logd: klogd and Mediatek
(cherry pick from commit 46d159d4626ca5d5667b739792840c3178a1457b)
- sniff for PID in kernel log messages if available
- properly deal with klogd watermark in face of modified output
- deal more stringently with priority tag, must have [ following
- suppress process-name stutter in tag that can happen
- do not use : to demark tag if within [ ]
Mediatek-special change that adds <printk_state>(<cpu>)[<pid>:<comm>]
as a prefix to the printk messages. Along the lines of (simplified
for entertainment purposes, YMMV):
char tbuf[50]; /* printk prefix */
int this_cpu = smp_processor_id();
char state = __raw_get_cpu_var(printk_state);
unsigned tlen = snprintf(tbuf, sizeof(tbuf), "%c(%x)[%d:%s]",
state, this_cpu, current->pid, current->comm);
Bug: 23517551
Change-Id: I568e25c5aa6d8474835454a0e83b19c2921b7985
diff --git a/logd/LogKlog.cpp b/logd/LogKlog.cpp
index 39da87c..0a5df24 100644
--- a/logd/LogKlog.cpp
+++ b/logd/LogKlog.cpp
@@ -48,7 +48,7 @@
char c;
while (((c = *s++)) && (++len <= max_prio_len)) {
if (!isdigit(c)) {
- return (c == '>') ? s : NULL;
+ return ((c == '>') && (*s == '[')) ? s : NULL;
}
}
return NULL;
@@ -296,6 +296,22 @@
}
}
+pid_t LogKlog::sniffPid(const char *cp) {
+ while (*cp) {
+ // Mediatek kernels with modified printk
+ if (*cp == '[') {
+ int pid = 0;
+ char dummy;
+ if (sscanf(cp, "[%d:%*[a-z_./0-9:A-Z]]%c", &pid, &dummy) == 2) {
+ return pid;
+ }
+ break; // Only the first one
+ }
+ ++cp;
+ }
+ return 0;
+}
+
// Passed the entire SYSLOG_ACTION_READ_ALL buffer and interpret a
// compensated start time.
void LogKlog::synchronize(const char *buf) {
@@ -419,9 +435,9 @@
// sniff for start marker
const char klogd_message[] = "logd.klogd: ";
- if (!strncmp(buf, klogd_message, sizeof(klogd_message) - 1)) {
- char *endp;
- uint64_t sig = strtoll(buf + sizeof(klogd_message) - 1, &endp, 10);
+ const char *start = strstr(buf, klogd_message);
+ if (start) {
+ uint64_t sig = strtoll(start + sizeof(klogd_message) - 1, NULL, 10);
if (sig == signature.nsec()) {
if (initialized) {
enableLogging = true;
@@ -437,10 +453,10 @@
return 0;
}
- // Parse pid, tid and uid (not possible)
- const pid_t pid = 0;
- const pid_t tid = 0;
- const uid_t uid = 0;
+ // Parse pid, tid and uid
+ const pid_t pid = sniffPid(buf);
+ const pid_t tid = pid;
+ const uid_t uid = pid ? logbuf->pidToUid(pid) : 0;
// Parse (rules at top) to pull out a tag from the incoming kernel message.
// Some may view the following as an ugly heuristic, the desire is to
@@ -452,7 +468,7 @@
if (!*buf) {
return 0;
}
- const char *start = buf;
+ start = buf;
const char *tag = "";
const char *etag = tag;
if (!isspace(*buf)) {
@@ -463,7 +479,14 @@
// <PRI>[<TIME>] "[INFO]"<tag> ":" message
bt = buf + 6;
}
- for(et = bt; *et && (*et != ':') && !isspace(*et); ++et);
+ for(et = bt; *et && (*et != ':') && !isspace(*et); ++et) {
+ // skip ':' within [ ... ]
+ if (*et == '[') {
+ while (*et && *et != ']') {
+ ++et;
+ }
+ }
+ }
for(cp = et; isspace(*cp); ++cp);
size_t size;
@@ -560,7 +583,17 @@
etag = tag = "";
}
}
- size_t l = etag - tag;
+ // Suppress additional stutter in tag:
+ // eg: [143:healthd]healthd -> [143:healthd]
+ size_t taglen = etag - tag;
+ // Mediatek-special printk induced stutter
+ char *np = strrchr(tag, ']');
+ if (np && (++np < etag)) {
+ size_t s = etag - np;
+ if (((s + s) < taglen) && !strncmp(np, np - 1 - s, s)) {
+ taglen = np - tag;
+ }
+ }
// skip leading space
while (isspace(*buf)) {
++buf;
@@ -571,11 +604,11 @@
--b;
}
// trick ... allow tag with empty content to be logged. log() drops empty
- if (!b && l) {
+ if (!b && taglen) {
buf = " ";
b = 1;
}
- size_t n = 1 + l + 1 + b + 1;
+ size_t n = 1 + taglen + 1 + b + 1;
// Allocate a buffer to hold the interpreted log message
int rc = n;
@@ -584,15 +617,15 @@
rc = -ENOMEM;
return rc;
}
- char *np = newstr;
+ np = newstr;
// Convert priority into single-byte Android logger priority
*np = convertKernelPrioToAndroidPrio(pri);
++np;
// Copy parsed tag following priority
- strncpy(np, tag, l);
- np += l;
+ strncpy(np, tag, taglen);
+ np += taglen;
*np = '\0';
++np;
diff --git a/logd/LogKlog.h b/logd/LogKlog.h
index a898c63..081d344 100644
--- a/logd/LogKlog.h
+++ b/logd/LogKlog.h
@@ -49,6 +49,7 @@
protected:
void sniffTime(log_time &now, const char **buf, bool reverse);
+ pid_t sniffPid(const char *buf);
void calculateCorrection(const log_time &monotonic, const char *real_string);
virtual bool onDataAvailable(SocketClient *cli);
