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| author | Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com> | 2012-12-05 16:48:27 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-01-17 12:19:09 -0800 |
| commit | 7a555613eb77c69eb6e48b61bc5f72dd42fa1780 (patch) | |
| tree | fd2c5ef59a77ba532a5957923f9919fa170027f9 /Documentation/dynamic-debug-howto.txt | |
| parent | f657fd21e16e3ab7432c03008e19069c2ef8e150 (diff) | |
| download | lwn-7a555613eb77c69eb6e48b61bc5f72dd42fa1780.tar.gz lwn-7a555613eb77c69eb6e48b61bc5f72dd42fa1780.zip | |
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 <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/dynamic-debug-howto.txt')
| -rw-r--r-- | Documentation/dynamic-debug-howto.txt | 15 |
1 files changed, 13 insertions, 2 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). |