From: Andy Lutomirski <luto@amacapital.net>
To: Josh Triplett <josh@joshtriplett.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>,
Andrew Morton <akpm@linux-foundation.org>,
Ingo Molnar <mingo@redhat.com>, Kees Cook <keescook@chromium.org>,
Oleg Nesterov <oleg@redhat.com>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
"H. Peter Anvin" <hpa@zytor.com>, Rik van Riel <riel@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Thiago Macieira <thiago.macieira@intel.com>,
Michael Kerrisk <mtk.manpages@gmail.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Linux API <linux-api@vger.kernel.org>,
Linux FS Devel <linux-fsdevel@vger.kernel.org>,
X86 ML <x86@kernel.org>
Subject: Re: [PATCH 2/6] x86: Opt into HAVE_COPY_THREAD_TLS, for both 32-bit and 64-bit
Date: Fri, 13 Mar 2015 15:01:16 -0700 [thread overview]
Message-ID: <CALCETrUbQJhE8VCTt5yQ+KBZOJnNC5e3yUneKjhwhKxgvfU2Xg@mail.gmail.com> (raw)
In-Reply-To: <cf79b9f0c40314e6bfda7c634e378015bd7ba037.1426180120.git.josh@joshtriplett.org>
On Thu, Mar 12, 2015 at 6:40 PM, Josh Triplett <josh@joshtriplett.org> wrote:
> For 32-bit userspace on a 64-bit kernel, this requires modifying
> stub32_clone to actually swap the appropriate arguments to match
> CONFIG_CLONE_BACKWARDS, rather than just leaving the C argument for tls
> broken.
>
> Signed-off-by: Josh Triplett <josh@joshtriplett.org>
> Signed-off-by: Thiago Macieira <thiago.macieira@intel.com>
> ---
> arch/x86/Kconfig | 1 +
> arch/x86/ia32/ia32entry.S | 2 +-
> arch/x86/kernel/process_32.c | 6 +++---
> arch/x86/kernel/process_64.c | 8 ++++----
> 4 files changed, 9 insertions(+), 8 deletions(-)
>
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index b7d31ca..4960b0d 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -124,6 +124,7 @@ config X86
> select MODULES_USE_ELF_REL if X86_32
> select MODULES_USE_ELF_RELA if X86_64
> select CLONE_BACKWARDS if X86_32
> + select HAVE_COPY_THREAD_TLS
> select ARCH_USE_BUILTIN_BSWAP
> select ARCH_USE_QUEUE_RWLOCK
> select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
> diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S
> index 156ebca..0286735 100644
> --- a/arch/x86/ia32/ia32entry.S
> +++ b/arch/x86/ia32/ia32entry.S
> @@ -487,7 +487,7 @@ GLOBAL(\label)
> ALIGN
> GLOBAL(stub32_clone)
> leaq sys_clone(%rip),%rax
> - mov %r8, %rcx
> + xchg %r8, %rcx
> jmp ia32_ptregs_common
Do I understand correct that whatever function this is a stub for just
takes its arguments in the wrong order? If so, can we just fix it
instead of using xchg here?
In general, I much prefer C code to new asm where it makes sense to
make this tradeoff.
Other than that, this is a huge improvement. You'll have minor
conflicts against -tip, though.
--Andy
next prev parent reply other threads:[~2015-03-13 22:01 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-13 1:40 [PATCH 0/6] CLONE_FD: Task exit notification via file descriptor Josh Triplett
2015-03-13 1:40 ` [PATCH 1/6] clone: Support passing tls argument via C rather than pt_regs magic Josh Triplett
2015-03-13 1:40 ` [PATCH 2/6] x86: Opt into HAVE_COPY_THREAD_TLS, for both 32-bit and 64-bit Josh Triplett
2015-03-13 22:01 ` Andy Lutomirski [this message]
2015-03-13 22:31 ` josh
2015-03-13 22:38 ` Andy Lutomirski
2015-03-13 22:43 ` josh
2015-03-13 22:45 ` Andy Lutomirski
2015-03-13 23:01 ` josh
2015-03-13 1:40 ` [PATCH 3/6] Introduce a new clone4 syscall with more flag bits and extensible arguments Josh Triplett
2015-03-13 1:40 ` [PATCH 4/6] signal: Factor out a helper function to process task_struct exit_code Josh Triplett
2015-03-13 1:40 ` [PATCH 5/6] fs: Make alloc_fd non-private Josh Triplett
2015-03-13 1:41 ` [PATCH 6/6] clone4: Introduce new CLONE_FD flag to get task exit notification via fd Josh Triplett
2015-03-13 16:21 ` Oleg Nesterov
2015-03-13 19:57 ` josh
2015-03-13 21:34 ` Andy Lutomirski
2015-03-13 22:20 ` josh
2015-03-13 22:28 ` Andy Lutomirski
2015-03-13 22:34 ` josh
2015-03-13 22:38 ` Andy Lutomirski
2015-03-14 14:14 ` Oleg Nesterov
2015-03-14 14:32 ` Oleg Nesterov
2015-03-14 18:38 ` Thiago Macieira
2015-03-14 18:54 ` Oleg Nesterov
2015-03-14 22:03 ` Josh Triplett
2015-03-14 22:26 ` Thiago Macieira
2015-03-14 19:01 ` Josh Triplett
2015-03-14 19:18 ` Oleg Nesterov
2015-03-14 19:47 ` Oleg Nesterov
2015-03-14 20:14 ` Josh Triplett
2015-03-14 20:30 ` Oleg Nesterov
2015-03-14 22:14 ` Josh Triplett
2015-03-14 20:03 ` Josh Triplett
2015-03-14 20:20 ` Oleg Nesterov
2015-03-14 22:09 ` Josh Triplett
2015-03-14 14:35 ` Oleg Nesterov
2015-03-14 19:15 ` Josh Triplett
2015-03-14 19:24 ` Oleg Nesterov
2015-03-14 19:48 ` Josh Triplett
2015-03-13 1:41 ` [PATCH] clone4.2: New manpage documenting clone4(2) Josh Triplett
2015-03-13 2:07 ` [PATCH 0/6] CLONE_FD: Task exit notification via file descriptor Thiago Macieira
2015-03-13 16:05 ` David Drysdale
2015-03-13 19:42 ` Josh Triplett
2015-03-13 21:16 ` Thiago Macieira
2015-03-13 21:44 ` josh
2015-03-13 21:33 ` Andy Lutomirski
2015-03-13 21:45 ` josh
2015-03-13 21:51 ` Andy Lutomirski
2015-03-14 1:11 ` Thiago Macieira
2015-03-14 19:03 ` Thiago Macieira
2015-03-14 19:29 ` Josh Triplett
2015-03-15 10:18 ` David Drysdale
2015-03-15 10:59 ` Josh Triplett
2015-03-15 8:55 ` David Drysdale
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=CALCETrUbQJhE8VCTt5yQ+KBZOJnNC5e3yUneKjhwhKxgvfU2Xg@mail.gmail.com \
--to=luto@amacapital.net \
--cc=akpm@linux-foundation.org \
--cc=hpa@zytor.com \
--cc=josh@joshtriplett.org \
--cc=keescook@chromium.org \
--cc=linux-api@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=mtk.manpages@gmail.com \
--cc=oleg@redhat.com \
--cc=paulmck@linux.vnet.ibm.com \
--cc=riel@redhat.com \
--cc=tglx@linutronix.de \
--cc=thiago.macieira@intel.com \
--cc=viro@zeniv.linux.org.uk \
--cc=x86@kernel.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 NNTP newsgroup(s).