[PATCH] x86: document sysenter path

 *    for details.

 */

/*

 * The caller puts arg2 in %ecx, which gets pushed. The kernel will use

 * %ecx itself for arg2. The pushing is because the sysexit instruction

 * (found in entry.S) requires that we clobber %ecx with the desired %esp.

 * User code might expect that %ecx is unclobbered though, as it would be

 * for returning via the iret instruction, so we must push and pop.

 *

 * The caller puts arg3 in %edx, which the sysexit instruction requires

 * for %eip. Thus, exactly as for arg2, we must push and pop.

 *

 * Arg6 is different. The caller puts arg6 in %ebp. Since the sysenter

 * instruction clobbers %esp, the user's %esp won't even survive entry

 * into the kernel. We store %esp in %ebp. Code in entry.S must fetch

 * arg6 from the stack.

 */

	.text

	.globl __kernel_vsyscall

	.type __kernel_vsyscall,@function