From: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> To: Qiaowei Ren <qiaowei.ren@intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com>, Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, Dave Hansen <dave.hansen@intel.com>, x86@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v8 08/10] x86, mpx: add prctl commands PR_MPX_REGISTER, PR_MPX_UNREGISTER Date: Mon, 15 Sep 2014 01:00:25 +0100 [thread overview] Message-ID: <20140915010025.5940c946@alan.etchedpixels.co.uk> (raw) In-Reply-To: <1410425210-24789-9-git-send-email-qiaowei.ren@intel.com> > The base of the bounds directory is set into mm_struct during > PR_MPX_REGISTER command execution. This member can be used to > check whether one application is mpx enabled. Not really because by the time you ask the question another thread might have decided to unregister it. > +int mpx_register(struct task_struct *tsk) > +{ > + struct mm_struct *mm = tsk->mm; > + > + if (!cpu_has_mpx) > + return -EINVAL; > + > + /* > + * runtime in the userspace will be responsible for allocation of > + * the bounds directory. Then, it will save the base of the bounds > + * directory into XSAVE/XRSTOR Save Area and enable MPX through > + * XRSTOR instruction. > + * > + * fpu_xsave() is expected to be very expensive. In order to do > + * performance optimization, here we get the base of the bounds > + * directory and then save it into mm_struct to be used in future. > + */ > + mm->bd_addr = task_get_bounds_dir(tsk); > + if (!mm->bd_addr) > + return -EINVAL; What stops two threads calling this in parallel ? > + > + return 0; > +} > + > +int mpx_unregister(struct task_struct *tsk) > +{ > + struct mm_struct *mm = current->mm; > + > + if (!cpu_has_mpx) > + return -EINVAL; > + > + mm->bd_addr = NULL; or indeed calling this in parallel What are the semantics across execve() ? Alan
WARNING: multiple messages have this Message-ID (diff)
From: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> To: Qiaowei Ren <qiaowei.ren@intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com>, Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, Dave Hansen <dave.hansen@intel.com>, x86@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v8 08/10] x86, mpx: add prctl commands PR_MPX_REGISTER, PR_MPX_UNREGISTER Date: Mon, 15 Sep 2014 01:00:25 +0100 [thread overview] Message-ID: <20140915010025.5940c946@alan.etchedpixels.co.uk> (raw) In-Reply-To: <1410425210-24789-9-git-send-email-qiaowei.ren@intel.com> > The base of the bounds directory is set into mm_struct during > PR_MPX_REGISTER command execution. This member can be used to > check whether one application is mpx enabled. Not really because by the time you ask the question another thread might have decided to unregister it. > +int mpx_register(struct task_struct *tsk) > +{ > + struct mm_struct *mm = tsk->mm; > + > + if (!cpu_has_mpx) > + return -EINVAL; > + > + /* > + * runtime in the userspace will be responsible for allocation of > + * the bounds directory. Then, it will save the base of the bounds > + * directory into XSAVE/XRSTOR Save Area and enable MPX through > + * XRSTOR instruction. > + * > + * fpu_xsave() is expected to be very expensive. In order to do > + * performance optimization, here we get the base of the bounds > + * directory and then save it into mm_struct to be used in future. > + */ > + mm->bd_addr = task_get_bounds_dir(tsk); > + if (!mm->bd_addr) > + return -EINVAL; What stops two threads calling this in parallel ? > + > + return 0; > +} > + > +int mpx_unregister(struct task_struct *tsk) > +{ > + struct mm_struct *mm = current->mm; > + > + if (!cpu_has_mpx) > + return -EINVAL; > + > + mm->bd_addr = NULL; or indeed calling this in parallel What are the semantics across execve() ? Alan -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2014-09-15 0:01 UTC|newest] Thread overview: 130+ messages / expand[flat|nested] mbox.gz Atom feed top 2014-09-11 8:46 [PATCH v8 00/10] Intel MPX support Qiaowei Ren 2014-09-11 8:46 ` Qiaowei Ren 2014-09-11 8:46 ` [PATCH v8 01/10] x86, mpx: introduce VM_MPX to indicate that a VMA is MPX specific Qiaowei Ren 2014-09-11 8:46 ` Qiaowei Ren 2014-09-11 8:46 ` [PATCH v8 02/10] x86, mpx: add MPX specific mmap interface Qiaowei Ren 2014-09-11 8:46 ` Qiaowei Ren 2014-09-11 8:46 ` [PATCH v8 03/10] x86, mpx: add macro cpu_has_mpx Qiaowei Ren 2014-09-11 8:46 ` Qiaowei Ren 2014-09-11 8:46 ` [PATCH v8 04/10] x86, mpx: hook #BR exception handler to allocate bound tables Qiaowei Ren 2014-09-11 8:46 ` Qiaowei Ren 2014-09-12 22:58 ` Dave Hansen 2014-09-12 22:58 ` Dave Hansen 2014-09-13 7:24 ` Ren, Qiaowei 2014-09-13 7:24 ` Ren, Qiaowei 2014-09-24 14:40 ` Dave Hansen 2014-09-24 14:40 ` Dave Hansen 2014-09-11 8:46 ` [PATCH v8 05/10] x86, mpx: extend siginfo structure to include bound violation information Qiaowei Ren 2014-09-11 8:46 ` Qiaowei Ren 2014-09-11 8:46 ` [PATCH v8 06/10] mips: sync struct siginfo with general version Qiaowei Ren 2014-09-11 8:46 ` Qiaowei Ren 2014-09-11 22:13 ` Thomas Gleixner 2014-09-11 22:13 ` Thomas Gleixner 2014-09-12 2:54 ` Ren, Qiaowei 2014-09-12 2:54 ` Ren, Qiaowei 2014-09-12 8:17 ` Thomas Gleixner 2014-09-12 8:17 ` Thomas Gleixner 2014-09-13 7:13 ` Ren, Qiaowei 2014-09-13 7:13 ` Ren, Qiaowei 2014-09-11 8:46 ` [PATCH v8 07/10] x86, mpx: decode MPX instruction to get bound violation information Qiaowei Ren 2014-09-11 8:46 ` Qiaowei Ren 2014-09-11 22:18 ` Thomas Gleixner 2014-09-11 22:18 ` Thomas Gleixner 2014-09-11 22:32 ` Dave Hansen 2014-09-11 22:32 ` Dave Hansen 2014-09-11 22:35 ` H. Peter Anvin 2014-09-11 22:35 ` H. Peter Anvin 2014-09-11 23:37 ` Thomas Gleixner 2014-09-11 23:37 ` Thomas Gleixner 2014-09-12 4:44 ` H. Peter Anvin 2014-09-12 4:44 ` H. Peter Anvin 2014-09-12 13:10 ` Thomas Gleixner 2014-09-12 13:10 ` Thomas Gleixner 2014-09-12 13:39 ` H. Peter Anvin 2014-09-12 13:39 ` H. Peter Anvin 2014-09-12 17:48 ` Thomas Gleixner 2014-09-12 17:48 ` Thomas Gleixner 2014-09-12 17:52 ` Thomas Gleixner 2014-09-12 17:52 ` Thomas Gleixner 2014-09-12 19:07 ` H. Peter Anvin 2014-09-12 19:07 ` H. Peter Anvin 2014-09-11 8:46 ` [PATCH v8 08/10] x86, mpx: add prctl commands PR_MPX_REGISTER, PR_MPX_UNREGISTER Qiaowei Ren 2014-09-11 8:46 ` Qiaowei Ren 2014-09-11 15:03 ` Dave Hansen 2014-09-11 15:03 ` Dave Hansen 2014-09-12 3:10 ` Ren, Qiaowei 2014-09-12 3:10 ` Ren, Qiaowei 2014-09-11 23:28 ` Thomas Gleixner 2014-09-11 23:28 ` Thomas Gleixner 2014-09-12 0:10 ` Dave Hansen 2014-09-12 0:10 ` Dave Hansen 2014-09-12 8:11 ` Thomas Gleixner 2014-09-12 8:11 ` Thomas Gleixner 2014-09-12 9:24 ` Thomas Gleixner 2014-09-12 9:24 ` Thomas Gleixner 2014-09-12 14:36 ` Dave Hansen 2014-09-12 14:36 ` Dave Hansen 2014-09-12 17:34 ` Thomas Gleixner 2014-09-12 17:34 ` Thomas Gleixner 2014-09-12 18:42 ` Thomas Gleixner 2014-09-12 18:42 ` Thomas Gleixner 2014-09-12 20:35 ` Dave Hansen 2014-09-12 20:35 ` Dave Hansen 2014-09-12 20:18 ` Dave Hansen 2014-09-12 20:18 ` Dave Hansen 2014-09-13 9:01 ` Thomas Gleixner 2014-09-13 9:01 ` Thomas Gleixner 2014-09-12 15:22 ` Dave Hansen 2014-09-12 15:22 ` Dave Hansen 2014-09-12 17:42 ` Thomas Gleixner 2014-09-12 17:42 ` Thomas Gleixner 2014-09-12 20:33 ` Dave Hansen 2014-09-12 20:33 ` Dave Hansen 2014-09-15 0:00 ` One Thousand Gnomes [this message] 2014-09-15 0:00 ` One Thousand Gnomes 2014-09-16 3:20 ` Ren, Qiaowei 2014-09-16 3:20 ` Ren, Qiaowei 2014-09-16 4:17 ` Dave Hansen 2014-09-16 4:17 ` Dave Hansen 2014-09-16 7:50 ` Kevin Easton 2014-09-16 7:50 ` Kevin Easton 2014-09-18 0:40 ` Ren, Qiaowei 2014-09-18 0:40 ` Ren, Qiaowei 2014-09-18 3:23 ` Kevin Easton 2014-09-18 3:23 ` Kevin Easton 2014-09-18 2:37 ` Ren, Qiaowei 2014-09-18 2:37 ` Ren, Qiaowei 2014-09-18 4:43 ` Dave Hansen 2014-09-18 4:43 ` Dave Hansen 2014-09-18 7:17 ` Kevin Easton 2014-09-18 7:17 ` Kevin Easton 2014-09-18 6:20 ` Dave Hansen 2014-09-18 6:20 ` Dave Hansen 2014-09-11 8:46 ` [PATCH v8 09/10] x86, mpx: cleanup unused bound tables Qiaowei Ren 2014-09-11 8:46 ` Qiaowei Ren 2014-09-11 14:59 ` Dave Hansen 2014-09-11 14:59 ` Dave Hansen 2014-09-12 3:02 ` Ren, Qiaowei 2014-09-12 3:02 ` Ren, Qiaowei 2014-09-12 4:59 ` Dave Hansen 2014-09-12 4:59 ` Dave Hansen 2014-09-15 20:53 ` Dave Hansen 2014-09-15 20:53 ` Dave Hansen 2014-09-16 8:06 ` Ren, Qiaowei 2014-09-16 8:06 ` Ren, Qiaowei 2014-09-11 8:46 ` [PATCH v8 10/10] x86, mpx: add documentation on Intel MPX Qiaowei Ren 2014-09-11 8:46 ` Qiaowei Ren 2014-09-12 0:51 ` [PATCH v8 00/10] Intel MPX support Dave Hansen 2014-09-12 0:51 ` Dave Hansen 2014-09-12 19:21 ` Thomas Gleixner 2014-09-12 19:21 ` Thomas Gleixner 2014-09-12 21:23 ` Dave Hansen 2014-09-12 21:23 ` Dave Hansen 2014-09-13 9:25 ` Thomas Gleixner 2014-09-13 9:25 ` Thomas Gleixner 2014-09-12 21:31 ` Dave Hansen 2014-09-12 21:31 ` Dave Hansen 2014-09-12 22:08 ` Dave Hansen 2014-09-12 22:08 ` Dave Hansen 2014-09-13 9:39 ` Thomas Gleixner 2014-09-13 9:39 ` Thomas Gleixner
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