perf probe: Fix a bug that --line range can be overflow

Since line_finder.lno_s/e are signed int but line_range.start/end
are unsigned int, it is possible to be overflow when converting
line_range->start/end to line_finder->lno_s/e.
This changes line_range.start/end and line_list.line to signed int
and adds overflow checks when setting line_finder.lno_s/e.

LKML-Reference: <20100414223942.14630.72730.stgit@localhost6.localdomain6>
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 9 insertions, 10 deletions

diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index e443e69a4d2..b4c93659929 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -111,7 +111,7 @@ static int strtailcmp(const char *s1, const char *s2)
 /* Line number list operations */
 
 /* Add a line to line number list */
-static int line_list__add_line(struct list_head *head, unsigned int line)
+static int line_list__add_line(struct list_head *head, int line)
 {
 	struct line_node *ln;
 	struct list_head *p;
@@ -138,7 +138,7 @@ found:
 }
 
 /* Check if the line in line number list */
-static int line_list__has_line(struct list_head *head, unsigned int line)
+static int line_list__has_line(struct list_head *head, int line)
 {
 	struct line_node *ln;
 
@@ -1146,7 +1146,7 @@ static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
 			if (lf->lr->path == NULL)
 				return -ENOMEM;
 		}
-		line_list__add_line(&lf->lr->line_list, (unsigned int)lineno);
+		line_list__add_line(&lf->lr->line_list, lineno);
 	}
 	/* Update status */
 	if (!list_empty(&lf->lr->line_list))
@@ -1179,10 +1179,12 @@ static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
 		dwarf_decl_line(sp_die, &lr->offset);
 		pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset);
 		lf->lno_s = lr->offset + lr->start;
-		if (!lr->end)
+		if (lf->lno_s < 0)	/* Overflow */
+			lf->lno_s = INT_MAX;
+		lf->lno_e = lr->offset + lr->end;
+		if (lf->lno_e < 0)	/* Overflow */
 			lf->lno_e = INT_MAX;
-		else
-			lf->lno_e = lr->offset + lr->end;
+		pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
 		lr->start = lf->lno_s;
 		lr->end = lf->lno_e;
 		if (dwarf_func_inline(sp_die)) {
@@ -1244,10 +1246,7 @@ int find_line_range(int fd, struct line_range *lr)
 				ret = find_line_range_by_func(&lf);
 			else {
 				lf.lno_s = lr->start;
-				if (!lr->end)
-					lf.lno_e = INT_MAX;
-				else
-					lf.lno_e = lr->end;
+				lf.lno_e = lr->end;
 				ret = find_line_range_by_line(NULL, &lf);
 			}
 		}