On Wednesday 07 August 2013 03:01:26 Jiri Kosina wrote:
> On Tue, 6 Aug 2013, Peter Wu wrote:
> > While debugging upowerd (with Logitech Unifying receiver via hidraw),
> > I came across this list corruption warning.
>
> Peter,
>
> does the patch below fix the problem you are seeing?
That one is already in 3.11-rc4 as far as I can see. Also, that code can
probably simplified by moving the mutex_unlock after the out label, removing
the need to duplicate the mutex_unlock.
Remember what I said about "no Oopses"? Well, it turned out that several
memory structures were damaged which causes a general protection fault in
sock_alloc_inode and other places.
I managed to create a program that can reproduce this bug 100% in a QEMU
virtual machine with a Logitech USB receiver passed to it.
qemu-system-x86_64 -enable-kvm -m 1G -usb -usbdevice host:046d:c52b
(pass -kernel, -initrd, -append as needed)
Copy hidraw-test to initrd, boot QEMU and run `hidraw-test`. Result: instant
(= +/- 2 seconds) crash.
I have applied Manoj's patch[1] on top of 3.11-rc4 which seem to fix the issue.
One observation is that the new device is named /dev/hidraw1 instead of
/dev/hidraw0. Example:
f(){ hidraw-test /dev/hidraw$1 usb1;}
# needed for 3.11-rc4
f 1; f 1 # crash
# needed for 3.11-rc4 + patch
f 1; f 2 # ok
Regards,
Peter
[1]: http://lkml.org/lkml/2013/7/22/248
--
/* cc hidraw-test.c -o hidraw-test
* hidraw-test /dev/hidraw0 usb1; hidraw-test /dev/hidraw0 usb1;
*/
#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
int open_and_write(const char *path, const char *data) {
int sfd, r;
sfd = open(path, O_WRONLY);
if (sfd < 0) {
perror(path);
return 1;
}
r = write(sfd, data, strlen(data));
if (r < 0) {
fprintf(stderr, "write(%s, %s): %s\n",
path, data, strerror(errno));
return 1;
}
close(sfd);
return 0;
}
int dork(const char *hiddev, const char *name) {
int fd;
char c;
fd = open(hiddev, O_RDWR | O_NONBLOCK);
if (fd < 0) {
perror("open");
return 1;
}
if (open_and_write("/sys/bus/usb/drivers/usb/unbind", name))
return 1;
// does not make a difference
//sleep(1);
if (open_and_write("/sys/bus/usb/drivers/usb/bind", name))
return 1;
// allow devices to get discovered
sleep(1);
printf("read() = %zi\n", read(fd, &c, 1)); perror("read");
close(fd);
return 0;
}
int main(int argc, char **argv) {
if (argc < 3) {
fprintf(stderr, "Usage: %s /dev/hidrawN usbN\n", *argv);
return 1;
}
system("modprobe -v usbhid");
system("modprobe -v hid-logitech-dj");
dork(argv[1], argv[2]);
return 0;
}
--
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