From c4e00daaa96d3a0786f1f4fe6456281c60ef9a16 Mon Sep 17 00:00:00 2001 From: Kay Sievers Date: Thu, 3 May 2012 02:29:59 +0200 Subject: [PATCH] driver-core: extend dev_printk() to pass structured data Extends dev_printk() to attach a dictionary with a device identifier and the driver core subsystem name to logged messages, which makes dev_prink() reliable machine-readable. In addition to the printed plain text message, it creates these properties: SUBSYSTEM= - the driver-core subsytem name DEVICE= b12:8 - block dev_t c127:3 - char dev_t n8 - netdev ifindex +sound:card0 - subsystem:devname Tested-by: William Douglas Signed-off-by: Kay Sievers Signed-off-by: Greg Kroah-Hartman --- drivers/base/core.c | 52 ++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 49 insertions(+), 3 deletions(-) diff --git a/drivers/base/core.c b/drivers/base/core.c index 33461ec35d8f..346be8b78b24 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -25,6 +25,7 @@ #include #include #include +#include #include "base.h" #include "power/power.h" @@ -1843,15 +1844,60 @@ void device_shutdown(void) */ #ifdef CONFIG_PRINTK - int __dev_printk(const char *level, const struct device *dev, struct va_format *vaf) { + char dict[128]; + size_t dictlen = 0; + const char *subsys; + if (!dev) return printk("%s(NULL device *): %pV", level, vaf); - return printk("%s%s %s: %pV", - level, dev_driver_string(dev), dev_name(dev), vaf); + if (dev->class) + subsys = dev->class->name; + else if (dev->bus) + subsys = dev->bus->name; + else + goto skip; + + dictlen += snprintf(dict + dictlen, sizeof(dict) - dictlen, + "SUBSYSTEM=%s", subsys); + + /* + * Add device identifier DEVICE=: + * b12:8 block dev_t + * c127:3 char dev_t + * n8 netdev ifindex + * +sound:card0 subsystem:devname + */ + if (MAJOR(dev->devt)) { + char c; + + if (strcmp(subsys, "block") == 0) + c = 'b'; + else + c = 'c'; + dictlen++; + dictlen += snprintf(dict + dictlen, sizeof(dict) - dictlen, + "DEVICE=%c%u:%u", + c, MAJOR(dev->devt), MINOR(dev->devt)); + } else if (strcmp(subsys, "net") == 0) { + struct net_device *net = to_net_dev(dev); + + dictlen++; + dictlen += snprintf(dict + dictlen, sizeof(dict) - dictlen, + "DEVICE=n%u", net->ifindex); + } else { + dictlen++; + dictlen += snprintf(dict + dictlen, sizeof(dict) - dictlen, + "DEVICE=+%s:%s", subsys, dev_name(dev)); + } +skip: + return printk_emit(0, level[1] - '0', + dictlen ? dict : NULL, dictlen, + "%s %s: %pV", + dev_driver_string(dev), dev_name(dev), vaf); } EXPORT_SYMBOL(__dev_printk); -- GitLab