From: Thomas Gleixner <tglx@linutronix.de>
To: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
x86@kernel.org, Andy Lutomirski <luto@kernel.org>,
Josh Poimboeuf <jpoimboe@redhat.com>
Subject: Re: [patch V2 19/29] x86/exceptions: Split debug IST stack
Date: Fri, 5 Apr 2019 23:01:16 +0200 (CEST) [thread overview]
Message-ID: <alpine.DEB.2.21.1904052300500.1802@nanos.tec.linutronix.de> (raw)
In-Reply-To: <20190405205549.GE15808@linux.intel.com>
On Fri, 5 Apr 2019, Sean Christopherson wrote:
> On Fri, Apr 05, 2019 at 05:07:17PM +0200, Thomas Gleixner wrote:
> > + /*
> > + * Note, this covers the guard page between DB and DB1 as well to
> > + * avoid two checks. But by all means @addr can never point into
> > + * the guard page.
> > + */
> > + return addr > bot && addr < top;
>
> Isn't this an off by one error? I.e. "return addr >= bot && addr < top".
> %rsp == bot is technically still in the DB1 stack even though the next
> PUSH/CALL will explode on the guard page.
Right you are.
next prev parent reply other threads:[~2019-04-05 21:01 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-05 15:06 [patch V2 00/29] x86: Add guard pages to exception and interrupt stacks Thomas Gleixner
2019-04-05 15:06 ` [patch V2 01/29] x86/irq/64: Limit IST stack overflow check to #DB stack Thomas Gleixner
2019-04-05 15:07 ` [patch V2 02/29] x86/dumpstack: Fix off-by-one errors in stack identification Thomas Gleixner
2019-04-05 15:44 ` Sean Christopherson
2019-04-05 15:07 ` [patch V2 03/29] x86/irq/64: Remove a hardcoded irq_stack_union access Thomas Gleixner
2019-04-05 16:37 ` Sean Christopherson
2019-04-05 16:38 ` Sean Christopherson
2019-04-05 17:18 ` Josh Poimboeuf
2019-04-05 17:47 ` Thomas Gleixner
2019-04-05 15:07 ` [patch V2 04/29] x86/irq/64: Sanitize the top/bottom confusion Thomas Gleixner
2019-04-05 16:54 ` Sean Christopherson
2019-04-05 15:07 ` [patch V2 05/29] x86/idt: Remove unused macro SISTG Thomas Gleixner
2019-04-05 15:07 ` [patch V2 06/29] x86/exceptions: Remove unused stack defines on 32bit Thomas Gleixner
2019-04-05 15:07 ` [patch V2 07/29] x86/exceptions: Make IST index zero based Thomas Gleixner
2019-04-05 18:59 ` Sean Christopherson
2019-04-05 15:07 ` [patch V2 08/29] x86/cpu_entry_area: Cleanup setup functions Thomas Gleixner
2019-04-05 19:25 ` Sean Christopherson
2019-04-05 15:07 ` [patch V2 09/29] x86/exceptions: Add structs for exception stacks Thomas Gleixner
2019-04-05 20:48 ` Sean Christopherson
2019-04-05 20:50 ` Sean Christopherson
2019-04-05 21:00 ` Thomas Gleixner
2019-04-05 15:07 ` [patch V2 10/29] x86/cpu_entry_area: Prepare for IST guard pages Thomas Gleixner
2019-04-05 15:07 ` [patch V2 11/29] x86/cpu_entry_area: Provide exception stack accessor Thomas Gleixner
2019-04-05 15:07 ` [patch V2 12/29] x86/traps: Use cpu_entry_area instead of orig_ist Thomas Gleixner
2019-04-05 15:07 ` [patch V2 13/29] x86/irq/64: Use cpu entry area " Thomas Gleixner
2019-04-05 15:07 ` [patch V2 14/29] x86/dumpstack/64: Use cpu_entry_area " Thomas Gleixner
2019-04-05 15:07 ` [patch V2 15/29] x86/cpu: Prepare TSS.IST setup for guard pages Thomas Gleixner
2019-04-05 15:07 ` [patch V2 16/29] x86/cpu: Remove orig_ist array Thomas Gleixner
2019-04-05 15:07 ` [patch V2 17/29] x86/exceptions: Disconnect IST index and stack order Thomas Gleixner
2019-04-05 21:57 ` Josh Poimboeuf
2019-04-05 22:00 ` Thomas Gleixner
2019-04-05 15:07 ` [patch V2 18/29] x86/exceptions: Enable IST guard pages Thomas Gleixner
2019-04-05 15:07 ` [patch V2 19/29] x86/exceptions: Split debug IST stack Thomas Gleixner
2019-04-05 20:55 ` Sean Christopherson
2019-04-05 21:01 ` Thomas Gleixner [this message]
2019-04-05 15:07 ` [patch V2 20/29] x86/dumpstack/64: Speedup in_exception_stack() Thomas Gleixner
2019-04-05 21:55 ` Josh Poimboeuf
2019-04-05 21:56 ` Thomas Gleixner
2019-04-05 15:07 ` [patch V2 21/29] x86/irq/32: Define IRQ_STACK_SIZE Thomas Gleixner
2019-04-05 15:07 ` [patch V2 22/29] x86/irq/32: Make irq stack a character array Thomas Gleixner
2019-04-05 15:07 ` [patch V2 23/29] x86/irq/32: Rename hard/softirq_stack to hard/softirq_stack_ptr Thomas Gleixner
2019-04-05 15:07 ` [patch V2 24/29] x86/irq/64: Rename irq_stack_ptr to hardirq_stack_ptr Thomas Gleixner
2019-04-05 15:07 ` [patch V2 25/29] x86/irq/32: Invoke irq_ctx_init() from init_IRQ() Thomas Gleixner
2019-04-05 15:27 ` Juergen Gross
2019-04-05 15:07 ` [patch V2 26/29] x86/irq/32: Handle irq stack allocation failure proper Thomas Gleixner
2019-04-05 15:07 ` [patch V2 27/29] x86/irq/64: Split the IRQ stack into its own pages Thomas Gleixner
2019-04-05 15:07 ` [patch V2 28/29] x86/irq/64: Remap the IRQ stack with guard pages Thomas Gleixner
2019-04-07 4:56 ` Andy Lutomirski
2019-04-07 6:08 ` Thomas Gleixner
2019-04-07 9:28 ` Andy Lutomirski
2019-04-07 9:34 ` Thomas Gleixner
2019-04-07 14:03 ` Andy Lutomirski
2019-04-07 22:44 ` Thomas Gleixner
2019-04-08 2:23 ` Andy Lutomirski
2019-04-08 6:46 ` Thomas Gleixner
2019-04-08 16:18 ` Andy Lutomirski
2019-04-08 16:36 ` Josh Poimboeuf
2019-04-08 16:44 ` Thomas Gleixner
2019-04-08 18:19 ` Thomas Gleixner
2019-04-05 15:07 ` [patch V2 29/29] x86/irq/64: Remove stack overflow debug code Thomas Gleixner
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