Re: Return type of getrandom(2)

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Sat, Oct 08, 2016 at 02:28:27PM +0200, Florian Weimer wrote:
> The manual page says the return type of getrandom(2) is int, but
> ssize_t would be more natural (see read(2) for comparison).  The
> kernel uses ssize_t internally, which is converted to long on the
> system call boundary.
> 
> The difference does not currently matter because the return value is
> limited to much less than INT_MAX in the implementation.
> 
> Should we use int or ssize_t in the glibc system call wrapper?

I'd suggest keeping it as an int since (a) OpenBSD's getentropy(2)
returns an int, and part of the orignal design goal is to be able to
emulate OpenBSD's getentropy(2) system call via:

int getentropy(void *buf, size_t buflen)
{
	return getrandom(buf, buflen, 0);
}

and (b) the maximum number of bytes returned will *always* be well
under INT_MAX.  I can't forsee at any point in any future or alternate
universe where getrandom() would need to return anywhere near
SHORT_MAX, let alone INT_MAX.

Cheers,

					- Ted






--
To unsubscribe from this list: send the line "unsubscribe linux-man" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Kernel Documentation]     [Netdev]     [Linux Ethernet Bridging]     [Linux Wireless]     [Kernel Newbies]     [Security]     [Linux for Hams]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux RAID]     [Linux Admin]     [Samba]

  Powered by Linux