[patch] [python] Re: GDB crashing on gdb.python/py-linetable.exp

Jan Kratochvil
2014-02-07T17:17:07Z

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On Fri, 07 Feb 2014 11:45:04 +0100, Phil Muldoon wrote:
> I've tried most of the morning to reproduce this on Fedora 19, with
> -lmcheck and after several thousand test runs I can't reproduce.

Due to the requirement of specific stack layout I found it is reproducible for
me on Fedora 20 x86_64 with (it sure could be reduced):

CFLAGS="-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic" LDFLAGS="-static-libstdc++ -static-libgcc -Wl,-z,relro" ./configure --with-system-readline;make
(ulimit -c unlimited;/usr/bin/runtest gdb.python/py-linetable.exp)

The fix is obvious, I will check it in.

- int py_line;
+ gdb_py_longest py_line;
[...]

Regards,
Jan

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gdb/
2014-02-07 Jan Kratochvil <jan.kratochvil@redhat.com>

Fix Python stack corruption.
* python/py-linetable.c (ltpy_get_pcs_for_line, ltpy_has_line): Use
gdb_py_longest.

diff --git a/gdb/python/py-linetable.c b/gdb/python/py-linetable.c
index e83d46d..8b5362b 100644
--- a/gdb/python/py-linetable.c
+++ b/gdb/python/py-linetable.c
@@ -168,7 +168,7 @@ static PyObject *
ltpy_get_pcs_for_line (PyObject *self, PyObject *args)
{
struct symtab *symtab;
- int py_line;
+ gdb_py_longest py_line;
struct linetable_entry *best_entry = NULL;
linetable_entry_object *result;
VEC (CORE_ADDR) *pcs = NULL;
@@ -200,7 +200,7 @@ static PyObject *
ltpy_has_line (PyObject *self, PyObject *args)
{
struct symtab *symtab;
- int py_line;
+ gdb_py_longest py_line;
int index;

LTPY_REQUIRE_VALID (self, symtab);