[PATCH v3 2/7] tracing/probes: add traceprobe_expand_dentry_args() helper
From: Ye Bin <hidden>
Date: 2024-01-23 02:55:15
Also in:
lkml
Subsystem:
the rest, tracing · Maintainers:
Linus Torvalds, Steven Rostedt, Masami Hiramatsu
Add traceprobe_expand_dentry_args() to expand dentry args. this API is prepare to support "%pd" print format for kprobe. Signed-off-by: Ye Bin <redacted> --- kernel/trace/trace_probe.c | 36 ++++++++++++++++++++++++++++++++++++ kernel/trace/trace_probe.h | 2 ++ 2 files changed, 38 insertions(+)
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 4dc74d73fc1d..cc8bd7ea5341 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c@@ -1565,6 +1565,42 @@ const char **traceprobe_expand_meta_args(int argc, const char *argv[], return ERR_PTR(ret); } +int traceprobe_expand_dentry_args(int argc, const char *argv[], char *buf, + int bufsize) +{ + int i, used, ret; + + used = 0; + for (i = 0; i < argc; i++) { + size_t idx; + + if (str_has_suffix(argv[i], ":%pd", &idx)) { + char *tmp = kstrdup(argv[i], GFP_KERNEL); + char *equal; + + if (!tmp) + return -ENOMEM; + + equal = strchr(tmp, '='); + if (equal) + *equal = '\0'; + tmp[idx] = '\0'; + ret = snprintf(buf + used, bufsize - used, + "%s%s+0x0(+0x%zx(%s)):string", + equal ? tmp : "", equal ? "=" : "", + offsetof(struct dentry, d_name.name), + equal ? equal + 1 : tmp); + kfree(tmp); + if (ret >= bufsize - used) + return -ENOMEM; + argv[i] = buf + used; + used += ret + 1; + } + } + + return 0; +} + void traceprobe_finish_parse(struct traceprobe_parse_context *ctx) { clear_btf_context(ctx);
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 850d9ecb6765..553371a4e0b1 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h@@ -402,6 +402,8 @@ extern int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, const char **traceprobe_expand_meta_args(int argc, const char *argv[], int *new_argc, char *buf, int bufsize, struct traceprobe_parse_context *ctx); +extern int traceprobe_expand_dentry_args(int argc, const char *argv[], char *buf, + int bufsize); extern int traceprobe_update_arg(struct probe_arg *arg); extern void traceprobe_free_probe_arg(struct probe_arg *arg);
--
2.31.1