perf trace: Split BPF skel code to util/bpf_trace_augment.c

2025-06-26T17:31:05+00:00

And make builtin-trace.c less conditional. Dummy functions will be called when BUILD_BPF_SKEL=0 is used. This makes the builtin-trace.c slightly smaller and simpler by removing the skeleton and its helpers. The conditional guard of trace__init_syscalls_bpf_prog_array_maps() is changed from the HAVE_BPF_SKEL to HAVE_LIBBPF_SUPPORT as it doesn't have a skeleton in the code directly. And a dummy function is added so that it can be called unconditionally. The function will succeed only if the both conditions are true. Do not include trace_augment.h from the BPF code and move the definition of TRACE_AUG_MAX_BUF to the BPF directly. Reviewed-by: Howard Chu Tested-by: Arnaldo Carvalho de Melo Link: https://lore.kernel.org/r/20250623225721.21553-1-namhyung@kernel.org Signed-off-by: Namhyung Kim

perf trace: Pretty print buffer data

2024-09-10T12:52:13+00:00

Define TRACE_AUG_MAX_BUF in trace_augment.h data, which is the maximum buffer size we can augment. BPF will include this header too. Print buffer in a way that's different than just printing a string, we print all the control characters in \digits (such as \0 for null, and \10 for newline, LF). For character that has a bigger value than 127, we print the digits instead of the character itself as well. Committer notes: Simplified the buffer scnprintf to avoid using multiple buffers as discussed in the patch review thread. We can't really all 'buf' args to SCA_BUF as we're collecting so far just on the sys_enter path, so we would be printing the previous 'read' arg buffer contents, not what the kernel puts there. So instead of: static int syscall_fmt__cmp(const void *name, const void *fmtp) @@ -1987,8 +1989,6 @@ syscall_arg_fmt__init_array(struct syscall_arg_fmt *arg, struct tep_format_field - else if (strstr(field->type, "char *") && strstr(field->name, "buf")) - arg->scnprintf = SCA_BUF; Do: static const struct syscall_fmt syscall_fmts[] = { + { .name = "write", .errpid = true, + .arg = { [1] = { .scnprintf = SCA_BUF /* buf */, from_user = true, }, }, }, Signed-off-by: Howard Chu Cc: Adrian Hunter Cc: Ian Rogers Cc: Jiri Olsa Cc: Kan Liang Cc: Namhyung Kim Link: https://lore.kernel.org/r/20240815013626.935097-8-howardchu95@gmail.com Link: https://lore.kernel.org/r/20240824163322.60796-6-howardchu95@gmail.com Signed-off-by: Arnaldo Carvalho de Melo

kernel/linux.git/tools/perf/util/trace_augment.h, branch v6.18.21

perf trace: Split BPF skel code to util/bpf_trace_augment.c

perf trace: Pretty print buffer data