From: Pavel.Kozlov@synopsys.com
To: libc-alpha@sourceware.org
Cc: linux-snps-arc@lists.infradead.org,
Pavel Kozlov <Pavel.Kozlov@synopsys.com>
Subject: [PATCH 2/2] ARC: run child from the separate start block in __clone
Date: Thu, 2 Mar 2023 20:10:19 +0400 [thread overview]
Message-ID: <20230302161019.27192-2-kozlov@synopsys.com> (raw)
In-Reply-To: <20230302161019.27192-1-kozlov@synopsys.com>
From: Pavel Kozlov <pavel.kozlov@synopsys.com>
For better debug experience use separate code block with extra
cfi_* directives to run child (same as in __clone3).
---
sysdeps/unix/sysv/linux/arc/clone.S | 40 ++++++++++++++++++-----------
1 file changed, 25 insertions(+), 15 deletions(-)
diff --git a/sysdeps/unix/sysv/linux/arc/clone.S b/sysdeps/unix/sysv/linux/arc/clone.S
index 766649625658..0029aaeb8170 100644
--- 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)
--
2.25.1
next prev parent reply other threads:[~2023-03-02 16:12 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-02 16:10 [PATCH 1/2] ARC: Add the clone3 wrapper Pavel.Kozlov
2023-03-02 16:10 ` Pavel.Kozlov [this message]
2023-03-07 12:03 ` [PATCH 2/2] ARC: run child from the separate start block in __clone Adhemerval Zanella Netto
2023-03-07 12:02 ` [PATCH 1/2] ARC: Add the clone3 wrapper Adhemerval Zanella Netto
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