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Re: [RFA] Initialize py_type_printers in ext_lang_type_printers
- From: Phil Muldoon <pmuldoon at redhat dot com>
- To: Tom Tromey <tom at tromey dot com>, gdb-patches at sourceware dot org
- Date: Thu, 17 May 2018 11:32:40 +0100
- Subject: Re: [RFA] Initialize py_type_printers in ext_lang_type_printers
- References: <20180516174302.29092-1-tom@tromey.com>
On 16/05/18 18:43, Tom Tromey wrote:
> When running gdb in the build directory without passing
> --data-directory, I noticed I could provoke a crash by:
>
> $ ./gdb -nx ./gdb
> (gdb) ptype/o struct dwarf2_per_objfile
>
> ... and then trying to "q" out at the pagination prompt.
>
> valgrind complained about an uninitialized use of py_type_printers.
> Initializing this member fixes the bug.
>
> I believe this bug can occur even when the gdb Python libraries are
> available, for example if get_type_recognizers fails.
>
> Tested by hand on x86-64 Fedora 26. No test case because it seemed
> difficult to guarantee failures.
>
> gdb/ChangeLog
> 2018-05-16 Tom Tromey <tom@tromey.com>
>
> * extension.h (struct ext_lang_type_printers) <py_type_printers>:
> Initialize.
> ---
> gdb/ChangeLog | 5 +++++
> gdb/extension.h | 2 +-
> 2 files changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/gdb/extension.h b/gdb/extension.h
> index abde5e54e1..0c8c4ee934 100644
> --- a/gdb/extension.h
> +++ b/gdb/extension.h
> @@ -152,7 +152,7 @@ struct ext_lang_type_printers
> DISABLE_COPY_AND_ASSIGN (ext_lang_type_printers);
>
> /* Type-printers from Python. */
> - void *py_type_printers;
> + void *py_type_printers = nullptr;
> };
>
> /* The return code for some API calls. */
>
LGTM
Cheers
Phil