procfs: add support for <pid>/mem files and ad hoc fix for memory incoherency.

executer/kernel/mcctrl.h

@@ -164,6 +164,7 @@ struct procfs_read {
 	unsigned long pbuf;	/* physical address of the host buffer (request) */
 	unsigned long offset;	/* offset to read (request) */
 	int count;		/* bytes to read (request) */
+	int error;		/* non-zero if below fields are invalid. (answer) */
 	int eof;		/* if eof is detected, 1 otherwise 0. (answer)*/
 	int ret;		/* read bytes (answer) */
 	int newcpu;		/* migrated new cpu (answer) */

executer/kernel/procfs.c

@@ -254,8 +254,11 @@ void procfs_delete(void *__os, int osnum, unsigned long arg)
 
 void procfs_answer(unsigned int arg, int err)
 {
+	volatile struct procfs_read *r = phys_to_virt(arg);
+
 	dprintk("procfs: received SCD_MSG_PROCFS_ANSWER message(err = %d).\n", err);
 	procfsq_channel = arg;
+	r->error = err;
 	wake_up_interruptible(&procfsq);
 }
 
@@ -274,6 +277,7 @@ int mckernel_procfs_read(char *buffer, char **start, off_t offset,
 	struct ikc_scd_packet isp;
 	int ret, retrycount = 0;
 	unsigned long pbuf;
+	int i;
 
 	dprintk("mckernel_procfs_read: invoked for %s\n", e->fname); 
 
@@ -295,7 +299,7 @@ retry:
 
 	r->pbuf = pbuf;
 	r->eof = 0;
-	r->ret = -EIO;	/* default to error */
+	r->ret = PAGE_SIZE * 2;	/* dummy answer  */
 	r->offset = offset;
 	r->count = count;
 	strncpy((char *)r->fname, e->fname, PROCFS_NAME_MAX);
@@ -310,7 +314,19 @@ retry:
 	dprintk("now wait for a relpy\n");
 	wait_event_interruptible(procfsq, procfsq_channel == virt_to_phys(r));
 	/* Wake up and check the result. */
-	dprintk("mckernel_procfs_read: woke up. ret: %d, eof: %d\n", r->ret, r->eof);
+	dprintk("mckernel_procfs_read: woke up.\n");
+	if (r->error != 0) {
+		kprintf("ERROR: mckernel_procfs_read: failed to get valid answer.\n");
+		return -EIO;
+	}		
+	for (i = 0; r->ret == PAGE_SIZE * 2; i++) {
+		/* FIXME: busy wait for the real answer to reach*/;
+		if (i > 1000000) {
+			kprintf("ERROR: mckernel_procfs_read: answer unavailable.\n");
+			return -EIO;
+		}
+	}
+	dprintk("ret: %d, eof: %d (wait loop count: %d)\n", r->ret, r->eof, i);
 	if ((r->ret == 0) && (r->eof != 1)) {
 		/* A miss-hit caused by migration has occurred.
 		 * We simply retry the query with a new CPU.
@@ -324,6 +340,7 @@ retry:
 		goto retry;
 	}
 	if (r->eof == 1) {
+		dprintk("reached end of file.\n");
 		*peof = 1;
 	}
 	*start = buffer;

kernel/include/syscall.h

@@ -251,6 +251,7 @@ struct procfs_read {
 	unsigned long pbuf;	/* physical address of the host buffer (request) */
 	unsigned long offset;	/* offset to read (request) */
 	int count;		/* bytes to read (request) */
+	int error;		/* non-zero if below fields are invalid. (answer) */
 	int eof;		/* if eof is detected, 1 otherwise 0. (answer)*/
 	int ret;		/* read bytes (answer) */
 	int newcpu;		/* migrated new cpu (answer) */

kernel/procfs.c

@@ -63,6 +63,9 @@ void create_proc_procfs_files(int pid, int cpuid)
 	snprintf(fname, PROCFS_NAME_MAX, "mcos%d/%d/auxv", osnum, pid);
 	create_proc_procfs_file(pid, fname, 0400, cpuid);
 
+	snprintf(fname, PROCFS_NAME_MAX, "mcos%d/%d/mem", osnum, pid);
+	create_proc_procfs_file(pid, fname, 0400, cpuid);
+
 	snprintf(fname, PROCFS_NAME_MAX, "mcos%d/%d/task/%d/mem", osnum, pid, pid);
 	create_proc_procfs_file(pid, fname, 0400, cpuid);
 
@@ -97,7 +100,7 @@ void delete_proc_procfs_files(int pid)
 {
 	char fname[PROCFS_NAME_MAX];
 
-	dprintf("delete procfs files\n");
+	dprintf("delete procfs files for pid %d.\n", pid);
 	snprintf(fname, PROCFS_NAME_MAX, "mcos%d/%d/task/%d/mem", osnum, pid, pid);
 	delete_proc_procfs_file(pid, fname);
 
@@ -110,18 +113,16 @@ void delete_proc_procfs_files(int pid)
 	snprintf(fname, PROCFS_NAME_MAX, "mcos%d/%d/task", osnum, pid);
 	delete_proc_procfs_file(pid, fname);
 
+	snprintf(fname, PROCFS_NAME_MAX, "mcos%d/%d/mem", osnum, pid);
+	delete_proc_procfs_file(pid, fname);
+
 	snprintf(fname, PROCFS_NAME_MAX, "mcos%d/%d/auxv", osnum, pid);
 	delete_proc_procfs_file(pid, fname);
 
 	snprintf(fname, PROCFS_NAME_MAX, "mcos%d/%d", osnum, pid);
 	delete_proc_procfs_file(pid, fname);
 
-	/* CAVEAT: deleting mcos%d level procfs directory should be located 
+	dprintf("delete procfs files for pid %d: done\n", pid);
-	   in delete_mckernel_procfs_files().*/
-	snprintf(fname, PROCFS_NAME_MAX, "mcos%d", osnum);
-	delete_proc_procfs_file(pid, fname);
-
-	dprintf("delete procfs files: done\n");
 }
 
 /**
@@ -286,6 +287,32 @@ void process_procfs_request(unsigned long rarg)
 	dprintf("matched PID: %d.\n", pid);
 	p = strchr(p, '/') + 1;
 
+	/* 
+	 * mcos%d/PID/mem
+	 *
+	 * The offset is treated as the beginning of the virtual address area
+	 * of the process. The count is the length of the area.
+	 */
+	if (strcmp(p, "mem") == 0) {
+		struct vm_range *range;
+		struct process_vm *vm = proc->vm;
+
+		list_for_each_entry(range, &vm->vm_range_list, list) {
+			dprintf("range: %lx - %lx\n", range->start, range->end);
+			if ((range->start <= r->offset) && 
+			    (r->offset < range->end)) {
+				unsigned int len = r->count;
+				if (range->end < r->offset + r->count) {
+					len = range->end - r->offset;
+				}
+				memcpy((void *)buf, (void *)range->start, len);
+				ans = len;
+				break;
+			}
+		}
+		goto end;
+	}
+
 	/* 
 	 * mcos%d/PID/auxv
 	 */
@@ -301,6 +328,9 @@ void process_procfs_request(unsigned long rarg)
 			if (r->offset + len == limit) {
 				eof = 1;
 			}
+		} else if (r->offset == limit) {
+			ans = 0;
+			eof = 1;
 		}
 		goto end;
 	}
@@ -342,6 +372,9 @@ void process_procfs_request(unsigned long rarg)
 		}
 
 		if (!strcmp(p, "stat")) {
+			char tmp[1024];
+			int len;
+
 			if ((proc = findthread_and_lock(pid, tid, &savelock, &irqstate))){
 				dprintf("thread found! pid=%d tid=%d\n", pid, tid);
 				/*
@@ -357,7 +390,7 @@ void process_procfs_request(unsigned long rarg)
 				 * cnswap exit_signal processor rt_priority
 				 * policy delayacct_blkio_ticks guest_time cguest_time
 				 */
-				ans = sprintf((char *)buf,
+				ans = sprintf(tmp,
 				    "%d (%s) %c %d "	      // pid...
 				    "%d %d %d %d "	      // pgrp...
 				    "%u %lu %lu %lu "	      // flags...
@@ -368,7 +401,7 @@ void process_procfs_request(unsigned long rarg)
 				    "%lu %lu %lu %lu "	      // kstkesp...
 				    "%lu %lu %lu %lu "	      // sigignore...
 				    "%lu %d %d %u "	      // cnswap...
-				    "%u %llu %lu %ld",	      // policy...
+				    "%u %llu %lu %ld\n",      // policy...
 				    0, "exe", 'R', 0,	      // pid...
 				    0, 0, 0, 0,      	      // pgrp...
 				    0, 0L, 0L, 0L,	      // flags...
@@ -381,11 +414,22 @@ void process_procfs_request(unsigned long rarg)
 				    0L, 0, proc->cpu_id, 0,   // cnswap...
 				    0, 0LL, 0L, 0L	      // policy...
 				);
-				/* The target process has gone by migration. */
-				r->newcpu = proc->cpu_id;
 				process_unlock(savelock, irqstate);
-				eof = 1;
+				dprintf("tmp=%s\n", tmp);
-				dprintf("buf=%s\n", buf);
+
+				len = strlen(tmp);
+				if (r->offset < len) {
+					if (r->offset + r->count < len) {
+						ans = r->count;
+					} else {
+						eof = 1;
+						ans = len;
+					}
+					strncpy(buf, tmp + r->offset, ans);
+				} else if (r->offset == len) {
+					ans = 0;
+					eof = 1;
+				}
 				goto end;
 			}
 			else{