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>

diff --git a/sysdeps/unix/sysv/linux/arc/clone.S b/sysdeps/unix/sysv/linux/arc/clone.S
index 76664962565809671c0210dd01ca9a27d92021c4..0029aaeb817035f89331de55bb5acf16bc8e67a5 100644 (file)
--- a/sysdeps/unix/sysv/linux/arc/clone.S
+++ b/sysdeps/unix/sysv/linux/arc/clone.S
@@ -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)