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ARM: user_memcpy/memset/strlcpy: fix my horrible ARM assembly

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Turns out I was way to green (and tired) last year to code this properly...
now they finally work and the kernel is a lot more stable for it.
This commit is contained in:
Ithamar R. Adema 2013-09-18 21:55:37 +02:00
parent 31e17f9d7b
commit 1847d8c486
1 changed files with 28 additions and 26 deletions
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54
src/system/kernel/arch/arm/arch_asm.S
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@ -82,27 +82,32 @@ FUNCTION(arm_context_switch):
bx lr
FUNCTION_END(arm_context_switch)
/* addr_t arm_get_fsr(void); */
FUNCTION(arm_get_fsr):
mrc p15, 0, r0, c5, c0, 0 @ get FSR
bx lr
FUNCTION_END(arm_get_fsr)
/* addr_t arm_get_far(void); */
FUNCTION(arm_get_far):
mrc p15, 0, r0, c6, c0, 0 @ get FAR
bx lr
FUNCTION_END(arm_get_far)
/* addr_t arm_get_fp(void); */
FUNCTION(arm_get_fp):
mov r0, fp @ get framepointer
bx lr
FUNCTION_END(arm_get_fp);
/* status_t arch_cpu_user_memcpy(void *to, const void *from, size_t size, addr_t *faultHandler) */
FUNCTION(arch_cpu_user_memcpy):
stmfd sp!, { r4-r6 }
stmfd sp!, { r4-r6, lr }
ldr r6, [r3]
ldr r4, =.L_user_memcpy_error
str r4, [r3] /* set fault handler */
@ -112,33 +117,35 @@ FUNCTION(arch_cpu_user_memcpy):
str r5, [r0]
add r1, #4
add r0, #4
sub r4, #1
subs r4, #1
bne 1b
ands r4, r2, #3 /* size % 4 */
beq 3f
2:
and r4, r2, #3 /* size % 4 */
ldrb r5, [r1]
strb r5, [r0]
add r1, #1
add r0, #1
sub r4, #1
subs r4, #1
bne 2b
3:
str r6, [r3] /* restore fault handler */
mov r0, #0
ldmfd sp!, { r4-r6 }
bx lr
ldmfd sp!, { r4-r6, pc }
.L_user_memcpy_error:
str r6, [r3] /* restore fault handler */
mov r0, #-1
ldmfd sp!, { r4-r6 }
bx lr
ldmfd sp!, { r4-r6, pc }
FUNCTION_END(arch_cpu_user_memcpy)
/* status_t arch_cpu_user_memset(void *to, char c, size_t count, addr_t *faultHandler) */
FUNCTION(arch_cpu_user_memset):
stmfd sp!, { r4-r5 }
stmfd sp!, { r4-r5, lr }
ldr r5, [r3]
ldr r4, =.L_user_memset_error
str r4, [r3]
@ -152,33 +159,31 @@ FUNCTION(arch_cpu_user_memset):
1:
str r1, [r0]
add r0, r0, #4
sub r4, r4, #1
subs r4, r4, #1
bne 1b
and r4, r2, #3 /* count % 4 */
2:
strb r1, [r0]
add r0, r0, #1
sub r4, r4, #1
subs r4, r4, #1
bne 2b
mov r0, #0
str r5, [r3]
ldmfd sp!, { r4-r5 }
bx lr
ldmfd sp!, { r4-r5, pc }
.L_user_memset_error:
mov r0, #-1
str r5, [r3]
ldmfd sp!, { r4-r5 }
bx lr
ldmfd sp!, { r4-r5, pc }
FUNCTION_END(arch_cpu_user_memset)
/* ssize_t arch_cpu_user_strlcpy(void *to, const void *from, size_t size, addr_t *faultHandler) */
FUNCTION(arch_cpu_user_strlcpy):
stmfd sp!, { r4-r6 }
stmfd sp!, { r4-r6, lr }
ldr r5, [r3]
ldr r4, =.L_user_strlcpy_error
str r4, [r3]
@ -187,7 +192,7 @@ FUNCTION(arch_cpu_user_strlcpy):
ldrb r4, [r1, r6]
strb r4, [r0, r6]
add r6, r6, #1
and r4, #0xff /* done yet? */
cmp r4, #0
beq 2f
cmp r6, r2 /* reached max length? */
blt 1b
@ -195,18 +200,16 @@ FUNCTION(arch_cpu_user_strlcpy):
mov r4, #0
strb r4, [r0, r6]
mov r0, r4 /* return B_OK */
mov r0, r6 /* return length */
str r5, [r3] /* restore fault handler */
ldmfd sp!, { r4-r6 }
bx lr
ldmfd sp!, { r4-r6, pc }
.L_user_strlcpy_error:
mov r0, #-1
str r5, [r3]
ldmfd sp!, { r4-r6 }
bx lr
ldmfd sp!, { r4-r6, pc }
FUNCTION_END(arch_cpu_user_strlcpy)
@ -242,12 +245,11 @@ FUNCTION(arch_debug_call_with_fault_handler):
blx r2
// regular return
ldmfd sp!, { r4, lr }
bx lr
ldmfd sp!, { r4, pc }
// fault -- return via longjmp(jumpBuffer, 1)
1:
mov r0, r4
mov r0, r1
mov r1, #1
bl longjmp
FUNCTION_END(arch_debug_call_with_fault_handler)