[klibc] ARM: fix EABI and Thumb versions of vfork()
For EABI and Thumb, the system call number is in r7, which is a
saved register; we need to save r7 into a clobbered register (using r3)
around the system call.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/usr/klibc/arch/arm/vfork.S b/usr/klibc/arch/arm/vfork.S
index 42e8551..1c39bd6 100644
--- a/usr/klibc/arch/arm/vfork.S
+++ b/usr/klibc/arch/arm/vfork.S
@@ -9,11 +9,17 @@
.type vfork,#function
.globl vfork
#ifndef __thumb__
- /* ARM version - this is executed after the swi */
.balign 4
vfork:
+#ifdef __ARM_EABI__
+ mov r3, r7
+ mov r7, # __NR_vfork
+ swi 0
+ mov r7, r3
+#else
swi # __NR_vfork
+#endif
cmn r0, #4096
rsbcs r2, r0, #0
ldrcs r3, 1f
@@ -26,13 +32,14 @@
.word errno
#else
- /* Thumb version - must still load r4 and r5 and run swi */
.thumb_func
.balign 2
vfork:
+ mov r3, r7
mov r7, # __NR_vfork
swi 0
+ mov r7, r3
ldr r1, 2f
cmp r0, r1
bcc 1f
