Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Ingo Molnar:
 "Misc fixes:

   - three fixes and a cleanup for the resctrl code

   - a HyperV fix

   - a fix to /proc/kcore contents in live debugging sessions

   - a fix for the x86 decoder opcode map"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/decoder: Add TEST opcode to Group3-2
  x86/resctrl: Clean up unused function parameter in mkdir path
  x86/resctrl: Fix a deadlock due to inaccurate reference
  x86/resctrl: Fix use-after-free due to inaccurate refcount of rdtgroup
  x86/resctrl: Fix use-after-free when deleting resource groups
  x86/hyper-v: Add "polling" bit to hv_synic_sint
  x86/crash: Define arch_crash_save_vmcoreinfo() if CONFIG_CRASH_CORE=y

1 files changed, 25 insertions, 23 deletions

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 1504bcabc63c..8ca5e510f3ce 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -2060,7 +2060,7 @@ static int rdt_get_tree(struct fs_context *fc)
 
 	if (rdt_mon_capable) {
 		ret = mongroup_create_dir(rdtgroup_default.kn,
-					  NULL, "mon_groups",
+					  &rdtgroup_default, "mon_groups",
 					  &kn_mongrp);
 		if (ret < 0)
 			goto out_info;
@@ -2295,7 +2295,11 @@ static void free_all_child_rdtgrp(struct rdtgroup *rdtgrp)
 	list_for_each_entry_safe(sentry, stmp, head, mon.crdtgrp_list) {
 		free_rmid(sentry->mon.rmid);
 		list_del(&sentry->mon.crdtgrp_list);
-		kfree(sentry);
+
+		if (atomic_read(&sentry->waitcount) != 0)
+			sentry->flags = RDT_DELETED;
+		else
+			kfree(sentry);
 	}
 }
 
@@ -2333,7 +2337,11 @@ static void rmdir_all_sub(void)
 
 		kernfs_remove(rdtgrp->kn);
 		list_del(&rdtgrp->rdtgroup_list);
-		kfree(rdtgrp);
+
+		if (atomic_read(&rdtgrp->waitcount) != 0)
+			rdtgrp->flags = RDT_DELETED;
+		else
+			kfree(rdtgrp);
 	}
 	/* Notify online CPUs to update per cpu storage and PQR_ASSOC MSR */
 	update_closid_rmid(cpu_online_mask, &rdtgroup_default);
@@ -2536,7 +2544,7 @@ static int mkdir_mondata_all(struct kernfs_node *parent_kn,
 	/*
 	 * Create the mon_data directory first.
 	 */
-	ret = mongroup_create_dir(parent_kn, NULL, "mon_data", &kn);
+	ret = mongroup_create_dir(parent_kn, prgrp, "mon_data", &kn);
 	if (ret)
 		return ret;
 
@@ -2726,7 +2734,6 @@ static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp)
 }
 
 static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
-			     struct kernfs_node *prgrp_kn,
 			     const char *name, umode_t mode,
 			     enum rdt_group_type rtype, struct rdtgroup **r)
 {
@@ -2735,7 +2742,7 @@ static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
 	uint files = 0;
 	int ret;
 
-	prdtgrp = rdtgroup_kn_lock_live(prgrp_kn);
+	prdtgrp = rdtgroup_kn_lock_live(parent_kn);
 	if (!prdtgrp) {
 		ret = -ENODEV;
 		goto out_unlock;
@@ -2808,7 +2815,7 @@ static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
 	kernfs_activate(kn);
 
 	/*
-	 * The caller unlocks the prgrp_kn upon success.
+	 * The caller unlocks the parent_kn upon success.
 	 */
 	return 0;
 
@@ -2819,7 +2826,7 @@ out_destroy:
 out_free_rgrp:
 	kfree(rdtgrp);
 out_unlock:
-	rdtgroup_kn_unlock(prgrp_kn);
+	rdtgroup_kn_unlock(parent_kn);
 	return ret;
 }
 
@@ -2836,15 +2843,12 @@ static void mkdir_rdt_prepare_clean(struct rdtgroup *rgrp)
  * to monitor a subset of tasks and cpus in its parent ctrl_mon group.
  */
 static int rdtgroup_mkdir_mon(struct kernfs_node *parent_kn,
-			      struct kernfs_node *prgrp_kn,
-			      const char *name,
-			      umode_t mode)
+			      const char *name, umode_t mode)
 {
 	struct rdtgroup *rdtgrp, *prgrp;
 	int ret;
 
-	ret = mkdir_rdt_prepare(parent_kn, prgrp_kn, name, mode, RDTMON_GROUP,
-				&rdtgrp);
+	ret = mkdir_rdt_prepare(parent_kn, name, mode, RDTMON_GROUP, &rdtgrp);
 	if (ret)
 		return ret;
 
@@ -2857,7 +2861,7 @@ static int rdtgroup_mkdir_mon(struct kernfs_node *parent_kn,
 	 */
 	list_add_tail(&rdtgrp->mon.crdtgrp_list, &prgrp->mon.crdtgrp_list);
 
-	rdtgroup_kn_unlock(prgrp_kn);
+	rdtgroup_kn_unlock(parent_kn);
 	return ret;
 }
 
@@ -2866,7 +2870,6 @@ static int rdtgroup_mkdir_mon(struct kernfs_node *parent_kn,
  * to allocate and monitor resources.
  */
 static int rdtgroup_mkdir_ctrl_mon(struct kernfs_node *parent_kn,
-				   struct kernfs_node *prgrp_kn,
 				   const char *name, umode_t mode)
 {
 	struct rdtgroup *rdtgrp;
@@ -2874,8 +2877,7 @@ static int rdtgroup_mkdir_ctrl_mon(struct kernfs_node *parent_kn,
 	u32 closid;
 	int ret;
 
-	ret = mkdir_rdt_prepare(parent_kn, prgrp_kn, name, mode, RDTCTRL_GROUP,
-				&rdtgrp);
+	ret = mkdir_rdt_prepare(parent_kn, name, mode, RDTCTRL_GROUP, &rdtgrp);
 	if (ret)
 		return ret;
 
@@ -2900,7 +2902,7 @@ static int rdtgroup_mkdir_ctrl_mon(struct kernfs_node *parent_kn,
 		 * Create an empty mon_groups directory to hold the subset
 		 * of tasks and cpus to monitor.
 		 */
-		ret = mongroup_create_dir(kn, NULL, "mon_groups", NULL);
+		ret = mongroup_create_dir(kn, rdtgrp, "mon_groups", NULL);
 		if (ret) {
 			rdt_last_cmd_puts("kernfs subdir error\n");
 			goto out_del_list;
@@ -2916,7 +2918,7 @@ out_id_free:
 out_common_fail:
 	mkdir_rdt_prepare_clean(rdtgrp);
 out_unlock:
-	rdtgroup_kn_unlock(prgrp_kn);
+	rdtgroup_kn_unlock(parent_kn);
 	return ret;
 }
 
@@ -2949,14 +2951,14 @@ static int rdtgroup_mkdir(struct kernfs_node *parent_kn, const char *name,
 	 * subdirectory
 	 */
 	if (rdt_alloc_capable && parent_kn == rdtgroup_default.kn)
-		return rdtgroup_mkdir_ctrl_mon(parent_kn, parent_kn, name, mode);
+		return rdtgroup_mkdir_ctrl_mon(parent_kn, name, mode);
 
 	/*
 	 * If RDT monitoring is supported and the parent directory is a valid
 	 * "mon_groups" directory, add a monitoring subdirectory.
 	 */
 	if (rdt_mon_capable && is_mon_groups(parent_kn, name))
-		return rdtgroup_mkdir_mon(parent_kn, parent_kn->parent, name, mode);
+		return rdtgroup_mkdir_mon(parent_kn, name, mode);
 
 	return -EPERM;
 }
@@ -3042,13 +3044,13 @@ static int rdtgroup_rmdir_ctrl(struct kernfs_node *kn, struct rdtgroup *rdtgrp,
 	closid_free(rdtgrp->closid);
 	free_rmid(rdtgrp->mon.rmid);
 
+	rdtgroup_ctrl_remove(kn, rdtgrp);
+
 	/*
 	 * Free all the child monitor group rmids.
 	 */
 	free_all_child_rdtgrp(rdtgrp);
 
-	rdtgroup_ctrl_remove(kn, rdtgrp);
-
 	return 0;
 }