trace: Don't use __weak in header files

The commit that added a check for this to checkpatch says:

"Using weak declarations can have unintended link defects.  The __weak on
the declaration causes non-weak definitions to become weak."

In this case, when a PowerPC kernel is built with CONFIG_KPROBE_EVENT
but not CONFIG_UPROBE_EVENT, it generates the following warning:

WARNING: 1 bad relocations
c0000000014f2190 R_PPC64_ADDR64    uprobes_fetch_type_table

This is fixed by passing the fetch_table arrays to
traceprobe_parse_probe_arg() which also means that they can never be NULL.

Link: http://lkml.kernel.org/r/20150312165834.4482cb48@canb.auug.org.au

Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

4 files changed, 15 insertions, 24 deletions

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index d73f565b4e06..f34c3ad1b5f4 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -250,7 +250,7 @@ DEFINE_FETCH_symbol(string_size)
 #define fetch_file_offset_string_size   NULL
 
 /* Fetch type information table */
-const struct fetch_type kprobes_fetch_type_table[] = {
+static const struct fetch_type kprobes_fetch_type_table[] = {
         /* Special types */
         [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
                                         sizeof(u32), 1, "__data_loc char[]"),
@@ -760,7 +760,8 @@ static int create_trace_kprobe(int argc, char **argv)
 
                 /* Parse fetch argument */
                 ret = traceprobe_parse_probe_arg(arg, &tk->tp.size, parg,
-                                                is_return, true);
+                                                is_return, true,
+                                                kprobes_fetch_type_table);
                 if (ret) {
                         pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
                         goto error;
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index b983b2fd2ca1..1769a81da8a7 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -356,17 +356,14 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t,
 
 /* Recursive argument parser */
 static int parse_probe_arg(char *arg, const struct fetch_type *t,
-                     struct fetch_param *f, bool is_return, bool is_kprobe)
+                     struct fetch_param *f, bool is_return, bool is_kprobe,
+                     const struct fetch_type *ftbl)
 {
-        const struct fetch_type *ftbl;
         unsigned long param;
         long offset;
         char *tmp;
         int ret = 0;
 
-        ftbl = is_kprobe ? kprobes_fetch_type_table : uprobes_fetch_type_table;
-        BUG_ON(ftbl == NULL);
-
         switch (arg[0]) {
         case '$':
                 ret = parse_probe_vars(arg + 1, t, f, is_return, is_kprobe);
@@ -447,7 +444,7 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t,
                         dprm->fetch_size = get_fetch_size_function(t,
                                                         dprm->fetch, ftbl);
                         ret = parse_probe_arg(arg, t2, &dprm->orig, is_return,
-                                                        is_kprobe);
+                                                        is_kprobe, ftbl);
                         if (ret)
                                 kfree(dprm);
                         else {
@@ -505,15 +502,12 @@ static int __parse_bitfield_probe_arg(const char *bf,
 
 /* String length checking wrapper */
 int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
-                struct probe_arg *parg, bool is_return, bool is_kprobe)
+                struct probe_arg *parg, bool is_return, bool is_kprobe,
+                const struct fetch_type *ftbl)
 {
-        const struct fetch_type *ftbl;
         const char *t;
         int ret;
 
-        ftbl = is_kprobe ? kprobes_fetch_type_table : uprobes_fetch_type_table;
-        BUG_ON(ftbl == NULL);
-
         if (strlen(arg) > MAX_ARGSTR_LEN) {
                 pr_info("Argument is too long.: %s\n",  arg);
                 return -ENOSPC;
@@ -535,7 +529,8 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
         }
         parg->offset = *size;
         *size += parg->type->size;
-        ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return, is_kprobe);
+        ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return,
+                              is_kprobe, ftbl);
 
         if (ret >= 0 && t != NULL)
                 ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch);
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 4f815fbce16d..e30f6cce4af6 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -229,13 +229,6 @@ ASSIGN_FETCH_FUNC(file_offset, ftype),			\
 #define FETCH_TYPE_STRING       0
 #define FETCH_TYPE_STRSIZE      1
 
-/*
- * Fetch type information table.
- * It's declared as a weak symbol due to conditional compilation.
- */
-extern __weak const struct fetch_type kprobes_fetch_type_table[];
-extern __weak const struct fetch_type uprobes_fetch_type_table[];
-
 #ifdef CONFIG_KPROBE_EVENT
 struct symbol_cache;
 unsigned long update_symbol_cache(struct symbol_cache *sc);
@@ -333,7 +326,8 @@ find_event_file_link(struct trace_probe *tp, struct ftrace_event_file *file)
 }
 
 extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
-                   struct probe_arg *parg, bool is_return, bool is_kprobe);
+                   struct probe_arg *parg, bool is_return, bool is_kprobe,
+                   const struct fetch_type *ftbl);
 
 extern int traceprobe_conflict_field_name(const char *name,
                                struct probe_arg *args, int narg);
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 7dc1c8abecd6..74865465e0b7 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -196,7 +196,7 @@ DEFINE_FETCH_file_offset(string)
 DEFINE_FETCH_file_offset(string_size)
 
 /* Fetch type information table */
-const struct fetch_type uprobes_fetch_type_table[] = {
+static const struct fetch_type uprobes_fetch_type_table[] = {
         /* Special types */
         [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
                                         sizeof(u32), 1, "__data_loc char[]"),
@@ -535,7 +535,8 @@ static int create_trace_uprobe(int argc, char **argv)
 
                 /* Parse fetch argument */
                 ret = traceprobe_parse_probe_arg(arg, &tu->tp.size, parg,
-                                                 is_return, false);
+                                                 is_return, false,
+                                                 uprobes_fetch_type_table);
                 if (ret) {
                         pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
                         goto error;