Commit c4e00daaa96d3a0786f1f4fe6456281c60ef9a16
Committed by
Greg Kroah-Hartman
Greg Kroah-Hartman
1 parent
e11fea92e1
Exists in
smarc-l5.0.0_1.0.0-ga
and in
5 other branches
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 <william.douglas@intel.com>
Signed-off-by: Kay Sievers <kay@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Showing 1 changed file with 49 additions and 3 deletions Side-by-side Diff
drivers/base/core.c
| ... | ... | @@ -25,6 +25,7 @@ |
| 25 | 25 | #include <linux/mutex.h> |
| 26 | 26 | #include <linux/async.h> |
| 27 | 27 | #include <linux/pm_runtime.h> |
| 28 | +#include <linux/netdevice.h> | |
| 28 | 29 | |
| 29 | 30 | #include "base.h" |
| 30 | 31 | #include "power/power.h" |
| 31 | 32 | |
| 32 | 33 | |
| ... | ... | @@ -1843,15 +1844,60 @@ |
| 1843 | 1844 | */ |
| 1844 | 1845 | |
| 1845 | 1846 | #ifdef CONFIG_PRINTK |
| 1846 | - | |
| 1847 | 1847 | int __dev_printk(const char *level, const struct device *dev, |
| 1848 | 1848 | struct va_format *vaf) |
| 1849 | 1849 | { |
| 1850 | + char dict[128]; | |
| 1851 | + size_t dictlen = 0; | |
| 1852 | + const char *subsys; | |
| 1853 | + | |
| 1850 | 1854 | if (!dev) |
| 1851 | 1855 | return printk("%s(NULL device *): %pV", level, vaf); |
| 1852 | 1856 | |
| 1853 | - return printk("%s%s %s: %pV", | |
| 1854 | - level, dev_driver_string(dev), dev_name(dev), vaf); | |
| 1857 | + if (dev->class) | |
| 1858 | + subsys = dev->class->name; | |
| 1859 | + else if (dev->bus) | |
| 1860 | + subsys = dev->bus->name; | |
| 1861 | + else | |
| 1862 | + goto skip; | |
| 1863 | + | |
| 1864 | + dictlen += snprintf(dict + dictlen, sizeof(dict) - dictlen, | |
| 1865 | + "SUBSYSTEM=%s", subsys); | |
| 1866 | + | |
| 1867 | + /* | |
| 1868 | + * Add device identifier DEVICE=: | |
| 1869 | + * b12:8 block dev_t | |
| 1870 | + * c127:3 char dev_t | |
| 1871 | + * n8 netdev ifindex | |
| 1872 | + * +sound:card0 subsystem:devname | |
| 1873 | + */ | |
| 1874 | + if (MAJOR(dev->devt)) { | |
| 1875 | + char c; | |
| 1876 | + | |
| 1877 | + if (strcmp(subsys, "block") == 0) | |
| 1878 | + c = 'b'; | |
| 1879 | + else | |
| 1880 | + c = 'c'; | |
| 1881 | + dictlen++; | |
| 1882 | + dictlen += snprintf(dict + dictlen, sizeof(dict) - dictlen, | |
| 1883 | + "DEVICE=%c%u:%u", | |
| 1884 | + c, MAJOR(dev->devt), MINOR(dev->devt)); | |
| 1885 | + } else if (strcmp(subsys, "net") == 0) { | |
| 1886 | + struct net_device *net = to_net_dev(dev); | |
| 1887 | + | |
| 1888 | + dictlen++; | |
| 1889 | + dictlen += snprintf(dict + dictlen, sizeof(dict) - dictlen, | |
| 1890 | + "DEVICE=n%u", net->ifindex); | |
| 1891 | + } else { | |
| 1892 | + dictlen++; | |
| 1893 | + dictlen += snprintf(dict + dictlen, sizeof(dict) - dictlen, | |
| 1894 | + "DEVICE=+%s:%s", subsys, dev_name(dev)); | |
| 1895 | + } | |
| 1896 | +skip: | |
| 1897 | + return printk_emit(0, level[1] - '0', | |
| 1898 | + dictlen ? dict : NULL, dictlen, | |
| 1899 | + "%s %s: %pV", | |
| 1900 | + dev_driver_string(dev), dev_name(dev), vaf); | |
| 1855 | 1901 | } |
| 1856 | 1902 | EXPORT_SYMBOL(__dev_printk); |
| 1857 | 1903 |