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>

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index d73f565b4e062127789bce243dc9c2e365dbb175..f34c3ad1b5f400fba475826021509503e68e68d3 100644 (file)
--- 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 b983b2fd2ca171343d188739d245f8579eade04c..1769a81da8a783a1331ca6163646c7229b747e61 100644 (file)
--- 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 4f815fbce16d26eefbc8e3b572ec9f2fdca7879b..e30f6cce4af67cbe5030d423c5854bf1d24bb1f5 100644 (file)
--- 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 7dc1c8abecd6c6fd831a3f952d67454261dc2ab9..74865465e0b71f8b1333fe636a2d49d63d97b84c 100644 (file)
--- 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;