x86/purgatory: Avoid creating stray .<pid>.d files, remove -MD from KBUILD_CFLAGS

The kernel build system already takes care of generating the dependency
files. Having the additional -MD in KBUILD_CFLAGS leads to stray
.<pid>.d files in the build directory when we call the cc-option macro.

Signed-off-by: Sven Wegener <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Matthias Kaehlcke <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Sam Ravnborg <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vivek Goyal <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

Author: swegener

arch/x86/purgatory/Makefile

@@ -16,7 +16,7 @@ KCOV_INSTRUMENT := n
 # in turn leaves some undefined symbols like __fentry__ in purgatory and not
 # sure how to relocate those. Like kexec-tools, use custom flags.
 
-KBUILD_CFLAGS := -fno-strict-aliasing -Wall -Wstrict-prototypes -fno-zero-initialized-in-bss -fno-builtin -ffreestanding -c -MD -Os -mcmodel=large
+KBUILD_CFLAGS := -fno-strict-aliasing -Wall -Wstrict-prototypes -fno-zero-initialized-in-bss -fno-builtin -ffreestanding -c -Os -mcmodel=large
 KBUILD_CFLAGS += -m$(BITS)
 KBUILD_CFLAGS += $(call cc-option,-fno-PIE)