
buf[n] = arc4_getbyte();
}
ARC4_UNLOCK_();
}

arc4_stir_if_needed will initialize rs

Hello!

Have you enabled multi-thread support for libevent?

evthread_use_pthreads()

Or

evthread_use_windows_threads()

If yes, can you please try one of the following to get more details?

• compile libevent and your program with clang -fsanitize=address,undefined
• compile libevent and your program with clang -fsanitize=thread,undefined

And something less preferable but easier:

• run under valgrind --tool=memcheck
• run under valgrind --tool=drd or valgrind --tool=helgrind

Hi Azat, I think you are right. We used multi-thread, but every thread will have its own event loop, so I think we do not need evthread_use_pthreads(). But rs in libevent is a global variable, if several threads write it at the same time, it will be corrupted. I will close this issue