From 7a555613eb77c69eb6e48b61bc5f72dd42fa1780 Mon Sep 17 00:00:00 2001 From: Vladimir Kondratiev Date: Wed, 5 Dec 2012 16:48:27 -0500 Subject: [PATCH] dynamic_debug: dynamic hex dump 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 Signed-off-by: Jason Baron Signed-off-by: Greg Kroah-Hartman --- Documentation/dynamic-debug-howto.txt | 15 +++++++++++++-- include/linux/dynamic_debug.h | 11 +++++++++++ include/linux/printk.h | 17 +++++++++++++++++ lib/hexdump.c | 4 +++- 4 files changed, 44 insertions(+), 3 deletions(-) diff --git a/Documentation/dynamic-debug-howto.txt b/Documentation/dynamic-debug-howto.txt index 6e1684981da2..72322c6d7352 100644 --- a/Documentation/dynamic-debug-howto.txt +++ b/Documentation/dynamic-debug-howto.txt @@ -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). diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h index 6dd4787a798a..2fe93b26b42f 100644 --- a/include/linux/dynamic_debug.h +++ b/include/linux/dynamic_debug.h @@ -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 diff --git a/include/linux/printk.h b/include/linux/printk.h index 9afc01e5a0a6..02c95cf872cd 100644 --- a/include/linux/printk.h +++ b/include/linux/printk.h @@ -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 diff --git a/lib/hexdump.c b/lib/hexdump.c index 6540d657dca4..3f0494c9d57a 100644 --- a/lib/hexdump.c +++ b/lib/hexdump.c @@ -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) */ -- 2.30.2