From 47e4ec68716624642f7108535960835bae7eff13 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Tue, 14 Jul 2026 10:10:04 +0900 Subject: [PATCH] tracing/probes: Extend max length of argument string To support BTF argument parsing (such as accessing fields within nested structures via typecasting), the maximum argument string length needs to be extended. Extend MAX_ARGSTR_LEN from 63 to 255. Since MAX_ARGSTR_LEN was previously reused to format command heads in trace_*probe_match_command_head() functions, introduce a dedicated MAX_COMMON_HEAD_LEN (63) macro for matching command heads and switch these functions to use the new macro. Link: https://lore.kernel.org/all/178399140457.27810.11387684872148824707.stgit@devnote2/ Assisted-by: Antigravity:gemini-3.5-flash Signed-off-by: Masami Hiramatsu (Google) --- kernel/trace/trace_fprobe.c | 2 +- kernel/trace/trace_kprobe.c | 2 +- kernel/trace/trace_probe.h | 3 ++- kernel/trace/trace_uprobe.c | 2 +- .../selftests/ftrace/test.d/dynevent/fprobe_syntax_errors.tc | 2 +- .../selftests/ftrace/test.d/dynevent/tprobe_syntax_errors.tc | 2 +- .../selftests/ftrace/test.d/kprobe/kprobe_syntax_errors.tc | 2 +- 7 files changed, 8 insertions(+), 7 deletions(-) diff --git a/kernel/trace/trace_fprobe.c b/kernel/trace/trace_fprobe.c index 536781cd4c47..5638a90e61cc 100644 --- a/kernel/trace/trace_fprobe.c +++ b/kernel/trace/trace_fprobe.c @@ -238,7 +238,7 @@ static bool trace_fprobe_is_busy(struct dyn_event *ev) static bool trace_fprobe_match_command_head(struct trace_fprobe *tf, int argc, const char **argv) { - char buf[MAX_ARGSTR_LEN + 1]; + char buf[MAX_COMMON_HEAD_LEN + 1]; if (!argc) return true; diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index cfa807d8e760..cc24e992732c 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -149,7 +149,7 @@ static bool trace_kprobe_is_busy(struct dyn_event *ev) static bool trace_kprobe_match_command_head(struct trace_kprobe *tk, int argc, const char **argv) { - char buf[MAX_ARGSTR_LEN + 1]; + char buf[MAX_COMMON_HEAD_LEN + 1]; if (!argc) return true; diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index e64e323244a5..e6d427910c4f 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -32,7 +32,8 @@ #include "trace_output.h" #define MAX_TRACE_ARGS 128 -#define MAX_ARGSTR_LEN 63 +#define MAX_ARGSTR_LEN 255 +#define MAX_COMMON_HEAD_LEN 63 #define MAX_ARRAY_LEN 64 #define MAX_ARG_NAME_LEN 32 #define MAX_BTF_ARGS_LEN 128 diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index b2e264a4b96c..67bd8fd91e3e 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -281,7 +281,7 @@ static bool trace_uprobe_is_busy(struct dyn_event *ev) static bool trace_uprobe_match_command_head(struct trace_uprobe *tu, int argc, const char **argv) { - char buf[MAX_ARGSTR_LEN + 1]; + char buf[MAX_COMMON_HEAD_LEN + 1]; int len; if (!argc) diff --git a/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_syntax_errors.tc b/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_syntax_errors.tc index e9d7e6919c7f..984ab94df213 100644 --- a/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_syntax_errors.tc +++ b/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_syntax_errors.tc @@ -75,7 +75,7 @@ check_error 'f vfs_read ^arg123456789012345678901234567890=@11' # ARG_NAME_TOO_L check_error 'f vfs_read ^=@11' # NO_ARG_NAME check_error 'f vfs_read ^var.1=@11' # BAD_ARG_NAME check_error 'f vfs_read var1=@11 ^var1=@12' # USED_ARG_NAME -check_error 'f vfs_read ^+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(@1234))))))' # ARG_TOO_LONG +check_error 'f vfs_read ^+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(@1234))))))))))))))))))))))))))' # ARG_TOO_LONG check_error 'f vfs_read arg1=^' # NO_ARG_BODY diff --git a/tools/testing/selftests/ftrace/test.d/dynevent/tprobe_syntax_errors.tc b/tools/testing/selftests/ftrace/test.d/dynevent/tprobe_syntax_errors.tc index ffe8ffef4027..2d0905b2c8b7 100644 --- a/tools/testing/selftests/ftrace/test.d/dynevent/tprobe_syntax_errors.tc +++ b/tools/testing/selftests/ftrace/test.d/dynevent/tprobe_syntax_errors.tc @@ -61,7 +61,7 @@ check_error 't kfree ^arg123456789012345678901234567890=@11' # ARG_NAME_TOO_LOG check_error 't kfree ^=@11' # NO_ARG_NAME check_error 't kfree ^var.1=@11' # BAD_ARG_NAME check_error 't kfree var1=@11 ^var1=@12' # USED_ARG_NAME -check_error 't kfree ^+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(@1234))))))' # ARG_TOO_LONG +check_error 't kfree ^+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(@1234))))))))))))))))))))))))))' # ARG_TOO_LONG check_error 't kfree arg1=^' # NO_ARG_BODY diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_syntax_errors.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_syntax_errors.tc index 21ce8414459f..d28f63b7e8a9 100644 --- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_syntax_errors.tc +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_syntax_errors.tc @@ -71,7 +71,7 @@ check_error 'p vfs_read ^arg123456789012345678901234567890=@11' # ARG_NAME_TOO_L check_error 'p vfs_read ^=@11' # NO_ARG_NAME check_error 'p vfs_read ^var.1=@11' # BAD_ARG_NAME check_error 'p vfs_read var1=@11 ^var1=@12' # USED_ARG_NAME -check_error 'p vfs_read ^+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(@1234))))))' # ARG_TOO_LONG +check_error 'p vfs_read ^+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(+1234567(@1234))))))))))))))))))))))))))' # ARG_TOO_LONG check_error 'p vfs_read arg1=^' # NO_ARG_BODY # instruction boundary check is valid on x86 (at this moment)