liblog: add /dev/event-log-tags for Tag Map
android_openEventTagMap(NULL) will open and mix content from
/system/etc/event-log-tags and /dev/event-log-tags. Only
reports identicals if global.
Test: gTest logd-unit-tests and liblog-unit-tests, liblog-benchmarks.
Bug: 31456426
Change-Id: Ic17d52a7829a4daaf013828d08fc1c09446ae8ef
diff --git a/liblog/event_tag_map.cpp b/liblog/event_tag_map.cpp
index c53ea2c..fec5dee 100644
--- a/liblog/event_tag_map.cpp
+++ b/liblog/event_tag_map.cpp
@@ -53,21 +53,27 @@
// Map
struct EventTagMap {
+# define NUM_MAPS 2
// memory-mapped source file; we get strings from here
- void* mapAddr;
- size_t mapLen;
+ void* mapAddr[NUM_MAPS];
+ size_t mapLen[NUM_MAPS];
private:
std::unordered_map<uint32_t, TagFmt> Idx2TagFmt;
public:
- EventTagMap() : mapAddr(NULL), mapLen(0) { }
+ EventTagMap() {
+ memset(mapAddr, 0, sizeof(mapAddr));
+ memset(mapLen, 0, sizeof(mapLen));
+ }
~EventTagMap() {
Idx2TagFmt.clear();
- if (mapAddr) {
- munmap(mapAddr, mapLen);
- mapAddr = 0;
+ for (size_t which = 0; which < NUM_MAPS; ++which) {
+ if (mapAddr[which]) {
+ munmap(mapAddr[which], mapLen[which]);
+ mapAddr[which] = 0;
+ }
}
}
@@ -157,6 +163,19 @@
fmtLen = cp - fmt;
}
+ // KISS Only report identicals if they are global
+ // Ideally we want to check if there are identicals
+ // recorded for the same uid, but recording that
+ // unused detail in our database is too burdensome.
+ bool verbose = true;
+ while ((*cp != '#') && (*cp != '\n')) ++cp;
+ if (*cp == '#') {
+ do {
+ ++cp;
+ } while (isspace(*cp) && (*cp != '\n'));
+ verbose = !!fastcmp<strncmp>(cp, "uid=", strlen("uid="));
+ }
+
while (*cp != '\n') ++cp;
#ifdef DEBUG
fprintf(stderr, "%d: %p: %.*s\n", lineNum, tag, (int)(cp - *pData), *pData);
@@ -164,24 +183,33 @@
*pData = cp;
if (map->emplaceUnique(tagIndex, TagFmt(std::make_pair(
- MapString(tag, tagLen), MapString(fmt, fmtLen))), true)) {
+ MapString(tag, tagLen), MapString(fmt, fmtLen))), verbose)) {
return 0;
}
errno = EMLINK;
return -1;
}
+static const char* eventTagFiles[NUM_MAPS] = {
+ EVENT_TAG_MAP_FILE,
+ "/dev/event-log-tags",
+};
+
// Parse the tags out of the file.
-static int parseMapLines(EventTagMap* map) {
- char* cp = static_cast<char*>(map->mapAddr);
- size_t len = map->mapLen;
+static int parseMapLines(EventTagMap* map, size_t which) {
+ char* cp = static_cast<char*>(map->mapAddr[which]);
+ size_t len = map->mapLen[which];
char* endp = cp + len;
// insist on EOL at EOF; simplifies parsing and null-termination
if (!len || (*(endp - 1) != '\n')) {
#ifdef DEBUG
- fprintf(stderr, OUT_TAG ": map file missing EOL on last line\n");
+ fprintf(stderr, OUT_TAG ": map file %zu[%zu] missing EOL on last line\n",
+ which, len);
#endif
+ if (which) { // do not propagate errors for other files
+ return 0;
+ }
errno = EINVAL;
return -1;
}
@@ -199,7 +227,9 @@
} else if (isdigit(*cp)) {
// looks like a tag; scan it out
if (scanTagLine(map, &cp, lineNum) != 0) {
- return -1;
+ if (!which || (errno != EMLINK)) {
+ return -1;
+ }
}
lineNum++; // we eat the '\n'
// leave lineStart==true
@@ -226,57 +256,87 @@
// We create a private mapping because we want to terminate the log tag
// strings with '\0'.
LIBLOG_ABI_PUBLIC EventTagMap* android_openEventTagMap(const char* fileName) {
- int save_errno;
+ EventTagMap* newTagMap;
+ off_t end[NUM_MAPS];
+ int save_errno, fd[NUM_MAPS];
+ size_t which;
- const char* tagfile = fileName ? fileName : EVENT_TAG_MAP_FILE;
- int fd = open(tagfile, O_RDONLY | O_CLOEXEC);
- if (fd < 0) {
+ memset(fd, -1, sizeof(fd));
+ memset(end, 0, sizeof(end));
+
+ for (which = 0; which < NUM_MAPS; ++which) {
+ const char* tagfile = fileName ? fileName : eventTagFiles[which];
+
+ fd[which] = open(tagfile, O_RDONLY | O_CLOEXEC);
+ if (fd[which] < 0) {
+ if (!which) {
+ save_errno = errno;
+ fprintf(stderr, OUT_TAG ": unable to open map '%s': %s\n",
+ tagfile, strerror(save_errno));
+ goto fail_errno;
+ }
+ continue;
+ }
+ end[which] = lseek(fd[which], 0L, SEEK_END);
save_errno = errno;
- fprintf(stderr, OUT_TAG ": unable to open map '%s': %s\n",
- tagfile, strerror(save_errno));
- errno = save_errno;
- return NULL;
- }
- off_t end = lseek(fd, 0L, SEEK_END);
- save_errno = errno;
- (void)lseek(fd, 0L, SEEK_SET);
- if (end < 0) {
- fprintf(stderr, OUT_TAG ": unable to seek map '%s' %s\n",
- tagfile, strerror(save_errno));
- close(fd);
- errno = save_errno;
- return NULL;
+ (void)lseek(fd[which], 0L, SEEK_SET);
+ if (!which && (end[0] < 0)) {
+ fprintf(stderr, OUT_TAG ": unable to seek map '%s' %s\n",
+ tagfile, strerror(save_errno));
+ goto fail_close;
+ }
+ if (fileName) break; // Only allow one as specified
}
- EventTagMap* newTagMap = new EventTagMap;
+ newTagMap = new EventTagMap;
if (newTagMap == NULL) {
save_errno = errno;
- close(fd);
- errno = save_errno;
- return NULL;
+ goto fail_close;
}
- newTagMap->mapAddr = mmap(NULL, end, PROT_READ | PROT_WRITE,
- MAP_PRIVATE, fd, 0);
- save_errno = errno;
- close(fd);
- fd = -1;
- if ((newTagMap->mapAddr == MAP_FAILED) || (newTagMap->mapAddr == NULL)) {
- fprintf(stderr, OUT_TAG ": mmap(%s) failed: %s\n",
- tagfile, strerror(save_errno));
- delete newTagMap;
- errno = save_errno;
- return NULL;
+ for (which = 0; which < NUM_MAPS; ++which) {
+ if (fd[which] >= 0) {
+ newTagMap->mapAddr[which] = mmap(NULL, end[which],
+ which ?
+ PROT_READ :
+ PROT_READ | PROT_WRITE,
+ which ?
+ MAP_SHARED :
+ MAP_PRIVATE,
+ fd[which], 0);
+ save_errno = errno;
+ close(fd[which]);
+ fd[which] = -1;
+ if ((newTagMap->mapAddr[which] != MAP_FAILED) &&
+ (newTagMap->mapAddr[which] != NULL)) {
+ newTagMap->mapLen[which] = end[which];
+ } else if (!which) {
+ const char* tagfile = fileName ? fileName : eventTagFiles[which];
+
+ fprintf(stderr, OUT_TAG ": mmap(%s) failed: %s\n",
+ tagfile, strerror(save_errno));
+ goto fail_unmap;
+ }
+ }
}
- newTagMap->mapLen = end;
-
- if (parseMapLines(newTagMap) != 0) {
- delete newTagMap;
- return NULL;
+ for (which = 0; which < NUM_MAPS; ++which) {
+ if (parseMapLines(newTagMap, which) != 0) {
+ delete newTagMap;
+ return NULL;
+ }
}
return newTagMap;
+
+fail_unmap:
+ save_errno = EINVAL;
+ delete newTagMap;
+fail_close:
+ for (which = 0; which < NUM_MAPS; ++which) close(fd[which]);
+fail_errno:
+ errno = save_errno;
+ return NULL;
}
// Close the map.