user/sven/linux.git/kernel/stacktrace.c, branch v5.4.270

stacktrace: Don't skip first entry on noncurrent tasks

2019-11-04T20:19:25Z

When doing cat /proc//stack, the output is missing the first entry. When the current code walks the stack starting in stack_trace_save_tsk, it skips all scheduler functions (that's OK) plus one more function. But this one function should be skipped only for the 'current' task as it is stack_trace_save_tsk proper. The original code (before the common infrastructure) skipped one function only for the 'current' task -- see save_stack_trace_tsk before 3599fe12a125. So do so also in the new infrastructure now. Fixes: 214d8ca6ee85 ("stacktrace: Provide common infrastructure") Signed-off-by: Jiri Slaby Signed-off-by: Thomas Gleixner Tested-by: Michal Suchanek Acked-by: Josh Poimboeuf Link: https://lkml.kernel.org/r/20191030072545.19462-1-jslaby@suse.cz

stacktrace: Constify 'entries' arguments

2019-07-25T13:43:26Z

Make it clear to humans and to the compiler that the stack trace ('entries') arguments are not modified. Signed-off-by: Bart Van Assche Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Waiman Long Cc: Will Deacon Link: https://lkml.kernel.org/r/20190722182443.216015-3-bvanassche@acm.org Signed-off-by: Ingo Molnar

stacktrace: Force USER_DS for stack_trace_save_user()

2019-07-18T14:47:24Z

When walking userspace stacks, USER_DS needs to be set, otherwise access_ok() will not function as expected. Reported-by: Vegard Nossum Reported-by: Eiichi Tsukata Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner Tested-by: Vegard Nossum Reviewed-by: Joel Fernandes (Google) Link: https://lkml.kernel.org/r/20190718085754.GM3402@hirez.programming.kicks-ass.net

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching

2019-07-11T22:30:05Z

Pull livepatching updates from Jiri Kosina: - stacktrace handling improvements from Miroslav benes - debug output improvements from Petr Mladek * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching: livepatch: Remove duplicate warning about missing reliable stacktrace support Revert "livepatch: Remove reliable stacktrace check in klp_try_switch_task()" stacktrace: Remove weak version of save_stack_trace_tsk_reliable() livepatch: Use static buffer for debugging messages under rq lock livepatch: Remove stale kobj_added entries from kernel-doc descriptions

stacktrace: Use PF_KTHREAD to check for kernel threads

2019-07-03T07:04:06Z

!current->mm is not a reliable indicator for kernel threads as they might temporarily use a user mm. Check for PF_KTHREAD instead. Signed-off-by: Thomas Gleixner Acked-by: Mark Rutland Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: Steven Rostedt Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1907021750100.1802@nanos.tec.linutronix.de

stacktrace: Remove weak version of save_stack_trace_tsk_reliable()

2019-06-20T13:43:31Z

Recent rework of stack trace infrastructure introduced a new set of helpers for common stack trace operations (commit e9b98e162aa5 ("stacktrace: Provide helpers for common stack trace operations") and related). As a result, save_stack_trace_tsk_reliable() is not directly called anywhere. Livepatch, currently the only user of the reliable stack trace feature, now calls stack_trace_save_tsk_reliable(). When CONFIG_HAVE_RELIABLE_STACKTRACE is set and depending on CONFIG_ARCH_STACKWALK, stack_trace_save_tsk_reliable() calls either arch_stack_walk_reliable() or mentioned save_stack_trace_tsk_reliable(). x86_64 defines the former, ppc64le the latter. All other architectures do not have HAVE_RELIABLE_STACKTRACE and include/linux/stacktrace.h defines -ENOSYS returning version for them. In short, stack_trace_save_tsk_reliable() returning -ENOSYS defined in include/linux/stacktrace.h serves the same purpose as the old weak version of save_stack_trace_tsk_reliable() which is therefore no longer needed. Signed-off-by: Miroslav Benes Acked-by: Josh Poimboeuf Reviewed-by: Thomas Gleixner Reviewed-by: Kamalesh Babulal Signed-off-by: Petr Mladek

Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2019-06-02T18:04:42Z

Pull stacktrace fix from Ingo Molnar: "Fix a stack_trace_save_tsk_reliable() regression" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: stacktrace: Unbreak stack_trace_save_tsk_reliable()

treewide: Add SPDX license identifier for missed files

2019-05-21T08:50:45Z

Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

stacktrace: Unbreak stack_trace_save_tsk_reliable()

2019-05-19T09:43:22Z

Miroslav reported that the livepatch self-tests were failing, specifically a case in which the consistency model ensures that a current executing function is not allowed to be patched, "TEST: busy target module". Recent renovations of stack_trace_save_tsk_reliable() left it returning only an -ERRNO success indication in some configuration combinations: klp_check_stack() ret = stack_trace_save_tsk_reliable() #ifdef CONFIG_ARCH_STACKWALK && CONFIG_HAVE_RELIABLE_STACKTRACE stack_trace_save_tsk_reliable() ret = arch_stack_walk_reliable() return 0 return -EINVAL ... return ret; ... if (ret < 0) /* stack_trace_save_tsk_reliable error */ nr_entries = ret; << 0 Previously (and currently for !CONFIG_ARCH_STACKWALK && CONFIG_HAVE_RELIABLE_STACKTRACE) stack_trace_save_tsk_reliable() returned the number of entries that it consumed in the passed storage array. In the case of the above config and trace, be sure to return the stacktrace_cookie.len on stack_trace_save_tsk_reliable() success. Fixes: 25e39e32b0a3f ("livepatch: Simplify stack trace retrieval") Reported-by: Miroslav Benes Signed-off-by: Joe Lawrence Signed-off-by: Thomas Gleixner Reviewed-by: Kamalesh Babulal Acked-by: Josh Poimboeuf Cc: live-patching@vger.kernel.org Cc: jikos@kernel.org Cc: pmladek@suse.com Link: https://lkml.kernel.org/r/20190517185117.24642-1-joe.lawrence@redhat.com

stacktrace: Provide common infrastructure

2019-04-29T10:37:57Z

All architectures which support stacktrace carry duplicated code and do the stack storage and filtering at the architecture side. Provide a consolidated interface with a callback function for consuming the stack entries provided by the architecture specific stack walker. This removes lots of duplicated code and allows to implement better filtering than 'skip number of entries' in the future without touching any architecture specific code. Signed-off-by: Thomas Gleixner Reviewed-by: Josh Poimboeuf Cc: Andy Lutomirski Cc: linux-arch@vger.kernel.org Cc: Steven Rostedt Cc: Alexander Potapenko Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Christoph Lameter Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: David Rientjes Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Cc: Akinobu Mita Cc: Christoph Hellwig Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Cc: Marek Szyprowski Cc: Johannes Thumshirn Cc: David Sterba Cc: Chris Mason Cc: Josef Bacik Cc: linux-btrfs@vger.kernel.org Cc: dm-devel@redhat.com Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tom Zanussi Cc: Miroslav Benes Link: https://lkml.kernel.org/r/20190425094803.713568606@linutronix.de