Commit 900547dd authored Feb 03, 2021 by Jianlin Lv Committed by Arnaldo Carvalho de Melo Feb 08, 2021

perf probe: Add protection to avoid endless loop



if dwarf_offdie() returns NULL, the continue statement forces the next
iteration of the loop without updating the 'off' variable. It will cause
an endless loop in the process of traversing the compile unit.  So add
exception protection for looping CUs.

Signed-off-by: Jianlin Lv <Jianlin.Lv@arm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: jianlin.lv@arm.com
Link: http://lore.kernel.org/lkml/20210203145702.1219509-1-Jianlin.Lv@arm.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

parent d2e31d7e

tools/perf/util/probe-finder.c

+6 −2

Original line number	Diff line number	Diff line
		@@ -1187,8 +1187,10 @@ static int debuginfo__find_probe_location(struct debuginfo *dbg,
		while (!dwarf_nextcu(dbg->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
		/* Get the DIE(Debugging Information Entry) of this CU */
		diep = dwarf_offdie(dbg->dbg, off + cuhl, &pf->cu_die);
		if (!diep)
		if (!diep) {
		off = noff;
		continue;
		}

		/* Check if target file is included. */
		if (pp->file)
		@@ -1949,8 +1951,10 @@ int debuginfo__find_line_range(struct debuginfo dbg, struct line_range lr)

		/* Get the DIE(Debugging Information Entry) of this CU */
		diep = dwarf_offdie(dbg->dbg, off + cuhl, &lf.cu_die);
		if (!diep)
		if (!diep) {
		off = noff;
		continue;
		}

		/* Check if target file is included. */
		if (lr->file)