[tip:perf/probes] tracing/kprobes: Fix probe offset to be unsigned

From: tip-bot for Masami Hiramatsu
Date: Sat Oct 17 2009 - 06:00:31 EST


Commit-ID: 2fba0c8867af47f6455490e7b59e512dd180c027
Gitweb: http://git.kernel.org/tip/2fba0c8867af47f6455490e7b59e512dd180c027
Author: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
AuthorDate: Thu, 10 Sep 2009 19:53:14 -0400
Committer: Frederic Weisbecker <fweisbec@xxxxxxxxx>
CommitDate: Fri, 11 Sep 2009 04:18:58 +0200

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: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Jim Keniston <jkenisto@xxxxxxxxxx>
Cc: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Cc: Frank Ch. Eigler <fche@xxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Jason Baron <jbaron@xxxxxxxxxx>
Cc: K.Prasad <prasad@xxxxxxxxxxxxxxxxxx>
Cc: Lai Jiangshan <laijs@xxxxxxxxxxxxxx>
Cc: Li Zefan <lizf@xxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Tom Zanussi <tzanussi@xxxxxxxxx>
LKML-Reference: <20090910235314.22412.64631.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
---
Documentation/trace/kprobetrace.txt | 14 +++++++-------
kernel/trace/trace_kprobe.c | 19 +++++++------------
2 files changed, 14 insertions(+), 19 deletions(-)

diff --git a/Documentation/trace/kprobetrace.txt b/Documentation/trace/kprobetrace.txt
index 3de7517..db55318 100644
--- a/Documentation/trace/kprobetrace.txt
+++ b/Documentation/trace/kprobetrace.txt
@@ -25,15 +25,15 @@ 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
- r[:EVENT] SYMBOL[+0] [FETCHARGS] : Set a return 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.
- MEMADDR : Address where the probe is inserted.
+ EVENT : Event name. If omitted, the event name is generated
+ based on SYMBOL+offs or MEMADDR.
+ 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.
+ FETCHARGS : Arguments. Each probe can have up to 128 args.
%REG : Fetch register REG
sN : Fetch Nth entry of stack (N >= 0)
sa : Fetch stack address.
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 19a6de6..c24b7e9 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -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 @@ end:
}

/* 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));

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