linux.git - linus torvalds my love

Age	Commit message (Collapse)	Author
2025-12-17	unwind_user/fp: Use dummies instead of ifdef	Jens Remus
	This simplifies the code. unwind_user_next_fp() does not need to return -EINVAL if config option HAVE_UNWIND_USER_FP is disabled, as unwind_user_start() will then not select this unwind method and unwind_user_next() will therefore not call it. Provide (1) a dummy definition of ARCH_INIT_USER_FP_FRAME, if the unwind user method HAVE_UNWIND_USER_FP is not enabled, (2) a common fallback definition of unwind_user_at_function_start() which returns false, and (3) a common dummy definition of ARCH_INIT_USER_FP_ENTRY_FRAME. Note that enabling the config option HAVE_UNWIND_USER_FP without defining ARCH_INIT_USER_FP_FRAME triggers a compile error, which is helpful when implementing support for this unwind user method in an architecture. Enabling the config option when providing an arch- specific unwind_user_at_function_start() definition makes it necessary to also provide an arch-specific ARCH_INIT_USER_FP_ENTRY_FRAME definition. Signed-off-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20251208160352.1363040-3-jremus@linux.ibm.com
2025-07-29	unwind_user: Add user space unwinding API with frame pointer support	Josh Poimboeuf
	Introduce a generic API for unwinding user stacks. In order to expand user space unwinding to be able to handle more complex scenarios, such as deferred unwinding and reading user space information, create a generic interface that all architectures can use that support the various unwinding methods. This is an alternative method for handling user space stack traces from the simple stack_trace_save_user() API. This does not replace that interface, but this interface will be used to expand the functionality of user space stack walking. None of the structures introduced will be exposed to user space tooling. Support for frame pointer unwinding is added. For an architecture to support frame pointer unwinding it needs to enable CONFIG_HAVE_UNWIND_USER_FP and define ARCH_INIT_USER_FP_FRAME. By encoding the frame offsets in struct unwind_user_frame, much of this code can also be reused for future unwinder implementations like sframe. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Indu Bhagat <indu.bhagat@oracle.com> Cc: "Jose E. Marchesi" <jemarch@gnu.org> Cc: Beau Belgrave <beaub@linux.microsoft.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Florian Weimer <fweimer@redhat.com> Cc: Sam James <sam@gentoo.org> Link: https://lore.kernel.org/20250729182404.975790139@kernel.org Reviewed-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Co-developed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/all/20250710164301.3094-2-mathieu.desnoyers@efficios.com/ Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Co-developed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>