Embed commands to invoke into init.c via mkinitrd.sh args. This allows init to spawn a child process running the command with the required arguments.
Signed-off-by: Joel Fernandes (Google) joel@joelfernandes.org --- .../selftests/rcutorture/bin/mkinitrd.sh | 35 +++++++++++++++++-- 1 file changed, 33 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/rcutorture/bin/mkinitrd.sh b/tools/testing/selftests/rcutorture/bin/mkinitrd.sh index f3f867129560..4ba5e962e3cf 100755 --- a/tools/testing/selftests/rcutorture/bin/mkinitrd.sh +++ b/tools/testing/selftests/rcutorture/bin/mkinitrd.sh @@ -2,6 +2,9 @@ # SPDX-License-Identifier: GPL-2.0+ # # Create an initrd directory if one does not already exist. +# Usage: mkinitrd.sh [command [args...]] +# Example: mkinitrd.sh stress-ng --cpu 1 --cpu-method matrixprod --cpu-ops 1000000 --perf -t 5 +# Note that command/args are optional. # # Copyright (C) IBM Corporation, 2013 # @@ -25,7 +28,9 @@ echo "Creating a statically linked C-language initrd" cd $D mkdir -p initrd cd initrd -cat > init.c << '___EOF___' + +# Generate the init.c with optional command +cat > init.c << 'EOF_HEAD' #ifndef NOLIBC #include <unistd.h> #include <sys/time.h> @@ -33,6 +38,29 @@ cat > init.c << '___EOF___'
volatile unsigned long delaycount;
+void run_optional_command() { +EOF_HEAD + +if [ $# -gt 0 ]; then + # If command provided, generate run_optional_command() with the specified command. + # We use printf to generate the command and args. + # Example: echo $(printf '"%s", ' cmd a1 a2) gives: "cmd", "a1", "a2", + cat >> init.c << EOF + pid_t pid = fork(); + if (pid == 0) { + char *args[] = {$(printf '"%s", ' "$@")NULL}; + execve(args[0], args, NULL); + } +EOF +else + # If no command provided, function will be empty + echo " /* No command specified */" >> init.c +fi + +# Add the rest of the program +cat >> init.c << 'EOF_TAIL' +} + int main(int argc, char *argv[]) { int i; @@ -43,6 +71,9 @@ int main(int argc, char *argv[]) for (i = 0; i < argc; i++) printf(" %s", argv[i]); printf("\n"); + + run_optional_command(); + for (;;) { sleep(1); /* Need some userspace time. */ @@ -62,7 +93,7 @@ int main(int argc, char *argv[]) } return 0; } -___EOF___ +EOF_TAIL
# build using nolibc on supported archs (smaller executable) and fall # back to regular glibc on other ones.