test/common: don't specify output dir for core_pattern in command line

Remove output directory argument for core-collector.sh when
setting system core_pattern. Instead save the full output
directory path into a file to a known location and read it
directly in core-collector.sh.

The reason for this change is 128 bytes command line length
for core_pattern (see 'man core 5'). In case working with
long paths the core_pattern command line gets truncated and
core dumps are not generated.

Change-Id: Ia74c180e4923fb43d6ff66129ffe54c32827adca
Signed-off-by: Karol Latecki <[email protected]>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/12755
Community-CI: Broadcom CI <[email protected]>
Tested-by: SPDK CI Jenkins <[email protected]>
Reviewed-by: Michal Berger <[email protected]>
Reviewed-by: Pawel Piatek <[email protected]>
Reviewed-by: Konrad Sztyber <[email protected]>
Reviewed-by: Jim Harris <[email protected]>

.gitignore

@@ -39,3 +39,4 @@ PYTHON_COMMAND
 test_completions.txt
 timing.txt
 test/common/build_config.sh
+.coredump_path

autotest.sh

@@ -28,8 +28,12 @@ fi
 if [ $(uname -s) = Linux ]; then
 	old_core_pattern=$(< /proc/sys/kernel/core_pattern)
 	mkdir -p "$output_dir/coredumps"
-	# set core_pattern to a known value to avoid ABRT, systemd-coredump, etc.
-	echo "|$rootdir/scripts/core-collector.sh %P %s %t %c $output_dir/coredumps" > /proc/sys/kernel/core_pattern
+	# Set core_pattern to a known value to avoid ABRT, systemd-coredump, etc.
+	# Dump the $output_dir path to a file so collector can pick it up while executing.
+	# We don't set in in the core_pattern command line because of the string length limitation
+	# of 128 bytes. See 'man core 5' for details.
+	echo "|$rootdir/scripts/core-collector.sh %P %s %t %c" > /proc/sys/kernel/core_pattern
+	echo "$output_dir/coredumps" > "$rootdir/.coredump_path"
 
 	# make sure nbd (network block device) driver is loaded if it is available
 	# this ensures that when tests need to use nbd, it will be fully initialized

scripts/core-collector.sh

@@ -31,7 +31,6 @@ args+=(core_pid)
 args+=(core_sig)
 args+=(core_ts)
 args+=(rlimit)
-args+=(output_dir)
 
 read -r "${args[@]}" <<< "$*"
 
@@ -41,7 +40,7 @@ statm=$(< "/proc/$core_pid/statm")
 core_time=$(date -d@"$core_ts")
 core_sig_name=$(kill -l "$core_sig")
 
-core=$output_dir/${exe_path##*/}_$core_pid.core
+core=$(< "${0%/*}/../.coredump_path")/${exe_path##*/}_$core_pid.core
 stderr
 
 # RLIMIT_CORE is not enforced when core is piped to us. To make