[PATCH 08/21] dm: Use static constants for offset sizes
Eugene Syromyatnikov
evgsyr at gmail.com
Sun Oct 9 13:30:06 UTC 2016
This may improve readability an leads to more compact code.
---
dm.c | 58 +++++++++++++++++++++++++++++++---------------------------
1 file changed, 31 insertions(+), 27 deletions(-)
diff --git a/dm.c b/dm.c
index 66b615d..adfa97e 100644
--- a/dm.c
+++ b/dm.c
@@ -102,12 +102,14 @@ static void
dm_decode_dm_target_spec(struct tcb *tcp, const struct dm_ioctl *ioc,
const char *extra, uint32_t extra_size)
{
+ static const uint32_t target_spec_size =
+ sizeof(struct dm_target_spec);
uint32_t i;
uint32_t offset = ioc->data_start;
for (i = 0; i < ioc->target_count; i++) {
- if (offset + (uint32_t) sizeof(struct dm_target_spec) >= offset &&
- offset + (uint32_t) sizeof(struct dm_target_spec) < extra_size) {
+ if (offset + target_spec_size >= offset &&
+ offset + target_spec_size < extra_size) {
uint32_t new_offset;
const struct dm_target_spec *s =
(const struct dm_target_spec *) (extra + offset);
@@ -121,16 +123,14 @@ dm_decode_dm_target_spec(struct tcb *tcp, const struct dm_ioctl *ioc,
QUOTE_0_TERMINATED);
tprints(", string=");
print_quoted_string((const char *) (s + 1), extra_size -
- (offset +
- sizeof(struct dm_target_spec)),
+ (offset + target_spec_size),
QUOTE_0_TERMINATED);
tprintf("}");
if (entering(tcp))
new_offset = offset + s->next;
else
new_offset = ioc->data_start + s->next;
- if (new_offset <= offset +
- (uint32_t) sizeof(struct dm_target_spec))
+ if (new_offset <= offset + target_spec_size)
goto misplaced;
offset = new_offset;
} else {
@@ -145,13 +145,15 @@ static void
dm_decode_dm_target_deps(const struct dm_ioctl *ioc, const char *extra,
uint32_t extra_size)
{
+ static const uint32_t target_deps_dev_offs =
+ offsetof(struct dm_target_deps, dev);
uint32_t offset = ioc->data_start;
- if (offset + (uint32_t) offsetof(struct dm_target_deps, dev) >= offset &&
- offset + (uint32_t) offsetof(struct dm_target_deps, dev) <= extra_size) {
+ if (offset + target_deps_dev_offs >= offset &&
+ offset + target_deps_dev_offs <= extra_size) {
uint32_t i;
- uint32_t space = (extra_size - (offset +
- offsetof(struct dm_target_deps, dev))) / sizeof(__u64);
+ uint32_t space = (extra_size - offset - target_deps_dev_offs) /
+ sizeof(__u64);
const struct dm_target_deps *s =
(const struct dm_target_deps *) (extra + offset);
@@ -173,11 +175,13 @@ static void
dm_decode_dm_name_list(const struct dm_ioctl *ioc, const char *extra,
uint32_t extra_size)
{
+ static const uint32_t name_list_name_offs =
+ offsetof(struct dm_name_list, name);
uint32_t offset = ioc->data_start;
while (1) {
- if (offset + (uint32_t) offsetof(struct dm_name_list, name) >= offset &&
- offset + (uint32_t) offsetof(struct dm_name_list, name) < extra_size) {
+ if (offset + name_list_name_offs >= offset &&
+ offset + name_list_name_offs < extra_size) {
const struct dm_name_list *s =
(const struct dm_name_list *) (extra + offset);
@@ -186,13 +190,12 @@ dm_decode_dm_name_list(const struct dm_ioctl *ioc, const char *extra,
tprintf(", {dev=makedev(%u, %u), name=", major(s->dev),
minor(s->dev));
print_quoted_string(s->name, extra_size - (offset +
- offsetof(struct dm_name_list,
- name)), QUOTE_0_TERMINATED);
+ name_list_name_offs),
+ QUOTE_0_TERMINATED);
tprints("}");
if (!s->next)
break;
- if (offset + s->next <= offset +
- (uint32_t) offsetof(struct dm_name_list, name))
+ if (offset + s->next <= offset + name_list_name_offs)
goto misplaced;
offset = offset + s->next;
} else {
@@ -207,26 +210,25 @@ static void
dm_decode_dm_target_versions(const struct dm_ioctl *ioc, const char *extra,
uint32_t extra_size)
{
+ static const uint32_t target_vers_name_offs =
+ offsetof(struct dm_target_versions, name);
uint32_t offset = ioc->data_start;
while (1) {
- if (offset + (uint32_t) offsetof(struct dm_target_versions, name) >=
- offset &&
- offset + (uint32_t) offsetof(struct dm_target_versions, name) <
- extra_size) {
+ if (offset + target_vers_name_offs >= offset &&
+ offset + target_vers_name_offs < extra_size) {
const struct dm_target_versions *s =
(const struct dm_target_versions *)(extra + offset);
tprints(", {name=");
print_quoted_string(s->name, extra_size - (offset +
- offsetof(struct dm_target_versions,
- name)), QUOTE_0_TERMINATED);
+ target_vers_name_offs),
+ QUOTE_0_TERMINATED);
tprintf(", version=%" PRIu32 ".%" PRIu32 ".%" PRIu32 "}",
s->version[0], s->version[1], s->version[2]);
if (!s->next)
break;
- if (offset + s->next <= offset +
- (uint32_t) offsetof(struct dm_target_versions, name))
+ if (offset + s->next <= offset + target_vers_name_offs)
goto misplaced;
offset = offset + s->next;
} else {
@@ -242,17 +244,19 @@ static void
dm_decode_dm_target_msg(const struct dm_ioctl *ioc, const char *extra,
uint32_t extra_size)
{
+ static const uint32_t target_msg_message_offs =
+ offsetof(struct dm_target_msg, message);
uint32_t offset = ioc->data_start;
- if (offset + (uint32_t) offsetof(struct dm_target_msg, message) >= offset &&
- offset + (uint32_t) offsetof(struct dm_target_msg, message) < extra_size) {
+ if (offset + target_msg_message_offs >= offset &&
+ offset + target_msg_message_offs < extra_size) {
const struct dm_target_msg *s =
(const struct dm_target_msg *) (extra + offset);
tprintf(", {sector=%" PRIu64 ", message=",
(uint64_t) s->sector);
print_quoted_string(s->message, extra_size -
- offsetof(struct dm_target_msg, message),
+ target_msg_message_offs,
QUOTE_0_TERMINATED);
tprints("}");
} else {
--
1.7.10.4
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