ARC: run child from the separate start block in __clone

For better debug experience use separate code block with extra
cfi_* directives to run child (same as in __clone3).

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
This commit is contained in:
Pavel Kozlov 2023-03-02 20:10:19 +04:00
parent 3681cdb8f8
commit 447273e0bf

View File

@ -20,9 +20,6 @@
#include <sysdep.h>
#define _ERRNO_H 1
#include <bits/errno.h>
#include <tcb-offsets.h>
#define CLONE_SETTLS 0x00080000
/* int clone(int (*fn)(void *), void *child_stack,
int flags, void *arg, ...
@ -63,19 +60,9 @@ ENTRY (__clone)
ARC_TRAP_INSN
cmp r0, 0 /* return code : 0 new process, !0 parent. */
beq thread_start_clone
blt L (__sys_err2) /* < 0 (signed) error. */
jnz [blink] /* Parent returns. */
/* child jumps off to @fn with @arg as argument
TP register already set by kernel. */
jl.d [r10]
mov r0, r11
/* exit() with result from @fn (already in r0). */
mov r8, __NR_exit
ARC_TRAP_INSN
/* In case it ever came back. */
flag 1
j [blink] /* Parent returns. */
L (__sys_err):
mov r0, -EINVAL
@ -89,5 +76,28 @@ L (__sys_err2):
position independent. */
b __syscall_error
PSEUDO_END (__clone)
.align 4
.type thread_start_clone, %function
thread_start_clone:
cfi_startproc
/* Terminate call stack by noting ra is undefined. */
cfi_undefined (blink)
/* Child jumps off to @fn with @arg as argument. */
jl.d [r10]
mov r0, r11
/* exit() with result from @fn (already in r0). */
mov r8, __NR_exit
ARC_TRAP_INSN
/* In case it ever came back. */
flag 1
cfi_endproc
.size thread_start_clone, .-thread_start_clone
libc_hidden_def (__clone)
weak_alias (__clone, clone)