diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index d74b58d4105d..b2929d7a3d4e 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1103,118 +1103,80 @@ static int write_branch_stack(int fd __maybe_unused,
 	return 0;
 }
 
-static void print_hostname(struct perf_header *ph, int fd, FILE *fp)
+static void print_hostname(struct perf_header *ph, int fd __maybe_unused,
+			   FILE *fp)
 {
-	char *str = do_read_string(fd, ph);
-	fprintf(fp, "# hostname : %s\n", str);
-	free(str);
+	fprintf(fp, "# hostname : %s\n", ph->env.hostname);
 }
 
-static void print_osrelease(struct perf_header *ph, int fd, FILE *fp)
+static void print_osrelease(struct perf_header *ph, int fd __maybe_unused,
+			    FILE *fp)
 {
-	char *str = do_read_string(fd, ph);
-	fprintf(fp, "# os release : %s\n", str);
-	free(str);
+	fprintf(fp, "# os release : %s\n", ph->env.os_release);
 }
 
-static void print_arch(struct perf_header *ph, int fd, FILE *fp)
+static void print_arch(struct perf_header *ph, int fd __maybe_unused, FILE *fp)
 {
-	char *str = do_read_string(fd, ph);
-	fprintf(fp, "# arch : %s\n", str);
-	free(str);
+	fprintf(fp, "# arch : %s\n", ph->env.arch);
 }
 
-static void print_cpudesc(struct perf_header *ph, int fd, FILE *fp)
+static void print_cpudesc(struct perf_header *ph, int fd __maybe_unused,
+			  FILE *fp)
 {
-	char *str = do_read_string(fd, ph);
-	fprintf(fp, "# cpudesc : %s\n", str);
-	free(str);
+	fprintf(fp, "# cpudesc : %s\n", ph->env.cpu_desc);
 }
 
-static void print_nrcpus(struct perf_header *ph, int fd, FILE *fp)
+static void print_nrcpus(struct perf_header *ph, int fd __maybe_unused,
+			 FILE *fp)
 {
-	ssize_t ret;
-	u32 nr;
-
-	ret = read(fd, &nr, sizeof(nr));
-	if (ret != (ssize_t)sizeof(nr))
-		nr = -1; /* interpreted as error */
-
-	if (ph->needs_swap)
-		nr = bswap_32(nr);
-
-	fprintf(fp, "# nrcpus online : %u\n", nr);
-
-	ret = read(fd, &nr, sizeof(nr));
-	if (ret != (ssize_t)sizeof(nr))
-		nr = -1; /* interpreted as error */
-
-	if (ph->needs_swap)
-		nr = bswap_32(nr);
-
-	fprintf(fp, "# nrcpus avail : %u\n", nr);
+	fprintf(fp, "# nrcpus online : %u\n", ph->env.nr_cpus_online);
+	fprintf(fp, "# nrcpus avail : %u\n", ph->env.nr_cpus_avail);
 }
 
-static void print_version(struct perf_header *ph, int fd, FILE *fp)
+static void print_version(struct perf_header *ph, int fd __maybe_unused,
+			  FILE *fp)
 {
-	char *str = do_read_string(fd, ph);
-	fprintf(fp, "# perf version : %s\n", str);
-	free(str);
+	fprintf(fp, "# perf version : %s\n", ph->env.version);
 }
 
-static void print_cmdline(struct perf_header *ph, int fd, FILE *fp)
+static void print_cmdline(struct perf_header *ph, int fd __maybe_unused,
+			  FILE *fp)
 {
-	ssize_t ret;
+	int nr, i;
 	char *str;
-	u32 nr, i;
 
-	ret = read(fd, &nr, sizeof(nr));
-	if (ret != (ssize_t)sizeof(nr))
-		return;
-
-	if (ph->needs_swap)
-		nr = bswap_32(nr);
+	nr = ph->env.nr_cmdline;
+	str = ph->env.cmdline;
 
 	fprintf(fp, "# cmdline : ");
 
 	for (i = 0; i < nr; i++) {
-		str = do_read_string(fd, ph);
 		fprintf(fp, "%s ", str);
-		free(str);
+		str += strlen(str) + 1;
 	}
 	fputc('\n', fp);
 }
 
-static void print_cpu_topology(struct perf_header *ph, int fd, FILE *fp)
+static void print_cpu_topology(struct perf_header *ph, int fd __maybe_unused,
+			       FILE *fp)
 {
-	ssize_t ret;
-	u32 nr, i;
+	int nr, i;
 	char *str;
 
-	ret = read(fd, &nr, sizeof(nr));
-	if (ret != (ssize_t)sizeof(nr))
-		return;
-
-	if (ph->needs_swap)
-		nr = bswap_32(nr);
+	nr = ph->env.nr_sibling_cores;
+	str = ph->env.sibling_cores;
 
 	for (i = 0; i < nr; i++) {
-		str = do_read_string(fd, ph);
 		fprintf(fp, "# sibling cores   : %s\n", str);
-		free(str);
+		str += strlen(str) + 1;
 	}
 
-	ret = read(fd, &nr, sizeof(nr));
-	if (ret != (ssize_t)sizeof(nr))
-		return;
-
-	if (ph->needs_swap)
-		nr = bswap_32(nr);
+	nr = ph->env.nr_sibling_threads;
+	str = ph->env.sibling_threads;
 
 	for (i = 0; i < nr; i++) {
-		str = do_read_string(fd, ph);
 		fprintf(fp, "# sibling threads : %s\n", str);
-		free(str);
+		str += strlen(str) + 1;
 	}
 }
 
@@ -1375,126 +1337,89 @@ static void print_event_desc(struct perf_header *ph, int fd, FILE *fp)
 	free_event_desc(events);
 }
 
-static void print_total_mem(struct perf_header *h __maybe_unused, int fd,
+static void print_total_mem(struct perf_header *ph, int fd __maybe_unused,
 			    FILE *fp)
 {
-	uint64_t mem;
-	ssize_t ret;
-
-	ret = read(fd, &mem, sizeof(mem));
-	if (ret != sizeof(mem))
-		goto error;
-
-	if (h->needs_swap)
-		mem = bswap_64(mem);
-
-	fprintf(fp, "# total memory : %"PRIu64" kB\n", mem);
-	return;
-error:
-	fprintf(fp, "# total memory : unknown\n");
+	fprintf(fp, "# total memory : %Lu kB\n", ph->env.total_mem);
 }
 
-static void print_numa_topology(struct perf_header *h __maybe_unused, int fd,
+static void print_numa_topology(struct perf_header *ph, int fd __maybe_unused,
 				FILE *fp)
 {
-	ssize_t ret;
 	u32 nr, c, i;
-	char *str;
+	char *str, *tmp;
 	uint64_t mem_total, mem_free;
 
 	/* nr nodes */
-	ret = read(fd, &nr, sizeof(nr));
-	if (ret != (ssize_t)sizeof(nr))
-		goto error;
-
-	if (h->needs_swap)
-		nr = bswap_32(nr);
+	nr = ph->env.nr_numa_nodes;
+	str = ph->env.numa_nodes;
 
 	for (i = 0; i < nr; i++) {
-
 		/* node number */
-		ret = read(fd, &c, sizeof(c));
-		if (ret != (ssize_t)sizeof(c))
+		c = strtoul(str, &tmp, 0);
+		if (*tmp != ':')
 			goto error;
 
-		if (h->needs_swap)
-			c = bswap_32(c);
-
-		ret = read(fd, &mem_total, sizeof(u64));
-		if (ret != sizeof(u64))
+		str = tmp + 1;
+		mem_total = strtoull(str, &tmp, 0);
+		if (*tmp != ':')
 			goto error;
 
-		ret = read(fd, &mem_free, sizeof(u64));
-		if (ret != sizeof(u64))
+		str = tmp + 1;
+		mem_free = strtoull(str, &tmp, 0);
+		if (*tmp != ':')
 			goto error;
 
-		if (h->needs_swap) {
-			mem_total = bswap_64(mem_total);
-			mem_free = bswap_64(mem_free);
-		}
-
 		fprintf(fp, "# node%u meminfo  : total = %"PRIu64" kB,"
 			    " free = %"PRIu64" kB\n",
-			c,
-			mem_total,
-			mem_free);
+			c, mem_total, mem_free);
 
-		str = do_read_string(fd, h);
+		str = tmp + 1;
 		fprintf(fp, "# node%u cpu list : %s\n", c, str);
-		free(str);
 	}
 	return;
 error:
 	fprintf(fp, "# numa topology : not available\n");
 }
 
-static void print_cpuid(struct perf_header *ph, int fd, FILE *fp)
+static void print_cpuid(struct perf_header *ph, int fd __maybe_unused, FILE *fp)
 {
-	char *str = do_read_string(fd, ph);
-	fprintf(fp, "# cpuid : %s\n", str);
-	free(str);
+	fprintf(fp, "# cpuid : %s\n", ph->env.cpuid);
 }
 
 static void print_branch_stack(struct perf_header *ph __maybe_unused,
-			       int fd __maybe_unused,
-			       FILE *fp)
+			       int fd __maybe_unused, FILE *fp)
 {
 	fprintf(fp, "# contains samples with branch stack\n");
 }
 
-static void print_pmu_mappings(struct perf_header *ph, int fd, FILE *fp)
+static void print_pmu_mappings(struct perf_header *ph, int fd __maybe_unused,
+			       FILE *fp)
 {
 	const char *delimiter = "# pmu mappings: ";
-	char *name;
-	int ret;
+	char *str, *tmp;
 	u32 pmu_num;
 	u32 type;
 
-	ret = read(fd, &pmu_num, sizeof(pmu_num));
-	if (ret != sizeof(pmu_num))
-		goto error;
-
-	if (ph->needs_swap)
-		pmu_num = bswap_32(pmu_num);
-
+	pmu_num = ph->env.nr_pmu_mappings;
 	if (!pmu_num) {
 		fprintf(fp, "# pmu mappings: not available\n");
 		return;
 	}
 
-	while (pmu_num) {
-		if (read(fd, &type, sizeof(type)) != sizeof(type))
-			break;
-		if (ph->needs_swap)
-			type = bswap_32(type);
+	str = ph->env.pmu_mappings;
+
+	while (pmu_num) {
+		type = strtoul(str, &tmp, 0);
+		if (*tmp != ':')
+			goto error;
+
+		str = tmp + 1;
+		fprintf(fp, "%s%s = %" PRIu32, delimiter, str, type);
 
-		name = do_read_string(fd, ph);
-		if (!name)
-			break;
-		pmu_num--;
-		fprintf(fp, "%s%s = %" PRIu32, delimiter, name, type);
-		free(name);
 		delimiter = ", ";
+		str += strlen(str) + 1;
+		pmu_num--;
 	}
 
 	fprintf(fp, "\n");