Em Tue, Oct 19, 2021 at 11:42:00AM +0100, Douglas RAILLARD escreveu:
> From: Douglas Raillard <douglas.raillard@xxxxxxx>
>
> Add a --skip_missing option that allows pahole to keep going in case one
> of the type passed to -C (e.g. via a file) does not exist.
>
> This is useful for intropsection software such as debugging kernel
> modules that can handle various kernel configurations and versions for
> which some recently added types are missing. The consumer of the header
> becomes responsible of gating the uses of the type with #ifdef
> CONFIG_XXX, rather than pahole bailing out on the first unknown type.
Cherry picking this out of order, as its easy to review:
Committer testing:
Before:
$ pahole tcp_splice_state,xxfrm_policy_queue,list_head tcp.o
struct tcp_splice_state {
struct pipe_inode_info * pipe; /* 0 8 */
size_t len; /* 8 8 */
unsigned int flags; /* 16 4 */
/* size: 24, cachelines: 1, members: 3 */
/* padding: 4 */
/* last cacheline: 24 bytes */
};
pahole: type 'xxfrm_policy_queue' not found
$
After:
$ pahole --help |& grep skip
--skip=COUNT Skip COUNT input records
--skip_encoding_btf_tag Do not encode TAGs in BTF.
--skip_encoding_btf_vars Do not encode VARs in BTF.
--skip_missing skip missing types passed to -C rather than stop
$ pahole --skip_missing tcp_splice_state,xxfrm_policy_queue,list_head tcp.o
struct tcp_splice_state {
struct pipe_inode_info * pipe; /* 0 8 */
size_t len; /* 8 8 */
unsigned int flags; /* 16 4 */
/* size: 24, cachelines: 1, members: 3 */
/* padding: 4 */
/* last cacheline: 24 bytes */
};
struct list_head {
struct list_head * next; /* 0 8 */
struct list_head * prev; /* 8 8 */
/* size: 16, cachelines: 1, members: 2 */
/* last cacheline: 16 bytes */
};
pahole: type 'xxfrm_policy_queue' not found
$
Signed-off-by: Douglas Raillard <douglas.raillard@xxxxxxx>
Tested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> Signed-off-by: Douglas Raillard <douglas.raillard@xxxxxxx>
> ---
> dwarves.h | 2 ++
> pahole.c | 17 +++++++++++++++--
> 2 files changed, 17 insertions(+), 2 deletions(-)
>
> diff --git a/dwarves.h b/dwarves.h
> index 30d33fa..6be6094 100644
> --- a/dwarves.h
> +++ b/dwarves.h
> @@ -43,6 +43,7 @@ struct conf_fprintf;
> * @get_addr_info - wheter to load DW_AT_location and other addr info
> * @nr_jobs - -j argument, number of threads to use
> * @ptr_table_stats - print developer oriented ptr_table statistics.
> + * @skip_missing - skip missing types rather than bailing out.
> */
> struct conf_load {
> enum load_steal_kind (*steal)(struct cu *cu,
> @@ -59,6 +60,7 @@ struct conf_load {
> bool ignore_labels;
> bool ptr_table_stats;
> bool skip_encoding_btf_tag;
> + bool skip_missing;
> uint8_t hashtable_bits;
> uint8_t max_hashtable_bits;
> uint16_t kabi_prefix_len;
> diff --git a/pahole.c b/pahole.c
> index 80271b5..68e3c8a 100644
> --- a/pahole.c
> +++ b/pahole.c
> @@ -1125,6 +1125,7 @@ ARGP_PROGRAM_VERSION_HOOK_DEF = dwarves_print_version;
> #define ARGP_hashbits 329
> #define ARGP_devel_stats 330
> #define ARGP_skip_encoding_btf_tag 331
> +#define ARGP_skip_missing 332
>
> static const struct argp_option pahole__options[] = {
> {
> @@ -1500,6 +1501,11 @@ static const struct argp_option pahole__options[] = {
> .key = ARGP_skip_encoding_btf_tag,
> .doc = "Do not encode TAGs in BTF."
> },
> + {
> + .name = "skip_missing",
> + .key = ARGP_skip_missing,
> + .doc = "skip missing types passed to -C rather than stop",
> + },
> {
> .name = NULL,
> }
> @@ -1650,6 +1656,8 @@ static error_t pahole__options_parser(int key, char *arg,
> conf_load.ptr_table_stats = true; break;
> case ARGP_skip_encoding_btf_tag:
> conf_load.skip_encoding_btf_tag = true; break;
> + case ARGP_skip_missing:
> + conf_load.skip_missing = true; break;
> default:
> return ARGP_ERR_UNKNOWN;
> }
> @@ -2879,8 +2887,13 @@ out_btf:
> static type_id_t class_id;
> struct tag *class = cu__find_type_by_name(cu, prototype->name, include_decls, &class_id);
>
> - if (class == NULL)
> - return ret; // couldn't find that class name in this CU, continue to the next one.
> + // couldn't find that class name in this CU, continue to the next one.
> + if (class == NULL) {
> + if (conf_load->skip_missing)
> + continue;
> + else
> + return ret;
> + }
>
> if (prototype->nr_args != 0 && !tag__is_struct(class)) {
> fprintf(stderr, "pahole: attributes are only supported with 'class' and 'struct' types\n");
> --
> 2.25.1
--
- Arnaldo
