On Tue, Jan 19, 2016 at 03:09:14PM +0100, Arnd Bergmann wrote:

On Tuesday 19 January 2016 13:37:50 James Hogan wrote:

quoted

When a header file is removed from generic-y (often accompanied by the
addition of an arch specific header), the generated wrapper file will
persist, and in some cases may still take precedence over the new arch
header.

For example commit f1fe2d21f4e1 ("MIPS: Add definitions for extended
context") removed ucontext.h from generic-y in arch/mips/include/asm/,
and added an arch/mips/include/uapi/asm/ucontext.h. The continued use of
the wrapper when reusing a dirty build tree resulted in build failures
in arch/mips/kernel/signal.c:

arch/mips/kernel/signal.c: In function ‘sc_to_extcontext’:
arch/mips/kernel/signal.c:142:12: error: ‘struct ucontext’ has no member named ‘uc_extcontext’
  return &uc->uc_extcontext;
            ^

Fix by detecting and removing wrapper headers in generated header
directories that do not correspond to a filename in generic-y, genhdr-y,
or the newly introduced generated-y.

Good idea.

Acked-by: Arnd Bergmann <arnd@arndb.de>

Thanks Arnd

Can you merge this through the mips tree, or do you need me to pick it
up through asm-generic?

I was envisaging the kbuild tree tbh, but I don't really mind how it
gets merged. This patch depends on patch 1, which adds generated-y to
x86 so we don't delete their other generated headers, but other than
that it doesn't really have any dependencies.

Cheers
James