--- /dev/null
+From ec98ea7070e94cc25a422ec97d1421e28d97b7ee Mon Sep 17 00:00:00 2001
+From: Chris Leech <cleech@redhat.com>
+Date: Tue, 23 Feb 2021 18:00:17 -0800
+Subject: scsi: iscsi: Ensure sysfs attributes are limited to PAGE_SIZE
+
+From: Chris Leech <cleech@redhat.com>
+
+commit ec98ea7070e94cc25a422ec97d1421e28d97b7ee upstream.
+
+As the iSCSI parameters are exported back through sysfs, it should be
+enforcing that they never are more than PAGE_SIZE (which should be more
+than enough) before accepting updates through netlink.
+
+Change all iSCSI sysfs attributes to use sysfs_emit().
+
+Cc: stable@vger.kernel.org
+Reported-by: Adam Nichols <adam@grimm-co.com>
+Reviewed-by: Lee Duncan <lduncan@suse.com>
+Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Reviewed-by: Mike Christie <michael.christie@oracle.com>
+Signed-off-by: Chris Leech <cleech@redhat.com>
+Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/scsi/libiscsi.c | 148 ++++++++++++++++++------------------
+ drivers/scsi/scsi_transport_iscsi.c | 23 +++--
+ 2 files changed, 89 insertions(+), 82 deletions(-)
+
+--- a/drivers/scsi/libiscsi.c
++++ b/drivers/scsi/libiscsi.c
+@@ -3331,125 +3331,125 @@ int iscsi_session_get_param(struct iscsi
+
+ switch(param) {
+ case ISCSI_PARAM_FAST_ABORT:
+- len = sprintf(buf, "%d\n", session->fast_abort);
++ len = sysfs_emit(buf, "%d\n", session->fast_abort);
+ break;
+ case ISCSI_PARAM_ABORT_TMO:
+- len = sprintf(buf, "%d\n", session->abort_timeout);
++ len = sysfs_emit(buf, "%d\n", session->abort_timeout);
+ break;
+ case ISCSI_PARAM_LU_RESET_TMO:
+- len = sprintf(buf, "%d\n", session->lu_reset_timeout);
++ len = sysfs_emit(buf, "%d\n", session->lu_reset_timeout);
+ break;
+ case ISCSI_PARAM_TGT_RESET_TMO:
+- len = sprintf(buf, "%d\n", session->tgt_reset_timeout);
++ len = sysfs_emit(buf, "%d\n", session->tgt_reset_timeout);
+ break;
+ case ISCSI_PARAM_INITIAL_R2T_EN:
+- len = sprintf(buf, "%d\n", session->initial_r2t_en);
++ len = sysfs_emit(buf, "%d\n", session->initial_r2t_en);
+ break;
+ case ISCSI_PARAM_MAX_R2T:
+- len = sprintf(buf, "%hu\n", session->max_r2t);
++ len = sysfs_emit(buf, "%hu\n", session->max_r2t);
+ break;
+ case ISCSI_PARAM_IMM_DATA_EN:
+- len = sprintf(buf, "%d\n", session->imm_data_en);
++ len = sysfs_emit(buf, "%d\n", session->imm_data_en);
+ break;
+ case ISCSI_PARAM_FIRST_BURST:
+- len = sprintf(buf, "%u\n", session->first_burst);
++ len = sysfs_emit(buf, "%u\n", session->first_burst);
+ break;
+ case ISCSI_PARAM_MAX_BURST:
+- len = sprintf(buf, "%u\n", session->max_burst);
++ len = sysfs_emit(buf, "%u\n", session->max_burst);
+ break;
+ case ISCSI_PARAM_PDU_INORDER_EN:
+- len = sprintf(buf, "%d\n", session->pdu_inorder_en);
++ len = sysfs_emit(buf, "%d\n", session->pdu_inorder_en);
+ break;
+ case ISCSI_PARAM_DATASEQ_INORDER_EN:
+- len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
++ len = sysfs_emit(buf, "%d\n", session->dataseq_inorder_en);
+ break;
+ case ISCSI_PARAM_DEF_TASKMGMT_TMO:
+- len = sprintf(buf, "%d\n", session->def_taskmgmt_tmo);
++ len = sysfs_emit(buf, "%d\n", session->def_taskmgmt_tmo);
+ break;
+ case ISCSI_PARAM_ERL:
+- len = sprintf(buf, "%d\n", session->erl);
++ len = sysfs_emit(buf, "%d\n", session->erl);
+ break;
+ case ISCSI_PARAM_TARGET_NAME:
+- len = sprintf(buf, "%s\n", session->targetname);
++ len = sysfs_emit(buf, "%s\n", session->targetname);
+ break;
+ case ISCSI_PARAM_TARGET_ALIAS:
+- len = sprintf(buf, "%s\n", session->targetalias);
++ len = sysfs_emit(buf, "%s\n", session->targetalias);
+ break;
+ case ISCSI_PARAM_TPGT:
+- len = sprintf(buf, "%d\n", session->tpgt);
++ len = sysfs_emit(buf, "%d\n", session->tpgt);
+ break;
+ case ISCSI_PARAM_USERNAME:
+- len = sprintf(buf, "%s\n", session->username);
++ len = sysfs_emit(buf, "%s\n", session->username);
+ break;
+ case ISCSI_PARAM_USERNAME_IN:
+- len = sprintf(buf, "%s\n", session->username_in);
++ len = sysfs_emit(buf, "%s\n", session->username_in);
+ break;
+ case ISCSI_PARAM_PASSWORD:
+- len = sprintf(buf, "%s\n", session->password);
++ len = sysfs_emit(buf, "%s\n", session->password);
+ break;
+ case ISCSI_PARAM_PASSWORD_IN:
+- len = sprintf(buf, "%s\n", session->password_in);
++ len = sysfs_emit(buf, "%s\n", session->password_in);
+ break;
+ case ISCSI_PARAM_IFACE_NAME:
+- len = sprintf(buf, "%s\n", session->ifacename);
++ len = sysfs_emit(buf, "%s\n", session->ifacename);
+ break;
+ case ISCSI_PARAM_INITIATOR_NAME:
+- len = sprintf(buf, "%s\n", session->initiatorname);
++ len = sysfs_emit(buf, "%s\n", session->initiatorname);
+ break;
+ case ISCSI_PARAM_BOOT_ROOT:
+- len = sprintf(buf, "%s\n", session->boot_root);
++ len = sysfs_emit(buf, "%s\n", session->boot_root);
+ break;
+ case ISCSI_PARAM_BOOT_NIC:
+- len = sprintf(buf, "%s\n", session->boot_nic);
++ len = sysfs_emit(buf, "%s\n", session->boot_nic);
+ break;
+ case ISCSI_PARAM_BOOT_TARGET:
+- len = sprintf(buf, "%s\n", session->boot_target);
++ len = sysfs_emit(buf, "%s\n", session->boot_target);
+ break;
+ case ISCSI_PARAM_AUTO_SND_TGT_DISABLE:
+- len = sprintf(buf, "%u\n", session->auto_snd_tgt_disable);
++ len = sysfs_emit(buf, "%u\n", session->auto_snd_tgt_disable);
+ break;
+ case ISCSI_PARAM_DISCOVERY_SESS:
+- len = sprintf(buf, "%u\n", session->discovery_sess);
++ len = sysfs_emit(buf, "%u\n", session->discovery_sess);
+ break;
+ case ISCSI_PARAM_PORTAL_TYPE:
+- len = sprintf(buf, "%s\n", session->portal_type);
++ len = sysfs_emit(buf, "%s\n", session->portal_type);
+ break;
+ case ISCSI_PARAM_CHAP_AUTH_EN:
+- len = sprintf(buf, "%u\n", session->chap_auth_en);
++ len = sysfs_emit(buf, "%u\n", session->chap_auth_en);
+ break;
+ case ISCSI_PARAM_DISCOVERY_LOGOUT_EN:
+- len = sprintf(buf, "%u\n", session->discovery_logout_en);
++ len = sysfs_emit(buf, "%u\n", session->discovery_logout_en);
+ break;
+ case ISCSI_PARAM_BIDI_CHAP_EN:
+- len = sprintf(buf, "%u\n", session->bidi_chap_en);
++ len = sysfs_emit(buf, "%u\n", session->bidi_chap_en);
+ break;
+ case ISCSI_PARAM_DISCOVERY_AUTH_OPTIONAL:
+- len = sprintf(buf, "%u\n", session->discovery_auth_optional);
++ len = sysfs_emit(buf, "%u\n", session->discovery_auth_optional);
+ break;
+ case ISCSI_PARAM_DEF_TIME2WAIT:
+- len = sprintf(buf, "%d\n", session->time2wait);
++ len = sysfs_emit(buf, "%d\n", session->time2wait);
+ break;
+ case ISCSI_PARAM_DEF_TIME2RETAIN:
+- len = sprintf(buf, "%d\n", session->time2retain);
++ len = sysfs_emit(buf, "%d\n", session->time2retain);
+ break;
+ case ISCSI_PARAM_TSID:
+- len = sprintf(buf, "%u\n", session->tsid);
++ len = sysfs_emit(buf, "%u\n", session->tsid);
+ break;
+ case ISCSI_PARAM_ISID:
+- len = sprintf(buf, "%02x%02x%02x%02x%02x%02x\n",
++ len = sysfs_emit(buf, "%02x%02x%02x%02x%02x%02x\n",
+ session->isid[0], session->isid[1],
+ session->isid[2], session->isid[3],
+ session->isid[4], session->isid[5]);
+ break;
+ case ISCSI_PARAM_DISCOVERY_PARENT_IDX:
+- len = sprintf(buf, "%u\n", session->discovery_parent_idx);
++ len = sysfs_emit(buf, "%u\n", session->discovery_parent_idx);
+ break;
+ case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
+ if (session->discovery_parent_type)
+- len = sprintf(buf, "%s\n",
++ len = sysfs_emit(buf, "%s\n",
+ session->discovery_parent_type);
+ else
+- len = sprintf(buf, "\n");
++ len = sysfs_emit(buf, "\n");
+ break;
+ default:
+ return -ENOSYS;
+@@ -3481,16 +3481,16 @@ int iscsi_conn_get_addr_param(struct soc
+ case ISCSI_PARAM_CONN_ADDRESS:
+ case ISCSI_HOST_PARAM_IPADDRESS:
+ if (sin)
+- len = sprintf(buf, "%pI4\n", &sin->sin_addr.s_addr);
++ len = sysfs_emit(buf, "%pI4\n", &sin->sin_addr.s_addr);
+ else
+- len = sprintf(buf, "%pI6\n", &sin6->sin6_addr);
++ len = sysfs_emit(buf, "%pI6\n", &sin6->sin6_addr);
+ break;
+ case ISCSI_PARAM_CONN_PORT:
+ case ISCSI_PARAM_LOCAL_PORT:
+ if (sin)
+- len = sprintf(buf, "%hu\n", be16_to_cpu(sin->sin_port));
++ len = sysfs_emit(buf, "%hu\n", be16_to_cpu(sin->sin_port));
+ else
+- len = sprintf(buf, "%hu\n",
++ len = sysfs_emit(buf, "%hu\n",
+ be16_to_cpu(sin6->sin6_port));
+ break;
+ default:
+@@ -3509,88 +3509,88 @@ int iscsi_conn_get_param(struct iscsi_cl
+
+ switch(param) {
+ case ISCSI_PARAM_PING_TMO:
+- len = sprintf(buf, "%u\n", conn->ping_timeout);
++ len = sysfs_emit(buf, "%u\n", conn->ping_timeout);
+ break;
+ case ISCSI_PARAM_RECV_TMO:
+- len = sprintf(buf, "%u\n", conn->recv_timeout);
++ len = sysfs_emit(buf, "%u\n", conn->recv_timeout);
+ break;
+ case ISCSI_PARAM_MAX_RECV_DLENGTH:
+- len = sprintf(buf, "%u\n", conn->max_recv_dlength);
++ len = sysfs_emit(buf, "%u\n", conn->max_recv_dlength);
+ break;
+ case ISCSI_PARAM_MAX_XMIT_DLENGTH:
+- len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
++ len = sysfs_emit(buf, "%u\n", conn->max_xmit_dlength);
+ break;
+ case ISCSI_PARAM_HDRDGST_EN:
+- len = sprintf(buf, "%d\n", conn->hdrdgst_en);
++ len = sysfs_emit(buf, "%d\n", conn->hdrdgst_en);
+ break;
+ case ISCSI_PARAM_DATADGST_EN:
+- len = sprintf(buf, "%d\n", conn->datadgst_en);
++ len = sysfs_emit(buf, "%d\n", conn->datadgst_en);
+ break;
+ case ISCSI_PARAM_IFMARKER_EN:
+- len = sprintf(buf, "%d\n", conn->ifmarker_en);
++ len = sysfs_emit(buf, "%d\n", conn->ifmarker_en);
+ break;
+ case ISCSI_PARAM_OFMARKER_EN:
+- len = sprintf(buf, "%d\n", conn->ofmarker_en);
++ len = sysfs_emit(buf, "%d\n", conn->ofmarker_en);
+ break;
+ case ISCSI_PARAM_EXP_STATSN:
+- len = sprintf(buf, "%u\n", conn->exp_statsn);
++ len = sysfs_emit(buf, "%u\n", conn->exp_statsn);
+ break;
+ case ISCSI_PARAM_PERSISTENT_PORT:
+- len = sprintf(buf, "%d\n", conn->persistent_port);
++ len = sysfs_emit(buf, "%d\n", conn->persistent_port);
+ break;
+ case ISCSI_PARAM_PERSISTENT_ADDRESS:
+- len = sprintf(buf, "%s\n", conn->persistent_address);
++ len = sysfs_emit(buf, "%s\n", conn->persistent_address);
+ break;
+ case ISCSI_PARAM_STATSN:
+- len = sprintf(buf, "%u\n", conn->statsn);
++ len = sysfs_emit(buf, "%u\n", conn->statsn);
+ break;
+ case ISCSI_PARAM_MAX_SEGMENT_SIZE:
+- len = sprintf(buf, "%u\n", conn->max_segment_size);
++ len = sysfs_emit(buf, "%u\n", conn->max_segment_size);
+ break;
+ case ISCSI_PARAM_KEEPALIVE_TMO:
+- len = sprintf(buf, "%u\n", conn->keepalive_tmo);
++ len = sysfs_emit(buf, "%u\n", conn->keepalive_tmo);
+ break;
+ case ISCSI_PARAM_LOCAL_PORT:
+- len = sprintf(buf, "%u\n", conn->local_port);
++ len = sysfs_emit(buf, "%u\n", conn->local_port);
+ break;
+ case ISCSI_PARAM_TCP_TIMESTAMP_STAT:
+- len = sprintf(buf, "%u\n", conn->tcp_timestamp_stat);
++ len = sysfs_emit(buf, "%u\n", conn->tcp_timestamp_stat);
+ break;
+ case ISCSI_PARAM_TCP_NAGLE_DISABLE:
+- len = sprintf(buf, "%u\n", conn->tcp_nagle_disable);
++ len = sysfs_emit(buf, "%u\n", conn->tcp_nagle_disable);
+ break;
+ case ISCSI_PARAM_TCP_WSF_DISABLE:
+- len = sprintf(buf, "%u\n", conn->tcp_wsf_disable);
++ len = sysfs_emit(buf, "%u\n", conn->tcp_wsf_disable);
+ break;
+ case ISCSI_PARAM_TCP_TIMER_SCALE:
+- len = sprintf(buf, "%u\n", conn->tcp_timer_scale);
++ len = sysfs_emit(buf, "%u\n", conn->tcp_timer_scale);
+ break;
+ case ISCSI_PARAM_TCP_TIMESTAMP_EN:
+- len = sprintf(buf, "%u\n", conn->tcp_timestamp_en);
++ len = sysfs_emit(buf, "%u\n", conn->tcp_timestamp_en);
+ break;
+ case ISCSI_PARAM_IP_FRAGMENT_DISABLE:
+- len = sprintf(buf, "%u\n", conn->fragment_disable);
++ len = sysfs_emit(buf, "%u\n", conn->fragment_disable);
+ break;
+ case ISCSI_PARAM_IPV4_TOS:
+- len = sprintf(buf, "%u\n", conn->ipv4_tos);
++ len = sysfs_emit(buf, "%u\n", conn->ipv4_tos);
+ break;
+ case ISCSI_PARAM_IPV6_TC:
+- len = sprintf(buf, "%u\n", conn->ipv6_traffic_class);
++ len = sysfs_emit(buf, "%u\n", conn->ipv6_traffic_class);
+ break;
+ case ISCSI_PARAM_IPV6_FLOW_LABEL:
+- len = sprintf(buf, "%u\n", conn->ipv6_flow_label);
++ len = sysfs_emit(buf, "%u\n", conn->ipv6_flow_label);
+ break;
+ case ISCSI_PARAM_IS_FW_ASSIGNED_IPV6:
+- len = sprintf(buf, "%u\n", conn->is_fw_assigned_ipv6);
++ len = sysfs_emit(buf, "%u\n", conn->is_fw_assigned_ipv6);
+ break;
+ case ISCSI_PARAM_TCP_XMIT_WSF:
+- len = sprintf(buf, "%u\n", conn->tcp_xmit_wsf);
++ len = sysfs_emit(buf, "%u\n", conn->tcp_xmit_wsf);
+ break;
+ case ISCSI_PARAM_TCP_RECV_WSF:
+- len = sprintf(buf, "%u\n", conn->tcp_recv_wsf);
++ len = sysfs_emit(buf, "%u\n", conn->tcp_recv_wsf);
+ break;
+ case ISCSI_PARAM_LOCAL_IPADDR:
+- len = sprintf(buf, "%s\n", conn->local_ipaddr);
++ len = sysfs_emit(buf, "%s\n", conn->local_ipaddr);
+ break;
+ default:
+ return -ENOSYS;
+@@ -3608,13 +3608,13 @@ int iscsi_host_get_param(struct Scsi_Hos
+
+ switch (param) {
+ case ISCSI_HOST_PARAM_NETDEV_NAME:
+- len = sprintf(buf, "%s\n", ihost->netdev);
++ len = sysfs_emit(buf, "%s\n", ihost->netdev);
+ break;
+ case ISCSI_HOST_PARAM_HWADDRESS:
+- len = sprintf(buf, "%s\n", ihost->hwaddress);
++ len = sysfs_emit(buf, "%s\n", ihost->hwaddress);
+ break;
+ case ISCSI_HOST_PARAM_INITIATOR_NAME:
+- len = sprintf(buf, "%s\n", ihost->initiatorname);
++ len = sysfs_emit(buf, "%s\n", ihost->initiatorname);
+ break;
+ default:
+ return -ENOSYS;
+--- a/drivers/scsi/scsi_transport_iscsi.c
++++ b/drivers/scsi/scsi_transport_iscsi.c
+@@ -127,7 +127,8 @@ show_transport_handle(struct device *dev
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+- return sprintf(buf, "%llu\n", (unsigned long long)iscsi_handle(priv->iscsi_transport));
++ return sysfs_emit(buf, "%llu\n",
++ (unsigned long long)iscsi_handle(priv->iscsi_transport));
+ }
+ static DEVICE_ATTR(handle, S_IRUGO, show_transport_handle, NULL);
+
+@@ -137,7 +138,7 @@ show_transport_##name(struct device *dev
+ struct device_attribute *attr,char *buf) \
+ { \
+ struct iscsi_internal *priv = dev_to_iscsi_internal(dev); \
+- return sprintf(buf, format"\n", priv->iscsi_transport->name); \
++ return sysfs_emit(buf, format"\n", priv->iscsi_transport->name);\
+ } \
+ static DEVICE_ATTR(name, S_IRUGO, show_transport_##name, NULL);
+
+@@ -178,7 +179,7 @@ static ssize_t
+ show_ep_handle(struct device *dev, struct device_attribute *attr, char *buf)
+ {
+ struct iscsi_endpoint *ep = iscsi_dev_to_endpoint(dev);
+- return sprintf(buf, "%llu\n", (unsigned long long) ep->id);
++ return sysfs_emit(buf, "%llu\n", (unsigned long long) ep->id);
+ }
+ static ISCSI_ATTR(ep, handle, S_IRUGO, show_ep_handle, NULL);
+
+@@ -2768,6 +2769,9 @@ iscsi_set_param(struct iscsi_transport *
+ struct iscsi_cls_session *session;
+ int err = 0, value = 0;
+
++ if (ev->u.set_param.len > PAGE_SIZE)
++ return -EINVAL;
++
+ session = iscsi_session_lookup(ev->u.set_param.sid);
+ conn = iscsi_conn_lookup(ev->u.set_param.sid, ev->u.set_param.cid);
+ if (!conn || !session)
+@@ -2915,6 +2919,9 @@ iscsi_set_host_param(struct iscsi_transp
+ if (!transport->set_host_param)
+ return -ENOSYS;
+
++ if (ev->u.set_host_param.len > PAGE_SIZE)
++ return -EINVAL;
++
+ shost = scsi_host_lookup(ev->u.set_host_param.host_no);
+ if (!shost) {
+ printk(KERN_ERR "set_host_param could not find host no %u\n",
+@@ -4025,7 +4032,7 @@ show_priv_session_state(struct device *d
+ char *buf)
+ {
+ struct iscsi_cls_session *session = iscsi_dev_to_session(dev->parent);
+- return sprintf(buf, "%s\n", iscsi_session_state_name(session->state));
++ return sysfs_emit(buf, "%s\n", iscsi_session_state_name(session->state));
+ }
+ static ISCSI_CLASS_ATTR(priv_sess, state, S_IRUGO, show_priv_session_state,
+ NULL);
+@@ -4034,7 +4041,7 @@ show_priv_session_creator(struct device
+ char *buf)
+ {
+ struct iscsi_cls_session *session = iscsi_dev_to_session(dev->parent);
+- return sprintf(buf, "%d\n", session->creator);
++ return sysfs_emit(buf, "%d\n", session->creator);
+ }
+ static ISCSI_CLASS_ATTR(priv_sess, creator, S_IRUGO, show_priv_session_creator,
+ NULL);
+@@ -4043,7 +4050,7 @@ show_priv_session_target_id(struct devic
+ char *buf)
+ {
+ struct iscsi_cls_session *session = iscsi_dev_to_session(dev->parent);
+- return sprintf(buf, "%d\n", session->target_id);
++ return sysfs_emit(buf, "%d\n", session->target_id);
+ }
+ static ISCSI_CLASS_ATTR(priv_sess, target_id, S_IRUGO,
+ show_priv_session_target_id, NULL);
+@@ -4056,8 +4063,8 @@ show_priv_session_##field(struct device
+ struct iscsi_cls_session *session = \
+ iscsi_dev_to_session(dev->parent); \
+ if (session->field == -1) \
+- return sprintf(buf, "off\n"); \
+- return sprintf(buf, format"\n", session->field); \
++ return sysfs_emit(buf, "off\n"); \
++ return sysfs_emit(buf, format"\n", session->field); \
+ }
+
+ #define iscsi_priv_session_attr_store(field) \
--- /dev/null
+From 2efc459d06f1630001e3984854848a5647086232 Mon Sep 17 00:00:00 2001
+From: Joe Perches <joe@perches.com>
+Date: Wed, 16 Sep 2020 13:40:38 -0700
+Subject: sysfs: Add sysfs_emit and sysfs_emit_at to format sysfs output
+
+From: Joe Perches <joe@perches.com>
+
+commit 2efc459d06f1630001e3984854848a5647086232 upstream.
+
+Output defects can exist in sysfs content using sprintf and snprintf.
+
+sprintf does not know the PAGE_SIZE maximum of the temporary buffer
+used for outputting sysfs content and it's possible to overrun the
+PAGE_SIZE buffer length.
+
+Add a generic sysfs_emit function that knows that the size of the
+temporary buffer and ensures that no overrun is done.
+
+Add a generic sysfs_emit_at function that can be used in multiple
+call situations that also ensures that no overrun is done.
+
+Validate the output buffer argument to be page aligned.
+Validate the offset len argument to be within the PAGE_SIZE buf.
+
+Signed-off-by: Joe Perches <joe@perches.com>
+Link: https://lore.kernel.org/r/884235202216d464d61ee975f7465332c86f76b2.1600285923.git.joe@perches.com
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ Documentation/filesystems/sysfs.txt | 8 +----
+ fs/sysfs/file.c | 55 ++++++++++++++++++++++++++++++++++++
+ include/linux/sysfs.h | 16 ++++++++++
+ 3 files changed, 74 insertions(+), 5 deletions(-)
+
+--- a/Documentation/filesystems/sysfs.txt
++++ b/Documentation/filesystems/sysfs.txt
+@@ -232,12 +232,10 @@ Other notes:
+ is 4096.
+
+ - show() methods should return the number of bytes printed into the
+- buffer. This is the return value of scnprintf().
++ buffer.
+
+-- show() must not use snprintf() when formatting the value to be
+- returned to user space. If you can guarantee that an overflow
+- will never happen you can use sprintf() otherwise you must use
+- scnprintf().
++- show() should only use sysfs_emit() or sysfs_emit_at() when formatting
++ the value to be returned to user space.
+
+ - store() should return the number of bytes used from the buffer. If the
+ entire buffer has been used, just return the count argument.
+--- a/fs/sysfs/file.c
++++ b/fs/sysfs/file.c
+@@ -15,6 +15,7 @@
+ #include <linux/list.h>
+ #include <linux/mutex.h>
+ #include <linux/seq_file.h>
++#include <linux/mm.h>
+
+ #include "sysfs.h"
+
+@@ -558,3 +559,57 @@ void sysfs_remove_bin_file(struct kobjec
+ kernfs_remove_by_name(kobj->sd, attr->attr.name);
+ }
+ EXPORT_SYMBOL_GPL(sysfs_remove_bin_file);
++
++/**
++ * sysfs_emit - scnprintf equivalent, aware of PAGE_SIZE buffer.
++ * @buf: start of PAGE_SIZE buffer.
++ * @fmt: format
++ * @...: optional arguments to @format
++ *
++ *
++ * Returns number of characters written to @buf.
++ */
++int sysfs_emit(char *buf, const char *fmt, ...)
++{
++ va_list args;
++ int len;
++
++ if (WARN(!buf || offset_in_page(buf),
++ "invalid sysfs_emit: buf:%p\n", buf))
++ return 0;
++
++ va_start(args, fmt);
++ len = vscnprintf(buf, PAGE_SIZE, fmt, args);
++ va_end(args);
++
++ return len;
++}
++EXPORT_SYMBOL_GPL(sysfs_emit);
++
++/**
++ * sysfs_emit_at - scnprintf equivalent, aware of PAGE_SIZE buffer.
++ * @buf: start of PAGE_SIZE buffer.
++ * @at: offset in @buf to start write in bytes
++ * @at must be >= 0 && < PAGE_SIZE
++ * @fmt: format
++ * @...: optional arguments to @fmt
++ *
++ *
++ * Returns number of characters written starting at &@buf[@at].
++ */
++int sysfs_emit_at(char *buf, int at, const char *fmt, ...)
++{
++ va_list args;
++ int len;
++
++ if (WARN(!buf || offset_in_page(buf) || at < 0 || at >= PAGE_SIZE,
++ "invalid sysfs_emit_at: buf:%p at:%d\n", buf, at))
++ return 0;
++
++ va_start(args, fmt);
++ len = vscnprintf(buf + at, PAGE_SIZE - at, fmt, args);
++ va_end(args);
++
++ return len;
++}
++EXPORT_SYMBOL_GPL(sysfs_emit_at);
+--- a/include/linux/sysfs.h
++++ b/include/linux/sysfs.h
+@@ -310,6 +310,11 @@ static inline void sysfs_enable_ns(struc
+ return kernfs_enable_ns(kn);
+ }
+
++__printf(2, 3)
++int sysfs_emit(char *buf, const char *fmt, ...);
++__printf(3, 4)
++int sysfs_emit_at(char *buf, int at, const char *fmt, ...);
++
+ #else /* CONFIG_SYSFS */
+
+ static inline int sysfs_create_dir_ns(struct kobject *kobj, const void *ns)
+@@ -522,6 +527,17 @@ static inline void sysfs_enable_ns(struc
+ {
+ }
+
++__printf(2, 3)
++static inline int sysfs_emit(char *buf, const char *fmt, ...)
++{
++ return 0;
++}
++
++__printf(3, 4)
++static inline int sysfs_emit_at(char *buf, int at, const char *fmt, ...)
++{
++ return 0;
++}
+ #endif /* CONFIG_SYSFS */
+
+ static inline int __must_check sysfs_create_file(struct kobject *kobj,
--- /dev/null
+From 8310b77b48c5558c140e7a57a702e7819e62f04e Mon Sep 17 00:00:00 2001
+From: Jan Beulich <jbeulich@suse.com>
+Date: Thu, 25 Feb 2021 16:34:43 +0100
+Subject: Xen/gnttab: handle p2m update errors on a per-slot basis
+
+From: Jan Beulich <jbeulich@suse.com>
+
+commit 8310b77b48c5558c140e7a57a702e7819e62f04e upstream.
+
+Bailing immediately from set_foreign_p2m_mapping() upon a p2m updating
+error leaves the full batch in an ambiguous state as far as the caller
+is concerned. Instead flags respective slots as bad, unmapping what
+was mapped there right away.
+
+HYPERVISOR_grant_table_op()'s return value and the individual unmap
+slots' status fields get used only for a one-time - there's not much we
+can do in case of a failure.
+
+Note that there's no GNTST_enomem or alike, so GNTST_general_error gets
+used.
+
+The map ops' handle fields get overwritten just to be on the safe side.
+
+This is part of XSA-367.
+
+Cc: <stable@vger.kernel.org>
+Signed-off-by: Jan Beulich <jbeulich@suse.com>
+Reviewed-by: Juergen Gross <jgross@suse.com>
+Link: https://lore.kernel.org/r/96cccf5d-e756-5f53-b91a-ea269bfb9be0@suse.com
+Signed-off-by: Juergen Gross <jgross@suse.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/arm/xen/p2m.c | 35 +++++++++++++++++++++++++++++++----
+ arch/x86/xen/p2m.c | 44 +++++++++++++++++++++++++++++++++++++++++---
+ 2 files changed, 72 insertions(+), 7 deletions(-)
+
+--- a/arch/arm/xen/p2m.c
++++ b/arch/arm/xen/p2m.c
+@@ -93,12 +93,39 @@ int set_foreign_p2m_mapping(struct gntta
+ int i;
+
+ for (i = 0; i < count; i++) {
++ struct gnttab_unmap_grant_ref unmap;
++ int rc;
++
+ if (map_ops[i].status)
+ continue;
+- if (unlikely(!set_phys_to_machine(map_ops[i].host_addr >> XEN_PAGE_SHIFT,
+- map_ops[i].dev_bus_addr >> XEN_PAGE_SHIFT))) {
+- return -ENOMEM;
+- }
++ if (likely(set_phys_to_machine(map_ops[i].host_addr >> XEN_PAGE_SHIFT,
++ map_ops[i].dev_bus_addr >> XEN_PAGE_SHIFT)))
++ continue;
++
++ /*
++ * Signal an error for this slot. This in turn requires
++ * immediate unmapping.
++ */
++ map_ops[i].status = GNTST_general_error;
++ unmap.host_addr = map_ops[i].host_addr,
++ unmap.handle = map_ops[i].handle;
++ map_ops[i].handle = ~0;
++ if (map_ops[i].flags & GNTMAP_device_map)
++ unmap.dev_bus_addr = map_ops[i].dev_bus_addr;
++ else
++ unmap.dev_bus_addr = 0;
++
++ /*
++ * Pre-populate the status field, to be recognizable in
++ * the log message below.
++ */
++ unmap.status = 1;
++
++ rc = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref,
++ &unmap, 1);
++ if (rc || unmap.status != GNTST_okay)
++ pr_err_once("gnttab unmap failed: rc=%d st=%d\n",
++ rc, unmap.status);
+ }
+
+ return 0;
+--- a/arch/x86/xen/p2m.c
++++ b/arch/x86/xen/p2m.c
+@@ -714,6 +714,8 @@ int set_foreign_p2m_mapping(struct gntta
+
+ for (i = 0; i < count; i++) {
+ unsigned long mfn, pfn;
++ struct gnttab_unmap_grant_ref unmap[2];
++ int rc;
+
+ /* Do not add to override if the map failed. */
+ if (map_ops[i].status != GNTST_okay ||
+@@ -731,10 +733,46 @@ int set_foreign_p2m_mapping(struct gntta
+
+ WARN(pfn_to_mfn(pfn) != INVALID_P2M_ENTRY, "page must be ballooned");
+
+- if (unlikely(!set_phys_to_machine(pfn, FOREIGN_FRAME(mfn)))) {
+- ret = -ENOMEM;
+- goto out;
++ if (likely(set_phys_to_machine(pfn, FOREIGN_FRAME(mfn))))
++ continue;
++
++ /*
++ * Signal an error for this slot. This in turn requires
++ * immediate unmapping.
++ */
++ map_ops[i].status = GNTST_general_error;
++ unmap[0].host_addr = map_ops[i].host_addr,
++ unmap[0].handle = map_ops[i].handle;
++ map_ops[i].handle = ~0;
++ if (map_ops[i].flags & GNTMAP_device_map)
++ unmap[0].dev_bus_addr = map_ops[i].dev_bus_addr;
++ else
++ unmap[0].dev_bus_addr = 0;
++
++ if (kmap_ops) {
++ kmap_ops[i].status = GNTST_general_error;
++ unmap[1].host_addr = kmap_ops[i].host_addr,
++ unmap[1].handle = kmap_ops[i].handle;
++ kmap_ops[i].handle = ~0;
++ if (kmap_ops[i].flags & GNTMAP_device_map)
++ unmap[1].dev_bus_addr = kmap_ops[i].dev_bus_addr;
++ else
++ unmap[1].dev_bus_addr = 0;
+ }
++
++ /*
++ * Pre-populate both status fields, to be recognizable in
++ * the log message below.
++ */
++ unmap[0].status = 1;
++ unmap[1].status = 1;
++
++ rc = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref,
++ unmap, 1 + !!kmap_ops);
++ if (rc || unmap[0].status != GNTST_okay ||
++ unmap[1].status != GNTST_okay)
++ pr_err_once("gnttab unmap failed: rc=%d st0=%d st1=%d\n",
++ rc, unmap[0].status, unmap[1].status);
+ }
+
+ out:
--- /dev/null
+From 2395928158059b8f9858365fce7713ce7fef62e4 Mon Sep 17 00:00:00 2001
+From: Rokudo Yan <wu-yan@tcl.com>
+Date: Thu, 25 Feb 2021 17:18:31 -0800
+Subject: zsmalloc: account the number of compacted pages correctly
+
+From: Rokudo Yan <wu-yan@tcl.com>
+
+commit 2395928158059b8f9858365fce7713ce7fef62e4 upstream.
+
+There exists multiple path may do zram compaction concurrently.
+1. auto-compaction triggered during memory reclaim
+2. userspace utils write zram<id>/compaction node
+
+So, multiple threads may call zs_shrinker_scan/zs_compact concurrently.
+But pages_compacted is a per zsmalloc pool variable and modification
+of the variable is not serialized(through under class->lock).
+There are two issues here:
+1. the pages_compacted may not equal to total number of pages
+freed(due to concurrently add).
+2. zs_shrinker_scan may not return the correct number of pages
+freed(issued by current shrinker).
+
+The fix is simple:
+1. account the number of pages freed in zs_compact locally.
+2. use actomic variable pages_compacted to accumulate total number.
+
+Link: https://lkml.kernel.org/r/20210202122235.26885-1-wu-yan@tcl.com
+Fixes: 860c707dca155a56 ("zsmalloc: account the number of compacted pages")
+Signed-off-by: Rokudo Yan <wu-yan@tcl.com>
+Cc: Minchan Kim <minchan@kernel.org>
+Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
+Cc: <stable@vger.kernel.org>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/block/zram/zram_drv.c | 2 +-
+ include/linux/zsmalloc.h | 2 +-
+ mm/zsmalloc.c | 17 +++++++++++------
+ 3 files changed, 13 insertions(+), 8 deletions(-)
+
+--- a/drivers/block/zram/zram_drv.c
++++ b/drivers/block/zram/zram_drv.c
+@@ -1072,7 +1072,7 @@ static ssize_t mm_stat_show(struct devic
+ zram->limit_pages << PAGE_SHIFT,
+ max_used << PAGE_SHIFT,
+ (u64)atomic64_read(&zram->stats.same_pages),
+- pool_stats.pages_compacted,
++ atomic_long_read(&pool_stats.pages_compacted),
+ (u64)atomic64_read(&zram->stats.huge_pages));
+ up_read(&zram->init_lock);
+
+--- a/include/linux/zsmalloc.h
++++ b/include/linux/zsmalloc.h
+@@ -35,7 +35,7 @@ enum zs_mapmode {
+
+ struct zs_pool_stats {
+ /* How many pages were migrated (freed) */
+- unsigned long pages_compacted;
++ atomic_long_t pages_compacted;
+ };
+
+ struct zs_pool;
+--- a/mm/zsmalloc.c
++++ b/mm/zsmalloc.c
+@@ -2216,11 +2216,13 @@ static unsigned long zs_can_compact(stru
+ return obj_wasted * class->pages_per_zspage;
+ }
+
+-static void __zs_compact(struct zs_pool *pool, struct size_class *class)
++static unsigned long __zs_compact(struct zs_pool *pool,
++ struct size_class *class)
+ {
+ struct zs_compact_control cc;
+ struct zspage *src_zspage;
+ struct zspage *dst_zspage = NULL;
++ unsigned long pages_freed = 0;
+
+ spin_lock(&class->lock);
+ while ((src_zspage = isolate_zspage(class, true))) {
+@@ -2250,7 +2252,7 @@ static void __zs_compact(struct zs_pool
+ putback_zspage(class, dst_zspage);
+ if (putback_zspage(class, src_zspage) == ZS_EMPTY) {
+ free_zspage(pool, class, src_zspage);
+- pool->stats.pages_compacted += class->pages_per_zspage;
++ pages_freed += class->pages_per_zspage;
+ }
+ spin_unlock(&class->lock);
+ cond_resched();
+@@ -2261,12 +2263,15 @@ static void __zs_compact(struct zs_pool
+ putback_zspage(class, src_zspage);
+
+ spin_unlock(&class->lock);
++
++ return pages_freed;
+ }
+
+ unsigned long zs_compact(struct zs_pool *pool)
+ {
+ int i;
+ struct size_class *class;
++ unsigned long pages_freed = 0;
+
+ for (i = ZS_SIZE_CLASSES - 1; i >= 0; i--) {
+ class = pool->size_class[i];
+@@ -2274,10 +2279,11 @@ unsigned long zs_compact(struct zs_pool
+ continue;
+ if (class->index != i)
+ continue;
+- __zs_compact(pool, class);
++ pages_freed += __zs_compact(pool, class);
+ }
++ atomic_long_add(pages_freed, &pool->stats.pages_compacted);
+
+- return pool->stats.pages_compacted;
++ return pages_freed;
+ }
+ EXPORT_SYMBOL_GPL(zs_compact);
+
+@@ -2294,13 +2300,12 @@ static unsigned long zs_shrinker_scan(st
+ struct zs_pool *pool = container_of(shrinker, struct zs_pool,
+ shrinker);
+
+- pages_freed = pool->stats.pages_compacted;
+ /*
+ * Compact classes and calculate compaction delta.
+ * Can run concurrently with a manually triggered
+ * (by user) compaction.
+ */
+- pages_freed = zs_compact(pool) - pages_freed;
++ pages_freed = zs_compact(pool);
+
+ return pages_freed ? pages_freed : SHRINK_STOP;
+ }
projects / thirdparty / kernel / stable-queue.git / commitdiff
