Bug #6427: ruby ioctl: Error integer 2148012656 too big to convert to `int'

• Status: Rejected
• Assignee: -
• Target version: -
• ruby -v: ruby 1.8.7 (2011-06-30 patchlevel 352) [x86_64-linux]

[hadmut (Hadmut Danisch)]

Hi,

the upgrade to ubuntu 12.04 came with an upgrade to ruby 1.9.3.
Unfortunately, in recent 1.9.3 versions of ruby there's a bug in the
ioctl function. E.g. if you want to do getbsz() on a block device and do
a

f.ioctl(0x80081270,a)

you'll get the error message

Error integer 2148012656 too big to convert to `int'
RangeError

(2148012656 = 0x80081270)

So ruby can't do ioctl's anymore if the highest bit is set in the ioctl code.

This was working code in ruby 1.9.2 / ubuntu 11.10.

regards

[shyouhei (Shyouhei Urabe)]

• Status changed from Open to Rejected

Both ruby and glibc header file (and Ubuntu's manpage of ioctl(2)) agree that
ioctl takes int, and 2148012656 is greater than INT_MAX. Hence the exception.

You have to use -2146954640 instead.

[naruse (Yui NARUSE)]

shyouhei (Shyouhei Urabe) wrote:

Both ruby and glibc header file (and Ubuntu's manpage of ioctl(2)) agree that
ioctl takes int, and 2148012656 is greater than INT_MAX. Hence the exception.

You have to use -2146954640 instead.

The manpage of ioctl(2) says that the type of its 2nd argument is int, but it is a lie.
The prototype of ioctl(2) in /usr/include/sys/ioctl.h says it is unsigned int.
extern int ioctl (int __fd, unsigned long int __request, ...) __THROW;

Bug #5429 is the issue and it says:

• Free Unix uses unsigned int
• Commercial Unix uses int

This issue is fixed in trunk but not backported to 1.9.3 yet.

[shyouhei (Shyouhei Urabe)]

Oh, I didn't know that. Thank you to point that out.

[kosaki (Motohiro KOSAKI)]

On Sat, May 12, 2012 at 11:23 AM, naruse (Yui NARUSE) [e-mail] wrote:

Issue #6427 has been updated by naruse (Yui NARUSE).

shyouhei (Shyouhei Urabe) wrote:

Both ruby and glibc header file (and Ubuntu's manpage of ioctl(2)) agree that
ioctl takes int, and 2148012656 is greater than INT_MAX.  Hence the exception.

You have to use -2146954640 instead.

The manpage of ioctl(2) says that the type of its 2nd argument is int, but it is a lie.
The prototype of ioctl(2) in /usr/include/sys/ioctl.h says it is unsigned int.
extern int ioctl (int __fd, unsigned long int __request, ...) __THROW;

Bug #5429 is the issue and it says:

• Free Unix uses unsigned int
• Commercial Unix uses int

This issue is fixed in trunk but not backported to 1.9.3 yet.

btw, Linux community plan to fix man pages too.

https://bugzilla.kernel.org/show_bug.cgi?id=42705