liblog: use packed structs instead of raw unaligned reads
Per jmgao@, we still need to worry about unaligned integer accesses.
In any case, we already have the packed structs for all of the
unaligned data that we're reading, so this change favors using those
packed structs.
Bug: 142256213
Test: x86,arm32,arm64 liblog-unit-tests
Change-Id: I21fc629eac49895d03b5b31daa4cc494b0c4c230
diff --git a/liblog/include/private/android_logger.h b/liblog/include/private/android_logger.h
index 5e04148..d3cb571 100644
--- a/liblog/include/private/android_logger.h
+++ b/liblog/include/private/android_logger.h
@@ -57,6 +57,18 @@
int32_t tag; // Little Endian Order
} android_event_header_t;
+// Event payload EVENT_TYPE_LIST
+typedef struct __attribute__((__packed__)) {
+ int8_t type; // EVENT_TYPE_LIST
+ int8_t element_count;
+} android_event_list_t;
+
+// Event payload EVENT_TYPE_FLOAT
+typedef struct __attribute__((__packed__)) {
+ int8_t type; // EVENT_TYPE_FLOAT
+ float data;
+} android_event_float_t;
+
/* Event payload EVENT_TYPE_INT */
typedef struct __attribute__((__packed__)) {
int8_t type; // EVENT_TYPE_INT
diff --git a/liblog/log_event_list.cpp b/liblog/log_event_list.cpp
index 18ea930..7882c96 100644
--- a/liblog/log_event_list.cpp
+++ b/liblog/log_event_list.cpp
@@ -51,11 +51,9 @@
typedef struct android_log_context_internal android_log_context_internal;
static void init_context(android_log_context_internal* context, uint32_t tag) {
- size_t needed;
-
context->tag = tag;
context->read_write_flag = kAndroidLoggerWrite;
- needed = sizeof(uint8_t) + sizeof(uint8_t);
+ size_t needed = sizeof(android_event_list_t);
if ((context->pos + needed) > MAX_EVENT_PAYLOAD) {
context->overflow = true;
}
@@ -143,7 +141,6 @@
}
int android_log_write_list_begin(android_log_context ctx) {
- size_t needed;
android_log_context_internal* context;
context = (android_log_context_internal*)ctx;
@@ -154,7 +151,7 @@
context->overflow = true;
return -EOVERFLOW;
}
- needed = sizeof(uint8_t) + sizeof(uint8_t);
+ size_t needed = sizeof(android_event_list_t);
if ((context->pos + needed) > MAX_EVENT_PAYLOAD) {
context->overflow = true;
return -EIO;
@@ -168,8 +165,9 @@
if (context->overflow) {
return -EIO;
}
- context->storage[context->pos + 0] = EVENT_TYPE_LIST;
- context->storage[context->pos + 1] = 0;
+ auto* event_list = reinterpret_cast<android_event_list_t*>(&context->storage[context->pos]);
+ event_list->type = EVENT_TYPE_LIST;
+ event_list->element_count = 0;
context->list[context->list_nest_depth] = context->pos + 1;
context->count[context->list_nest_depth] = 0;
context->pos += needed;
@@ -177,57 +175,49 @@
}
int android_log_write_int32(android_log_context ctx, int32_t value) {
- size_t needed;
- android_log_context_internal* context;
-
- context = (android_log_context_internal*)ctx;
+ android_log_context_internal* context = (android_log_context_internal*)ctx;
if (!context || (kAndroidLoggerWrite != context->read_write_flag)) {
return -EBADF;
}
if (context->overflow) {
return -EIO;
}
- needed = sizeof(uint8_t) + sizeof(value);
+ size_t needed = sizeof(android_event_int_t);
if ((context->pos + needed) > MAX_EVENT_PAYLOAD) {
context->overflow = true;
return -EIO;
}
context->count[context->list_nest_depth]++;
- context->storage[context->pos + 0] = EVENT_TYPE_INT;
- *reinterpret_cast<int32_t*>(&context->storage[context->pos + 1]) = value;
+ auto* event_int = reinterpret_cast<android_event_int_t*>(&context->storage[context->pos]);
+ event_int->type = EVENT_TYPE_INT;
+ event_int->data = value;
context->pos += needed;
return 0;
}
int android_log_write_int64(android_log_context ctx, int64_t value) {
- size_t needed;
- android_log_context_internal* context;
-
- context = (android_log_context_internal*)ctx;
+ android_log_context_internal* context = (android_log_context_internal*)ctx;
if (!context || (kAndroidLoggerWrite != context->read_write_flag)) {
return -EBADF;
}
if (context->overflow) {
return -EIO;
}
- needed = sizeof(uint8_t) + sizeof(value);
+ size_t needed = sizeof(android_event_long_t);
if ((context->pos + needed) > MAX_EVENT_PAYLOAD) {
context->overflow = true;
return -EIO;
}
context->count[context->list_nest_depth]++;
- context->storage[context->pos + 0] = EVENT_TYPE_LONG;
- *reinterpret_cast<int64_t*>(&context->storage[context->pos + 1]) = value;
+ auto* event_long = reinterpret_cast<android_event_long_t*>(&context->storage[context->pos]);
+ event_long->type = EVENT_TYPE_LONG;
+ event_long->data = value;
context->pos += needed;
return 0;
}
int android_log_write_string8_len(android_log_context ctx, const char* value, size_t maxlen) {
- size_t needed;
- ssize_t len;
- android_log_context_internal* context;
-
- context = (android_log_context_internal*)ctx;
+ android_log_context_internal* context = (android_log_context_internal*)ctx;
if (!context || (kAndroidLoggerWrite != context->read_write_flag)) {
return -EBADF;
}
@@ -237,8 +227,8 @@
if (!value) {
value = "";
}
- len = strnlen(value, maxlen);
- needed = sizeof(uint8_t) + sizeof(int32_t) + len;
+ int32_t len = strnlen(value, maxlen);
+ size_t needed = sizeof(android_event_string_t) + len;
if ((context->pos + needed) > MAX_EVENT_PAYLOAD) {
/* Truncate string for delivery */
len = MAX_EVENT_PAYLOAD - context->pos - 1 - sizeof(int32_t);
@@ -248,10 +238,11 @@
}
}
context->count[context->list_nest_depth]++;
- context->storage[context->pos + 0] = EVENT_TYPE_STRING;
- *reinterpret_cast<ssize_t*>(&context->storage[context->pos + 1]) = len;
+ auto* event_string = reinterpret_cast<android_event_string_t*>(&context->storage[context->pos]);
+ event_string->type = EVENT_TYPE_STRING;
+ event_string->length = len;
if (len) {
- memcpy(&context->storage[context->pos + 5], value, len);
+ memcpy(&event_string->data, value, len);
}
context->pos += needed;
return len;
@@ -262,26 +253,22 @@
}
int android_log_write_float32(android_log_context ctx, float value) {
- size_t needed;
- uint32_t ivalue;
- android_log_context_internal* context;
-
- context = (android_log_context_internal*)ctx;
+ android_log_context_internal* context = (android_log_context_internal*)ctx;
if (!context || (kAndroidLoggerWrite != context->read_write_flag)) {
return -EBADF;
}
if (context->overflow) {
return -EIO;
}
- needed = sizeof(uint8_t) + sizeof(ivalue);
+ size_t needed = sizeof(android_event_float_t);
if ((context->pos + needed) > MAX_EVENT_PAYLOAD) {
context->overflow = true;
return -EIO;
}
- ivalue = *(uint32_t*)&value;
context->count[context->list_nest_depth]++;
- context->storage[context->pos + 0] = EVENT_TYPE_FLOAT;
- *reinterpret_cast<uint32_t*>(&context->storage[context->pos + 1]) = ivalue;
+ auto* event_float = reinterpret_cast<android_event_float_t*>(&context->storage[context->pos]);
+ event_float->type = EVENT_TYPE_FLOAT;
+ event_float->data = value;
context->pos += needed;
return 0;
}
@@ -443,20 +430,22 @@
return elem;
}
- elem.type = static_cast<AndroidEventLogType>(context->storage[pos++]);
+ elem.type = static_cast<AndroidEventLogType>(context->storage[pos]);
switch ((int)elem.type) {
case EVENT_TYPE_FLOAT:
/* Rely on union to translate elem.data.int32 into elem.data.float32 */
/* FALLTHRU */
- case EVENT_TYPE_INT:
+ case EVENT_TYPE_INT: {
elem.len = sizeof(int32_t);
- if ((pos + elem.len) > context->len) {
+ if ((pos + sizeof(android_event_int_t)) > context->len) {
elem.type = EVENT_TYPE_UNKNOWN;
return elem;
}
- elem.data.int32 = *reinterpret_cast<int32_t*>(&context->storage[pos]);
+
+ auto* event_int = reinterpret_cast<android_event_int_t*>(&context->storage[pos]);
+ pos += sizeof(android_event_int_t);
+ elem.data.int32 = event_int->data;
/* common tangeable object suffix */
- pos += elem.len;
elem.complete = !context->list_nest_depth && !context->count[0];
if (!peek) {
if (!context->count[context->list_nest_depth] ||
@@ -466,16 +455,19 @@
context->pos = pos;
}
return elem;
+ }
- case EVENT_TYPE_LONG:
+ case EVENT_TYPE_LONG: {
elem.len = sizeof(int64_t);
- if ((pos + elem.len) > context->len) {
+ if ((pos + sizeof(android_event_long_t)) > context->len) {
elem.type = EVENT_TYPE_UNKNOWN;
return elem;
}
- elem.data.int64 = *reinterpret_cast<int64_t*>(&context->storage[pos]);
+
+ auto* event_long = reinterpret_cast<android_event_long_t*>(&context->storage[pos]);
+ pos += sizeof(android_event_long_t);
+ elem.data.int64 = event_long->data;
/* common tangeable object suffix */
- pos += elem.len;
elem.complete = !context->list_nest_depth && !context->count[0];
if (!peek) {
if (!context->count[context->list_nest_depth] ||
@@ -485,15 +477,22 @@
context->pos = pos;
}
return elem;
+ }
- case EVENT_TYPE_STRING:
- if ((pos + sizeof(int32_t)) > context->len) {
+ case EVENT_TYPE_STRING: {
+ if ((pos + sizeof(android_event_string_t)) > context->len) {
elem.type = EVENT_TYPE_UNKNOWN;
elem.complete = true;
return elem;
}
- elem.len = *reinterpret_cast<int32_t*>(&context->storage[pos]);
- pos += sizeof(int32_t);
+ auto* event_string = reinterpret_cast<android_event_string_t*>(&context->storage[pos]);
+ pos += sizeof(android_event_string_t);
+ // Wire format is int32_t, but elem.len is uint16_t...
+ if (event_string->length >= UINT16_MAX) {
+ elem.type = EVENT_TYPE_UNKNOWN;
+ return elem;
+ }
+ elem.len = event_string->length;
if ((pos + elem.len) > context->len) {
elem.len = context->len - pos; /* truncate string */
elem.complete = true;
@@ -502,7 +501,7 @@
return elem;
}
}
- elem.data.string = (char*)&context->storage[pos];
+ elem.data.string = event_string->data;
/* common tangeable object suffix */
pos += elem.len;
elem.complete = !context->list_nest_depth && !context->count[0];
@@ -514,13 +513,16 @@
context->pos = pos;
}
return elem;
+ }
- case EVENT_TYPE_LIST:
- if ((pos + sizeof(uint8_t)) > context->len) {
+ case EVENT_TYPE_LIST: {
+ if ((pos + sizeof(android_event_list_t)) > context->len) {
elem.type = EVENT_TYPE_UNKNOWN;
elem.complete = true;
return elem;
}
+ auto* event_list = reinterpret_cast<android_event_list_t*>(&context->storage[pos]);
+ pos += sizeof(android_event_list_t);
elem.complete = context->list_nest_depth >= ANDROID_MAX_LIST_NEST_DEPTH;
if (peek) {
return elem;
@@ -528,15 +530,17 @@
if (context->count[context->list_nest_depth]) {
context->count[context->list_nest_depth]--;
}
- context->list_stop = !context->storage[pos];
+ context->list_stop = event_list->element_count == 0;
context->list_nest_depth++;
if (context->list_nest_depth <= ANDROID_MAX_LIST_NEST_DEPTH) {
- context->count[context->list_nest_depth] = context->storage[pos];
+ context->count[context->list_nest_depth] = event_list->element_count;
}
- context->pos = pos + sizeof(uint8_t);
+ context->pos = pos;
return elem;
+ }
case EVENT_TYPE_LIST_STOP: /* Suprise Newline terminates lists. */
+ pos++;
if (!peek) {
context->pos = pos;
}
diff --git a/liblog/logprint.cpp b/liblog/logprint.cpp
index dd2c797..82fbafd 100644
--- a/liblog/logprint.cpp
+++ b/liblog/logprint.cpp
@@ -35,8 +35,10 @@
#include <wchar.h>
#include <cutils/list.h>
+
#include <log/log.h>
#include <log/logprint.h>
+#include <private/android_logger.h>
#include "log_portability.h"
@@ -635,8 +637,7 @@
if (eventDataLen < 1) return -1;
- type = *eventData++;
- eventDataLen--;
+ type = *eventData;
cp = NULL;
len = 0;
@@ -725,22 +726,24 @@
case EVENT_TYPE_INT:
/* 32-bit signed int */
{
- int32_t ival;
-
- if (eventDataLen < 4) return -1;
- ival = *reinterpret_cast<const int32_t*>(eventData);
- eventData += 4;
- eventDataLen -= 4;
-
- lval = ival;
+ if (eventDataLen < sizeof(android_event_int_t)) return -1;
+ auto* event_int = reinterpret_cast<const android_event_int_t*>(eventData);
+ lval = event_int->data;
+ eventData += sizeof(android_event_int_t);
+ eventDataLen -= sizeof(android_event_int_t);
}
goto pr_lval;
case EVENT_TYPE_LONG:
/* 64-bit signed long */
- if (eventDataLen < 8) return -1;
- lval = *reinterpret_cast<const int64_t*>(eventData);
- eventData += 8;
- eventDataLen -= 8;
+ if (eventDataLen < sizeof(android_event_long_t)) {
+ return -1;
+ }
+ {
+ auto* event_long = reinterpret_cast<const android_event_long_t*>(eventData);
+ lval = event_long->data;
+ }
+ eventData += sizeof(android_event_long_t);
+ eventDataLen -= sizeof(android_event_long_t);
pr_lval:
outCount = snprintf(outBuf, outBufLen, "%" PRId64, lval);
if (outCount < outBufLen) {
@@ -754,14 +757,11 @@
case EVENT_TYPE_FLOAT:
/* float */
{
- uint32_t ival;
- float fval;
-
- if (eventDataLen < 4) return -1;
- ival = *reinterpret_cast<const uint32_t*>(eventData);
- fval = *(float*)&ival;
- eventData += 4;
- eventDataLen -= 4;
+ if (eventDataLen < sizeof(android_event_float_t)) return -1;
+ auto* event_float = reinterpret_cast<const android_event_float_t*>(eventData);
+ float fval = event_float->data;
+ eventData += sizeof(android_event_int_t);
+ eventDataLen -= sizeof(android_event_int_t);
outCount = snprintf(outBuf, outBufLen, "%f", fval);
if (outCount < outBufLen) {
@@ -776,12 +776,11 @@
case EVENT_TYPE_STRING:
/* UTF-8 chars, not NULL-terminated */
{
- unsigned int strLen;
-
- if (eventDataLen < 4) return -1;
- strLen = *reinterpret_cast<const uint32_t*>(eventData);
- eventData += 4;
- eventDataLen -= 4;
+ if (eventDataLen < sizeof(android_event_string_t)) return -1;
+ auto* event_string = reinterpret_cast<const android_event_string_t*>(eventData);
+ unsigned int strLen = event_string->length;
+ eventData += sizeof(android_event_string_t);
+ eventDataLen -= sizeof(android_event_string_t);
if (eventDataLen < strLen) {
result = -1; /* mark truncated */
@@ -814,20 +813,19 @@
case EVENT_TYPE_LIST:
/* N items, all different types */
{
- unsigned char count;
- int i;
+ if (eventDataLen < sizeof(android_event_list_t)) return -1;
+ auto* event_list = reinterpret_cast<const android_event_list_t*>(eventData);
- if (eventDataLen < 1) return -1;
-
- count = *eventData++;
- eventDataLen--;
+ int8_t count = event_list->element_count;
+ eventData += sizeof(android_event_list_t);
+ eventDataLen -= sizeof(android_event_list_t);
if (outBufLen <= 0) goto no_room;
*outBuf++ = '[';
outBufLen--;
- for (i = 0; i < count; i++) {
+ for (int i = 0; i < count; i++) {
result = android_log_printBinaryEvent(&eventData, &eventDataLen, &outBuf, &outBufLen,
fmtStr, fmtLen);
if (result != 0) goto bail;
@@ -1017,10 +1015,11 @@
}
}
inCount = buf->len;
- if (inCount < 4) return -1;
- tagIndex = *reinterpret_cast<const uint32_t*>(eventData);
- eventData += 4;
- inCount -= 4;
+ if (inCount < sizeof(android_event_header_t)) return -1;
+ auto* event_header = reinterpret_cast<const android_event_header_t*>(eventData);
+ tagIndex = event_header->tag;
+ eventData += sizeof(android_event_header_t);
+ inCount -= sizeof(android_event_header_t);
entry->tagLen = 0;
entry->tag = NULL;
diff --git a/liblog/tests/liblog_test.cpp b/liblog/tests/liblog_test.cpp
index 9780b28..cfcfd99 100644
--- a/liblog/tests/liblog_test.cpp
+++ b/liblog/tests/liblog_test.cpp
@@ -1924,10 +1924,10 @@
char* original = eventData;
// Tag
- int tag = *reinterpret_cast<int32_t*>(eventData);
- eventData += 4;
+ auto* event_header = reinterpret_cast<android_event_header_t*>(eventData);
+ eventData += sizeof(android_event_header_t);
- if (tag != TAG) {
+ if (event_header->tag != TAG) {
continue;
}
@@ -1938,45 +1938,37 @@
}
// List type
- ASSERT_EQ(EVENT_TYPE_LIST, eventData[0]);
- eventData++;
-
- // Number of elements in list
- ASSERT_EQ(3, eventData[0]);
- eventData++;
+ auto* event_list = reinterpret_cast<android_event_list_t*>(eventData);
+ ASSERT_EQ(EVENT_TYPE_LIST, event_list->type);
+ ASSERT_EQ(3, event_list->element_count);
+ eventData += sizeof(android_event_list_t);
// Element #1: string type for subtag
- ASSERT_EQ(EVENT_TYPE_STRING, eventData[0]);
- eventData++;
-
+ auto* event_string_subtag = reinterpret_cast<android_event_string_t*>(eventData);
+ ASSERT_EQ(EVENT_TYPE_STRING, event_string_subtag->type);
unsigned subtag_len = strlen(SUBTAG);
if (subtag_len > 32) subtag_len = 32;
- ASSERT_EQ(subtag_len, *reinterpret_cast<uint32_t*>(eventData));
- eventData += 4;
-
- if (memcmp(SUBTAG, eventData, subtag_len)) {
+ ASSERT_EQ(static_cast<int32_t>(subtag_len), event_string_subtag->length);
+ if (memcmp(SUBTAG, &event_string_subtag->data, subtag_len)) {
continue;
}
- eventData += subtag_len;
+ eventData += sizeof(android_event_string_t) + subtag_len;
// Element #2: int type for uid
- ASSERT_EQ(EVENT_TYPE_INT, eventData[0]);
- eventData++;
-
- ASSERT_EQ(UID, *reinterpret_cast<int32_t*>(eventData));
- eventData += 4;
+ auto* event_int_uid = reinterpret_cast<android_event_int_t*>(eventData);
+ ASSERT_EQ(EVENT_TYPE_INT, event_int_uid->type);
+ ASSERT_EQ(UID, event_int_uid->data);
+ eventData += sizeof(android_event_int_t);
// Element #3: string type for data
- ASSERT_EQ(EVENT_TYPE_STRING, eventData[0]);
- eventData++;
-
- size_t dataLen = *reinterpret_cast<int32_t*>(eventData);
- eventData += 4;
+ auto* event_string_data = reinterpret_cast<android_event_string_t*>(eventData);
+ ASSERT_EQ(EVENT_TYPE_STRING, event_string_data->type);
+ size_t dataLen = event_string_data->length;
if (DATA_LEN < 512) ASSERT_EQ(DATA_LEN, (int)dataLen);
-
- if (memcmp(payload, eventData, dataLen)) {
+ if (memcmp(payload, &event_string_data->data, dataLen)) {
continue;
}
+ eventData += sizeof(android_event_string_t);
if (DATA_LEN >= 512) {
eventData += dataLen;
@@ -2082,10 +2074,12 @@
if (!eventData) continue;
// Tag
- int tag = *reinterpret_cast<int32_t*>(eventData);
- eventData += 4;
+ auto* event_header = reinterpret_cast<android_event_header_t*>(eventData);
+ eventData += sizeof(android_event_header_t);
- if (tag != TAG) continue;
+ if (event_header->tag != TAG) {
+ continue;
+ }
if (!SUBTAG) {
// This tag should not have been written because the data was null
@@ -2135,10 +2129,10 @@
}
// Tag
- int tag = *reinterpret_cast<int32_t*>(eventData);
- eventData += 4;
+ auto* event_header = reinterpret_cast<android_event_header_t*>(eventData);
+ eventData += sizeof(android_event_header_t);
- if (tag != TAG) {
+ if (event_header->tag != TAG) {
continue;
}
@@ -2149,21 +2143,17 @@
}
// List type
- ASSERT_EQ(EVENT_TYPE_LIST, eventData[0]);
- eventData++;
-
- // Number of elements in list
- ASSERT_EQ(3, eventData[0]);
- eventData++;
+ auto* event_list = reinterpret_cast<android_event_list_t*>(eventData);
+ ASSERT_EQ(EVENT_TYPE_LIST, event_list->type);
+ ASSERT_EQ(3, event_list->element_count);
+ eventData += sizeof(android_event_list_t);
// Element #1: string type for subtag
- ASSERT_EQ(EVENT_TYPE_STRING, eventData[0]);
- eventData++;
+ auto* event_string = reinterpret_cast<android_event_string_t*>(eventData);
+ ASSERT_EQ(EVENT_TYPE_STRING, event_string->type);
+ ASSERT_EQ(static_cast<int32_t>(strlen(SUBTAG)), event_string->length);
- ASSERT_EQ(strlen(SUBTAG), *reinterpret_cast<uint32_t*>(eventData));
- eventData += 4;
-
- if (memcmp(SUBTAG, eventData, strlen(SUBTAG))) {
+ if (memcmp(SUBTAG, &event_string->data, strlen(SUBTAG))) {
continue;
}
++count;
@@ -2673,13 +2663,14 @@
// test buffer reading API
int buffer_to_string = -1;
if (eventData) {
- snprintf(msgBuf, sizeof(msgBuf), "I/[%" PRIu32 "]", *reinterpret_cast<uint32_t*>(eventData));
+ auto* event_header = reinterpret_cast<android_event_header_t*>(eventData);
+ eventData += sizeof(android_event_header_t);
+ snprintf(msgBuf, sizeof(msgBuf), "I/[%" PRId32 "]", event_header->tag);
print_barrier();
fprintf(stderr, "%-10s(%5u): ", msgBuf, pid);
memset(msgBuf, 0, sizeof(msgBuf));
- buffer_to_string = android_log_buffer_to_string(
- eventData + sizeof(uint32_t), log_msg.entry.len - sizeof(uint32_t),
- msgBuf, sizeof(msgBuf));
+ buffer_to_string =
+ android_log_buffer_to_string(eventData, log_msg.entry.len, msgBuf, sizeof(msgBuf));
fprintf(stderr, "%s\n", msgBuf);
print_barrier();
}