x86/build: Use cc-option to validate stack alignment parameter

With the following commit:

  8f91869766c0 ("x86/build: Fix stack alignment for CLang")

cc-option is only used to determine the name of the stack alignment option
supported by the compiler, but not to verify that the actual parameter
<option>=N is valid in combination with the other CFLAGS.

This causes problems (as reported by the kbuild robot) with older GCC versions
which only support stack alignment on a boundary of 16 bytes or higher.

Also use (__)cc_option to add the stack alignment option to CFLAGS to
make sure only valid options are added.

Reported-by: kbuild test robot <[email protected]>
Signed-off-by: Matthias Kaehlcke <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: [email protected]
Cc: Greg Hackmann <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Masahiro Yamada <[email protected]>
Cc: Michael Davidson <[email protected]>
Cc: Nick Desaulniers <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephen Hines <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Fixes: 8f91869766c0 ("x86/build: Fix stack alignment for CLang")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

0 files changed, 0 insertions, 0 deletions