From: Andreas Schwab <schwab@linux-m68k.org>
To: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Paul Mackerras <paulus@samba.org>,
linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/3] powerpc/uaccess: Switch __put_user_size_allowed() to __put_user_asm_goto()
Date: Wed, 28 Oct 2020 00:26:16 +0100 [thread overview]
Message-ID: <87mu079ron.fsf@igel.home> (raw)
In-Reply-To: <94ba5a5138f99522e1562dbcdb38d31aa790dc89.1599216721.git.christophe.leroy__44535.5968013004$1599217383$gmane$org@csgroup.eu> (Christophe Leroy's message of "Fri, 4 Sep 2020 11:01:30 +0000 (UTC)")
On Sep 04 2020, Christophe Leroy wrote:
> __put_user_asm_goto() provides more flexibility to GCC and avoids using
> a local variable to tell if the write succeeded or not.
> GCC can then avoid implementing a cmp in the fast path.
That breaks CLONE_CHILD_SETTID. I'm getting an assertion failure in
__libc_fork (THREAD_GETMEM (self, tid) != ppid).
Andreas.
--
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1
"And now for something completely different."
WARNING: multiple messages have this Message-ID (diff)
From: Andreas Schwab <schwab@linux-m68k.org>
To: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>,
linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/3] powerpc/uaccess: Switch __put_user_size_allowed() to __put_user_asm_goto()
Date: Wed, 28 Oct 2020 00:26:16 +0100 [thread overview]
Message-ID: <87mu079ron.fsf@igel.home> (raw)
In-Reply-To: <94ba5a5138f99522e1562dbcdb38d31aa790dc89.1599216721.git.christophe.leroy__44535.5968013004$1599217383$gmane$org@csgroup.eu> (Christophe Leroy's message of "Fri, 4 Sep 2020 11:01:30 +0000 (UTC)")
On Sep 04 2020, Christophe Leroy wrote:
> __put_user_asm_goto() provides more flexibility to GCC and avoids using
> a local variable to tell if the write succeeded or not.
> GCC can then avoid implementing a cmp in the fast path.
That breaks CLONE_CHILD_SETTID. I'm getting an assertion failure in
__libc_fork (THREAD_GETMEM (self, tid) != ppid).
Andreas.
--
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1
"And now for something completely different."
next parent reply other threads:[~2020-10-27 23:35 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <94ba5a5138f99522e1562dbcdb38d31aa790dc89.1599216721.git.christophe.leroy__44535.5968013004$1599217383$gmane$org@csgroup.eu>
2020-10-27 23:26 ` Andreas Schwab [this message]
2020-10-27 23:26 ` [PATCH 1/3] powerpc/uaccess: Switch __put_user_size_allowed() to __put_user_asm_goto() Andreas Schwab
2020-10-27 23:37 ` Andreas Schwab
2020-10-27 23:37 ` Andreas Schwab
2020-10-28 5:19 ` Michael Ellerman
2020-10-28 5:19 ` Michael Ellerman
2020-10-28 7:59 ` Andreas Schwab
2020-10-28 7:59 ` Andreas Schwab
2020-10-29 20:29 ` Andreas Schwab
2020-10-29 20:29 ` Andreas Schwab
2020-11-03 13:21 ` Michael Ellerman
2020-11-03 13:21 ` Michael Ellerman
2020-09-04 11:01 Christophe Leroy
2020-09-04 11:01 ` Christophe Leroy
2020-09-17 11:27 ` Michael Ellerman
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