tracing/kprobes: Move common functions to trace_probe.h

The __get_data_size() and store_trace_args() will be used by uprobes
too.  Move them to a common location.

Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

1 files changed, 48 insertions, 0 deletions

diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 984e91ed8a44..d384fbd4025c 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -178,3 +178,51 @@ extern ssize_t traceprobe_probes_write(struct file *file,
 		int (*createfn)(int, char**));
 
 extern int traceprobe_command(const char *buf, int (*createfn)(int, char**));
+
+/* Sum up total data length for dynamic arraies (strings) */
+static inline __kprobes int
+__get_data_size(struct trace_probe *tp, struct pt_regs *regs)
+{
+	int i, ret = 0;
+	u32 len;
+
+	for (i = 0; i < tp->nr_args; i++)
+		if (unlikely(tp->args[i].fetch_size.fn)) {
+			call_fetch(&tp->args[i].fetch_size, regs, &len);
+			ret += len;
+		}
+
+	return ret;
+}
+
+/* Store the value of each argument */
+static inline __kprobes void
+store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs,
+		 u8 *data, int maxlen)
+{
+	int i;
+	u32 end = tp->size;
+	u32 *dl;	/* Data (relative) location */
+
+	for (i = 0; i < tp->nr_args; i++) {
+		if (unlikely(tp->args[i].fetch_size.fn)) {
+			/*
+			 * First, we set the relative location and
+			 * maximum data length to *dl
+			 */
+			dl = (u32 *)(data + tp->args[i].offset);
+			*dl = make_data_rloc(maxlen, end - tp->args[i].offset);
+			/* Then try to fetch string or dynamic array data */
+			call_fetch(&tp->args[i].fetch, regs, dl);
+			/* Reduce maximum length */
+			end += get_rloc_len(*dl);
+			maxlen -= get_rloc_len(*dl);
+			/* Trick here, convert data_rloc to data_loc */
+			*dl = convert_rloc_to_loc(*dl,
+				 ent_size + tp->args[i].offset);
+		} else
+			/* Just fetching data normally */
+			call_fetch(&tp->args[i].fetch, regs,
+				   data + tp->args[i].offset);
+	}
+}