Similarly to type mismatch checks, new GCC 8.x and Clang also changed for
ABI for returns_nonnull checks. While we can update our code to conform
the new ABI it's more reasonable to just remove it. Because it's just
dead code, we don't have any single user of returns_nonnull attribute in
the whole kernel.
And AFAIU the advantage that this attribute could bring would be mitigated
by -fno-delete-null-pointer-checks cflag that we use to build the kernel.
So it's unlikely we will have a lot of returns_nonnull attribute in
future.
So let's just remove the code, it has no use.
[aryabinin@virtuozzo.com: fix warning]
Link: http://lkml.kernel.org/r/20180122165711.11510-1-aryabinin@virtuozzo.com
Link: http://lkml.kernel.org/r/20180119152853.16806-2-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Sodagudi Prasad <psodagud@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
UBSAN=y fails to build with new GCC/clang:
arch/x86/kernel/head64.o: In function `sanitize_boot_params':
arch/x86/include/asm/bootparam_utils.h:37: undefined reference to `__ubsan_handle_type_mismatch_v1'
because Clang and GCC 8 slightly changed ABI for 'type mismatch' errors.
Compiler now uses new __ubsan_handle_type_mismatch_v1() function with
slightly modified 'struct type_mismatch_data'.
Let's add new 'struct type_mismatch_data_common' which is independent from
compiler's layout of 'struct type_mismatch_data'. And make
__ubsan_handle_type_mismatch[_v1]() functions transform compiler-dependent
type mismatch data to our internal representation. This way, we can
support both old and new compilers with minimal amount of change.
Link: http://lkml.kernel.org/r/20180119152853.16806-1-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reported-by: Sodagudi Prasad <psodagud@codeaurora.org>
Cc: <stable@vger.kernel.org> [4.5+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>