ubuntu@ubuntu:~/rdrand-test$ telegram-desktop
WARNING: CPU random generator seem to be failing, disabling hardware random number generation
WARNING: RDRND generated: 0xffffffff 0xffffffff 0xffffffff 0xffffffff
(telegram-desktop:7811): dbind-WARNING **: 16:22:53.032: Couldn't register with accessibility bus: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.
=========
ubuntu@ubuntu:~/rdrand-test$ ./amd-rdrand-bug
Your RDRAND() returns -1 every time, which means it has the AMD bug.
=========
ubuntu@ubuntu:~/rdrand-test$ cat amd-rdrand-bug.c
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*
* Compile: `gcc -o amd-rdrand-bug -O3 -mrdrnd -std=gnu99 amd-rdrand-bug.c`
*/
#include <stdio.h>
#include <stdint.h>
#include <immintrin.h>
int main(int argc, char *argv[])
{ for (int j, i = 0; i < 2000; ++i) { for (j = 0; j < 100; ++j) { uint32_t val = 0;
if (__builtin_ia32_rdrand32_step(&val)) { if (val != 0xffffffffU) { puts("Your RDRAND() does not have the AMD bug."); return 0;
}
break;
}
}
if (j == 100) { puts("Failed to sample your RDRAND()."); return 1;
}
}
puts("Your RDRAND() returns -1 every time, which means it has the AMD bug."); return 1;
}
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https://arstechnica.com/gadgets/2019/10/how-a-months-old-amd-microcode-bug-destroyed-my-weekend/