Re: [PATCH 2/2] perf tools: Prevent calling machine__delete() on non-allocated machine

[Wangnan (F)]

On 2015/12/10 13:52, Wang Nan wrote:
> To prevent futher commits calling machine__delete() on non-allocated
> 'struct machine' (which would cause memory corruption), this patch
> enforces machine__init(), record whether a machine structure is
> dynamically allocated or not, and warn if machine__delete() is called
> on incorrect object.
>
> Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
> Cc: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
> Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
> ---
>   tools/perf/tests/vmlinux-kallsyms.c |  4 ++--
>   tools/perf/util/machine.c           | 14 +++++++++-----
>   tools/perf/util/machine.h           |  3 ++-
>   3 files changed, 13 insertions(+), 8 deletions(-)
>
> diff --git a/tools/perf/tests/vmlinux-kallsyms.c b/tools/perf/tests/vmlinux-kallsyms.c
> index f0bfc9e..441e93d 100644
> --- a/tools/perf/tests/vmlinux-kallsyms.c
> +++ b/tools/perf/tests/vmlinux-kallsyms.c
> @@ -35,8 +35,8 @@ int test__vmlinux_matches_kallsyms(int subtest __maybe_unused)
>   	 * Init the machines that will hold kernel, modules obtained from
>   	 * both vmlinux + .ko files and from /proc/kallsyms split by modules.
>   	 */
> -	machine__init(&kallsyms, "", HOST_KERNEL_ID);
> -	machine__init(&vmlinux, "", HOST_KERNEL_ID);
> +	machine__init(&kallsyms, "", HOST_KERNEL_ID, false);
> +	machine__init(&vmlinux, "", HOST_KERNEL_ID, false);
>   
>   	/*
>   	 * Step 2:
> diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
> index f5882b8..a2b9b47 100644
> --- a/tools/perf/util/machine.c
> +++ b/tools/perf/util/machine.c
> @@ -23,7 +23,7 @@ static void dsos__init(struct dsos *dsos)
>   	pthread_rwlock_init(&dsos->lock, NULL);
>   }
>   
> -int machine__init(struct machine *machine, const char *root_dir, pid_t pid)
> +int machine__init(struct machine *machine, const char *root_dir, pid_t pid, bool allocated)
>   {
>   	map_groups__init(&machine->kmaps, machine);
>   	RB_CLEAR_NODE(&machine->rb_node);
> @@ -64,6 +64,7 @@ int machine__init(struct machine *machine, const char *root_dir, pid_t pid)
>   	}
>   
>   	machine->current_tid = NULL;
> +	machine->allocated = allocated;
>   
>   	return 0;
>   }
> @@ -73,7 +74,7 @@ struct machine *machine__new_host(void)
>   	struct machine *machine = malloc(sizeof(*machine));
>   
>   	if (machine != NULL) {
> -		machine__init(machine, "", HOST_KERNEL_ID);
> +		machine__init(machine, "", HOST_KERNEL_ID, true);
>   
>   		if (machine__create_kernel_maps(machine) < 0)
>   			goto out_delete;
> @@ -136,12 +137,15 @@ void machine__exit(struct machine *machine)
>   void machine__delete(struct machine *machine)
>   {
>   	machine__exit(machine);
> -	free(machine);
> +	if (!machine->allocated)
Sorry, should be

        if (machine->allocated)

Will send v2.

Thank you.

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