[PATCH 3/7] perf header: use struct feat_fd for write

From: David Carrillo-Cisneros
Date: Thu May 18 2017 - 00:17:48 EST

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As preparation for using header records in pipe mode, replace
int fd with struct feat_fd fd in write functions for all header
record types.

Record types that are not used in pipe-mode (such as auxtrace) will
never be called with fd->buf set and fail if so.

Signed-off-by: David Carrillo-Cisneros <davidcc@xxxxxxxxxx>
---
tools/perf/util/build-id.c | 10 ++-
tools/perf/util/build-id.h | 4 +-
tools/perf/util/header.c | 194 +++++++++++++++++++++++++++++----------------
tools/perf/util/header.h | 7 +-
4 files changed, 140 insertions(+), 75 deletions(-)

diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
index 168cc49654e7..292e90db3924 100644
--- a/tools/perf/util/build-id.c
+++ b/tools/perf/util/build-id.c
@@ -330,7 +330,7 @@ bool dso__build_id_is_kmod(const struct dso *dso, char *bf, size_t size)
else

static int write_buildid(const char *name, size_t name_len, u8 *build_id,
- pid_t pid, u16 misc, int fd)
+ pid_t pid, u16 misc, struct feat_fd *fd)
{
int err;
struct build_id_event b;
@@ -345,14 +345,15 @@ static int write_buildid(const char *name, size_t name_len, u8 *build_id,
b.header.misc = misc;
b.header.size = sizeof(b) + len;

- err = writen(fd, &b, sizeof(b));
+ err = do_write(fd, &b, sizeof(b));
if (err < 0)
return err;

return write_padded(fd, name, name_len + 1, len);
}

-static int machine__write_buildid_table(struct machine *machine, int fd)
+static int machine__write_buildid_table(struct machine *machine,
+ struct feat_fd *fd)
{
int err = 0;
char nm[PATH_MAX];
@@ -397,7 +398,8 @@ static int machine__write_buildid_table(struct machine *machine, int fd)
return err;
}

-int perf_session__write_buildid_table(struct perf_session *session, int fd)
+int perf_session__write_buildid_table(struct perf_session *session,
+ struct feat_fd *fd)
{
struct rb_node *nd;
int err = machine__write_buildid_table(&session->machines.host, fd);
diff --git a/tools/perf/util/build-id.h b/tools/perf/util/build-id.h
index a96081121179..84e5e8a52970 100644
--- a/tools/perf/util/build-id.h
+++ b/tools/perf/util/build-id.h
@@ -9,6 +9,7 @@

extern struct perf_tool build_id__mark_dso_hit_ops;
struct dso;
+struct feat_fd;

int build_id__sprintf(const u8 *build_id, int len, char *bf);
int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id);
@@ -26,7 +27,8 @@ int build_id__mark_dso_hit(struct perf_tool *tool, union perf_event *event,
int dsos__hit_all(struct perf_session *session);

bool perf_session__read_build_ids(struct perf_session *session, bool with_hits);
-int perf_session__write_buildid_table(struct perf_session *session, int fd);
+int perf_session__write_buildid_table(struct perf_session *session,
+ struct feat_fd *fd);
int perf_session__cache_build_ids(struct perf_session *session);

char *build_id_cache__origname(const char *sbuild_id);
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 2415d41282d8..5ca603b7a7a3 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -57,6 +57,14 @@ struct perf_file_attr {
struct perf_file_section ids;
};

+struct feat_fd {
+ struct perf_header *ph;
+ int fd;
+ void *buf; /* Either buf != NULL or fd >= 0 */
+ ssize_t offset;
+ size_t size;
+};
+
void perf_header__set_feat(struct perf_header *header, int feat)
{
set_bit(feat, header->adds_features);
@@ -73,23 +81,36 @@ bool perf_header__has_feat(const struct perf_header *header, int feat)
}

/* Return: 0 if succeded, -ERR if failed. */
-static int do_write(int fd, const void *buf, size_t size)
+int do_write(struct feat_fd *fd, const void *buf, size_t size)
{
- while (size) {
- int ret = write(fd, buf, size);
+ void *addr;

- if (ret < 0)
- return -errno;
+ if (!fd->buf) {
+ ssize_t ret = writen(fd->fd, buf, size);

- size -= ret;
- buf += ret;
+ if (ret != (ssize_t)size)
+ return ret < 0 ? (int)ret : -1;
+ return 0;
}
+retry:
+ if (size > (fd->size - fd->offset)) {
+ addr = realloc(fd->buf, fd->size << 1);
+ if (!addr)
+ return -ENOSPC;
+ fd->buf = addr;
+ fd->size <<= 1;
+ goto retry;
+ }
+
+ memcpy(fd->buf + fd->offset, buf, size);
+ fd->offset += size;

return 0;
}

/* Return: 0 if succeded, -ERR if failed. */
-int write_padded(int fd, const void *bf, size_t count, size_t count_aligned)
+int write_padded(struct feat_fd *fd, const void *bf,
+ size_t count, size_t count_aligned)
{
static const char zero_buf[NAME_ALIGN];
int err = do_write(fd, bf, count);
@@ -104,7 +125,7 @@ int write_padded(int fd, const void *bf, size_t count, size_t count_aligned)
(PERF_ALIGN((strlen(str) + 1), NAME_ALIGN) + sizeof(u32))

/* Return: 0 if succeded, -ERR if failed. */
-static int do_write_string(int fd, const char *str)
+static int do_write_string(struct feat_fd *fd, const char *str)
{
u32 len, olen;
int ret;
@@ -151,24 +172,31 @@ static char *do_read_string(int fd, struct perf_header *ph)
return NULL;
}

-static int write_tracing_data(int fd, struct perf_header *h __maybe_unused,
- struct perf_evlist *evlist)
+static int write_tracing_data(struct feat_fd *fd,
+ struct perf_evlist *evlist)
{
- return read_tracing_data(fd, &evlist->entries);
+ if (fd->buf) {
+ pr_err("Unsupported write_tracing_data to memory buffer.\n");
+ return -1;
+ }
+ return read_tracing_data(fd->fd, &evlist->entries);
}

-
-static int write_build_id(int fd, struct perf_header *h,
+static int write_build_id(struct feat_fd *fd,
struct perf_evlist *evlist __maybe_unused)
{
struct perf_session *session;
int err;

- session = container_of(h, struct perf_session, header);
+ session = container_of(fd->ph, struct perf_session, header);

if (!perf_session__read_build_ids(session, true))
return -1;

+ if (fd->buf) {
+ pr_err("Unsupported write_build_id to memory buffer.\n");
+ return -1;
+ }
err = perf_session__write_buildid_table(session, fd);
if (err < 0) {
pr_debug("failed to write buildid table\n");
@@ -179,7 +207,7 @@ static int write_build_id(int fd, struct perf_header *h,
return 0;
}

-static int write_hostname(int fd, struct perf_header *h __maybe_unused,
+static int write_hostname(struct feat_fd *fd,
struct perf_evlist *evlist __maybe_unused)
{
struct utsname uts;
@@ -192,7 +220,7 @@ static int write_hostname(int fd, struct perf_header *h __maybe_unused,
return do_write_string(fd, uts.nodename);
}

-static int write_osrelease(int fd, struct perf_header *h __maybe_unused,
+static int write_osrelease(struct feat_fd *fd,
struct perf_evlist *evlist __maybe_unused)
{
struct utsname uts;
@@ -205,7 +233,7 @@ static int write_osrelease(int fd, struct perf_header *h __maybe_unused,
return do_write_string(fd, uts.release);
}

-static int write_arch(int fd, struct perf_header *h __maybe_unused,
+static int write_arch(struct feat_fd *fd,
struct perf_evlist *evlist __maybe_unused)
{
struct utsname uts;
@@ -218,13 +246,13 @@ static int write_arch(int fd, struct perf_header *h __maybe_unused,
return do_write_string(fd, uts.machine);
}

-static int write_version(int fd, struct perf_header *h __maybe_unused,
+static int write_version(struct feat_fd *fd,
struct perf_evlist *evlist __maybe_unused)
{
return do_write_string(fd, perf_version_string);
}

-static int __write_cpudesc(int fd, const char *cpuinfo_proc)
+static int __write_cpudesc(struct feat_fd *fd, const char *cpuinfo_proc)
{
FILE *file;
char *buf = NULL;
@@ -281,7 +309,7 @@ static int __write_cpudesc(int fd, const char *cpuinfo_proc)
return ret;
}

-static int write_cpudesc(int fd, struct perf_header *h __maybe_unused,
+static int write_cpudesc(struct feat_fd *fd,
struct perf_evlist *evlist __maybe_unused)
{
#ifndef CPUINFO_PROC
@@ -300,7 +328,7 @@ static int write_cpudesc(int fd, struct perf_header *h __maybe_unused,
}

-static int write_nrcpus(int fd, struct perf_header *h __maybe_unused,
+static int write_nrcpus(struct feat_fd *fd,
struct perf_evlist *evlist __maybe_unused)
{
long nr;
@@ -322,7 +350,7 @@ static int write_nrcpus(int fd, struct perf_header *h __maybe_unused,
return do_write(fd, &nra, sizeof(nra));
}

-static int write_event_desc(int fd, struct perf_header *h __maybe_unused,
+static int write_event_desc(struct feat_fd *fd,
struct perf_evlist *evlist)
{
struct perf_evsel *evsel;
@@ -378,7 +406,7 @@ static int write_event_desc(int fd, struct perf_header *h __maybe_unused,
return 0;
}

-static int write_cmdline(int fd, struct perf_header *h __maybe_unused,
+static int write_cmdline(struct feat_fd *fd,
struct perf_evlist *evlist __maybe_unused)
{
char buf[MAXPATHLEN];
@@ -558,8 +586,8 @@ static struct cpu_topo *build_cpu_topology(void)
return tp;
}

-static int write_cpu_topology(int fd, struct perf_header *h __maybe_unused,
- struct perf_evlist *evlist __maybe_unused)
+static int write_cpu_topology(struct feat_fd *fd,
+ struct perf_evlist *evlist __maybe_unused)
{
struct cpu_topo *tp;
u32 i;
@@ -609,8 +637,8 @@ static int write_cpu_topology(int fd, struct perf_header *h __maybe_unused,

-static int write_total_mem(int fd, struct perf_header *h __maybe_unused,
- struct perf_evlist *evlist __maybe_unused)
+static int write_total_mem(struct feat_fd *fd,
+ struct perf_evlist *evlist __maybe_unused)
{
char *buf = NULL;
FILE *fp;
@@ -638,7 +666,7 @@ static int write_total_mem(int fd, struct perf_header *h __maybe_unused,
return ret;
}

-static int write_topo_node(int fd, int node)
+static int write_topo_node(struct feat_fd *fd, int node)
{
char str[MAXPATHLEN];
char field[32];
@@ -698,8 +726,8 @@ static int write_topo_node(int fd, int node)
return ret;
}

-static int write_numa_topology(int fd, struct perf_header *h __maybe_unused,
- struct perf_evlist *evlist __maybe_unused)
+static int write_numa_topology(struct feat_fd *fd,
+ struct perf_evlist *evlist __maybe_unused)
{
char *buf = NULL;
size_t len = 0;
@@ -759,15 +787,23 @@ static int write_numa_topology(int fd, struct perf_header *h __maybe_unused,
* };
*/

-static int write_pmu_mappings(int fd, struct perf_header *h __maybe_unused,
+static int write_pmu_mappings(struct feat_fd *fd,
struct perf_evlist *evlist __maybe_unused)
{
struct perf_pmu *pmu = NULL;
- off_t offset = lseek(fd, 0, SEEK_CUR);
- __u32 pmu_num = 0;
+ u32 pmu_num = 0;
int ret;

- /* write real pmu_num later */
+ /*
+ * Do a first pass to count number of pmu to avoid lseek so this
+ * works in pipe mode as well.
+ */
+ while ((pmu = perf_pmu__scan(pmu))) {
+ if (!pmu->name)
+ continue;
+ pmu_num++;
+ }
+
ret = do_write(fd, &pmu_num, sizeof(pmu_num));
if (ret < 0)
return ret;
@@ -775,7 +811,6 @@ static int write_pmu_mappings(int fd, struct perf_header *h __maybe_unused,
while ((pmu = perf_pmu__scan(pmu))) {
if (!pmu->name)
continue;
- pmu_num++;

ret = do_write(fd, &pmu->type, sizeof(pmu->type));
if (ret < 0)
@@ -786,12 +821,6 @@ static int write_pmu_mappings(int fd, struct perf_header *h __maybe_unused,
return ret;
}

- if (pwrite(fd, &pmu_num, sizeof(pmu_num), offset) != sizeof(pmu_num)) {
- /* discard all */
- lseek(fd, offset, SEEK_SET);
- return -1;
- }
-
return 0;
}

@@ -807,7 +836,7 @@ static int write_pmu_mappings(int fd, struct perf_header *h __maybe_unused,
* }[nr_groups];
* };
*/
-static int write_group_desc(int fd, struct perf_header *h __maybe_unused,
+static int write_group_desc(struct feat_fd *fd,
struct perf_evlist *evlist)
{
u32 nr_groups = evlist->nr_groups;
@@ -850,7 +879,7 @@ int __weak get_cpuid(char *buffer __maybe_unused, size_t sz __maybe_unused)
return -1;
}

-static int write_cpuid(int fd, struct perf_header *h __maybe_unused,
+static int write_cpuid(struct feat_fd *fd,
struct perf_evlist *evlist __maybe_unused)
{
char buffer[64];
@@ -865,22 +894,25 @@ static int write_cpuid(int fd, struct perf_header *h __maybe_unused,
return do_write_string(fd, buffer);
}

-static int write_branch_stack(int fd __maybe_unused,
- struct perf_header *h __maybe_unused,
- struct perf_evlist *evlist __maybe_unused)
+static int write_branch_stack(struct feat_fd *fd __maybe_unused,
+ struct perf_evlist *evlist __maybe_unused)
{
return 0;
}

-static int write_auxtrace(int fd, struct perf_header *h,
+static int write_auxtrace(struct feat_fd *fd,
struct perf_evlist *evlist __maybe_unused)
{
struct perf_session *session;
int err;

- session = container_of(h, struct perf_session, header);
+ if (fd->buf) {
+ pr_err("Unsupported write_auxtrace to memory buffer.\n");
+ return -1;
+ }
+ session = container_of(fd->ph, struct perf_session, header);

- err = auxtrace_index__write(fd, &session->auxtrace_index);
+ err = auxtrace_index__write(fd->fd, &session->auxtrace_index);
if (err < 0)
pr_err("Failed to write auxtrace index\n");
return err;
@@ -1027,8 +1059,8 @@ static int build_caches(struct cpu_cache_level caches[], u32 size, u32 *cntp)

#define MAX_CACHES 2000

-static int write_cache(int fd, struct perf_header *h __maybe_unused,
- struct perf_evlist *evlist __maybe_unused)
+static int write_cache(struct feat_fd *fd,
+ struct perf_evlist *evlist __maybe_unused)
{
struct cpu_cache_level caches[MAX_CACHES];
u32 cnt = 0, i, version = 1;
@@ -1079,8 +1111,7 @@ static int write_cache(int fd, struct perf_header *h __maybe_unused,
return ret;
}

-static int write_stat(int fd __maybe_unused,
- struct perf_header *h __maybe_unused,
+static int write_stat(struct feat_fd *fd __maybe_unused,
struct perf_evlist *evlist __maybe_unused)
{
return 0;
@@ -2186,7 +2217,7 @@ static int process_cache(struct perf_file_section *section __maybe_unused,
}

struct feature_ops {
- int (*write)(int fd, struct perf_header *h, struct perf_evlist *evlist);
+ int (*write)(struct feat_fd *fd, struct perf_evlist *evlist);
void (*print)(struct perf_header *h, int fd, FILE *fp);
int (*process)(struct perf_file_section *section,
struct perf_header *h, int fd, void *data);
@@ -2295,7 +2326,7 @@ int perf_header__fprintf_info(struct perf_session *session, FILE *fp, bool full)
return 0;
}

-static int do_write_feat(int fd, struct perf_header *h, int type,
+static int do_write_feat(struct feat_fd *fd, struct perf_header *h, int type,
struct perf_file_section **p,
struct perf_evlist *evlist)
{
@@ -2306,18 +2337,22 @@ static int do_write_feat(int fd, struct perf_header *h, int type,
if (!feat_ops[type].write)
return -1;

- (*p)->offset = lseek(fd, 0, SEEK_CUR);
+ if (fd->buf) {
+ pr_err("do_write_feat to memory buffer\n");
+ return -1;
+ }
+ (*p)->offset = lseek(fd->fd, 0, SEEK_CUR);

- err = feat_ops[type].write(fd, h, evlist);
+ err = feat_ops[type].write(fd, evlist);
if (err < 0) {
pr_debug("failed to write feature %s\n", feat_ops[type].name);

/* undo anything written */
- lseek(fd, (*p)->offset, SEEK_SET);
+ lseek(fd->fd, (*p)->offset, SEEK_SET);

return -1;
}
- (*p)->size = lseek(fd, 0, SEEK_CUR) - (*p)->offset;
+ (*p)->size = lseek(fd->fd, 0, SEEK_CUR) - (*p)->offset;
(*p)++;
}
return ret;
@@ -2327,12 +2362,22 @@ static int perf_header__adds_write(struct perf_header *header,
struct perf_evlist *evlist, int fd)
{
int nr_sections;
+ struct feat_fd fdd;
struct perf_file_section *feat_sec, *p;
int sec_size;
u64 sec_start;
int feat;
int err;

+ /*
+ * may write more than needed due to dropped feature, but
+ * this is okay, reader will skip the mising entries
+ */
+ fdd = (struct feat_fd){
+ .fd = fd,
+ .ph = header,
+ };
+
nr_sections = bitmap_weight(header->adds_features, HEADER_FEAT_BITS);
if (!nr_sections)
return 0;
@@ -2347,7 +2392,7 @@ 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(fd, header, feat, &p, evlist))
+ if (do_write_feat(&fdd, header, feat, &p, evlist))
perf_header__clear_feat(header, feat);
}

@@ -2356,7 +2401,7 @@ static int perf_header__adds_write(struct perf_header *header,
* may write more than needed due to dropped feature, but
* this is okay, reader will skip the mising entries
*/
- err = do_write(fd, feat_sec, sec_size);
+ err = do_write(&fdd, feat_sec, sec_size);
if (err < 0)
pr_debug("failed to write feature section\n");
free(feat_sec);
@@ -2366,14 +2411,17 @@ static int perf_header__adds_write(struct perf_header *header,
int perf_header__write_pipe(int fd)
{
struct perf_pipe_file_header f_header;
+ struct feat_fd fdd;
int err;

+ fdd = (struct feat_fd){ .fd = fd };
+
f_header = (struct perf_pipe_file_header){
.magic = PERF_MAGIC,
.size = sizeof(f_header),
};

- err = do_write(fd, &f_header, sizeof(f_header));
+ err = do_write(&fdd, &f_header, sizeof(f_header));
if (err < 0) {
pr_debug("failed to write perf pipe header\n");
return err;
@@ -2390,21 +2438,23 @@ int perf_session__write_header(struct perf_session *session,
struct perf_file_attr f_attr;
struct perf_header *header = &session->header;
struct perf_evsel *evsel;
+ struct feat_fd fdd;
u64 attr_offset;
int err;

+ fdd = (struct feat_fd){ .fd = fd};
lseek(fd, sizeof(f_header), SEEK_SET);

evlist__for_each_entry(session->evlist, evsel) {
evsel->id_offset = lseek(fd, 0, SEEK_CUR);
- err = do_write(fd, evsel->id, evsel->ids * sizeof(u64));
+ err = do_write(&fdd, evsel->id, evsel->ids * sizeof(u64));
if (err < 0) {
pr_debug("failed to write perf header\n");
return err;
}
}

- attr_offset = lseek(fd, 0, SEEK_CUR);
+ attr_offset = lseek(fdd.fd, 0, SEEK_CUR);

evlist__for_each_entry(evlist, evsel) {
f_attr = (struct perf_file_attr){
@@ -2414,7 +2464,7 @@ int perf_session__write_header(struct perf_session *session,
.size = evsel->ids * sizeof(u64),
}
};
- err = do_write(fd, &f_attr, sizeof(f_attr));
+ err = do_write(&fdd, &f_attr, sizeof(f_attr));
if (err < 0) {
pr_debug("failed to write perf header attribute\n");
return err;
@@ -2449,7 +2499,7 @@ int perf_session__write_header(struct perf_session *session,
memcpy(&f_header.adds_features, &header->adds_features, sizeof(header->adds_features));

lseek(fd, 0, SEEK_SET);
- err = do_write(fd, &f_header, sizeof(f_header));
+ err = do_write(&fdd, &f_header, sizeof(f_header));
if (err < 0) {
pr_debug("failed to write perf header\n");
return err;
@@ -2724,6 +2774,10 @@ static int perf_file_header__read_pipe(struct perf_pipe_file_header *header,
struct perf_header *ph, int fd,
bool repipe)
{
+ struct feat_fd fdd = {
+ .fd = STDOUT_FILENO,
+ .ph = ph,
+ };
ssize_t ret;

ret = readn(fd, header, sizeof(*header));
@@ -2738,7 +2792,7 @@ static int perf_file_header__read_pipe(struct perf_pipe_file_header *header,
if (ph->needs_swap)
header->size = bswap_64(header->size);

- if (repipe && do_write(STDOUT_FILENO, header, sizeof(*header)) < 0)
+ if (repipe && do_write(&fdd, header, sizeof(*header)) < 0)
return -1;

return 0;
@@ -3246,6 +3300,7 @@ int perf_event__synthesize_tracing_data(struct perf_tool *tool, int fd,
union perf_event ev;
struct tracing_data *tdata;
ssize_t size = 0, aligned_size = 0, padding;
+ struct feat_fd fdd;
int err __maybe_unused = 0;

/*
@@ -3280,7 +3335,8 @@ int perf_event__synthesize_tracing_data(struct perf_tool *tool, int fd,
*/
tracing_data_put(tdata);

- if (write_padded(fd, NULL, 0, padding))
+ fdd = (struct feat_fd){ .fd = fd };
+ if (write_padded(&fdd, NULL, 0, padding))
return -1;

return aligned_size;
diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h
index d30109b421ee..9d8dcd5eb727 100644
--- a/tools/perf/util/header.h
+++ b/tools/perf/util/header.h
@@ -144,7 +144,12 @@ bool is_perf_magic(u64 magic);

#define NAME_ALIGN 64

-int write_padded(int fd, const void *bf, size_t count, size_t count_aligned);
+struct feat_fd;
+
+int do_write(struct feat_fd *fd, const void *buf, size_t size);
+
+int write_padded(struct feat_fd *fd, const void *bf,
+ size_t count, size_t count_aligned);

/*
* arch specific callback
--
2.13.0.303.g4ebf302169-goog

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