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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/samples/kprobes/jprobe_example.c
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/samples/kprobes/jprobe_example.c')
-rw-r--r--kernel/samples/kprobes/jprobe_example.c67
1 files changed, 67 insertions, 0 deletions
diff --git a/kernel/samples/kprobes/jprobe_example.c b/kernel/samples/kprobes/jprobe_example.c
new file mode 100644
index 000000000..9119ac6a8
--- /dev/null
+++ b/kernel/samples/kprobes/jprobe_example.c
@@ -0,0 +1,67 @@
+/*
+ * Here's a sample kernel module showing the use of jprobes to dump
+ * the arguments of do_fork().
+ *
+ * For more information on theory of operation of jprobes, see
+ * Documentation/kprobes.txt
+ *
+ * Build and insert the kernel module as done in the kprobe example.
+ * You will see the trace data in /var/log/messages and on the
+ * console whenever do_fork() is invoked to create a new process.
+ * (Some messages may be suppressed if syslogd is configured to
+ * eliminate duplicate messages.)
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/kprobes.h>
+
+/*
+ * Jumper probe for do_fork.
+ * Mirror principle enables access to arguments of the probed routine
+ * from the probe handler.
+ */
+
+/* Proxy routine having the same arguments as actual do_fork() routine */
+static long jdo_fork(unsigned long clone_flags, unsigned long stack_start,
+ unsigned long stack_size, int __user *parent_tidptr,
+ int __user *child_tidptr)
+{
+ pr_info("jprobe: clone_flags = 0x%lx, stack_start = 0x%lx "
+ "stack_size = 0x%lx\n", clone_flags, stack_start, stack_size);
+
+ /* Always end with a call to jprobe_return(). */
+ jprobe_return();
+ return 0;
+}
+
+static struct jprobe my_jprobe = {
+ .entry = jdo_fork,
+ .kp = {
+ .symbol_name = "do_fork",
+ },
+};
+
+static int __init jprobe_init(void)
+{
+ int ret;
+
+ ret = register_jprobe(&my_jprobe);
+ if (ret < 0) {
+ printk(KERN_INFO "register_jprobe failed, returned %d\n", ret);
+ return -1;
+ }
+ printk(KERN_INFO "Planted jprobe at %p, handler addr %p\n",
+ my_jprobe.kp.addr, my_jprobe.entry);
+ return 0;
+}
+
+static void __exit jprobe_exit(void)
+{
+ unregister_jprobe(&my_jprobe);
+ printk(KERN_INFO "jprobe at %p unregistered\n", my_jprobe.kp.addr);
+}
+
+module_init(jprobe_init)
+module_exit(jprobe_exit)
+MODULE_LICENSE("GPL");