Add support for letting userland define a 32bit boot id. This is useful for users to be able to correlate netoops reports to specific boot instances offline.
Signed-off-by: Mike Waychison <[email protected]> --- Changelog: - v3 - boot_id is always little-endian on the network. - This patch adds a dependency on sysfs. Declare the dependency in the Kconfig. --- drivers/net/Kconfig | 1 + drivers/net/netoops.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 64 insertions(+), 1 deletions(-) diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig index 0e9fae3..0098124 100644 --- a/drivers/net/Kconfig +++ b/drivers/net/Kconfig @@ -3396,6 +3396,7 @@ config NETCONSOLE_DYNAMIC config NETOOPS tristate "Network oops support" + depends on SYSFS select NETPOLL_TARGETS select NETPOLL_TARGETS_DYNAMIC help diff --git a/drivers/net/netoops.c b/drivers/net/netoops.c index f7665ad..6c4c0f2 100644 --- a/drivers/net/netoops.c +++ b/drivers/net/netoops.c @@ -91,6 +91,7 @@ struct netoops_msg { __le16 type; __le32 packet_count; __le32 packet_no; + __le32 boot_id; /* * NOTE: fixed length strings for a packet. NULL * termination not required. @@ -103,6 +104,8 @@ struct netoops_msg { static struct netoops_msg msg; +static u32 netoops_boot_id; + static void setup_packet_header(int packet_count, struct pt_regs *regs, int soft_dump) { @@ -116,6 +119,7 @@ static void setup_packet_header(int packet_count, struct pt_regs *regs, h->type = cpu_to_le16(soft_dump ? NETOOPS_TYPE_PRINTK_BUFFER_SOFT : NETOOPS_TYPE_PRINTK_BUFFER); h->packet_count = cpu_to_le32(packet_count); + h->boot_id = cpu_to_le32(netoops_boot_id); strncpy(h->kernel_version, utsname()->release, min(sizeof(msg.header.kernel_version), sizeof(utsname()->release))); @@ -217,6 +221,49 @@ static void netoops(struct kmsg_dumper *dumper, enum kmsg_dump_reason reason, spin_unlock_irqrestore(&targets.lock, flags); } +static ssize_t netoops_show(struct kobject *kobj, + struct kobj_attribute *attr, + char *buf) { + if (!strcmp(attr->attr.name, "netoops_boot_id")) + snprintf(buf, PAGE_SIZE, "%d\n", netoops_boot_id); + buf[PAGE_SIZE - 1] = '\0'; + return strnlen(buf, PAGE_SIZE); +} + +static ssize_t netoops_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, + size_t count) { + if (!count) + return count; + + if (!strcmp(attr->attr.name, "netoops_boot_id")) { + unsigned long tmp; + if (strict_strtoul(buf, 0, &tmp)) + return -EINVAL; + if (tmp > UINT_MAX) + printk("Warning: truncating boot_id to 32bits."); + netoops_boot_id = tmp; + } else + return -EINVAL; + + return count; +} + +static struct kobj_attribute netoops_boot_number_attribute = + __ATTR(netoops_boot_id, 0666, netoops_show, netoops_store); + +static struct attribute *attrs[] = { + &netoops_boot_number_attribute.attr, + NULL, +}; + +static struct attribute_group attr_group = { + .attrs = attrs, +}; + +static struct kobject *netoops_kobj; + static struct kmsg_dumper netoops_dumper = { .dump = netoops, }; @@ -233,6 +280,7 @@ static int __init netoops_init(void) BUILD_BUG_ON(offsetof(struct netoops_msg, header.type) != 10); BUILD_BUG_ON(offsetof(struct netoops_msg, header.packet_count) != 12); BUILD_BUG_ON(offsetof(struct netoops_msg, header.packet_no) != 16); + BUILD_BUG_ON(offsetof(struct netoops_msg, header.boot_id) != 20); targets.default_local_port = NETOOPS_PORT; targets.default_remote_port = NETOOPS_PORT; @@ -242,11 +290,23 @@ static int __init netoops_init(void) if (retval) goto out; + netoops_kobj = kobject_create_and_add("netoops", kernel_kobj); + if (!netoops_kobj) + goto out_targets; + + retval = sysfs_create_group(netoops_kobj, &attr_group); + if (retval) + goto out_kobj; + retval = kmsg_dump_register(&netoops_dumper); if (retval) - goto out_targets; + goto out_sysfs_group; return 0; +out_sysfs_group: + sysfs_remove_group(netoops_kobj, &attr_group); +out_kobj: + kobject_put(netoops_kobj); out_targets: unregister_netpoll_targets(&targets); out: @@ -256,6 +316,8 @@ out: static void __exit netoops_exit(void) { kmsg_dump_unregister(&netoops_dumper); + sysfs_remove_group(netoops_kobj, &attr_group); + kobject_put(netoops_kobj); unregister_netpoll_targets(&targets); } -- 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
