[PATCH 5.4 79/98] perf probe: Fix to die_entrypc() returns error correctly

From: Greg Kroah-Hartman
Date: Tue Dec 01 2020 - 04:24:00 EST


From: Masami Hiramatsu <mhiramat@xxxxxxxxxx>

[ Upstream commit ab4200c17ba6fe71d2da64317aae8a8aa684624c ]

Fix die_entrypc() to return error correctly if the DIE has no
DW_AT_ranges attribute. Since dwarf_ranges() will treat the case as an
empty ranges and return 0, we have to check it by ourselves.

Fixes: 91e2f539eeda ("perf probe: Fix to show function entry line as probe-able")
Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Sumanth Korikkar <sumanthk@xxxxxxxxxxxxx>
Cc: Thomas Richter <tmricht@xxxxxxxxxxxxx>
Link: http://lore.kernel.org/lkml/160645612634.2824037.5284932731175079426.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
tools/perf/util/dwarf-aux.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c
index 5544bfbd0f6c0..ab34ef2c661f8 100644
--- a/tools/perf/util/dwarf-aux.c
+++ b/tools/perf/util/dwarf-aux.c
@@ -319,6 +319,7 @@ bool die_is_func_def(Dwarf_Die *dw_die)
int die_entrypc(Dwarf_Die *dw_die, Dwarf_Addr *addr)
{
Dwarf_Addr base, end;
+ Dwarf_Attribute attr;

if (!addr)
return -EINVAL;
@@ -326,6 +327,13 @@ int die_entrypc(Dwarf_Die *dw_die, Dwarf_Addr *addr)
if (dwarf_entrypc(dw_die, addr) == 0)
return 0;

+ /*
+ * Since the dwarf_ranges() will return 0 if there is no
+ * DW_AT_ranges attribute, we should check it first.
+ */
+ if (!dwarf_attr(dw_die, DW_AT_ranges, &attr))
+ return -ENOENT;
+
return dwarf_ranges(dw_die, 0, &base, addr, &end) < 0 ? -ENOENT : 0;
}

--
2.27.0