[PATCH v7 07/10] tracing/probes: Have process_fetch_insn() take a void * instead of pt_regs

From: Steven Rostedt
Date: Thu Aug 19 2021 - 00:19:14 EST


From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>

In preparation to allow event probes to use the process_fetch_insn()
callback in trace_probe_tmpl.h, change the data passed to it from a
pointer to pt_regs, as the event probe will not be using regs, and make it
a void pointer instead.

Update the process_fetch_insn() callers for kprobe and uprobe events to
have the regs defined in the function and just typecast the void pointer
parameter.

Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
kernel/trace/trace_kprobe.c | 3 ++-
kernel/trace/trace_probe_tmpl.h | 6 +++---
kernel/trace/trace_uprobe.c | 3 ++-
3 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index c6fe7a6e3f35..4b013d24f5a9 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1325,9 +1325,10 @@ probe_mem_read(void *dest, void *src, size_t size)

/* Note that we don't verify it, since the code does not come from user space */
static int
-process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
+process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
void *base)
{
+ struct pt_regs *regs = rec;
unsigned long val;

retry:
diff --git a/kernel/trace/trace_probe_tmpl.h b/kernel/trace/trace_probe_tmpl.h
index f003c5d02a3a..b3bdb8ddb862 100644
--- a/kernel/trace/trace_probe_tmpl.h
+++ b/kernel/trace/trace_probe_tmpl.h
@@ -54,7 +54,7 @@ fetch_apply_bitfield(struct fetch_insn *code, void *buf)
* If dest is NULL, don't store result and return required dynamic data size.
*/
static int
-process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs,
+process_fetch_insn(struct fetch_insn *code, void *rec,
void *dest, void *base);
static nokprobe_inline int fetch_store_strlen(unsigned long addr);
static nokprobe_inline int
@@ -188,7 +188,7 @@ __get_data_size(struct trace_probe *tp, struct pt_regs *regs)

/* Store the value of each argument */
static nokprobe_inline void
-store_trace_args(void *data, struct trace_probe *tp, struct pt_regs *regs,
+store_trace_args(void *data, struct trace_probe *tp, void *rec,
int header_size, int maxlen)
{
struct probe_arg *arg;
@@ -203,7 +203,7 @@ store_trace_args(void *data, struct trace_probe *tp, struct pt_regs *regs,
/* Point the dynamic data area if needed */
if (unlikely(arg->dynamic))
*dl = make_data_loc(maxlen, dyndata - base);
- ret = process_fetch_insn(arg->code, regs, dl, base);
+ ret = process_fetch_insn(arg->code, rec, dl, base);
if (unlikely(ret < 0 && arg->dynamic)) {
*dl = make_data_loc(0, dyndata - base);
} else {
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 09f8ca7f7ba0..d219ba50efbd 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -213,9 +213,10 @@ static unsigned long translate_user_vaddr(unsigned long file_offset)

/* Note that we don't verify it, since the code does not come from user space */
static int
-process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
+process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
void *base)
{
+ struct pt_regs *regs = rec;
unsigned long val;

/* 1st stage: get value from context */
--
2.30.2