From: Masami Hiramatsu <[email protected]> The commit 05c8d802fa52 ("perf probe: Fix to free temporal Dwarf_Frame") tried to fix the memory leak of Dwarf_Frame, but it released the frame at wrong point. Since the dwarf_frame_cfa(frame, &pf->fb_ops, &nops) can return an address inside the frame data structure to pf->fb_ops, we can not release the frame before using pf->fb_ops.
This reverts the commit and releases the frame afterwards (right before returning from call_probe_finder) correctly. Reported-and-Tested-by: Arnaldo Carvalho de Melo <[email protected]> Reported-by: Michael Petlan <[email protected]> Signed-off-by: Masami Hiramatsu <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: David Ahern <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Wang Nan <[email protected]> Fixes: 05c8d802fa52 ("perf probe: Fix to free temporal Dwarf_Frame") LPU-Reference: [email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> --- tools/perf/util/probe-finder.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index 1cab05a3831e..2be10fb27172 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -654,6 +654,7 @@ static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod, static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf) { Dwarf_Attribute fb_attr; + Dwarf_Frame *frame = NULL; size_t nops; int ret; @@ -683,26 +684,24 @@ static int call_probe_finder(Dwarf_Die *sc_die, struct probe_finder *pf) ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1); if (ret <= 0 || nops == 0) { pf->fb_ops = NULL; - ret = 0; #if _ELFUTILS_PREREQ(0, 142) } else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa && pf->cfi != NULL) { - Dwarf_Frame *frame = NULL; if (dwarf_cfi_addrframe(pf->cfi, pf->addr, &frame) != 0 || dwarf_frame_cfa(frame, &pf->fb_ops, &nops) != 0) { pr_warning("Failed to get call frame on 0x%jx\n", (uintmax_t)pf->addr); - ret = -ENOENT; + free(frame); + return -ENOENT; } - free(frame); #endif } /* Call finder's callback handler */ - if (ret >= 0) - ret = pf->callback(sc_die, pf); + ret = pf->callback(sc_die, pf); - /* *pf->fb_ops will be cached in libdw. Don't free it. */ + /* Since *pf->fb_ops can be a part of frame. we should free it here. */ + free(frame); pf->fb_ops = NULL; return ret; -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
