lkml.org 
[lkml]   [2018]   [Mar]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 098/109] mm: add ksys_readahead() helper; remove in-kernel calls to sys_readahead()
    Date
    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(-)

    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);
    +}
    --
    2.16.3
    \
     
     \ /
      Last update: 2018-03-29 13:58    [W:4.239 / U:0.024 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site