From 411d9475cf901b5a6d2996b46cb5726184a4fa50 Mon Sep 17 00:00:00 2001
From: Dominik Brodowski <linux@dominikbrodowski.net>
Date: Sun, 11 Mar 2018 11:34:54 +0100
Subject: fs: add ksys_ftruncate() wrapper; remove in-kernel calls to
 sys_ftruncate()

Using the ksys_ftruncate() wrapper allows us to get rid of in-kernel
calls to the sys_ftruncate() syscall. The ksys_ prefix denotes that this
function is meant as a drop-in replacement for the syscall. In
particular, it uses the same calling convention as sys_ftruncate().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
---
 arch/parisc/kernel/sys_parisc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'arch/parisc')

diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c
index 378a754ca186..6d2a64859c22 100644
--- a/arch/parisc/kernel/sys_parisc.c
+++ b/arch/parisc/kernel/sys_parisc.c
@@ -298,7 +298,7 @@ asmlinkage long parisc_truncate64(const char __user * path,
 asmlinkage long parisc_ftruncate64(unsigned int fd,
 					unsigned int high, unsigned int low)
 {
-	return sys_ftruncate(fd, (long)high << 32 | low);
+	return ksys_ftruncate(fd, (long)high << 32 | low);
 }
 
 /* stubs for the benefit of the syscall_table since truncate64 and truncate 
@@ -309,7 +309,7 @@ asmlinkage long sys_truncate64(const char __user * path, unsigned long length)
 }
 asmlinkage long sys_ftruncate64(unsigned int fd, unsigned long length)
 {
-	return sys_ftruncate(fd, length);
+	return ksys_ftruncate(fd, length);
 }
 asmlinkage long sys_fcntl64(unsigned int fd, unsigned int cmd, unsigned long arg)
 {
-- 
cgit v1.2.3


From 806cbae1228cc1a19b978c4513f6851e9ab7f388 Mon Sep 17 00:00:00 2001
From: Dominik Brodowski <linux@dominikbrodowski.net>
Date: Sun, 11 Mar 2018 11:34:47 +0100
Subject: fs: add ksys_sync_file_range helper(); remove in-kernel calls to
 syscall

Using this helper allows us to avoid the in-kernel calls to the
sys_sync_file_range() syscall. The ksys_ prefix denotes that this function
is meant as a drop-in replacement for the syscall. In particular, it uses
the same calling convention as sys_sync_file_range().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
---
 arch/mips/kernel/linux32.c      |  2 +-
 arch/parisc/kernel/sys_parisc.c |  2 +-
 arch/powerpc/kernel/sys_ppc32.c |  2 +-
 arch/s390/kernel/compat_linux.c |  2 +-
 arch/sparc/kernel/sys_sparc32.c |  2 +-
 arch/x86/ia32/sys_ia32.c        |  6 +++---
 fs/sync.c                       | 12 +++++++++---
 include/linux/syscalls.h        |  2 ++
 8 files changed, 19 insertions(+), 11 deletions(-)

(limited to 'arch/parisc')

diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c
index 3c90449742a0..57b3310873f0 100644
--- a/arch/mips/kernel/linux32.c
+++ b/arch/mips/kernel/linux32.c
@@ -139,7 +139,7 @@ asmlinkage long sys32_sync_file_range(int fd, int __pad,
 	unsigned long a4, unsigned long a5,
 	int flags)
 {
-	return sys_sync_file_range(fd,
+	return ksys_sync_file_range(fd,
 			merge_64(a2, a3), merge_64(a4, a5),
 			flags);
 }
diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c
index 6d2a64859c22..ef995b5d97ef 100644
--- a/arch/parisc/kernel/sys_parisc.c
+++ b/arch/parisc/kernel/sys_parisc.c
@@ -360,7 +360,7 @@ asmlinkage long parisc_sync_file_range(int fd,
 			u32 hi_off, u32 lo_off, u32 hi_nbytes, u32 lo_nbytes,
 			unsigned int flags)
 {
-	return sys_sync_file_range(fd, (loff_t)hi_off << 32 | lo_off,
+	return ksys_sync_file_range(fd, (loff_t)hi_off << 32 | lo_off,
 			(loff_t)hi_nbytes << 32 | lo_nbytes, flags);
 }
 
diff --git a/arch/powerpc/kernel/sys_ppc32.c b/arch/powerpc/kernel/sys_ppc32.c
index e0c9b7f1bf38..664e4c5b5855 100644
--- a/arch/powerpc/kernel/sys_ppc32.c
+++ b/arch/powerpc/kernel/sys_ppc32.c
@@ -124,5 +124,5 @@ asmlinkage long compat_sys_sync_file_range2(int fd, unsigned int flags,
 	loff_t offset = ((loff_t)offset_hi << 32) | offset_lo;
 	loff_t nbytes = ((loff_t)nbytes_hi << 32) | nbytes_lo;
 
-	return sys_sync_file_range(fd, offset, nbytes, flags);
+	return ksys_sync_file_range(fd, offset, nbytes, flags);
 }
diff --git a/arch/s390/kernel/compat_linux.c b/arch/s390/kernel/compat_linux.c
index af0469f204fd..605f6f026e44 100644
--- a/arch/s390/kernel/compat_linux.c
+++ b/arch/s390/kernel/compat_linux.c
@@ -509,7 +509,7 @@ COMPAT_SYSCALL_DEFINE1(s390_fadvise64_64, struct fadvise64_64_args __user *, arg
 COMPAT_SYSCALL_DEFINE6(s390_sync_file_range, int, fd, u32, offhigh, u32, offlow,
 		       u32, nhigh, u32, nlow, unsigned int, flags)
 {
-	return sys_sync_file_range(fd, ((loff_t)offhigh << 32) + offlow,
+	return ksys_sync_file_range(fd, ((loff_t)offhigh << 32) + offlow,
 				   ((u64)nhigh << 32) + nlow, flags);
 }
 
diff --git a/arch/sparc/kernel/sys_sparc32.c b/arch/sparc/kernel/sys_sparc32.c
index d64b425fff93..af18b9ff86be 100644
--- a/arch/sparc/kernel/sys_sparc32.c
+++ b/arch/sparc/kernel/sys_sparc32.c
@@ -241,7 +241,7 @@ long compat_sys_fadvise64_64(int fd,
 
 long sys32_sync_file_range(unsigned int fd, unsigned long off_high, unsigned long off_low, unsigned long nb_high, unsigned long nb_low, unsigned int flags)
 {
-	return sys_sync_file_range(fd,
+	return ksys_sync_file_range(fd,
 				   (off_high << 32) | off_low,
 				   (nb_high << 32) | nb_low,
 				   flags);
diff --git a/arch/x86/ia32/sys_ia32.c b/arch/x86/ia32/sys_ia32.c
index 1979e5b4ad9a..0c5f8932c136 100644
--- a/arch/x86/ia32/sys_ia32.c
+++ b/arch/x86/ia32/sys_ia32.c
@@ -209,9 +209,9 @@ COMPAT_SYSCALL_DEFINE6(x86_sync_file_range, int, fd, unsigned int, off_low,
 		       unsigned int, off_hi, unsigned int, n_low,
 		       unsigned int, n_hi, int, flags)
 {
-	return sys_sync_file_range(fd,
-				   ((u64)off_hi << 32) | off_low,
-				   ((u64)n_hi << 32) | n_low, flags);
+	return ksys_sync_file_range(fd,
+				    ((u64)off_hi << 32) | off_low,
+				    ((u64)n_hi << 32) | n_low, flags);
 }
 
 COMPAT_SYSCALL_DEFINE5(x86_fadvise64, int, fd, unsigned int, offset_lo,
diff --git a/fs/sync.c b/fs/sync.c
index 602ae94bb67e..9908a114d506 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -285,8 +285,8 @@ SYSCALL_DEFINE1(fdatasync, unsigned int, fd)
  * already-instantiated disk blocks, there are no guarantees here that the data
  * will be available after a crash.
  */
-SYSCALL_DEFINE4(sync_file_range, int, fd, loff_t, offset, loff_t, nbytes,
-				unsigned int, flags)
+int ksys_sync_file_range(int fd, loff_t offset, loff_t nbytes,
+			 unsigned int flags)
 {
 	int ret;
 	struct fd f;
@@ -364,10 +364,16 @@ out:
 	return ret;
 }
 
+SYSCALL_DEFINE4(sync_file_range, int, fd, loff_t, offset, loff_t, nbytes,
+				unsigned int, flags)
+{
+	return ksys_sync_file_range(fd, offset, nbytes, flags);
+}
+
 /* It would be nice if people remember that not all the world's an i386
    when they introduce new system calls */
 SYSCALL_DEFINE4(sync_file_range2, int, fd, unsigned int, flags,
 				 loff_t, offset, loff_t, nbytes)
 {
-	return sys_sync_file_range(fd, offset, nbytes, flags);
+	return ksys_sync_file_range(fd, offset, nbytes, flags);
 }
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 4dd685ee425d..331da76f66e2 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -963,6 +963,8 @@ ssize_t ksys_read(unsigned int fd, char __user *buf, size_t count);
 void ksys_sync(void);
 int ksys_unshare(unsigned long unshare_flags);
 int ksys_setsid(void);
+int ksys_sync_file_range(int fd, loff_t offset, loff_t nbytes,
+			 unsigned int flags);
 
 /*
  * The following kernel syscall equivalents are just wrappers to fs-internal
-- 
cgit v1.2.3


From df260e21e6cd5d2dfc1fe9b6a3bbf747e72b3bed Mon Sep 17 00:00:00 2001
From: Dominik Brodowski <linux@dominikbrodowski.net>
Date: Mon, 19 Mar 2018 17:32:11 +0100
Subject: fs: add ksys_truncate() wrapper; remove in-kernel calls to
 sys_truncate()

Using the ksys_truncate() wrapper allows us to get rid of in-kernel
calls to the sys_truncate() syscall. The ksys_ prefix denotes that this
function is meant as a drop-in replacement for the syscall. In
particular, it uses the same calling convention as sys_truncate().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
---
 arch/mips/kernel/linux32.c      | 2 +-
 arch/parisc/kernel/sys_parisc.c | 6 +++---
 arch/powerpc/kernel/sys_ppc32.c | 2 +-
 arch/s390/kernel/compat_linux.c | 2 +-
 arch/sparc/kernel/sys_sparc32.c | 2 +-
 arch/x86/ia32/sys_ia32.c        | 3 ++-
 fs/open.c                       | 2 +-
 include/linux/syscalls.h        | 7 +++++++
 8 files changed, 17 insertions(+), 9 deletions(-)

(limited to 'arch/parisc')

diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c
index 57b3310873f0..58e7dd27f106 100644
--- a/arch/mips/kernel/linux32.c
+++ b/arch/mips/kernel/linux32.c
@@ -82,7 +82,7 @@ struct rlimit32 {
 SYSCALL_DEFINE4(32_truncate64, const char __user *, path,
 	unsigned long, __dummy, unsigned long, a2, unsigned long, a3)
 {
-	return sys_truncate(path, merge_64(a2, a3));
+	return ksys_truncate(path, merge_64(a2, a3));
 }
 
 SYSCALL_DEFINE4(32_ftruncate64, unsigned long, fd, unsigned long, __dummy,
diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c
index ef995b5d97ef..3377a00163c3 100644
--- a/arch/parisc/kernel/sys_parisc.c
+++ b/arch/parisc/kernel/sys_parisc.c
@@ -292,7 +292,7 @@ asmlinkage unsigned long sys_mmap(unsigned long addr, unsigned long len,
 asmlinkage long parisc_truncate64(const char __user * path,
 					unsigned int high, unsigned int low)
 {
-	return sys_truncate(path, (long)high << 32 | low);
+	return ksys_truncate(path, (long)high << 32 | low);
 }
 
 asmlinkage long parisc_ftruncate64(unsigned int fd,
@@ -305,7 +305,7 @@ asmlinkage long parisc_ftruncate64(unsigned int fd,
  * are identical on LP64 */
 asmlinkage long sys_truncate64(const char __user * path, unsigned long length)
 {
-	return sys_truncate(path, length);
+	return ksys_truncate(path, length);
 }
 asmlinkage long sys_ftruncate64(unsigned int fd, unsigned long length)
 {
@@ -320,7 +320,7 @@ asmlinkage long sys_fcntl64(unsigned int fd, unsigned int cmd, unsigned long arg
 asmlinkage long parisc_truncate64(const char __user * path,
 					unsigned int high, unsigned int low)
 {
-	return sys_truncate64(path, (loff_t)high << 32 | low);
+	return ksys_truncate(path, (loff_t)high << 32 | low);
 }
 
 asmlinkage long parisc_ftruncate64(unsigned int fd,
diff --git a/arch/powerpc/kernel/sys_ppc32.c b/arch/powerpc/kernel/sys_ppc32.c
index 664e4c5b5855..a0a251d7c9c5 100644
--- a/arch/powerpc/kernel/sys_ppc32.c
+++ b/arch/powerpc/kernel/sys_ppc32.c
@@ -94,7 +94,7 @@ compat_ssize_t compat_sys_readahead(int fd, u32 r4, u32 offhi, u32 offlo, u32 co
 asmlinkage int compat_sys_truncate64(const char __user * path, u32 reg4,
 				unsigned long high, unsigned long low)
 {
-	return sys_truncate(path, (high << 32) | low);
+	return ksys_truncate(path, (high << 32) | low);
 }
 
 asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offhi, u32 offlo,
diff --git a/arch/s390/kernel/compat_linux.c b/arch/s390/kernel/compat_linux.c
index 605f6f026e44..e4092ec17ea5 100644
--- a/arch/s390/kernel/compat_linux.c
+++ b/arch/s390/kernel/compat_linux.c
@@ -302,7 +302,7 @@ COMPAT_SYSCALL_DEFINE5(s390_ipc, uint, call, int, first, compat_ulong_t, second,
 
 COMPAT_SYSCALL_DEFINE3(s390_truncate64, const char __user *, path, u32, high, u32, low)
 {
-	return sys_truncate(path, (unsigned long)high << 32 | low);
+	return ksys_truncate(path, (unsigned long)high << 32 | low);
 }
 
 COMPAT_SYSCALL_DEFINE3(s390_ftruncate64, unsigned int, fd, u32, high, u32, low)
diff --git a/arch/sparc/kernel/sys_sparc32.c b/arch/sparc/kernel/sys_sparc32.c
index af18b9ff86be..aab2428b17b5 100644
--- a/arch/sparc/kernel/sys_sparc32.c
+++ b/arch/sparc/kernel/sys_sparc32.c
@@ -57,7 +57,7 @@ asmlinkage long sys32_truncate64(const char __user * path, unsigned long high, u
 	if ((int)high < 0)
 		return -EINVAL;
 	else
-		return sys_truncate(path, (high << 32) | low);
+		return ksys_truncate(path, (high << 32) | low);
 }
 
 asmlinkage long sys32_ftruncate64(unsigned int fd, unsigned long high, unsigned long low)
diff --git a/arch/x86/ia32/sys_ia32.c b/arch/x86/ia32/sys_ia32.c
index 0c5f8932c136..90e7a2b3dc5b 100644
--- a/arch/x86/ia32/sys_ia32.c
+++ b/arch/x86/ia32/sys_ia32.c
@@ -55,7 +55,8 @@
 COMPAT_SYSCALL_DEFINE3(x86_truncate64, const char __user *, filename,
 		       unsigned long, offset_low, unsigned long, offset_high)
 {
-       return sys_truncate(filename, ((loff_t) offset_high << 32) | offset_low);
+	return ksys_truncate(filename,
+			    ((loff_t) offset_high << 32) | offset_low);
 }
 
 COMPAT_SYSCALL_DEFINE3(x86_ftruncate64, unsigned int, fd,
diff --git a/fs/open.c b/fs/open.c
index 8a42a2961130..2e816fc7bd56 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -128,7 +128,7 @@ out:
 }
 EXPORT_SYMBOL_GPL(vfs_truncate);
 
-static long do_sys_truncate(const char __user *pathname, loff_t length)
+long do_sys_truncate(const char __user *pathname, loff_t length)
 {
 	unsigned int lookup_flags = LOOKUP_FOLLOW;
 	struct path path;
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 331da76f66e2..78b79e3a1279 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -1078,4 +1078,11 @@ static inline long ksys_open(const char __user *filename, int flags,
 	return do_sys_open(AT_FDCWD, filename, flags, mode);
 }
 
+extern long do_sys_truncate(const char __user *pathname, loff_t length);
+
+static inline long ksys_truncate(const char __user *pathname, loff_t length)
+{
+	return do_sys_truncate(pathname, length);
+}
+
 #endif
-- 
cgit v1.2.3


From 36028d5dd71175c332ab634e089e16dbdfe3812b Mon Sep 17 00:00:00 2001
From: Dominik Brodowski <linux@dominikbrodowski.net>
Date: Mon, 19 Mar 2018 17:38:31 +0100
Subject: fs: add ksys_p{read,write}64() helpers; remove in-kernel calls to
 syscalls

Using the ksys_p{read,write}64() wrappers allows us to get rid of
in-kernel calls to the sys_pread64() and sys_pwrite64() syscalls.
The ksys_ prefix denotes that this function is meant as a drop-in
replacement for the syscall. In particular, it uses the same calling
convention as sys_p{read,write}64().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
---
 arch/mips/kernel/linux32.c      |  4 ++--
 arch/parisc/kernel/sys_parisc.c |  4 ++--
 arch/powerpc/kernel/sys_ppc32.c |  4 ++--
 arch/s390/kernel/compat_linux.c |  4 ++--
 arch/sh/kernel/sys_sh32.c       |  4 ++--
 arch/sparc/kernel/sys_sparc32.c |  4 ++--
 arch/x86/ia32/sys_ia32.c        |  8 ++++----
 fs/read_write.c                 | 20 ++++++++++++++++----
 include/linux/syscalls.h        |  4 ++++
 9 files changed, 36 insertions(+), 20 deletions(-)

(limited to 'arch/parisc')

diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c
index 58e7dd27f106..91e85e2f8aa5 100644
--- a/arch/mips/kernel/linux32.c
+++ b/arch/mips/kernel/linux32.c
@@ -105,13 +105,13 @@ SYSCALL_DEFINE5(32_llseek, unsigned int, fd, unsigned int, offset_high,
 SYSCALL_DEFINE6(32_pread, unsigned long, fd, char __user *, buf, size_t, count,
 	unsigned long, unused, unsigned long, a4, unsigned long, a5)
 {
-	return sys_pread64(fd, buf, count, merge_64(a4, a5));
+	return ksys_pread64(fd, buf, count, merge_64(a4, a5));
 }
 
 SYSCALL_DEFINE6(32_pwrite, unsigned int, fd, const char __user *, buf,
 	size_t, count, u32, unused, u64, a4, u64, a5)
 {
-	return sys_pwrite64(fd, buf, count, merge_64(a4, a5));
+	return ksys_pwrite64(fd, buf, count, merge_64(a4, a5));
 }
 
 SYSCALL_DEFINE1(32_personality, unsigned long, personality)
diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c
index 3377a00163c3..4f47e8379854 100644
--- a/arch/parisc/kernel/sys_parisc.c
+++ b/arch/parisc/kernel/sys_parisc.c
@@ -333,13 +333,13 @@ asmlinkage long parisc_ftruncate64(unsigned int fd,
 asmlinkage ssize_t parisc_pread64(unsigned int fd, char __user *buf, size_t count,
 					unsigned int high, unsigned int low)
 {
-	return sys_pread64(fd, buf, count, (loff_t)high << 32 | low);
+	return ksys_pread64(fd, buf, count, (loff_t)high << 32 | low);
 }
 
 asmlinkage ssize_t parisc_pwrite64(unsigned int fd, const char __user *buf,
 			size_t count, unsigned int high, unsigned int low)
 {
-	return sys_pwrite64(fd, buf, count, (loff_t)high << 32 | low);
+	return ksys_pwrite64(fd, buf, count, (loff_t)high << 32 | low);
 }
 
 asmlinkage ssize_t parisc_readahead(int fd, unsigned int high, unsigned int low,
diff --git a/arch/powerpc/kernel/sys_ppc32.c b/arch/powerpc/kernel/sys_ppc32.c
index a0a251d7c9c5..36a651e6e033 100644
--- a/arch/powerpc/kernel/sys_ppc32.c
+++ b/arch/powerpc/kernel/sys_ppc32.c
@@ -77,13 +77,13 @@ unsigned long compat_sys_mmap2(unsigned long addr, size_t len,
 compat_ssize_t compat_sys_pread64(unsigned int fd, char __user *ubuf, compat_size_t count,
 			     u32 reg6, u32 poshi, u32 poslo)
 {
-	return sys_pread64(fd, ubuf, count, ((loff_t)poshi << 32) | poslo);
+	return ksys_pread64(fd, ubuf, count, ((loff_t)poshi << 32) | poslo);
 }
 
 compat_ssize_t compat_sys_pwrite64(unsigned int fd, const char __user *ubuf, compat_size_t count,
 			      u32 reg6, u32 poshi, u32 poslo)
 {
-	return sys_pwrite64(fd, ubuf, count, ((loff_t)poshi << 32) | poslo);
+	return ksys_pwrite64(fd, ubuf, count, ((loff_t)poshi << 32) | poslo);
 }
 
 compat_ssize_t compat_sys_readahead(int fd, u32 r4, u32 offhi, u32 offlo, u32 count)
diff --git a/arch/s390/kernel/compat_linux.c b/arch/s390/kernel/compat_linux.c
index e4092ec17ea5..71e2c5bc4926 100644
--- a/arch/s390/kernel/compat_linux.c
+++ b/arch/s390/kernel/compat_linux.c
@@ -315,7 +315,7 @@ COMPAT_SYSCALL_DEFINE5(s390_pread64, unsigned int, fd, char __user *, ubuf,
 {
 	if ((compat_ssize_t) count < 0)
 		return -EINVAL;
-	return sys_pread64(fd, ubuf, count, (unsigned long)high << 32 | low);
+	return ksys_pread64(fd, ubuf, count, (unsigned long)high << 32 | low);
 }
 
 COMPAT_SYSCALL_DEFINE5(s390_pwrite64, unsigned int, fd, const char __user *, ubuf,
@@ -323,7 +323,7 @@ COMPAT_SYSCALL_DEFINE5(s390_pwrite64, unsigned int, fd, const char __user *, ubu
 {
 	if ((compat_ssize_t) count < 0)
 		return -EINVAL;
-	return sys_pwrite64(fd, ubuf, count, (unsigned long)high << 32 | low);
+	return ksys_pwrite64(fd, ubuf, count, (unsigned long)high << 32 | low);
 }
 
 COMPAT_SYSCALL_DEFINE4(s390_readahead, int, fd, u32, high, u32, low, s32, count)
diff --git a/arch/sh/kernel/sys_sh32.c b/arch/sh/kernel/sys_sh32.c
index f8dc8bfd4606..c37ee3d0c803 100644
--- a/arch/sh/kernel/sys_sh32.c
+++ b/arch/sh/kernel/sys_sh32.c
@@ -39,13 +39,13 @@ asmlinkage int sys_sh_pipe(void)
 asmlinkage ssize_t sys_pread_wrapper(unsigned int fd, char __user *buf,
 			     size_t count, long dummy, loff_t pos)
 {
-	return sys_pread64(fd, buf, count, pos);
+	return ksys_pread64(fd, buf, count, pos);
 }
 
 asmlinkage ssize_t sys_pwrite_wrapper(unsigned int fd, const char __user *buf,
 			      size_t count, long dummy, loff_t pos)
 {
-	return sys_pwrite64(fd, buf, count, pos);
+	return ksys_pwrite64(fd, buf, count, pos);
 }
 
 asmlinkage int sys_fadvise64_64_wrapper(int fd, u32 offset0, u32 offset1,
diff --git a/arch/sparc/kernel/sys_sparc32.c b/arch/sparc/kernel/sys_sparc32.c
index aab2428b17b5..40c0d2e1db1d 100644
--- a/arch/sparc/kernel/sys_sparc32.c
+++ b/arch/sparc/kernel/sys_sparc32.c
@@ -200,7 +200,7 @@ asmlinkage compat_ssize_t sys32_pread64(unsigned int fd,
 					unsigned long poshi,
 					unsigned long poslo)
 {
-	return sys_pread64(fd, ubuf, count, (poshi << 32) | poslo);
+	return ksys_pread64(fd, ubuf, count, (poshi << 32) | poslo);
 }
 
 asmlinkage compat_ssize_t sys32_pwrite64(unsigned int fd,
@@ -209,7 +209,7 @@ asmlinkage compat_ssize_t sys32_pwrite64(unsigned int fd,
 					 unsigned long poshi,
 					 unsigned long poslo)
 {
-	return sys_pwrite64(fd, ubuf, count, (poshi << 32) | poslo);
+	return ksys_pwrite64(fd, ubuf, count, (poshi << 32) | poslo);
 }
 
 asmlinkage long compat_sys_readahead(int fd,
diff --git a/arch/x86/ia32/sys_ia32.c b/arch/x86/ia32/sys_ia32.c
index 90e7a2b3dc5b..c08c25f73d79 100644
--- a/arch/x86/ia32/sys_ia32.c
+++ b/arch/x86/ia32/sys_ia32.c
@@ -174,15 +174,15 @@ COMPAT_SYSCALL_DEFINE1(x86_mmap, struct mmap_arg_struct32 __user *, arg)
 COMPAT_SYSCALL_DEFINE5(x86_pread, unsigned int, fd, char __user *, ubuf,
 		       u32, count, u32, poslo, u32, poshi)
 {
-	return sys_pread64(fd, ubuf, count,
-			 ((loff_t)AA(poshi) << 32) | AA(poslo));
+	return ksys_pread64(fd, ubuf, count,
+			    ((loff_t)AA(poshi) << 32) | AA(poslo));
 }
 
 COMPAT_SYSCALL_DEFINE5(x86_pwrite, unsigned int, fd, const char __user *, ubuf,
 		       u32, count, u32, poslo, u32, poshi)
 {
-	return sys_pwrite64(fd, ubuf, count,
-			  ((loff_t)AA(poshi) << 32) | AA(poslo));
+	return ksys_pwrite64(fd, ubuf, count,
+			     ((loff_t)AA(poshi) << 32) | AA(poslo));
 }
 
 
diff --git a/fs/read_write.c b/fs/read_write.c
index fc441e1ac683..c4eabbfc90df 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -610,8 +610,8 @@ SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf,
 	return ksys_write(fd, buf, count);
 }
 
-SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf,
-			size_t, count, loff_t, pos)
+ssize_t ksys_pread64(unsigned int fd, char __user *buf, size_t count,
+		     loff_t pos)
 {
 	struct fd f;
 	ssize_t ret = -EBADF;
@@ -630,8 +630,14 @@ SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf,
 	return ret;
 }
 
-SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf,
-			 size_t, count, loff_t, pos)
+SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf,
+			size_t, count, loff_t, pos)
+{
+	return ksys_pread64(fd, buf, count, pos);
+}
+
+ssize_t ksys_pwrite64(unsigned int fd, const char __user *buf,
+		      size_t count, loff_t pos)
 {
 	struct fd f;
 	ssize_t ret = -EBADF;
@@ -650,6 +656,12 @@ SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf,
 	return ret;
 }
 
+SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf,
+			 size_t, count, loff_t, pos)
+{
+	return ksys_pwrite64(fd, buf, count, pos);
+}
+
 static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter,
 		loff_t *ppos, int type, rwf_t flags)
 {
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 78b79e3a1279..a30e4c2d0c27 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -965,6 +965,10 @@ int ksys_unshare(unsigned long unshare_flags);
 int ksys_setsid(void);
 int ksys_sync_file_range(int fd, loff_t offset, loff_t nbytes,
 			 unsigned int flags);
+ssize_t ksys_pread64(unsigned int fd, char __user *buf, size_t count,
+		     loff_t pos);
+ssize_t ksys_pwrite64(unsigned int fd, const char __user *buf,
+		      size_t count, loff_t pos);
 
 /*
  * The following kernel syscall equivalents are just wrappers to fs-internal
-- 
cgit v1.2.3


From edf292c76b884a499cc60ad5cdada2663cc39a2f Mon Sep 17 00:00:00 2001
From: Dominik Brodowski <linux@dominikbrodowski.net>
Date: Mon, 19 Mar 2018 17:46:32 +0100
Subject: fs: add ksys_fallocate() wrapper; remove in-kernel calls to
 sys_fallocate()

Using the ksys_fallocate() wrapper allows us to get rid of in-kernel
calls to the sys_fallocate() syscall. The ksys_ prefix denotes that this
function is meant as a drop-in replacement for the syscall. In
particular, it uses the same calling convention as sys_fallocate().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
---
 arch/mips/kernel/linux32.c      | 4 ++--
 arch/parisc/kernel/sys_parisc.c | 4 ++--
 arch/powerpc/kernel/sys_ppc32.c | 2 +-
 arch/s390/kernel/compat_linux.c | 4 ++--
 arch/sparc/kernel/sys_sparc32.c | 4 ++--
 arch/x86/ia32/sys_ia32.c        | 4 ++--
 fs/open.c                       | 7 ++++++-
 include/linux/syscalls.h        | 1 +
 8 files changed, 18 insertions(+), 12 deletions(-)

(limited to 'arch/parisc')

diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c
index 91e85e2f8aa5..0779d474c8ad 100644
--- a/arch/mips/kernel/linux32.c
+++ b/arch/mips/kernel/linux32.c
@@ -157,6 +157,6 @@ asmlinkage long sys32_fadvise64_64(int fd, int __pad,
 asmlinkage long sys32_fallocate(int fd, int mode, unsigned offset_a2,
 	unsigned offset_a3, unsigned len_a4, unsigned len_a5)
 {
-	return sys_fallocate(fd, mode, merge_64(offset_a2, offset_a3),
-			     merge_64(len_a4, len_a5));
+	return ksys_fallocate(fd, mode, merge_64(offset_a2, offset_a3),
+			      merge_64(len_a4, len_a5));
 }
diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c
index 4f47e8379854..588fab336ddd 100644
--- a/arch/parisc/kernel/sys_parisc.c
+++ b/arch/parisc/kernel/sys_parisc.c
@@ -367,8 +367,8 @@ asmlinkage long parisc_sync_file_range(int fd,
 asmlinkage long parisc_fallocate(int fd, int mode, u32 offhi, u32 offlo,
 				u32 lenhi, u32 lenlo)
 {
-        return sys_fallocate(fd, mode, ((u64)offhi << 32) | offlo,
-                             ((u64)lenhi << 32) | lenlo);
+	return ksys_fallocate(fd, mode, ((u64)offhi << 32) | offlo,
+			      ((u64)lenhi << 32) | lenlo);
 }
 
 long parisc_personality(unsigned long personality)
diff --git a/arch/powerpc/kernel/sys_ppc32.c b/arch/powerpc/kernel/sys_ppc32.c
index 36a651e6e033..68f11e1065f8 100644
--- a/arch/powerpc/kernel/sys_ppc32.c
+++ b/arch/powerpc/kernel/sys_ppc32.c
@@ -100,7 +100,7 @@ asmlinkage int compat_sys_truncate64(const char __user * path, u32 reg4,
 asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offhi, u32 offlo,
 				     u32 lenhi, u32 lenlo)
 {
-	return sys_fallocate(fd, mode, ((loff_t)offhi << 32) | offlo,
+	return ksys_fallocate(fd, mode, ((loff_t)offhi << 32) | offlo,
 			     ((loff_t)lenhi << 32) | lenlo);
 }
 
diff --git a/arch/s390/kernel/compat_linux.c b/arch/s390/kernel/compat_linux.c
index 71e2c5bc4926..039858f9f128 100644
--- a/arch/s390/kernel/compat_linux.c
+++ b/arch/s390/kernel/compat_linux.c
@@ -516,6 +516,6 @@ COMPAT_SYSCALL_DEFINE6(s390_sync_file_range, int, fd, u32, offhigh, u32, offlow,
 COMPAT_SYSCALL_DEFINE6(s390_fallocate, int, fd, int, mode, u32, offhigh, u32, offlow,
 		       u32, lenhigh, u32, lenlow)
 {
-	return sys_fallocate(fd, mode, ((loff_t)offhigh << 32) + offlow,
-			     ((u64)lenhigh << 32) + lenlow);
+	return ksys_fallocate(fd, mode, ((loff_t)offhigh << 32) + offlow,
+			      ((u64)lenhigh << 32) + lenlow);
 }
diff --git a/arch/sparc/kernel/sys_sparc32.c b/arch/sparc/kernel/sys_sparc32.c
index 40c0d2e1db1d..4ba62d676632 100644
--- a/arch/sparc/kernel/sys_sparc32.c
+++ b/arch/sparc/kernel/sys_sparc32.c
@@ -250,6 +250,6 @@ long sys32_sync_file_range(unsigned int fd, unsigned long off_high, unsigned lon
 asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offhi, u32 offlo,
 				     u32 lenhi, u32 lenlo)
 {
-	return sys_fallocate(fd, mode, ((loff_t)offhi << 32) | offlo,
-			     ((loff_t)lenhi << 32) | lenlo);
+	return ksys_fallocate(fd, mode, ((loff_t)offhi << 32) | offlo,
+			      ((loff_t)lenhi << 32) | lenlo);
 }
diff --git a/arch/x86/ia32/sys_ia32.c b/arch/x86/ia32/sys_ia32.c
index c08c25f73d79..df2acb13623f 100644
--- a/arch/x86/ia32/sys_ia32.c
+++ b/arch/x86/ia32/sys_ia32.c
@@ -226,8 +226,8 @@ COMPAT_SYSCALL_DEFINE6(x86_fallocate, int, fd, int, mode,
 		       unsigned int, offset_lo, unsigned int, offset_hi,
 		       unsigned int, len_lo, unsigned int, len_hi)
 {
-	return sys_fallocate(fd, mode, ((u64)offset_hi << 32) | offset_lo,
-			     ((u64)len_hi << 32) | len_lo);
+	return ksys_fallocate(fd, mode, ((u64)offset_hi << 32) | offset_lo,
+			      ((u64)len_hi << 32) | len_lo);
 }
 
 /*
diff --git a/fs/open.c b/fs/open.c
index 2e816fc7bd56..d0e955b558ad 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -333,7 +333,7 @@ int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
 }
 EXPORT_SYMBOL_GPL(vfs_fallocate);
 
-SYSCALL_DEFINE4(fallocate, int, fd, int, mode, loff_t, offset, loff_t, len)
+int ksys_fallocate(int fd, int mode, loff_t offset, loff_t len)
 {
 	struct fd f = fdget(fd);
 	int error = -EBADF;
@@ -345,6 +345,11 @@ SYSCALL_DEFINE4(fallocate, int, fd, int, mode, loff_t, offset, loff_t, len)
 	return error;
 }
 
+SYSCALL_DEFINE4(fallocate, int, fd, int, mode, loff_t, offset, loff_t, len)
+{
+	return ksys_fallocate(fd, mode, offset, len);
+}
+
 /*
  * access() needs to use the real uid/gid, not the effective uid/gid.
  * We do this by temporarily clearing all FS-related capabilities and
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index a30e4c2d0c27..613b8127834d 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -969,6 +969,7 @@ ssize_t ksys_pread64(unsigned int fd, char __user *buf, size_t count,
 		     loff_t pos);
 ssize_t ksys_pwrite64(unsigned int fd, const char __user *buf,
 		      size_t count, loff_t pos);
+int ksys_fallocate(int fd, int mode, loff_t offset, loff_t len);
 
 /*
  * The following kernel syscall equivalents are just wrappers to fs-internal
-- 
cgit v1.2.3


From 9d5b7c956b09daab955fb2a42447d5d89ff15093 Mon Sep 17 00:00:00 2001
From: Dominik Brodowski <linux@dominikbrodowski.net>
Date: Sun, 11 Mar 2018 11:34:45 +0100
Subject: mm: add ksys_fadvise64_64() helper; remove in-kernel call to
 sys_fadvise64_64()

Using the ksys_fadvise64_64() helper allows us to avoid the in-kernel
calls to the sys_fadvise64_64() syscall. The ksys_ prefix denotes that
this function is meant as a drop-in replacement for the syscall. In
particular, it uses the same calling convention as ksys_fadvise64_64().

Some compat stubs called sys_fadvise64(), which then just passed through
the arguments to sys_fadvise64_64(). Get rid of this indirection, and call
ksys_fadvise64_64() directly.

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
---
 arch/arm/kernel/sys_arm.c       |  2 +-
 arch/mips/kernel/linux32.c      |  2 +-
 arch/parisc/kernel/sys_parisc.c |  2 +-
 arch/powerpc/kernel/sys_ppc32.c |  4 ++--
 arch/powerpc/kernel/syscalls.c  |  4 ++--
 arch/s390/kernel/compat_linux.c |  5 +++--
 arch/sh/kernel/sys_sh32.c       |  8 ++++----
 arch/sparc/kernel/sys_sparc32.c | 10 +++++-----
 arch/x86/ia32/sys_ia32.c        | 12 ++++++------
 arch/xtensa/kernel/syscall.c    |  2 +-
 include/linux/syscalls.h        |  9 +++++++++
 mm/fadvise.c                    | 10 ++++++++--
 12 files changed, 43 insertions(+), 27 deletions(-)

(limited to 'arch/parisc')

diff --git a/arch/arm/kernel/sys_arm.c b/arch/arm/kernel/sys_arm.c
index 3151f5623d0e..bdf7514204ab 100644
--- a/arch/arm/kernel/sys_arm.c
+++ b/arch/arm/kernel/sys_arm.c
@@ -35,5 +35,5 @@
 asmlinkage long sys_arm_fadvise64_64(int fd, int advice,
 				     loff_t offset, loff_t len)
 {
-	return sys_fadvise64_64(fd, offset, len, advice);
+	return ksys_fadvise64_64(fd, offset, len, advice);
 }
diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c
index 0779d474c8ad..1c5785e72db4 100644
--- a/arch/mips/kernel/linux32.c
+++ b/arch/mips/kernel/linux32.c
@@ -149,7 +149,7 @@ asmlinkage long sys32_fadvise64_64(int fd, int __pad,
 	unsigned long a4, unsigned long a5,
 	int flags)
 {
-	return sys_fadvise64_64(fd,
+	return ksys_fadvise64_64(fd,
 			merge_64(a2, a3), merge_64(a4, a5),
 			flags);
 }
diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c
index 588fab336ddd..f36ab1f09595 100644
--- a/arch/parisc/kernel/sys_parisc.c
+++ b/arch/parisc/kernel/sys_parisc.c
@@ -352,7 +352,7 @@ asmlinkage long parisc_fadvise64_64(int fd,
 			unsigned int high_off, unsigned int low_off,
 			unsigned int high_len, unsigned int low_len, int advice)
 {
-	return sys_fadvise64_64(fd, (loff_t)high_off << 32 | low_off,
+	return ksys_fadvise64_64(fd, (loff_t)high_off << 32 | low_off,
 			(loff_t)high_len << 32 | low_len, advice);
 }
 
diff --git a/arch/powerpc/kernel/sys_ppc32.c b/arch/powerpc/kernel/sys_ppc32.c
index 68f11e1065f8..0b95fa13307f 100644
--- a/arch/powerpc/kernel/sys_ppc32.c
+++ b/arch/powerpc/kernel/sys_ppc32.c
@@ -113,8 +113,8 @@ asmlinkage int compat_sys_ftruncate64(unsigned int fd, u32 reg4, unsigned long h
 long ppc32_fadvise64(int fd, u32 unused, u32 offset_high, u32 offset_low,
 		     size_t len, int advice)
 {
-	return sys_fadvise64(fd, (u64)offset_high << 32 | offset_low, len,
-			     advice);
+	return ksys_fadvise64_64(fd, (u64)offset_high << 32 | offset_low, len,
+				 advice);
 }
 
 asmlinkage long compat_sys_sync_file_range2(int fd, unsigned int flags,
diff --git a/arch/powerpc/kernel/syscalls.c b/arch/powerpc/kernel/syscalls.c
index a877bf8269fe..ecb981eea74b 100644
--- a/arch/powerpc/kernel/syscalls.c
+++ b/arch/powerpc/kernel/syscalls.c
@@ -119,8 +119,8 @@ long ppc64_personality(unsigned long personality)
 long ppc_fadvise64_64(int fd, int advice, u32 offset_high, u32 offset_low,
 		      u32 len_high, u32 len_low)
 {
-	return sys_fadvise64(fd, (u64)offset_high << 32 | offset_low,
-			     (u64)len_high << 32 | len_low, advice);
+	return ksys_fadvise64_64(fd, (u64)offset_high << 32 | offset_low,
+				 (u64)len_high << 32 | len_low, advice);
 }
 
 long sys_switch_endian(void)
diff --git a/arch/s390/kernel/compat_linux.c b/arch/s390/kernel/compat_linux.c
index 039858f9f128..9bb897e443a6 100644
--- a/arch/s390/kernel/compat_linux.c
+++ b/arch/s390/kernel/compat_linux.c
@@ -483,7 +483,8 @@ COMPAT_SYSCALL_DEFINE5(s390_fadvise64, int, fd, u32, high, u32, low, compat_size
 		advise = POSIX_FADV_DONTNEED;
 	else if (advise == 5)
 		advise = POSIX_FADV_NOREUSE;
-	return sys_fadvise64(fd, (unsigned long)high << 32 | low, len, advise);
+	return ksys_fadvise64_64(fd, (unsigned long)high << 32 | low, len,
+				 advise);
 }
 
 struct fadvise64_64_args {
@@ -503,7 +504,7 @@ COMPAT_SYSCALL_DEFINE1(s390_fadvise64_64, struct fadvise64_64_args __user *, arg
 		a.advice = POSIX_FADV_DONTNEED;
 	else if (a.advice == 5)
 		a.advice = POSIX_FADV_NOREUSE;
-	return sys_fadvise64_64(a.fd, a.offset, a.len, a.advice);
+	return ksys_fadvise64_64(a.fd, a.offset, a.len, a.advice);
 }
 
 COMPAT_SYSCALL_DEFINE6(s390_sync_file_range, int, fd, u32, offhigh, u32, offlow,
diff --git a/arch/sh/kernel/sys_sh32.c b/arch/sh/kernel/sys_sh32.c
index c37ee3d0c803..9dca568509a5 100644
--- a/arch/sh/kernel/sys_sh32.c
+++ b/arch/sh/kernel/sys_sh32.c
@@ -52,10 +52,10 @@ asmlinkage int sys_fadvise64_64_wrapper(int fd, u32 offset0, u32 offset1,
 				u32 len0, u32 len1, int advice)
 {
 #ifdef  __LITTLE_ENDIAN__
-	return sys_fadvise64_64(fd, (u64)offset1 << 32 | offset0,
-				(u64)len1 << 32 | len0,	advice);
+	return ksys_fadvise64_64(fd, (u64)offset1 << 32 | offset0,
+				 (u64)len1 << 32 | len0, advice);
 #else
-	return sys_fadvise64_64(fd, (u64)offset0 << 32 | offset1,
-				(u64)len0 << 32 | len1,	advice);
+	return ksys_fadvise64_64(fd, (u64)offset0 << 32 | offset1,
+				 (u64)len0 << 32 | len1, advice);
 #endif
 }
diff --git a/arch/sparc/kernel/sys_sparc32.c b/arch/sparc/kernel/sys_sparc32.c
index 4ba62d676632..4da66aed50b4 100644
--- a/arch/sparc/kernel/sys_sparc32.c
+++ b/arch/sparc/kernel/sys_sparc32.c
@@ -225,7 +225,7 @@ long compat_sys_fadvise64(int fd,
 			  unsigned long offlo,
 			  compat_size_t len, int advice)
 {
-	return sys_fadvise64_64(fd, (offhi << 32) | offlo, len, advice);
+	return ksys_fadvise64_64(fd, (offhi << 32) | offlo, len, advice);
 }
 
 long compat_sys_fadvise64_64(int fd,
@@ -233,10 +233,10 @@ long compat_sys_fadvise64_64(int fd,
 			     unsigned long lenhi, unsigned long lenlo,
 			     int advice)
 {
-	return sys_fadvise64_64(fd,
-				(offhi << 32) | offlo,
-				(lenhi << 32) | lenlo,
-				advice);
+	return ksys_fadvise64_64(fd,
+				 (offhi << 32) | offlo,
+				 (lenhi << 32) | lenlo,
+				 advice);
 }
 
 long sys32_sync_file_range(unsigned int fd, unsigned long off_high, unsigned long off_low, unsigned long nb_high, unsigned long nb_low, unsigned int flags)
diff --git a/arch/x86/ia32/sys_ia32.c b/arch/x86/ia32/sys_ia32.c
index df2acb13623f..401bd8ec9cf0 100644
--- a/arch/x86/ia32/sys_ia32.c
+++ b/arch/x86/ia32/sys_ia32.c
@@ -194,10 +194,10 @@ COMPAT_SYSCALL_DEFINE6(x86_fadvise64_64, int, fd, __u32, offset_low,
 		       __u32, offset_high, __u32, len_low, __u32, len_high,
 		       int, advice)
 {
-	return sys_fadvise64_64(fd,
-			       (((u64)offset_high)<<32) | offset_low,
-			       (((u64)len_high)<<32) | len_low,
-				advice);
+	return ksys_fadvise64_64(fd,
+				 (((u64)offset_high)<<32) | offset_low,
+				 (((u64)len_high)<<32) | len_low,
+				 advice);
 }
 
 COMPAT_SYSCALL_DEFINE4(x86_readahead, int, fd, unsigned int, off_lo,
@@ -218,8 +218,8 @@ COMPAT_SYSCALL_DEFINE6(x86_sync_file_range, int, fd, unsigned int, off_low,
 COMPAT_SYSCALL_DEFINE5(x86_fadvise64, int, fd, unsigned int, offset_lo,
 		       unsigned int, offset_hi, size_t, len, int, advice)
 {
-	return sys_fadvise64_64(fd, ((u64)offset_hi << 32) | offset_lo,
-				len, advice);
+	return ksys_fadvise64_64(fd, ((u64)offset_hi << 32) | offset_lo,
+				 len, advice);
 }
 
 COMPAT_SYSCALL_DEFINE6(x86_fallocate, int, fd, int, mode,
diff --git a/arch/xtensa/kernel/syscall.c b/arch/xtensa/kernel/syscall.c
index 74afbf02d07e..8201748da05b 100644
--- a/arch/xtensa/kernel/syscall.c
+++ b/arch/xtensa/kernel/syscall.c
@@ -55,7 +55,7 @@ asmlinkage long xtensa_shmat(int shmid, char __user *shmaddr, int shmflg)
 asmlinkage long xtensa_fadvise64_64(int fd, int advice,
 		unsigned long long offset, unsigned long long len)
 {
-	return sys_fadvise64_64(fd, offset, len, advice);
+	return ksys_fadvise64_64(fd, offset, len, advice);
 }
 
 #ifdef CONFIG_MMU
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 613b8127834d..466d408deefd 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -970,6 +970,15 @@ ssize_t ksys_pread64(unsigned int fd, char __user *buf, size_t count,
 ssize_t ksys_pwrite64(unsigned int fd, const char __user *buf,
 		      size_t count, loff_t pos);
 int ksys_fallocate(int fd, int mode, loff_t offset, loff_t len);
+#ifdef CONFIG_ADVISE_SYSCALLS
+int ksys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice);
+#else
+static inline int ksys_fadvise64_64(int fd, loff_t offset, loff_t len,
+				    int advice)
+{
+	return -EINVAL;
+}
+#endif
 
 /*
  * The following kernel syscall equivalents are just wrappers to fs-internal
diff --git a/mm/fadvise.c b/mm/fadvise.c
index 767887f5f3bf..afa41491d324 100644
--- a/mm/fadvise.c
+++ b/mm/fadvise.c
@@ -26,7 +26,8 @@
  * POSIX_FADV_WILLNEED could set PG_Referenced, and POSIX_FADV_NOREUSE could
  * deactivate the pages and clear PG_Referenced.
  */
-SYSCALL_DEFINE4(fadvise64_64, int, fd, loff_t, offset, loff_t, len, int, advice)
+
+int ksys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice)
 {
 	struct fd f = fdget(fd);
 	struct inode *inode;
@@ -185,11 +186,16 @@ out:
 	return ret;
 }
 
+SYSCALL_DEFINE4(fadvise64_64, int, fd, loff_t, offset, loff_t, len, int, advice)
+{
+	return ksys_fadvise64_64(fd, offset, len, advice);
+}
+
 #ifdef __ARCH_WANT_SYS_FADVISE64
 
 SYSCALL_DEFINE4(fadvise64, int, fd, loff_t, offset, size_t, len, int, advice)
 {
-	return sys_fadvise64_64(fd, offset, len, advice);
+	return ksys_fadvise64_64(fd, offset, len, advice);
 }
 
 #endif
-- 
cgit v1.2.3


From a90f590a1bee36fc2129cfb38ceec24a555bb12d Mon Sep 17 00:00:00 2001
From: Dominik Brodowski <linux@dominikbrodowski.net>
Date: Sun, 11 Mar 2018 11:34:46 +0100
Subject: mm: add ksys_mmap_pgoff() helper; remove in-kernel calls to
 sys_mmap_pgoff()

Using this helper allows us to avoid the in-kernel calls to the
sys_mmap_pgoff() syscall. The ksys_ prefix denotes that this function is
meant as a drop-in replacement for the syscall. In particular, it uses the
same calling convention as sys_mmap_pgoff().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
---
 arch/alpha/kernel/osf_sys.c             |  2 +-
 arch/arm64/kernel/sys.c                 |  2 +-
 arch/ia64/kernel/sys_ia64.c             |  4 ++--
 arch/m68k/kernel/sys_m68k.c             |  2 +-
 arch/microblaze/kernel/sys_microblaze.c |  6 +++---
 arch/mips/kernel/linux32.c              |  4 ++--
 arch/mips/kernel/syscall.c              |  6 ++++--
 arch/parisc/kernel/sys_parisc.c         |  6 +++---
 arch/powerpc/kernel/syscalls.c          |  2 +-
 arch/riscv/kernel/sys_riscv.c           |  4 ++--
 arch/s390/kernel/compat_linux.c         |  6 +++---
 arch/s390/kernel/sys_s390.c             |  2 +-
 arch/sh/kernel/sys_sh.c                 |  4 ++--
 arch/sparc/kernel/sys_sparc_32.c        |  6 +++---
 arch/sparc/kernel/sys_sparc_64.c        |  2 +-
 arch/um/kernel/syscall.c                |  2 +-
 arch/x86/ia32/sys_ia32.c                |  2 +-
 arch/x86/kernel/sys_x86_64.c            |  2 +-
 include/linux/syscalls.h                |  3 +++
 mm/mmap.c                               | 17 ++++++++++++-----
 mm/nommu.c                              | 17 ++++++++++++-----
 21 files changed, 60 insertions(+), 41 deletions(-)

(limited to 'arch/parisc')

diff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c
index fa1a392ca9a2..89faa6f4de47 100644
--- a/arch/alpha/kernel/osf_sys.c
+++ b/arch/alpha/kernel/osf_sys.c
@@ -189,7 +189,7 @@ SYSCALL_DEFINE6(osf_mmap, unsigned long, addr, unsigned long, len,
 		goto out;
 	if (off & ~PAGE_MASK)
 		goto out;
-	ret = sys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
+	ret = ksys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
  out:
 	return ret;
 }
diff --git a/arch/arm64/kernel/sys.c b/arch/arm64/kernel/sys.c
index 26fe8ea93ea2..72981bae10eb 100644
--- a/arch/arm64/kernel/sys.c
+++ b/arch/arm64/kernel/sys.c
@@ -34,7 +34,7 @@ asmlinkage long sys_mmap(unsigned long addr, unsigned long len,
 	if (offset_in_page(off) != 0)
 		return -EINVAL;
 
-	return sys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
+	return ksys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
 }
 
 SYSCALL_DEFINE1(arm64_personality, unsigned int, personality)
diff --git a/arch/ia64/kernel/sys_ia64.c b/arch/ia64/kernel/sys_ia64.c
index 085adfcc74a4..9ebe1d633abc 100644
--- a/arch/ia64/kernel/sys_ia64.c
+++ b/arch/ia64/kernel/sys_ia64.c
@@ -139,7 +139,7 @@ int ia64_mmap_check(unsigned long addr, unsigned long len,
 asmlinkage unsigned long
 sys_mmap2 (unsigned long addr, unsigned long len, int prot, int flags, int fd, long pgoff)
 {
-	addr = sys_mmap_pgoff(addr, len, prot, flags, fd, pgoff);
+	addr = ksys_mmap_pgoff(addr, len, prot, flags, fd, pgoff);
 	if (!IS_ERR((void *) addr))
 		force_successful_syscall_return();
 	return addr;
@@ -151,7 +151,7 @@ sys_mmap (unsigned long addr, unsigned long len, int prot, int flags, int fd, lo
 	if (offset_in_page(off) != 0)
 		return -EINVAL;
 
-	addr = sys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
+	addr = ksys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
 	if (!IS_ERR((void *) addr))
 		force_successful_syscall_return();
 	return addr;
diff --git a/arch/m68k/kernel/sys_m68k.c b/arch/m68k/kernel/sys_m68k.c
index 27e10af5153a..6363ec83a290 100644
--- a/arch/m68k/kernel/sys_m68k.c
+++ b/arch/m68k/kernel/sys_m68k.c
@@ -46,7 +46,7 @@ asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
 	 * so we need to shift the argument down by 1; m68k mmap64(3)
 	 * (in libc) expects the last argument of mmap2 in 4Kb units.
 	 */
-	return sys_mmap_pgoff(addr, len, prot, flags, fd, pgoff);
+	return ksys_mmap_pgoff(addr, len, prot, flags, fd, pgoff);
 }
 
 /* Convert virtual (user) address VADDR to physical address PADDR */
diff --git a/arch/microblaze/kernel/sys_microblaze.c b/arch/microblaze/kernel/sys_microblaze.c
index f1e1f666ddde..ed9f34da1a2a 100644
--- a/arch/microblaze/kernel/sys_microblaze.c
+++ b/arch/microblaze/kernel/sys_microblaze.c
@@ -40,7 +40,7 @@ SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
 	if (pgoff & ~PAGE_MASK)
 		return -EINVAL;
 
-	return sys_mmap_pgoff(addr, len, prot, flags, fd, pgoff >> PAGE_SHIFT);
+	return ksys_mmap_pgoff(addr, len, prot, flags, fd, pgoff >> PAGE_SHIFT);
 }
 
 SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
@@ -50,6 +50,6 @@ SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
 	if (pgoff & (~PAGE_MASK >> 12))
 		return -EINVAL;
 
-	return sys_mmap_pgoff(addr, len, prot, flags, fd,
-			      pgoff >> (PAGE_SHIFT - 12));
+	return ksys_mmap_pgoff(addr, len, prot, flags, fd,
+			       pgoff >> (PAGE_SHIFT - 12));
 }
diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c
index 1c5785e72db4..0571ab7b68b0 100644
--- a/arch/mips/kernel/linux32.c
+++ b/arch/mips/kernel/linux32.c
@@ -67,8 +67,8 @@ SYSCALL_DEFINE6(32_mmap2, unsigned long, addr, unsigned long, len,
 {
 	if (pgoff & (~PAGE_MASK >> 12))
 		return -EINVAL;
-	return sys_mmap_pgoff(addr, len, prot, flags, fd,
-			      pgoff >> (PAGE_SHIFT-12));
+	return ksys_mmap_pgoff(addr, len, prot, flags, fd,
+			       pgoff >> (PAGE_SHIFT-12));
 }
 
 #define RLIM_INFINITY32 0x7fffffff
diff --git a/arch/mips/kernel/syscall.c b/arch/mips/kernel/syscall.c
index 58c6f634b550..69c17b549fd3 100644
--- a/arch/mips/kernel/syscall.c
+++ b/arch/mips/kernel/syscall.c
@@ -63,7 +63,8 @@ SYSCALL_DEFINE6(mips_mmap, unsigned long, addr, unsigned long, len,
 {
 	if (offset & ~PAGE_MASK)
 		return -EINVAL;
-	return sys_mmap_pgoff(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);
+	return ksys_mmap_pgoff(addr, len, prot, flags, fd,
+			       offset >> PAGE_SHIFT);
 }
 
 SYSCALL_DEFINE6(mips_mmap2, unsigned long, addr, unsigned long, len,
@@ -73,7 +74,8 @@ SYSCALL_DEFINE6(mips_mmap2, unsigned long, addr, unsigned long, len,
 	if (pgoff & (~PAGE_MASK >> 12))
 		return -EINVAL;
 
-	return sys_mmap_pgoff(addr, len, prot, flags, fd, pgoff >> (PAGE_SHIFT-12));
+	return ksys_mmap_pgoff(addr, len, prot, flags, fd,
+			       pgoff >> (PAGE_SHIFT - 12));
 }
 
 save_static_function(sys_fork);
diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c
index f36ab1f09595..080d566654ea 100644
--- a/arch/parisc/kernel/sys_parisc.c
+++ b/arch/parisc/kernel/sys_parisc.c
@@ -270,8 +270,8 @@ asmlinkage unsigned long sys_mmap2(unsigned long addr, unsigned long len,
 {
 	/* Make sure the shift for mmap2 is constant (12), no matter what PAGE_SIZE
 	   we have. */
-	return sys_mmap_pgoff(addr, len, prot, flags, fd,
-			      pgoff >> (PAGE_SHIFT - 12));
+	return ksys_mmap_pgoff(addr, len, prot, flags, fd,
+			       pgoff >> (PAGE_SHIFT - 12));
 }
 
 asmlinkage unsigned long sys_mmap(unsigned long addr, unsigned long len,
@@ -279,7 +279,7 @@ asmlinkage unsigned long sys_mmap(unsigned long addr, unsigned long len,
 		unsigned long offset)
 {
 	if (!(offset & ~PAGE_MASK)) {
-		return sys_mmap_pgoff(addr, len, prot, flags, fd,
+		return ksys_mmap_pgoff(addr, len, prot, flags, fd,
 					offset >> PAGE_SHIFT);
 	} else {
 		return -EINVAL;
diff --git a/arch/powerpc/kernel/syscalls.c b/arch/powerpc/kernel/syscalls.c
index ecb981eea74b..1ef3b80b62a6 100644
--- a/arch/powerpc/kernel/syscalls.c
+++ b/arch/powerpc/kernel/syscalls.c
@@ -57,7 +57,7 @@ static inline long do_mmap2(unsigned long addr, size_t len,
 		off >>= shift;
 	}
 
-	ret = sys_mmap_pgoff(addr, len, prot, flags, fd, off);
+	ret = ksys_mmap_pgoff(addr, len, prot, flags, fd, off);
 out:
 	return ret;
 }
diff --git a/arch/riscv/kernel/sys_riscv.c b/arch/riscv/kernel/sys_riscv.c
index 79c78668258e..f7181ed8aafc 100644
--- a/arch/riscv/kernel/sys_riscv.c
+++ b/arch/riscv/kernel/sys_riscv.c
@@ -24,8 +24,8 @@ static long riscv_sys_mmap(unsigned long addr, unsigned long len,
 {
 	if (unlikely(offset & (~PAGE_MASK >> page_shift_offset)))
 		return -EINVAL;
-	return sys_mmap_pgoff(addr, len, prot, flags, fd,
-			      offset >> (PAGE_SHIFT - page_shift_offset));
+	return ksys_mmap_pgoff(addr, len, prot, flags, fd,
+			       offset >> (PAGE_SHIFT - page_shift_offset));
 }
 
 #ifdef CONFIG_64BIT
diff --git a/arch/s390/kernel/compat_linux.c b/arch/s390/kernel/compat_linux.c
index 9bb897e443a6..da5ef7718254 100644
--- a/arch/s390/kernel/compat_linux.c
+++ b/arch/s390/kernel/compat_linux.c
@@ -442,8 +442,8 @@ COMPAT_SYSCALL_DEFINE1(s390_old_mmap, struct mmap_arg_struct_emu31 __user *, arg
 		return -EFAULT;
 	if (a.offset & ~PAGE_MASK)
 		return -EINVAL;
-	return sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd,
-			      a.offset >> PAGE_SHIFT);
+	return ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd,
+			       a.offset >> PAGE_SHIFT);
 }
 
 COMPAT_SYSCALL_DEFINE1(s390_mmap2, struct mmap_arg_struct_emu31 __user *, arg)
@@ -452,7 +452,7 @@ COMPAT_SYSCALL_DEFINE1(s390_mmap2, struct mmap_arg_struct_emu31 __user *, arg)
 
 	if (copy_from_user(&a, arg, sizeof(a)))
 		return -EFAULT;
-	return sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
+	return ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
 }
 
 COMPAT_SYSCALL_DEFINE3(s390_read, unsigned int, fd, char __user *, buf, compat_size_t, count)
diff --git a/arch/s390/kernel/sys_s390.c b/arch/s390/kernel/sys_s390.c
index 0090037ab148..31cefe0c28c0 100644
--- a/arch/s390/kernel/sys_s390.c
+++ b/arch/s390/kernel/sys_s390.c
@@ -53,7 +53,7 @@ SYSCALL_DEFINE1(mmap2, struct s390_mmap_arg_struct __user *, arg)
 
 	if (copy_from_user(&a, arg, sizeof(a)))
 		goto out;
-	error = sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
+	error = ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
 out:
 	return error;
 }
diff --git a/arch/sh/kernel/sys_sh.c b/arch/sh/kernel/sys_sh.c
index 724911c59e7d..f8afc014e084 100644
--- a/arch/sh/kernel/sys_sh.c
+++ b/arch/sh/kernel/sys_sh.c
@@ -35,7 +35,7 @@ asmlinkage int old_mmap(unsigned long addr, unsigned long len,
 {
 	if (off & ~PAGE_MASK)
 		return -EINVAL;
-	return sys_mmap_pgoff(addr, len, prot, flags, fd, off>>PAGE_SHIFT);
+	return ksys_mmap_pgoff(addr, len, prot, flags, fd, off>>PAGE_SHIFT);
 }
 
 asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
@@ -51,7 +51,7 @@ asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
 
 	pgoff >>= PAGE_SHIFT - 12;
 
-	return sys_mmap_pgoff(addr, len, prot, flags, fd, pgoff);
+	return ksys_mmap_pgoff(addr, len, prot, flags, fd, pgoff);
 }
 
 /* sys_cacheflush -- flush (part of) the processor cache.  */
diff --git a/arch/sparc/kernel/sys_sparc_32.c b/arch/sparc/kernel/sys_sparc_32.c
index 990703b7cf4d..d980da4ffd7b 100644
--- a/arch/sparc/kernel/sys_sparc_32.c
+++ b/arch/sparc/kernel/sys_sparc_32.c
@@ -104,8 +104,8 @@ asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
 {
 	/* Make sure the shift for mmap2 is constant (12), no matter what PAGE_SIZE
 	   we have. */
-	return sys_mmap_pgoff(addr, len, prot, flags, fd,
-			      pgoff >> (PAGE_SHIFT - 12));
+	return ksys_mmap_pgoff(addr, len, prot, flags, fd,
+			       pgoff >> (PAGE_SHIFT - 12));
 }
 
 asmlinkage long sys_mmap(unsigned long addr, unsigned long len,
@@ -113,7 +113,7 @@ asmlinkage long sys_mmap(unsigned long addr, unsigned long len,
 	unsigned long off)
 {
 	/* no alignment check? */
-	return sys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
+	return ksys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
 }
 
 long sparc_remap_file_pages(unsigned long start, unsigned long size,
diff --git a/arch/sparc/kernel/sys_sparc_64.c b/arch/sparc/kernel/sys_sparc_64.c
index 55416db482ad..ebb84dc8a5a7 100644
--- a/arch/sparc/kernel/sys_sparc_64.c
+++ b/arch/sparc/kernel/sys_sparc_64.c
@@ -458,7 +458,7 @@ SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
 		goto out;
 	if (off & ~PAGE_MASK)
 		goto out;
-	retval = sys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
+	retval = ksys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
 out:
 	return retval;
 }
diff --git a/arch/um/kernel/syscall.c b/arch/um/kernel/syscall.c
index 6258676bed85..35f7047bdebc 100644
--- a/arch/um/kernel/syscall.c
+++ b/arch/um/kernel/syscall.c
@@ -22,7 +22,7 @@ long old_mmap(unsigned long addr, unsigned long len,
 	if (offset & ~PAGE_MASK)
 		goto out;
 
-	err = sys_mmap_pgoff(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);
+	err = ksys_mmap_pgoff(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);
  out:
 	return err;
 }
diff --git a/arch/x86/ia32/sys_ia32.c b/arch/x86/ia32/sys_ia32.c
index 401bd8ec9cf0..bff71b9ae3f5 100644
--- a/arch/x86/ia32/sys_ia32.c
+++ b/arch/x86/ia32/sys_ia32.c
@@ -166,7 +166,7 @@ COMPAT_SYSCALL_DEFINE1(x86_mmap, struct mmap_arg_struct32 __user *, arg)
 	if (a.offset & ~PAGE_MASK)
 		return -EINVAL;
 
-	return sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd,
+	return ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd,
 			       a.offset>>PAGE_SHIFT);
 }
 
diff --git a/arch/x86/kernel/sys_x86_64.c b/arch/x86/kernel/sys_x86_64.c
index 676774b9bb8d..a3f15ed545b5 100644
--- a/arch/x86/kernel/sys_x86_64.c
+++ b/arch/x86/kernel/sys_x86_64.c
@@ -97,7 +97,7 @@ SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
 	if (off & ~PAGE_MASK)
 		goto out;
 
-	error = sys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
+	error = ksys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
 out:
 	return error;
 }
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 466d408deefd..ec866c959e7d 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -979,6 +979,9 @@ static inline int ksys_fadvise64_64(int fd, loff_t offset, loff_t len,
 	return -EINVAL;
 }
 #endif
+unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len,
+			      unsigned long prot, unsigned long flags,
+			      unsigned long fd, unsigned long pgoff);
 
 /*
  * The following kernel syscall equivalents are just wrappers to fs-internal
diff --git a/mm/mmap.c b/mm/mmap.c
index 9efdc021ad22..aa0dc8231c0d 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1488,9 +1488,9 @@ unsigned long do_mmap(struct file *file, unsigned long addr,
 	return addr;
 }
 
-SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len,
-		unsigned long, prot, unsigned long, flags,
-		unsigned long, fd, unsigned long, pgoff)
+unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len,
+			      unsigned long prot, unsigned long flags,
+			      unsigned long fd, unsigned long pgoff)
 {
 	struct file *file = NULL;
 	unsigned long retval;
@@ -1537,6 +1537,13 @@ out_fput:
 	return retval;
 }
 
+SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len,
+		unsigned long, prot, unsigned long, flags,
+		unsigned long, fd, unsigned long, pgoff)
+{
+	return ksys_mmap_pgoff(addr, len, prot, flags, fd, pgoff);
+}
+
 #ifdef __ARCH_WANT_SYS_OLD_MMAP
 struct mmap_arg_struct {
 	unsigned long addr;
@@ -1556,8 +1563,8 @@ SYSCALL_DEFINE1(old_mmap, struct mmap_arg_struct __user *, arg)
 	if (offset_in_page(a.offset))
 		return -EINVAL;
 
-	return sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd,
-			      a.offset >> PAGE_SHIFT);
+	return ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd,
+			       a.offset >> PAGE_SHIFT);
 }
 #endif /* __ARCH_WANT_SYS_OLD_MMAP */
 
diff --git a/mm/nommu.c b/mm/nommu.c
index ebb6e618dade..cad329629530 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -1423,9 +1423,9 @@ error_getting_region:
 	return -ENOMEM;
 }
 
-SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len,
-		unsigned long, prot, unsigned long, flags,
-		unsigned long, fd, unsigned long, pgoff)
+unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len,
+			      unsigned long prot, unsigned long flags,
+			      unsigned long fd, unsigned long pgoff)
 {
 	struct file *file = NULL;
 	unsigned long retval = -EBADF;
@@ -1447,6 +1447,13 @@ out:
 	return retval;
 }
 
+SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len,
+		unsigned long, prot, unsigned long, flags,
+		unsigned long, fd, unsigned long, pgoff)
+{
+	return ksys_mmap_pgoff(addr, len, prot, flags, fd, pgoff);
+}
+
 #ifdef __ARCH_WANT_SYS_OLD_MMAP
 struct mmap_arg_struct {
 	unsigned long addr;
@@ -1466,8 +1473,8 @@ SYSCALL_DEFINE1(old_mmap, struct mmap_arg_struct __user *, arg)
 	if (offset_in_page(a.offset))
 		return -EINVAL;
 
-	return sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd,
-			      a.offset >> PAGE_SHIFT);
+	return ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd,
+			       a.offset >> PAGE_SHIFT);
 }
 #endif /* __ARCH_WANT_SYS_OLD_MMAP */
 
-- 
cgit v1.2.3


From c7b95d5156a9ee70f800bd2e47a9eba677be73e1 Mon Sep 17 00:00:00 2001
From: Dominik Brodowski <linux@dominikbrodowski.net>
Date: Mon, 19 Mar 2018 17:51:36 +0100
Subject: mm: add ksys_readahead() helper; remove in-kernel calls to
 sys_readahead()

Using this helper allows us to avoid the in-kernel calls to the
sys_readahead() syscall. The ksys_ prefix denotes that this function is
meant as a drop-in replacement for the syscall. In particular, it uses the
same calling convention as sys_readahead().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
---
 arch/mips/kernel/linux32.c      | 2 +-
 arch/parisc/kernel/sys_parisc.c | 2 +-
 arch/powerpc/kernel/sys_ppc32.c | 2 +-
 arch/s390/kernel/compat_linux.c | 2 +-
 arch/sparc/kernel/sys_sparc32.c | 2 +-
 arch/x86/ia32/sys_ia32.c        | 2 +-
 include/linux/syscalls.h        | 1 +
 mm/readahead.c                  | 7 ++++++-
 8 files changed, 13 insertions(+), 7 deletions(-)

(limited to 'arch/parisc')

diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c
index 0571ab7b68b0..318f1c05c5b3 100644
--- a/arch/mips/kernel/linux32.c
+++ b/arch/mips/kernel/linux32.c
@@ -131,7 +131,7 @@ SYSCALL_DEFINE1(32_personality, unsigned long, personality)
 asmlinkage ssize_t sys32_readahead(int fd, u32 pad0, u64 a2, u64 a3,
 				   size_t count)
 {
-	return sys_readahead(fd, merge_64(a2, a3), count);
+	return ksys_readahead(fd, merge_64(a2, a3), count);
 }
 
 asmlinkage long sys32_sync_file_range(int fd, int __pad,
diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c
index 080d566654ea..8c99ebbe2bac 100644
--- a/arch/parisc/kernel/sys_parisc.c
+++ b/arch/parisc/kernel/sys_parisc.c
@@ -345,7 +345,7 @@ asmlinkage ssize_t parisc_pwrite64(unsigned int fd, const char __user *buf,
 asmlinkage ssize_t parisc_readahead(int fd, unsigned int high, unsigned int low,
 		                    size_t count)
 {
-	return sys_readahead(fd, (loff_t)high << 32 | low, count);
+	return ksys_readahead(fd, (loff_t)high << 32 | low, count);
 }
 
 asmlinkage long parisc_fadvise64_64(int fd,
diff --git a/arch/powerpc/kernel/sys_ppc32.c b/arch/powerpc/kernel/sys_ppc32.c
index 0b95fa13307f..c11c73373691 100644
--- a/arch/powerpc/kernel/sys_ppc32.c
+++ b/arch/powerpc/kernel/sys_ppc32.c
@@ -88,7 +88,7 @@ compat_ssize_t compat_sys_pwrite64(unsigned int fd, const char __user *ubuf, com
 
 compat_ssize_t compat_sys_readahead(int fd, u32 r4, u32 offhi, u32 offlo, u32 count)
 {
-	return sys_readahead(fd, ((loff_t)offhi << 32) | offlo, count);
+	return ksys_readahead(fd, ((loff_t)offhi << 32) | offlo, count);
 }
 
 asmlinkage int compat_sys_truncate64(const char __user * path, u32 reg4,
diff --git a/arch/s390/kernel/compat_linux.c b/arch/s390/kernel/compat_linux.c
index da5ef7718254..8ac38d51ed7d 100644
--- a/arch/s390/kernel/compat_linux.c
+++ b/arch/s390/kernel/compat_linux.c
@@ -328,7 +328,7 @@ COMPAT_SYSCALL_DEFINE5(s390_pwrite64, unsigned int, fd, const char __user *, ubu
 
 COMPAT_SYSCALL_DEFINE4(s390_readahead, int, fd, u32, high, u32, low, s32, count)
 {
-	return sys_readahead(fd, (unsigned long)high << 32 | low, count);
+	return ksys_readahead(fd, (unsigned long)high << 32 | low, count);
 }
 
 struct stat64_emu31 {
diff --git a/arch/sparc/kernel/sys_sparc32.c b/arch/sparc/kernel/sys_sparc32.c
index 4da66aed50b4..f166e5bbf506 100644
--- a/arch/sparc/kernel/sys_sparc32.c
+++ b/arch/sparc/kernel/sys_sparc32.c
@@ -217,7 +217,7 @@ asmlinkage long compat_sys_readahead(int fd,
 				     unsigned long offlo,
 				     compat_size_t count)
 {
-	return sys_readahead(fd, (offhi << 32) | offlo, count);
+	return ksys_readahead(fd, (offhi << 32) | offlo, count);
 }
 
 long compat_sys_fadvise64(int fd,
diff --git a/arch/x86/ia32/sys_ia32.c b/arch/x86/ia32/sys_ia32.c
index bff71b9ae3f5..bd8a7020b9a7 100644
--- a/arch/x86/ia32/sys_ia32.c
+++ b/arch/x86/ia32/sys_ia32.c
@@ -203,7 +203,7 @@ COMPAT_SYSCALL_DEFINE6(x86_fadvise64_64, int, fd, __u32, offset_low,
 COMPAT_SYSCALL_DEFINE4(x86_readahead, int, fd, unsigned int, off_lo,
 		       unsigned int, off_hi, size_t, count)
 {
-	return sys_readahead(fd, ((u64)off_hi << 32) | off_lo, count);
+	return ksys_readahead(fd, ((u64)off_hi << 32) | off_lo, count);
 }
 
 COMPAT_SYSCALL_DEFINE6(x86_sync_file_range, int, fd, unsigned int, off_low,
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index ec866c959e7d..815fbdd9cca1 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -982,6 +982,7 @@ static inline int ksys_fadvise64_64(int fd, loff_t offset, loff_t len,
 unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len,
 			      unsigned long prot, unsigned long flags,
 			      unsigned long fd, unsigned long pgoff);
+ssize_t ksys_readahead(int fd, loff_t offset, size_t count);
 
 /*
  * The following kernel syscall equivalents are just wrappers to fs-internal
diff --git a/mm/readahead.c b/mm/readahead.c
index c4ca70239233..4d57b4644f98 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -573,7 +573,7 @@ do_readahead(struct address_space *mapping, struct file *filp,
 	return force_page_cache_readahead(mapping, filp, index, nr);
 }
 
-SYSCALL_DEFINE3(readahead, int, fd, loff_t, offset, size_t, count)
+ssize_t ksys_readahead(int fd, loff_t offset, size_t count)
 {
 	ssize_t ret;
 	struct fd f;
@@ -592,3 +592,8 @@ SYSCALL_DEFINE3(readahead, int, fd, loff_t, offset, size_t, count)
 	}
 	return ret;
 }
+
+SYSCALL_DEFINE3(readahead, int, fd, loff_t, offset, size_t, count)
+{
+	return ksys_readahead(fd, offset, count);
+}
-- 
cgit v1.2.3