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Commit 2fba0c88 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Frederic Weisbecker
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tracing/kprobes: Fix probe offset to be unsigned 



Prohibit user to specify negative offset from symbols.
Since kprobe.offset is unsigned int, the offset must be always positive
value.

Signed-off-by: default avatarMasami Hiramatsu <mhiramat@redhat.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <20090910235314.22412.64631.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
parent ad5cafcd

Documentation/trace/kprobetrace.txt

+7 −7
Original line number Diff line number Diff line
@@ -25,12 +25,12 @@ probe events via /sys/kernel/debug/tracing/events/kprobes/<EVENT>/filter. 


Synopsis of kprobe_events

-------------------------

  p[:EVENT] SYMBOL[+offs|-offs]|MEMADDR [FETCHARGS]	: Set a probe

  p[:EVENT] SYMBOL[+offs]|MEMADDR [FETCHARGS]	: Set a probe

  r[:EVENT] SYMBOL[+0] [FETCHARGS]		: Set a return probe



 EVENT		: Event name. If omitted, the event name is generated

		  based on SYMBOL+offs or MEMADDR.

 SYMBOL[+offs|-offs]	: Symbol+offset where the probe is inserted.

 SYMBOL[+offs]	: Symbol+offset where the probe is inserted.

 MEMADDR	: Address where the probe is inserted.



 FETCHARGS	: Arguments. Each probe can have up to 128 args.

kernel/trace/trace_kprobe.c

+7 −12
Original line number Diff line number Diff line
@@ -210,7 +210,7 @@ static __kprobes const char *probe_symbol(struct trace_probe *tp) 
	return tp->symbol ? tp->symbol : "unknown";

}



static __kprobes long probe_offset(struct trace_probe *tp)

static __kprobes unsigned int probe_offset(struct trace_probe *tp)

{

	return (probe_is_return(tp)) ? tp->rp.kp.offset : tp->kp.offset;

}
@@ -380,7 +380,7 @@ static int register_trace_probe(struct trace_probe *tp) 
}



/* Split symbol and offset. */

static int split_symbol_offset(char *symbol, long *offset)

static int split_symbol_offset(char *symbol, unsigned long *offset)

{

	char *tmp;

	int ret;
@@ -389,16 +389,11 @@ static int split_symbol_offset(char *symbol, long *offset) 
		return -EINVAL;



	tmp = strchr(symbol, '+');

	if (!tmp)

		tmp = strchr(symbol, '-');



	if (tmp) {

		/* skip sign because strict_strtol doesn't accept '+' */

		ret = strict_strtol(tmp + 1, 0, offset);

		ret = strict_strtoul(tmp + 1, 0, offset);

		if (ret)

			return ret;

		if (*tmp == '-')

			*offset = -(*offset);

		*tmp = '\0';

	} else

		*offset = 0;
@@ -520,7 +515,7 @@ static int create_trace_probe(int argc, char **argv) 
{

	/*

	 * Argument syntax:

	 *  - Add kprobe: p[:EVENT] SYMBOL[+OFFS|-OFFS]|ADDRESS [FETCHARGS]

	 *  - Add kprobe: p[:EVENT] SYMBOL[+OFFS]|ADDRESS [FETCHARGS]

	 *  - Add kretprobe: r[:EVENT] SYMBOL[+0] [FETCHARGS]

	 * Fetch args:

	 *  aN	: fetch Nth of function argument. (N:0-)
@@ -539,7 +534,7 @@ static int create_trace_probe(int argc, char **argv) 
	int i, ret = 0;

	int is_return = 0;

	char *symbol = NULL, *event = NULL;

	long offset = 0;

	unsigned long offset = 0;

	void *addr = NULL;



	if (argc < 2)
@@ -605,7 +600,7 @@ static int create_trace_probe(int argc, char **argv) 


	if (tp->symbol) {

		kp->symbol_name = tp->symbol;

		kp->offset = offset;

		kp->offset = (unsigned int)offset;

	} else

		kp->addr = addr;
@@ -675,7 +670,7 @@ static int probes_seq_show(struct seq_file *m, void *v) 
	seq_printf(m, ":%s", tp->call.name);



	if (tp->symbol)

		seq_printf(m, " %s%+ld", probe_symbol(tp), probe_offset(tp));

		seq_printf(m, " %s+%u", probe_symbol(tp), probe_offset(tp));

	else

		seq_printf(m, " 0x%p", probe_address(tp));