Introduce print_hex_dump_debug() that can be dynamically controlled, similar to
pr_debug.
Also, make print_hex_dump_bytes() dynamically controlled
Implement only 'p' flag (_DPRINTK_FLAGS_PRINT) to keep it simple since hex dump prints
multiple lines and long prefix would impact readability.
To provide line/file etc. information, use pr_debug or similar
before/after print_hex_dump_debug()
Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In dynamic-debug-howto.txt:
- add section: Debug Messages at Module Initialization Time
- update flags indicators in example outputs to include '='
- make flags descriptions tabular
- add item on '_' flag-char
- add dyndbg, boot-args examples
- rewrap some paragraphs with long lines
In Kconfig.debug, note that compiling with -DDEBUG enables all
pr_debug()s in that code.
In kernel-parameters.txt, add dyndbg and module.dyndbg items,
and deprecate ddebug_query.
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Acked-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Insert ddebug_exec_queries() in place of ddebug_exec_query(). It
splits the query string on [;\n], and calls ddebug_exec_query() on
each. All queries are processed independent of errors, allowing a
query to fail, for example when a module is not installed. Empty
lines and comments are skipped. Errors are counted, and the last
error seen (negative) or the number of callsites found (0 or positive)
is returned. Return code checks are altered accordingly.
With this, multiple queries can be given in ddebug_query, allowing
more selective enabling of callsites. As a side effect, a set of
commands can be batched in:
cat cmd-file > $DBGMT/dynamic_debug/control
We dont want a ddebug_query syntax error to kill the dynamic debug
facility, so dynamic_debug_init() zeros ddebug_exec_queries()'s return
code after logging the appropriate message, so that ddebug tables are
preserved and $DBGMT/dynamic_debug/control file is created. This
would be appropriate even without accepting multiple queries.
This patch also alters ddebug_change() to return number of callsites
matched (which typically is the same as number of callsites changed).
ddebug_exec_query() also returns the number found, or a negative value
if theres a parse error on the query.
Splitting on [;\n] prevents their use in format-specs, but selecting
callsites on punctuation is brittle anyway, meaningful and selective
substrings are more typical.
Note: splitting queries on ';' before handling trailing #comments
means that a ';' also terminates a comment, and text after the ';' is
treated as another query. This trailing query will almost certainly
result in a parse error and thus have no effect other than the error
message. The double corner case with unexpected results is:
ddebug_query="func foo +p # enable foo ; +p"
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
trim_prefix(path) skips past the absolute source path root, and
returns the pointer to the relative path from there. It is used to
shorten the displayed path in $DBGMT/dynamic_debug/control via
ddebug_proc_show(), and in ddebug_change() to allow relative filenames
to be used in applied queries. For example:
~# echo file kernel/freezer.c +p > $DBGMT/dynamic_debug/control
kernel/freezer.c:128 [freezer]cancel_freezing p " clean up: %s\012"
trim_prefix(path) insures common prefix before trimming it, so
out-of-tree module paths are shown as full absolute paths.
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
While looking at dynamic-debug-howto.txt, I noticed that it references
dev_debug() (which doesn't exist) instead of dev_dbg() (which does
exist). I'm lazy, so I choose to fix the document rather than changing
every dev_dbg() call.
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Add flags that allow the user to specify via debugfs whether or not the
module name, function name, line number and/or thread ID have to be
included in the printed message.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Greg Banks <gnb@fmeh.org>
Cc: Konrad Rzeszutek Wilk <konrad@darnok.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Dynamic debug lacks the ability to enable debug messages at boot time.
One could patch initramfs or service startup scripts to write to
/sys/../dynamic_debug/control, but this sucks.
This patch makes it possible to pass a query in the same format one can
write to /sys/../dynamic_debug/control via boot param.
When dynamic debug gets initialized, this query will automatically be
applied.
Signed-off-by: Thomas Renninger <trenn@suse.de>
Acked-by: jbaron@redhat.com
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Allow simple quoting of words in the dynamic debug control language.
This allows more natural specification when using the control language
to match against printk formats, e.g
#echo -n 'format "Setting node for non-present cpu" +p' >
/mnt/debugfs/dynamic_debug/control
instead of
#echo -n 'format Setting\040node\040for\040non-present\040cpu +p' >
/mnt/debugfs/dynamic_debug/control
Adjust the dynamic debug documention to describe that and provide a
new example. Adjust the existing examples in the documentation to
reflect the current whitespace escaping behaviour when reading the
control file. Fix some minor documentation trailing whitespace.
Signed-off-by: Greg Banks <gnb@melbourne.sgi.com>
Acked-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
