add `linux-headers/arch/arm64` since we only have `x86`

[vogler]

On Apple M1 many regression tests fail due to the wrongly used x86 headers:

goblint/analyzer/linux-headers/arch/x86/include/asm/pvclock.h:56:2: error: #error implement me!
  -    56 | #error implement me!
  -       |  ^~~~~
  - Goblint: Preprocessing failed.

pvclock.h:

#ifdef __i386__
	__asm__ (
		"mul  %5       ; "
		"mov  %4,%%eax ; "
		"mov  %%edx,%4 ; "
		"mul  %5       ; "
		"xor  %5,%5    ; "
		"add  %4,%%eax ; "
		"adc  %5,%%edx ; "
		: "=A" (product), "=r" (tmp1), "=r" (tmp2)
		: "a" ((u32)delta), "1" ((u32)(delta >> 32)), "2" (mul_frac) );
#elif defined(__x86_64__)
	__asm__ (
		"mulq %[mul_frac] ; shrd $32, %[hi], %[lo]"
		: [lo]"=a"(product),
		  [hi]"=d"(tmp)
		: "0"(delta),
		  [mul_frac]"rm"((u64)mul_frac));
#else
#error implement me!
#endif

I think these headers are pretty old, maybe it's also a good idea to update them.

[michael-schwarz]

maybe it's also a good idea to update them.

If CIL can parse the newer ones, absolutely!

[vogler]

@vesalvojdani I tried to use a newer kernel, but config fails on my machine:

$ mv linux-headers linux-headers-old
$ wget https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.14.2.tar.xz
$ tar xf linux-5.14.2.tar.xz
$ mv linux-5.14.2 linux-headers
$ make test
Testing 00/14 sanity/startstate	 Status: 1 (error)
  - /Users/voglerr/goblint/analyzer/linux-headers/include/linux/kconfig.h:5:10: fatal error: generated/autoconf.h: No such file or directory
  -     5 | #include <generated/autoconf.h>
  -       |          ^~~~~~~~~~~~~~~~~~~~~~
  - compilation terminated.
  - Goblint: Preprocessing failed.
$ cd linux-headers
$ make
***
*** Configuration file ".config" not found!
***
*** Please run some configurator (e.g. "make oldconfig" or
*** "make menuconfig" or "make xconfig").
***
$ make menuconfig
gcc -no-integrated-as --prefix= -Werror=unknown-warning-option: unknown assembler invoked
scripts/Kconfig.include:50: Sorry, this assembler is not supported.
make[2]: *** [menuconfig] Error 1
make[1]: *** [menuconfig] Error 2
make: *** [__sub-make] Error 2
$ cp ../linux-headers-old/config.txt .config
$ make oldconfig
gcc -no-integrated-as --prefix= -Werror=unknown-warning-option: unknown assembler invoked
scripts/Kconfig.include:50: Sorry, this assembler is not supported.

[sim642]

I think @vesalvojdani tried something (on non-M1 Mac I guess), but then found out that newer kernels use some C11 features like _Generic, which CIL (and Goblint) don't currently support (goblint/cil#13, goblint/cil#24).

[vogler]

We can also use an older version (our config.txt says Linux/x86 4.0.0), but idk if the introduction of those C11 features happened before arch/arm64 was added.

[vogler]

Also tried make headers_install ARCH=arm64 INSTALL_HDR_PATH=usr (doc) which needs no config, but that's not enough: analyzer/linux-headers/include/linux/kconfig.h: No such file or directory.

[vogler]

analyzer/src/maingoblint.ml

Line 171 in c3932dc

let arch_dir = kernel_root ^ "/arch/x86/include" in

This (and #54) would then be determined by an option arch defaulting to the current machine's arch.