[ARM] nommu: uaccess tweaks
MMUless systems have only one address space for all threads, so both the usual access_ok() checks, and the exception handling do not make much sense. Hence, discard the fixup and exception tables at link time, use memcpy/memset for the user copy/clearing functions, and define the permission check macros to be constants. Some of this patch was derived from the equivalent patch by Hyok S. Choi. Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Russell King
Russell King
parent
002547b4f8
commit
9641c7cc5a
4 changed files with 108 additions and 59 deletions
|
|
@ -109,11 +109,13 @@ EXPORT_SYMBOL(memchr);
|
|||
EXPORT_SYMBOL(__memzero);
|
||||
|
||||
/* user mem (segment) */
|
||||
EXPORT_SYMBOL(__strnlen_user);
|
||||
EXPORT_SYMBOL(__strncpy_from_user);
|
||||
|
||||
#ifdef CONFIG_MMU
|
||||
EXPORT_SYMBOL(__copy_from_user);
|
||||
EXPORT_SYMBOL(__copy_to_user);
|
||||
EXPORT_SYMBOL(__clear_user);
|
||||
EXPORT_SYMBOL(__strnlen_user);
|
||||
EXPORT_SYMBOL(__strncpy_from_user);
|
||||
|
||||
EXPORT_SYMBOL(__get_user_1);
|
||||
EXPORT_SYMBOL(__get_user_2);
|
||||
|
|
@ -123,6 +125,7 @@ EXPORT_SYMBOL(__put_user_1);
|
|||
EXPORT_SYMBOL(__put_user_2);
|
||||
EXPORT_SYMBOL(__put_user_4);
|
||||
EXPORT_SYMBOL(__put_user_8);
|
||||
#endif
|
||||
|
||||
/* crypto hash */
|
||||
EXPORT_SYMBOL(sha_transform);
|
||||
|
|
|
|||
|
|
@ -80,6 +80,10 @@ SECTIONS
|
|||
*(.exit.text)
|
||||
*(.exit.data)
|
||||
*(.exitcall.exit)
|
||||
#ifndef CONFIG_MMU
|
||||
*(.fixup)
|
||||
*(__ex_table)
|
||||
#endif
|
||||
}
|
||||
|
||||
.text : { /* Real text segment */
|
||||
|
|
@ -87,7 +91,9 @@ SECTIONS
|
|||
*(.text)
|
||||
SCHED_TEXT
|
||||
LOCK_TEXT
|
||||
#ifdef CONFIG_MMU
|
||||
*(.fixup)
|
||||
#endif
|
||||
*(.gnu.warning)
|
||||
*(.rodata)
|
||||
*(.rodata.*)
|
||||
|
|
@ -142,7 +148,9 @@ SECTIONS
|
|||
*/
|
||||
. = ALIGN(32);
|
||||
__start___ex_table = .;
|
||||
#ifdef CONFIG_MMU
|
||||
*(__ex_table)
|
||||
#endif
|
||||
__stop___ex_table = .;
|
||||
|
||||
/*
|
||||
|
|
|
|||
|
|
@ -6,28 +6,31 @@
|
|||
|
||||
lib-y := backtrace.o changebit.o csumipv6.o csumpartial.o \
|
||||
csumpartialcopy.o csumpartialcopyuser.o clearbit.o \
|
||||
copy_page.o delay.o findbit.o memchr.o memcpy.o \
|
||||
delay.o findbit.o memchr.o memcpy.o \
|
||||
memmove.o memset.o memzero.o setbit.o \
|
||||
strncpy_from_user.o strnlen_user.o \
|
||||
strchr.o strrchr.o \
|
||||
testchangebit.o testclearbit.o testsetbit.o \
|
||||
getuser.o putuser.o clear_user.o \
|
||||
ashldi3.o ashrdi3.o lshrdi3.o muldi3.o \
|
||||
ucmpdi2.o lib1funcs.o div64.o sha1.o \
|
||||
io-readsb.o io-writesb.o io-readsl.o io-writesl.o
|
||||
|
||||
mmu-y := clear_user.o copy_page.o getuser.o putuser.o
|
||||
|
||||
# the code in uaccess.S is not preemption safe and
|
||||
# probably faster on ARMv3 only
|
||||
ifeq ($(CONFIG_PREEMPT),y)
|
||||
lib-y += copy_from_user.o copy_to_user.o
|
||||
mmu-y += copy_from_user.o copy_to_user.o
|
||||
else
|
||||
ifneq ($(CONFIG_CPU_32v3),y)
|
||||
lib-y += copy_from_user.o copy_to_user.o
|
||||
mmu-y += copy_from_user.o copy_to_user.o
|
||||
else
|
||||
lib-y += uaccess.o
|
||||
mmu-y += uaccess.o
|
||||
endif
|
||||
endif
|
||||
|
||||
lib-$(CONFIG_MMU) += $(mmu-y)
|
||||
|
||||
ifeq ($(CONFIG_CPU_32v3),y)
|
||||
lib-y += io-readsw-armv3.o io-writesw-armv3.o
|
||||
else
|
||||
|
|
|
|||
|
|
@ -40,16 +40,25 @@ struct exception_table_entry
|
|||
|
||||
extern int fixup_exception(struct pt_regs *regs);
|
||||
|
||||
/*
|
||||
* These two are intentionally not defined anywhere - if the kernel
|
||||
* code generates any references to them, that's a bug.
|
||||
*/
|
||||
extern int __get_user_bad(void);
|
||||
extern int __put_user_bad(void);
|
||||
|
||||
/*
|
||||
* Note that this is actually 0x1,0000,0000
|
||||
*/
|
||||
#define KERNEL_DS 0x00000000
|
||||
#define USER_DS TASK_SIZE
|
||||
|
||||
#define get_ds() (KERNEL_DS)
|
||||
|
||||
#ifdef CONFIG_MMU
|
||||
|
||||
#define USER_DS TASK_SIZE
|
||||
#define get_fs() (current_thread_info()->addr_limit)
|
||||
|
||||
static inline void set_fs (mm_segment_t fs)
|
||||
static inline void set_fs(mm_segment_t fs)
|
||||
{
|
||||
current_thread_info()->addr_limit = fs;
|
||||
modify_domain(DOMAIN_KERNEL, fs ? DOMAIN_CLIENT : DOMAIN_MANAGER);
|
||||
|
|
@ -75,8 +84,6 @@ static inline void set_fs (mm_segment_t fs)
|
|||
: "cc"); \
|
||||
flag; })
|
||||
|
||||
#define access_ok(type,addr,size) (__range_ok(addr,size) == 0)
|
||||
|
||||
/*
|
||||
* Single-value transfer routines. They automatically use the right
|
||||
* size if we just have the right pointer type. Note that the functions
|
||||
|
|
@ -87,20 +94,10 @@ static inline void set_fs (mm_segment_t fs)
|
|||
* fixup code, but there are a few places where it intrudes on the
|
||||
* main code path. When we only write to user space, there is no
|
||||
* problem.
|
||||
*
|
||||
* The "__xxx" versions of the user access functions do not verify the
|
||||
* address space - it must have been done previously with a separate
|
||||
* "access_ok()" call.
|
||||
*
|
||||
* The "xxx_error" versions set the third argument to EFAULT if an
|
||||
* error occurs, and leave it unchanged on success. Note that these
|
||||
* versions are void (ie, don't return a value as such).
|
||||
*/
|
||||
|
||||
extern int __get_user_1(void *);
|
||||
extern int __get_user_2(void *);
|
||||
extern int __get_user_4(void *);
|
||||
extern int __get_user_bad(void);
|
||||
|
||||
#define __get_user_x(__r2,__p,__e,__s,__i...) \
|
||||
__asm__ __volatile__ ( \
|
||||
|
|
@ -131,6 +128,74 @@ extern int __get_user_bad(void);
|
|||
__e; \
|
||||
})
|
||||
|
||||
extern int __put_user_1(void *, unsigned int);
|
||||
extern int __put_user_2(void *, unsigned int);
|
||||
extern int __put_user_4(void *, unsigned int);
|
||||
extern int __put_user_8(void *, unsigned long long);
|
||||
|
||||
#define __put_user_x(__r2,__p,__e,__s) \
|
||||
__asm__ __volatile__ ( \
|
||||
__asmeq("%0", "r0") __asmeq("%2", "r2") \
|
||||
"bl __put_user_" #__s \
|
||||
: "=&r" (__e) \
|
||||
: "0" (__p), "r" (__r2) \
|
||||
: "ip", "lr", "cc")
|
||||
|
||||
#define put_user(x,p) \
|
||||
({ \
|
||||
const register typeof(*(p)) __r2 asm("r2") = (x); \
|
||||
const register typeof(*(p)) __user *__p asm("r0") = (p);\
|
||||
register int __e asm("r0"); \
|
||||
switch (sizeof(*(__p))) { \
|
||||
case 1: \
|
||||
__put_user_x(__r2, __p, __e, 1); \
|
||||
break; \
|
||||
case 2: \
|
||||
__put_user_x(__r2, __p, __e, 2); \
|
||||
break; \
|
||||
case 4: \
|
||||
__put_user_x(__r2, __p, __e, 4); \
|
||||
break; \
|
||||
case 8: \
|
||||
__put_user_x(__r2, __p, __e, 8); \
|
||||
break; \
|
||||
default: __e = __put_user_bad(); break; \
|
||||
} \
|
||||
__e; \
|
||||
})
|
||||
|
||||
#else /* CONFIG_MMU */
|
||||
|
||||
/*
|
||||
* uClinux has only one addr space, so has simplified address limits.
|
||||
*/
|
||||
#define USER_DS KERNEL_DS
|
||||
|
||||
#define segment_eq(a,b) (1)
|
||||
#define __addr_ok(addr) (1)
|
||||
#define __range_ok(addr,size) (0)
|
||||
#define get_fs() (KERNEL_DS)
|
||||
|
||||
static inline void set_fs(mm_segment_t fs)
|
||||
{
|
||||
}
|
||||
|
||||
#define get_user(x,p) __get_user(x,p)
|
||||
#define put_user(x,p) __put_user(x,p)
|
||||
|
||||
#endif /* CONFIG_MMU */
|
||||
|
||||
#define access_ok(type,addr,size) (__range_ok(addr,size) == 0)
|
||||
|
||||
/*
|
||||
* The "__xxx" versions of the user access functions do not verify the
|
||||
* address space - it must have been done previously with a separate
|
||||
* "access_ok()" call.
|
||||
*
|
||||
* The "xxx_error" versions set the third argument to EFAULT if an
|
||||
* error occurs, and leave it unchanged on success. Note that these
|
||||
* versions are void (ie, don't return a value as such).
|
||||
*/
|
||||
#define __get_user(x,ptr) \
|
||||
({ \
|
||||
long __gu_err = 0; \
|
||||
|
|
@ -212,43 +277,6 @@ do { \
|
|||
: "r" (addr), "i" (-EFAULT) \
|
||||
: "cc")
|
||||
|
||||
extern int __put_user_1(void *, unsigned int);
|
||||
extern int __put_user_2(void *, unsigned int);
|
||||
extern int __put_user_4(void *, unsigned int);
|
||||
extern int __put_user_8(void *, unsigned long long);
|
||||
extern int __put_user_bad(void);
|
||||
|
||||
#define __put_user_x(__r2,__p,__e,__s) \
|
||||
__asm__ __volatile__ ( \
|
||||
__asmeq("%0", "r0") __asmeq("%2", "r2") \
|
||||
"bl __put_user_" #__s \
|
||||
: "=&r" (__e) \
|
||||
: "0" (__p), "r" (__r2) \
|
||||
: "ip", "lr", "cc")
|
||||
|
||||
#define put_user(x,p) \
|
||||
({ \
|
||||
const register typeof(*(p)) __r2 asm("r2") = (x); \
|
||||
const register typeof(*(p)) __user *__p asm("r0") = (p);\
|
||||
register int __e asm("r0"); \
|
||||
switch (sizeof(*(__p))) { \
|
||||
case 1: \
|
||||
__put_user_x(__r2, __p, __e, 1); \
|
||||
break; \
|
||||
case 2: \
|
||||
__put_user_x(__r2, __p, __e, 2); \
|
||||
break; \
|
||||
case 4: \
|
||||
__put_user_x(__r2, __p, __e, 4); \
|
||||
break; \
|
||||
case 8: \
|
||||
__put_user_x(__r2, __p, __e, 8); \
|
||||
break; \
|
||||
default: __e = __put_user_bad(); break; \
|
||||
} \
|
||||
__e; \
|
||||
})
|
||||
|
||||
#define __put_user(x,ptr) \
|
||||
({ \
|
||||
long __pu_err = 0; \
|
||||
|
|
@ -354,9 +382,16 @@ do { \
|
|||
: "cc")
|
||||
|
||||
|
||||
#ifdef CONFIG_MMU
|
||||
extern unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n);
|
||||
extern unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n);
|
||||
extern unsigned long __clear_user(void __user *addr, unsigned long n);
|
||||
#else
|
||||
#define __copy_from_user(to,from,n) (memcpy(to, (void __force *)from, n), 0)
|
||||
#define __copy_to_user(to,from,n) (memcpy((void __force *)to, from, n), 0)
|
||||
#define __clear_user(addr,n) (memset((void __force *)addr, 0, n), 0)
|
||||
#endif
|
||||
|
||||
extern unsigned long __strncpy_from_user(char *to, const char __user *from, unsigned long count);
|
||||
extern unsigned long __strnlen_user(const char __user *s, long n);
|
||||
|
||||
|
|
|
|||
Loading…
Reference in a new issue