svn commit: r256598 - in user/glebius/course/04.synchronisation/code: . application call module

[Gleb Smirnoff]

Author: glebius
Date: Wed Oct 16 08:48:45 2013
New Revision: 256598
URL: http://svnweb.freebsd.org/changeset/base/256598

Log:
  An example module that handles a double linked list in racy manner.

Added:
  user/glebius/course/04.synchronisation/code/
     - copied from r256591, user/glebius/course/02.entering_kernel/syscall/
  user/glebius/course/04.synchronisation/code/call/
     - copied from r256591, user/glebius/course/02.entering_kernel/syscall/application/
  user/glebius/course/04.synchronisation/code/module/api.h   (contents, props changed)
  user/glebius/course/04.synchronisation/code/module/syscall.c
     - copied, changed from r256591, user/glebius/course/02.entering_kernel/syscall/module/foo_syscall.c
Deleted:
  user/glebius/course/04.synchronisation/code/application/
  user/glebius/course/04.synchronisation/code/module/foo_syscall.c
Modified:
  user/glebius/course/04.synchronisation/code/Makefile
  user/glebius/course/04.synchronisation/code/call/Makefile
  user/glebius/course/04.synchronisation/code/call/call.c
  user/glebius/course/04.synchronisation/code/module/Makefile

Modified: user/glebius/course/04.synchronisation/code/Makefile
==============================================================================
--- user/glebius/course/02.entering_kernel/syscall/Makefile	Wed Oct 16 06:15:40 2013	(r256591)
+++ user/glebius/course/04.synchronisation/code/Makefile	Wed Oct 16 08:48:45 2013	(r256598)
@@ -1,3 +1,3 @@
-SUBDIR= module application
+SUBDIR= module call
 
 .include <bsd.subdir.mk>

Modified: user/glebius/course/04.synchronisation/code/call/Makefile
==============================================================================
--- user/glebius/course/02.entering_kernel/syscall/application/Makefile	Wed Oct 16 06:15:40 2013	(r256591)
+++ user/glebius/course/04.synchronisation/code/call/Makefile	Wed Oct 16 08:48:45 2013	(r256598)
@@ -1,4 +1,6 @@
 PROG=	call
+CFLAGS+= -I../module
+
 NO_MAN=
 
 .include <bsd.prog.mk>

Modified: user/glebius/course/04.synchronisation/code/call/call.c
==============================================================================
--- user/glebius/course/02.entering_kernel/syscall/application/call.c	Wed Oct 16 06:15:40 2013	(r256591)
+++ user/glebius/course/04.synchronisation/code/call/call.c	Wed Oct 16 08:48:45 2013	(r256598)
@@ -5,13 +5,17 @@
 #include <err.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <unistd.h>
 
+#include <api.h>
+
 int
 main(int argc, char **argv)
 {
 	int modid, syscall_num;
 	struct module_stat stat;
+	int what;
 
 	stat.version = sizeof(stat);
 	if ((modid = modfind("sys/foo_syscall")) == -1)
@@ -20,5 +24,15 @@ main(int argc, char **argv)
 		err(1, "modstat");
 	syscall_num = stat.data.intval;
 
-	return syscall(syscall_num, argc, argv);
+	if (argc < 2)
+		err(1, "argument required");
+
+	if (strcmp(argv[1], "add") == 0)
+		what = ADD;
+	else if (strcmp(argv[1], "delete") == 0)
+		what = DELETE;
+	else
+		err(1, "add or delete");
+
+	return syscall(syscall_num, what, argv);
 }

Modified: user/glebius/course/04.synchronisation/code/module/Makefile
==============================================================================
--- user/glebius/course/02.entering_kernel/syscall/module/Makefile	Wed Oct 16 06:15:40 2013	(r256591)
+++ user/glebius/course/04.synchronisation/code/module/Makefile	Wed Oct 16 08:48:45 2013	(r256598)
@@ -1,4 +1,4 @@
-KMOD=   foo_syscall
-SRCS=   foo_syscall.c
+KMOD=   syscall
+SRCS=   syscall.c
 
 .include <bsd.kmod.mk>

Added: user/glebius/course/04.synchronisation/code/module/api.h
==============================================================================
--- /dev/null	00:00:00 1970	(empty, because file is newly added)
+++ user/glebius/course/04.synchronisation/code/module/api.h	Wed Oct 16 08:48:45 2013	(r256598)
@@ -0,0 +1,4 @@
+enum {
+	ADD = 1,
+	DELETE
+};

Copied and modified: user/glebius/course/04.synchronisation/code/module/syscall.c (from r256591, user/glebius/course/02.entering_kernel/syscall/module/foo_syscall.c)
==============================================================================
--- user/glebius/course/02.entering_kernel/syscall/module/foo_syscall.c	Wed Oct 16 06:15:40 2013	(r256591, copy source)
+++ user/glebius/course/04.synchronisation/code/module/syscall.c	Wed Oct 16 08:48:45 2013	(r256598)
@@ -6,6 +6,8 @@
 #include <sys/kernel.h>
 #include <sys/systm.h>
 
+#include <api.h>
+
 /*
  * ABI for arguments. Arguments should be aligned by
  * register size.
@@ -24,6 +26,14 @@ struct foo_args {
 	char p_l_[PADL_(int)]; void *p; char p_r_[PADR_(int)];
 };
 
+struct foo_entry {
+	LIST_ENTRY(foo_entry)	foo_link;
+};
+
+static LIST_HEAD(, foo_entry)	foo_head;
+
+MALLOC_DEFINE(M_FOO, "foo", "foo entries");
+
 /*
  * The function implementing the syscall.
  */
@@ -31,9 +41,25 @@ static int
 foo_syscall(struct thread *td, void *arg)
 {
 	struct foo_args *args = (struct foo_args *)arg;
+	struct foo_entry *ent;
+	int d = args->d;
+
+	switch (d) {
+	case ADD:
+		ent = malloc(sizeof(*ent), M_FOO, M_WAITOK);
+		LIST_INSERT_HEAD(&foo_head, ent, foo_link);
+		break;
+	case DELETE:
+		ent = LIST_FIRST(&foo_head);
+		if (ent) {
+			LIST_REMOVE(ent, foo_link);
+			free(ent, M_FOO);
+		}
+		break;
+	default:
+		return (EINVAL);
+	};
 
-	printf("arguments %d %p\n",
-	    args->d, args->p);
 	return (0);
 }
 
@@ -59,6 +85,7 @@ foo_load(struct module *module, int cmd,
 
 	switch (cmd) {
 	case MOD_LOAD :
+		LIST_INIT(&foo_head);
 		printf("syscall loaded at %d\n", offset);
 		break;
 	case MOD_UNLOAD :