summaryrefslogtreecommitdiff
path: root/Documentation/printk-formats.txt
AgeCommit message (Collapse)Author
2016-03-15mm, printk: introduce new format string for flagsVlastimil Babka
In mm we use several kinds of flags bitfields that are sometimes printed for debugging purposes, or exported to userspace via sysfs. To make them easier to interpret independently on kernel version and config, we want to dump also the symbolic flag names. So far this has been done with repeated calls to pr_cont(), which is unreliable on SMP, and not usable for e.g. sysfs export. To get a more reliable and universal solution, this patch extends printk() format string for pointers to handle the page flags (%pGp), gfp_flags (%pGg) and vma flags (%pGv). Existing users of dump_flag_names() are converted and simplified. It would be possible to pass flags by value instead of pointer, but the %p format string for pointers already has extensions for various kernel structures, so it's a good fit, and the extra indirection in a non-critical path is negligible. [linux@rasmusvillemoes.dk: lots of good implementation suggestions] Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16printk-formats.txt: remove unimplemented %pTRasmus Villemoes
%pT for task->comm has been proposed (several times, I think), but is not actually implemented. Remove it from printk-formats.txt and add it back if/when it gets implemented. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-06lib/vsprintf: add %*pg format specifierDmitry Monakhov
This allow to directly print block_device name. Currently one should use bdevname() with temporal char buffer. This is very ineffective because bloat stack usage for deep IO call-traces Example: %pg -> sda, sda1 or loop0p1 [AV: fixed a minor braino - position updates should not be dependent upon having reached the of buffer] Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-11-06lib/vsprintf.c: update documentationRasmus Villemoes
%n is no longer just ignored; it results in early return from vsnprintf. Also add a request to add test cases for future %p extensions. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Reviewed-by: Martin Kletzander <mkletzan@redhat.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-06printk: synchronize %p formatting documentationMartin Kletzander
Move all pointer-formatting documentation to one place in the code and one place in the documentation instead of keeping it in three places with different level of completeness. Documentation/printk-formats.txt has detailed information about each modifier, docstring above pointer() has short descriptions of them (as that is the function dealing with %p) and docstring above vsprintf() is removed as redundant. Both docstrings in the code that were modified are updated with a reminder of updating the documentation upon any further change. [akpm@linux-foundation.org: fix comment] Signed-off-by: Martin Kletzander <mkletzan@redhat.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-18Merge tag 'docs-for-linus' of git://git.lwn.net/linux-2.6Linus Torvalds
Pull documentation updates from Jonathan Corbet: "Numerous fixes, the overdue removal of the i2o docs, some new Chinese translations, and, hopefully, the README fix that will end the flow of identical patches to that file" * tag 'docs-for-linus' of git://git.lwn.net/linux-2.6: (34 commits) Documentation/memcg: update memcg/kmem status Documentation: blackfin: Makefile: Typo building issue Documentation/vm/pagemap.txt: correct location of page-types tool Documentation/memory-barriers.txt: typo fix doc: Add guest_nice column to example output of `cat /proc/stat' Documentation/kernel-parameters: Move "eagerfpu" to its right place Documentation: gpio: Update ACPI part of the document to mention _DSD docs/completion.txt: Various tweaks and corrections doc: completion: context, scope and language fixes Documentation:Update Documentation/zh_CN/arm64/memory.txt Documentation:Update Documentation/zh_CN/arm64/booting.txt Documentation: Chinese translation of arm64/legacy_instructions.txt DocBook media: fix broken EIA hyperlink Documentation: tweak the maintainers entry README: Change gzip/bzip2 to xz compression format README: Update version number reference doc:pci: Fix typo in Documentation/PCI Documentation: drm: Use '->' when describing access through pointers. Documentation: Remove mentioning of block barriers Documentation/email-clients.txt: Fix one grammar mistake, add extra info about TB ...
2015-04-15lib/vsprintf: add %pC{,n,r} format specifiers for clocksGeert Uytterhoeven
Add format specifiers for printing struct clk: - '%pC' or '%pCn': name (Common Clock Framework) or address (legacy clock framework) of the clock, - '%pCr': rate of the clock. [akpm@linux-foundation.org: omit code if !CONFIG_HAVE_CLK] Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mike Turquette <mturquette@linaro.org> Cc: Stephen Boyd <sboyd@codeaurora.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15lib/vsprintf: Move integer format types to the topGeert Uytterhoeven
Move the format types for 64-bit integers and configurable size integers to the top, so they're next to the other integer format types. While at it, add the missing format types for s32 and u32. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mike Turquette <mturquette@linaro.org> Cc: Stephen Boyd <sboyd@codeaurora.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15lib/vsprintf: document %p parameters passed by referenceGeert Uytterhoeven
This patch series improves the documentation for printk() formats, and adds support for printing clocks. The latter has always been a hassle if you wanted to support both the common and legacy clock frameworks. - '%pC' and '%pCn' print the name (Common Clock Framework) or address (legacy clock framework) of a clock, - '%pCr' prints the current clock rate. This patch (of 3): Make sure all %p extensions that take parameters by references are documented to do so. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mike Turquette <mturquette@linaro.org> Cc: Stephen Boyd <sboyd@codeaurora.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-03-20doc: printk-formats: Fix %pU descriptionRasmus Villemoes
The documentation and the code disagrees; fix the former. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2015-03-20Documentation: add print bitmap descriptionWang Long
as the commit: "lib/vsprintf: implement bitmap printing through '%*pb[l]'" add an easy way to print bitmaps. so printk-formats.txt should reflect it. Signed-off-by: Wang Long <long.wanglong@huawei.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2014-10-14lib/vsprintf: add %*pE[achnops] format specifierAndy Shevchenko
This allows user to print a given buffer as an escaped string. The rules are applied according to an optional mix of flags provided by additional format letters. For example, if the given buffer is: 1b 62 20 5c 43 07 22 90 0d 5d The result strings would be: %*pE "\eb \C\a"\220\r]" %*pEhp "\x1bb \C\x07"\x90\x0d]" %*pEa "\e\142\040\\\103\a\042\220\r\135" Please, read Documentation/printk-formats.txt and lib/string_helpers.c kernel documentation to get further information. [akpm@linux-foundation.org: tidy up comment layout, per Joe] Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Suggested-by: Joe Perches <joe@perches.com> Cc: "John W . Linville" <linville@tuxdriver.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-05-05doc: printk-formats: do not mention casts for u64/s64Ilya Dryomov
Do not mention casts for u64/s64. Complements commit 2a7930bd77fe ("Documentation/printk-formats.txt: No casts needed for u64/s64"). Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-01-23vsprintf: add %pad extension for dma_addr_t useJoe Perches
dma_addr_t's can be either u32 or u64 depending on a CONFIG option. There are a few hundred dma_addr_t's printed via either cast to unsigned long long, unsigned long or no cast at all. Add %pad to be able to emit them without the cast. Update Documentation/printk-formats.txt too. Signed-off-by: Joe Perches <joe@perches.com> Cc: "Shevchenko, Andriy" <andriy.shevchenko@intel.com> Cc: Rob Landley <rob@landley.net> Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Cc: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-06Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial tree from Jiri Kosina: "The usual trivial updates all over the tree -- mostly typo fixes and documentation updates" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (52 commits) doc: Documentation/cputopology.txt fix typo treewide: Convert retrun typos to return Fix comment typo for init_cma_reserved_pageblock Documentation/trace: Correcting and extending tracepoint documentation mm/hotplug: fix a typo in Documentation/memory-hotplug.txt power: Documentation: Update s2ram link doc: fix a typo in Documentation/00-INDEX Documentation/printk-formats.txt: No casts needed for u64/s64 doc: Fix typo "is is" in Documentations treewide: Fix printks with 0x%# zram: doc fixes Documentation/kmemcheck: update kmemcheck documentation doc: documentation/hwspinlock.txt fix typo PM / Hibernate: add section for resume options doc: filesystems : Fix typo in Documentations/filesystems scsi/megaraid fixed several typos in comments ppc: init_32: Fix error typo "CONFIG_START_KERNEL" treewide: Add __GFP_NOWARN to k.alloc calls with v.alloc fallbacks page_isolation: Fix a comment typo in test_pages_isolated() doc: fix a typo about irq affinity ...
2013-09-04add formats for dentry/file pathnamesAl Viro
New formats: %p[dD][234]?. The next pointer is interpreted as struct dentry * or struct file * resp. ('d' => dentry, 'D' => file) and the last component(s) of pathname are printed (%pd => just the last one, %pd2 => the last two, etc.) Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-08-27Documentation/printk-formats.txt: No casts needed for u64/s64Geert Uytterhoeven
Now all 64-bit architectures have been converted to int-ll64.h in kernel space, casting to (unsigned) long long is no longer needed when formatting u64/s64. For backwards compatibility, alpha, ia64, mips64, and powerpc64 still use int-l64.h in userspace. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Acked-by: Rob Landley <rob@landley.net> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-07-25Merge branch 'master' into for-nextJiri Kosina
Sync with Linus' master to be able to apply trivial patche to newer code. Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-07-08doc: printk-formats: fix format specifier to %p[Ii]4[hnbl]Daniel Borkmann
This might have been an oversight, as '4' is needed as %pI4/%pi4 are format specifiers and [hnbl] are extensions of it. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> CC: Joe Perches <joe@perches.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-07-01lib: vsprintf: add IPv4/v6 generic %p[Ii]S[pfs] format specifierDaniel Borkmann
In order to avoid making code that deals with printing both, IPv4 and IPv6 addresses, unnecessary complicated as for example ... if (sa.sa_family == AF_INET6) printk("... %pI6 ...", ..sin6_addr); else printk("... %pI4 ...", ..sin_addr.s_addr); ... it would be better to introduce a format specifier that can deal with those kind of situations internally; just as we have a "struct sockaddr" for generic mapping into "struct sockaddr_in" or "struct sockaddr_in6" as e.g. done in "union sctp_addr". Then, we could reduce the above statement into something like: printk("... %pIS ..", &sockaddr); In case our pointer is NULL, pointer() then deals with that already at an earlier point in time internally. While we're at it, support for both %piS/%pIS, where 'S' stands for sockaddr, comes (almost) for free. Additionally to that, postfix specifiers 'p', 'f' and 's' are supported as suggested and initially implemented in 2009 by Joe Perches [1]. Handling of those additional specifiers orientate on the initial RFC that was proposed. Also we support IPv6 compressed format specified by 'c' and various other IPv4 extensions as stated in the documentation part. Likely, there are many other areas than just SCTP in the kernel to make use of this extension as well. [1] http://patchwork.ozlabs.org/patch/31480/ Signed-off-by: Daniel Borkmann <dborkman@redhat.com> CC: Joe Perches <joe@perches.com> CC: linux-kernel@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-30Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull fixup for trivial branch from Jiri Kosina: "Unfortunately I made a mistake when merging into for-linus branch, and omitted one pre-requisity patch for a few other patches (which have been Acked by the appropriate maintainers) in the series. Mea culpa maxima, sorry for that." The trivial branch added %pSR usage before actually teaching vsnprintf() about the 'R' part of %pSR. The 'R' causes the symbol translation to do a "__builtin_extract_return_addr()" before symbol lookup. That said, on most architectures __builtin_extract_return_addr() isn't likely to do anything special, so it probably is not normally noticeable. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: vsprintf: Add extension %pSR - print_symbol replacement
2013-04-30vsprintf: Add extension %pSR - print_symbol replacementJoe Perches
print_symbol takes a long and converts it to a function name and offset. %pS does something similar, but doesn't translate the address via __builtin_extract_return_addr. %pSR does the translation. This will enable replacing multiple calls like printk(...); printk_symbol(addr); printk("\n"); with a single non-interleavable in dmesg printk("... %pSR\n", (void *)addr); Update documentation too. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-03-08Randy has movedRandy Dunlap
Update email address and CREDITS info. xenotime.net is defunct. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Harry Wei <harryxiyou@gmail.com> Cc: Keiichi KII <k-keiichi@bx.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-21lib/vsprintf.c: add %pa format specifier for phys_addr_t typesStepan Moskovchenko
Add the %pa format specifier for printing a phys_addr_t type and its derivative types (such as resource_size_t), since the physical address size on some platforms can vary based on build options, regardless of the native integer type. Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org> Cc: Rob Landley <rob@landley.net> Cc: George Spelvin <linux@horizon.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Stephen Boyd <sboyd@codeaurora.org> Cc: Andrei Emeltchenko <andrei.emeltchenko@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-06lib/vsprintf: update documentation to cover all of %p[Mm][FR]Andy Shevchenko
Acked-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30vsprintf: add support of '%*ph[CDN]'Andy Shevchenko
There are many places in the kernel where the drivers print small buffers as a hex string. This patch adds a support of the variable width buffer to print it as a hex string with a delimiter. The idea came from Pavel Roskin here: http://www.digipedia.pl/usenet/thread/18835/17449/ Sample output of pr_info("buf[%d:%d] %*phC\n", from, len, len, &buf[from]); could be look like this: [ 0.726130] buf[51:8] e8:16:b6:ef:e3:74:45:6e [ 0.750736] buf[59:15] 31:81:b8:3f:35:49:06:ae:df:32:06:05:4a:af:55 [ 0.757602] buf[17:5] ac:16:d5:2c:ef Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30vsprintf: add %pMR for Bluetooth MAC addressAndrei Emeltchenko
Bluetooth uses mostly LE byte order which is reversed for visual interpretation. Currently in Bluetooth in use unsafe batostr function. This is a slightly modified version of Joe's patch (sent Sat, Dec 4, 2010). Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com> Cc: Joe Perches <joe@perches.com> Cc: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-06-15Documentation: update printk-formats.txtAndrew Murray
This patch updates the incomplete documentation concerning the printk extended format specifiers. Signed-off-by: Andrew Murray <amurray@mpc-data.co.uk> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-12DOC: add printk-formats.txtRandy Dunlap
Add printk-formats.txt so that we don't have to keep fixing the same things over and over again. <wishful thinking> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>