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From: Christoph Hellwig <hch@lst.de>
To: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Jens Axboe <axboe@kernel.dk>, Arnd Bergmann <arnd@arndb.de>,
	David Howells <dhowells@redhat.com>,
	David Laight <David.Laight@aculab.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org,
	linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
	linux-s390@vger.kernel.org, sparclinux@vger.kernel.org,
	linux-block@vger.kernel.org, linux-scsi@vger.kernel.org,
	linux-fsdevel@vger.kernel.org, linux-aio@kvack.org,
	io-uring@vger.kernel.org, linux-arch@vger.kernel.org,
	linux-mm@kvack.org, netdev@vger.kernel.org,
	keyrings@vger.kernel.org, linux-security-module@vger.kernel.org
Subject: [PATCH 5/9] fs: remove various compat readv/writev helpers
Date: Fri, 25 Sep 2020 06:51:42 +0200
Message-ID: <20200925045146.1283714-6-hch@lst.de> (raw)
In-Reply-To: <20200925045146.1283714-1-hch@lst.de>

Now that import_iovec handles compat iovecs as well, all the duplicated
code in the compat readv/writev helpers is not needed.  Remove them
and switch the compat syscall handlers to use the native helpers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/read_write.c        | 179 +++++++----------------------------------
 include/linux/compat.h |  20 ++---
 2 files changed, 40 insertions(+), 159 deletions(-)

diff --git a/fs/read_write.c b/fs/read_write.c
index 0a68037580b455..eab427b7cc0a3f 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1068,226 +1068,107 @@ SYSCALL_DEFINE6(pwritev2, unsigned long, fd, const struct iovec __user *, vec,
 	return do_pwritev(fd, vec, vlen, pos, flags);
 }
 
+/*
+ * Various compat syscalls.  Note that they all pretend to take a native
+ * iovec - import_iovec will properly treat those as compat_iovecs based on
+ * in_compat_syscall().
+ */
 #ifdef CONFIG_COMPAT
-static size_t compat_readv(struct file *file,
-			   const struct compat_iovec __user *vec,
-			   unsigned long vlen, loff_t *pos, rwf_t flags)
-{
-	struct iovec iovstack[UIO_FASTIOV];
-	struct iovec *iov = iovstack;
-	struct iov_iter iter;
-	ssize_t ret;
-
-	ret = import_iovec(READ, (const struct iovec __user *)vec, vlen,
-			   UIO_FASTIOV, &iov, &iter);
-	if (ret >= 0) {
-		ret = do_iter_read(file, &iter, pos, flags);
-		kfree(iov);
-	}
-	if (ret > 0)
-		add_rchar(current, ret);
-	inc_syscr(current);
-	return ret;
-}
-
-static size_t do_compat_readv(compat_ulong_t fd,
-				 const struct compat_iovec __user *vec,
-				 compat_ulong_t vlen, rwf_t flags)
-{
-	struct fd f = fdget_pos(fd);
-	ssize_t ret;
-	loff_t pos;
-
-	if (!f.file)
-		return -EBADF;
-	pos = f.file->f_pos;
-	ret = compat_readv(f.file, vec, vlen, &pos, flags);
-	if (ret >= 0)
-		f.file->f_pos = pos;
-	fdput_pos(f);
-	return ret;
-
-}
-
 COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd,
-		const struct compat_iovec __user *,vec,
+		const struct iovec __user *, vec,
 		compat_ulong_t, vlen)
 {
-	return do_compat_readv(fd, vec, vlen, 0);
-}
-
-static long do_compat_preadv64(unsigned long fd,
-				  const struct compat_iovec __user *vec,
-				  unsigned long vlen, loff_t pos, rwf_t flags)
-{
-	struct fd f;
-	ssize_t ret;
-
-	if (pos < 0)
-		return -EINVAL;
-	f = fdget(fd);
-	if (!f.file)
-		return -EBADF;
-	ret = -ESPIPE;
-	if (f.file->f_mode & FMODE_PREAD)
-		ret = compat_readv(f.file, vec, vlen, &pos, flags);
-	fdput(f);
-	return ret;
+	return do_readv(fd, vec, vlen, 0);
 }
 
 #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64
 COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd,
-		const struct compat_iovec __user *,vec,
+		const struct iovec __user *, vec,
 		unsigned long, vlen, loff_t, pos)
 {
-	return do_compat_preadv64(fd, vec, vlen, pos, 0);
+	return do_preadv(fd, vec, vlen, pos, 0);
 }
 #endif
 
 COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd,
-		const struct compat_iovec __user *,vec,
+		const struct iovec __user *, vec,
 		compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
 {
 	loff_t pos = ((loff_t)pos_high << 32) | pos_low;
 
-	return do_compat_preadv64(fd, vec, vlen, pos, 0);
+	return do_preadv(fd, vec, vlen, pos, 0);
 }
 
 #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64V2
 COMPAT_SYSCALL_DEFINE5(preadv64v2, unsigned long, fd,
-		const struct compat_iovec __user *,vec,
+		const struct iovec __user *, vec,
 		unsigned long, vlen, loff_t, pos, rwf_t, flags)
 {
 	if (pos == -1)
-		return do_compat_readv(fd, vec, vlen, flags);
-
-	return do_compat_preadv64(fd, vec, vlen, pos, flags);
+		return do_readv(fd, vec, vlen, flags);
+	return do_preadv(fd, vec, vlen, pos, flags);
 }
 #endif
 
 COMPAT_SYSCALL_DEFINE6(preadv2, compat_ulong_t, fd,
-		const struct compat_iovec __user *,vec,
+		const struct iovec __user *, vec,
 		compat_ulong_t, vlen, u32, pos_low, u32, pos_high,
 		rwf_t, flags)
 {
 	loff_t pos = ((loff_t)pos_high << 32) | pos_low;
 
 	if (pos == -1)
-		return do_compat_readv(fd, vec, vlen, flags);
-
-	return do_compat_preadv64(fd, vec, vlen, pos, flags);
-}
-
-static size_t compat_writev(struct file *file,
-			    const struct compat_iovec __user *vec,
-			    unsigned long vlen, loff_t *pos, rwf_t flags)
-{
-	struct iovec iovstack[UIO_FASTIOV];
-	struct iovec *iov = iovstack;
-	struct iov_iter iter;
-	ssize_t ret;
-
-	ret = import_iovec(WRITE, (const struct iovec __user *)vec, vlen,
-			   UIO_FASTIOV, &iov, &iter);
-	if (ret >= 0) {
-		file_start_write(file);
-		ret = do_iter_write(file, &iter, pos, flags);
-		file_end_write(file);
-		kfree(iov);
-	}
-	if (ret > 0)
-		add_wchar(current, ret);
-	inc_syscw(current);
-	return ret;
-}
-
-static size_t do_compat_writev(compat_ulong_t fd,
-				  const struct compat_iovec __user* vec,
-				  compat_ulong_t vlen, rwf_t flags)
-{
-	struct fd f = fdget_pos(fd);
-	ssize_t ret;
-	loff_t pos;
-
-	if (!f.file)
-		return -EBADF;
-	pos = f.file->f_pos;
-	ret = compat_writev(f.file, vec, vlen, &pos, flags);
-	if (ret >= 0)
-		f.file->f_pos = pos;
-	fdput_pos(f);
-	return ret;
+		return do_readv(fd, vec, vlen, flags);
+	return do_preadv(fd, vec, vlen, pos, flags);
 }
 
 COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd,
-		const struct compat_iovec __user *, vec,
+		const struct iovec __user *, vec,
 		compat_ulong_t, vlen)
 {
-	return do_compat_writev(fd, vec, vlen, 0);
-}
-
-static long do_compat_pwritev64(unsigned long fd,
-				   const struct compat_iovec __user *vec,
-				   unsigned long vlen, loff_t pos, rwf_t flags)
-{
-	struct fd f;
-	ssize_t ret;
-
-	if (pos < 0)
-		return -EINVAL;
-	f = fdget(fd);
-	if (!f.file)
-		return -EBADF;
-	ret = -ESPIPE;
-	if (f.file->f_mode & FMODE_PWRITE)
-		ret = compat_writev(f.file, vec, vlen, &pos, flags);
-	fdput(f);
-	return ret;
+	return do_writev(fd, vec, vlen, 0);
 }
 
 #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64
 COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd,
-		const struct compat_iovec __user *,vec,
+		const struct iovec __user *, vec,
 		unsigned long, vlen, loff_t, pos)
 {
-	return do_compat_pwritev64(fd, vec, vlen, pos, 0);
+	return do_pwritev(fd, vec, vlen, pos, 0);
 }
 #endif
 
 COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd,
-		const struct compat_iovec __user *,vec,
+		const struct iovec __user *,vec,
 		compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
 {
 	loff_t pos = ((loff_t)pos_high << 32) | pos_low;
 
-	return do_compat_pwritev64(fd, vec, vlen, pos, 0);
+	return do_pwritev(fd, vec, vlen, pos, 0);
 }
 
 #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64V2
 COMPAT_SYSCALL_DEFINE5(pwritev64v2, unsigned long, fd,
-		const struct compat_iovec __user *,vec,
+		const struct iovec __user *, vec,
 		unsigned long, vlen, loff_t, pos, rwf_t, flags)
 {
 	if (pos == -1)
-		return do_compat_writev(fd, vec, vlen, flags);
-
-	return do_compat_pwritev64(fd, vec, vlen, pos, flags);
+		return do_writev(fd, vec, vlen, flags);
+	return do_pwritev(fd, vec, vlen, pos, flags);
 }
 #endif
 
 COMPAT_SYSCALL_DEFINE6(pwritev2, compat_ulong_t, fd,
-		const struct compat_iovec __user *,vec,
+		const struct iovec __user *,vec,
 		compat_ulong_t, vlen, u32, pos_low, u32, pos_high, rwf_t, flags)
 {
 	loff_t pos = ((loff_t)pos_high << 32) | pos_low;
 
 	if (pos == -1)
-		return do_compat_writev(fd, vec, vlen, flags);
-
-	return do_compat_pwritev64(fd, vec, vlen, pos, flags);
+		return do_writev(fd, vec, vlen, flags);
+	return do_pwritev(fd, vec, vlen, pos, flags);
 }
-
-#endif
+#endif /* CONFIG_COMPAT */
 
 static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
 		  	   size_t count, loff_t max)
diff --git a/include/linux/compat.h b/include/linux/compat.h
index b930de791ff16b..306ea7e1172d8d 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -546,25 +546,25 @@ asmlinkage long compat_sys_getdents(unsigned int fd,
 /* fs/read_write.c */
 asmlinkage long compat_sys_lseek(unsigned int, compat_off_t, unsigned int);
 asmlinkage ssize_t compat_sys_readv(compat_ulong_t fd,
-		const struct compat_iovec __user *vec, compat_ulong_t vlen);
+		const struct iovec __user *vec, compat_ulong_t vlen);
 asmlinkage ssize_t compat_sys_writev(compat_ulong_t fd,
-		const struct compat_iovec __user *vec, compat_ulong_t vlen);
+		const struct iovec __user *vec, compat_ulong_t vlen);
 /* No generic prototype for pread64 and pwrite64 */
 asmlinkage ssize_t compat_sys_preadv(compat_ulong_t fd,
-		const struct compat_iovec __user *vec,
+		const struct iovec __user *vec,
 		compat_ulong_t vlen, u32 pos_low, u32 pos_high);
 asmlinkage ssize_t compat_sys_pwritev(compat_ulong_t fd,
-		const struct compat_iovec __user *vec,
+		const struct iovec __user *vec,
 		compat_ulong_t vlen, u32 pos_low, u32 pos_high);
 #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64
 asmlinkage long compat_sys_preadv64(unsigned long fd,
-		const struct compat_iovec __user *vec,
+		const struct iovec __user *vec,
 		unsigned long vlen, loff_t pos);
 #endif
 
 #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64
 asmlinkage long compat_sys_pwritev64(unsigned long fd,
-		const struct compat_iovec __user *vec,
+		const struct iovec __user *vec,
 		unsigned long vlen, loff_t pos);
 #endif
 
@@ -800,20 +800,20 @@ asmlinkage long compat_sys_execveat(int dfd, const char __user *filename,
 		     const compat_uptr_t __user *argv,
 		     const compat_uptr_t __user *envp, int flags);
 asmlinkage ssize_t compat_sys_preadv2(compat_ulong_t fd,
-		const struct compat_iovec __user *vec,
+		const struct iovec __user *vec,
 		compat_ulong_t vlen, u32 pos_low, u32 pos_high, rwf_t flags);
 asmlinkage ssize_t compat_sys_pwritev2(compat_ulong_t fd,
-		const struct compat_iovec __user *vec,
+		const struct iovec __user *vec,
 		compat_ulong_t vlen, u32 pos_low, u32 pos_high, rwf_t flags);
 #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64V2
 asmlinkage long  compat_sys_preadv64v2(unsigned long fd,
-		const struct compat_iovec __user *vec,
+		const struct iovec __user *vec,
 		unsigned long vlen, loff_t pos, rwf_t flags);
 #endif
 
 #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64V2
 asmlinkage long compat_sys_pwritev64v2(unsigned long fd,
-		const struct compat_iovec __user *vec,
+		const struct iovec __user *vec,
 		unsigned long vlen, loff_t pos, rwf_t flags);
 #endif
 
-- 
2.28.0


  parent reply index

Thread overview: 79+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-25  4:51 let import_iovec deal with compat_iovecs as well v4 Christoph Hellwig
2020-09-25  4:51 ` [PATCH 1/9] compat.h: fix a spelling error in <linux/compat.h> Christoph Hellwig
2020-09-25  4:51 ` [PATCH 2/9] iov_iter: move rw_copy_check_uvector() into lib/iov_iter.c Christoph Hellwig
2020-10-21 16:13   ` Buggy commit tracked to: "Re: [PATCH 2/9] iov_iter: move rw_copy_check_uvector() into lib/iov_iter.c" Greg KH
2020-10-21 20:59     ` David Laight
2020-10-21 23:39     ` Al Viro
2020-10-22  8:26       ` Greg KH
2020-10-22  8:35         ` David Hildenbrand
2020-10-22  8:40           ` David Laight
2020-10-22  8:48             ` David Hildenbrand
2020-10-22  9:01               ` Greg KH
2020-10-22  9:06                 ` David Laight
2020-10-22  9:19                 ` David Hildenbrand
2020-10-22  9:25                   ` David Hildenbrand
2020-10-22  9:32                     ` David Laight
2020-10-22  9:36                       ` David Hildenbrand
2020-10-22 10:48                         ` Greg KH
2020-10-22 12:18                           ` Greg KH
2020-10-22 12:42                             ` David Hildenbrand
2020-10-22 12:57                               ` Greg KH
2020-10-22 13:50                                 ` Greg KH
     [not found]                                   ` <CAK8P3a1B7OVdyzW0-97JwzZiwp0D0fnSfyete16QTvPp_1m07A@mail.gmail.com>
2020-10-22 14:40                                     ` Greg KH
2020-10-22 16:15                                       ` David Laight
2020-10-23 12:46                                   ` David Laight
2020-10-23 13:09                                     ` David Hildenbrand
2020-10-23 14:33                                       ` David Hildenbrand
2020-10-23 14:39                                         ` David Laight
2020-10-23 14:47                                           ` 'Greg KH'
2020-10-23 16:33                                             ` David Hildenbrand
2020-11-02  9:06                                             ` David Laight
2020-11-02 13:52                                               ` 'Greg KH'
2020-11-02 18:23                                                 ` David Laight
2020-10-23 17:58                                       ` Al Viro
2020-10-23 18:27                                         ` Segher Boessenkool
2020-10-23 21:28                                           ` David Laight
2020-10-24 17:29                                             ` Segher Boessenkool
2020-10-24 21:12                                               ` David Laight
     [not found]                                     ` <CAK8P3a1n+b8hOMhNQSDzgic03dyXbmpccfTJ3C1bGKvzsgMXbg@mail.gmail.com>
2020-10-23 13:28                                       ` David Laight
2020-10-22 13:23                         ` Christoph Hellwig
2020-10-22 16:35                           ` David Laight
2020-10-22 16:40                             ` Matthew Wilcox
2020-10-22 16:50                               ` David Laight
2020-10-22 17:00                               ` Nick Desaulniers
2020-10-22 20:59                                 ` Eric Biggers
2020-10-22 21:28                                   ` Al Viro
2020-10-22 18:19                               ` Al Viro
2020-10-22 17:54                             ` Nick Desaulniers
     [not found]                               ` <CAK8P3a3LjG+ZvmQrkb9zpgov8xBkQQWrkHBPgjfYSqBKGrwT4w@mail.gmail.com>
2020-10-22 19:04                                 ` Nick Desaulniers
2020-10-22 19:24                                   ` Al Viro
2020-10-22 19:27                                     ` Al Viro
2020-10-22 20:06                                     ` Al Viro
2020-10-22 20:09                                       ` Al Viro
2020-10-22 20:11                                     ` Nick Desaulniers
2020-10-22 22:07                                     ` David Laight
2020-10-23 13:12                                     ` David Hildenbrand
2020-10-22 22:04                                   ` David Laight
2020-10-22  9:28                   ` David Laight
2020-10-22  9:02               ` David Laight
2020-09-25  4:51 ` [PATCH 3/9] iov_iter: refactor rw_copy_check_uvector and import_iovec Christoph Hellwig
2020-09-25  4:51 ` [PATCH 4/9] iov_iter: transparently handle compat iovecs in import_iovec Christoph Hellwig
2020-09-25  4:51 ` Christoph Hellwig [this message]
2020-09-25  4:51 ` [PATCH 6/9] fs: remove the compat readv/writev syscalls Christoph Hellwig
2020-09-25  4:51 ` [PATCH 7/9] fs: remove compat_sys_vmsplice Christoph Hellwig
2020-09-25  4:51 ` [PATCH 8/9] mm: remove compat_process_vm_{readv,writev} Christoph Hellwig
2020-09-25  4:51 ` [PATCH 9/9] security/keys: remove compat_keyctl_instantiate_key_iov Christoph Hellwig
2020-09-25 15:23 ` let import_iovec deal with compat_iovecs as well v4 Al Viro
  -- strict thread matches above, loose matches on Subject: below --
2020-09-23  6:05 let import_iovec deal with compat_iovecs as well v3 Christoph Hellwig
2020-09-23  6:05 ` [PATCH 5/9] fs: remove various compat readv/writev helpers Christoph Hellwig
2020-09-23 14:25   ` Al Viro
2020-09-23 14:32     ` Christoph Hellwig
2020-09-23 14:59       ` Al Viro
2020-09-23 16:38         ` Al Viro
2020-09-23 17:05           ` Al Viro
2020-09-23 17:46             ` Christoph Hellwig
2020-09-23 17:08           ` Brian Gerst
2020-09-23 18:45           ` Arnd Bergmann
2020-09-23 19:47             ` Al Viro
2020-09-23 19:52               ` Arnd Bergmann
2020-09-23 21:30             ` David Laight
2020-09-18 12:45 let import_iovec deal with compat_iovecs as well Christoph Hellwig
2020-09-18 12:45 ` [PATCH 5/9] fs: remove various compat readv/writev helpers Christoph Hellwig

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