Messages in this thread | | | Date | Thu, 28 Aug 2014 15:32:43 +0100 | From | Al Viro <> | Subject | Re: [PATCH v2] fs: namespace: suppress 'may be used uninitialized' warnings |
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On Thu, Aug 28, 2014 at 07:55:49AM -0600, rtg.canonical@gmail.com wrote: > From: Tim Gardner <tim.gardner@canonical.com> > > The gcc version 4.9.1 compiler complains even though it isn't possible for > these variables to not get initialized before they are used.
Sigh... The root cause of that shite is that copy_mount_string() is too convoluted for gcc (piss-poor) detection of uninitialized variables. And yes, it is somewhat overcomplicated - it returns 0 or -E... *and* in former case it returns NULL or a string as well, via a char ** argument.
The usual convention for such suckers is "return a pointer, using ERR_PTR(-E...) to indicate an error". We have all of 4 (four) callers, all in fs/*.c (and nobody else could see that function, unless they manually included fs/internal.h).
So let's turn that into char *copy_mount_string(const void __user *data) { return data ? strndup_user(data, PAGE_SIZE) : NULL; }
and uses of that thing into kernel_type = copy_mount_string(type); ret = PTR_ERR(kernel_type); if (IS_ERR(kernel_type)) goto out_type; etc.
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