[PATCH] i386: more vsyscall documentation

Document a limitation of vsyscall-sysenter, since patches to fix it have
been rejected.

Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/arch/i386/kernel/vsyscall-sysenter.S b/arch/i386/kernel/vsyscall-sysenter.S
index 76b7281..3b62baa 100644 (file)
--- a/arch/i386/kernel/vsyscall-sysenter.S
+++ b/arch/i386/kernel/vsyscall-sysenter.S
@@ -21,6 +21,9 @@
  * 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.
+ *
+ * You can not use this vsyscall for the clone() syscall because the
+ * three dwords on the parent stack do not get copied to the child.
  */
        .text
        .globl __kernel_vsyscall