user/sven/linux.git/kernel/trace/Kconfig, branch v6.16.2

ftrace: Have tracing function args depend on PROBE_EVENTS_BTF_ARGS

2025-04-02T13:50:56Z

The option PROBE_EVENTS_BTF_ARGS enables the functions btf_find_func_proto() and btf_get_func_param() which are used by the function argument tracing code. The option FUNCTION_TRACE_ARGS was dependent on the same configs that PROBE_EVENTS_BTF_ARGS was dependent on, but it was also dependent on PROBE_EVENTS_BTF_ARGS. In fact, if PROBE_EVENTS_BTF_ARGS is supported then FUNCTION_TRACE_ARGS is supported. Just make FUNCTION_TRACE_ARGS depend on PROBE_EVENTS_BTF_ARGS. Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Cc: Mark Rutland Link: https://lore.kernel.org/20250401113601.17fa1129@gandalf.local.home Fixes: 533c20b062d7c ("ftrace: Add print_function_args()") Closes: https://lore.kernel.org/all/DB9PR08MB75820599801BAD118D123D7D93AD2@DB9PR08MB7582.eurprd08.prod.outlook.com/ Reported-by: Christian Loehle Tested-by: Christian Loehle Tested-by: Leon Romanovsky Signed-off-by: Steven Rostedt (Google)

ftrace: Add support for function argument to graph tracer

2025-03-04T16:27:23Z

Wire up the code to print function arguments in the function graph tracer. This functionality can be enabled/disabled during runtime with options/funcgraph-args. Example usage: 6) | dummy_xmit [dummy](skb = 0x8887c100, dev = 0x872ca000) { 6) | consume_skb(skb = 0x8887c100) { 6) | skb_release_head_state(skb = 0x8887c100) { 6) 0.178 us | sock_wfree(skb = 0x8887c100) 6) 0.627 us | } Cc: Mark Rutland Cc: Mathieu Desnoyers Cc: Andrew Morton Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Guo Ren Cc: Donglin Peng Cc: Zheng Yejian Link: https://lore.kernel.org/20250227185822.810321199@goodmis.org Reviewed-by: Masami Hiramatsu (Google) Co-developed-by: Steven Rostedt (Google) Signed-off-by: Sven Schnelle Signed-off-by: Steven Rostedt (Google)

ftrace: Add print_function_args()

2025-03-04T16:27:23Z

Add a function to decode argument types with the help of BTF. Will be used to display arguments in the function and function graph tracer. It can only handle simply arguments and up to FTRACE_REGS_MAX_ARGS number of arguments. When it hits a max, it will print ", ...": page_to_skb(vi=0xffff8d53842dc980, rq=0xffff8d53843a0800, page=0xfffffc2e04337c00, offset=6160, len=64, truesize=1536, ...) And if it hits an argument that is not recognized, it will print the raw value and the type of argument it is: make_vfsuid(idmap=0xffffffff87f99db8, fs_userns=0xffffffff87e543c0, kuid=0x0 (STRUCT)) __pti_set_user_pgtbl(pgdp=0xffff8d5384ab47f8, pgd=0x110e74067 (STRUCT)) Cc: Mark Rutland Cc: Mathieu Desnoyers Cc: Andrew Morton Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Guo Ren Cc: Donglin Peng Cc: Zheng Yejian Link: https://lore.kernel.org/20250227185822.639418500@goodmis.org Reviewed-by: Masami Hiramatsu (Google) Co-developed-by: Steven Rostedt (Google) Signed-off-by: Sven Schnelle Signed-off-by: Steven Rostedt (Google)

fprobe: Rewrite fprobe on function-graph tracer

2024-12-26T15:50:05Z

Rewrite fprobe implementation on function-graph tracer. Major API changes are: - 'nr_maxactive' field is deprecated. - This depends on CONFIG_DYNAMIC_FTRACE_WITH_ARGS or !CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS, and CONFIG_HAVE_FUNCTION_GRAPH_FREGS. So currently works only on x86_64. - Currently the entry size is limited in 15 * sizeof(long). - If there is too many fprobe exit handler set on the same function, it will fail to probe. Signed-off-by: Masami Hiramatsu (Google) Acked-by: Heiko Carstens # s390 Cc: Alexei Starovoitov Cc: Florent Revest Cc: Martin KaFai Lau Cc: bpf Cc: Alexei Starovoitov Cc: Jiri Olsa Cc: Alan Maguire Cc: Heiko Carstens Cc: Mark Rutland Cc: Catalin Marinas Cc: Will Deacon Cc: Huacai Chen Cc: WANG Xuerui Cc: Michael Ellerman Cc: Nicholas Piggin Cc: Christophe Leroy Cc: Naveen N Rao Cc: Madhavan Srinivasan Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Vasily Gorbik Cc: Alexander Gordeev Cc: Christian Borntraeger Cc: Sven Schnelle Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Cc: x86@kernel.org Cc: "H. Peter Anvin" Cc: Mathieu Desnoyers Cc: Andrew Morton Link: https://lore.kernel.org/173519003970.391279.14406792285453830996.stgit@devnote2 Signed-off-by: Steven Rostedt (Google)

ftrace: Add CONFIG_HAVE_FTRACE_GRAPH_FUNC

2024-12-26T15:50:04Z

Add CONFIG_HAVE_FTRACE_GRAPH_FUNC kconfig in addition to ftrace_graph_func macro check. This is for the other feature (e.g. FPROBE) which requires to access ftrace_regs from fgraph_ops::entryfunc() can avoid compiling if the fgraph can not pass the valid ftrace_regs. Signed-off-by: Masami Hiramatsu (Google) Cc: Catalin Marinas Cc: Alexei Starovoitov Cc: Florent Revest Cc: Martin KaFai Lau Cc: bpf Cc: Alexei Starovoitov Cc: Jiri Olsa Cc: Alan Maguire Cc: Mark Rutland Cc: Will Deacon Cc: Huacai Chen Cc: WANG Xuerui Cc: Michael Ellerman Cc: Nicholas Piggin Cc: Christophe Leroy Cc: Naveen N Rao Cc: Madhavan Srinivasan Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Cc: x86@kernel.org Cc: "H. Peter Anvin" Cc: Mathieu Desnoyers Link: https://lore.kernel.org/173519001472.391279.1174901685282588467.stgit@devnote2 Signed-off-by: Steven Rostedt (Google)

tracing/fprobe: Enable fprobe events with CONFIG_DYNAMIC_FTRACE_WITH_ARGS

2024-12-26T15:50:04Z

Allow fprobe events to be enabled with CONFIG_DYNAMIC_FTRACE_WITH_ARGS. With this change, fprobe events mostly use ftrace_regs instead of pt_regs. Note that if the arch doesn't enable HAVE_FTRACE_REGS_HAVING_PT_REGS, fprobe events will not be able to be used from perf. Cc: Alexei Starovoitov Cc: Florent Revest Cc: Martin KaFai Lau Cc: bpf Cc: Alexei Starovoitov Cc: Jiri Olsa Cc: Alan Maguire Cc: Mark Rutland Link: https://lore.kernel.org/173518999352.391279.13332699755290175168.stgit@devnote2 Signed-off-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google)

fprobe: Use ftrace_regs in fprobe exit handler

2024-12-26T15:50:03Z

Change the fprobe exit handler to use ftrace_regs structure instead of pt_regs. This also introduce HAVE_FTRACE_REGS_HAVING_PT_REGS which means the ftrace_regs is including the pt_regs so that ftrace_regs can provide pt_regs without memory allocation. Fprobe introduces a new dependency with that. Signed-off-by: Masami Hiramatsu (Google) Acked-by: Heiko Carstens # s390 Cc: Huacai Chen Cc: Alexei Starovoitov Cc: Florent Revest Cc: bpf Cc: Alan Maguire Cc: Heiko Carstens Cc: WANG Xuerui Cc: Vasily Gorbik Cc: Alexander Gordeev Cc: Christian Borntraeger Cc: Sven Schnelle Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Cc: x86@kernel.org Cc: "H. Peter Anvin" Cc: Mark Rutland Cc: Mathieu Desnoyers Cc: Song Liu Cc: Jiri Olsa Cc: KP Singh Cc: Matt Bobrowski Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: Andrii Nakryiko Cc: Martin KaFai Lau Cc: Eduard Zingerman Cc: Yonghong Song Cc: John Fastabend Cc: Stanislav Fomichev Cc: Hao Luo Cc: Andrew Morton Link: https://lore.kernel.org/173518995092.391279.6765116450352977627.stgit@devnote2 Signed-off-by: Steven Rostedt (Google)

fprobe: Use ftrace_regs in fprobe entry handler

2024-12-26T15:50:03Z

This allows fprobes to be available with CONFIG_DYNAMIC_FTRACE_WITH_ARGS instead of CONFIG_DYNAMIC_FTRACE_WITH_REGS, then we can enable fprobe on arm64. Cc: Alexei Starovoitov Cc: Martin KaFai Lau Cc: bpf Cc: Alexei Starovoitov Cc: Jiri Olsa Cc: Alan Maguire Cc: Mark Rutland Link: https://lore.kernel.org/173518994037.391279.2786805566359674586.stgit@devnote2 Signed-off-by: Masami Hiramatsu (Google) Acked-by: Florent Revest Signed-off-by: Steven Rostedt (Google)

fgraph: Replace fgraph_ret_regs with ftrace_regs

2024-12-26T15:50:02Z

Use ftrace_regs instead of fgraph_ret_regs for tracing return value on function_graph tracer because of simplifying the callback interface. The CONFIG_HAVE_FUNCTION_GRAPH_RETVAL is also replaced by CONFIG_HAVE_FUNCTION_GRAPH_FREGS. Signed-off-by: Masami Hiramatsu (Google) Acked-by: Heiko Carstens Acked-by: Will Deacon Cc: Catalin Marinas Cc: Alexei Starovoitov Cc: Florent Revest Cc: Martin KaFai Lau Cc: bpf Cc: Alexei Starovoitov Cc: Jiri Olsa Cc: Alan Maguire Cc: Mark Rutland Cc: Huacai Chen Cc: WANG Xuerui Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Vasily Gorbik Cc: Alexander Gordeev Cc: Heiko Carstens Cc: Christian Borntraeger Cc: Sven Schnelle Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Cc: x86@kernel.org Cc: "H. Peter Anvin" Cc: Mathieu Desnoyers Link: https://lore.kernel.org/173518991508.391279.16635322774382197642.stgit@devnote2 Signed-off-by: Steven Rostedt (Google)

function_graph: Support recording and printing the function return address

2024-10-05T14:14:04Z

When using function_graph tracer to analyze the flow of kernel function execution, it is often necessary to quickly locate the exact line of code where the call occurs. While this may be easy at times, it can be more time-consuming when some functions are inlined or the flow is too long. This feature aims to simplify the process by recording the return address of traced funcions and printing it when outputing trace logs. To enhance human readability, the prefix 'ret=' is used for the kernel return value, while '<-' serves as the prefix for the return address in trace logs to make it look more like the function tracer. A new trace option named 'funcgraph-retaddr' has been introduced, and the existing option 'sym-addr' can be used to control the format of the return address. See below logs with both funcgraph-retval and funcgraph-retaddr enabled. 0) | load_elf_binary() { /* <-bprm_execve+0x249/0x600 */ 0) | load_elf_phdrs() { /* <-load_elf_binary+0x84/0x1730 */ 0) | __kmalloc_noprof() { /* <-load_elf_phdrs+0x4a/0xb0 */ 0) 3.657 us | __cond_resched(); /* <-__kmalloc_noprof+0x28c/0x390 ret=0x0 */ 0) + 24.335 us | } /* __kmalloc_noprof ret=0xffff8882007f3000 */ 0) | kernel_read() { /* <-load_elf_phdrs+0x6c/0xb0 */ 0) | rw_verify_area() { /* <-kernel_read+0x2b/0x50 */ 0) | security_file_permission() { /* <-kernel_read+0x2b/0x50 */ 0) | selinux_file_permission() { /* <-security_file_permission+0x26/0x40 */ 0) | __inode_security_revalidate() { /* <-selinux_file_permission+0x6d/0x140 */ 0) 2.034 us | __cond_resched(); /* <-__inode_security_revalidate+0x5f/0x80 ret=0x0 */ 0) 6.602 us | } /* __inode_security_revalidate ret=0x0 */ 0) 2.214 us | avc_policy_seqno(); /* <-selinux_file_permission+0x107/0x140 ret=0x0 */ 0) + 16.670 us | } /* selinux_file_permission ret=0x0 */ 0) + 20.809 us | } /* security_file_permission ret=0x0 */ 0) + 25.217 us | } /* rw_verify_area ret=0x0 */ 0) | __kernel_read() { /* <-load_elf_phdrs+0x6c/0xb0 */ 0) | ext4_file_read_iter() { /* <-__kernel_read+0x160/0x2e0 */ Then, we can use the faddr2line to locate the source code, for example: $ ./scripts/faddr2line ./vmlinux load_elf_phdrs+0x6c/0xb0 load_elf_phdrs+0x6c/0xb0: elf_read at fs/binfmt_elf.c:471 (inlined by) load_elf_phdrs at fs/binfmt_elf.c:531 Link: https://lore.kernel.org/20240915032912.1118397-1-dolinux.peng@gmail.com Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202409150605.HgUmU8ea-lkp@intel.com/ Signed-off-by: Donglin Peng [ Rebased to handle text_delta offsets ] Signed-off-by: Steven Rostedt (Google)