Commit 05585e44 authored by Dominik Brodowski's avatar Dominik Brodowski
Browse files

fs: add do_compat_select() helper; remove in-kernel call to compat syscall 

Using the fs-internal do_compat_select() helper allows us to get rid of
the fs-internal call to the compat_sys_select() syscall.

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: default avatarDominik Brodowski <linux@dominikbrodowski.net>
parent e02af2ff

fs/select.c

+12 −5
Original line number Diff line number Diff line
@@ -1265,9 +1265,9 @@ static int compat_core_sys_select(int n, compat_ulong_t __user *inp, 
	return ret;

}



COMPAT_SYSCALL_DEFINE5(select, int, n, compat_ulong_t __user *, inp,

	compat_ulong_t __user *, outp, compat_ulong_t __user *, exp,

	struct compat_timeval __user *, tvp)

static int do_compat_select(int n, compat_ulong_t __user *inp,

	compat_ulong_t __user *outp, compat_ulong_t __user *exp,

	struct compat_timeval __user *tvp)

{

	struct timespec64 end_time, *to = NULL;

	struct compat_timeval tv;
@@ -1290,6 +1290,13 @@ COMPAT_SYSCALL_DEFINE5(select, int, n, compat_ulong_t __user *, inp, 
	return ret;

}



COMPAT_SYSCALL_DEFINE5(select, int, n, compat_ulong_t __user *, inp,

	compat_ulong_t __user *, outp, compat_ulong_t __user *, exp,

	struct compat_timeval __user *, tvp)

{

	return do_compat_select(n, inp, outp, exp, tvp);

}



struct compat_sel_arg_struct {

	compat_ulong_t n;

	compat_uptr_t inp;
@@ -1304,7 +1311,7 @@ COMPAT_SYSCALL_DEFINE1(old_select, struct compat_sel_arg_struct __user *, arg) 


	if (copy_from_user(&a, arg, sizeof(a)))

		return -EFAULT;

	return compat_sys_select(a.n, compat_ptr(a.inp), compat_ptr(a.outp),

	return do_compat_select(a.n, compat_ptr(a.inp), compat_ptr(a.outp),

				compat_ptr(a.exp), compat_ptr(a.tvp));

}