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Merge branch 'kcsan' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into locking/core

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Pull KCSAN updates for v5.10 from Paul E. McKenney:

 - Improve kernel messages.

 - Be more permissive with bitops races under KCSAN_ASSUME_PLAIN_WRITES_ATOMIC=y.

 - Optimize debugfs stat counters.

 - Introduce the instrument_*read_write() annotations, to provide a
   finer description of certain ops - using KCSAN's compound instrumentation.
   Use them for atomic RNW and bitops, where appropriate.
   Doing this might find new races.
   (Depends on the compiler having tsan-compound-read-before-write=1 support.)

 - Support atomic built-ins, which will help certain architectures, such as s390.

 - Misc enhancements and smaller fixes.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Ingo Molnar
2020-10-09 08:35:01 +02:00
parent e705d39796 cd290ec246
commit d6c4c11348
16 changed files with 677 additions and 347 deletions
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2
scripts/Makefile.kcsan
View File

@@ -11,5 +11,5 @@ endif
# of some options does not break KCSAN nor causes false positive reports.
CFLAGS_KCSAN := -fsanitize=thread \
$(call cc-option,$(call cc-param,tsan-instrument-func-entry-exit=0) -fno-optimize-sibling-calls) \
$(call cc-option,$(call cc-param,tsan-instrument-read-before-write=1)) \
$(call cc-option,$(call cc-param,tsan-compound-read-before-write=1),$(call cc-option,$(call cc-param,tsan-instrument-read-before-write=1))) \
$(call cc-param,tsan-distinguish-volatile=1)

21
scripts/atomic/gen-atomic-instrumented.sh
View File

@@ -5,9 +5,10 @@ ATOMICDIR=$(dirname $0)
. ${ATOMICDIR}/atomic-tbl.sh
#gen_param_check(arg)
#gen_param_check(meta, arg)
gen_param_check()
{
local meta="$1"; shift
local arg="$1"; shift
local type="${arg%%:*}"
local name="$(gen_param_name "${arg}")"
@@ -17,17 +18,25 @@ gen_param_check()
i) return;;
esac
# We don't write to constant parameters
[ ${type#c} != ${type} ] && rw="read"
if [ ${type#c} != ${type} ]; then
# We don't write to constant parameters.
rw="read"
elif [ "${meta}" != "s" ]; then
# An atomic RMW: if this parameter is not a constant, and this atomic is
# not just a 's'tore, this parameter is both read from and written to.
rw="read_write"
fi
printf "\tinstrument_atomic_${rw}(${name}, sizeof(*${name}));\n"
}
#gen_param_check(arg...)
#gen_params_checks(meta, arg...)
gen_params_checks()
{
local meta="$1"; shift
while [ "$#" -gt 0 ]; do
gen_param_check "$1"
gen_param_check "$meta" "$1"
shift;
done
}
@@ -77,7 +86,7 @@ gen_proto_order_variant()
local ret="$(gen_ret_type "${meta}" "${int}")"
local params="$(gen_params "${int}" "${atomic}" "$@")"
local checks="$(gen_params_checks "$@")"
local checks="$(gen_params_checks "${meta}" "$@")"
local args="$(gen_args "$@")"
local retstmt="$(gen_ret_stmt "${meta}")"