Re: [PATCH v2 14/16] input: Redefine INPUT_COMPAT_TEST as in_compat_syscall()

[Andrew Morton <akpm@linux-foundation.org>]

On Wed, 27 Jan 2016 13:06:10 -0800 Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote:

> On Wed, Jan 27, 2016 at 12:29:14PM -0800, Andy Lutomirski wrote:
> > On Wed, Jan 27, 2016 at 11:17 AM, Dmitry Torokhov
> > <dmitry.torokhov@gmail.com> wrote:
> > > Hi Andy,
> > >
> > > On Mon, Jan 25, 2016 at 2:24 PM, Andy Lutomirski <luto@kernel.org> wrote:
> > >> The input compat code should work like all other compat code: for
> > >> 32-bit syscalls, use the 32-bit ABI and for 64-bit syscalls, use the
> > >> 64-bit ABI.  We have a helper for that (in_compat_syscall()): just
> > >> use it.
> > >>
> > >> Signed-off-by: Andy Lutomirski <luto@kernel.org>
> > >> ---
> > >>  drivers/input/input-compat.h | 12 +-----------
> > >>  1 file changed, 1 insertion(+), 11 deletions(-)
> > >>
> > >> diff --git a/drivers/input/input-compat.h b/drivers/input/input-compat.h
> > >> index 148f66fe3205..0f25878d5fa2 100644
> > >> --- a/drivers/input/input-compat.h
> > >> +++ b/drivers/input/input-compat.h
> > >> @@ -17,17 +17,7 @@
> > >>
> > >>  #ifdef CONFIG_COMPAT
> > >>
> > >> -/* Note to the author of this code: did it ever occur to
> > >> -   you why the ifdefs are needed? Think about it again. -AK */
> > >> -#if defined(CONFIG_X86_64) || defined(CONFIG_TILE)
> > >> -#  define INPUT_COMPAT_TEST is_compat_task()
> > >> -#elif defined(CONFIG_S390)
> > >> -#  define INPUT_COMPAT_TEST test_thread_flag(TIF_31BIT)
> > >> -#elif defined(CONFIG_MIPS)
> > >> -#  define INPUT_COMPAT_TEST test_thread_flag(TIF_32BIT_ADDR)
> > >> -#else
> > >> -#  define INPUT_COMPAT_TEST test_thread_flag(TIF_32BIT)
> > >> -#endif
> > >> +#define INPUT_COMPAT_TEST in_compat_syscall()
> > >>
> > >
> > >
> > > If we now have function that works on all arches I'd prefer if we used
> > > it directly instead of continuing using INPUT_COMPAT_TEST.
> > 
> > I'll write a followup patch for that if you don't beat me to it.
> 
> I promise I wont ;)

Well someone needs beating!

I'm prepping this patch for Linus now.  I shall queue up the below for
later.

From: Andrew Morton <akpm@linux-foundation.org>
Subject: drivers/input: eliminate INPUT_COMPAT_TEST macro

INPUT_COMPAT_TEST became much simpler after "input: redefine
INPUT_COMPAT_TEST as in_compat_syscall()" so we can cleanly eliminate it
altogether.

Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/input/input-compat.c |    6 +++---
 drivers/input/input-compat.h |    4 +---
 drivers/input/input.c        |    2 +-
 drivers/input/misc/uinput.c  |    4 ++--
 4 files changed, 7 insertions(+), 9 deletions(-)

diff -puN drivers/input/input-compat.h~a drivers/input/input-compat.h
--- a/drivers/input/input-compat.h~a
+++ a/drivers/input/input-compat.h
@@ -17,8 +17,6 @@
 
 #ifdef CONFIG_COMPAT
 
-#define INPUT_COMPAT_TEST in_compat_syscall()
-
 struct input_event_compat {
 	struct compat_timeval time;
 	__u16 type;
@@ -57,7 +55,7 @@ struct ff_effect_compat {
 
 static inline size_t input_event_size(void)
 {
-	return (INPUT_COMPAT_TEST && !COMPAT_USE_64BIT_TIME) ?
+	return (in_compat_syscall() && !COMPAT_USE_64BIT_TIME) ?
 		sizeof(struct input_event_compat) : sizeof(struct input_event);
 }
 
diff -puN drivers/input/misc/uinput.c~a drivers/input/misc/uinput.c
--- a/drivers/input/misc/uinput.c~a
+++ a/drivers/input/misc/uinput.c
@@ -664,7 +664,7 @@ struct uinput_ff_upload_compat {
 static int uinput_ff_upload_to_user(char __user *buffer,
 				    const struct uinput_ff_upload *ff_up)
 {
-	if (INPUT_COMPAT_TEST) {
+	if (in_compat_syscall()) {
 		struct uinput_ff_upload_compat ff_up_compat;
 
 		ff_up_compat.request_id = ff_up->request_id;
@@ -695,7 +695,7 @@ static int uinput_ff_upload_to_user(char
 static int uinput_ff_upload_from_user(const char __user *buffer,
 				      struct uinput_ff_upload *ff_up)
 {
-	if (INPUT_COMPAT_TEST) {
+	if (in_compat_syscall()) {
 		struct uinput_ff_upload_compat ff_up_compat;
 
 		if (copy_from_user(&ff_up_compat, buffer,
diff -puN drivers/input/input-compat.c~a drivers/input/input-compat.c
--- a/drivers/input/input-compat.c~a
+++ a/drivers/input/input-compat.c
@@ -17,7 +17,7 @@
 int input_event_from_user(const char __user *buffer,
 			  struct input_event *event)
 {
-	if (INPUT_COMPAT_TEST && !COMPAT_USE_64BIT_TIME) {
+	if (in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
 		struct input_event_compat compat_event;
 
 		if (copy_from_user(&compat_event, buffer,
@@ -41,7 +41,7 @@ int input_event_from_user(const char __u
 int input_event_to_user(char __user *buffer,
 			const struct input_event *event)
 {
-	if (INPUT_COMPAT_TEST && !COMPAT_USE_64BIT_TIME) {
+	if (in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
 		struct input_event_compat compat_event;
 
 		compat_event.time.tv_sec = event->time.tv_sec;
@@ -65,7 +65,7 @@ int input_event_to_user(char __user *buf
 int input_ff_effect_from_user(const char __user *buffer, size_t size,
 			      struct ff_effect *effect)
 {
-	if (INPUT_COMPAT_TEST) {
+	if (in_compat_syscall()) {
 		struct ff_effect_compat *compat_effect;
 
 		if (size != sizeof(struct ff_effect_compat))
diff -puN drivers/input/input.c~a drivers/input/input.c
--- a/drivers/input/input.c~a
+++ a/drivers/input/input.c
@@ -1015,7 +1015,7 @@ static int input_bits_to_string(char *bu
 {
 	int len = 0;
 
-	if (INPUT_COMPAT_TEST) {
+	if (in_compat_syscall()) {
 		u32 dword = bits >> 32;
 		if (dword || !skip_empty)
 			len += snprintf(buf, buf_size, "%x ", dword);
_