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Commit d9a16d3a authored by Stephen Rothwell's avatar Stephen Rothwell Committed by Steven Rostedt
Browse files

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: default avatarMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: default avatarStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 754cb007

kernel/trace/trace_kprobe.c

+3 −2
Original line number Diff line number Diff line
@@ -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;

kernel/trace/trace_probe.c

+7 −12
Original line number Diff line number Diff line
@@ -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);

kernel/trace/trace_probe.h

+2 −8
Original line number Diff line number Diff line
@@ -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);

kernel/trace/trace_uprobe.c

+3 −2
Original line number Diff line number Diff line
@@ -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;