[PATCH] Termio userspace access error handling

[PATCH] Termio userspace access error handling

[dhowells]

The attached patch creates a generic set of termio userspace access functions
with proper error handling. None of the current archs check for errors in this
case.

Signed-Off-By: dhowells@redhat.com
---
diffstat termio-2610rc1mm3.diff
 termios.h |   69 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 69 insertions(+)

diff -uNrp /warthog/kernels/linux-2.6.10-rc1-mm3/include/asm-generic/termios.h linux-2.6.10-rc1-mm3-frv/include/asm-generic/termios.h
--- /warthog/kernels/linux-2.6.10-rc1-mm3/include/asm-generic/termios.h	1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.10-rc1-mm3-frv/include/asm-generic/termios.h	2004-11-05 14:13:04.332459541 +0000
@@ -0,0 +1,69 @@
+/* termios.h: generic termios/termio user copying/translation
+ */
+
+#ifndef _ASM_GENERIC_TERMIOS_H
+#define _ASM_GENERIC_TERMIOS_H
+
+#include <asm/uaccess.h>
+
+#ifndef __ARCH_TERMIO_GETPUT
+
+/*
+ * Translate a "termio" structure into a "termios". Ugh.
+ */
+static inline int user_termio_to_kernel_termios(struct termios *termios,
+						struct termio __user *termio)
+{
+	unsigned short tmp;
+
+	if (get_user(tmp, &termio->c_iflag) < 0)
+		goto fault;
+	termios->c_iflag = (0xffff0000 & termios->c_iflag) | tmp;
+
+	if (get_user(tmp, &termio->c_oflag) < 0)
+		goto fault;
+	termios->c_oflag = (0xffff0000 & termios->c_oflag) | tmp;
+
+	if (get_user(tmp, &termio->c_cflag) < 0)
+		goto fault;
+	termios->c_cflag = (0xffff0000 & termios->c_cflag) | tmp;
+
+	if (get_user(tmp, &termio->c_lflag) < 0)
+		goto fault;
+	termios->c_lflag = (0xffff0000 & termios->c_lflag) | tmp;
+
+	if (get_user(termios->c_line, &termio->c_line) < 0)
+		goto fault;
+
+	if (copy_from_user(termios->c_cc, termio->c_cc, NCC) != 0)
+		goto fault;
+
+	return 0;
+
+ fault:
+	return -EFAULT;
+}
+
+/*
+ * Translate a "termios" structure into a "termio". Ugh.
+ */
+static inline int kernel_termios_to_user_termio(struct termio __user *termio,
+						struct termios *termios)
+{
+	if (put_user(termios->c_iflag, &termio->c_iflag) < 0 ||
+	    put_user(termios->c_oflag, &termio->c_oflag) < 0 ||
+	    put_user(termios->c_cflag, &termio->c_cflag) < 0 ||
+	    put_user(termios->c_lflag, &termio->c_lflag) < 0 ||
+	    put_user(termios->c_line,  &termio->c_line) < 0 ||
+	    copy_to_user(termio->c_cc, termios->c_cc, NCC) != 0)
+		return -EFAULT;
+
+	return 0;
+}
+
+#define user_termios_to_kernel_termios(k, u) copy_from_user(k, u, sizeof(struct termios))
+#define kernel_termios_to_user_termios(u, k) copy_to_user(u, k, sizeof(struct termios))
+
+#endif	/* __ARCH_TERMIO_GETPUT */
+
+#endif /* _ASM_GENERIC_TERMIOS_H */

Re: [PATCH] Termio userspace access error handling

[Andrew Morton]

dhowells@redhat.com wrote:
>
> The attached patch creates a generic set of termio userspace access functions
> with proper error handling. None of the current archs check for errors in this
> case.

Why are they inlined?

Re: [PATCH] Termio userspace access error handling

[David Howells]

Andrew Morton <akpm@osdl.org> wrote:
> > The attached patch creates a generic set of termio userspace access
> > functions with proper error handling. None of the current archs check for
> > errors in this case.
> 
> Why are they inlined?

Each function is used a single time. Also they can't just be integrated into
the calling functions though because some archs need to handle them
differently.

David