Fix: kernel ctl error codes are based on errno

[lttng-tools.git] / src / common / kernel-consumer / kernel-consumer.c

diff --git a/src/common/kernel-consumer/kernel-consumer.c b/src/common/kernel-consumer/kernel-consumer.c
index 1a44ce152694da52e4f11688aef61780b6193b48..ea6237959c107c6db70a4f47c66fc3b08837b8d8 100644 (file)
--- a/src/common/kernel-consumer/kernel-consumer.c
+++ b/src/common/kernel-consumer/kernel-consumer.c
@@ -56,8 +56,8 @@ int lttng_kconsumer_take_snapshot(struct lttng_consumer_stream *stream)
 
        ret = kernctl_snapshot(infd);
        if (ret != 0) {
-               errno = -ret;
                perror("Getting sub-buffer snapshot.");
+               ret = -errno;
        }
 
        return ret;
@@ -76,8 +76,8 @@ int lttng_kconsumer_get_produced_snapshot(struct lttng_consumer_stream *stream,
 
        ret = kernctl_snapshot_get_produced(infd, pos);
        if (ret != 0) {
-               errno = -ret;
                perror("kernctl_snapshot_get_produced");
+               ret = -errno;
        }
 
        return ret;
@@ -452,7 +452,6 @@ ssize_t lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
        /* Get the next subbuffer */
        err = kernctl_get_next_subbuf(infd);
        if (err != 0) {
-               ret = err;
                /*
                 * This is a debug message even for single-threaded consumer,
                 * because poll() have more relaxed criterions than get subbuf,
@@ -461,15 +460,15 @@ ssize_t lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
                 */
                DBG("Reserving sub buffer failed (everything is normal, "
                                "it is due to concurrency)");
+               ret = -errno;
                goto end;
        }
 
        /* Get the full subbuffer size including padding */
        err = kernctl_get_padded_subbuf_size(infd, &len);
        if (err != 0) {
-               errno = -err;
                perror("Getting sub-buffer len failed.");
-               ret = err;
+               ret = -errno;
                goto end;
        }
 
@@ -504,9 +503,8 @@ ssize_t lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
                /* Get subbuffer size without padding */
                err = kernctl_get_subbuf_size(infd, &subbuf_size);
                if (err != 0) {
-                       errno = -err;
                        perror("Getting sub-buffer len failed.");
-                       ret = err;
+                       ret = -errno;
                        goto end;
                }
 
@@ -536,20 +534,18 @@ ssize_t lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
                break;
        default:
                ERR("Unknown output method");
-               ret = -1;
+               ret = -EPERM;
        }
 
        err = kernctl_put_next_subbuf(infd);
        if (err != 0) {
-               errno = -err;
                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.");
                }
-
-               ret = -err;
+               ret = -errno;
                goto end;
        }
 
@@ -581,8 +577,8 @@ int lttng_kconsumer_on_recv_stream(struct lttng_consumer_stream *stream)
 
                ret = kernctl_get_mmap_len(stream->wait_fd, &mmap_len);
                if (ret != 0) {
-                       errno = -ret;
                        PERROR("kernctl_get_mmap_len");
+                       ret = -errno;
                        goto error_close_fd;
                }
                stream->mmap_len = (size_t) mmap_len;