Fix: ACCESS_ONCE() removed in kernel 4.15
[lttng-modules.git] / lib / ringbuffer / ring_buffer_frontend.c
index 0cd57581bb011168a351d044fe7fb739b536832c..4a8919b354ea1599ce9299d6b8f184d10d9f8dd9 100644 (file)
@@ -65,6 +65,7 @@
 #include <wrapper/kref.h>
 #include <wrapper/percpu-defs.h>
 #include <wrapper/timer.h>
+#include <wrapper/vmalloc.h>
 
 /*
  * Internal structure representing offsets to use at a sub-buffer switch.
@@ -147,8 +148,8 @@ void lib_ring_buffer_free(struct lib_ring_buffer *buf)
        struct channel *chan = buf->backend.chan;
 
        lib_ring_buffer_print_errors(chan, buf, buf->backend.cpu);
-       kfree(buf->commit_hot);
-       kfree(buf->commit_cold);
+       lttng_kvfree(buf->commit_hot);
+       lttng_kvfree(buf->commit_cold);
 
        lib_ring_buffer_backend_free(&buf->backend);
 }
@@ -245,7 +246,7 @@ int lib_ring_buffer_create(struct lib_ring_buffer *buf,
                return ret;
 
        buf->commit_hot =
-               kzalloc_node(ALIGN(sizeof(*buf->commit_hot)
+               lttng_kvzalloc_node(ALIGN(sizeof(*buf->commit_hot)
                                   * chan->backend.num_subbuf,
                                   1 << INTERNODE_CACHE_SHIFT),
                        GFP_KERNEL | __GFP_NOWARN,
@@ -256,7 +257,7 @@ int lib_ring_buffer_create(struct lib_ring_buffer *buf,
        }
 
        buf->commit_cold =
-               kzalloc_node(ALIGN(sizeof(*buf->commit_cold)
+               lttng_kvzalloc_node(ALIGN(sizeof(*buf->commit_cold)
                                   * chan->backend.num_subbuf,
                                   1 << INTERNODE_CACHE_SHIFT),
                        GFP_KERNEL | __GFP_NOWARN,
@@ -305,17 +306,17 @@ int lib_ring_buffer_create(struct lib_ring_buffer *buf,
 
        /* Error handling */
 free_init:
-       kfree(buf->commit_cold);
+       lttng_kvfree(buf->commit_cold);
 free_commit:
-       kfree(buf->commit_hot);
+       lttng_kvfree(buf->commit_hot);
 free_chanbuf:
        lib_ring_buffer_backend_free(&buf->backend);
        return ret;
 }
 
-static void switch_buffer_timer(unsigned long data)
+static void switch_buffer_timer(LTTNG_TIMER_FUNC_ARG_TYPE t)
 {
-       struct lib_ring_buffer *buf = (struct lib_ring_buffer *)data;
+       struct lib_ring_buffer *buf = lttng_from_timer(buf, t, switch_timer);
        struct channel *chan = buf->backend.chan;
        const struct lib_ring_buffer_config *config = &chan->backend.config;
 
@@ -340,22 +341,22 @@ static void lib_ring_buffer_start_switch_timer(struct lib_ring_buffer *buf)
 {
        struct channel *chan = buf->backend.chan;
        const struct lib_ring_buffer_config *config = &chan->backend.config;
+       unsigned int flags = 0;
 
        if (!chan->switch_timer_interval || buf->switch_timer_enabled)
                return;
 
        if (config->alloc == RING_BUFFER_ALLOC_PER_CPU)
-               lttng_init_timer_pinned(&buf->switch_timer);
-       else
-               init_timer(&buf->switch_timer);
+               flags = LTTNG_TIMER_PINNED;
 
-       buf->switch_timer.function = switch_buffer_timer;
+       lttng_timer_setup(&buf->switch_timer, switch_buffer_timer, flags, buf);
        buf->switch_timer.expires = jiffies + chan->switch_timer_interval;
-       buf->switch_timer.data = (unsigned long)buf;
+
        if (config->alloc == RING_BUFFER_ALLOC_PER_CPU)
                add_timer_on(&buf->switch_timer, buf->backend.cpu);
        else
                add_timer(&buf->switch_timer);
+
        buf->switch_timer_enabled = 1;
 }
 
@@ -376,9 +377,9 @@ static void lib_ring_buffer_stop_switch_timer(struct lib_ring_buffer *buf)
 /*
  * Polling timer to check the channels for data.
  */
-static void read_buffer_timer(unsigned long data)
+static void read_buffer_timer(LTTNG_TIMER_FUNC_ARG_TYPE t)
 {
-       struct lib_ring_buffer *buf = (struct lib_ring_buffer *)data;
+       struct lib_ring_buffer *buf = lttng_from_timer(buf, t, read_timer);
        struct channel *chan = buf->backend.chan;
        const struct lib_ring_buffer_config *config = &chan->backend.config;
 
@@ -405,6 +406,7 @@ static void lib_ring_buffer_start_read_timer(struct lib_ring_buffer *buf)
 {
        struct channel *chan = buf->backend.chan;
        const struct lib_ring_buffer_config *config = &chan->backend.config;
+       unsigned int flags;
 
        if (config->wakeup != RING_BUFFER_WAKEUP_BY_TIMER
            || !chan->read_timer_interval
@@ -412,18 +414,16 @@ static void lib_ring_buffer_start_read_timer(struct lib_ring_buffer *buf)
                return;
 
        if (config->alloc == RING_BUFFER_ALLOC_PER_CPU)
-               lttng_init_timer_pinned(&buf->read_timer);
-       else
-               init_timer(&buf->read_timer);
+               flags = LTTNG_TIMER_PINNED;
 
-       buf->read_timer.function = read_buffer_timer;
+       lttng_timer_setup(&buf->read_timer, read_buffer_timer, flags, buf);
        buf->read_timer.expires = jiffies + chan->read_timer_interval;
-       buf->read_timer.data = (unsigned long)buf;
 
        if (config->alloc == RING_BUFFER_ALLOC_PER_CPU)
                add_timer_on(&buf->read_timer, buf->backend.cpu);
        else
                add_timer(&buf->read_timer);
+
        buf->read_timer_enabled = 1;
 }
 
@@ -983,7 +983,7 @@ void *channel_destroy(struct channel *chan)
                         * Perform flush before writing to finalized.
                         */
                        smp_wmb();
-                       ACCESS_ONCE(buf->finalized) = 1;
+                       WRITE_ONCE(buf->finalized, 1);
                        wake_up_interruptible(&buf->read_wait);
                }
        } else {
@@ -997,10 +997,10 @@ void *channel_destroy(struct channel *chan)
                 * Perform flush before writing to finalized.
                 */
                smp_wmb();
-               ACCESS_ONCE(buf->finalized) = 1;
+               WRITE_ONCE(buf->finalized, 1);
                wake_up_interruptible(&buf->read_wait);
        }
-       ACCESS_ONCE(chan->finalized) = 1;
+       WRITE_ONCE(chan->finalized, 1);
        wake_up_interruptible(&chan->hp_wait);
        wake_up_interruptible(&chan->read_wait);
        priv = chan->backend.priv;
@@ -1077,7 +1077,7 @@ int lib_ring_buffer_snapshot(struct lib_ring_buffer *buf,
        int finalized;
 
 retry:
-       finalized = ACCESS_ONCE(buf->finalized);
+       finalized = READ_ONCE(buf->finalized);
        /*
         * Read finalized before counters.
         */
@@ -1248,7 +1248,7 @@ int lib_ring_buffer_get_subbuf(struct lib_ring_buffer *buf,
                return -EBUSY;
        }
 retry:
-       finalized = ACCESS_ONCE(buf->finalized);
+       finalized = READ_ONCE(buf->finalized);
        /*
         * Read finalized before counters.
         */
@@ -1884,16 +1884,14 @@ static void _lib_ring_buffer_switch_remote(struct lib_ring_buffer *buf,
        }
 
        /*
-        * Taking lock on CPU hotplug to ensure two things: first, that the
+        * Disabling preemption ensures two things: first, that the
         * target cpu is not taken concurrently offline while we are within
-        * smp_call_function_single() (I don't trust that get_cpu() on the
-        * _local_ CPU actually inhibit CPU hotplug for the _remote_ CPU (to be
-        * confirmed)). Secondly, if it happens that the CPU is not online, our
-        * own call to lib_ring_buffer_switch_slow() needs to be protected from
-        * CPU hotplug handlers, which can also perform a remote subbuffer
-        * switch.
+        * smp_call_function_single(). Secondly, if it happens that the
+        * CPU is not online, our own call to lib_ring_buffer_switch_slow()
+        * needs to be protected from CPU hotplug handlers, which can
+        * also perform a remote subbuffer switch.
         */
-       get_online_cpus();
+       preempt_disable();
        param.buf = buf;
        param.mode = mode;
        ret = smp_call_function_single(buf->backend.cpu,
@@ -1902,7 +1900,7 @@ static void _lib_ring_buffer_switch_remote(struct lib_ring_buffer *buf,
                /* Remote CPU is offline, do it ourself. */
                lib_ring_buffer_switch_slow(buf, mode);
        }
-       put_online_cpus();
+       preempt_enable();
 }
 
 /* Switch sub-buffer if current sub-buffer is non-empty. */
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