[PATCH 5/7] perf header: use struct feat_fd for process and read

[David Carrillo-Cisneros <davidcc@google.com>]

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

To reduce the boiler plate, define and use the FEAT_PROCESS_STR_FUN
macro for the common case of header records that are a simple string.

Signed-off-by: David Carrillo-Cisneros <davidcc@google.com>
---
 tools/perf/util/header.c | 405 ++++++++++++++++++-----------------------------
 tools/perf/util/header.h |   1 +
 2 files changed, 156 insertions(+), 250 deletions(-)

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index e28770d12c1c..981f5e9685e2 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -141,27 +141,67 @@ static int do_write_string(struct feat_fd *fd, const char *str)
 	return write_padded(fd, str, olen, len);
 }
 
-static char *do_read_string(int fd, struct perf_header *ph)
+static int __do_read(struct feat_fd *fd, void *addr, ssize_t size)
+{
+	if (!fd->buf) {
+		ssize_t ret = readn(fd->fd, addr, size);
+
+		if (ret != (ssize_t)size)
+			return ret < 0 ? (int)ret : -1;
+		return 0;
+	}
+
+	assert((ssize_t)fd->size > fd->offset);
+	if (size > (ssize_t)fd->size - fd->offset)
+		return -1;
+
+	memcpy(addr, fd->buf + fd->offset, size);
+	fd->offset += size;
+
+	return 0;
+}
+
+static int do_read_u32(struct feat_fd *fd, u32 *addr)
+{
+	int ret;
+
+	ret = __do_read(fd, addr, sizeof(*addr));
+	if (ret)
+		return ret;
+
+	if (fd->ph->needs_swap)
+		*addr = bswap_32(*addr);
+	return 0;
+}
+
+static int do_read_u64(struct feat_fd *fd, u64 *addr)
+{
+	int ret;
+
+	ret = __do_read(fd, addr, sizeof(*addr));
+	if (ret)
+		return ret;
+
+	if (fd->ph->needs_swap)
+		*addr = bswap_64(*addr);
+	return 0;
+}
+
+static char *do_read_string(struct feat_fd *fd)
 {
-	ssize_t sz, ret;
 	u32 len;
 	char *buf;
 
-	sz = readn(fd, &len, sizeof(len));
-	if (sz < (ssize_t)sizeof(len))
+	if (do_read_u32(fd, &len))
 		return NULL;
 
-	if (ph->needs_swap)
-		len = bswap_32(len);
-
 	buf = malloc(len);
 	if (!buf)
 		return NULL;
 
-	ret = readn(fd, buf, len);
-	if (ret == (ssize_t)len) {
+	if (!__do_read(fd, buf, len)) {
 		/*
-		 * strings are padded by zeroes
+		 * note that strings are padded by zeroes
 		 * thus the actual strlen of buf
 		 * may be less than len
 		 */
@@ -1207,8 +1247,7 @@ static void free_event_desc(struct perf_evsel *events)
 	free(events);
 }
 
-static struct perf_evsel *
-read_event_desc(struct perf_header *ph, int fd)
+static struct perf_evsel *read_event_desc(struct feat_fd *fd)
 {
 	struct perf_evsel *evsel, *events = NULL;
 	u64 *id;
@@ -1218,20 +1257,12 @@ read_event_desc(struct perf_header *ph, int fd)
 	size_t msz;
 
 	/* number of events */
-	ret = readn(fd, &nre, sizeof(nre));
-	if (ret != (ssize_t)sizeof(nre))
+	if (do_read_u32(fd, &nre))
 		goto error;
 
-	if (ph->needs_swap)
-		nre = bswap_32(nre);
-
-	ret = readn(fd, &sz, sizeof(sz));
-	if (ret != (ssize_t)sizeof(sz))
+	if (do_read_u32(fd, &sz))
 		goto error;
 
-	if (ph->needs_swap)
-		sz = bswap_32(sz);
-
 	/* buffer to hold on file attr struct */
 	buf = malloc(sz);
 	if (!buf)
@@ -1253,25 +1284,22 @@ read_event_desc(struct perf_header *ph, int fd)
 		 * must read entire on-file attr struct to
 		 * sync up with layout.
 		 */
-		ret = readn(fd, buf, sz);
+		ret = __do_read(fd, buf, sz);
 		if (ret != (ssize_t)sz)
 			goto error;
 
-		if (ph->needs_swap)
+		if (fd->ph->needs_swap)
 			perf_event__attr_swap(buf);
 
 		memcpy(&evsel->attr, buf, msz);
 
-		ret = readn(fd, &nr, sizeof(nr));
-		if (ret != (ssize_t)sizeof(nr))
+		if (do_read_u32(fd, &nr))
 			goto error;
 
-		if (ph->needs_swap) {
-			nr = bswap_32(nr);
+		if (fd->ph->needs_swap)
 			evsel->needs_swap = true;
-		}
 
-		evsel->name = do_read_string(fd, ph);
+		evsel->name = do_read_string(fd);
 
 		if (!nr)
 			continue;
@@ -1283,11 +1311,8 @@ read_event_desc(struct perf_header *ph, int fd)
 		evsel->id = id;
 
 		for (j = 0 ; j < nr; j++) {
-			ret = readn(fd, id, sizeof(*id));
-			if (ret != (ssize_t)sizeof(*id))
+			if (do_read_u64(fd, id))
 				goto error;
-			if (ph->needs_swap)
-				*id = bswap_64(*id);
 			id++;
 		}
 	}
@@ -1308,7 +1333,7 @@ static int __desc_attr__fprintf(FILE *fp, const char *name, const char *val,
 
 static void print_event_desc(struct feat_fd *fd, FILE *fp)
 {
-	struct perf_evsel *evsel, *events = read_event_desc(fd->ph, fd->fd);
+	struct perf_evsel *evsel, *events = read_event_desc(fd);
 	u32 j;
 	u64 *id;
 
@@ -1598,113 +1623,61 @@ static int perf_header__read_build_ids(struct perf_header *header,
 	return err;
 }
 
-static int process_tracing_data(struct perf_file_section *section __maybe_unused,
-				struct perf_header *ph __maybe_unused,
-				int fd, void *data)
-{
-	ssize_t ret = trace_report(fd, data, false);
-	return ret < 0 ? -1 : 0;
+/* Macro for features that simply need to read and store a string. */
+#define FEAT_PROCESS_STR_FUN(__feat, __feat_env) \
+static int process_##__feat(struct feat_fd *fd, void *data __maybe_unused) \
+{\
+	fd->ph->env.__feat_env = do_read_string(fd); \
+	return fd->ph->env.__feat_env ? 0 : -ENOMEM; \
 }
 
-static int process_build_id(struct perf_file_section *section,
-			    struct perf_header *ph, int fd,
-			    void *data __maybe_unused)
+FEAT_PROCESS_STR_FUN(hostname, hostname);
+FEAT_PROCESS_STR_FUN(osrelease, os_release);
+FEAT_PROCESS_STR_FUN(version, version);
+FEAT_PROCESS_STR_FUN(arch, arch);
+FEAT_PROCESS_STR_FUN(cpudesc, cpu_desc);
+FEAT_PROCESS_STR_FUN(cpuid, cpuid);
+
+static int process_build_id(struct feat_fd *fd, void *data __maybe_unused)
 {
-	if (perf_header__read_build_ids(ph, fd, section->offset, section->size))
+	if (perf_header__read_build_ids(fd->ph, fd->fd, fd->offset, fd->size))
 		pr_debug("Failed to read buildids, continuing...\n");
 	return 0;
 }
 
-static int process_hostname(struct perf_file_section *section __maybe_unused,
-			    struct perf_header *ph, int fd,
-			    void *data __maybe_unused)
-{
-	ph->env.hostname = do_read_string(fd, ph);
-	return ph->env.hostname ? 0 : -ENOMEM;
-}
-
-static int process_osrelease(struct perf_file_section *section __maybe_unused,
-			     struct perf_header *ph, int fd,
-			     void *data __maybe_unused)
-{
-	ph->env.os_release = do_read_string(fd, ph);
-	return ph->env.os_release ? 0 : -ENOMEM;
-}
-
-static int process_version(struct perf_file_section *section __maybe_unused,
-			   struct perf_header *ph, int fd,
-			   void *data __maybe_unused)
+static int process_tracing_data(struct feat_fd *fd, void *data)
 {
-	ph->env.version = do_read_string(fd, ph);
-	return ph->env.version ? 0 : -ENOMEM;
-}
+	ssize_t ret = trace_report(fd->fd, data, false);
 
-static int process_arch(struct perf_file_section *section __maybe_unused,
-			struct perf_header *ph,	int fd,
-			void *data __maybe_unused)
-{
-	ph->env.arch = do_read_string(fd, ph);
-	return ph->env.arch ? 0 : -ENOMEM;
+	return ret < 0 ? -1 : 0;
 }
 
-static int process_nrcpus(struct perf_file_section *section __maybe_unused,
-			  struct perf_header *ph, int fd,
-			  void *data __maybe_unused)
+static int process_nrcpus(struct feat_fd *fd, void *data __maybe_unused)
 {
-	ssize_t ret;
-	u32 nr;
-
-	ret = readn(fd, &nr, sizeof(nr));
-	if (ret != sizeof(nr))
-		return -1;
-
-	if (ph->needs_swap)
-		nr = bswap_32(nr);
-
-	ph->env.nr_cpus_avail = nr;
-
-	ret = readn(fd, &nr, sizeof(nr));
-	if (ret != sizeof(nr))
-		return -1;
+	int ret;
+	u32 nr_cpus_avail, nr_cpus_online;
 
-	if (ph->needs_swap)
-		nr = bswap_32(nr);
+	ret = do_read_u32(fd, &nr_cpus_avail);
+	if (ret)
+		return ret;
 
-	ph->env.nr_cpus_online = nr;
+	ret = do_read_u32(fd, &nr_cpus_online);
+	if (ret)
+		return ret;
+	fd->ph->env.nr_cpus_avail = (int)nr_cpus_avail;
+	fd->ph->env.nr_cpus_online = (int)nr_cpus_online;
 	return 0;
 }
 
-static int process_cpudesc(struct perf_file_section *section __maybe_unused,
-			   struct perf_header *ph, int fd,
-			   void *data __maybe_unused)
-{
-	ph->env.cpu_desc = do_read_string(fd, ph);
-	return ph->env.cpu_desc ? 0 : -ENOMEM;
-}
-
-static int process_cpuid(struct perf_file_section *section __maybe_unused,
-			 struct perf_header *ph,  int fd,
-			 void *data __maybe_unused)
-{
-	ph->env.cpuid = do_read_string(fd, ph);
-	return ph->env.cpuid ? 0 : -ENOMEM;
-}
-
-static int process_total_mem(struct perf_file_section *section __maybe_unused,
-			     struct perf_header *ph, int fd,
-			     void *data __maybe_unused)
+static int process_total_mem(struct feat_fd *fd, void *data __maybe_unused)
 {
-	uint64_t mem;
-	ssize_t ret;
+	u64 total_mem;
+	int ret;
 
-	ret = readn(fd, &mem, sizeof(mem));
-	if (ret != sizeof(mem))
+	ret = do_read_u64(fd, &total_mem);
+	if (ret)
 		return -1;
-
-	if (ph->needs_swap)
-		mem = bswap_64(mem);
-
-	ph->env.total_mem = mem;
+	fd->ph->env.total_mem = (unsigned long long)total_mem;
 	return 0;
 }
 
@@ -1741,17 +1714,15 @@ perf_evlist__set_event_name(struct perf_evlist *evlist,
 }
 
 static int
-process_event_desc(struct perf_file_section *section __maybe_unused,
-		   struct perf_header *header, int fd,
-		   void *data __maybe_unused)
+process_event_desc(struct feat_fd *fd, void *data __maybe_unused)
 {
 	struct perf_session *session;
-	struct perf_evsel *evsel, *events = read_event_desc(header, fd);
+	struct perf_evsel *evsel, *events = read_event_desc(fd);
 
 	if (!events)
 		return 0;
 
-	session = container_of(header, struct perf_session, header);
+	session = container_of(fd->ph, struct perf_session, header);
 	for (evsel = events; evsel->attr.size; evsel++)
 		perf_evlist__set_event_name(session->evlist, evsel);
 
@@ -1760,24 +1731,17 @@ process_event_desc(struct perf_file_section *section __maybe_unused,
 	return 0;
 }
 
-static int process_cmdline(struct perf_file_section *section,
-			   struct perf_header *ph, int fd,
-			   void *data __maybe_unused)
+static int process_cmdline(struct feat_fd *fd, void *data __maybe_unused)
 {
-	ssize_t ret;
 	char *str, *cmdline = NULL, **argv = NULL;
 	u32 nr, i, len = 0;
 
-	ret = readn(fd, &nr, sizeof(nr));
-	if (ret != sizeof(nr))
+	if (do_read_u32(fd, &nr))
 		return -1;
 
-	if (ph->needs_swap)
-		nr = bswap_32(nr);
-
-	ph->env.nr_cmdline = nr;
+	fd->ph->env.nr_cmdline = nr;
 
-	cmdline = zalloc(section->size + nr + 1);
+	cmdline = zalloc(fd->size + nr + 1);
 	if (!cmdline)
 		return -1;
 
@@ -1786,7 +1750,7 @@ static int process_cmdline(struct perf_file_section *section,
 		goto error;
 
 	for (i = 0; i < nr; i++) {
-		str = do_read_string(fd, ph);
+		str = do_read_string(fd);
 		if (!str)
 			goto error;
 
@@ -1795,8 +1759,8 @@ static int process_cmdline(struct perf_file_section *section,
 		len += strlen(str) + 1;
 		free(str);
 	}
-	ph->env.cmdline = cmdline;
-	ph->env.cmdline_argv = (const char **) argv;
+	fd->ph->env.cmdline = cmdline;
+	fd->ph->env.cmdline_argv = (const char **) argv;
 	return 0;
 
 error:
@@ -1805,65 +1769,51 @@ static int process_cmdline(struct perf_file_section *section,
 	return -1;
 }
 
-static int process_cpu_topology(struct perf_file_section *section,
-				struct perf_header *ph, int fd,
-				void *data __maybe_unused)
+static int process_cpu_topology(struct feat_fd *fd, void *data __maybe_unused)
 {
-	ssize_t ret;
 	u32 nr, i;
 	char *str;
 	struct strbuf sb;
-	int cpu_nr = ph->env.nr_cpus_avail;
-	u64 size = 0;
+	int cpu_nr = fd->ph->env.nr_cpus_avail;
+	struct perf_header *ph = fd->ph;
+	u64 start_offset = fd->offset;
 
 	ph->env.cpu = calloc(cpu_nr, sizeof(*ph->env.cpu));
 	if (!ph->env.cpu)
 		return -1;
 
-	ret = readn(fd, &nr, sizeof(nr));
-	if (ret != sizeof(nr))
+	if (do_read_u32(fd, &nr))
 		goto free_cpu;
 
-	if (ph->needs_swap)
-		nr = bswap_32(nr);
-
 	ph->env.nr_sibling_cores = nr;
-	size += sizeof(u32);
 	if (strbuf_init(&sb, 128) < 0)
 		goto free_cpu;
 
 	for (i = 0; i < nr; i++) {
-		str = do_read_string(fd, ph);
+		str = do_read_string(fd);
 		if (!str)
 			goto error;
 
 		/* include a NULL character at the end */
 		if (strbuf_add(&sb, str, strlen(str) + 1) < 0)
 			goto error;
-		size += string_size(str);
 		free(str);
 	}
 	ph->env.sibling_cores = strbuf_detach(&sb, NULL);
 
-	ret = readn(fd, &nr, sizeof(nr));
-	if (ret != sizeof(nr))
+	if (do_read_u32(fd, &nr))
 		return -1;
 
-	if (ph->needs_swap)
-		nr = bswap_32(nr);
-
 	ph->env.nr_sibling_threads = nr;
-	size += sizeof(u32);
 
 	for (i = 0; i < nr; i++) {
-		str = do_read_string(fd, ph);
+		str = do_read_string(fd);
 		if (!str)
 			goto error;
 
 		/* include a NULL character at the end */
 		if (strbuf_add(&sb, str, strlen(str) + 1) < 0)
 			goto error;
-		size += string_size(str);
 		free(str);
 	}
 	ph->env.sibling_threads = strbuf_detach(&sb, NULL);
@@ -1872,28 +1822,20 @@ static int process_cpu_topology(struct perf_file_section *section,
 	 * The header may be from old perf,
 	 * which doesn't include core id and socket id information.
 	 */
-	if (section->size <= size) {
+	if (fd->size <= fd->offset - start_offset) {
 		zfree(&ph->env.cpu);
 		return 0;
 	}
 
 	for (i = 0; i < (u32)cpu_nr; i++) {
-		ret = readn(fd, &nr, sizeof(nr));
-		if (ret != sizeof(nr))
+		if (do_read_u32(fd, &nr))
 			goto free_cpu;
 
-		if (ph->needs_swap)
-			nr = bswap_32(nr);
-
 		ph->env.cpu[i].core_id = nr;
 
-		ret = readn(fd, &nr, sizeof(nr));
-		if (ret != sizeof(nr))
+		if (do_read_u32(fd, &nr))
 			goto free_cpu;
 
-		if (ph->needs_swap)
-			nr = bswap_32(nr);
-
 		if (nr != (u32)-1 && nr > (u32)cpu_nr) {
 			pr_debug("socket_id number is too big."
 				 "You may need to upgrade the perf tool.\n");
@@ -1912,23 +1854,17 @@ static int process_cpu_topology(struct perf_file_section *section,
 	return -1;
 }
 
-static int process_numa_topology(struct perf_file_section *section __maybe_unused,
-				 struct perf_header *ph, int fd,
-				 void *data __maybe_unused)
+static int process_numa_topology(struct feat_fd *fd, void *data __maybe_unused)
 {
+	struct perf_header *ph = fd->ph;
 	struct numa_node *nodes, *n;
-	ssize_t ret;
 	u32 nr, i;
 	char *str;
 
 	/* nr nodes */
-	ret = readn(fd, &nr, sizeof(nr));
-	if (ret != sizeof(nr))
+	if (do_read_u32(fd, &nr))
 		return -1;
 
-	if (ph->needs_swap)
-		nr = bswap_32(nr);
-
 	nodes = zalloc(sizeof(*nodes) * nr);
 	if (!nodes)
 		return -ENOMEM;
@@ -1937,25 +1873,16 @@ static int process_numa_topology(struct perf_file_section *section __maybe_unuse
 		n = &nodes[i];
 
 		/* node number */
-		ret = readn(fd, &n->node, sizeof(u32));
-		if (ret != sizeof(n->node))
+		if (do_read_u32(fd, &n->node))
 			goto error;
 
-		ret = readn(fd, &n->mem_total, sizeof(u64));
-		if (ret != sizeof(u64))
+		if (do_read_u64(fd, &n->mem_total))
 			goto error;
 
-		ret = readn(fd, &n->mem_free, sizeof(u64));
-		if (ret != sizeof(u64))
+		if (do_read_u64(fd, &n->mem_free))
 			goto error;
 
-		if (ph->needs_swap) {
-			n->node      = bswap_32(n->node);
-			n->mem_total = bswap_64(n->mem_total);
-			n->mem_free  = bswap_64(n->mem_free);
-		}
-
-		str = do_read_string(fd, ph);
+		str = do_read_string(fd);
 		if (!str)
 			goto error;
 
@@ -1974,23 +1901,17 @@ static int process_numa_topology(struct perf_file_section *section __maybe_unuse
 	return -1;
 }
 
-static int process_pmu_mappings(struct perf_file_section *section __maybe_unused,
-				struct perf_header *ph, int fd,
-				void *data __maybe_unused)
+static int process_pmu_mappings(struct feat_fd *fd, void *data __maybe_unused)
 {
-	ssize_t ret;
+	struct perf_header *ph = fd->ph;
 	char *name;
 	u32 pmu_num;
 	u32 type;
 	struct strbuf sb;
 
-	ret = readn(fd, &pmu_num, sizeof(pmu_num));
-	if (ret != sizeof(pmu_num))
+	if (do_read_u32(fd, &pmu_num))
 		return -1;
 
-	if (ph->needs_swap)
-		pmu_num = bswap_32(pmu_num);
-
 	if (!pmu_num) {
 		pr_debug("pmu mappings not available\n");
 		return 0;
@@ -2001,12 +1922,10 @@ static int process_pmu_mappings(struct perf_file_section *section __maybe_unused
 		return -1;
 
 	while (pmu_num) {
-		if (readn(fd, &type, sizeof(type)) != sizeof(type))
+		if (do_read_u32(fd, &type))
 			goto error;
-		if (ph->needs_swap)
-			type = bswap_32(type);
 
-		name = do_read_string(fd, ph);
+		name = do_read_string(fd);
 		if (!name)
 			goto error;
 
@@ -2030,10 +1949,9 @@ static int process_pmu_mappings(struct perf_file_section *section __maybe_unused
 	return -1;
 }
 
-static int process_group_desc(struct perf_file_section *section __maybe_unused,
-			      struct perf_header *ph, int fd,
-			      void *data __maybe_unused)
+static int process_group_desc(struct feat_fd *fd, void *data __maybe_unused)
 {
+	struct perf_header *ph = fd->ph;
 	size_t ret = -1;
 	u32 i, nr, nr_groups;
 	struct perf_session *session;
@@ -2044,12 +1962,9 @@ static int process_group_desc(struct perf_file_section *section __maybe_unused,
 		u32 nr_members;
 	} *desc;
 
-	if (readn(fd, &nr_groups, sizeof(nr_groups)) != sizeof(nr_groups))
+	if (do_read_u32(fd, &nr_groups))
 		return -1;
 
-	if (ph->needs_swap)
-		nr_groups = bswap_32(nr_groups);
-
 	ph->env.nr_groups = nr_groups;
 	if (!nr_groups) {
 		pr_debug("group desc not available\n");
@@ -2061,20 +1976,15 @@ static int process_group_desc(struct perf_file_section *section __maybe_unused,
 		return -1;
 
 	for (i = 0; i < nr_groups; i++) {
-		desc[i].name = do_read_string(fd, ph);
+		desc[i].name = do_read_string(fd);
 		if (!desc[i].name)
 			goto out_free;
 
-		if (readn(fd, &desc[i].leader_idx, sizeof(u32)) != sizeof(u32))
+		if (do_read_u32(fd, &desc[i].leader_idx))
 			goto out_free;
 
-		if (readn(fd, &desc[i].nr_members, sizeof(u32)) != sizeof(u32))
+		if (do_read_u32(fd, &desc[i].nr_members))
 			goto out_free;
-
-		if (ph->needs_swap) {
-			desc[i].leader_idx = bswap_32(desc[i].leader_idx);
-			desc[i].nr_members = bswap_32(desc[i].nr_members);
-		}
 	}
 
 	/*
@@ -2124,44 +2034,35 @@ static int process_group_desc(struct perf_file_section *section __maybe_unused,
 	return ret;
 }
 
-static int process_auxtrace(struct perf_file_section *section,
-			    struct perf_header *ph, int fd,
-			    void *data __maybe_unused)
+static int process_auxtrace(struct feat_fd *fd, void *data __maybe_unused)
 {
 	struct perf_session *session;
 	int err;
 
-	session = container_of(ph, struct perf_session, header);
+	session = container_of(fd->ph, struct perf_session, header);
 
-	err = auxtrace_index__process(fd, section->size, session,
-				      ph->needs_swap);
+	err = auxtrace_index__process(fd->fd, fd->size, session,
+				      fd->ph->needs_swap);
 	if (err < 0)
 		pr_err("Failed to process auxtrace index\n");
 	return err;
 }
 
-static int process_cache(struct perf_file_section *section __maybe_unused,
-			 struct perf_header *ph __maybe_unused, int fd __maybe_unused,
-			 void *data __maybe_unused)
+static int process_cache(struct feat_fd *fd, void *data __maybe_unused)
 {
 	struct cpu_cache_level *caches;
 	u32 cnt, i, version;
 
-	if (readn(fd, &version, sizeof(version)) != sizeof(version))
+	pr_err("process_cache\n");
+	if (do_read_u32(fd, &version))
 		return -1;
 
-	if (ph->needs_swap)
-		version = bswap_32(version);
-
 	if (version != 1)
 		return -1;
 
-	if (readn(fd, &cnt, sizeof(cnt)) != sizeof(cnt))
+	if (do_read_u32(fd, &cnt))
 		return -1;
 
-	if (ph->needs_swap)
-		cnt = bswap_32(cnt);
-
 	caches = zalloc(sizeof(*caches) * cnt);
 	if (!caches)
 		return -1;
@@ -2170,10 +2071,8 @@ static int process_cache(struct perf_file_section *section __maybe_unused,
 		struct cpu_cache_level c;
 
 		#define _R(v)						\
-			if (readn(fd, &c.v, sizeof(u32)) != sizeof(u32))\
+			if (do_read_u32(fd, &c.v))\
 				goto out_free_caches;			\
-			if (ph->needs_swap)				\
-				c.v = bswap_32(c.v);			\
 
 		_R(level)
 		_R(line_size)
@@ -2182,7 +2081,7 @@ static int process_cache(struct perf_file_section *section __maybe_unused,
 		#undef _R
 
 		#define _R(v)				\
-			c.v = do_read_string(fd, ph);	\
+			c.v = do_read_string(fd);	\
 			if (!c.v)			\
 				goto out_free_caches;
 
@@ -2194,8 +2093,8 @@ static int process_cache(struct perf_file_section *section __maybe_unused,
 		caches[i] = c;
 	}
 
-	ph->env.caches = caches;
-	ph->env.caches_cnt = cnt;
+	fd->ph->env.caches = caches;
+	fd->ph->env.caches_cnt = cnt;
 	return 0;
 out_free_caches:
 	free(caches);
@@ -2205,8 +2104,7 @@ static int process_cache(struct perf_file_section *section __maybe_unused,
 struct feature_ops {
 	int (*write)(struct feat_fd *fd, struct perf_evlist *evlist);
 	void (*print)(struct feat_fd *fd, FILE *fp);
-	int (*process)(struct perf_file_section *section,
-		       struct perf_header *h, int fd, void *data);
+	int (*process)(struct feat_fd *fd, void *data);
 	const char *name;
 	bool full_only;
 };
@@ -2747,6 +2645,13 @@ static int perf_file_section__process(struct perf_file_section *section,
 				      struct perf_header *ph,
 				      int feat, int fd, void *data)
 {
+	struct feat_fd fdd = {
+		.fd = fd,
+		.ph = ph,
+		.size = section->size,
+		.offset = section->offset,
+	};
+
 	if (lseek(fd, section->offset, SEEK_SET) == (off_t)-1) {
 		pr_debug("Failed to lseek to %" PRIu64 " offset for feature "
 			  "%d, continuing...\n", section->offset, feat);
@@ -2761,7 +2666,7 @@ static int perf_file_section__process(struct perf_file_section *section,
 	if (!feat_ops[feat].process)
 		return 0;
 
-	return feat_ops[feat].process(section, ph, fd, data);
+	return feat_ops[feat].process(&fdd, data);
 }
 
 static int perf_file_header__read_pipe(struct perf_pipe_file_header *header,
diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h
index 9d8dcd5eb727..86ab723cbee4 100644
--- a/tools/perf/util/header.h
+++ b/tools/perf/util/header.h
@@ -78,6 +78,7 @@ struct perf_header {
 	struct perf_env 	env;
 };
 
+struct feat_fd;
 struct perf_evlist;
 struct perf_session;
 
-- 
2.13.0.303.g4ebf302169-goog