logd: missing klogd content
- regression in log_strtok_r (part deux) In commit
'logd: fix kernel logline stutter'
2c3b300fd8307e8da13608197d0a89bc613de5fb we introduced log_strtok_r.
as a replacement for strtok_r that dealt with a problem with
some kernel log messages. Fix is to refine definition of
is_timestamp to not match on patterns like [0], requiring
a single period. Another fix is to refine definition of
is_prio to properly escape non-digit content.
- Missing content because SYSLOG_ACTION_SIZE_BUFFER with added logging
is too short for full read of SYSLOG_ACTION_READ_ALL dropping
initial content. Add a margin for additional 1024 bytes.
- Absolute _first_ log entry has sequence number of 1, which is
specifically dropped, start sequence count at 1 rather than 0.
- Remove trailing space for efficiency.
- If tag exists but no content, trick into kernel logging.
Bug: 21851884
Change-Id: I0867a555a3bca09bbf18d18e75e41dffffe57a23
diff --git a/logd/LogBufferElement.cpp b/logd/LogBufferElement.cpp
index 7df1123..3f5fdce 100644
--- a/logd/LogBufferElement.cpp
+++ b/logd/LogBufferElement.cpp
@@ -30,7 +30,7 @@
#include "LogReader.h"
const uint64_t LogBufferElement::FLUSH_ERROR(0);
-atomic_int_fast64_t LogBufferElement::sequence;
+atomic_int_fast64_t LogBufferElement::sequence(1);
LogBufferElement::LogBufferElement(log_id_t log_id, log_time realtime,
uid_t uid, pid_t pid, pid_t tid,
diff --git a/logd/LogKlog.cpp b/logd/LogKlog.cpp
index 7d14648..d578c04 100644
--- a/logd/LogKlog.cpp
+++ b/logd/LogKlog.cpp
@@ -45,8 +45,8 @@
}
char c;
while ((c = *s++)) {
- if (!isdigit(c) && (c == '>')) {
- return s;
+ if (!isdigit(c)) {
+ return (c == '>') ? s : NULL;
}
}
return NULL;
@@ -65,17 +65,15 @@
while ((c = *s++)) {
if ((c == '.') && first_period) {
first_period = false;
- continue;
- }
- if (!isdigit(c) && (c == ']')) {
- return s;
+ } else if (!isdigit(c)) {
+ return ((c == ']') && !first_period && (*s == ' ')) ? s : NULL;
}
}
return NULL;
}
// Like strtok_r with "\r\n" except that we look for log signatures (regex)
-// \(\(<[0-9]+>\)\([[] *[0-9]+[]]\)\{0,1\}\|[[] *[0-9]+[]]\)
+// \(\(<[0-9]+>\)\([[] *[0-9]+[.][0-9]+[]] \)\{0,1\}\|[[] *[0-9]+[.][0-9]+[]] \)
// and split if we see a second one without a newline.
#define SIGNATURE_MASK 0xF0
@@ -547,10 +545,21 @@
}
}
size_t l = etag - tag;
+ // skip leading space
while (isspace(*buf)) {
++buf;
}
- size_t n = 1 + l + 1 + strlen(buf) + 1;
+ // truncate trailing space
+ size_t b = strlen(buf);
+ while (b && isspace(buf[b-1])) {
+ --b;
+ }
+ // trick ... allow tag with empty content to be logged. log() drops empty
+ if (!b && l) {
+ buf = " ";
+ b = 1;
+ }
+ size_t n = 1 + l + 1 + b + 1;
// Allocate a buffer to hold the interpreted log message
int rc = n;
@@ -572,7 +581,8 @@
++np;
// Copy main message to the remainder
- strcpy(np, buf);
+ strncpy(np, buf, b);
+ np[b] = '\0';
// Log message
rc = logbuf->log(LOG_ID_KERNEL, now, uid, pid, tid, newstr,
diff --git a/logd/main.cpp b/logd/main.cpp
index a876c99..9b88983 100644
--- a/logd/main.cpp
+++ b/logd/main.cpp
@@ -33,6 +33,8 @@
#include <syslog.h>
#include <unistd.h>
+#include <memory>
+
#include <cutils/properties.h>
#include <cutils/sched_policy.h>
#include <cutils/sockets.h>
@@ -275,6 +277,45 @@
&& !property_get_bool("ro.config.low_ram", false));
}
+static void readDmesg(LogAudit *al, LogKlog *kl) {
+ if (!al && !kl) {
+ return;
+ }
+
+ int len = klogctl(KLOG_SIZE_BUFFER, NULL, 0);
+ if (len <= 0) {
+ return;
+ }
+
+ len += 1024; // Margin for additional input race or trailing nul
+ std::unique_ptr<char []> buf(new char[len]);
+
+ int rc = klogctl(KLOG_READ_ALL, buf.get(), len);
+ if (rc <= 0) {
+ return;
+ }
+
+ if (rc < len) {
+ len = rc + 1;
+ }
+ buf[len - 1] = '\0';
+
+ if (kl) {
+ kl->synchronize(buf.get());
+ }
+
+ for (char *ptr = NULL, *tok = buf.get();
+ (rc >= 0) && ((tok = log_strtok_r(tok, &ptr)));
+ tok = NULL) {
+ if (al) {
+ rc = al->log(tok);
+ }
+ if (kl) {
+ rc = kl->log(tok);
+ }
+ }
+}
+
// Foreground waits for exit of the main persistent threads
// that are started here. The threads are created to manage
// UNIX domain client sockets for writing, reading and
@@ -410,41 +451,16 @@
kl = new LogKlog(logBuf, reader, fdDmesg, fdPmesg, al != NULL);
}
- if (al || kl) {
- int len = klogctl(KLOG_SIZE_BUFFER, NULL, 0);
- if (len > 0) {
- len++;
- char buf[len];
+ readDmesg(al, kl);
- int rc = klogctl(KLOG_READ_ALL, buf, len);
+ // failure is an option ... messages are in dmesg (required by standard)
- buf[len - 1] = '\0';
+ if (kl && kl->startListener()) {
+ delete kl;
+ }
- if ((rc >= 0) && kl) {
- kl->synchronize(buf);
- }
-
- for (char *ptr = NULL, *tok = buf;
- (rc >= 0) && ((tok = log_strtok_r(tok, &ptr)));
- tok = NULL) {
- if (al) {
- rc = al->log(tok);
- }
- if (kl) {
- rc = kl->log(tok);
- }
- }
- }
-
- // failure is an option ... messages are in dmesg (required by standard)
-
- if (kl && kl->startListener()) {
- delete kl;
- }
-
- if (al && al->startListener()) {
- delete al;
- }
+ if (al && al->startListener()) {
+ delete al;
}
TEMP_FAILURE_RETRY(pause());
