From: Stefan Liebler <stli@linux.ibm.com>
To: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>,
libc-alpha@sourceware.org
Subject: Re: [PATCH v2 1/4] s390x: Add the clone3 wrapper
Date: Thu, 13 Jul 2023 11:30:09 +0200 [thread overview]
Message-ID: <074639e3-5e12-d580-b64f-7798fcf5db6b@linux.ibm.com> (raw)
In-Reply-To: <a5d5809e-55a8-ef17-75ca-ca3dd00e67d0@linaro.org>
[-- Attachment #1: Type: text/plain, Size: 9533 bytes --]
Hi Adhemerval,
I had a further look into the implementation. And we can get rid of
save/restore of r6 to stack at all. Despite of r2 (return-value), the
syscall does not clobber the registers. Thus we can just keep func in r4
and arg in r5 and use both directly in thread_start.
Furthermore I've added a clone3.S in s390-32 directory and define
HAVE_CLONE3_WRAPPER to 1 for s390x(64bit)/s390(31bit).
The testsuite runs fine for both modes.
Both changes are within the patch-file attached (I'm not quite sure if
my mail-client corrupts an inlined patch).
Bye,
Stefan
On 12.07.23 20:08, Adhemerval Zanella Netto wrote:
>
>
> On 12/07/23 11:51, Stefan Liebler via Libc-alpha wrote:
>> Hi Adhemerval,
>>
>> I have applied your patches and tested it on s390x. I've ensured that
>> the wrapper is now used for pthread_create/posix_spawn and the testsuite
>> runs fine. Nevertheless I have some minor comments: see below.
>>
>> And one more question:
>> Is there a reason, why the wrapper is only added to s390x (64bit), but
>> not for s390 (31bit)? Should there be an #undef __ASSUME_CLONE3?
>> According to the kernel commit it is also available for compat-mode:
>> "s390: wire up clone3 system call"
>> https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?id=5518aed82d2abd97f8d3ec91d8ba455d939e8cd1
>
> Mainly because I could not test it properly: there is no easy access to
> s390x machine (such as on gcc build farm), there is no qemu-user support
> for 31-bit, and I saw strange results running s390 binaries on a s390x
> qemu vm.
>
>>
>> On 10.07.23 20:40, Adhemerval Zanella via Libc-alpha wrote:
>>> It follows the internal signature:
>>>
>>> extern int clone3 (struct clone_args *__cl_args, size_t __size,
>>> int (*__func) (void *__arg), void *__arg);
>>>
>>> Checked on s390x-linux-gnu.
>>> ---
>>> sysdeps/unix/sysv/linux/s390/s390-64/clone3.S | 81 +++++++++++++++++++
>>> sysdeps/unix/sysv/linux/s390/sysdep.h | 1 +
>>> 2 files changed, 82 insertions(+)
>>> create mode 100644 sysdeps/unix/sysv/linux/s390/s390-64/clone3.S
>>>
>>> diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/clone3.S b/sysdeps/unix/sysv/linux/s390/s390-64/clone3.S
>>> new file mode 100644
>>> index 0000000000..417fdcb785
>>> --- /dev/null
>>> +++ b/sysdeps/unix/sysv/linux/s390/s390-64/clone3.S
>>> @@ -0,0 +1,81 @@
>>> +/* The clone3 syscall wrapper. Linux/s390x version.
>>> + Copyright (C) 2023 Free Software Foundation, Inc.
>>> +
>>> + This file is part of the GNU C Library.
>>> +
>>> + The GNU C Library is free software; you can redistribute it and/or
>>> + modify it under the terms of the GNU Lesser General Public
>>> + License as published by the Free Software Foundation; either
>>> + version 2.1 of the License, or (at your option) any later version.
>>> +
>>> + The GNU C Library is distributed in the hope that it will be useful,
>>> + but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
>>> + Lesser General Public License for more details.
>>> +
>>> + You should have received a copy of the GNU Lesser General Public
>>> + License along with the GNU C Library; if not, see
>>> + <https://www.gnu.org/licenses/>. */
>>> +
>>> +#include <sysdep.h>
>>> +#define _ERRNO_H 1
>>> +#include <bits/errno.h>
>>> +
>>> +/* The userland implementation is:
>>> + int clone3 (struct clone_args *cl_args, size_t size,
>>> + int (*func)(void *arg), void *arg);
>>> +
>>> + the kernel entry is:
>>> + int clone3 (struct clone_args *cl_args, size_t size);
>>> +
>>> + The parameters are passed in registers from userland:
>>> + r2: cl_args
>>> + r3: size
>>> + r4: func
>>> + r5: arg */
>>> +
>>> + .text
>>> +ENTRY(__clone3)
>>> + stg %r6, 48(%r15)
>> Add cfi_offset (%r6,-112)
>>
>>
>>> +
>>> + /* Sanity check args. */
>>> + ltgr %r2, %r2
>>> + je error
>>> + ltgr %r6, %r4
>>> + je error
>>> +
>>> + /* Do the system call, the kernel expects:
>>> + r1: system call number
>>> + r2: cl_args
>>> + r3: size */
>>> + lghi %r1, SYS_ify(clone3)
>>> + svc 0
>>> + ltgr %r2,%r2 /* check return code */
>>> + jz thread_start
>>> + lg %r6, 48(%r15)
>>> + jgm SYSCALL_ERROR_LABEL
>>> + br %r14
>>> +error:
>>> + lghi %r2,-EINVAL
>>> + jg SYSCALL_ERROR_LABEL
>>> +PSEUDO_END (__clone3)
>>> +
>>> + .align 4
>> The ENTRY-macro from sysdep.h is using an alignment of 16 bytes. Can you
>> please also use it here?
>>
>>> + .type thread_start, %function
>>> +thread_start:
>>> + cfi_startproc
>>> + /* Mark r14 as undefined in order to stop unwinding here. */
>>> + cfi_undefined (r14)
>>> +
>>> + /* func is in gpr 6, arg in gpr 5. */
>>> + lgr %r2, %r5
>>> + aghi %r15, -160
>>> + xc 0(8,%r15),0(%r15)
>>> + basr %r14, %r6
>>> +
>>> + DO_CALL (exit, 1)
>>> + cfi_endproc
>>> + .size thread_start, .-thread_start
>> If you want, you can use ASM_SIZE_DIRECTIVE (thread_start) from sysdep.h
>> here, which is also used in END-macros.
>>> +
>>> +libc_hidden_def (__clone3)
>>> +weak_alias (__clone3, clone3)
>>> diff --git a/sysdeps/unix/sysv/linux/s390/sysdep.h b/sysdeps/unix/sysv/linux/s390/sysdep.h
>>> index 3bde8ba19c..b099fea9c6 100644
>>> --- a/sysdeps/unix/sysv/linux/s390/sysdep.h
>>> +++ b/sysdeps/unix/sysv/linux/s390/sysdep.h
>>> @@ -72,6 +72,7 @@
>>> #ifdef __s390x__
>>> #define HAVE_CLOCK_GETRES64_VSYSCALL "__kernel_clock_getres"
>>> #define HAVE_CLOCK_GETTIME64_VSYSCALL "__kernel_clock_gettime"
>>> +#define HAVE_CLONE3_WRAPPER 1
>>> #else
>>> #define HAVE_CLOCK_GETRES_VSYSCALL "__kernel_clock_getres"
>>> #define HAVE_CLOCK_GETTIME_VSYSCALL "__kernel_clock_gettime"
>
> Updated patch below.
>
> From 74f79943014c4df13f2ce6d6ccd60b8b271319b3 Mon Sep 17 00:00:00 2001
> From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
> Date: Tue, 27 Sep 2022 17:00:27 -0300
> Subject: [PATCH 1/9] s390x: Add the clone3 wrapper
>
> It follows the internal signature:
>
> extern int clone3 (struct clone_args *__cl_args, size_t __size,
> int (*__func) (void *__arg), void *__arg);
>
> Checked on s390x-linux-gnu.
> ---
> sysdeps/unix/sysv/linux/s390/s390-64/clone3.S | 82 +++++++++++++++++++
> sysdeps/unix/sysv/linux/s390/sysdep.h | 1 +
> 2 files changed, 83 insertions(+)
> create mode 100644 sysdeps/unix/sysv/linux/s390/s390-64/clone3.S
>
> diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/clone3.S b/sysdeps/unix/sysv/linux/s390/s390-64/clone3.S
> new file mode 100644
> index 0000000000..22e07fa450
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/s390/s390-64/clone3.S
> @@ -0,0 +1,82 @@
> +/* The clone3 syscall wrapper. Linux/s390x version.
> + Copyright (C) 2023 Free Software Foundation, Inc.
> +
> + This file is part of the GNU C Library.
> +
> + The GNU C Library is free software; you can redistribute it and/or
> + modify it under the terms of the GNU Lesser General Public
> + License as published by the Free Software Foundation; either
> + version 2.1 of the License, or (at your option) any later version.
> +
> + The GNU C Library is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + Lesser General Public License for more details.
> +
> + You should have received a copy of the GNU Lesser General Public
> + License along with the GNU C Library; if not, see
> + <https://www.gnu.org/licenses/>. */
> +
> +#include <sysdep.h>
> +#define _ERRNO_H 1
> +#include <bits/errno.h>
> +
> +/* The userland implementation is:
> + int clone3 (struct clone_args *cl_args, size_t size,
> + int (*func)(void *arg), void *arg);
> +
> + the kernel entry is:
> + int clone3 (struct clone_args *cl_args, size_t size);
> +
> + The parameters are passed in registers from userland:
> + r2: cl_args
> + r3: size
> + r4: func
> + r5: arg */
> +
> + .text
> +ENTRY(__clone3)
> + stg %r6, 48(%r15)
> + cfi_offset (%r6, -112)
> +
> + /* Sanity check args. */
> + ltgr %r2, %r2
> + je error
> + ltgr %r6, %r4
> + je error
> +
> + /* Do the system call, the kernel expects:
> + r1: system call number
> + r2: cl_args
> + r3: size */
> + lghi %r1, SYS_ify(clone3)
> + svc 0
> + ltgr %r2,%r2 /* check return code */
> + jz thread_start
> + lg %r6, 48(%r15)
> + jgm SYSCALL_ERROR_LABEL
> + br %r14
> +error:
> + lghi %r2,-EINVAL
> + jg SYSCALL_ERROR_LABEL
> +PSEUDO_END (__clone3)
> +
> + .align 16
> + .type thread_start, %function
> +thread_start:
> + cfi_startproc
> + /* Mark r14 as undefined in order to stop unwinding here. */
> + cfi_undefined (r14)
> +
> + /* func is in gpr 6, arg in gpr 5. */
> + lgr %r2, %r5
> + aghi %r15, -160
> + xc 0(8,%r15),0(%r15)
> + basr %r14, %r6
> +
> + DO_CALL (exit, 1)
> + cfi_endproc
> + ASM_SIZE_DIRECTIVE (thread_start)
> +
> +libc_hidden_def (__clone3)
> +weak_alias (__clone3, clone3)
> diff --git a/sysdeps/unix/sysv/linux/s390/sysdep.h b/sysdeps/unix/sysv/linux/s390/sysdep.h
> index 3bde8ba19c..b099fea9c6 100644
> --- a/sysdeps/unix/sysv/linux/s390/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/s390/sysdep.h
> @@ -72,6 +72,7 @@
> #ifdef __s390x__
> #define HAVE_CLOCK_GETRES64_VSYSCALL "__kernel_clock_getres"
> #define HAVE_CLOCK_GETTIME64_VSYSCALL "__kernel_clock_gettime"
> +#define HAVE_CLONE3_WRAPPER 1
> #else
> #define HAVE_CLOCK_GETRES_VSYSCALL "__kernel_clock_getres"
> #define HAVE_CLOCK_GETTIME_VSYSCALL "__kernel_clock_gettime"
[-- Attachment #2: 20230713_az_clone3.patch --]
[-- Type: text/x-patch, Size: 5490 bytes --]
commit 7da61096ec02165454aeaa7436fbe3ccb20b695c
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date: Mon Jul 10 15:40:19 2023 -0300
s390x: Add the clone3 wrapper
It follows the internal signature:
extern int clone3 (struct clone_args *__cl_args, size_t __size,
int (*__func) (void *__arg), void *__arg);
Checked on s390x-linux-gnu.
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/clone3.S b/sysdeps/unix/sysv/linux/s390/s390-32/clone3.S
new file mode 100644
index 0000000000..bbe75ce893
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/s390/s390-32/clone3.S
@@ -0,0 +1,78 @@
+/* The clone3 syscall wrapper. Linux/s390x version.
+ Copyright (C) 2023 Free Software Foundation, Inc.
+
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <sysdep.h>
+#define _ERRNO_H 1
+#include <bits/errno.h>
+
+/* The userland implementation is:
+ int clone3 (struct clone_args *cl_args, size_t size,
+ int (*func)(void *arg), void *arg);
+
+ the kernel entry is:
+ int clone3 (struct clone_args *cl_args, size_t size);
+
+ The parameters are passed in registers from userland:
+ r2: cl_args
+ r3: size
+ r4: func
+ r5: arg */
+
+ .text
+ENTRY(__clone3)
+ /* Sanity check args. */
+ ltr %r2, %r2
+ je error
+ ltr %r4, %r4
+ je error
+
+ /* Do the system call, the kernel expects:
+ r1: system call number
+ r2: cl_args
+ r3: size */
+ lhi %r1, SYS_ify(clone3)
+ svc 0
+ ltr %r2,%r2 /* check return code */
+ jz thread_start
+ jm SYSCALL_ERROR_LABEL
+ br %r14
+error:
+ lhi %r2,-EINVAL
+ j SYSCALL_ERROR_LABEL
+PSEUDO_END (__clone3)
+
+ .align 16
+ .type thread_start, %function
+thread_start:
+ cfi_startproc
+ /* Mark r14 as undefined in order to stop unwinding here. */
+ cfi_undefined (r14)
+
+ /* func is in gpr 4, arg in gpr 5. */
+ lr %r2, %r5
+ ahi %r15, -96
+ xc 0(4,%r15),0(%r15)
+ basr %r14, %r4
+
+ DO_CALL (exit, 1)
+ cfi_endproc
+ ASM_SIZE_DIRECTIVE (thread_start)
+
+libc_hidden_def (__clone3)
+weak_alias (__clone3, clone3)
diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/clone3.S b/sysdeps/unix/sysv/linux/s390/s390-64/clone3.S
new file mode 100644
index 0000000000..62800f8ef3
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/clone3.S
@@ -0,0 +1,78 @@
+/* The clone3 syscall wrapper. Linux/s390x version.
+ Copyright (C) 2023 Free Software Foundation, Inc.
+
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <sysdep.h>
+#define _ERRNO_H 1
+#include <bits/errno.h>
+
+/* The userland implementation is:
+ int clone3 (struct clone_args *cl_args, size_t size,
+ int (*func)(void *arg), void *arg);
+
+ the kernel entry is:
+ int clone3 (struct clone_args *cl_args, size_t size);
+
+ The parameters are passed in registers from userland:
+ r2: cl_args
+ r3: size
+ r4: func
+ r5: arg */
+
+ .text
+ENTRY(__clone3)
+ /* Sanity check args. */
+ ltgr %r2, %r2
+ je error
+ ltgr %r4, %r4
+ je error
+
+ /* Do the system call, the kernel expects:
+ r1: system call number
+ r2: cl_args
+ r3: size */
+ lghi %r1, SYS_ify(clone3)
+ svc 0
+ ltgr %r2,%r2 /* check return code */
+ jz thread_start
+ jgm SYSCALL_ERROR_LABEL
+ br %r14
+error:
+ lghi %r2,-EINVAL
+ jg SYSCALL_ERROR_LABEL
+PSEUDO_END (__clone3)
+
+ .align 16
+ .type thread_start, %function
+thread_start:
+ cfi_startproc
+ /* Mark r14 as undefined in order to stop unwinding here. */
+ cfi_undefined (r14)
+
+ /* func is in gpr 4, arg in gpr 5. */
+ lgr %r2, %r5
+ aghi %r15, -160
+ xc 0(8,%r15),0(%r15)
+ basr %r14, %r4
+
+ DO_CALL (exit, 1)
+ cfi_endproc
+ ASM_SIZE_DIRECTIVE (thread_start)
+
+libc_hidden_def (__clone3)
+weak_alias (__clone3, clone3)
diff --git a/sysdeps/unix/sysv/linux/s390/sysdep.h b/sysdeps/unix/sysv/linux/s390/sysdep.h
index 3bde8ba19c..b2621630f0 100644
--- a/sysdeps/unix/sysv/linux/s390/sysdep.h
+++ b/sysdeps/unix/sysv/linux/s390/sysdep.h
@@ -79,4 +79,5 @@
#define HAVE_GETTIMEOFDAY_VSYSCALL "__kernel_gettimeofday"
#define HAVE_GETCPU_VSYSCALL "__kernel_getcpu"
+#define HAVE_CLONE3_WRAPPER 1
#endif
next prev parent reply other threads:[~2023-07-13 9:30 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-10 18:40 [PATCH v2 0/4] Add clone3 support for multiple architectures Adhemerval Zanella
2023-07-10 18:40 ` [PATCH v2 1/4] s390x: Add the clone3 wrapper Adhemerval Zanella
2023-07-12 14:51 ` Stefan Liebler
2023-07-12 18:08 ` Adhemerval Zanella Netto
2023-07-13 9:30 ` Stefan Liebler [this message]
2023-07-13 11:52 ` Adhemerval Zanella Netto
2023-07-10 18:40 ` [PATCH v2 2/4] arm: " Adhemerval Zanella
2023-07-10 18:40 ` [PATCH v2 3/4] mips: " Adhemerval Zanella
2023-07-10 18:40 ` [PATCH v2 4/4] linux: Undef __ASSUME_CLONE3 for alpha, ia64, nios2, sh, and sparc Adhemerval Zanella
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=074639e3-5e12-d580-b64f-7798fcf5db6b@linux.ibm.com \
--to=stli@linux.ibm.com \
--cc=adhemerval.zanella@linaro.org \
--cc=libc-alpha@sourceware.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).