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From: Ingo Molnar <mingo@kernel.org>
To: Andy Lutomirski <luto@amacapital.net>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
	Denys Vlasenko <dvlasenk@redhat.com>,
	Borislav Petkov <bp@alien8.de>
Subject: Re: [PATCH 1/3] x86_64, entry: Remove a bogus ret_from_fork optimization
Date: Wed, 25 Feb 2015 08:23:28 +0100	[thread overview]
Message-ID: <20150225072328.GB13061@gmail.com> (raw)
In-Reply-To: <1b78c9e7b89e1c9481cd096fe57c2fb653eb9679.1424822291.git.luto@amacapital.net>


* Andy Lutomirski <luto@amacapital.net> wrote:

> ret_from_fork checks TIF_IA32 to determine whether pt_regs and the
> related state make sense for ret_from_sys_call.  This is entirely
> the wrong check.  TS_COMPAT would make a little more sense, but
> there's really no point in keeping this optimization at all.
> 
> This fixes a return to the wrong user CS if we came from int 0x80 in
> a 64-bit task.
> 
> Signed-off-by: Andy Lutomirski <luto@amacapital.net>

Acked-by: Ingo Molnar <mingo@kernel.org>

Thanks,

	Ingo

  reply	other threads:[~2015-02-25  7:23 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-02-25  0:01 [PATCH 0/3] Some TIF_IA32 fixes Andy Lutomirski
2015-02-25  0:01 ` [PATCH 1/3] x86_64, entry: Remove a bogus ret_from_fork optimization Andy Lutomirski
2015-02-25  7:23   ` Ingo Molnar [this message]
2015-02-25  0:01 ` [PATCH 2/3] x86_64, ptrace: Remove checks for TIF_IA32 when changing cs and ss Andy Lutomirski
2015-02-25  8:27   ` [tip:x86/asm] x86/ptrace: Remove checks for TIF_IA32 when changing CS and SS tip-bot for Andy Lutomirski
2015-02-25  0:01 ` [PATCH 3/3] x86_64, copy_thread: Fix CLONE_SETTLS bitness Andy Lutomirski
2015-02-25  8:27   ` [tip:x86/asm] x86/ia32-compat: Fix CLONE_SETTLS bitness of copy_thread() tip-bot for Andy Lutomirski

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