Messages in this thread | | | From | Daniel Gollub <> | Subject | Re: [patch 0/3] [RFC] kernel/glibc mismatch of "readlink" syscall? | Date | Fri, 31 Oct 2008 16:37:23 +0100 |
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On Friday 31 October 2008 16:02:48 Kai Henningsen wrote: > Am Fri, 24 Oct 2008 17:53:25 -0500 > > schrieb "Michael Kerrisk" <mtk.manpages@googlemail.com>: > > Hi Daniel, > > > > On Thu, Oct 23, 2008 at 9:50 AM, Daniel Gollub <dgollub@suse.de> > > > > wrote: > > > EINVAL bufsiz is not positive. > > > > The EINVAL error was added to man-pages-1.18 in 1997 (even though, as > > you note, the type was "size_t"). I suspect (this was well before I > > had any association with man-pages) that was done to reflect kernel > > reality (since one could bypass glibc invoke the syscall directly), > > but obviously it is inconsistent with the prototype. > > Actually, it's not inconsistent as described, though perhaps that is > unintentional. "Not positive" isn't the same as "negative", as zero > isn't positive either, and zero is certainly a possible value of an > unsigned type
True.
But there is still the problem for the ltp syscall test "readlink03", when using the glibc "readlink" interface, by calling readlink with a buffer size of "-1".
Calling "-1" seems to be a valid code/error-path in the linux syscall "readlink", since there is a check for less-equal zero.
But the less zero, condition can't be reached via the glibc "readlink" interface since this would cause fortify-check to fail (when buliding with - D_FORITFY_SOURCE=2).
To "workaround" the fortify check, by not compiling the testcase with - D_FORTIFY_SOURCE=2, or trying to test the linux readlink interface by calling directly syscall() in the testcase ... both suggestion are just workarounds - no real solutions.
We could also just remove the testcase of buffer size "-1".
The problem is still, how to test the "readlink" syscall in LTP?
best regards, Daniel -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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