kpriv/linux-hardened
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

dynamic_debug: dynamic hex dump

Browse source 
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>
This commit is contained in:
Vladimir Kondratiev 2012-12-05 16:48:27 -05:00 committed by Greg Kroah-Hartman
parent f657fd21e1
commit 7a555613eb
4 changed files with 44 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

15
Documentation/dynamic-debug-howto.txt
View file

@ -6,8 +6,16 @@ This document describes how to use the dynamic debug (dyndbg) feature.
Dynamic debug is designed to allow you to dynamically enable/disable
kernel code to obtain additional kernel information. Currently, if
CONFIG_DYNAMIC_DEBUG is set, then all pr_debug()/dev_dbg() calls can
be dynamically enabled per-callsite.
CONFIG_DYNAMIC_DEBUG is set, then all pr_debug()/dev_dbg() and
print_hex_dump_debug()/print_hex_dump_bytes() calls can be dynamically
enabled per-callsite.
If CONFIG_DYNAMIC_DEBUG is not set, print_hex_dump_debug() is just
shortcut for print_hex_dump(KERN_DEBUG).
For print_hex_dump_debug()/print_hex_dump_bytes(), format string is
its 'prefix_str' argument, if it is constant string; or "hexdump"
in case 'prefix_str' is build dynamically.
Dynamic debug has even more useful features:
@ -202,6 +210,9 @@ The flags are:
t Include thread ID in messages not generated from interrupt context
_ No flags are set. (Or'd with others on input)
For print_hex_dump_debug() and print_hex_dump_bytes(), only 'p' flag
have meaning, other flags ignored.
For display, the flags are preceded by '='
(mnemonic: what the flags are currently equal to).

11
include/linux/dynamic_debug.h
View file

@ -95,6 +95,17 @@ do { \
##__VA_ARGS__); \
} while (0)
#define dynamic_hex_dump(prefix_str, prefix_type, rowsize, \
groupsize, buf, len, ascii) \
do { \
DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, \
__builtin_constant_p(prefix_str) ? prefix_str : "hexdump");\
if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT)) \
print_hex_dump(KERN_DEBUG, prefix_str, \
prefix_type, rowsize, groupsize, \
buf, len, ascii); \
} while (0)
#else
#include <linux/string.h>

17
include/linux/printk.h
View file

@ -321,8 +321,13 @@ extern void hex_dump_to_buffer(const void *buf, size_t len,
extern void print_hex_dump(const char *level, const char *prefix_str,
int prefix_type, int rowsize, int groupsize,
const void *buf, size_t len, bool ascii);
#if defined(CONFIG_DYNAMIC_DEBUG)
#define print_hex_dump_bytes(prefix_str, prefix_type, buf, len) \
dynamic_hex_dump(prefix_str, prefix_type, 16, 1, buf, len, true)
#else
extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
const void *buf, size_t len);
#endif /* defined(CONFIG_DYNAMIC_DEBUG) */
#else
static inline void print_hex_dump(const char *level, const char *prefix_str,
int prefix_type, int rowsize, int groupsize,
@ -336,4 +341,16 @@ static inline void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
#endif
#if defined(CONFIG_DYNAMIC_DEBUG)
#define print_hex_dump_debug(prefix_str, prefix_type, rowsize, \
groupsize, buf, len, ascii) \
dynamic_hex_dump(prefix_str, prefix_type, rowsize, \
groupsize, buf, len, ascii)
#else
#define print_hex_dump_debug(prefix_str, prefix_type, rowsize, \
groupsize, buf, len, ascii) \
print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, rowsize, \
groupsize, buf, len, ascii)
#endif /* defined(CONFIG_DYNAMIC_DEBUG) */
#endif

4
lib/hexdump.c
View file

@ -227,6 +227,7 @@ void print_hex_dump(const char *level, const char *prefix_str, int prefix_type,
}
EXPORT_SYMBOL(print_hex_dump);
#if !defined(CONFIG_DYNAMIC_DEBUG)
/**
* print_hex_dump_bytes - shorthand form of print_hex_dump() with default params
* @prefix_str: string to prefix each line with;
@ -246,4 +247,5 @@ void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
buf, len, true);
}
EXPORT_SYMBOL(print_hex_dump_bytes);
#endif
#endif /* !defined(CONFIG_DYNAMIC_DEBUG) */
#endif /* defined(CONFIG_PRINTK) */