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mm: add ksys_mmap_pgoff() helper; remove in-kernel calls to sys_mmap_pgoff()

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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>
This commit is contained in:
Dominik Brodowski 2018-03-11 11:34:46 +01:00
parent 9d5b7c956b
commit a90f590a1b
21 changed files with 60 additions and 41 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/alpha/kernel/osf_sys.c
View File

@ -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;
}

2
arch/arm64/kernel/sys.c
View File

@ -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)

4
arch/ia64/kernel/sys_ia64.c
View File

@ -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;

2
arch/m68k/kernel/sys_m68k.c
View File

@ -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 */

4
arch/microblaze/kernel/sys_microblaze.c
View File

@ -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,
return ksys_mmap_pgoff(addr, len, prot, flags, fd,
pgoff >> (PAGE_SHIFT - 12));
}

2
arch/mips/kernel/linux32.c
View File

@ -67,7 +67,7 @@ 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,
return ksys_mmap_pgoff(addr, len, prot, flags, fd,
pgoff >> (PAGE_SHIFT-12));
}

6
arch/mips/kernel/syscall.c
View File

@ -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);

4
arch/parisc/kernel/sys_parisc.c
View File

@ -270,7 +270,7 @@ 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,
return ksys_mmap_pgoff(addr, len, prot, flags, fd,
pgoff >> (PAGE_SHIFT - 12));
}
@ -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;

2
arch/powerpc/kernel/syscalls.c
View File

@ -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;
}

2
arch/riscv/kernel/sys_riscv.c
View File

@ -24,7 +24,7 @@ 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,
return ksys_mmap_pgoff(addr, len, prot, flags, fd,
offset >> (PAGE_SHIFT - page_shift_offset));
}

4
arch/s390/kernel/compat_linux.c
View File

@ -442,7 +442,7 @@ 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,
return ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd,
a.offset >> PAGE_SHIFT);
}
@ -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)

2
arch/s390/kernel/sys_s390.c
View File

@ -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;
}

4
arch/sh/kernel/sys_sh.c
View File

@ -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. */

4
arch/sparc/kernel/sys_sparc_32.c
View File

@ -104,7 +104,7 @@ 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,
return ksys_mmap_pgoff(addr, len, prot, flags, fd,
pgoff >> (PAGE_SHIFT - 12));
}
@ -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,

2
arch/sparc/kernel/sys_sparc_64.c
View File

@ -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;
}

2
arch/um/kernel/syscall.c
View File

@ -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;
}

2
arch/x86/ia32/sys_ia32.c
View File

@ -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);
}

2
arch/x86/kernel/sys_x86_64.c
View File

@ -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;
}

3
include/linux/syscalls.h
View File

@ -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

15
mm/mmap.c
View File

@ -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;
@ -1556,7 +1563,7 @@ 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,
return ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd,
a.offset >> PAGE_SHIFT);
}
#endif /* __ARCH_WANT_SYS_OLD_MMAP */

15
mm/nommu.c
View File

@ -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;
@ -1466,7 +1473,7 @@ 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,
return ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd,
a.offset >> PAGE_SHIFT);
}
#endif /* __ARCH_WANT_SYS_OLD_MMAP */