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From: Thomas Gleixner <tglx@linutronix.de>
To: Ingo Molnar <mingo@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
	x86@kernel.org, Stephen Hemminger <stephen@networkplumber.org>,
	Willy Tarreau <w@1wt.eu>, Juergen Gross <jgross@suse.com>,
	Sean Christopherson <sean.j.christopherson@intel.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	"H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [patch 5/9] x86/ioport: Reduce ioperm impact for sane usage further
Date: Thu, 7 Nov 2019 08:45:26 +0100 (CET)	[thread overview]
Message-ID: <alpine.DEB.2.21.1911070844550.1869@nanos.tec.linutronix.de> (raw)
In-Reply-To: <20191107073719.GD30739@gmail.com>

[-- Attachment #1: Type: text/plain, Size: 1438 bytes --]

On Thu, 7 Nov 2019, Ingo Molnar wrote:
> * Thomas Gleixner <tglx@linutronix.de> wrote:
> >  	/*
> > -	 * The extra 1 is there because the CPU will access an
> > -	 * additional byte beyond the end of the IO permission
> > -	 * bitmap. The extra byte must be all 1 bits, and must
> > -	 * be within the limit.
> > +	 * The extra 1 is there because the CPU will access an additional
> > +	 * byte beyond the end of the I/O permission bitmap. The extra byte
> > +	 * must have all bits set and must be within the TSS limit.
> >  	 */
> >  	unsigned long		io_bitmap[IO_BITMAP_LONGS + 1];
> >  } __aligned(PAGE_SIZE);
> 
> Note that on 32-bit kernels this blows up our CPU area calculations:
> 
> ./include/linux/compiler.h:350:38: error: call to ‘__compiletime_assert_181’ declared with attribute error: BUILD_BUG_ON failed: CPU_ENTRY_AREA_PAGES * PAGE_SIZE < CPU_ENTRY_AREA_MAP_SIZE
> ./include/linux/compiler.h:331:4: note: in definition of macro ‘__compiletime_assert’
> ./include/linux/compiler.h:350:2: note: in expansion of macro ‘_compiletime_assert’
> ./include/linux/build_bug.h:39:37: note: in expansion of macro ‘compiletime_assert’
> ./include/linux/build_bug.h:50:2: note: in expansion of macro ‘BUILD_BUG_ON_MSG’
> arch/x86/mm/cpu_entry_area.c:181:2: note: in expansion of macro ‘BUILD_BUG_ON’
> make[2]: *** [scripts/Makefile.build:265: arch/x86/mm/cpu_entry_area.o] Error 1

Duh. /me goes investigate.

  reply	other threads:[~2019-11-07  7:45 UTC|newest]

Thread overview: 62+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-06 19:34 [patch 0/9] x86/iopl: Prevent user space from using CLI/STI with iopl(3) Thomas Gleixner
2019-11-06 19:35 ` [patch 1/9] x86/ptrace: Prevent truncation of bitmap size Thomas Gleixner
2019-11-07  7:31   ` Ingo Molnar
2019-11-06 19:35 ` [patch 2/9] x86/process: Unify copy_thread_tls() Thomas Gleixner
2019-11-08 22:31   ` Andy Lutomirski
2019-11-08 23:43     ` Thomas Gleixner
2019-11-10 12:36       ` Thomas Gleixner
2019-11-10 16:56         ` Andy Lutomirski
2019-11-11  8:52           ` Peter Zijlstra
2019-11-06 19:35 ` [patch 3/9] x86/cpu: Unify cpu_init() Thomas Gleixner
2019-11-08 22:34   ` Andy Lutomirski
2019-11-06 19:35 ` [patch 4/9] x86/io: Speedup schedule out of I/O bitmap user Thomas Gleixner
2019-11-07  9:12   ` Peter Zijlstra
2019-11-07 14:04     ` Thomas Gleixner
2019-11-07 14:08       ` Thomas Gleixner
2019-11-08 22:41         ` Andy Lutomirski
2019-11-08 23:45           ` Thomas Gleixner
2019-11-09  3:32             ` Andy Lutomirski
2019-11-10 12:43               ` Thomas Gleixner
2019-11-09  0:24   ` Andy Lutomirski
2019-11-06 19:35 ` [patch 5/9] x86/ioport: Reduce ioperm impact for sane usage further Thomas Gleixner
2019-11-07  1:11   ` Linus Torvalds
2019-11-07  7:44     ` Thomas Gleixner
2019-11-07  8:25     ` Ingo Molnar
2019-11-07  9:17       ` Willy Tarreau
2019-11-07 10:00         ` Thomas Gleixner
2019-11-07 10:13           ` Willy Tarreau
2019-11-07 10:19           ` hpa
2019-11-07 10:27             ` Willy Tarreau
2019-11-07 10:50               ` hpa
2019-11-07 12:56                 ` Willy Tarreau
2019-11-07 16:45                   ` Eric W. Biederman
2019-11-07 16:53                     ` Linus Torvalds
2019-11-07 16:57                     ` Willy Tarreau
2019-11-10 17:17       ` Andy Lutomirski
2019-11-07  7:37   ` Ingo Molnar
2019-11-07  7:45     ` Thomas Gleixner [this message]
2019-11-07  8:16   ` Ingo Molnar
2019-11-07 18:02     ` Thomas Gleixner
2019-11-07 19:24   ` Brian Gerst
2019-11-07 19:54     ` Linus Torvalds
2019-11-07 21:00       ` Brian Gerst
2019-11-07 21:32         ` Thomas Gleixner
2019-11-07 23:20           ` hpa
2019-11-07 21:44         ` Linus Torvalds
2019-11-08  1:12           ` H. Peter Anvin
2019-11-08  2:12             ` Brian Gerst
2019-11-10 17:21           ` Andy Lutomirski
2019-11-06 19:35 ` [patch 6/9] x86/iopl: Fixup misleading comment Thomas Gleixner
2019-11-06 19:35 ` [patch 7/9] x86/iopl: Restrict iopl() permission scope Thomas Gleixner
2019-11-07  9:09   ` Peter Zijlstra
2019-11-10 17:26   ` Andy Lutomirski
2019-11-10 20:31     ` Thomas Gleixner
2019-11-10 21:05       ` Andy Lutomirski
2019-11-10 21:21         ` Thomas Gleixner
2019-11-06 19:35 ` [patch 8/9] x86/iopl: Remove legacy IOPL option Thomas Gleixner
2019-11-07  6:11   ` Jürgen Groß
2019-11-07  6:26     ` hpa
2019-11-07 16:44     ` Stephen Hemminger
2019-11-07  9:13   ` Peter Zijlstra
2019-11-06 19:35 ` [patch 9/9] selftests/x86/iopl: Verify that CLI/STI result in #GP Thomas Gleixner
2019-11-07  7:28 ` [patch] x86/iopl: Remove unused local variable, update comments in ksys_ioperm() Ingo Molnar

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