From 237c96b8c1584d4c28d3593e5f52508fbec9ff06 Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Fri, 20 May 2022 16:24:00 +0300 Subject: [PATCH] perf header: Add ability to keep feature sections Many feature sections should not be re-written during perf inject. In preparation to support that, add callbacks that a tool can use to copy a feature section from elsewhere. perf inject will use this facility to copy features sections from the input file. Signed-off-by: Adrian Hunter Acked-by: Jiri Olsa Cc: Namhyung Kim Link: https://lore.kernel.org/r/20220520132404.25853-2-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/header.c | 54 +++++++++++++++++++++++++++++++++++++++++------- tools/perf/util/header.h | 10 +++++++++ 2 files changed, 56 insertions(+), 8 deletions(-) diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index a27132e..b0c57a1 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -3462,9 +3462,22 @@ int perf_header__fprintf_info(struct perf_session *session, FILE *fp, bool full) return 0; } +struct header_fw { + struct feat_writer fw; + struct feat_fd *ff; +}; + +static int feat_writer_cb(struct feat_writer *fw, void *buf, size_t sz) +{ + struct header_fw *h = container_of(fw, struct header_fw, fw); + + return do_write(h->ff, buf, sz); +} + static int do_write_feat(struct feat_fd *ff, int type, struct perf_file_section **p, - struct evlist *evlist) + struct evlist *evlist, + struct feat_copier *fc) { int err; int ret = 0; @@ -3478,7 +3491,23 @@ static int do_write_feat(struct feat_fd *ff, int type, (*p)->offset = lseek(ff->fd, 0, SEEK_CUR); - err = feat_ops[type].write(ff, evlist); + /* + * Hook to let perf inject copy features sections from the input + * file. + */ + if (fc && fc->copy) { + struct header_fw h = { + .fw.write = feat_writer_cb, + .ff = ff, + }; + + /* ->copy() returns 0 if the feature was not copied */ + err = fc->copy(fc, type, &h.fw); + } else { + err = 0; + } + if (!err) + err = feat_ops[type].write(ff, evlist); if (err < 0) { pr_debug("failed to write feature %s\n", feat_ops[type].name); @@ -3494,7 +3523,8 @@ static int do_write_feat(struct feat_fd *ff, int type, } static int perf_header__adds_write(struct perf_header *header, - struct evlist *evlist, int fd) + struct evlist *evlist, int fd, + struct feat_copier *fc) { int nr_sections; struct feat_fd ff; @@ -3523,7 +3553,7 @@ static int perf_header__adds_write(struct perf_header *header, lseek(fd, sec_start + sec_size, SEEK_SET); for_each_set_bit(feat, header->adds_features, HEADER_FEAT_BITS) { - if (do_write_feat(&ff, feat, &p, evlist)) + if (do_write_feat(&ff, feat, &p, evlist, fc)) perf_header__clear_feat(header, feat); } @@ -3561,9 +3591,10 @@ int perf_header__write_pipe(int fd) return 0; } -int perf_session__write_header(struct perf_session *session, - struct evlist *evlist, - int fd, bool at_exit) +static int perf_session__do_write_header(struct perf_session *session, + struct evlist *evlist, + int fd, bool at_exit, + struct feat_copier *fc) { struct perf_file_header f_header; struct perf_file_attr f_attr; @@ -3615,7 +3646,7 @@ int perf_session__write_header(struct perf_session *session, header->feat_offset = header->data_offset + header->data_size; if (at_exit) { - err = perf_header__adds_write(header, evlist, fd); + err = perf_header__adds_write(header, evlist, fd, fc); if (err < 0) return err; } @@ -3648,6 +3679,13 @@ int perf_session__write_header(struct perf_session *session, return 0; } +int perf_session__write_header(struct perf_session *session, + struct evlist *evlist, + int fd, bool at_exit) +{ + return perf_session__do_write_header(session, evlist, fd, at_exit, NULL); +} + static int perf_header__getbuffer64(struct perf_header *header, int fd, void *buf, size_t size) { diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h index 0eb4bc2..e76ab02 100644 --- a/tools/perf/util/header.h +++ b/tools/perf/util/header.h @@ -121,6 +121,16 @@ int perf_session__write_header(struct perf_session *session, int fd, bool at_exit); int perf_header__write_pipe(int fd); +/* feat_writer writes a feature section to output */ +struct feat_writer { + int (*write)(struct feat_writer *fw, void *buf, size_t sz); +}; + +/* feat_copier copies a feature section using feat_writer to output */ +struct feat_copier { + int (*copy)(struct feat_copier *fc, int feat, struct feat_writer *fw); +}; + void perf_header__set_feat(struct perf_header *header, int feat); void perf_header__clear_feat(struct perf_header *header, int feat); bool perf_header__has_feat(const struct perf_header *header, int feat); -- 2.7.4