kernel/trace: Provide default impelentations defined in trace_probe_tmpl.h

There are 6 function definitions in trace_probe_tmpl.h, they are:

1, fetch_store_strlen
2, fetch_store_string
3, fetch_store_strlen_user
4, fetch_store_string_user
5, probe_mem_read
6, probe_mem_read_user

Every C file which includes trace_probe_tmpl.h has to implement them,
otherwise it gets warnings and errors. However, some of them are identical,
like kprobe and eprobe, as a result, there is a lot redundant code in those
2 files.

This patch would like to provide default behaviors for those functions
which kprobe and eprobe can share by just including trace_probe_kernel.h
with trace_probe_tmpl.h together.

It removes redundant code, increases readability, and more importantly,
makes it easier to introduce a new feature based on trace probe
(it's possible).

Link: https://lore.kernel.org/all/1672382018-18347-1-git-send-email-chensong_2000@189.cn/

Signed-off-by: Song Chen <chensong_2000@189.cn>
Reported-by: kernel test robot <lkp@intel.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

1 files changed, 2 insertions, 53 deletions

diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index 9d0ebcffb539..846546395d62 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -320,7 +320,8 @@ print_eprobe_event(struct trace_iterator *iter, int flags,
 	return trace_handle_return(s);
 }
 
-static unsigned long get_event_field(struct fetch_insn *code, void *rec)
+static nokprobe_inline unsigned long
+get_event_field(struct fetch_insn *code, void *rec)
 {
 	struct ftrace_event_field *field = code->data;
 	unsigned long val;
@@ -454,58 +455,6 @@ process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
 }
 NOKPROBE_SYMBOL(process_fetch_insn)
 
-/* Return the length of string -- including null terminal byte */
-static nokprobe_inline int
-fetch_store_strlen_user(unsigned long addr)
-{
-	return kern_fetch_store_strlen_user(addr);
-}
-
-/* Return the length of string -- including null terminal byte */
-static nokprobe_inline int
-fetch_store_strlen(unsigned long addr)
-{
-	return kern_fetch_store_strlen(addr);
-}
-
-/*
- * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf
- * with max length and relative data location.
- */
-static nokprobe_inline int
-fetch_store_string_user(unsigned long addr, void *dest, void *base)
-{
-	return kern_fetch_store_string_user(addr, dest, base);
-}
-
-/*
- * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max
- * length and relative data location.
- */
-static nokprobe_inline int
-fetch_store_string(unsigned long addr, void *dest, void *base)
-{
-	return kern_fetch_store_string(addr, dest, base);
-}
-
-static nokprobe_inline int
-probe_mem_read_user(void *dest, void *src, size_t size)
-{
-	const void __user *uaddr =  (__force const void __user *)src;
-
-	return copy_from_user_nofault(dest, uaddr, size);
-}
-
-static nokprobe_inline int
-probe_mem_read(void *dest, void *src, size_t size)
-{
-#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
-	if ((unsigned long)src < TASK_SIZE)
-		return probe_mem_read_user(dest, src, size);
-#endif
-	return copy_from_kernel_nofault(dest, src, size);
-}
-
 /* eprobe handler */
 static inline void
 __eprobe_trace_func(struct eprobe_data *edata, void *rec)