kcov: fix generic Kconfig dependencies if ARCH_WANTS_NO_INSTR
Until recent versions of GCC and Clang, it was not possible to disable
KCOV instrumentation via a function attribute. The relevant function
attribute was introduced in
dd459503f218d ("kcov: add
__no_sanitize_coverage to fix noinstr for all architectures").
x86 was the first architecture to want a working noinstr, and at the
time no compiler support for the attribute existed yet. Therefore,
commit
f5270568b23ee ("objtool: Fix noinstr vs KCOV") introduced the
ability to NOP __sanitizer_cov_*() calls in .noinstr.text.
However, this doesn't work for other architectures like arm64 and s390
that want a working noinstr per ARCH_WANTS_NO_INSTR.
At the time of
f5270568b23ee, we didn't yet have ARCH_WANTS_NO_INSTR,
but now we can move the Kconfig dependency checks to the generic KCOV
option. KCOV will be available if:
- architecture does not care about noinstr, OR
- we have objtool support (like on x86), OR
- GCC is 12.0 or newer, OR
- Clang is 13.0 or newer.
Link: https://lkml.kernel.org/r/20211201152604.3984495-1-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>