From: Dave Hansen <dave@sr71.net>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org, x86@kernel.org,
dave.hansen@linux.intel.com
Subject: Re: [PATCH 09/19] x86, mpx: trace entry to bounds exception paths
Date: Mon, 18 May 2015 16:06:47 -0700 [thread overview]
Message-ID: <555A7087.5080409@sr71.net> (raw)
In-Reply-To: <alpine.DEB.2.11.1505182246290.4225@nanos>
On 05/18/2015 01:58 PM, Thomas Gleixner wrote:
> On Fri, 8 May 2015, Dave Hansen wrote:
>> > This patch adds a trace point for the case where we are
>> > passing the exception up to userspace with a signal.
>> >
>> > We are also explicit that we're printing out the inverse of
>> > the 'upper' that we encounter. If you want to filter, for
>> > instance, you need to ~ the value first.
> Confused. What is the point of printing the complement of upper?
If a pointer's range is
0x1000 -> 0x2000
it is stored in the bounds table as (32-bits here for brevity):
lower: 0x00001000
upper: 0xffffdfff
That is so that an all 0's entry:
lower: 0x00000000
upper: 0x00000000
corresponds to the "init" bounds which store a *range* of:
0x00000000 -> 0xffffffff
The 'upper' stored in the table is gibberish to print by itself, so we
print ~upper to get the *actual*, logical value.
next prev parent reply other threads:[~2015-05-18 23:06 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-08 18:59 [PATCH 00/19] x86, mpx updates for 4.2 (take 6) Dave Hansen
2015-05-08 18:59 ` [PATCH 01/19] x86, mpx, xsave: fix up bad get_xsave_addr() assumptions Dave Hansen
2015-05-18 19:34 ` Thomas Gleixner
2015-05-08 18:59 ` [PATCH 03/19] x86, mpx: use new tsk_get_xsave_addr() Dave Hansen
2015-05-18 20:36 ` Thomas Gleixner
2015-05-19 0:01 ` Dave Hansen
2015-05-08 18:59 ` [PATCH 02/19] x86, fpu: wrap get_xsave_addr() to make it safer Dave Hansen
2015-05-18 19:38 ` Thomas Gleixner
2015-05-18 19:42 ` Thomas Gleixner
2015-05-08 18:59 ` [PATCH 04/19] x86, mpx: cleanup: do not pass task around when unnecessary Dave Hansen
2015-05-18 20:38 ` Thomas Gleixner
2015-05-08 18:59 ` [PATCH 05/19] x86, mpx: remove redundant MPX_BNDCFG_ADDR_MASK Dave Hansen
2015-05-18 20:38 ` Thomas Gleixner
2015-05-08 18:59 ` [PATCH 06/19] x86, mpx: we do not allocate the bounds directory Dave Hansen
2015-05-18 20:43 ` Thomas Gleixner
2015-05-08 18:59 ` [PATCH 07/19] x86, mpx: boot-time disable Dave Hansen
2015-05-18 20:45 ` Thomas Gleixner
2015-05-08 18:59 ` [PATCH 08/19] x86, mpx: trace #BR exceptions Dave Hansen
2015-05-18 21:00 ` Thomas Gleixner
2015-05-08 18:59 ` [PATCH 09/19] x86, mpx: trace entry to bounds exception paths Dave Hansen
2015-05-18 20:58 ` Thomas Gleixner
2015-05-18 23:06 ` Dave Hansen [this message]
2015-05-18 23:35 ` Thomas Gleixner
2015-05-08 18:59 ` [PATCH 10/19] x86, mpx: trace ranged MPX operations Dave Hansen
2015-05-18 21:04 ` Thomas Gleixner
2015-05-08 18:59 ` [PATCH 12/19] x86: make is_64bit_mm() widely available Dave Hansen
2015-05-18 21:06 ` Thomas Gleixner
2015-05-08 18:59 ` [PATCH 11/19] x86, mpx: trace allocation of new bounds tables Dave Hansen
2015-05-18 21:04 ` Thomas Gleixner
2015-05-08 18:59 ` [PATCH 13/19] x86, mpx: Add temporary variable to reduce masking Dave Hansen
2015-05-18 21:07 ` Thomas Gleixner
2015-05-08 18:59 ` [PATCH 14/19] x86, mpx: new directory entry to addr helper Dave Hansen
2015-05-18 21:10 ` Thomas Gleixner
2015-05-08 18:59 ` [PATCH 15/19] x86, mpx: do 32-bit-only cmpxchg for 32-bit apps Dave Hansen
2015-05-18 21:22 ` Thomas Gleixner
2015-05-08 18:59 ` [PATCH 16/19] x86, mpx: support 32-bit binaries on 64-bit kernel Dave Hansen
2015-05-18 21:53 ` Thomas Gleixner
2015-05-18 23:29 ` Dave Hansen
2015-05-18 23:37 ` Thomas Gleixner
2015-05-08 18:59 ` [PATCH 17/19] x86, mpx: rewrite unmap code Dave Hansen
2015-05-18 21:55 ` Thomas Gleixner
2015-05-08 18:59 ` [PATCH 18/19] x86, mpx: do not count MPX VMAs as neighbors when unmapping Dave Hansen
2015-05-18 21:54 ` Thomas Gleixner
2015-05-08 18:59 ` [PATCH 19/19] x86, mpx: allow mixed binaries again Dave Hansen
2015-05-18 21:55 ` Thomas Gleixner
-- strict thread matches above, loose matches on Subject: below --
2015-05-19 6:25 [PATCH 00/19] x86, mpx updates for 4.2 (take 7) Dave Hansen
2015-05-19 6:25 ` [PATCH 09/19] x86, mpx: trace entry to bounds exception paths Dave Hansen
2015-05-19 8:17 ` Thomas Gleixner
2015-05-27 18:36 [PATCH 00/19] x86, mpx updates for 4.2 (take 8) Dave Hansen
2015-05-27 18:36 ` [PATCH 09/19] x86, mpx: trace entry to bounds exception paths Dave Hansen
2015-06-07 18:37 [PATCH 00/19] x86, mpx updates for 4.2 (take 9) Dave Hansen
2015-06-07 18:37 ` [PATCH 09/19] x86, mpx: trace entry to bounds exception paths Dave Hansen
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