kernel/linux.git/include/linux/debugobjects.h, branch v6.19.11

debugobjects: Prepare for batching

2024-10-15T15:30:32+00:00

Move the debug_obj::object pointer into a union and add a pointer to the last node in a batch. That allows to implement batch processing efficiently by utilizing the stack property of hlist: When the first object of a batch is added to the list, then the batch pointer is set to the hlist node of the object itself. Any subsequent add retrieves the pointer to the last node from the first object in the list and uses that for storing the last node pointer in the newly added object. Add the pointer to the data structure and ensure that all relevant pool sizes are strictly batch sized. The actual batching implementation follows in subsequent changes. Signed-off-by: Thomas Gleixner Reviewed-by: Zhen Lei Link: https://lore.kernel.org/all/20241007164914.139204961@linutronix.de

lib: fix spelling mistakes in header files

2021-07-08T18:48:20+00:00

Fix some spelling mistakes in comments found by "codespell": Hoever ==> However poiter ==> pointer representaion ==> representation uppon ==> upon independend ==> independent aquired ==> acquired mis-match ==> mismatch scrach ==> scratch struture ==> structure Analagous ==> Analogous interation ==> iteration And some were discovered manually by Joe Perches and Christoph Lameter: stroed ==> stored arch independent ==> an architecture independent A example structure for ==> Example structure for Link: https://lkml.kernel.org/r/20210609150027.14805-2-thunder.leizhen@huawei.com Signed-off-by: Zhen Lei Cc: Christoph Lameter Cc: Masami Hiramatsu Cc: Dennis Zhou Cc: Tejun Heo Cc: Joe Perches Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

debugobjects: Allow debug_obj_descr to be const

2020-09-24T19:56:24+00:00

The debugobject core could be slightly harder to corrupt if the debug_obj_descr would be a pointer to const memory. Depending on the architecture, const data structures are placed into read-only memory and thus are harder to corrupt or hijack. This descriptor is used to fix up stuff like timers and workqueues when core kernel data structures are busted, so moving the descriptors to read-only memory will make debugobjects more resilient to something going wrong and then corrupting the function pointers inside struct debug_obj_descr. Signed-off-by: Stephen Boyd Signed-off-by: Thomas Gleixner Reviewed-by: Kees Cook Link: https://lore.kernel.org/r/20200815004027.2046113-2-swboyd@chromium.org

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55+00:00

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

debugobjects.h: fix trivial kernel doc warning

2016-07-26T23:19:19+00:00

Add ':' to fix trivial kernel-doc warning in : ..//include/linux/debugobjects.h:63: warning: No description found for parameter 'is_static_object' Link: http://lkml.kernel.org/r/575B01B8.5060600@infradead.org Signed-off-by: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

debugobjects: insulate non-fixup logic related to static obj from fixup callbacks

2016-05-20T02:12:14+00:00

When activating a static object we need make sure that the object is tracked in the object tracker. If it is a non-static object then the activation is illegal. In previous implementation, each subsystem need take care of this in their fixup callbacks. Actually we can put it into debugobjects core. Thus we can save duplicated code, and have *pure* fixup callbacks. To achieve this, a new callback "is_static_object" is introduced to let the type specific code decide whether a object is static or not. If yes, we take it into object tracker, otherwise give warning and invoke fixup callback. This change has paassed debugobjects selftest, and I also do some test with all debugobjects supports enabled. At last, I have a concern about the fixups that can it change the object which is in incorrect state on fixup? Because the 'addr' may not point to any valid object if a non-static object is not tracked. Then Change such object can overwrite someone's memory and cause unexpected behaviour. For example, the timer_fixup_activate bind timer to function stub_timer. Link: http://lkml.kernel.org/r/1462576157-14539-1-git-send-email-changbin.du@intel.com [changbin.du@intel.com: improve code comments where invoke the new is_static_object callback] Link: http://lkml.kernel.org/r/1462777431-8171-1-git-send-email-changbin.du@intel.com Signed-off-by: Du, Changbin Cc: Jonathan Corbet Cc: Josh Triplett Cc: Steven Rostedt Cc: Thomas Gleixner Cc: Tejun Heo Cc: Christian Borntraeger Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

debugobjects: make fixup functions return bool instead of int

2016-05-20T02:12:14+00:00

I am going to introduce debugobjects infrastructure to USB subsystem. But before this, I found the code of debugobjects could be improved. This patchset will make fixup functions return bool type instead of int. Because fixup only need report success or no. boolean is the 'real' type. This patch (of 7): The object debugging infrastructure core provides some fixup callbacks for the subsystem who use it. These callbacks are called from the debug code whenever a problem in debug_object_init is detected. And debugobjects core suppose them returns 1 when the fixup was successful, otherwise 0. So the return type is boolean. A bad thing is that debug_object_fixup use the return value for arithmetic operation. It confused me that what is the reall return type. Reading over the whole code, I found some place do use the return value incorrectly(see next patch). So why use bool type instead? Signed-off-by: Du, Changbin Cc: Jonathan Corbet Cc: Josh Triplett Cc: Steven Rostedt Cc: Thomas Gleixner Cc: Tejun Heo Cc: Christian Borntraeger Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

debugobjects: Make debug_object_activate() return status

2013-08-19T00:39:55+00:00

In order to better respond to things like duplicate invocations of call_rcu(), RCU needs to see the status of a call to debug_object_activate(). This would allow RCU to leak the callback in order to avoid adding freelist-reuse mischief to the duplicate invoations. This commit therefore makes debug_object_activate() return status, zero for success and -EINVAL for failure. Signed-off-by: Paul E. McKenney Cc: Mathieu Desnoyers Cc: Sedat Dilek Cc: Davidlohr Bueso Cc: Rik van Riel Cc: Thomas Gleixner Cc: Linus Torvalds Tested-by: Sedat Dilek Reviewed-by: Josh Triplett

debugobjects: Extend to assert that an object is initialized

2011-11-23T17:49:22+00:00

Calling del_timer_sync() on an uninitialized timer leads to a never ending loop in lock_timer_base() that spins checking for a non-NULL timer base. Add an assertion to debugobjects to catch usage of uninitialized objects so that we can initialize timers in the del_timer_sync() path before it calls lock_timer_base(). [ sboyd@codeaurora.org: Clarify commit message ] Signed-off-by: Christine Chan Signed-off-by: Stephen Boyd Cc: John Stultz Link: http://lkml.kernel.org/r/1320724108-20788-3-git-send-email-sboyd@codeaurora.org Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner

debugobjects: Add hint for better object identification

2011-03-08T15:10:38+00:00

In complex subsystems like mac80211 structures can contain several timers and work structs, so identifying a specific instance from the call trace and object type output of debugobjects can be hard. Allow the subsystems which support debugobjects to provide a hint function. This function returns a pointer to a kernel address (preferrably the objects callback function) which is printed along with the debugobjects type. Add hint methods for timer_list, work_struct and hrtimer. [ tglx: Massaged changelog, made it compile ] Signed-off-by: Stanislaw Gruszka LKML-Reference: <20110307085809.GA9334@redhat.com> Signed-off-by: Thomas Gleixner