[PATCH v5 01/16] perf header: encapsulate read and swap

David Carrillo-Cisneros
2017-07-11T23:56:52Z

Most callers of readn in perf header read either a 32 or a 64 bits
number, error check it and swap it, if necessary.

Create do_read_u32 and do_read_u64 to simplify these use cases.

Signed-off-by: David Carrillo-Cisneros <davidcc@google.com>
---
tools/perf/util/header.c | 210 +++++++++++++++++------------------------------
1 file changed, 77 insertions(+), 133 deletions(-)

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 5cac8d5e009a..5492cd8d51a8 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -118,25 +118,54 @@ static int do_write_string(int fd, const char *str)
return write_padded(fd, str, olen, len);
}

+static int __do_read(int fd, void *addr, ssize_t size)
+{
+ ssize_t ret = readn(fd, addr, size);
+
+ if (ret != size)
+ return ret < 0 ? (int)ret : -1;
+ return 0;
+}
+
+static int do_read_u32(int fd, struct perf_header *ph, u32 *addr)
+{
+ int ret;
+
+ ret = __do_read(fd, addr, sizeof(*addr));
+ if (ret)
+ return ret;
+
+ if (ph->needs_swap)
+ *addr = bswap_32(*addr);
+ return 0;
+}
+
+static int do_read_u64(int fd, struct perf_header *ph, u64 *addr)
+{
+ int ret;
+
+ ret = __do_read(fd, addr, sizeof(*addr));
+ if (ret)
+ return ret;
+
+ if (ph->needs_swap)
+ *addr = bswap_64(*addr);
+ return 0;
+}
+
static char *do_read_string(int fd, struct perf_header *ph)
{
- 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, ph, &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
* thus the actual strlen of buf
@@ -1187,24 +1216,15 @@ read_event_desc(struct perf_header *ph, int fd)
u64 *id;
void *buf = NULL;
u32 nre, sz, nr, i, j;
- ssize_t ret;
size_t msz;

/* number of events */
- ret = readn(fd, &nre, sizeof(nre));
- if (ret != (ssize_t)sizeof(nre))
+ if (do_read_u32(fd, ph, &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, ph, &sz))
goto error;

- if (ph->needs_swap)
- sz = bswap_32(sz);
-
/* buffer to hold on file attr struct */
buf = malloc(sz);
if (!buf)
@@ -1226,8 +1246,7 @@ 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);
- if (ret != (ssize_t)sz)
+ if (__do_read(fd, buf, sz))
goto error;

if (ph->needs_swap)
@@ -1235,16 +1254,15 @@ read_event_desc(struct perf_header *ph, int fd)

memcpy(&evsel->attr, buf, msz);

- ret = readn(fd, &nr, sizeof(nr));
- if (ret != (ssize_t)sizeof(nr))
+ if (do_read_u32(fd, ph, &nr))
goto error;

- if (ph->needs_swap) {
- nr = bswap_32(nr);
+ if (ph->needs_swap)
evsel->needs_swap = true;
- }

evsel->name = do_read_string(fd, ph);
+ if (!evsel->name)
+ goto error;

if (!nr)
continue;
@@ -1256,11 +1274,8 @@ 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, ph, id))
goto error;
- if (ph->needs_swap)
- *id = bswap_64(*id);
id++;
}
}
@@ -1640,26 +1655,18 @@ static int process_nrcpus(struct perf_file_section *section __maybe_unused,
struct perf_header *ph, int 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, ph, &nr_cpus_avail);
+ if (ret)
+ return ret;

- ph->env.nr_cpus_online = nr;
+ ret = do_read_u32(fd, ph, &nr_cpus_online);
+ if (ret)
+ return ret;
+ ph->env.nr_cpus_avail = (int)nr_cpus_avail;
+ ph->env.nr_cpus_online = (int)nr_cpus_online;
return 0;
}

@@ -1683,17 +1690,13 @@ static int process_total_mem(struct perf_file_section *section __maybe_unused,
struct perf_header *ph, int 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, ph, &total_mem);
+ if (ret)
return -1;
-
- if (ph->needs_swap)
- mem = bswap_64(mem);
-
- ph->env.total_mem = mem;
+ ph->env.total_mem = (unsigned long long)total_mem;
return 0;
}

@@ -1753,17 +1756,12 @@ static int process_cmdline(struct perf_file_section *section,
struct perf_header *ph, int 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, ph, &nr))
return -1;

- if (ph->needs_swap)
- nr = bswap_32(nr);
-
ph->env.nr_cmdline = nr;

cmdline = zalloc(section->size + nr + 1);
@@ -1798,7 +1796,6 @@ static int process_cpu_topology(struct perf_file_section *section,
struct perf_header *ph, int fd,
void *data __maybe_unused)
{
- ssize_t ret;
u32 nr, i;
char *str;
struct strbuf sb;
@@ -1809,13 +1806,9 @@ static int process_cpu_topology(struct perf_file_section *section,
if (!ph->env.cpu)
return -1;

- ret = readn(fd, &nr, sizeof(nr));
- if (ret != sizeof(nr))
+ if (do_read_u32(fd, ph, &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)
@@ -1834,13 +1827,9 @@ static int process_cpu_topology(struct perf_file_section *section,
}
ph->env.sibling_cores = strbuf_detach(&sb, NULL);

- ret = readn(fd, &nr, sizeof(nr));
- if (ret != sizeof(nr))
+ if (do_read_u32(fd, ph, &nr))
return -1;

- if (ph->needs_swap)
- nr = bswap_32(nr);
-
ph->env.nr_sibling_threads = nr;
size += sizeof(u32);

@@ -1867,22 +1856,14 @@ static int process_cpu_topology(struct perf_file_section *section,
}

for (i = 0; i < (u32)cpu_nr; i++) {
- ret = readn(fd, &nr, sizeof(nr));
- if (ret != sizeof(nr))
+ if (do_read_u32(fd, ph, &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, ph, &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");
@@ -1906,18 +1887,13 @@ static int process_numa_topology(struct perf_file_section *section __maybe_unuse
void *data __maybe_unused)
{
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, ph, &nr))
return -1;

- if (ph->needs_swap)
- nr = bswap_32(nr);
-
nodes = zalloc(sizeof(*nodes) * nr);
if (!nodes)
return -ENOMEM;
@@ -1926,24 +1902,15 @@ 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, ph, &n->node))
goto error;

- ret = readn(fd, &n->mem_total, sizeof(u64));
- if (ret != sizeof(u64))
+ if (do_read_u64(fd, ph, &n->mem_total))
goto error;

- ret = readn(fd, &n->mem_free, sizeof(u64));
- if (ret != sizeof(u64))
+ if (do_read_u64(fd, ph, &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);
if (!str)
goto error;
@@ -1967,19 +1934,14 @@ static int process_pmu_mappings(struct perf_file_section *section __maybe_unused
struct perf_header *ph, int fd,
void *data __maybe_unused)
{
- ssize_t ret;
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, ph, &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;
@@ -1990,10 +1952,8 @@ 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, ph, &type))
goto error;
- if (ph->needs_swap)
- type = bswap_32(type);

name = do_read_string(fd, ph);
if (!name)
@@ -2033,12 +1993,9 @@ 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, ph, &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");
@@ -2054,16 +2011,11 @@ static int process_group_desc(struct perf_file_section *section __maybe_unused,
if (!desc[i].name)
goto out_free;

- if (readn(fd, &desc[i].leader_idx, sizeof(u32)) != sizeof(u32))
+ if (do_read_u32(fd, ph, &desc[i].leader_idx))
goto out_free;

- if (readn(fd, &desc[i].nr_members, sizeof(u32)) != sizeof(u32))
+ if (do_read_u32(fd, ph, &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);
- }
}

/*
@@ -2136,21 +2088,15 @@ static int process_cache(struct perf_file_section *section __maybe_unused,
struct cpu_cache_level *caches;
u32 cnt, i, version;

- if (readn(fd, &version, sizeof(version)) != sizeof(version))
+ if (do_read_u32(fd, ph, &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, ph, &cnt))
return -1;

- if (ph->needs_swap)
- cnt = bswap_32(cnt);
-
caches = zalloc(sizeof(*caches) * cnt);
if (!caches)
return -1;
@@ -2159,10 +2105,8 @@ 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, ph, &c.v))\
goto out_free_caches; \
- if (ph->needs_swap) \
- c.v = bswap_32(c.v); \

_R(level)
_R(line_size)
--
2.13.2.725.g09c95d1e9-goog