Merge tag 'perf-urgent-for-mingo-5.5-20191216' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Pull perf/urgent fixes:

perf top:

 Arnaldo Carvalho de Melo:

 - Do not bail out when perf_env__read_cpuid() returns ENOSYS, which
   has been reported happening on aarch64.

perf metricgroup:

  Kajol Jain:

  - Fix printing event names of metric group with multiple events

vendor events:

x86:

  Ravi Bangoria:

  - Fix Kernel_Utilization metric.

s390:

  Ed Maste:

  - Fix counter long description for DTLB1_GPAGE_WRITES and L1D_RO_EXCL_WRITES.

perf header:

  Michael Petlan:

  - Fix false warning when there are no duplicate cache entries

libtraceevent:

  Sudip Mukherjee:

  - Allow custom libdir path

API headers:

  Arnaldo Carvalho de Melo:

  - Sync linux/kvm.h with the kernel sources.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 17 insertions, 20 deletions

diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index 64e9ee1b129e..074e9585c699 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -138,8 +138,12 @@ static int proc_getattr(const struct path *path, struct kstat *stat,
 {
 	struct inode *inode = d_inode(path->dentry);
 	struct proc_dir_entry *de = PDE(inode);
-	if (de && de->nlink)
-		set_nlink(inode, de->nlink);
+	if (de) {
+		nlink_t nlink = READ_ONCE(de->nlink);
+		if (nlink > 0) {
+			set_nlink(inode, nlink);
+		}
+	}
 
 	generic_fillattr(inode, stat);
 	return 0;
@@ -159,7 +163,6 @@ static int __xlate_proc_name(const char *name, struct proc_dir_entry **ret,
 {
 	const char     		*cp = name, *next;
 	struct proc_dir_entry	*de;
-	unsigned int		len;
 
 	de = *ret;
 	if (!de)
@@ -170,13 +173,12 @@ static int __xlate_proc_name(const char *name, struct proc_dir_entry **ret,
 		if (!next)
 			break;
 
-		len = next - cp;
-		de = pde_subdir_find(de, cp, len);
+		de = pde_subdir_find(de, cp, next - cp);
 		if (!de) {
 			WARN(1, "name '%s'\n", name);
 			return -ENOENT;
 		}
-		cp += len + 1;
+		cp = next + 1;
 	}
 	*residual = cp;
 	*ret = de;
@@ -362,6 +364,7 @@ struct proc_dir_entry *proc_register(struct proc_dir_entry *dir,
 		write_unlock(&proc_subdir_lock);
 		goto out_free_inum;
 	}
+	dir->nlink++;
 	write_unlock(&proc_subdir_lock);
 
 	return dp;
@@ -472,10 +475,7 @@ struct proc_dir_entry *proc_mkdir_data(const char *name, umode_t mode,
 		ent->data = data;
 		ent->proc_fops = &proc_dir_operations;
 		ent->proc_iops = &proc_dir_inode_operations;
-		parent->nlink++;
 		ent = proc_register(parent, ent);
-		if (!ent)
-			parent->nlink--;
 	}
 	return ent;
 }
@@ -505,10 +505,7 @@ struct proc_dir_entry *proc_create_mount_point(const char *name)
 		ent->data = NULL;
 		ent->proc_fops = NULL;
 		ent->proc_iops = NULL;
-		parent->nlink++;
 		ent = proc_register(parent, ent);
-		if (!ent)
-			parent->nlink--;
 	}
 	return ent;
 }
@@ -666,8 +663,12 @@ void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
 	len = strlen(fn);
 
 	de = pde_subdir_find(parent, fn, len);
-	if (de)
+	if (de) {
 		rb_erase(&de->subdir_node, &parent->subdir);
+		if (S_ISDIR(de->mode)) {
+			parent->nlink--;
+		}
+	}
 	write_unlock(&proc_subdir_lock);
 	if (!de) {
 		WARN(1, "name '%s'\n", name);
@@ -676,9 +677,6 @@ void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
 
 	proc_entry_rundown(de);
 
-	if (S_ISDIR(de->mode))
-		parent->nlink--;
-	de->nlink = 0;
 	WARN(pde_subdir_first(de),
 	     "%s: removing non-empty directory '%s/%s', leaking at least '%s'\n",
 	     __func__, de->parent->name, de->name, pde_subdir_first(de)->name);
@@ -714,13 +712,12 @@ int remove_proc_subtree(const char *name, struct proc_dir_entry *parent)
 			de = next;
 			continue;
 		}
-		write_unlock(&proc_subdir_lock);
-
-		proc_entry_rundown(de);
 		next = de->parent;
 		if (S_ISDIR(de->mode))
 			next->nlink--;
-		de->nlink = 0;
+		write_unlock(&proc_subdir_lock);
+
+		proc_entry_rundown(de);
 		if (de == root)
 			break;
 		pde_put(de);