Merge tag 'kvmarm-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 updates for 6.12

* New features:

  - Add a Stage-2 page table dumper, reusing the main ptdump
    infrastructure, and allowing easier debugging of the our
    page-table infrastructure

  - Add FP8 support to the KVM/arm64 floating point handling.

  - Add NV support for the AT family of instructions, which mostly
    results in adding a page table walker that deals with most of the
    complexity of the architecture.

* Improvements, fixes and cleanups:

  - Add selftest checks for a bunch of timer emulation corner cases

  - Fix the multiple of cases where KVM/arm64 doesn't correctly handle
    the guest trying to use a GICv3 that isn't advertised

  - Remove REG_HIDDEN_USER from the sysreg infrastructure, making
    things little more simple

  - Prevent MTE tags being restored by userspace if we are actively
    logging writes, as that's a recipe for disaster

  - Correct the refcount on a page that is not considered for MTE tag
    copying (such as a device)

  - Relax the synchronisation when walking a page table to split block
    mappings, moving it at the end the walk, as there is no need to
    perform it on every store.

  - Fix boundary check when transfering memory using FFA

  - Fix pKVM TLB invalidation, only affecting currently out of tree
    code but worth addressing for peace of mind

1 files changed, 24 insertions, 11 deletions

diff --git a/fs/libfs.c b/fs/libfs.c
index 8aa34870449f..02602d00939e 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -450,6 +450,14 @@ void simple_offset_destroy(struct offset_ctx *octx)
 	mtree_destroy(&octx->mt);
 }
 
+static int offset_dir_open(struct inode *inode, struct file *file)
+{
+	struct offset_ctx *ctx = inode->i_op->get_offset_ctx(inode);
+
+	file->private_data = (void *)ctx->next_offset;
+	return 0;
+}
+
 /**
  * offset_dir_llseek - Advance the read position of a directory descriptor
  * @file: an open directory whose position is to be updated
@@ -463,6 +471,9 @@ void simple_offset_destroy(struct offset_ctx *octx)
  */
 static loff_t offset_dir_llseek(struct file *file, loff_t offset, int whence)
 {
+	struct inode *inode = file->f_inode;
+	struct offset_ctx *ctx = inode->i_op->get_offset_ctx(inode);
+
 	switch (whence) {
 	case SEEK_CUR:
 		offset += file->f_pos;
@@ -476,7 +487,8 @@ static loff_t offset_dir_llseek(struct file *file, loff_t offset, int whence)
 	}
 
 	/* In this case, ->private_data is protected by f_pos_lock */
-	file->private_data = NULL;
+	if (!offset)
+		file->private_data = (void *)ctx->next_offset;
 	return vfs_setpos(file, offset, LONG_MAX);
 }
 
@@ -507,7 +519,7 @@ static bool offset_dir_emit(struct dir_context *ctx, struct dentry *dentry)
 			  inode->i_ino, fs_umode_to_dtype(inode->i_mode));
 }
 
-static void *offset_iterate_dir(struct inode *inode, struct dir_context *ctx)
+static void offset_iterate_dir(struct inode *inode, struct dir_context *ctx, long last_index)
 {
 	struct offset_ctx *octx = inode->i_op->get_offset_ctx(inode);
 	struct dentry *dentry;
@@ -515,17 +527,21 @@ static void *offset_iterate_dir(struct inode *inode, struct dir_context *ctx)
 	while (true) {
 		dentry = offset_find_next(octx, ctx->pos);
 		if (!dentry)
-			return ERR_PTR(-ENOENT);
+			return;
+
+		if (dentry2offset(dentry) >= last_index) {
+			dput(dentry);
+			return;
+		}
 
 		if (!offset_dir_emit(ctx, dentry)) {
 			dput(dentry);
-			break;
+			return;
 		}
 
 		ctx->pos = dentry2offset(dentry) + 1;
 		dput(dentry);
 	}
-	return NULL;
 }
 
 /**
@@ -552,22 +568,19 @@ static void *offset_iterate_dir(struct inode *inode, struct dir_context *ctx)
 static int offset_readdir(struct file *file, struct dir_context *ctx)
 {
 	struct dentry *dir = file->f_path.dentry;
+	long last_index = (long)file->private_data;
 
 	lockdep_assert_held(&d_inode(dir)->i_rwsem);
 
 	if (!dir_emit_dots(file, ctx))
 		return 0;
 
-	/* In this case, ->private_data is protected by f_pos_lock */
-	if (ctx->pos == DIR_OFFSET_MIN)
-		file->private_data = NULL;
-	else if (file->private_data == ERR_PTR(-ENOENT))
-		return 0;
-	file->private_data = offset_iterate_dir(d_inode(dir), ctx);
+	offset_iterate_dir(d_inode(dir), ctx, last_index);
 	return 0;
 }
 
 const struct file_operations simple_offset_dir_operations = {
+	.open		= offset_dir_open,
 	.llseek		= offset_dir_llseek,
 	.iterate_shared	= offset_readdir,
 	.read		= generic_read_dir,