Re: [PATCH] x86/uaccess: Remove unused __addr_ok() macro

From: Christian Kujau
Date: Mon Mar 04 2019 - 01:47:05 EST


On Mon, 25 Feb 2019, Joe Perches wrote:
> Looks like it's not used in several arches
>
> $ git grep -w __addr_ok
> arch/arm/include/asm/uaccess.h:#define __addr_ok(addr) ((void)(addr), 1)
> arch/csky/include/asm/uaccess.h:#define __addr_ok(addr) (access_ok(addr, 0))
> arch/openrisc/include/asm/uaccess.h:#define __addr_ok(addr) ((unsigned long) addr < get_fs())
> arch/sh/include/asm/uaccess.h:#define __addr_ok(addr) \
> arch/sh/include/asm/uaccess.h: __ao_end >= __ao_a && __addr_ok(__ao_end); })
> arch/x86/include/asm/uaccess.h:#define __addr_ok(addr) \

If so, would simly removing it do the trick or is there more magic
involved? I don't have that many cross-compilers though and it's not even
build-tested:


commit f899653c64cce05fde426d0298cd67670f8ab8e2
Author: Christian Kujau <lists@xxxxxxxxxxxxxxx>
Date: Sun Mar 3 22:43:09 2019 -0800

Remove unused __addr_ok() macro.

arch/arm/include/asm/uaccess.h | 1 -
arch/csky/include/asm/uaccess.h | 2 --
arch/openrisc/include/asm/uaccess.h | 3 ---
arch/sh/include/asm/uaccess.h | 5 +----
arch/x86/include/asm/uaccess.h | 2 --
5 files changed, 1 insertion(+), 12 deletions(-)

Signed-off-by: Christian Kujau <lists@xxxxxxxxxxxxxxx>

diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h
index 42aa4a22803c..16411c76076d 100644
--- a/arch/arm/include/asm/uaccess.h
+++ b/arch/arm/include/asm/uaccess.h
@@ -266,7 +266,6 @@ extern int __put_user_8(void *, unsigned long long);
#define USER_DS KERNEL_DS

#define segment_eq(a, b) (1)
-#define __addr_ok(addr) ((void)(addr), 1)
#define __range_ok(addr, size) ((void)(addr), 0)
#define get_fs() (KERNEL_DS)

diff --git a/arch/csky/include/asm/uaccess.h b/arch/csky/include/asm/uaccess.h
index eaa1c3403a42..c02b243fecaa 100644
--- a/arch/csky/include/asm/uaccess.h
+++ b/arch/csky/include/asm/uaccess.h
@@ -24,8 +24,6 @@ static inline int access_ok(const void *addr, unsigned long size)
((unsigned long)(addr + size) < limit));
}

-#define __addr_ok(addr) (access_ok(addr, 0))
-
extern int __put_user_bad(void);

/*
diff --git a/arch/openrisc/include/asm/uaccess.h b/arch/openrisc/include/asm/uaccess.h
index a44682c8adc3..9198371e30c2 100644
--- a/arch/openrisc/include/asm/uaccess.h
+++ b/arch/openrisc/include/asm/uaccess.h
@@ -55,9 +55,6 @@
*/
#define __range_ok(addr, size) (size <= get_fs() && addr <= (get_fs()-size))

-/* Ensure that addr is below task's addr_limit */
-#define __addr_ok(addr) ((unsigned long) addr < get_fs())
-
#define access_ok(addr, size) \
({ \
unsigned long __ao_addr = (unsigned long)(addr); \
diff --git a/arch/sh/include/asm/uaccess.h b/arch/sh/include/asm/uaccess.h
index 5fe751ad7582..b41f6a011474 100644
--- a/arch/sh/include/asm/uaccess.h
+++ b/arch/sh/include/asm/uaccess.h
@@ -5,9 +5,6 @@
#include <asm/segment.h>
#include <asm/extable.h>

-#define __addr_ok(addr) \
- ((unsigned long __force)(addr) < current_thread_info()->addr_limit.seg)
-
/*
* __access_ok: Check if address with size is OK or not.
*
@@ -19,7 +16,7 @@
#define __access_ok(addr, size) ({ \
unsigned long __ao_a = (addr), __ao_b = (size); \
unsigned long __ao_end = __ao_a + __ao_b - !!__ao_b; \
- __ao_end >= __ao_a && __addr_ok(__ao_end); })
+ __ao_end >= __ao_a; })

#define access_ok(addr, size) \
(__chk_user_ptr(addr), \
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index c1334aaaa78d..d630978738dc 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -37,8 +37,6 @@ static inline void set_fs(mm_segment_t fs)
#define segment_eq(a, b) ((a).seg == (b).seg)

#define user_addr_max() (current->thread.addr_limit.seg)
-#define __addr_ok(addr) \
- ((unsigned long __force)(addr) < user_addr_max())

/*
* Test whether a block of memory is a valid user space address.


--
BOFH excuse #123:

user to computer ratio too high.