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Subject[PATCH 07/14] perf tools: Add file size check and factor dso__data_read_offset
Date
Adding file size check, because the lseek will succeed
for any offset behind file size. Factoring the code
the check the offset earli in the flow.

Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jean Pihet <jean.pihet@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
tools/perf/util/dso.c | 78 ++++++++++++++++++++++++++++++++++++++-------------
tools/perf/util/dso.h | 1 +
2 files changed, 59 insertions(+), 20 deletions(-)

diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 316e087..ad0e2da 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -197,6 +197,7 @@ static void close_data_fd(struct dso *dso)
if (dso->data.fd >= 0) {
close(dso->data.fd);
dso->data.fd = -1;
+ dso->data.file_size = 0;
dso__list_del(dso);
}
}
@@ -366,17 +367,10 @@ dso_cache__memcpy(struct dso_cache *cache, u64 offset,
}

static ssize_t
-dso_cache__read(struct dso *dso, struct machine *machine,
- u64 offset, u8 *data, ssize_t size)
+dso_cache__read(struct dso *dso, u64 offset, u8 *data, ssize_t size)
{
- bool new_fd = dso->data.fd == -1;
struct dso_cache *cache;
ssize_t ret;
- int fd;
-
- fd = dso__data_fd(dso, machine);
- if (fd < 0)
- return -1;

do {
u64 cache_offset;
@@ -390,10 +384,10 @@ dso_cache__read(struct dso *dso, struct machine *machine,
cache_offset = offset & DSO__DATA_CACHE_MASK;
ret = -EINVAL;

- if (-1 == lseek(fd, cache_offset, SEEK_SET))
+ if (-1 == lseek(dso->data.fd, cache_offset, SEEK_SET))
break;

- ret = read(fd, cache->data, DSO__DATA_CACHE_SIZE);
+ ret = read(dso->data.fd, cache->data, DSO__DATA_CACHE_SIZE);
if (ret <= 0)
break;

@@ -408,15 +402,11 @@ dso_cache__read(struct dso *dso, struct machine *machine,
if (ret <= 0)
free(cache);

- /* Check the cache only if we just added new fd. */
- if (new_fd)
- data_close();
-
return ret;
}

-static ssize_t dso_cache_read(struct dso *dso, struct machine *machine,
- u64 offset, u8 *data, ssize_t size)
+static ssize_t dso_cache_read(struct dso *dso, u64 offset,
+ u8 *data, ssize_t size)
{
struct dso_cache *cache;

@@ -424,11 +414,10 @@ static ssize_t dso_cache_read(struct dso *dso, struct machine *machine,
if (cache)
return dso_cache__memcpy(cache, offset, data, size);
else
- return dso_cache__read(dso, machine, offset, data, size);
+ return dso_cache__read(dso, offset, data, size);
}

-ssize_t dso__data_read_offset(struct dso *dso, struct machine *machine,
- u64 offset, u8 *data, ssize_t size)
+static ssize_t cached_read(struct dso *dso, u64 offset, u8 *data, ssize_t size)
{
ssize_t r = 0;
u8 *p = data;
@@ -436,7 +425,7 @@ ssize_t dso__data_read_offset(struct dso *dso, struct machine *machine,
do {
ssize_t ret;

- ret = dso_cache_read(dso, machine, offset, p, size);
+ ret = dso_cache_read(dso, offset, p, size);
if (ret < 0)
return ret;

@@ -456,6 +445,55 @@ ssize_t dso__data_read_offset(struct dso *dso, struct machine *machine,
return r;
}

+static int data_file_size(struct dso *dso)
+{
+ struct stat st;
+
+ if (!dso->data.file_size) {
+ if (fstat(dso->data.fd, &st)) {
+ pr_err("dso mmap failed, fstat: %s\n", strerror(errno));
+ return -1;
+ }
+ dso->data.file_size = st.st_size;
+ }
+
+ return 0;
+}
+
+static ssize_t data_read_offset(struct dso *dso, u64 offset,
+ u8 *data, ssize_t size)
+{
+ if (data_file_size(dso))
+ return -1;
+
+ /* Check the offset sanity. */
+ if (offset > dso->data.file_size)
+ return -1;
+
+ if (offset + size < offset)
+ return -1;
+
+ return cached_read(dso, offset, data, size);
+}
+
+ssize_t dso__data_read_offset(struct dso *dso, struct machine *machine,
+ u64 offset, u8 *data, ssize_t size)
+{
+ bool new_fd = dso->data.fd == -1;
+ ssize_t ret;
+
+ if (dso__data_fd(dso, machine) < 0)
+ return -1;
+
+ ret = data_read_offset(dso, offset, data, size);
+
+ /* Check the cache only if we just added new fd. */
+ if (new_fd)
+ data_close();
+
+ return ret;
+}
+
ssize_t dso__data_read_addr(struct dso *dso, struct map *map,
struct machine *machine, u64 addr,
u8 *data, ssize_t size)
diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
index 90988bf..da47b13 100644
--- a/tools/perf/util/dso.h
+++ b/tools/perf/util/dso.h
@@ -103,6 +103,7 @@ struct dso {
struct {
struct rb_root cache;
int fd;
+ size_t file_size;
struct list_head open_entry;
} data;

--
1.8.3.1


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