From 011ea0501daaba36c06910fd383cf7428ea45844 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Tue, 28 Oct 2025 19:11:20 -0400 Subject: tracing: Display some syscall arrays as strings Some of the system calls that read a fixed length of memory from the user space address are not arrays but strings. Take a bit away from the nb_args field in the syscall meta data to use as a flag to denote that the system call's user_arg_size is being used as a string. The nb_args should never be more than 6, so 7 bits is plenty to hold that number. When the user_arg_is_str flag that, when set, will display the data array from the user space address as a string and not an array. This will allow the output to look like this: sys_sethostname(name: 0x5584310eb2a0 "debian", len: 6) Cc: Masami Hiramatsu Cc: Mark Rutland Cc: Mathieu Desnoyers Cc: Andrew Morton Cc: Peter Zijlstra Cc: Namhyung Kim Cc: Takaya Saeki Cc: Tom Zanussi Cc: Thomas Gleixner Cc: Ian Rogers Cc: Douglas Raillard Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Adrian Hunter Cc: Ingo Molnar Link: https://lore.kernel.org/20251028231147.930550359@kernel.org Signed-off-by: Steven Rostedt (Google) --- include/trace/syscall.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'include/trace') diff --git a/include/trace/syscall.h b/include/trace/syscall.h index 9413c139da66..0dd7f2b33431 100644 --- a/include/trace/syscall.h +++ b/include/trace/syscall.h @@ -16,6 +16,7 @@ * @name: name of the syscall * @syscall_nr: number of the syscall * @nb_args: number of parameters it takes + * @user_arg_is_str: set if the arg for @user_arg_size is a string * @user_arg_size: holds @arg that has size of the user space to read * @user_mask: mask of @args that will read user space * @types: list of types as strings @@ -27,7 +28,8 @@ struct syscall_metadata { const char *name; int syscall_nr; - u8 nb_args; + u8 nb_args:7; + u8 user_arg_is_str:1; s8 user_arg_size; short user_mask; const char **types; -- cgit v1.2.3