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>
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@@ -442,8 +442,8 @@ COMPAT_SYSCALL_DEFINE1(s390_old_mmap, struct mmap_arg_struct_emu31 __user *, arg
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return -EFAULT;
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if (a.offset & ~PAGE_MASK)
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return -EINVAL;
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return sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd,
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a.offset >> PAGE_SHIFT);
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return ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd,
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a.offset >> PAGE_SHIFT);
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}
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COMPAT_SYSCALL_DEFINE1(s390_mmap2, struct mmap_arg_struct_emu31 __user *, arg)
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@@ -452,7 +452,7 @@ COMPAT_SYSCALL_DEFINE1(s390_mmap2, struct mmap_arg_struct_emu31 __user *, arg)
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if (copy_from_user(&a, arg, sizeof(a)))
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return -EFAULT;
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return sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
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return ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
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}
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COMPAT_SYSCALL_DEFINE3(s390_read, unsigned int, fd, char __user *, buf, compat_size_t, count)
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@@ -53,7 +53,7 @@ SYSCALL_DEFINE1(mmap2, struct s390_mmap_arg_struct __user *, arg)
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if (copy_from_user(&a, arg, sizeof(a)))
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goto out;
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error = sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
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error = ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
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out:
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return error;
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}
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