linux-kernel - Unkillable gdb process gets system unusably slow

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <1195793695.3843.7.camel@hurina>
Date:	Fri, 23 Nov 2007 06:54:55 +0200
From:	Timo Sirainen <tss@....fi>
To:	linux-kernel@...r.kernel.org
Subject: Unkillable gdb process gets system unusably slow

Fully reproducible with me. v2.6.23.1 x86-64 SMP kernel, Core 2 CPU, gdb
v6.6.90.20070912-debian.

gdb ./hang
run
fr 1
p (char*)base

p command hangs and the entire system becomes unusably slow. kill -9
doesn't kill gdb.

/* gcc hang.c -o hang -g -Wall */
#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/mman.h>

int main(void)
{
	int fd;
	char buf[100];
	void *base;

	fd = open("hang.tmp", O_RDWR | O_CREAT, 0600);
	if (fd == -1) perror("open");

	base = mmap(NULL, 100, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
	if (base == MAP_FAILED)
		perror("mmap");
	memcpy(buf, base, sizeof(buf));
	return 0;
}


Download attachment "signature.asc" of type "application/pgp-signature" (190 bytes)