[ANNOUNCE] v5.6.14-rt7

[ANNOUNCE] v5.6.14-rt7

[Sebastian Andrzej Siewior]

Dear RT folks!

I'm pleased to announce the v5.6.14-rt7 patch set. 

Changes since v5.6.14-rt6:

  - 汪勇 sent a patch to not lose a line break on pr_cont() if
    requested.

  - A few missing locking spots were identified in the zswap patch while
    it was reworked for upstream. Changes have been integrated in the
    original patch.

Known issues
     - It has been pointed out that due to changes to the printk code the
       internal buffer representation changed. This is only an issue if tools
       like `crash' are used to extract the printk buffer from a kernel memory
       image.

The delta patch against v5.6.14-rt6 is appended below and can be found here:
 
     https://cdn.kernel.org/pub/linux/kernel/projects/rt/5.6/incr/patch-5.6.14-rt6-rt7.patch.xz

You can get this release via the git tree at:

    git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git v5.6.14-rt7

The RT patch against v5.6.14 can be found here:

    https://cdn.kernel.org/pub/linux/kernel/projects/rt/5.6/older/patch-5.6.14-rt7.patch.xz

The split quilt queue is available at:

    https://cdn.kernel.org/pub/linux/kernel/projects/rt/5.6/older/patches-5.6.14-rt7.tar.xz

Sebastian

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 8bc683be08574..6296d348f3008 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1871,6 +1871,7 @@ static void cont_add(int ctx, int cpu, u32 caller_id, int facility, int level,
 	// but later continuations can add a newline.
 	if (flags & LOG_NEWLINE) {
 		c->flags |= LOG_NEWLINE;
+		cont_flush(ctx);
 	}
 }
 
diff --git a/localversion-rt b/localversion-rt
index 8fc605d806670..045478966e9f1 100644
--- a/localversion-rt
+++ b/localversion-rt
@@ -1 +1 @@
--rt6
+-rt7
diff --git a/mm/zswap.c b/mm/zswap.c
index 1591b5d37f65d..51944e98c1249 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -391,6 +391,8 @@ static struct zswap_entry *zswap_entry_find_get(struct rb_root *root,
 * per-cpu code
 **********************************/
 static DEFINE_PER_CPU(u8 *, zswap_dstmem);
+/* Used for zswap_dstmem and tfm */
+static DEFINE_LOCAL_IRQ_LOCK(zswap_cpu_lock);
 
 static int zswap_dstmem_prepare(unsigned int cpu)
 {
@@ -920,10 +922,11 @@ static int zswap_writeback_entry(struct zpool *pool, unsigned long handle)
 		dlen = PAGE_SIZE;
 		src = (u8 *)zhdr + sizeof(struct zswap_header);
 		dst = kmap_atomic(page);
-		tfm = *get_cpu_ptr(entry->pool->tfm);
+		local_lock(zswap_cpu_lock);
+		tfm = *this_cpu_ptr(entry->pool->tfm);
 		ret = crypto_comp_decompress(tfm, src, entry->length,
 					     dst, &dlen);
-		put_cpu_ptr(entry->pool->tfm);
+		local_unlock(zswap_cpu_lock);
 		kunmap_atomic(dst);
 		BUG_ON(ret);
 		BUG_ON(dlen != PAGE_SIZE);
@@ -996,8 +999,6 @@ static void zswap_fill_page(void *ptr, unsigned long value)
 	memset_l(page, value, PAGE_SIZE / sizeof(unsigned long));
 }
 
-/* protect zswap_dstmem from concurrency */
-static DEFINE_LOCAL_IRQ_LOCK(zswap_dstmem_lock);
 /*********************************
 * frontswap hooks
 **********************************/
@@ -1077,7 +1078,8 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset,
 	}
 
 	/* compress */
-	dst = get_locked_var(zswap_dstmem_lock, zswap_dstmem);
+	local_lock(zswap_cpu_lock);
+	dst = *this_cpu_ptr(&zswap_dstmem);
 	tfm = *this_cpu_ptr(entry->pool->tfm);
 	src = kmap_atomic(page);
 	ret = crypto_comp_compress(tfm, src, PAGE_SIZE, dst, &dlen);
@@ -1105,7 +1107,7 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset,
 	memcpy(buf, &zhdr, hlen);
 	memcpy(buf + hlen, dst, dlen);
 	zpool_unmap_handle(entry->pool->zpool, handle);
-	put_locked_var(zswap_dstmem_lock, zswap_dstmem);
+	local_unlock(zswap_cpu_lock);
 
 	/* populate entry */
 	entry->offset = offset;
@@ -1133,7 +1135,7 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset,
 	return 0;
 
 put_dstmem:
-	put_locked_var(zswap_dstmem_lock, zswap_dstmem);
+	local_unlock(zswap_cpu_lock);
 	zswap_pool_put(entry->pool);
 freepage:
 	zswap_entry_cache_free(entry);
@@ -1178,9 +1180,10 @@ static int zswap_frontswap_load(unsigned type, pgoff_t offset,
 	if (zpool_evictable(entry->pool->zpool))
 		src += sizeof(struct zswap_header);
 	dst = kmap_atomic(page);
-	tfm = *get_cpu_ptr(entry->pool->tfm);
+	local_lock(zswap_cpu_lock);
+	tfm = *this_cpu_ptr(entry->pool->tfm);
 	ret = crypto_comp_decompress(tfm, src, entry->length, dst, &dlen);
-	put_cpu_ptr(entry->pool->tfm);
+	local_unlock(zswap_cpu_lock);
 	kunmap_atomic(dst);
 	zpool_unmap_handle(entry->pool->zpool, entry->handle);
 	BUG_ON(ret);