@@ -58,6 +58,7 @@ config DYNAMIC_DEBUG
implicitly compiles in all pr_debug() and dev_dbg() calls, which
enlarges the kernel text size by about 2%.
+
If a source file is compiled with DEBUG flag set, any
pr_debug() calls in it are enabled by default, but can be
disabled at runtime as below. Note that DEBUG flag is
@@ -113,6 +114,58 @@ config DYNAMIC_DEBUG
See Documentation/dynamic-debug-howto.txt for additional information.
+choice
+ prompt "Display errors in printk as"
+ default PRINTK_ERROR_CODES_ONLY
+ depends on PRINTK
+ help
+ This option tells printk how to display error codes when
+ formatted with the %de format code (a Linux printk extension).
+ Error codes are most commonly passed to userspace when syscalls
+ return where they are then translated into localized descrptions
+ via libc's strerror(), perror(), etc. However, many error
+ conditions (for drivers and such) are only reported via printks
+ where there is no such userspace mechanism to reliably translate
+ error numbers into something a little more human.
+
+ This option allows you to perform that translation in the kernel,
+ at the cost of a slightly larger kernel. Note that no native
+ language support is currently, or may ever be provided.
+
+ If unsure, choose "Error codes only".
+
+config PRINTK_ERROR_CODES_ONLY
+ bool "Error codes only"
+ help
+ Just display the error number.
+
+config PRINTK_ERROR_NAMES
+ bool "Error names"
+ select STRERROR_NAME
+ help
+ This option causes printk messages containing an error code to
+ print the name of the error in addition to the error number.
+ Enabling this adds about 2k. Example: -22 (EINVAL)
+
+config PRINTK_ERROR_DESCS
+ bool "Full descrptions"
+ select STRERROR
+ select STRERROR_NAME
+ help
+ This option causes printk messages containing an error code to
+ print the description of errors (in addition to the name and
+ number) and can be helpful for those with aversions to search
+ engines. Enabling this adds about 6k over error codes alone.
+ Example: -90 (EMSGSIZE: Message too long)
+
+endchoice
+
+config STRERROR
+ bool
+
+config STRERROR_NAME
+ bool
+
endmenu # "printk and dmesg options"
menu "Compile-time checks and compiler options"
This adds to lib/Kconfig.debug the options for printk messages to display either error number only (the current behavior), number and error name or number, name and description. These options in turn select STRERROR_NAME and STRERROR as needed, so I'm not adding any direct options to enable those, although it can be added later if somebody needs strerror() or strerror_name() when not enabled in printks. kconfg Signed-off-by: Daniel Santos <daniel.santos@pobox.com> --- lib/Kconfig.debug | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+)