lkml.org 
[lkml]   [2019]   [Nov]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.4 29/75] ARM: uaccess: remove put_user() code duplication
Date
From: Russell King <rmk+kernel@arm.linux.org.uk>

Commit 9f73bd8bb445e0cbe4bcef6d4cfc788f1e184007 upstream.

Remove the code duplication between put_user() and __put_user(). The
code which selected the implementation based upon the pointer size, and
declared the local variable to hold the value to be put are common to
both implementations.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/arm/include/asm/uaccess.h | 106 ++++++++++++++++++-----------------------
1 file changed, 49 insertions(+), 57 deletions(-)

--- a/arch/arm/include/asm/uaccess.h
+++ b/arch/arm/include/asm/uaccess.h
@@ -238,49 +238,23 @@ extern int __put_user_2(void *, unsigned
extern int __put_user_4(void *, unsigned int);
extern int __put_user_8(void *, unsigned long long);

-#define __put_user_x(__r2, __p, __e, __l, __s) \
- __asm__ __volatile__ ( \
- __asmeq("%0", "r0") __asmeq("%2", "r2") \
- __asmeq("%3", "r1") \
- "bl __put_user_" #__s \
- : "=&r" (__e) \
- : "0" (__p), "r" (__r2), "r" (__l) \
- : "ip", "lr", "cc")
-
-#define __put_user_check(x, p) \
+#define __put_user_check(__pu_val, __ptr, __err, __s) \
({ \
unsigned long __limit = current_thread_info()->addr_limit - 1; \
- const typeof(*(p)) __user *__tmp_p = (p); \
- register const typeof(*(p)) __r2 asm("r2") = (x); \
- register const typeof(*(p)) __user *__p asm("r0") = __tmp_p; \
+ register typeof(__pu_val) __r2 asm("r2") = __pu_val; \
+ register const void __user *__p asm("r0") = __ptr; \
register unsigned long __l asm("r1") = __limit; \
register int __e asm("r0"); \
- unsigned int __ua_flags = uaccess_save_and_enable(); \
- switch (sizeof(*(__p))) { \
- case 1: \
- __put_user_x(__r2, __p, __e, __l, 1); \
- break; \
- case 2: \
- __put_user_x(__r2, __p, __e, __l, 2); \
- break; \
- case 4: \
- __put_user_x(__r2, __p, __e, __l, 4); \
- break; \
- case 8: \
- __put_user_x(__r2, __p, __e, __l, 8); \
- break; \
- default: __e = __put_user_bad(); break; \
- } \
- uaccess_restore(__ua_flags); \
- __e; \
+ __asm__ __volatile__ ( \
+ __asmeq("%0", "r0") __asmeq("%2", "r2") \
+ __asmeq("%3", "r1") \
+ "bl __put_user_" #__s \
+ : "=&r" (__e) \
+ : "0" (__p), "r" (__r2), "r" (__l) \
+ : "ip", "lr", "cc"); \
+ __err = __e; \
})

-#define put_user(x, p) \
- ({ \
- might_fault(); \
- __put_user_check(x, p); \
- })
-
#else /* CONFIG_MMU */

/*
@@ -298,7 +272,7 @@ static inline void set_fs(mm_segment_t f
}

#define get_user(x, p) __get_user(x, p)
-#define put_user(x, p) __put_user(x, p)
+#define __put_user_check __put_user_nocheck

#endif /* CONFIG_MMU */

@@ -389,36 +363,54 @@ do { \
#define __get_user_asm_word(x, addr, err) \
__get_user_asm(x, addr, err, ldr)

+
+#define __put_user_switch(x, ptr, __err, __fn) \
+ do { \
+ const __typeof__(*(ptr)) __user *__pu_ptr = (ptr); \
+ __typeof__(*(ptr)) __pu_val = (x); \
+ unsigned int __ua_flags; \
+ might_fault(); \
+ __ua_flags = uaccess_save_and_enable(); \
+ switch (sizeof(*(ptr))) { \
+ case 1: __fn(__pu_val, __pu_ptr, __err, 1); break; \
+ case 2: __fn(__pu_val, __pu_ptr, __err, 2); break; \
+ case 4: __fn(__pu_val, __pu_ptr, __err, 4); break; \
+ case 8: __fn(__pu_val, __pu_ptr, __err, 8); break; \
+ default: __err = __put_user_bad(); break; \
+ } \
+ uaccess_restore(__ua_flags); \
+ } while (0)
+
+#define put_user(x, ptr) \
+({ \
+ int __pu_err = 0; \
+ __put_user_switch((x), (ptr), __pu_err, __put_user_check); \
+ __pu_err; \
+})
+
#define __put_user(x, ptr) \
({ \
long __pu_err = 0; \
- __put_user_err((x), (ptr), __pu_err); \
+ __put_user_switch((x), (ptr), __pu_err, __put_user_nocheck); \
__pu_err; \
})

#define __put_user_error(x, ptr, err) \
({ \
- __put_user_err((x), (ptr), err); \
+ __put_user_switch((x), (ptr), (err), __put_user_nocheck); \
(void) 0; \
})

-#define __put_user_err(x, ptr, err) \
-do { \
- unsigned long __pu_addr = (unsigned long)(ptr); \
- unsigned int __ua_flags; \
- __typeof__(*(ptr)) __pu_val = (x); \
- __chk_user_ptr(ptr); \
- might_fault(); \
- __ua_flags = uaccess_save_and_enable(); \
- switch (sizeof(*(ptr))) { \
- case 1: __put_user_asm_byte(__pu_val, __pu_addr, err); break; \
- case 2: __put_user_asm_half(__pu_val, __pu_addr, err); break; \
- case 4: __put_user_asm_word(__pu_val, __pu_addr, err); break; \
- case 8: __put_user_asm_dword(__pu_val, __pu_addr, err); break; \
- default: __put_user_bad(); \
- } \
- uaccess_restore(__ua_flags); \
-} while (0)
+#define __put_user_nocheck(x, __pu_ptr, __err, __size) \
+ do { \
+ unsigned long __pu_addr = (unsigned long)__pu_ptr; \
+ __put_user_nocheck_##__size(x, __pu_addr, __err); \
+ } while (0)
+
+#define __put_user_nocheck_1 __put_user_asm_byte
+#define __put_user_nocheck_2 __put_user_asm_half
+#define __put_user_nocheck_4 __put_user_asm_word
+#define __put_user_nocheck_8 __put_user_asm_dword

#define __put_user_asm(x, __pu_addr, err, instr) \
__asm__ __volatile__( \

\
 
 \ /
  Last update: 2019-11-08 19:54    [W:0.195 / U:27.996 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site