[PATCH v1 09/12] netoops: Add an interface to trigger various types of crashes.

Mike Waychison
2010-11-03T01:30:41Z

It is very useful to be able to test the crash path, but in order to do so, we
need to expose various ways to crash the kernel in a deterministic fashion.

This commit adds a file, /proc/sys/kernel/net_dump_now that takes various
tokens that will crash the kernel in various ways.

Signed-off-by: Mike Waychison <mikew@google.com>
---

This trigger is probably better done using an ABI that is much more generic.
It could perhaps be an extension of /proc/sysrq-trigger, though it would be
nice to have the 'types' of crashes enumerated in a programmable manner somehow
to know if they are available or not.
---
drivers/net/netoops.c | 31 +++++++++++++++++++++++++++++++
1 files changed, 31 insertions(+), 0 deletions(-)

diff --git a/drivers/net/netoops.c b/drivers/net/netoops.c
index 01432d7..87b2122 100644
--- a/drivers/net/netoops.c
+++ b/drivers/net/netoops.c
@@ -578,6 +578,32 @@ static int proc_netoops_device(struct ctl_table *table, int write,
return 0;
}

+static int proc_netoops_now(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ if (write) {
+ char magic[20];
+ /* just crash in kernel mode. */
+ if (copy_from_user(magic, buffer, min(*lenp, sizeof(magic))))
+ return -EFAULT;
+ magic[min(*lenp, sizeof(magic))-1] = 0;
+ if (!strcmp(magic, "elgooG")) {
+ /* Test a simple crash */
+ *(unsigned long *)0 = 0;
+ } else if (!strcmp(magic, "guB")) {
+ /* Test the BUG() handler */
+ BUG();
+ } else if (!strcmp(magic, "cinaP")) {
+ panic("Testing panic");
+ } else if (!strcmp(magic, "pmuD")) {
+ kmsg_dump(KMSG_DUMP_SOFT, NULL);
+ }
+ return 0;
+ }
+ *lenp = 0;
+ return 0;
+}
+
static struct ctl_table kern_table[] = {
{
.procname = "net_dump_device",
@@ -585,6 +611,11 @@ static struct ctl_table kern_table[] = {
.proc_handler = &proc_netoops_device,
},
{
+ .procname = "net_dump_now",
+ .mode = 0600,
+ .proc_handler = &proc_netoops_now,
+ },
+ {
.procname = "net_dump_one_shot",
.data = &network_dumper_one_shot,
.maxlen = sizeof(int),