On Tue, 23 Jan 2024 17:21:35 +0800
Ye Bin <yebi...@huawei.com> wrote:
> Similar to '%pd' for printk, use '%pd' for print struct dentry's name.
>
> Signed-off-by: Ye Bin <yebi...@huawei.com>
> ---
> kernel/trace/trace_kprobe.c | 6 ++++++
> kernel/trace/trace_probe.h | 1 +
> 2 files changed, 7 insertions(+)
>
> diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
> index c4c6e0e0068b..00b74530fbad 100644
> --- a/kernel/trace/trace_kprobe.c
> +++ b/kernel/trace/trace_kprobe.c
> @@ -779,6 +779,7 @@ static int __trace_kprobe_create(int argc, const char
> *argv[])
> char buf[MAX_EVENT_NAME_LEN];
> char gbuf[MAX_EVENT_NAME_LEN];
> char abuf[MAX_BTF_ARGS_LEN];
> + char dbuf[MAX_DENTRY_ARGS_LEN];
Hmm, no, I don't like to expand stack anymore. Please allocate it
from heap.
> struct traceprobe_parse_context ctx = { .flags = TPARG_FL_KERNEL };
>
> switch (argv[0][0]) {
> @@ -930,6 +931,11 @@ static int __trace_kprobe_create(int argc, const char
> *argv[])
> argv = new_argv;
> }
>
> + ret = traceprobe_expand_dentry_args(argc, argv, dbuf,
> + MAX_DENTRY_ARGS_LEN);
> + if (ret)
> + goto out;
And calling this here will not cover the trace_fprobe.
Could you call this from traceprobe_expand_meta_args() instead of
calling it directly from trace_kprobe? Then it can be used from
fprobe_event too.
Thank you,
> +
> /* setup a probe */
> tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive,
> argc, is_return);
> diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
> index 553371a4e0b1..d9c053824975 100644
> --- a/kernel/trace/trace_probe.h
> +++ b/kernel/trace/trace_probe.h
> @@ -34,6 +34,7 @@
> #define MAX_ARRAY_LEN 64
> #define MAX_ARG_NAME_LEN 32
> #define MAX_BTF_ARGS_LEN 128
> +#define MAX_DENTRY_ARGS_LEN 256
Why do you think
> #define MAX_STRING_SIZE PATH_MAX
> #define MAX_ARG_BUF_LEN (MAX_TRACE_ARGS * MAX_ARG_NAME_LEN)
>
> --
> 2.31.1
>
>
--
Masami Hiramatsu (Google) <mhira...@kernel.org>
