diff options
Diffstat (limited to 'libc/sysdeps/linux/arc/clone.S')
| -rw-r--r-- | libc/sysdeps/linux/arc/clone.S | 36 |
1 files changed, 29 insertions, 7 deletions
diff --git a/libc/sysdeps/linux/arc/clone.S b/libc/sysdeps/linux/arc/clone.S index 9aa8d92cd..db5000caf 100644 --- a/libc/sysdeps/linux/arc/clone.S +++ b/libc/sysdeps/linux/arc/clone.S @@ -19,25 +19,32 @@ ; Current (Jul 2012) upstream powerpc/clone.S assumes similarly. ; Our LTP (from 2007) doesn't seem to have tests to prove otherwise -; clone syscall in kernel +; clone syscall in kernel (ABI: CONFIG_CLONE_BACKWARDS) ; -; int sys_clone(unsigned long clone_flags, unsigned long newsp, -; int __user *parent_tidptr, void *tls, +; int sys_clone(unsigned long clone_flags, +; unsigned long newsp, +; int __user *parent_tidptr, +; void *tls, ; int __user *child_tidptr) +#define CLONE_VM 0x00000100 +#define CLONE_THREAD 0x00010000 +#define CLONE_THREAD_N_VM (CLONE_THREAD | CLONE_VM) ENTRY(clone) cmp r0, 0 ; @fn can't be NULL cmp.ne r1, 0 ; @child_stack can't be NULL bz .L__sys_err - ; @fn and @args needed after the syscall for child - ; However r3 containing @arg will be clobbered BEFORE syscall + ; save some of the orig args ; r0 containg @fn will be clobbered AFTER syscall (with ret val) - mov r10, r0 - mov r11, r3 + ; rest are clobbered BEFORE syscall due to different arg ordering + mov r10, r0 ; @fn + mov r11, r3 ; @args + mov r12, r2 ; @clone_flags ; adjust libc args for syscall + mov r0, r2 ; libc @flags is 1st syscall arg mov r2, r4 ; libc @ptid mov r3, r5 ; libc @tls @@ -49,6 +56,21 @@ ENTRY(clone) blt .L__sys_err2 ; < 0 (signed) error jnz [blink] ; Parent returns + ; ----- child starts here --------- +#ifdef RESET_PID + mov_s r2, CLONE_THREAD_N_VM + and_s r2, r2, r12 + brne r2, r12, .Lgo_thread + + mov r8, __NR_clone + ARC_TRAP_INSN ; r0 has PID + THREAD_SELF r1 ; Get to struct pthread (just before TCB) + st r0, [r1, PTHREAD_PID] + st r0, [r1, PTHREAD_TID] + +.Lgo_thread: +#endif + ; child jumps off to @fn with @arg as argument, and returns here jl.d [r10] mov r0, r11 |