diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index b7adbd31d6b2688490cbcdc597fe663d5955f7da..2d1cdb3917184c7ae713849af6b1343239595f1f 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -208,7 +208,7 @@ extern struct trace_event_functions exit_syscall_print_funcs;
static inline long SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__))
-asmlinkage long sys_pb_set_plan(struct pb_plan __user *plan);
+asmlinkage long sys_pb_set_plan(pid_t reference_proc_pid);
asmlinkage long sys_pbm_set_root_proc(void);
asmlinkage long sys32_quotactl(unsigned int cmd, const char __user *special,
qid_t id, void __user *addr);
diff --git a/kernel/sched/pb.c b/kernel/sched/pb.c
index 06059907d6075a308f8e3e6bec5ed3ea9e09ca54..f01375d73a0bd6e0375548e31a2ec1ce353ce974 100644
--- a/kernel/sched/pb.c
+++ b/kernel/sched/pb.c
@@ -9,8 +9,7 @@
typedef struct pb_plan pb_plan_t;
-SYSCALL_DEFINE1(pb_set_plan, pb_plan_t __user*, plan) {
- pb_plan_t _plan;
+SYSCALL_DEFINE1(pb_set_plan, pid_t, reference_proc_pid) {
struct task_struct* task;
struct rq* rq;
struct pb_rq* pb_rq;
diff --git a/pb_utils/pb_submitter/pb_submitter.c b/pb_utils/pb_submitter/pb_submitter.c
index 04856044452683865a931a55cdb017b476987f20..296c8d011ae287bb91973b2fca0644abc9270fa5 100644
--- a/pb_utils/pb_submitter/pb_submitter.c
+++ b/pb_utils/pb_submitter/pb_submitter.c
@@ -3,126 +3,116 @@
#include <unistd.h>
#include <stdint.h>
#include <stdlib.h>
+#include <signal.h>
+#include <errno.h> // errno
#define PB_SET_PLAN 0x1337
+// FIXME DRY with the same struct in sched.h
typedef struct {
pid_t pid;
uint64_t *inst_cnt;
size_t num_tasks;
+ pid_t ref_pid;
} pb_plan_t;
static void usage(void)
{
- puts("Usage: ./pb_submitter <prog_name> <plan_file>");
+ puts("Usage: echo '<ref_proc_pid>' | ./pb_submitter <prog_name> <prog_arg_0> ...");
}
-static size_t count_lines(FILE *fp)
+volatile sig_atomic_t stop;
+
+static void handler(int n)
{
- char c;
- size_t lines = 0;
- while (!feof(fp)) {
- c = fgetc(fp);
- if (c == '\n') {
- lines++;
- }
- }
+ stop = 1;
+}
- rewind(fp);
+volatile sig_atomic_t stop;
- return lines;
+static void handler(int n)
+{
+ stop = 1;
}
int main(int argc, char** argv)
{
- if (argc < 0x3) {
- usage();
- return -1;
- }
-
int ret;
- pb_plan_t plan = { 0 };
- FILE *fp;
- char *line = NULL;
- size_t len = 0;
- ssize_t cnt;
- int pipes[0x2];
-
- ret = pipe(pipes);
- if (ret < 0) {
- perror("pipe");
- return -1;
- }
+ pid_t ref_proc;
+ errno = 0;
- fp = fopen(argv[2], "r");
- if (fp == NULL) {
+ char buf[12]; // large enough buffer for even the largest pid
+ scanf("%11s", buf); // read what we have in stdin and drop the ending null
+ if (sscanf(buf, "%u", &ref_proc) != 1) {
+ printf("Error: Invalid stdin input (pid expected): %s; Errno: \n", strerror(errno));
usage();
return -1;
}
+ printf("Got: %u\n", ref_proc);
- plan.num_tasks = count_lines(fp);
-
- uint64_t* inst_cnt = calloc(plan.num_tasks, sizeof(uint64_t));
- if (inst_cnt == NULL) {
- perror("calloc");
+ // TODO Add the reference proc pid as argument (arc < 3)?
+ if (argc < 2) {
+ usage();
return -1;
}
- size_t i;
- for (i = 0; i < plan.num_tasks; i++) {
- cnt = getline(&line, &len, fp);
-
- if (cnt < 0) {
- perror("getline");
- return -1;
- }
-
- uint64_t cnt = strtoull(line, NULL, 10);
-
- if (inst_cnt == 0) {
- puts("Inst_cnt conversion failure");
- return -1;
- }
-
- inst_cnt[i] = cnt;
- }
-
- plan.inst_cnt = inst_cnt;
-
pid_t pid = fork();
if (pid == 0x0) {
- char *const args[] = {argv[1], NULL};
- char *const env[] = {NULL};
-
- write(pipes[0x1], "a", sizeof("a"));
-
- ret = execve(argv[1], args, env);
+ // drop the first element of argv (the name of this program) so that only
+ // the name and arguments of the program to run remain
+ char ** args = &argv[1];
+
+ puts(" ###### STOP");
+ kill(getpid(), SIGTSTP);
+ puts(" ###### CONTINUE");
+
+ // replace this process with the chosen program since we want to keep using
+ // the same PID for simplicity purposes (forking a new process would have
+ // worked as well but this process is not needed anymore anyways)
+ ret = execvp(argv[1], args);
if (ret < 0) {
perror("execve");
return -1;
}
- }
- else {
+ } else {
/**
* Wait for execve of child to finish else pb cycles are wasted inside
* the execve function.
*
- * todo: find better method to do this
+ * Setup a signal handler for the SIGCHLD-Signal that the parent receives when the child is
+ * stopped (by SIGTSTP)
+ *
+ * idea for the signal handler:
+ * https://stackoverflow.com/questions/40098170/handling-sigtstp-signals-in-c/40116030#40116030
+ * idea for using it in combination with pause() instead of wait:
+ * https://stackoverflow.com/questions/12683466/after-suspending-child-process-with-sigtstp-shell-not-responding/43614414#43614414
*/
- sleep(0x1);
- char c;
- read(pipes[0x0], &c, sizeof(char));
+ struct sigaction sa;
+ sa.sa_handler = handler;
+ sa.sa_flags = 0;
+ sigemptyset(&sa.sa_mask);
+ if (sigaction(SIGCHLD, &sa, NULL) == -1) {
+ perror("Couldn't set SIGCHLD handler");
+ exit(EXIT_FAILURE);
+ }
+ // wait for the child to signal the stop
+ pause();
- plan.pid = pid;
+ printf("Selected plan (reference pid): %u, real pid: %u\n", ref_proc, pid);
+ ret = syscall(PB_SET_PLAN, ref_proc);
- ret = syscall(PB_SET_PLAN, &plan);
+ // continue running the child
+ kill(pid, SIGCONT);
if (ret < 0) {
puts("PB_SET_PLAN failed");
return -1;
}
+
+ // continue running the child
+ kill(pid, SIGCONT);
}
return 0;