The patch below does not apply to the 6.8-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@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.8.y git checkout FETCH_HEAD git cherry-pick -x d53891d348ac3eceaf48f4732a1f4f5c0e0a55ce # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024051624-efficient-jingle-fc71@gregkh' --subject-prefix 'PATCH 6.8.y' HEAD^..

Possible dependencies:

d53891d348ac ("eventfs: Do not differentiate the toplevel events directory")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From d53891d348ac3eceaf48f4732a1f4f5c0e0a55ce Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" rostedt@goodmis.org Date: Thu, 2 May 2024 16:08:25 -0400 Subject: [PATCH] eventfs: Do not differentiate the toplevel events directory

The toplevel events directory is really no different than the events directory of instances. Having the two be different caused inconsistencies and made it harder to fix the permissions bugs.

Make all events directories act the same.

Link: https://lore.kernel.org/linux-trace-kernel/20240502200905.846448710@goodmis....

Cc: stable@vger.kernel.org Cc: Masami Hiramatsu mhiramat@kernel.org Cc: Mark Rutland mark.rutland@arm.com Cc: Mathieu Desnoyers mathieu.desnoyers@efficios.com Cc: Andrew Morton akpm@linux-foundation.org Fixes: 8186fff7ab649 ("tracefs/eventfs: Use root and instance inodes as default ownership") Signed-off-by: Steven Rostedt (Google) rostedt@goodmis.org

diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index 15a2a9c3c62b..9dacf65c0b6e 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -68,7 +68,6 @@ enum { EVENTFS_SAVE_MODE = BIT(16), EVENTFS_SAVE_UID = BIT(17), EVENTFS_SAVE_GID = BIT(18), - EVENTFS_TOPLEVEL = BIT(19), };

#define EVENTFS_MODE_MASK (EVENTFS_SAVE_MODE - 1) @@ -239,14 +238,10 @@ static int eventfs_set_attr(struct mnt_idmap *idmap, struct dentry *dentry, return ret; }

-static void update_top_events_attr(struct eventfs_inode *ei, struct super_block *sb) +static void update_events_attr(struct eventfs_inode *ei, struct super_block *sb) { struct inode *root;

- /* Only update if the "events" was on the top level */ - if (!ei || !(ei->attr.mode & EVENTFS_TOPLEVEL)) - return; - /* Get the tracefs root inode. */ root = d_inode(sb->s_root); ei->attr.uid = root->i_uid; @@ -259,10 +254,10 @@ static void set_top_events_ownership(struct inode *inode) struct eventfs_inode *ei = ti->private;

/* The top events directory doesn't get automatically updated */ - if (!ei || !ei->is_events || !(ei->attr.mode & EVENTFS_TOPLEVEL)) + if (!ei || !ei->is_events) return;

- update_top_events_attr(ei, inode->i_sb); + update_events_attr(ei, inode->i_sb);

if (!(ei->attr.mode & EVENTFS_SAVE_UID)) inode->i_uid = ei->attr.uid; @@ -291,7 +286,7 @@ static int eventfs_permission(struct mnt_idmap *idmap, return generic_permission(idmap, inode, mask); }

-static const struct inode_operations eventfs_root_dir_inode_operations = { +static const struct inode_operations eventfs_dir_inode_operations = { .lookup = eventfs_root_lookup, .setattr = eventfs_set_attr, .getattr = eventfs_get_attr, @@ -359,7 +354,7 @@ static struct eventfs_inode *eventfs_find_events(struct dentry *dentry) // Walk upwards until you find the events inode } while (!ei->is_events);

- update_top_events_attr(ei, dentry->d_sb); + update_events_attr(ei, dentry->d_sb);

return ei; } @@ -465,7 +460,7 @@ static struct dentry *lookup_dir_entry(struct dentry *dentry, update_inode_attr(dentry, inode, &ei->attr, S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO);

- inode->i_op = &eventfs_root_dir_inode_operations; + inode->i_op = &eventfs_dir_inode_operations; inode->i_fop = &eventfs_file_operations;

/* All directories will have the same inode number */ @@ -845,14 +840,6 @@ struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry uid = d_inode(dentry->d_parent)->i_uid; gid = d_inode(dentry->d_parent)->i_gid;

- /* - * If the events directory is of the top instance, then parent - * is NULL. Set the attr.mode to reflect this and its permissions will - * default to the tracefs root dentry. - */ - if (!parent) - ei->attr.mode = EVENTFS_TOPLEVEL; - /* This is used as the default ownership of the files and directories */ ei->attr.uid = uid; ei->attr.gid = gid; @@ -861,13 +848,13 @@ struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry INIT_LIST_HEAD(&ei->list);

ti = get_tracefs(inode); - ti->flags |= TRACEFS_EVENT_INODE | TRACEFS_EVENT_TOP_INODE; + ti->flags |= TRACEFS_EVENT_INODE; ti->private = ei;

inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO; inode->i_uid = uid; inode->i_gid = gid; - inode->i_op = &eventfs_root_dir_inode_operations; + inode->i_op = &eventfs_dir_inode_operations; inode->i_fop = &eventfs_file_operations;

dentry->d_fsdata = get_ei(ei); diff --git a/fs/tracefs/internal.h b/fs/tracefs/internal.h index 29f0c999975b..f704d8348357 100644 --- a/fs/tracefs/internal.h +++ b/fs/tracefs/internal.h @@ -4,10 +4,9 @@

enum { TRACEFS_EVENT_INODE = BIT(1), - TRACEFS_EVENT_TOP_INODE = BIT(2), - TRACEFS_GID_PERM_SET = BIT(3), - TRACEFS_UID_PERM_SET = BIT(4), - TRACEFS_INSTANCE_INODE = BIT(5), + TRACEFS_GID_PERM_SET = BIT(2), + TRACEFS_UID_PERM_SET = BIT(3), + TRACEFS_INSTANCE_INODE = BIT(4), };

struct tracefs_inode {