[PATCH] tools/perf: Fix to get the DW_AT_decl_file and DW_AT_call_file as unsinged data

From: Masami Hiramatsu (Google)
Date: Fri Nov 04 2022 - 23:01:28 EST


From: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>

Dwarf version 5 standard Sec 2.14 says that

Any debugging information entry representing the declaration of an object,
module, subprogram or type may have DW_AT_decl_file, DW_AT_decl_line and
DW_AT_decl_column attributes, each of whose value is an unsigned integer
constant.

So it should be an unsigned integer data. Also, even though the standard
doesn't clearly say the DW_AT_call_file is signed or unsigned, the
elfutils (eu-readelf) interprets it as unsigned integer data and it is
natural to handle it as unsigned integer data as same as DW_AT_decl_file.
This changes the DW_AT_call_file as unsigned integer data too.

Fixes: 3f4460a28fb2 ("perf probe: Filter out redundant inline-instances")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
---
tools/perf/util/dwarf-aux.c | 21 ++++-----------------
1 file changed, 4 insertions(+), 17 deletions(-)

diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c
index 30b36b525681..b07414409771 100644
--- a/tools/perf/util/dwarf-aux.c
+++ b/tools/perf/util/dwarf-aux.c
@@ -315,19 +315,6 @@ static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name,
return 0;
}

-/* Get attribute and translate it as a sdata */
-static int die_get_attr_sdata(Dwarf_Die *tp_die, unsigned int attr_name,
- Dwarf_Sword *result)
-{
- Dwarf_Attribute attr;
-
- if (dwarf_attr_integrate(tp_die, attr_name, &attr) == NULL ||
- dwarf_formsdata(&attr, result) != 0)
- return -ENOENT;
-
- return 0;
-}
-
/**
* die_is_signed_type - Check whether a type DIE is signed or not
* @tp_die: a DIE of a type
@@ -467,9 +454,9 @@ int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs)
/* Get the call file index number in CU DIE */
static int die_get_call_fileno(Dwarf_Die *in_die)
{
- Dwarf_Sword idx;
+ Dwarf_Word idx;

- if (die_get_attr_sdata(in_die, DW_AT_call_file, &idx) == 0)
+ if (die_get_attr_udata(in_die, DW_AT_call_file, &idx) == 0)
return (int)idx;
else
return -ENOENT;
@@ -478,9 +465,9 @@ static int die_get_call_fileno(Dwarf_Die *in_die)
/* Get the declared file index number in CU DIE */
static int die_get_decl_fileno(Dwarf_Die *pdie)
{
- Dwarf_Sword idx;
+ Dwarf_Word idx;

- if (die_get_attr_sdata(pdie, DW_AT_decl_file, &idx) == 0)
+ if (die_get_attr_udata(pdie, DW_AT_decl_file, &idx) == 0)
return (int)idx;
else
return -ENOENT;