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>
This commit is contained in:
Dominik Brodowski 2018-03-19 17:32:11 +01:00
parent 806cbae122
commit df260e21e6
8 changed files with 17 additions and 9 deletions

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@ -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,

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@ -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,

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@ -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,

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@ -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)

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@ -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)

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@ -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,

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@ -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;

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@ -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