X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=liblttng-ustconsumer%2Flttng-ustconsumer.c;h=10213c1c97dcb8b4d93a80895a0e56d7ed9297db;hb=734f79bf717d87817623d382c59086dc9e8ef610;hp=f938d3548d9e8ed4ef049333efe1fc1aa16d1a0c;hpb=7ad0a0cb283d4004cf9274df8eec4e3530864fc7;p=lttng-tools.git

diff --git a/liblttng-ustconsumer/lttng-ustconsumer.c b/liblttng-ustconsumer/lttng-ustconsumer.c
index f938d3548..10213c1c9 100644
--- a/liblttng-ustconsumer/lttng-ustconsumer.c
+++ b/liblttng-ustconsumer/lttng-ustconsumer.c
@@ -34,6 +34,8 @@
 #include <lttng/ust-ctl.h>
 #include <lttngerr.h>
 
+#include "common/runas.h"
+
 extern struct lttng_consumer_global_data consumer_data;
 extern int consumer_poll_timeout;
 extern volatile int consumer_quit;
@@ -215,7 +217,9 @@ int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 				msg.u.stream.state,
 				msg.u.stream.mmap_len,
 				msg.u.stream.output,
-				msg.u.stream.path_name);
+				msg.u.stream.path_name,
+				msg.u.stream.uid,
+				msg.u.stream.gid);
 		if (new_stream == NULL) {
 			lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR);
 			goto end;
@@ -275,11 +279,8 @@ int lttng_ustconsumer_allocate_channel(struct lttng_consumer_channel *chan)
 	if (!chan->handle) {
 		return -ENOMEM;
 	}
-	/*
-	 * The channel fds are passed to ustctl, we only keep a copy.
-	 */
-	chan->shm_fd_is_copy = 1;
 	chan->wait_fd_is_copy = 1;
+	chan->shm_fd = -1;
 
 	return 0;
 }
@@ -287,6 +288,7 @@ int lttng_ustconsumer_allocate_channel(struct lttng_consumer_channel *chan)
 void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream *stream)
 {
 	ustctl_flush_buffer(stream->chan->handle, stream->buf, 0);
+	stream->hangup_flush_done = 1;
 }
 
 void lttng_ustconsumer_del_channel(struct lttng_consumer_channel *chan)
@@ -309,15 +311,14 @@ int lttng_ustconsumer_allocate_stream(struct lttng_consumer_stream *stream)
 	stream->buf = ustctl_open_stream_read(stream->chan->handle, stream->cpu);
 	if (!stream->buf)
 		return -EBUSY;
+	/* ustctl_open_stream_read has closed the shm fd. */
+	stream->wait_fd_is_copy = 1;
+	stream->shm_fd = -1;
+
 	stream->mmap_base = ustctl_get_mmap_base(stream->chan->handle, stream->buf);
 	if (!stream->mmap_base) {
 		return -EINVAL;
 	}
-	/*
-	 * The stream fds are passed to ustctl, we only keep a copy.
-	 */
-	stream->shm_fd_is_copy = 1;
-	stream->wait_fd_is_copy = 1;
 
 	return 0;
 }
@@ -343,12 +344,14 @@ int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
 		stream->wait_fd, stream->key);
 
 	/* We can consume the 1 byte written into the wait_fd by UST */
-	do {
-		readlen = read(stream->wait_fd, &dummy, 1);
-	} while (readlen == -1 && errno == -EINTR);
-	if (readlen == -1) {
-		ret = readlen;
-		goto end;
+	if (!stream->hangup_flush_done) {
+		do {
+			readlen = read(stream->wait_fd, &dummy, 1);
+		} while (readlen == -1 && errno == -EINTR);
+		if (readlen == -1) {
+			ret = readlen;
+			goto end;
+		}
 	}
 
 	buf = stream->buf;
@@ -356,7 +359,7 @@ int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
 	/* Get the next subbuffer */
 	err = ustctl_get_next_subbuf(handle, buf);
 	if (err != 0) {
-		ret = errno;
+		ret = -ret;	/* ustctl_get_next_subbuf returns negative, caller expect positive. */
 		/*
 		 * This is a debug message even for single-threaded consumer,
 		 * because poll() have more relaxed criterions than get subbuf,
@@ -370,11 +373,7 @@ int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
 	assert(stream->output == LTTNG_EVENT_MMAP);
 	/* read the used subbuffer size */
 	err = ustctl_get_padded_subbuf_size(handle, buf, &len);
-	if (err != 0) {
-		ret = errno;
-		perror("Getting sub-buffer len failed.");
-		goto end;
-	}
+	assert(err == 0);
 	/* write the subbuffer to the tracefile */
 	ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, len);
 	if (ret < 0) {
@@ -385,16 +384,7 @@ int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
 		ERR("Error writing to tracefile");
 	}
 	err = ustctl_put_next_subbuf(handle, buf);
-	if (err != 0) {
-		ret = errno;
-		if (errno == EFAULT) {
-			perror("Error in unreserving sub buffer\n");
-		} else if (errno == EIO) {
-			/* Should never happen with newer LTTng versions */
-			perror("Reader has been pushed by the writer, last sub-buffer corrupted.");
-		}
-		goto end;
-	}
+	assert(err == 0);
 end:
 	return ret;
 }
@@ -405,8 +395,10 @@ int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream *stream)
 
 	/* Opening the tracefile in write mode */
 	if (stream->path_name != NULL) {
-		ret = open(stream->path_name,
-				O_WRONLY|O_CREAT|O_TRUNC, S_IRWXU|S_IRWXG|S_IRWXO);
+		ret = run_as_open(stream->path_name,
+				O_WRONLY|O_CREAT|O_TRUNC,
+				S_IRWXU|S_IRWXG|S_IRWXO,
+				stream->uid, stream->gid);
 		if (ret < 0) {
 			ERR("Opening %s", stream->path_name);
 			perror("open");