[RFC PATCH 33/35] syscalls: do not call sys_ftruncate() within the kernel

From: Dominik Brodowski
Date: Sun Mar 11 2018 - 06:58:41 EST


CC: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx>
---
arch/mips/kernel/linux32.c | 2 +-
arch/parisc/kernel/sys_parisc.c | 4 ++--
arch/powerpc/kernel/sys_ppc32.c | 2 +-
arch/s390/kernel/compat_linux.c | 2 +-
arch/sparc/kernel/sys_sparc32.c | 2 +-
arch/tile/kernel/compat.c | 2 +-
arch/x86/ia32/sys_ia32.c | 2 +-
fs/internal.h | 1 +
fs/open.c | 2 +-
include/linux/syscalls.h | 6 ++++++
init/initramfs.c | 2 +-
11 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c
index db895771ab06..740eee40c668 100644
--- a/arch/mips/kernel/linux32.c
+++ b/arch/mips/kernel/linux32.c
@@ -88,7 +88,7 @@ SYSCALL_DEFINE4(32_truncate64, const char __user *, path,
SYSCALL_DEFINE4(32_ftruncate64, unsigned long, fd, unsigned long, __dummy,
unsigned long, a2, unsigned long, a3)
{
- return sys_ftruncate(fd, merge_64(a2, a3));
+ return ksys_ftruncate(fd, merge_64(a2, a3));
}

SYSCALL_DEFINE5(32_llseek, unsigned int, fd, unsigned int, offset_high,
diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c
index 0b0e1cfb4bd9..59b315d6d194 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)
{
diff --git a/arch/powerpc/kernel/sys_ppc32.c b/arch/powerpc/kernel/sys_ppc32.c
index 3871aa9267e6..f41cb34c84c8 100644
--- a/arch/powerpc/kernel/sys_ppc32.c
+++ b/arch/powerpc/kernel/sys_ppc32.c
@@ -107,7 +107,7 @@ asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offhi, u32 offlo,
asmlinkage int compat_sys_ftruncate64(unsigned int fd, u32 reg4, unsigned long high,
unsigned long low)
{
- return sys_ftruncate(fd, (high << 32) | low);
+ return ksys_ftruncate(fd, (high << 32) | low);
}

long ppc32_fadvise64(int fd, u32 unused, u32 offset_high, u32 offset_low,
diff --git a/arch/s390/kernel/compat_linux.c b/arch/s390/kernel/compat_linux.c
index 82e99bf3b00e..572349852b75 100644
--- a/arch/s390/kernel/compat_linux.c
+++ b/arch/s390/kernel/compat_linux.c
@@ -307,7 +307,7 @@ COMPAT_SYSCALL_DEFINE3(s390_truncate64, const char __user *, path, u32, high, u3

COMPAT_SYSCALL_DEFINE3(s390_ftruncate64, unsigned int, fd, u32, high, u32, low)
{
- return sys_ftruncate(fd, (unsigned long)high << 32 | low);
+ return ksys_ftruncate(fd, (unsigned long)high << 32 | low);
}

COMPAT_SYSCALL_DEFINE5(s390_pread64, unsigned int, fd, char __user *, ubuf,
diff --git a/arch/sparc/kernel/sys_sparc32.c b/arch/sparc/kernel/sys_sparc32.c
index c56f43893283..f8d357540748 100644
--- a/arch/sparc/kernel/sys_sparc32.c
+++ b/arch/sparc/kernel/sys_sparc32.c
@@ -65,7 +65,7 @@ asmlinkage long sys32_ftruncate64(unsigned int fd, unsigned long high, unsigned
if ((int)high < 0)
return -EINVAL;
else
- return sys_ftruncate(fd, (high << 32) | low);
+ return ksys_ftruncate(fd, (high << 32) | low);
}

static int cp_compat_stat64(struct kstat *stat,
diff --git a/arch/tile/kernel/compat.c b/arch/tile/kernel/compat.c
index 24414d4d592d..d1fff2b0dade 100644
--- a/arch/tile/kernel/compat.c
+++ b/arch/tile/kernel/compat.c
@@ -48,7 +48,7 @@ COMPAT_SYSCALL_DEFINE4(truncate64, char __user *, filename, u32, dummy,
COMPAT_SYSCALL_DEFINE4(ftruncate64, unsigned int, fd, u32, dummy,
SYSCALL_PAIR(length))
{
- return sys_ftruncate(fd, ((loff_t)length_hi << 32) | length_lo);
+ return ksys_ftruncate(fd, ((loff_t)length_hi << 32) | length_lo);
}

COMPAT_SYSCALL_DEFINE6(pread64, unsigned int, fd, char __user *, ubuf,
diff --git a/arch/x86/ia32/sys_ia32.c b/arch/x86/ia32/sys_ia32.c
index 42badedd5ebc..3bac9e81a363 100644
--- a/arch/x86/ia32/sys_ia32.c
+++ b/arch/x86/ia32/sys_ia32.c
@@ -61,7 +61,7 @@ asmlinkage long sys32_truncate64(const char __user *filename,
asmlinkage long sys32_ftruncate64(unsigned int fd, unsigned long offset_low,
unsigned long offset_high)
{
- return sys_ftruncate(fd, ((loff_t) offset_high << 32) | offset_low);
+ return ksys_ftruncate(fd, ((loff_t) offset_high << 32) | offset_low);
}

/*
diff --git a/fs/internal.h b/fs/internal.h
index 26f4f05b52ef..49e0bf51576c 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -119,6 +119,7 @@ extern struct file *do_filp_open(int dfd, struct filename *pathname,
extern struct file *do_file_open_root(struct dentry *, struct vfsmount *,
const char *, const struct open_flags *);

+long do_sys_ftruncate(unsigned int fd, loff_t length, int small);
long do_faccessat(int dfd, const char __user *filename, int mode);
int do_fchmodat(int dfd, const char __user *filename, umode_t mode);

diff --git a/fs/open.c b/fs/open.c
index 0fc8188be31a..77a4494f605d 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -162,7 +162,7 @@ COMPAT_SYSCALL_DEFINE2(truncate, const char __user *, path, compat_off_t, length
}
#endif

-static long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
+long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
{
struct inode *inode;
struct dentry *dentry;
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index ac4ba9439e52..ebb8eb458415 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -1022,4 +1022,10 @@ static inline long ksys_access(const char __user *filename, int mode)
return do_faccessat(AT_FDCWD, filename, mode);
}

+extern long do_sys_ftruncate(unsigned int fd, loff_t length, int small);
+static inline long ksys_ftruncate(unsigned int fd, unsigned long length)
+{
+ return do_sys_ftruncate(fd, length, 1);
+}
+
#endif
diff --git a/init/initramfs.c b/init/initramfs.c
index 16c3c23076e2..237a975738ba 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -346,7 +346,7 @@ static int __init do_name(void)
sys_fchown(wfd, uid, gid);
ksys_fchmod(wfd, mode);
if (body_len)
- sys_ftruncate(wfd, body_len);
+ ksys_ftruncate(wfd, body_len);
vcollected = kstrdup(collected, GFP_KERNEL);
state = CopyFile;
}
--
2.16.2