[PATCH v2] [PATCH] KEYS: trusted: fix -Wvarags warning

Jarkko Sakkinen jarkko.sakkinen at linux.intel.com
Thu Feb 14 10:52:21 UTC 2019


On Wed, Feb 13, 2019 at 01:12:56AM +0200, Jarkko Sakkinen wrote:
> On Mon, Feb 11, 2019 at 10:36:51AM -0800, Nick Desaulniers wrote:
> > On Mon, Oct 29, 2018 at 10:54 AM Nick Desaulniers
> > <ndesaulniers at google.com> wrote:
> > >
> > > On Wed, Oct 24, 2018 at 1:37 AM Jarkko Sakkinen
> > > <jarkko.sakkinen at linux.intel.com> wrote:
> > > >
> > > > On Mon, 22 Oct 2018, ndesaulniers at google.com wrote:
> > > > > Fixes the warning reported by Clang:
> > > > > security/keys/trusted.c:146:17: warning: passing an object that
> > > > > undergoes default
> > > > >      argument promotion to 'va_start' has undefined behavior [-Wvarargs]
> > > > >        va_start(argp, h3);
> > > > >                       ^
> > > > > security/keys/trusted.c:126:37: note: parameter of type 'unsigned
> > > > > char' is declared here
> > > > > unsigned char *h2, unsigned char h3, ...)
> > > > >                               ^
> > > > > Specifically, it seems that both the C90 (4.8.1.1) and C11 (7.16.1.4)
> > > > > standards explicitly call this out as undefined behavior:
> > > > >
> > > > > The parameter parmN is the identifier of the rightmost parameter in
> > > > > the variable parameter list in the function definition (the one just
> > > > > before the ...). If the parameter parmN is declared with ... or with a
> > > > > type that is not compatible with the type that results after
> > > > > application of the default argument promotions, the behavior is
> > > > > undefined.
> > > > >
> > > > > Link: https://github.com/ClangBuiltLinux/linux/issues/41
> > > > > Link: https://www.eskimo.com/~scs/cclass/int/sx11c.html
> > > > > Suggested-by: David Laight <David.Laight at aculab.com>
> > > > > Suggested-by: Denis Kenzior <denkenz at gmail.com>
> > > > > Suggested-by: James Bottomley <jejb at linux.vnet.ibm.com>
> > > > > Suggested-by: Nathan Chancellor <natechancellor at gmail.com>
> > > > > Signed-off-by: Nick Desaulniers <ndesaulniers at google.com>
> > > >
> > > > Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen at linux.intel.com>
> > > >
> > > > /Jarkko
> > >
> > > Bumping the maintainers if this isn't already picked up?
> > 
> > James, Jarkko, or Mimi, can you please pick this up (and let me know
> > what tree it lands in)?
> 
> I can volunteer. Have not done yet v5.1 PR so it would land to that
> release. Is this agreed?

http://git.infradead.org/users/jjs/linux-tpmdd.git/commit/cfb1f7ee3b35e6ba9e9e2de53a8668ced6397f88

/Jarkko



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