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[binutils-gdb] Fix GDB crash in dprintf.exp
- From: Yao Qi <qiyao at sourceware dot org>
- To: gdb-cvs at sourceware dot org
- Date: 28 Jan 2016 14:17:31 -0000
- Subject: [binutils-gdb] Fix GDB crash in dprintf.exp
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=4a6a1ed4a113d386b131938bbc7d66e7b495e73f
commit 4a6a1ed4a113d386b131938bbc7d66e7b495e73f
Author: Yao Qi <yao.qi@linaro.org>
Date: Thu Jan 28 14:16:42 2016 +0000
Fix GDB crash in dprintf.exp
I see GDB crashes in dprintf.exp on aarch64-linux testing,
(gdb) PASS: gdb.base/dprintf.exp: agent: break 29
set dprintf-style agent^M
(gdb) PASS: gdb.base/dprintf.exp: agent: set dprintf style to agent
continue^M
Continuing.
ASAN:SIGSEGV
=================================================================
==22475==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000008 (pc 0x000000494820 sp 0x7fff389b83a0 bp 0x62d000082417 T0)
#0 0x49481f in remote_add_target_side_commands /home/yao/SourceCode/gnu/gdb/git/gdb/remote.c:9190^M
#1 0x49e576 in remote_add_target_side_commands /home/yao/SourceCode/gnu/gdb/git/gdb/remote.c:9174^M
#2 0x49e576 in remote_insert_breakpoint /home/yao/SourceCode/gnu/gdb/git/gdb/remote.c:9240^M
#3 0x5278b7 in insert_bp_location /home/yao/SourceCode/gnu/gdb/git/gdb/breakpoint.c:2734^M
#4 0x52ac09 in insert_breakpoint_locations /home/yao/SourceCode/gnu/gdb/git/gdb/breakpoint.c:3159^M
#5 0x52ac09 in update_global_location_list /home/yao/SourceCode/gnu/gdb/git/gdb/breakpoint.c:12686
the root cause of this problem in this case is about linespec and
symtab which produces additional incorrect location and a NULL is added to
bp_tgt->tcommands. I posted a patch
https://sourceware.org/ml/gdb-patches/2015-12/msg00321.html to fix it
in linespec (the fix causes regression), but GDB still shouldn't add
NULL into bp_tgt->tcommands. The logic of build_target_command_list
looks odd to me. If we get something wrong in parse_cmd_to_aexpr (it
returns NULL), we shouldn't continue, instead we should set flag
null_command_or_parse_error. This is what this patch does. In the
meantime, we find build_target_condition_list has the same problem, so
fix it too.
gdb:
2016-01-28 Yao Qi <yao.qi@linaro.org>
* breakpoint.c (build_target_command_list): Don't call continue
if aexpr is NULL.
(build_target_condition_list): Likewise.
Diff:
---
gdb/ChangeLog | 6 ++++++
gdb/breakpoint.c | 9 ---------
2 files changed, 6 insertions(+), 9 deletions(-)
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 0958c5b..065319c 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+2016-01-28 Yao Qi <yao.qi@linaro.org>
+
+ * breakpoint.c (build_target_command_list): Don't call continue
+ if aexpr is NULL.
+ (build_target_condition_list): Likewise.
+
2016-01-27 Kevin Buettner <kevinb@redhat.com>
* rx-tdep.c (rx_push_dummy_call): Treat scalars larger than 8
diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index 7b610ef..afd9065 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -2347,12 +2347,6 @@ build_target_condition_list (struct bp_location *bl)
need to parse the condition to bytecodes again. */
aexpr = parse_cond_to_aexpr (bl->address, loc->cond);
loc->cond_bytecode = aexpr;
-
- /* Check if we managed to parse the conditional expression
- correctly. If not, we will not send this condition
- to the target. */
- if (aexpr)
- continue;
}
/* If we have a NULL bytecode expression, it means something
@@ -2553,9 +2547,6 @@ build_target_command_list (struct bp_location *bl)
aexpr = parse_cmd_to_aexpr (bl->address,
loc->owner->extra_string);
loc->cmd_bytecode = aexpr;
-
- if (!aexpr)
- continue;
}
/* If we have a NULL bytecode expression, it means something