The patch titled
Subject: kcov: ignore fault-inject and stacktrace
has been added to the -mm tree. Its filename is
kcov-ignore-fault-inject-and-stacktrace.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/kcov-ignore-fault-inject-and-stacktrace.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/kcov-ignore-fault-inject-and-stacktrace.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
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@xxxxxxxxx
Signed-off-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Reviewed-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
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@xxxxxxxxxx are
kcov-ignore-fault-inject-and-stacktrace.patch
