On Mon, 13 Jul 2026 00:06:42 +0900 "Masami Hiramatsu (Google)" <[email protected]> wrote:
> From: Masami Hiramatsu <[email protected]> > > 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 256. > > 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. > > Assisted-by: Antigravity:gemini-3.5-flash > Signed-off-by: Masami Hiramatsu (Google) <[email protected]> Sashiko asked to extend other macros, > Does this code also need to increase MAX_BTF_ARGS_LEN and MAX_DENTRY_ARGS_LEN? I don't agree this. MAX_BTF_ARGS_LEN is only for expanding "$args" into each parameter names. The other arguments are kept on the same memory. MAX_DENTRY_ARGS_LEN is already 256, so I think if that is too long, it should be rejected. (But MAX_ARGSTR_LEN should be 255.) BTW, both macro names are a bit complicated because those are just buffer size, not max length of something. Thank you, > --- > kernel/trace/trace_fprobe.c | 2 +- > kernel/trace/trace_kprobe.c | 2 +- > kernel/trace/trace_probe.h | 3 ++- > kernel/trace/trace_uprobe.c | 2 +- > .../ftrace/test.d/dynevent/fprobe_syntax_errors.tc | 2 +- > .../ftrace/test.d/dynevent/tprobe_syntax_errors.tc | 2 +- > .../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..e6aee800a7d9 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 256 > +#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) > -- Masami Hiramatsu (Google) <[email protected]>
