From mboxrd@z Thu Jan 1 00:00:00 1970 From: akpm@linux-foundation.org Subject: [merged] kcov-ignore-fault-inject-and-stacktrace.patch removed from -mm tree Date: Fri, 31 Jan 2020 15:21:13 -0800 Message-ID: <20200131232113.53H-DdXVY%akpm@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.99]:52772 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726319AbgAaXVP (ORCPT ); Fri, 31 Jan 2020 18:21:15 -0500 Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: andreyknvl@google.com, dvyukov@google.com, mm-commits@vger.kernel.org The patch titled Subject: kcov: ignore fault-inject and stacktrace has been removed from the -mm tree. Its filename was kcov-ignore-fault-inject-and-stacktrace.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Dmitry Vyukov Subject: kcov: ignore fault-inject and stacktrace Don't instrument 3 more files that contain debugging facilities and produce large amounts of uninteresting coverage for every syscall. The following snippets are sprinkled all over the place in kcov traces in a debugging kernel. We already try to disable instrumentation of stack unwinding code and of most debug facilities. I guess we did not use fault-inject.c at the time, and stacktrace.c was somehow missed (or something has changed in kernel/configs). This change both speeds up kcov (kernel doesn't need to store these PCs, user-space doesn't need to process them) and frees trace buffer capacity for more useful coverage. should_fail lib/fault-inject.c:149 fail_dump lib/fault-inject.c:45 stack_trace_save kernel/stacktrace.c:124 stack_trace_consume_entry kernel/stacktrace.c:86 stack_trace_consume_entry kernel/stacktrace.c:89 ... a hundred frames skipped ... stack_trace_consume_entry kernel/stacktrace.c:93 stack_trace_consume_entry kernel/stacktrace.c:86 Link: http://lkml.kernel.org/r/20200116111449.217744-1-dvyukov@gmail.com Signed-off-by: Dmitry Vyukov Reviewed-by: Andrey Konovalov Signed-off-by: Andrew Morton --- kernel/Makefile | 1 + lib/Makefile | 1 + mm/Makefile | 1 + 3 files changed, 3 insertions(+) --- a/kernel/Makefile~kcov-ignore-fault-inject-and-stacktrace +++ a/kernel/Makefile @@ -27,6 +27,7 @@ KCOV_INSTRUMENT_softirq.o := n # and produce insane amounts of uninteresting coverage. KCOV_INSTRUMENT_module.o := n KCOV_INSTRUMENT_extable.o := n +KCOV_INSTRUMENT_stacktrace.o := n # Don't self-instrument. KCOV_INSTRUMENT_kcov.o := n KASAN_SANITIZE_kcov.o := n --- a/lib/Makefile~kcov-ignore-fault-inject-and-stacktrace +++ a/lib/Makefile @@ -16,6 +16,7 @@ KCOV_INSTRUMENT_rbtree.o := n KCOV_INSTRUMENT_list_debug.o := n KCOV_INSTRUMENT_debugobjects.o := n KCOV_INSTRUMENT_dynamic_debug.o := n +KCOV_INSTRUMENT_fault-inject.o := n # Early boot use of cmdline, don't instrument it ifdef CONFIG_AMD_MEM_ENCRYPT --- a/mm/Makefile~kcov-ignore-fault-inject-and-stacktrace +++ a/mm/Makefile @@ -20,6 +20,7 @@ KCOV_INSTRUMENT_kmemleak.o := n KCOV_INSTRUMENT_memcontrol.o := n KCOV_INSTRUMENT_mmzone.o := n KCOV_INSTRUMENT_vmstat.o := n +KCOV_INSTRUMENT_failslab.o := n CFLAGS_init-mm.o += $(call cc-disable-warning, override-init) CFLAGS_init-mm.o += $(call cc-disable-warning, initializer-overrides) _ Patches currently in -mm which might be from dvyukov@google.com are