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[209.132.180.67]) by mx.google.com with ESMTP id d6si12933424oic.86.2019.12.17.14.18.31; Tue, 17 Dec 2019 14:18:32 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727050AbfLQWSa (ORCPT + 27 others); Tue, 17 Dec 2019 17:18:30 -0500 Received: from mout.kundenserver.de ([212.227.17.13]:55579 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726801AbfLQWR5 (ORCPT ); Tue, 17 Dec 2019 17:17:57 -0500 Received: from threadripper.lan ([149.172.19.189]) by mrelayeu.kundenserver.de (mreue108 [212.227.15.145]) with ESMTPA (Nemesis) id 1MRCBm-1iMMMC1ATk-00NAX4; Tue, 17 Dec 2019 23:17:32 +0100 From: Arnd Bergmann To: Jens Axboe , "James E.J. Bottomley" , "Martin K. Petersen" Cc: linux-scsi@vger.kernel.org, linux-block@vger.kernel.org, y2038@lists.linaro.org, linux-kernel@vger.kernel.org, Christoph Hellwig , Ben Hutchings , linux-doc@vger.kernel.org, corbet@lwn.net, viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org, Arnd Bergmann Subject: [PATCH v2 20/27] compat_ioctl: simplify the implementation Date: Tue, 17 Dec 2019 23:17:01 +0100 Message-Id: <20191217221708.3730997-21-arnd@arndb.de> X-Mailer: git-send-email 2.20.0 In-Reply-To: <20191217221708.3730997-1-arnd@arndb.de> References: <20191217221708.3730997-1-arnd@arndb.de> MIME-Version: 1.0 X-Provags-ID: V03:K1:uK/YvNPT87O8gnoGWXh+F6Kwe06h+iVKNBQ7Vn492sB4NIm5fiO u8phscXPcsvZTLm/r6hUxiXDYINp6z+whQ1Kudg6IF96I27vCuUYSzL5m5paSXGTuUhVM67 783MX/6yKk1S7cJuTYhsnTyaN2T3Gikmuj1K9bzg4mqhdupgj1VF45J8exygF1mRvh7Khau s2UeQsmlK13ufWeKFxOLA== X-Spam-Flag: NO X-UI-Out-Filterresults: notjunk:1; V03:K0:enayNnzw2bY=:vxJr0zRZN5ttbUOCvy6+qe fo2wmFEaqJxAjt+Uqf3aCl9PpBwrGBXg7NF1bjjsxL3elMwpKU8EXa+6q8gLmkR2OCuv2s1aP 0sJFtYHrnUiGOfWpErlI+70B/6NM9rdPn+aKlGOD9Ob4gIIjIJ0bUVWcta5nut4HWg8QkiGyJ pV5CS1m3ZQMHpiMlNKmuA9Xd/uPT3oICXmtFEJBs7EcAzayCFhZdoXLajzLG+JPBAoYiE0BrA CQjBJ604Z98+aNfysExq3uUQKUu3ALpOzPB4GNTO1FCf3+ZMyGhARyXsjwdkYJr5QY0sPiKPu /3w2ZWx0bI3n30YePES8AesJ2Sk9FQYyMZIyUnI32CxNwJuVnp/ivJB7lTwSPp+7Nxw4ItMWH KGoO4wVkjmOZQAWhNpmcqLTCRKqLi2efjJWM9Lzcj9yPq+rNT31461M/KU/xyXznWJHKC0gs+ lUUH7Xt8xYJVfECf2MU4mwnnGbGDic0LxVXfPFGxtU/OmvxIrHDpqChzmz1Dp3T/FedGvuWda Jv1jAcAdivxNqSvjoqdK7sdvnBivzWvF3axmubM4LbSfAnh/D+bBFI/M4YYdXecwnN4IOCg3g 4dMa6xcR24YDKz4Rx0/qOftVjLb65DIPx79dpf86XSx6fWoOTmrJSE7b+g/2H2MrgVM+5fCj/ vG3V5ALBDGmkFfVrX4z3jRqcRFU/jiE2PytJMv3xVzoSvfiMPBI9mRnHFUTPETM8kk6fkpWJN 7ht0v41VoSm08w9B6Yhlbr0Ngh27Vls0LFT/uzzklooVGg/lnHKwXM6Ik76tiZybo2AdJ1M8H qIkrTFBpyQOjItD1QsZ2/DjmHkmDnSCuVfr7f7seSKSY0+J86+8ugV2f48ieJ00lZxntTu/Tu pQoNPCjuXQatKrHZfnEQ== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Now that both native and compat ioctl syscalls are in the same file, a couple of simplifications can be made, bringing the implementation closer together: - do_vfs_ioctl(), ioctl_preallocate(), and compat_ioctl_preallocate() can become static, allowing the compiler to optimize better - slightly update the coding style for consistency between the functions. - rather than listing each command in two switch statements for the compat case, just call a single function that has all the common commands. As a side-effect, FS_IOC_RESVSP/FS_IOC_RESVSP64 are now available to x86 compat tasks, along with FS_IOC_RESVSP_32/FS_IOC_RESVSP64_32. This is harmless for i386 emulation, and can be considered a bugfix for x32 emulation, which never supported these in the past. Signed-off-by: Arnd Bergmann --- fs/internal.h | 6 -- fs/ioctl.c | 157 +++++++++++++++++------------------------ include/linux/falloc.h | 2 - include/linux/fs.h | 4 -- 4 files changed, 64 insertions(+), 105 deletions(-) -- 2.20.0 diff --git a/fs/internal.h b/fs/internal.h index 4a7da1df573d..d46247850ad7 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -180,11 +180,5 @@ extern void mnt_pin_kill(struct mount *m); */ extern const struct dentry_operations ns_dentry_operations; -/* - * fs/ioctl.c - */ -extern int do_vfs_ioctl(struct file *file, unsigned int fd, unsigned int cmd, - unsigned long arg); - /* direct-io.c: */ int sb_init_dio_done_wq(struct super_block *sb); diff --git a/fs/ioctl.c b/fs/ioctl.c index 8f22f7817edb..7c9a5df5a597 100644 --- a/fs/ioctl.c +++ b/fs/ioctl.c @@ -467,7 +467,7 @@ EXPORT_SYMBOL(generic_block_fiemap); * Only the l_start, l_len and l_whence fields of the 'struct space_resv' * are used here, rest are ignored. */ -int ioctl_preallocate(struct file *filp, int mode, void __user *argp) +static int ioctl_preallocate(struct file *filp, int mode, void __user *argp) { struct inode *inode = file_inode(filp); struct space_resv sr; @@ -495,8 +495,8 @@ int ioctl_preallocate(struct file *filp, int mode, void __user *argp) /* on ia32 l_start is on a 32-bit boundary */ #if defined CONFIG_COMPAT && defined(CONFIG_X86_64) /* just account for different alignment */ -int compat_ioctl_preallocate(struct file *file, int mode, - struct space_resv_32 __user *argp) +static int compat_ioctl_preallocate(struct file *file, int mode, + struct space_resv_32 __user *argp) { struct inode *inode = file_inode(file); struct space_resv_32 sr; @@ -521,11 +521,9 @@ int compat_ioctl_preallocate(struct file *file, int mode, } #endif -static int file_ioctl(struct file *filp, unsigned int cmd, - unsigned long arg) +static int file_ioctl(struct file *filp, unsigned int cmd, int __user *p) { struct inode *inode = file_inode(filp); - int __user *p = (int __user *)arg; switch (cmd) { case FIBMAP: @@ -542,7 +540,7 @@ static int file_ioctl(struct file *filp, unsigned int cmd, return ioctl_preallocate(filp, FALLOC_FL_ZERO_RANGE, p); } - return vfs_ioctl(filp, cmd, arg); + return -ENOIOCTLCMD; } static int ioctl_fionbio(struct file *filp, int __user *argp) @@ -661,53 +659,48 @@ static int ioctl_file_dedupe_range(struct file *file, } /* - * When you add any new common ioctls to the switches above and below - * please update compat_sys_ioctl() too. - * * do_vfs_ioctl() is not for drivers and not intended to be EXPORT_SYMBOL()'d. * It's just a simple helper for sys_ioctl and compat_sys_ioctl. + * + * When you add any new common ioctls to the switches above and below, + * please ensure they have compatible arguments in compat mode. */ -int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd, - unsigned long arg) +static int do_vfs_ioctl(struct file *filp, unsigned int fd, + unsigned int cmd, unsigned long arg) { - int error = 0; void __user *argp = (void __user *)arg; struct inode *inode = file_inode(filp); switch (cmd) { case FIOCLEX: set_close_on_exec(fd, 1); - break; + return 0; case FIONCLEX: set_close_on_exec(fd, 0); - break; + return 0; case FIONBIO: - error = ioctl_fionbio(filp, argp); - break; + return ioctl_fionbio(filp, argp); case FIOASYNC: - error = ioctl_fioasync(fd, filp, argp); - break; + return ioctl_fioasync(fd, filp, argp); case FIOQSIZE: if (S_ISDIR(inode->i_mode) || S_ISREG(inode->i_mode) || S_ISLNK(inode->i_mode)) { loff_t res = inode_get_bytes(inode); - error = copy_to_user(argp, &res, sizeof(res)) ? - -EFAULT : 0; - } else - error = -ENOTTY; - break; + return copy_to_user(argp, &res, sizeof(res)) ? + -EFAULT : 0; + } + + return -ENOTTY; case FIFREEZE: - error = ioctl_fsfreeze(filp); - break; + return ioctl_fsfreeze(filp); case FITHAW: - error = ioctl_fsthaw(filp); - break; + return ioctl_fsthaw(filp); case FS_IOC_FIEMAP: return ioctl_fiemap(filp, argp); @@ -716,6 +709,7 @@ int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd, /* anon_bdev filesystems may not have a block size */ if (!inode->i_sb->s_blocksize) return -EINVAL; + return put_user(inode->i_sb->s_blocksize, (int __user *)argp); case FICLONE: @@ -729,24 +723,30 @@ int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd, default: if (S_ISREG(inode->i_mode)) - error = file_ioctl(filp, cmd, arg); - else - error = vfs_ioctl(filp, cmd, arg); + return file_ioctl(filp, cmd, argp); break; } - return error; + + return -ENOIOCTLCMD; } int ksys_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg) { - int error; struct fd f = fdget(fd); + int error; if (!f.file) return -EBADF; + error = security_file_ioctl(f.file, cmd, arg); - if (!error) - error = do_vfs_ioctl(f.file, fd, cmd, arg); + if (error) + goto out; + + error = do_vfs_ioctl(f.file, fd, cmd, arg); + if (error == -ENOIOCTLCMD) + error = vfs_ioctl(f.file, cmd, arg); + +out: fdput(f); return error; } @@ -790,92 +790,63 @@ long compat_ptr_ioctl(struct file *file, unsigned int cmd, unsigned long arg) EXPORT_SYMBOL(compat_ptr_ioctl); COMPAT_SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, - compat_ulong_t, arg32) + compat_ulong_t, arg) { - unsigned long arg = arg32; struct fd f = fdget(fd); - int error = -EBADF; + int error; + if (!f.file) - goto out; + return -EBADF; /* RED-PEN how should LSM module know it's handling 32bit? */ error = security_file_ioctl(f.file, cmd, arg); if (error) - goto out_fput; + goto out; switch (cmd) { - /* these are never seen by ->ioctl(), no argument or int argument */ - case FIOCLEX: - case FIONCLEX: - case FIFREEZE: - case FITHAW: + /* FICLONE takes an int argument, so don't use compat_ptr() */ case FICLONE: - goto do_ioctl; - /* these are never seen by ->ioctl(), pointer argument */ - case FIONBIO: - case FIOASYNC: - case FIOQSIZE: - case FS_IOC_FIEMAP: - case FIGETBSZ: - case FICLONERANGE: - case FIDEDUPERANGE: - goto found_handler; - /* - * The next group is the stuff handled inside file_ioctl(). - * For regular files these never reach ->ioctl(); for - * devices, sockets, etc. they do and one (FIONREAD) is - * even accepted in some cases. In all those cases - * argument has the same type, so we can handle these - * here, shunting them towards do_vfs_ioctl(). - * ->compat_ioctl() will never see any of those. - */ - /* pointer argument, never actually handled by ->ioctl() */ - case FIBMAP: - goto found_handler; - /* handled by some ->ioctl(); always a pointer to int */ - case FIONREAD: - goto found_handler; - /* these get messy on amd64 due to alignment differences */ + error = ioctl_file_clone(f.file, arg, 0, 0, 0); + break; + #if defined(CONFIG_X86_64) + /* these get messy on amd64 due to alignment differences */ case FS_IOC_RESVSP_32: case FS_IOC_RESVSP64_32: error = compat_ioctl_preallocate(f.file, 0, compat_ptr(arg)); - goto out_fput; + break; case FS_IOC_UNRESVSP_32: case FS_IOC_UNRESVSP64_32: error = compat_ioctl_preallocate(f.file, FALLOC_FL_PUNCH_HOLE, compat_ptr(arg)); - goto out_fput; + break; case FS_IOC_ZERO_RANGE_32: error = compat_ioctl_preallocate(f.file, FALLOC_FL_ZERO_RANGE, compat_ptr(arg)); - goto out_fput; -#else - case FS_IOC_RESVSP: - case FS_IOC_RESVSP64: - case FS_IOC_UNRESVSP: - case FS_IOC_UNRESVSP64: - case FS_IOC_ZERO_RANGE: - goto found_handler; + break; #endif + /* + * everything else in do_vfs_ioctl() takes either a compatible + * pointer argument or no argument -- call it with a modified + * argument. + */ default: - if (f.file->f_op->compat_ioctl) { + error = do_vfs_ioctl(f.file, fd, cmd, + (unsigned long)compat_ptr(arg)); + if (error != -ENOIOCTLCMD) + break; + + if (f.file->f_op->compat_ioctl) error = f.file->f_op->compat_ioctl(f.file, cmd, arg); - if (error != -ENOIOCTLCMD) - goto out_fput; - } - error = -ENOTTY; - goto out_fput; + if (error == -ENOIOCTLCMD) + error = -ENOTTY; + break; } - found_handler: - arg = (unsigned long)compat_ptr(arg); - do_ioctl: - error = do_vfs_ioctl(f.file, fd, cmd, arg); - out_fput: - fdput(f); out: + fdput(f); + return error; } #endif diff --git a/include/linux/falloc.h b/include/linux/falloc.h index 8bf3d79f3e82..f3f0b97b1675 100644 --- a/include/linux/falloc.h +++ b/include/linux/falloc.h @@ -51,8 +51,6 @@ struct space_resv_32 { #define FS_IOC_UNRESVSP64_32 _IOW ('X', 43, struct space_resv_32) #define FS_IOC_ZERO_RANGE_32 _IOW ('X', 57, struct space_resv_32) -int compat_ioctl_preallocate(struct file *, int, struct space_resv_32 __user *); - #endif #endif /* _FALLOC_H_ */ diff --git a/include/linux/fs.h b/include/linux/fs.h index 98e0349adb52..daf570bca42a 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2552,10 +2552,6 @@ extern int finish_open(struct file *file, struct dentry *dentry, int (*open)(struct inode *, struct file *)); extern int finish_no_open(struct file *file, struct dentry *dentry); -/* fs/ioctl.c */ - -extern int ioctl_preallocate(struct file *filp, int mode, void __user *argp); - /* fs/dcache.c */ extern void __init vfs_caches_init_early(void); extern void __init vfs_caches_init(void);