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2020-08-04Merge tag 'docs-5.9' of git://git.lwn.net/linuxLinus Torvalds
Pull documentation updates from Jonathan Corbet: "It's been a busy cycle for documentation - hopefully the busiest for a while to come. Changes include: - Some new Chinese translations - Progress on the battle against double words words and non-HTTPS URLs - Some block-mq documentation - More RST conversions from Mauro. At this point, that task is essentially complete, so we shouldn't see this kind of churn again for a while. Unless we decide to switch to asciidoc or something...:) - Lots of typo fixes, warning fixes, and more" * tag 'docs-5.9' of git://git.lwn.net/linux: (195 commits) scripts/kernel-doc: optionally treat warnings as errors docs: ia64: correct typo mailmap: add entry for <alobakin@marvell.com> doc/zh_CN: add cpu-load Chinese version Documentation/admin-guide: tainted-kernels: fix spelling mistake MAINTAINERS: adjust kprobes.rst entry to new location devices.txt: document rfkill allocation PCI: correct flag name docs: filesystems: vfs: correct flag name docs: filesystems: vfs: correct sync_mode flag names docs: path-lookup: markup fixes for emphasis docs: path-lookup: more markup fixes docs: path-lookup: fix HTML entity mojibake CREDITS: Replace HTTP links with HTTPS ones docs: process: Add an example for creating a fixes tag doc/zh_CN: add Chinese translation prefer section doc/zh_CN: add clearing-warn-once Chinese version doc/zh_CN: add admin-guide index doc:it_IT: process: coding-style.rst: Correct __maybe_unused compiler label futex: MAINTAINERS: Re-add selftests directory ...
2020-07-23docs: core-api/printk-formats.rst: use literal block syntaxDaniel W. S. Almeida
Fix the following warning: WARNING: Definition list ends without a blank line; unexpected unindent. By switching to the literal block syntax. Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com> Link: https://lore.kernel.org/r/20200718165107.625847-8-dwlsalmeida@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-03Replace HTTP links with HTTPS ones: vsprintfAlexander A. Klimov
Rationale: Reduces attack surface on kernel devs opening the links for MITM as HTTPS traffic is much harder to manipulate. Deterministic algorithm: For each file: If not .svg: For each line: If doesn't contain `\bxmlns\b`: For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`: If both the HTTP and HTTPS versions return 200 OK and serve the same content: Replace HTTP with HTTPS. Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20200702200536.13389-1-grandmaster@al2klimov.de
2020-06-01Merge tag 'docs-5.8' of git://git.lwn.net/linuxLinus Torvalds
Pull documentation updates from Jonathan Corbet: "A fair amount of stuff this time around, dominated by yet another massive set from Mauro toward the completion of the RST conversion. I *really* hope we are getting close to the end of this. Meanwhile, those patches reach pretty far afield to update document references around the tree; there should be no actual code changes there. There will be, alas, more of the usual trivial merge conflicts. Beyond that we have more translations, improvements to the sphinx scripting, a number of additions to the sysctl documentation, and lots of fixes" * tag 'docs-5.8' of git://git.lwn.net/linux: (130 commits) Documentation: fixes to the maintainer-entry-profile template zswap: docs/vm: Fix typo accept_threshold_percent in zswap.rst tracing: Fix events.rst section numbering docs: acpi: fix old http link and improve document format docs: filesystems: add info about efivars content Documentation: LSM: Correct the basic LSM description mailmap: change email for Ricardo Ribalda docs: sysctl/kernel: document unaligned controls Documentation: admin-guide: update bug-hunting.rst docs: sysctl/kernel: document ngroups_max nvdimm: fixes to maintainter-entry-profile Documentation/features: Correct RISC-V kprobes support entry Documentation/features: Refresh the arch support status files Revert "docs: sysctl/kernel: document ngroups_max" docs: move locking-specific documents to locking/ docs: move digsig docs to the security book docs: move the kref doc into the core-api book docs: add IRQ documentation at the core-api book docs: debugging-via-ohci1394.txt: add it to the core-api book docs: fix references for ipmi.rst file ...
2020-06-01Merge tag 'printk-for-5.8' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux Pull printk updates from Petr Mladek: - Benjamin Herrenschmidt solved a problem with non-matched console aliases by first checking consoles defined on the command line. It is a more conservative approach than the previous attempts. - Benjamin also made sure that the console accessible via /dev/console always has CON_CONSDEV flag. - Andy Shevchenko added the %ptT modifier for printing struct time64_t. It extends the existing %ptR handling for struct rtc_time. - Bruno Meneguele fixed /dev/kmsg error value returned by unsupported SEEK_CUR. - Tetsuo Handa removed unused pr_cont_once(). ... and a few small fixes. * tag 'printk-for-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: printk: Remove pr_cont_once() printk: handle blank console arguments passed in. kernel/printk: add kmsg SEEK_CUR handling printk: Fix a typo in comment "interator"->"iterator" usb: pulse8-cec: Switch to use %ptT ARM: bcm2835: Switch to use %ptT lib/vsprintf: Print time64_t in human readable format lib/vsprintf: update comment about simple_strto<foo>() functions printk: Correctly set CON_CONSDEV even when preferred console was not registered printk: Fix preferred console selection with multiple matches printk: Move console matching logic into a separate function printk: Convert a use of sprintf to snprintf in console_unlock
2020-05-20lib/vsprintf: Print time64_t in human readable formatAndy Shevchenko
There are users which print time and date represented by content of time64_t type in human readable format. Instead of open coding that each time introduce %ptT[dt][r] specifier. Few test cases for %ptT specifier has been added as well. Link: https://lore.kernel.org/r/20200415170046.33374-2-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Rewieved-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2020-05-15bpf: Restrict bpf_trace_printk()'s %s usage and add %pks, %pus specifierDaniel Borkmann
Usage of plain %s conversion specifier in bpf_trace_printk() suffers from the very same issue as bpf_probe_read{,str}() helpers, that is, it is broken on archs with overlapping address ranges. While the helpers have been addressed through work in 6ae08ae3dea2 ("bpf: Add probe_read_{user, kernel} and probe_read_{user, kernel}_str helpers"), we need an option for bpf_trace_printk() as well to fix it. Similarly as with the helpers, force users to make an explicit choice by adding %pks and %pus specifier to bpf_trace_printk() which will then pick the corresponding strncpy_from_unsafe*() variant to perform the access under KERNEL_DS or USER_DS. The %pk* (kernel specifier) and %pu* (user specifier) can later also be extended for other objects aside strings that are probed and printed under tracing, and reused out of other facilities like bpf_seq_printf() or BTF based type printing. Existing behavior of %s for current users is still kept working for archs where it is not broken and therefore gated through CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE. For archs not having this property we fall-back to pick probing under KERNEL_DS as a sensible default. Fixes: 8d3b7dce8622 ("bpf: add support for %s specifier to bpf_trace_printk()") Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Link: https://lore.kernel.org/bpf/20200515101118.6508-4-daniel@iogearbox.net
2020-04-20docs: pr_*() kerneldocs and basic printk docsRicardo Cañuelo
Add kerneldocs comments to the pr_*() macros in printk.h. Add a new rst node in the core-api manual describing the basic usage of printk and the related macro aliases. Signed-off-by: Ricardo Cañuelo <ricardo.canuelo@collabora.com> Link: https://lore.kernel.org/r/20200403093617.18003-1-ricardo.canuelo@collabora.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-12-02Merge tag 'docs-5.5a' of git://git.lwn.net/linuxLinus Torvalds
Pull Documentation updates from Jonathan Corbet: "Here are the main documentation changes for 5.5: - Various kerneldoc script enhancements. - More RST conversions; those are slowing down as we run out of things to convert, but we're a ways from done still. - Dan's "maintainer profile entry" work landed at last. Now we just need to get maintainers to fill in the profiles... - A reworking of the parallel build setup to work better with a variety of systems (and to not take over huge systems entirely in particular). - The MAINTAINERS file is now converted to RST during the build. Hopefully nobody ever tries to print this thing, or they will need to load a lot of paper. - A script and documentation making it easy for maintainers to add Link: tags at commit time. Also included is the removal of a bunch of spurious CR characters" * tag 'docs-5.5a' of git://git.lwn.net/linux: (91 commits) docs: remove a bunch of stray CRs docs: fix up the maintainer profile document libnvdimm, MAINTAINERS: Maintainer Entry Profile Maintainer Handbook: Maintainer Entry Profile MAINTAINERS: Reclaim the P: tag for Maintainer Entry Profile docs, parallelism: Rearrange how jobserver reservations are made docs, parallelism: Do not leak blocking mode to other readers docs, parallelism: Fix failure path and add comment Documentation: Remove bootmem_debug from kernel-parameters.txt Documentation: security: core.rst: fix warnings Documentation/process/howto/kokr: Update for 4.x -> 5.x versioning Documentation/translation: Use Korean for Korean translation title docs/memory-barriers.txt: Remove remaining references to mmiowb() docs/memory-barriers.txt/kokr: Update I/O section to be clearer about CPU vs thread docs/memory-barriers.txt/kokr: Fix style, spacing and grammar in I/O section Documentation/kokr: Kill all references to mmiowb() docs/memory-barriers.txt/kokr: Rewrite "KERNEL I/O BARRIER EFFECTS" section docs: Add initial documentation for devfreq Documentation: Document how to get links with git am docs: Add request_irq() documentation ...
2019-11-26Merge tag 'devprop-5.5-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull device properties framework updates from Rafael Wysocki: "Add support for printing fwnode names using a new conversion specifier "%pfw" (Sakari Ailus), clean up the software node and efi/apple-properties code in preparation for improved software node reference properties handling (Dmitry Torokhov) and fix the struct fwnode_operations description (Heikki Krogerus)" * tag 'devprop-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (22 commits) software node: simplify property_entry_read_string_array() software node: unify PROPERTY_ENTRY_XXX macros software node: remove property_entry_read_uNN_array functions software node: get rid of property_set_pointer() software node: clean up property_copy_string_array() software node: mark internal macros with double underscores efi/apple-properties: use PROPERTY_ENTRY_U8_ARRAY_LEN software node: introduce PROPERTY_ENTRY_XXX_ARRAY_LEN() software node: remove DEV_PROP_MAX device property: Fix the description of struct fwnode_operations lib/test_printf: Add tests for %pfw printk modifier lib/vsprintf: Add %pfw conversion specifier for printing fwnode names lib/vsprintf: OF nodes are first and foremost, struct device_nodes lib/vsprintf: Make use of fwnode API to obtain node names and separators lib/vsprintf: Add a note on re-using %pf or %pF lib/vsprintf: Remove support for %pF and %pf in favour of %pS and %ps device property: Add a function to obtain a node's prefix device property: Add fwnode_get_name for returning the name of a node device property: Add functions for accessing node's parents device property: Move fwnode_get_parent() up ...
2019-11-25Merge tag 'printk-for-5.5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk Pull printk updates from Petr Mladek: - Allow to print symbolic error names via new %pe modifier. - Use pr_warn() instead of the remaining pr_warning() calls. Fix formatting of the related lines. - Add VSPRINTF entry to MAINTAINERS. * tag 'printk-for-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: (32 commits) checkpatch: don't warn about new vsprintf pointer extension '%pe' MAINTAINERS: Add VSPRINTF tools lib api: Renaming pr_warning to pr_warn ASoC: samsung: Use pr_warn instead of pr_warning lib: cpu_rmap: Use pr_warn instead of pr_warning trace: Use pr_warn instead of pr_warning dma-debug: Use pr_warn instead of pr_warning vgacon: Use pr_warn instead of pr_warning fs: afs: Use pr_warn instead of pr_warning sh/intc: Use pr_warn instead of pr_warning scsi: Use pr_warn instead of pr_warning platform/x86: intel_oaktrail: Use pr_warn instead of pr_warning platform/x86: asus-laptop: Use pr_warn instead of pr_warning platform/x86: eeepc-laptop: Use pr_warn instead of pr_warning oprofile: Use pr_warn instead of pr_warning of: Use pr_warn instead of pr_warning macintosh: Use pr_warn instead of pr_warning idsn: Use pr_warn instead of pr_warning ide: Use pr_warn instead of pr_warning crypto: n2: Use pr_warn instead of pr_warning ...
2019-11-07docs: printk-formats: add ptrdiff_t type to printk-formatsMiles Chen
When print the difference between two pointers, we should use the ptrdiff_t modifier %t. Signed-off-by: Miles Chen <miles.chen@mediatek.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-10-17printf: add support for printing symbolic error namesRasmus Villemoes
It has been suggested several times to extend vsnprintf() to be able to convert the numeric value of ENOSPC to print "ENOSPC". This implements that as a %p extension: With %pe, one can do if (IS_ERR(foo)) { pr_err("Sorry, can't do that: %pe\n", foo); return PTR_ERR(foo); } instead of what is seen in quite a few places in the kernel: if (IS_ERR(foo)) { pr_err("Sorry, can't do that: %ld\n", PTR_ERR(foo)); return PTR_ERR(foo); } If the value passed to %pe is an ERR_PTR, but the library function errname() added here doesn't know about the value, the value is simply printed in decimal. If the value passed to %pe is not an ERR_PTR, we treat it as an ordinary %p and thus print the hashed value (passing non-ERR_PTR values to %pe indicates a bug in the caller, but we can't do much about that). With my embedded hat on, and because it's not very invasive to do, I've made it possible to remove this. The errname() function and associated lookup tables take up about 3K. For most, that's probably quite acceptable and a price worth paying for more readable dmesg (once this starts getting used), while for those that disable printk() it's of very little use - I don't see a procfs/sysfs/seq_printf() file reasonably making use of this - and they clearly want to squeeze vmlinux as much as possible. Hence the default y if PRINTK. The symbols to include have been found by massaging the output of find arch include -iname 'errno*.h' | xargs grep -E 'define\s*E' In the cases where some common aliasing exists (e.g. EAGAIN=EWOULDBLOCK on all platforms, EDEADLOCK=EDEADLK on most), I've moved the more popular one (in terms of 'git grep -w Efoo | wc) to the bottom so that one takes precedence. Link: http://lkml.kernel.org/r/20191015190706.15989-1-linux@rasmusvillemoes.dk To: "Jonathan Corbet" <corbet@lwn.net> To: linux-kernel@vger.kernel.org Cc: "Andy Shevchenko" <andy.shevchenko@gmail.com> Cc: "Andrew Morton" <akpm@linux-foundation.org> Cc: "Joe Perches" <joe@perches.com> Cc: linux-doc@vger.kernel.org Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Acked-by: Uwe Kleine-König <uwe@kleine-koenig.org> Reviewed-by: Petr Mladek <pmladek@suse.com> [andy.shevchenko@gmail.com: use abs()] Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-10-11lib/vsprintf: Add %pfw conversion specifier for printing fwnode namesSakari Ailus
Add support for %pfw conversion specifier (with "f" and "P" modifiers) to support printing full path of the node, including its name ("f") and only the node's name ("P") in the printk family of functions. The two flags have equivalent functionality to existing %pOF with the same two modifiers ("f" and "P") on OF based systems. The ability to do the same on ACPI based systems is added by this patch. On ACPI based systems the resulting strings look like \_SB.PCI0.CIO2.port@1.endpoint@0 where the nodes are separated by a dot (".") and the first three are ACPI device nodes and the latter two ACPI data nodes. Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-10-11lib/vsprintf: Remove support for %pF and %pf in favour of %pS and %psSakari Ailus
%pS and %ps are now the preferred conversion specifiers to print function names. The functionality is equivalent; remove the old, deprecated %pF and %pf support. Depends-on: commit 2d44d165e939 ("scsi: lpfc: Convert existing %pf users to %ps") Depends-on: commit b295c3e39c13 ("tools lib traceevent: Convert remaining %p[fF] users to %p[sS]") Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-09-14docs: printk-formats: Stop encouraging use of unnecessary %h[xudi] and %hh[xudi]Joe Perches
Standard integer promotion is already done and %hx and %hhx is useless so do not encourage the use of %hh[xudi] or %h[xudi]. As Linus said in: https://lore.kernel.org/lkml/CAHk-=wgoxnmsj8GEVFJSvTwdnWm8wVJthefNk2n6+4TC=20e0Q@mail.gmail.com/ It's a pointless warning, making for more complex code, and making people remember esoteric printf format details that have no reason for existing. The "h" and "hh" things should never be used. The only reason for them being used if if you have an "int", but you want to print it out as a "char" (and honestly, that is a really bad reason, you'd be better off just using a proper cast to make the code more obvious). So if what you have a "char" (or unsigned char) you should always just print it out as an "int", knowing that the compiler already did the proper type conversion. Signed-off-by: Joe Perches <joe@perches.com> Reviewed-by: Louis Taylor <louis@kragniz.eu> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-15docs: admin-guide: move sysctl directory to itMauro Carvalho Chehab
The stuff under sysctl describes /sys interface from userspace point of view. So, add it to the admin-guide and remove the :orphan: from its index file. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-07-15docs: sysctl: convert to ReSTMauro Carvalho Chehab
Rename the /proc/sys/ documentation files to ReST, using the README file as a template for an index.rst, adding the other files there via TOC markup. Despite being written on different times with different styles, try to make them somewhat coherent with a similar look and feel, ensuring that they'll look nice as both raw text file and as via the html output produced by the Sphinx build system. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-04-26vsprintf: Avoid confusion between invalid address and valuePetr Mladek
We are able to detect invalid values handled by %p[iI] printk specifier. The current error message is "invalid address". It might cause confusion against "(efault)" reported by the generic valid_pointer_address() check. Let's unify the style and use the more appropriate error code description "(einval)". Link: http://lkml.kernel.org/r/20190417115350.20479-10-pmladek@suse.com To: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Tobin C . Harding" <me@tobin.cc> Cc: Joe Perches <joe@perches.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-04-26vsprintf: Prevent crash when dereferencing invalid pointersPetr Mladek
We already prevent crash when dereferencing some obviously broken pointers. But the handling is not consistent. Sometimes we print "(null)" only for pure NULL pointer, sometimes for pointers in the first page and sometimes also for pointers in the last page (error codes). Note that printk() call this code under logbuf_lock. Any recursive printks are redirected to the printk_safe implementation and the messages are stored into per-CPU buffers. These buffers might be eventually flushed in printk_safe_flush_on_panic() but it is not guaranteed. This patch adds a check using probe_kernel_read(). It is not a full-proof test. But it should help to see the error message in 99% situations where the kernel would silently crash otherwise. Also it makes the error handling unified for "%s" and the many %p* specifiers that need to read the data from a given address. We print: + (null) when accessing data on pure pure NULL address + (efault) when accessing data on an invalid address It does not affect the %p* specifiers that just print the given address in some form, namely %pF, %pf, %pS, %ps, %pB, %pK, %px, and plain %p. Note that we print (efault) from security reasons. In fact, the real address can be seen only by %px or eventually %pK. Link: http://lkml.kernel.org/r/20190417115350.20479-9-pmladek@suse.com To: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Tobin C . Harding" <me@tobin.cc> Cc: Joe Perches <joe@perches.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-03-09Merge tag 'printk-for-5.1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk Pull printk updates from Petr Mladek: - Allow to sort mixed lines by an extra information about the caller - Remove no longer used LOG_PREFIX. - Some clean up and documentation update. * tag 'printk-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: printk/docs: Add extra integer types to printk-formats printk: Remove no longer used LOG_PREFIX. lib/vsprintf: Remove %pCr remnant in comment printk: Pass caller information to log_store(). printk: Add caller information to printk() output.
2019-03-04printk/docs: Add extra integer types to printk-formatsLouis Taylor
A few commonly used integer types were absent from this table, so add them. Link: https://github.com/ClangBuiltLinux/linux/issues/378 Suggested-by: Nick Desaulniers <ndesaulniers@google.com> Link: http://lkml.kernel.org/r/20190303123647.22020-1-louis@kragniz.eu Cc: pmladek@suse.com Cc: geert+renesas@glider.be Cc: andriy.shevchenko@linux.intel.com Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: clang-built-linux@googlegroups.com Cc: ndesaulniers@google.com Cc: jflat@chromium.org Cc: Louis Taylor <louis@kragniz.eu> Signed-off-by: Louis Taylor <louis@kragniz.eu> [pmladek@suse.com: sorted both variants the same way by size] Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-12-10lib/vsprintf: Print time and date in human readable format via %ptAndy Shevchenko
There are users which print time and date represented by content of struct rtc_time in human readable format. Instead of open coding that each time introduce %ptR[dt][r] specifier. Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: Krzysztof Kozlowski <krzk@kernel.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Petr Mladek <pmladek@suse.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-10-25Merge tag 'printk-for-4.20' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk Pull printk updates from Petr Mladek: - Fix two more locations where printf formatting leaked pointers - Better log_buf_len parameter handling - Add prefix to messages from printk code - Do not miss messages on other consoles when the log is replayed on a new one - Reduce race between console registration and panic() when the log might get replayed on all consoles - Some cont buffer code clean up - Call console only when there is something to do (log vs cont buffer) * tag 'printk-for-4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: lib/vsprintf: Hash printed address for netdev bits fallback lib/vsprintf: Hash legacy clock addresses lib/vsprintf: Prepare for more general use of ptr_to_id() lib/vsprintf: Make ptr argument conts in ptr_to_id() printk: fix integer overflow in setup_log_buf() printk: do not preliminary split up cont buffer printk: lock/unlock console only for new logbuf entries printk: keep kernel cont support always enabled printk: Give error on attempt to set log buffer length to over 2G printk: Add KBUILD_MODNAME and remove a redundant print prefix printk: Correct wrong casting printk: Fix panic caused by passing log_buf_len to command line printk: CON_PRINTBUFFER console registration is a bit racy printk: Do not miss new messages when replaying the log
2018-10-12doc: printk-formats: Remove bogus kobject references for device nodesGeert Uytterhoeven
When converting from text to rst, the kobjects section and its sole subsection about device tree nodes were coalesced into a single section, yielding an inconsistent result. Remove all references to kobjects, as 1. Device tree object pointers are not compatible to kobject pointers (the former may embed the latter, though), and 2. there are no printk formats defined for kobject types. Update the vsprintf() source code comments to match the above. Fixes: b3ed23213eab1e08 ("doc: convert printk-formats.txt to rst") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-10-12lib/vsprintf: Hash legacy clock addressesGeert Uytterhoeven
On platforms using the Common Clock Framework, "%pC" prints the clock's name. On legacy platforms, it prints the unhashed clock's address, potentially leaking sensitive information regarding the kernel layout in memory. Avoid this leak by printing the hashed address instead. To distinguish between clocks, a 32-bit unique identifier is as good as an actual pointer value. Fixes: ad67b74d2469d9b8 ("printk: hash addresses printed with %p") Link: http://lkml.kernel.org/r/20181011084249.4520-3-geert+renesas@glider.be To: "Tobin C . Harding" <me@tobin.cc> To: Andrew Morton <akpm@linux-foundation.org> To: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-06-05lib/vsprintf: Remove atomic-unsafe support for %pCrGeert Uytterhoeven
"%pCr" formats the current rate of a clock, and calls clk_get_rate(). The latter obtains a mutex, hence it must not be called from atomic context. Remove support for this rarely-used format, as vsprintf() (and e.g. printk()) must be callable from any context. Any remaining out-of-tree users will start seeing the clock's name printed instead of its rate. Reported-by: Jia-Ju Bai <baijiaju1990@gmail.com> Fixes: 900cca2944254edd ("lib/vsprintf: add %pC{,n,r} format specifiers for clocks") Link: http://lkml.kernel.org/r/1527845302-12159-5-git-send-email-geert+renesas@glider.be To: Jia-Ju Bai <baijiaju1990@gmail.com> To: Jonathan Corbet <corbet@lwn.net> To: Michael Turquette <mturquette@baylibre.com> To: Stephen Boyd <sboyd@kernel.org> To: Zhang Rui <rui.zhang@intel.com> To: Eduardo Valentin <edubezval@gmail.com> To: Eric Anholt <eric@anholt.net> To: Stefan Wahren <stefan.wahren@i2se.com> To: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linux-doc@vger.kernel.org Cc: linux-clk@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: linux-serial@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-renesas-soc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: stable@vger.kernel.org # 4.1+ Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-03-23Documentation: Mention why %p prints ptrvalJoel Stanley
When debugging recent kernels, people will see '(ptrval)' but there isn't much information as to what that means. Briefly describe why it's there. Signed-off-by: Joel Stanley <joel@jms.id.au> Acked-by: Tobin C. Harding <me@tobin.cc> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-02-01Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk Pull printk updates from Petr Mladek: - Add a console_msg_format command line option: The value "default" keeps the old "[time stamp] text\n" format. The value "syslog" allows to see the syslog-like "<log level>[timestamp] text" format. This feature was requested by people doing regression tests, for example, 0day robot. They want to have both filtered and full logs at hands. - Reduce the risk of softlockup: Pass the console owner in a busy loop. This is a new approach to the old problem. It was first proposed by Steven Rostedt on Kernel Summit 2017. It marks a context in which the console_lock owner calls console drivers and could not sleep. On the other side, printk() callers could detect this state and use a busy wait instead of a simple console_trylock(). Finally, the console_lock owner checks if there is a busy waiter at the end of the special context and eventually passes the console_lock to the waiter. The hand-off works surprisingly well and helps in many situations. Well, there is still a possibility of the softlockup, for example, when the flood of messages stops and the last owner still has too much to flush. There is increasing number of people having problems with printk-related softlockups. We might eventually need to get better solution. Anyway, this looks like a good start and promising direction. - Do not allow to schedule in console_unlock() called from printk(): This reverts an older controversial commit. The reschedule helped to avoid softlockups. But it also slowed down the console output. This patch is obsoleted by the new console waiter logic described above. In fact, the reschedule made the hand-off less effective. - Deprecate "%pf" and "%pF" format specifier: It was needed on ia64, ppc64 and parisc64 to dereference function descriptors and show the real function address. It is done transparently by "%ps" and "pS" format specifier now. Sergey Senozhatsky found that all the function descriptors were in a special elf section and could be easily detected. - Remove printk_symbol() API: It has been obsoleted by "%pS" format specifier, and this change helped to remove few continuous lines and a less intuitive old API. - Remove redundant memsets: Sergey removed unnecessary memset when processing printk.devkmsg command line option. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: (27 commits) printk: drop redundant devkmsg_log_str memsets printk: Never set console_may_schedule in console_trylock() printk: Hide console waiter logic into helpers printk: Add console owner and waiter logic to load balance console writes kallsyms: remove print_symbol() function checkpatch: add pF/pf deprecation warning symbol lookup: introduce dereference_symbol_descriptor() parisc64: Add .opd based function descriptor dereference powerpc64: Add .opd based function descriptor dereference ia64: Add .opd based function descriptor dereference sections: split dereference_function_descriptor() openrisc: Fix conflicting types for _exext and _stext lib: do not use print_symbol() irq debug: do not use print_symbol() sysfs: do not use print_symbol() drivers: do not use print_symbol() x86: do not use print_symbol() unicore32: do not use print_symbol() sh: do not use print_symbol() mn10300: do not use print_symbol() ...
2017-12-21doc: convert printk-formats.txt to rstTobin C. Harding
Documentation/printk-formats.txt is a candidate for conversion to ReStructuredText format. Some effort has already been made to do this conversion even thought the suffix is currently .txt Changes required to complete conversion - Move printk-formats.txt to core-api/printk-formats.rst - Add entry to Documentation/core-api/index.rst - Remove entry from Documentation/00-INDEX - Fix minor grammatical errors. - Order heading adornments as suggested by rst docs. - Use 'Passed by reference' uniformly. - Update pointer documentation around %px specifier. - Fix erroneous double backticks (to commas). - Remove extraneous double backticks (suggested by Jonathan Corbet). - Simplify documentation for kobject. Signed-off-by: Tobin C. Harding <me@tobin.cc> [jc: downcased "kernel"] Signed-off-by: Jonathan Corbet <corbet@lwn.net>