From: Jan Kara <jack@suse.cz>
To: Vasily Averin <vvs@openvz.org>
Cc: Christoph Hellwig <hch@infradead.org>, Jan Kara <jack@suse.cz>,
Christian Brauner <brauner@kernel.org>,
kernel@openvz.org, linux-kernel@vger.kernel.org,
Alexander Viro <viro@zeniv.linux.org.uk>,
Amir Goldstein <amir73il@gmail.com>,
Matthew Bobrowski <repnop@google.com>,
linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH v2] sparse: fix incorrect fmode_t casts
Date: Wed, 18 May 2022 13:12:02 +0200 [thread overview]
Message-ID: <20220518111202.33qkxrfui7o7bb2o@quack3.lan> (raw)
In-Reply-To: <86e82d40-0952-e76f-aac5-53abe48ec770@openvz.org>
On Wed 18-05-22 13:49:07, Vasily Averin wrote:
> Fixes sparce warnings:
> fs/notify/fanotify/fanotify_user.c:267:63: sparse:
> warning: restricted fmode_t degrades to integer
> fs/notify/fanotify/fanotify_user.c:1351:28: sparse:
> warning: restricted fmode_t degrades to integer
> fs/proc/base.c:2240:25: sparse: warning: cast to restricted fmode_t
> fs/proc/base.c:2297:42: sparse: warning: cast from restricted fmode_t
> fs/proc/base.c:2394:48: sparse: warning: cast from restricted fmode_t
> fs/open.c:1024:21: sparse: warning: restricted fmode_t degrades to integer
>
> Signed-off-by: Vasily Averin <vvs@openvz.org>
Feel free to add:
Acked-by: Jan Kara <jack@suse.cz>
for the fanotify bits.
Honza
> ---
> v2:
> 1) use __FMODE_NONOTIFY instead of FMODE_NONOTIFY
> 2) introduced fmode_instantiate_de/encode helpers
> thanks Christoph Hellwig for the hints
> ---
> fs/notify/fanotify/fanotify_user.c | 4 ++--
> fs/open.c | 2 +-
> fs/proc/base.c | 21 ++++++++++++++++-----
> 3 files changed, 19 insertions(+), 8 deletions(-)
>
> diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
> index 9b32b76a9c30..2bec3b612618 100644
> --- a/fs/notify/fanotify/fanotify_user.c
> +++ b/fs/notify/fanotify/fanotify_user.c
> @@ -264,7 +264,7 @@ static int create_fd(struct fsnotify_group *group, struct path *path,
> * originally opened O_WRONLY.
> */
> new_file = dentry_open(path,
> - group->fanotify_data.f_flags | FMODE_NONOTIFY,
> + group->fanotify_data.f_flags | __FMODE_NONOTIFY,
> current_cred());
> if (IS_ERR(new_file)) {
> /*
> @@ -1348,7 +1348,7 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
> (!(fid_mode & FAN_REPORT_NAME) || !(fid_mode & FAN_REPORT_FID)))
> return -EINVAL;
>
> - f_flags = O_RDWR | FMODE_NONOTIFY;
> + f_flags = O_RDWR | __FMODE_NONOTIFY;
> if (flags & FAN_CLOEXEC)
> f_flags |= O_CLOEXEC;
> if (flags & FAN_NONBLOCK)
> diff --git a/fs/open.c b/fs/open.c
> index 1315253e0247..386c52e4c3b1 100644
> --- a/fs/open.c
> +++ b/fs/open.c
> @@ -1021,7 +1021,7 @@ inline struct open_how build_open_how(int flags, umode_t mode)
> inline int build_open_flags(const struct open_how *how, struct open_flags *op)
> {
> u64 flags = how->flags;
> - u64 strip = FMODE_NONOTIFY | O_CLOEXEC;
> + u64 strip = __FMODE_NONOTIFY | O_CLOEXEC;
> int lookup_flags = 0;
> int acc_mode = ACC_MODE(flags);
>
> diff --git a/fs/proc/base.c b/fs/proc/base.c
> index c1031843cc6a..b8ed41eb5784 100644
> --- a/fs/proc/base.c
> +++ b/fs/proc/base.c
> @@ -2233,11 +2233,21 @@ static const struct inode_operations proc_map_files_link_inode_operations = {
> .setattr = proc_setattr,
> };
>
> +static fmode_t fmode_instantiate_decode(const void *ptr)
> +{
> + return (__force fmode_t)(unsigned long)ptr;
> +}
> +
> +static void *fmode_instantiate_encode(fmode_t fmode)
> +{
> + return (void *)(__force unsigned long)fmode;
> +}
> +
> static struct dentry *
> proc_map_files_instantiate(struct dentry *dentry,
> struct task_struct *task, const void *ptr)
> {
> - fmode_t mode = (fmode_t)(unsigned long)ptr;
> + fmode_t mode = fmode_instantiate_decode(ptr);
> struct proc_inode *ei;
> struct inode *inode;
>
> @@ -2292,10 +2302,11 @@ static struct dentry *proc_map_files_lookup(struct inode *dir,
> if (!vma)
> goto out_no_vma;
>
> - if (vma->vm_file)
> - result = proc_map_files_instantiate(dentry, task,
> - (void *)(unsigned long)vma->vm_file->f_mode);
> + if (vma->vm_file) {
> + void *ptr = fmode_instantiate_encode(vma->vm_file->f_mode);
>
> + result = proc_map_files_instantiate(dentry, task, ptr);
> + }
> out_no_vma:
> mmap_read_unlock(mm);
> out_put_mm:
> @@ -2391,7 +2402,7 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx)
> buf, len,
> proc_map_files_instantiate,
> task,
> - (void *)(unsigned long)p->mode))
> + (void *)(__force unsigned long)p->mode))
> break;
> ctx->pos++;
> }
> --
> 2.31.1
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
next prev parent reply other threads:[~2022-05-18 11:12 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-14 10:22 [PATCH] sparse: use force attribute for fmode_t casts Vasily Averin
2022-05-16 11:18 ` Jan Kara
2022-05-16 11:47 ` Christian Brauner
2022-05-17 6:38 ` Christoph Hellwig
2022-05-18 10:49 ` [PATCH v2] sparse: fix incorrect " Vasily Averin
2022-05-18 11:12 ` Jan Kara [this message]
2022-05-18 13:22 ` Christoph Hellwig
2022-05-18 14:44 ` Christian Brauner
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