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Linus Torvalds
b8a7a86e48
Pull ftrace updates from Steven Rostedt: - Have the stacktrace option work with func-args The func_stack_trace option has it's own ftrace handler and so does the func-args option. When they are both set, neither would run. The function tracer itself would error out. Allow the stacktrace and function args to work together. - Avoid BTF lookup in atomic context The ftrace_dump() can call function graph tracing output from an atomic context (like an NMI watchdog going off). The BTF lookup is not safe to call from atomic context. Have btf_find_func_proto() return if in atomic context. - Build trace_btf.c when CONFIG_DEBUG_INFO_BTF is enabled New code is depending on trace_btf.c but that only gets built when BPF_SYSCALL is also enabled. As the new code doesn't depend on that, have trace_btf.c get built with just DEBUG_INFO_BTF set. - Have function graph return values have BTF processing Have the return values printed by the function graph tracer use BTF to print the values in better format. For example, if it's a char, short, signed or unsigned, print according to the value defined by BTF. - Add a "max" field to the function profiler stats The function profiler shows all the functions run in the kernel, the number of times they are called, and the total time they took up. Also add a "max" field which holds the longest time a function ran for. - Fix memory leak in module with all skipped functions On module load, the ftrace entries are recorded to keep track of what functions can be traced or not. Some functions may be skipped for various reasons (some defined by the architecture). If all functions in the module are skipped, its data page is not freed and can leak. Catch this case and free the empty page. - Allow architectures to reject functions from being traced Allow architectures to skip a function address by returning zero from ftrace_call_adjust(). - Initialize modname and offset in print_rec() The variables modname and offset are initialized by kallsyms_lookup(). If that fails, the values are not set, but the code continues to print other information. The modname and offset are used later, but if the kallsyms_lookup() failed, they will not be set. If a module is being loaded and unloaded at the same time as reading the available_filter_functions file, it can cause a fault due to the lookup failing and modname and offset being used uninitialized. * tag 'trace-ftrace-v7.4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ftrace: Initialize modname and offset in print_rec() ftrace: Let ftrace_call_adjust() reject a patch site ftrace: Do not leak a module's empty page group ftrace: Add max field to function profiler stats tracing: Update funcgraph-retval documentation fgraph: Enhance funcgraph-retval with BTF-based type-aware output ftrace: Build trace_btf.c when CONFIG_DEBUG_INFO_BTF is enabled tracing: Avoid BTF lookup in atomic context ftrace: Have stacktrace option work with func-args