user/sven/linux.git/kernel/stacktrace.c, branch v5.10.245

stacktrace: Remove reliable argument from arch_stack_walk() callback

2020-09-18T13:24:16Z

Currently the callback passed to arch_stack_walk() has an argument called reliable passed to it to indicate if the stack entry is reliable, a comment says that this is used by some printk() consumers. However in the current kernel none of the arch_stack_walk() implementations ever set this flag to true and the only callback implementation we have is in the generic stacktrace code which ignores the flag. It therefore appears that this flag is redundant so we can simplify and clarify things by removing it. Signed-off-by: Mark Brown Reviewed-by: Miroslav Benes Link: https://lore.kernel.org/r/20200914153409.25097-2-broonie@kernel.org Signed-off-by: Will Deacon

uaccess: add force_uaccess_{begin,end} helpers

2020-08-12T17:57:59Z

Add helpers to wrap the get_fs/set_fs magic for undoing any damange done by set_fs(KERNEL_DS). There is no real functional benefit, but this documents the intent of these calls better, and will allow stubbing the functions out easily for kernels builds that do not allow address space overrides in the future. [hch@lst.de: drop two incorrect hunks, fix a commit log typo] Link: http://lkml.kernel.org/r/20200714105505.935079-6-hch@lst.de Signed-off-by: Christoph Hellwig Signed-off-by: Andrew Morton Acked-by: Linus Torvalds Acked-by: Mark Rutland Acked-by: Greentime Hu Acked-by: Geert Uytterhoeven Cc: Nick Hu Cc: Vincent Chen Cc: Paul Walmsley Cc: Palmer Dabbelt Link: http://lkml.kernel.org/r/20200710135706.537715-6-hch@lst.de Signed-off-by: Linus Torvalds

stacktrace: Get rid of unneeded '!!' pattern

2019-11-11T09:30:59Z

My commit b0c51f158455 ("stacktrace: Don't skip first entry on noncurrent tasks") adds one or zero to skipnr by "!!(current == tsk)". But the C99 standard says: The == (equal to) and != (not equal to) operators are ... Each of the operators yields 1 if the specified relation is true and 0 if it is false. So there is no need to prepend the above expression by "!!" -- remove it. Reported-by: Joe Perches Signed-off-by: Jiri Slaby Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: https://lkml.kernel.org/r/20191111092647.27419-1-jslaby@suse.cz Signed-off-by: Ingo Molnar

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()