The patch below does not apply to the 3.18-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 251b7aea34ba3c4d4fdfa9447695642eb8b8b098 Mon Sep 17 00:00:00 2001
From: Eric Biggers <ebiggers(a)google.com>
Date: Thu, 3 Jan 2019 20:16:13 -0800
Subject: [PATCH] crypto: pcbc - remove bogus memcpy()s with src == dest
The memcpy()s in the PCBC implementation use walk->iv as both the source
and destination, which has undefined behavior. These memcpy()'s are
actually unneeded, because walk->iv is already used to hold the previous
plaintext block XOR'd with the previous ciphertext block. Thus,
walk->iv is already updated to its final value.
So remove the broken and unnecessary memcpy()s.
Fixes: 91652be5d1b9 ("[CRYPTO] pcbc: Add Propagated CBC template")
Cc: <stable(a)vger.kernel.org> # v2.6.21+
Cc: David Howells <dhowells(a)redhat.com>
Signed-off-by: Eric Biggers <ebiggers(a)google.com>
Signed-off-by: Herbert Xu <herbert(a)gondor.apana.org.au>
diff --git a/crypto/pcbc.c b/crypto/pcbc.c
index 8aa10144407c..1b182dfedc94 100644
--- a/crypto/pcbc.c
+++ b/crypto/pcbc.c
@@ -51,7 +51,7 @@ static int crypto_pcbc_encrypt_segment(struct skcipher_request *req,
unsigned int nbytes = walk->nbytes;
u8 *src = walk->src.virt.addr;
u8 *dst = walk->dst.virt.addr;
- u8 *iv = walk->iv;
+ u8 * const iv = walk->iv;
do {
crypto_xor(iv, src, bsize);
@@ -72,7 +72,7 @@ static int crypto_pcbc_encrypt_inplace(struct skcipher_request *req,
int bsize = crypto_cipher_blocksize(tfm);
unsigned int nbytes = walk->nbytes;
u8 *src = walk->src.virt.addr;
- u8 *iv = walk->iv;
+ u8 * const iv = walk->iv;
u8 tmpbuf[MAX_CIPHER_BLOCKSIZE];
do {
@@ -84,8 +84,6 @@ static int crypto_pcbc_encrypt_inplace(struct skcipher_request *req,
src += bsize;
} while ((nbytes -= bsize) >= bsize);
- memcpy(walk->iv, iv, bsize);
-
return nbytes;
}
@@ -121,7 +119,7 @@ static int crypto_pcbc_decrypt_segment(struct skcipher_request *req,
unsigned int nbytes = walk->nbytes;
u8 *src = walk->src.virt.addr;
u8 *dst = walk->dst.virt.addr;
- u8 *iv = walk->iv;
+ u8 * const iv = walk->iv;
do {
crypto_cipher_decrypt_one(tfm, dst, src);
@@ -132,8 +130,6 @@ static int crypto_pcbc_decrypt_segment(struct skcipher_request *req,
dst += bsize;
} while ((nbytes -= bsize) >= bsize);
- memcpy(walk->iv, iv, bsize);
-
return nbytes;
}
@@ -144,7 +140,7 @@ static int crypto_pcbc_decrypt_inplace(struct skcipher_request *req,
int bsize = crypto_cipher_blocksize(tfm);
unsigned int nbytes = walk->nbytes;
u8 *src = walk->src.virt.addr;
- u8 *iv = walk->iv;
+ u8 * const iv = walk->iv;
u8 tmpbuf[MAX_CIPHER_BLOCKSIZE] __aligned(__alignof__(u32));
do {
@@ -156,8 +152,6 @@ static int crypto_pcbc_decrypt_inplace(struct skcipher_request *req,
src += bsize;
} while ((nbytes -= bsize) >= bsize);
- memcpy(walk->iv, iv, bsize);
-
return nbytes;
}
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From b89f6d1fcb30a8cbdc18ce00c7d93792076af453 Mon Sep 17 00:00:00 2001
From: Filipe Manana <fdmanana(a)suse.com>
Date: Thu, 13 Dec 2018 21:16:45 +0000
Subject: [PATCH] Btrfs: setup a nofs context for memory allocation at
btrfs_create_tree()
We are holding a transaction handle when creating a tree, therefore we can
not allocate the root using GFP_KERNEL, as we could deadlock if reclaim is
triggered by the allocation, therefore setup a nofs context.
Fixes: 74e4d82757f74 ("btrfs: let callers of btrfs_alloc_root pass gfp flags")
CC: stable(a)vger.kernel.org # 4.9+
Reviewed-by: Nikolay Borisov <nborisov(a)suse.com>
Signed-off-by: Filipe Manana <fdmanana(a)suse.com>
Reviewed-by: David Sterba <dsterba(a)suse.com>
Signed-off-by: David Sterba <dsterba(a)suse.com>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 6a2a2a951705..888d72dda794 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -17,6 +17,7 @@
#include <linux/semaphore.h>
#include <linux/error-injection.h>
#include <linux/crc32c.h>
+#include <linux/sched/mm.h>
#include <asm/unaligned.h>
#include "ctree.h"
#include "disk-io.h"
@@ -1258,10 +1259,17 @@ struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *tree_root = fs_info->tree_root;
struct btrfs_root *root;
struct btrfs_key key;
+ unsigned int nofs_flag;
int ret = 0;
uuid_le uuid = NULL_UUID_LE;
+ /*
+ * We're holding a transaction handle, so use a NOFS memory allocation
+ * context to avoid deadlock if reclaim happens.
+ */
+ nofs_flag = memalloc_nofs_save();
root = btrfs_alloc_root(fs_info, GFP_KERNEL);
+ memalloc_nofs_restore(nofs_flag);
if (!root)
return ERR_PTR(-ENOMEM);
The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From b89f6d1fcb30a8cbdc18ce00c7d93792076af453 Mon Sep 17 00:00:00 2001
From: Filipe Manana <fdmanana(a)suse.com>
Date: Thu, 13 Dec 2018 21:16:45 +0000
Subject: [PATCH] Btrfs: setup a nofs context for memory allocation at
btrfs_create_tree()
We are holding a transaction handle when creating a tree, therefore we can
not allocate the root using GFP_KERNEL, as we could deadlock if reclaim is
triggered by the allocation, therefore setup a nofs context.
Fixes: 74e4d82757f74 ("btrfs: let callers of btrfs_alloc_root pass gfp flags")
CC: stable(a)vger.kernel.org # 4.9+
Reviewed-by: Nikolay Borisov <nborisov(a)suse.com>
Signed-off-by: Filipe Manana <fdmanana(a)suse.com>
Reviewed-by: David Sterba <dsterba(a)suse.com>
Signed-off-by: David Sterba <dsterba(a)suse.com>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 6a2a2a951705..888d72dda794 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -17,6 +17,7 @@
#include <linux/semaphore.h>
#include <linux/error-injection.h>
#include <linux/crc32c.h>
+#include <linux/sched/mm.h>
#include <asm/unaligned.h>
#include "ctree.h"
#include "disk-io.h"
@@ -1258,10 +1259,17 @@ struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *tree_root = fs_info->tree_root;
struct btrfs_root *root;
struct btrfs_key key;
+ unsigned int nofs_flag;
int ret = 0;
uuid_le uuid = NULL_UUID_LE;
+ /*
+ * We're holding a transaction handle, so use a NOFS memory allocation
+ * context to avoid deadlock if reclaim happens.
+ */
+ nofs_flag = memalloc_nofs_save();
root = btrfs_alloc_root(fs_info, GFP_KERNEL);
+ memalloc_nofs_restore(nofs_flag);
if (!root)
return ERR_PTR(-ENOMEM);
The patch below does not apply to the 3.18-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 1d1f898df6586c5ea9aeaf349f13089c6fa37903 Mon Sep 17 00:00:00 2001
From: "Zhang, Jun" <jun.zhang(a)intel.com>
Date: Tue, 18 Dec 2018 06:55:01 -0800
Subject: [PATCH] rcu: Do RCU GP kthread self-wakeup from softirq and interrupt
The rcu_gp_kthread_wake() function is invoked when it might be necessary
to wake the RCU grace-period kthread. Because self-wakeups are normally
a useless waste of CPU cycles, if rcu_gp_kthread_wake() is invoked from
this kthread, it naturally refuses to do the wakeup.
Unfortunately, natural though it might be, this heuristic fails when
rcu_gp_kthread_wake() is invoked from an interrupt or softirq handler
that interrupted the grace-period kthread just after the final check of
the wait-event condition but just before the schedule() call. In this
case, a wakeup is required, even though the call to rcu_gp_kthread_wake()
is within the RCU grace-period kthread's context. Failing to provide
this wakeup can result in grace periods failing to start, which in turn
results in out-of-memory conditions.
This race window is quite narrow, but it actually did happen during real
testing. It would of course need to be fixed even if it was strictly
theoretical in nature.
This patch does not Cc stable because it does not apply cleanly to
earlier kernel versions.
Fixes: 48a7639ce80c ("rcu: Make callers awaken grace-period kthread")
Reported-by: "He, Bo" <bo.he(a)intel.com>
Co-developed-by: "Zhang, Jun" <jun.zhang(a)intel.com>
Co-developed-by: "He, Bo" <bo.he(a)intel.com>
Co-developed-by: "xiao, jin" <jin.xiao(a)intel.com>
Co-developed-by: Bai, Jie A <jie.a.bai(a)intel.com>
Signed-off: "Zhang, Jun" <jun.zhang(a)intel.com>
Signed-off: "He, Bo" <bo.he(a)intel.com>
Signed-off: "xiao, jin" <jin.xiao(a)intel.com>
Signed-off: Bai, Jie A <jie.a.bai(a)intel.com>
Signed-off-by: "Zhang, Jun" <jun.zhang(a)intel.com>
[ paulmck: Switch from !in_softirq() to "!in_interrupt() &&
!in_serving_softirq() to avoid redundant wakeups and to also handle the
interrupt-handler scenario as well as the softirq-handler scenario that
actually occurred in testing. ]
Signed-off-by: Paul E. McKenney <paulmck(a)linux.ibm.com>
Link: https://lkml.kernel.org/r/CD6925E8781EFD4D8E11882D20FC406D52A11F61@SHSMSX10…
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 9ceb93f848cd..21775eebb8f0 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1593,15 +1593,23 @@ static bool rcu_future_gp_cleanup(struct rcu_node *rnp)
}
/*
- * Awaken the grace-period kthread. Don't do a self-awaken, and don't
- * bother awakening when there is nothing for the grace-period kthread
- * to do (as in several CPUs raced to awaken, and we lost), and finally
- * don't try to awaken a kthread that has not yet been created. If
- * all those checks are passed, track some debug information and awaken.
+ * Awaken the grace-period kthread. Don't do a self-awaken (unless in
+ * an interrupt or softirq handler), and don't bother awakening when there
+ * is nothing for the grace-period kthread to do (as in several CPUs raced
+ * to awaken, and we lost), and finally don't try to awaken a kthread that
+ * has not yet been created. If all those checks are passed, track some
+ * debug information and awaken.
+ *
+ * So why do the self-wakeup when in an interrupt or softirq handler
+ * in the grace-period kthread's context? Because the kthread might have
+ * been interrupted just as it was going to sleep, and just after the final
+ * pre-sleep check of the awaken condition. In this case, a wakeup really
+ * is required, and is therefore supplied.
*/
static void rcu_gp_kthread_wake(void)
{
- if (current == rcu_state.gp_kthread ||
+ if ((current == rcu_state.gp_kthread &&
+ !in_interrupt() && !in_serving_softirq()) ||
!READ_ONCE(rcu_state.gp_flags) ||
!rcu_state.gp_kthread)
return;
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 1d1f898df6586c5ea9aeaf349f13089c6fa37903 Mon Sep 17 00:00:00 2001
From: "Zhang, Jun" <jun.zhang(a)intel.com>
Date: Tue, 18 Dec 2018 06:55:01 -0800
Subject: [PATCH] rcu: Do RCU GP kthread self-wakeup from softirq and interrupt
The rcu_gp_kthread_wake() function is invoked when it might be necessary
to wake the RCU grace-period kthread. Because self-wakeups are normally
a useless waste of CPU cycles, if rcu_gp_kthread_wake() is invoked from
this kthread, it naturally refuses to do the wakeup.
Unfortunately, natural though it might be, this heuristic fails when
rcu_gp_kthread_wake() is invoked from an interrupt or softirq handler
that interrupted the grace-period kthread just after the final check of
the wait-event condition but just before the schedule() call. In this
case, a wakeup is required, even though the call to rcu_gp_kthread_wake()
is within the RCU grace-period kthread's context. Failing to provide
this wakeup can result in grace periods failing to start, which in turn
results in out-of-memory conditions.
This race window is quite narrow, but it actually did happen during real
testing. It would of course need to be fixed even if it was strictly
theoretical in nature.
This patch does not Cc stable because it does not apply cleanly to
earlier kernel versions.
Fixes: 48a7639ce80c ("rcu: Make callers awaken grace-period kthread")
Reported-by: "He, Bo" <bo.he(a)intel.com>
Co-developed-by: "Zhang, Jun" <jun.zhang(a)intel.com>
Co-developed-by: "He, Bo" <bo.he(a)intel.com>
Co-developed-by: "xiao, jin" <jin.xiao(a)intel.com>
Co-developed-by: Bai, Jie A <jie.a.bai(a)intel.com>
Signed-off: "Zhang, Jun" <jun.zhang(a)intel.com>
Signed-off: "He, Bo" <bo.he(a)intel.com>
Signed-off: "xiao, jin" <jin.xiao(a)intel.com>
Signed-off: Bai, Jie A <jie.a.bai(a)intel.com>
Signed-off-by: "Zhang, Jun" <jun.zhang(a)intel.com>
[ paulmck: Switch from !in_softirq() to "!in_interrupt() &&
!in_serving_softirq() to avoid redundant wakeups and to also handle the
interrupt-handler scenario as well as the softirq-handler scenario that
actually occurred in testing. ]
Signed-off-by: Paul E. McKenney <paulmck(a)linux.ibm.com>
Link: https://lkml.kernel.org/r/CD6925E8781EFD4D8E11882D20FC406D52A11F61@SHSMSX10…
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 9ceb93f848cd..21775eebb8f0 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1593,15 +1593,23 @@ static bool rcu_future_gp_cleanup(struct rcu_node *rnp)
}
/*
- * Awaken the grace-period kthread. Don't do a self-awaken, and don't
- * bother awakening when there is nothing for the grace-period kthread
- * to do (as in several CPUs raced to awaken, and we lost), and finally
- * don't try to awaken a kthread that has not yet been created. If
- * all those checks are passed, track some debug information and awaken.
+ * Awaken the grace-period kthread. Don't do a self-awaken (unless in
+ * an interrupt or softirq handler), and don't bother awakening when there
+ * is nothing for the grace-period kthread to do (as in several CPUs raced
+ * to awaken, and we lost), and finally don't try to awaken a kthread that
+ * has not yet been created. If all those checks are passed, track some
+ * debug information and awaken.
+ *
+ * So why do the self-wakeup when in an interrupt or softirq handler
+ * in the grace-period kthread's context? Because the kthread might have
+ * been interrupted just as it was going to sleep, and just after the final
+ * pre-sleep check of the awaken condition. In this case, a wakeup really
+ * is required, and is therefore supplied.
*/
static void rcu_gp_kthread_wake(void)
{
- if (current == rcu_state.gp_kthread ||
+ if ((current == rcu_state.gp_kthread &&
+ !in_interrupt() && !in_serving_softirq()) ||
!READ_ONCE(rcu_state.gp_flags) ||
!rcu_state.gp_kthread)
return;
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 1d1f898df6586c5ea9aeaf349f13089c6fa37903 Mon Sep 17 00:00:00 2001
From: "Zhang, Jun" <jun.zhang(a)intel.com>
Date: Tue, 18 Dec 2018 06:55:01 -0800
Subject: [PATCH] rcu: Do RCU GP kthread self-wakeup from softirq and interrupt
The rcu_gp_kthread_wake() function is invoked when it might be necessary
to wake the RCU grace-period kthread. Because self-wakeups are normally
a useless waste of CPU cycles, if rcu_gp_kthread_wake() is invoked from
this kthread, it naturally refuses to do the wakeup.
Unfortunately, natural though it might be, this heuristic fails when
rcu_gp_kthread_wake() is invoked from an interrupt or softirq handler
that interrupted the grace-period kthread just after the final check of
the wait-event condition but just before the schedule() call. In this
case, a wakeup is required, even though the call to rcu_gp_kthread_wake()
is within the RCU grace-period kthread's context. Failing to provide
this wakeup can result in grace periods failing to start, which in turn
results in out-of-memory conditions.
This race window is quite narrow, but it actually did happen during real
testing. It would of course need to be fixed even if it was strictly
theoretical in nature.
This patch does not Cc stable because it does not apply cleanly to
earlier kernel versions.
Fixes: 48a7639ce80c ("rcu: Make callers awaken grace-period kthread")
Reported-by: "He, Bo" <bo.he(a)intel.com>
Co-developed-by: "Zhang, Jun" <jun.zhang(a)intel.com>
Co-developed-by: "He, Bo" <bo.he(a)intel.com>
Co-developed-by: "xiao, jin" <jin.xiao(a)intel.com>
Co-developed-by: Bai, Jie A <jie.a.bai(a)intel.com>
Signed-off: "Zhang, Jun" <jun.zhang(a)intel.com>
Signed-off: "He, Bo" <bo.he(a)intel.com>
Signed-off: "xiao, jin" <jin.xiao(a)intel.com>
Signed-off: Bai, Jie A <jie.a.bai(a)intel.com>
Signed-off-by: "Zhang, Jun" <jun.zhang(a)intel.com>
[ paulmck: Switch from !in_softirq() to "!in_interrupt() &&
!in_serving_softirq() to avoid redundant wakeups and to also handle the
interrupt-handler scenario as well as the softirq-handler scenario that
actually occurred in testing. ]
Signed-off-by: Paul E. McKenney <paulmck(a)linux.ibm.com>
Link: https://lkml.kernel.org/r/CD6925E8781EFD4D8E11882D20FC406D52A11F61@SHSMSX10…
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 9ceb93f848cd..21775eebb8f0 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1593,15 +1593,23 @@ static bool rcu_future_gp_cleanup(struct rcu_node *rnp)
}
/*
- * Awaken the grace-period kthread. Don't do a self-awaken, and don't
- * bother awakening when there is nothing for the grace-period kthread
- * to do (as in several CPUs raced to awaken, and we lost), and finally
- * don't try to awaken a kthread that has not yet been created. If
- * all those checks are passed, track some debug information and awaken.
+ * Awaken the grace-period kthread. Don't do a self-awaken (unless in
+ * an interrupt or softirq handler), and don't bother awakening when there
+ * is nothing for the grace-period kthread to do (as in several CPUs raced
+ * to awaken, and we lost), and finally don't try to awaken a kthread that
+ * has not yet been created. If all those checks are passed, track some
+ * debug information and awaken.
+ *
+ * So why do the self-wakeup when in an interrupt or softirq handler
+ * in the grace-period kthread's context? Because the kthread might have
+ * been interrupted just as it was going to sleep, and just after the final
+ * pre-sleep check of the awaken condition. In this case, a wakeup really
+ * is required, and is therefore supplied.
*/
static void rcu_gp_kthread_wake(void)
{
- if (current == rcu_state.gp_kthread ||
+ if ((current == rcu_state.gp_kthread &&
+ !in_interrupt() && !in_serving_softirq()) ||
!READ_ONCE(rcu_state.gp_flags) ||
!rcu_state.gp_kthread)
return;
The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 1d1f898df6586c5ea9aeaf349f13089c6fa37903 Mon Sep 17 00:00:00 2001
From: "Zhang, Jun" <jun.zhang(a)intel.com>
Date: Tue, 18 Dec 2018 06:55:01 -0800
Subject: [PATCH] rcu: Do RCU GP kthread self-wakeup from softirq and interrupt
The rcu_gp_kthread_wake() function is invoked when it might be necessary
to wake the RCU grace-period kthread. Because self-wakeups are normally
a useless waste of CPU cycles, if rcu_gp_kthread_wake() is invoked from
this kthread, it naturally refuses to do the wakeup.
Unfortunately, natural though it might be, this heuristic fails when
rcu_gp_kthread_wake() is invoked from an interrupt or softirq handler
that interrupted the grace-period kthread just after the final check of
the wait-event condition but just before the schedule() call. In this
case, a wakeup is required, even though the call to rcu_gp_kthread_wake()
is within the RCU grace-period kthread's context. Failing to provide
this wakeup can result in grace periods failing to start, which in turn
results in out-of-memory conditions.
This race window is quite narrow, but it actually did happen during real
testing. It would of course need to be fixed even if it was strictly
theoretical in nature.
This patch does not Cc stable because it does not apply cleanly to
earlier kernel versions.
Fixes: 48a7639ce80c ("rcu: Make callers awaken grace-period kthread")
Reported-by: "He, Bo" <bo.he(a)intel.com>
Co-developed-by: "Zhang, Jun" <jun.zhang(a)intel.com>
Co-developed-by: "He, Bo" <bo.he(a)intel.com>
Co-developed-by: "xiao, jin" <jin.xiao(a)intel.com>
Co-developed-by: Bai, Jie A <jie.a.bai(a)intel.com>
Signed-off: "Zhang, Jun" <jun.zhang(a)intel.com>
Signed-off: "He, Bo" <bo.he(a)intel.com>
Signed-off: "xiao, jin" <jin.xiao(a)intel.com>
Signed-off: Bai, Jie A <jie.a.bai(a)intel.com>
Signed-off-by: "Zhang, Jun" <jun.zhang(a)intel.com>
[ paulmck: Switch from !in_softirq() to "!in_interrupt() &&
!in_serving_softirq() to avoid redundant wakeups and to also handle the
interrupt-handler scenario as well as the softirq-handler scenario that
actually occurred in testing. ]
Signed-off-by: Paul E. McKenney <paulmck(a)linux.ibm.com>
Link: https://lkml.kernel.org/r/CD6925E8781EFD4D8E11882D20FC406D52A11F61@SHSMSX10…
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 9ceb93f848cd..21775eebb8f0 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1593,15 +1593,23 @@ static bool rcu_future_gp_cleanup(struct rcu_node *rnp)
}
/*
- * Awaken the grace-period kthread. Don't do a self-awaken, and don't
- * bother awakening when there is nothing for the grace-period kthread
- * to do (as in several CPUs raced to awaken, and we lost), and finally
- * don't try to awaken a kthread that has not yet been created. If
- * all those checks are passed, track some debug information and awaken.
+ * Awaken the grace-period kthread. Don't do a self-awaken (unless in
+ * an interrupt or softirq handler), and don't bother awakening when there
+ * is nothing for the grace-period kthread to do (as in several CPUs raced
+ * to awaken, and we lost), and finally don't try to awaken a kthread that
+ * has not yet been created. If all those checks are passed, track some
+ * debug information and awaken.
+ *
+ * So why do the self-wakeup when in an interrupt or softirq handler
+ * in the grace-period kthread's context? Because the kthread might have
+ * been interrupted just as it was going to sleep, and just after the final
+ * pre-sleep check of the awaken condition. In this case, a wakeup really
+ * is required, and is therefore supplied.
*/
static void rcu_gp_kthread_wake(void)
{
- if (current == rcu_state.gp_kthread ||
+ if ((current == rcu_state.gp_kthread &&
+ !in_interrupt() && !in_serving_softirq()) ||
!READ_ONCE(rcu_state.gp_flags) ||
!rcu_state.gp_kthread)
return;
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 251b7aea34ba3c4d4fdfa9447695642eb8b8b098 Mon Sep 17 00:00:00 2001
From: Eric Biggers <ebiggers(a)google.com>
Date: Thu, 3 Jan 2019 20:16:13 -0800
Subject: [PATCH] crypto: pcbc - remove bogus memcpy()s with src == dest
The memcpy()s in the PCBC implementation use walk->iv as both the source
and destination, which has undefined behavior. These memcpy()'s are
actually unneeded, because walk->iv is already used to hold the previous
plaintext block XOR'd with the previous ciphertext block. Thus,
walk->iv is already updated to its final value.
So remove the broken and unnecessary memcpy()s.
Fixes: 91652be5d1b9 ("[CRYPTO] pcbc: Add Propagated CBC template")
Cc: <stable(a)vger.kernel.org> # v2.6.21+
Cc: David Howells <dhowells(a)redhat.com>
Signed-off-by: Eric Biggers <ebiggers(a)google.com>
Signed-off-by: Herbert Xu <herbert(a)gondor.apana.org.au>
diff --git a/crypto/pcbc.c b/crypto/pcbc.c
index 8aa10144407c..1b182dfedc94 100644
--- a/crypto/pcbc.c
+++ b/crypto/pcbc.c
@@ -51,7 +51,7 @@ static int crypto_pcbc_encrypt_segment(struct skcipher_request *req,
unsigned int nbytes = walk->nbytes;
u8 *src = walk->src.virt.addr;
u8 *dst = walk->dst.virt.addr;
- u8 *iv = walk->iv;
+ u8 * const iv = walk->iv;
do {
crypto_xor(iv, src, bsize);
@@ -72,7 +72,7 @@ static int crypto_pcbc_encrypt_inplace(struct skcipher_request *req,
int bsize = crypto_cipher_blocksize(tfm);
unsigned int nbytes = walk->nbytes;
u8 *src = walk->src.virt.addr;
- u8 *iv = walk->iv;
+ u8 * const iv = walk->iv;
u8 tmpbuf[MAX_CIPHER_BLOCKSIZE];
do {
@@ -84,8 +84,6 @@ static int crypto_pcbc_encrypt_inplace(struct skcipher_request *req,
src += bsize;
} while ((nbytes -= bsize) >= bsize);
- memcpy(walk->iv, iv, bsize);
-
return nbytes;
}
@@ -121,7 +119,7 @@ static int crypto_pcbc_decrypt_segment(struct skcipher_request *req,
unsigned int nbytes = walk->nbytes;
u8 *src = walk->src.virt.addr;
u8 *dst = walk->dst.virt.addr;
- u8 *iv = walk->iv;
+ u8 * const iv = walk->iv;
do {
crypto_cipher_decrypt_one(tfm, dst, src);
@@ -132,8 +130,6 @@ static int crypto_pcbc_decrypt_segment(struct skcipher_request *req,
dst += bsize;
} while ((nbytes -= bsize) >= bsize);
- memcpy(walk->iv, iv, bsize);
-
return nbytes;
}
@@ -144,7 +140,7 @@ static int crypto_pcbc_decrypt_inplace(struct skcipher_request *req,
int bsize = crypto_cipher_blocksize(tfm);
unsigned int nbytes = walk->nbytes;
u8 *src = walk->src.virt.addr;
- u8 *iv = walk->iv;
+ u8 * const iv = walk->iv;
u8 tmpbuf[MAX_CIPHER_BLOCKSIZE] __aligned(__alignof__(u32));
do {
@@ -156,8 +152,6 @@ static int crypto_pcbc_decrypt_inplace(struct skcipher_request *req,
src += bsize;
} while ((nbytes -= bsize) >= bsize);
- memcpy(walk->iv, iv, bsize);
-
return nbytes;
}