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[PATCH] gdb: remove local extern declaration of cli_styling
- From: Simon Marchi <simon dot marchi at polymtl dot ca>
- To: gdb-patches at sourceware dot org
- Cc: Simon Marchi <simon dot marchi at polymtl dot ca>
- Date: Tue, 17 Sep 2019 23:05:33 -0400
- Subject: [PATCH] gdb: remove local extern declaration of cli_styling
Following the int -> bool conversion of boolean options (commit
491144b5e21b ("Change boolean options to bool instead of int")), I see
this ASAN error:
==357543==ERROR: AddressSanitizer: global-buffer-overflow on address 0x55555b25d440 at pc 0x5555583ce9e1 bp 0x7fffffffd390 sp 0x7fffffffd380
READ of size 4 at 0x55555b25d440 thread T0
#0 0x5555583ce9e0 in term_cli_styling /home/simark/src/binutils-gdb/gdb/ui-file.c:111
#1 0x5555583cf8b0 in stdio_file::can_emit_style_escape() /home/simark/src/binutils-gdb/gdb/ui-file.c:308
#2 0x5555584450d2 in set_output_style /home/simark/src/binutils-gdb/gdb/utils.c:1442
#3 0x5555584491af in fprintf_styled(ui_file*, ui_file_style const&, char const*, ...) /home/simark/src/binutils-gdb/gdb/utils.c:2143
#4 0x5555582fa13c in print_gdb_version(ui_file*, bool) /home/simark/src/binutils-gdb/gdb/top.c:1339
#5 0x555557b723ab in captured_main_1 /home/simark/src/binutils-gdb/gdb/main.c:981
#6 0x555557b7353b in captured_main /home/simark/src/binutils-gdb/gdb/main.c:1172
#7 0x555557b735d0 in gdb_main(captured_main_args*) /home/simark/src/binutils-gdb/gdb/main.c:1197
#8 0x55555700a53d in main /home/simark/src/binutils-gdb/gdb/gdb.c:32
#9 0x7ffff64c9ee2 in __libc_start_main (/usr/lib/libc.so.6+0x26ee2)
#10 0x55555700a30d in _start (/home/simark/build/binutils-gdb/gdb/gdb+0x1ab630d)
0x55555b25d441 is located 0 bytes to the right of global variable 'cli_styling' defined in '/home/simark/src/binutils-gdb/gdb/cli/cli-style.c:31:6' (0x55555b25d440) of size 1
The reason of this is that we have this declaration of cli_styling in cli/cli-style.h:
extern bool cli_styling;
but ui-file.c uses its own local declaration:
extern int cli_styling;
Because of that, the code in ui-file.c thinks the variable is 4 bytes
long, when it is actually 1 byte long, so the generated code reads past
the variable.
Fix it by removing the declaration and making ui-file.c include
cli/cli-style.h.
gdb/ChangeLog:
* ui-file.c: Include cli/cli-style.h.
(term_cli_styling): Remove cli_styling declaration.
---
gdb/ui-file.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/gdb/ui-file.c b/gdb/ui-file.c
index 042b13ca3b18..71b74bba1905 100644
--- a/gdb/ui-file.c
+++ b/gdb/ui-file.c
@@ -24,6 +24,7 @@
#include "gdb_obstack.h"
#include "gdb_select.h"
#include "gdbsupport/filestuff.h"
+#include "cli/cli-style.h"
null_file null_stream;
@@ -106,8 +107,6 @@ ui_file_isatty (struct ui_file *file)
static bool
term_cli_styling ()
{
- extern int cli_styling;
-
if (!cli_styling)
return false;
--
2.23.0