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. This requires kmsg_dump() be accessible to modules, so export it. Signed-off-by: Mike Waychison <[email protected]> --- Changelog: - v2 - Folded EXPORT_SYMBOL_GPL(kmsg_dump) into this patch TODO: User visible ABI needs a better interface --- drivers/net/netoops.c | 31 +++++++++++++++++++++++++++++++ kernel/printk.c | 1 + 2 files changed, 32 insertions(+), 0 deletions(-) diff --git a/drivers/net/netoops.c b/drivers/net/netoops.c index 1ffd0f0..60683c5 100644 --- a/drivers/net/netoops.c +++ b/drivers/net/netoops.c @@ -288,6 +288,32 @@ static struct kmsg_dumper netoops_dumper = { .dump = netoops, }; +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_one_shot", @@ -296,6 +322,11 @@ static struct ctl_table kern_table[] = { .mode = 0644, .proc_handler = &proc_dointvec, }, + { + .procname = "net_dump_now", + .mode = 0600, + .proc_handler = &proc_netoops_now, + }, {}, }; diff --git a/kernel/printk.c b/kernel/printk.c index 159b4d6..9323339 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -1573,4 +1573,5 @@ void kmsg_dump(enum kmsg_dump_reason reason, struct pt_regs *pt_regs) dumper->dump(dumper, reason, pt_regs, s1, l1, s2, l2); spin_unlock_irqrestore(&dump_list_lock, flags); } +EXPORT_SYMBOL_GPL(kmsg_dump); #endif -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
