From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Ram Pai <linuxram@us.ibm.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>,
linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
dave.hansen@intel.com, paulus@samba.org,
aneesh.kumar@linux.vnet.ibm.com
Subject: Re: [RFC PATCH 7/7 v1]powerpc: Deliver SEGV signal on protection key violation.
Date: Sat, 17 Jun 2017 08:54:44 +1000 [thread overview]
Message-ID: <1497653684.2897.104.camel@kernel.crashing.org> (raw)
In-Reply-To: <20170616191537.GB17588@ram.oc3035372033.ibm.com>
On Fri, 2017-06-16 at 12:15 -0700, Ram Pai wrote:
> gp_regs size is not changed, nor is the layout. A unused field in
> the gp_regs is used to fill in the AMR contents. Old binaries will not
> be knowing about this unused field, and hence should not break.
>
> New binaries can leverage this already existing but newly defined
> field; to read the contents of AMR.
>
> Is it still a concern?
Calls to sys_swapcontext with a made-up context will end up with a crap
AMR if done by code who didn't know about that register.
Ben.
next prev parent reply other threads:[~2017-06-16 22:55 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-06 1:05 [RFC PATCH 0/7 v1] powerpc: Memory Protection Keys Ram Pai
2017-06-06 1:05 ` [RFC PATCH 1/7 v1]powerpc: Free up four PTE bits to accommodate memory keys Ram Pai
2017-06-12 6:57 ` Aneesh Kumar K.V
2017-06-12 22:20 ` Ram Pai
2017-06-13 2:02 ` Aneesh Kumar K.V
2017-06-13 21:51 ` Ram Pai
2017-06-13 4:52 ` Aneesh Kumar K.V
2017-06-13 21:52 ` Ram Pai
2017-06-06 1:05 ` [RFC PATCH 2/7 v1]powerpc: Implement sys_pkey_alloc and sys_pkey_free system call Ram Pai
2017-06-06 1:05 ` [RFC PATCH 3/7 v1]powerpc: store and restore the key state across context switches Ram Pai
2017-06-06 1:05 ` [RFC PATCH 4/7 v1]powerpc: Implementation for sys_mprotect_pkey() system call Ram Pai
2017-06-06 1:05 ` [RFC PATCH 5/7 v1]powerpc: Program HPTE key protection bits Ram Pai
2017-06-06 1:05 ` [RFC PATCH 6/7 v1]powerpc: Handle exceptions caused by violation of key protection Ram Pai
2017-06-06 1:05 ` [RFC PATCH 7/7 v1]powerpc: Deliver SEGV signal on protection key violation Ram Pai
2017-06-16 9:20 ` Anshuman Khandual
2017-06-16 10:33 ` Benjamin Herrenschmidt
2017-06-16 19:15 ` Ram Pai
2017-06-16 22:54 ` Benjamin Herrenschmidt [this message]
2017-06-22 21:41 ` Ram Pai
2017-06-16 19:10 ` Ram Pai
2017-06-16 11:18 ` Michael Ellerman
2017-06-16 19:35 ` Ram Pai
2017-06-20 7:07 ` [RFC PATCH 0/7 v1] powerpc: Memory Protection Keys Pavel Machek
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