[PATCH 0/5] tracing/probes: Clean up and refactor argument parser

["Masami Hiramatsu (Google)" <mhiramat@kernel.org>]

Hi,

This is the 2nd version of the series which refactors and cleans up
the fetcharg parser in the trace_probe. The previous version is here:

  https://lore.kernel.org/all/178386876526.3174487.5142283230157728964.stgit@devnote2/

The main goals are to improve code readability, prevent kernel stack
overflow by eliminating recursive function calls, and extend the
argument string length limit to support complex BTF typecast
expressions.

In this version, I fixed the double error log issue in [1/5], make
MAX_ARGSTR_LEN to 255 [4/5] and update patch description for clarify
this change updates the behavior (not a cleanup) and
make TRACEPROBE_MAX_NESTED_LEVEL to 8 (also update testcases)[5/5].

Patches:
- Patch 1: Decomposes parse_probe_vars() into smaller, dedicated helper 
  functions for parsing specific variable types ($retval, $stack, etc.).
- Patch 2: Decomposes parse_probe_arg() into static helper subroutines for 
  handling registers, memory/symbols, and immediates.
- Patch 3: Alphabetizes the ERRORS macros list in trace_probe.h to improve 
  readability.
- Patch 4: Extends MAX_ARGSTR_LEN from 63 to 255 for long BTF cast/dereference
  arguments, and introduces MAX_COMMON_HEAD_LEN to prevent regression on match
  head commands.
- Patch 5: Eliminates recursion in parse_probe_arg() using a loop and a parse 
  state stack integrated into traceprobe_parse_context. It also raises the
  nesting limit to 8 and updates the selftest scripts.

Thanks,

---

Masami Hiramatsu (5):
      tracing/probes: Refactor parse_probe_vars()
      tracing/probes: Refactor parse_probe_arg()
      tracing/probes: Sort ERRORS list in trace_probe.h alphabetically
      tracing/probes: Extend max length of argument string
      tracing/probes: Eliminate recursion in parse_probe_arg()


 kernel/trace/trace_fprobe.c                        |    2 
 kernel/trace/trace_kprobe.c                        |    2 
 kernel/trace/trace_probe.c                         |  829 ++++++++++++--------
 kernel/trace/trace_probe.h                         |  196 +++--
 kernel/trace/trace_uprobe.c                        |    2 
 .../ftrace/test.d/dynevent/fprobe_syntax_errors.tc |    6 
 .../ftrace/test.d/dynevent/tprobe_syntax_errors.tc |    4 
 .../ftrace/test.d/kprobe/kprobe_syntax_errors.tc   |    6 
 8 files changed, 621 insertions(+), 426 deletions(-)

--
Masami Hiramatsu (Google) <mhiramat@kernel.org>