Re: [RFA][PATCH] Stack clash protection 07/08 -- V4 (aarch64 bits)

2017-12-18 Thread Jeff Law
On 11/27/2017 11:44 AM, James Greenhalgh wrote: > On Wed, Nov 22, 2017 at 06:28:24PM +, Jeff Law wrote: >> On 11/21/2017 04:57 AM, James Greenhalgh wrote: >>> I've finally built up enough courage to start getting my head around this... >> Can't blame you for avoiding :-) This stuff isn't my

Re: [RFA][PATCH] Stack clash protection 07/08 -- V4 (aarch64 bits)

2017-11-28 Thread Rich Felker
On Mon, Nov 27, 2017 at 03:48:41PM +, Szabolcs Nagy wrote: > On 28/10/17 05:08, Jeff Law wrote: > > On 10/13/2017 02:26 PM, Wilco Dijkstra wrote: > >> For larger frames the first oddity is that there are now 2 separate params > >> controlling how probes are generated: > >> > >>

Re: [RFA][PATCH] Stack clash protection 07/08 -- V4 (aarch64 bits)

2017-11-27 Thread James Greenhalgh
On Wed, Nov 22, 2017 at 06:28:24PM +, Jeff Law wrote: > On 11/21/2017 04:57 AM, James Greenhalgh wrote: > > I've finally built up enough courage to start getting my head around this... > Can't blame you for avoiding :-) This stuff isn't my idea of fun either. Right, here's where I'm up to...

Re: [RFA][PATCH] Stack clash protection 07/08 -- V4 (aarch64 bits)

2017-11-27 Thread Jeff Law
On 11/27/2017 10:33 AM, Wilco Dijkstra wrote: > Szabolcs Nagy wrote: >> On 28/10/17 05:08, Jeff Law wrote: >> >>> My hope would be that we simply don't ever use the params.  They were >>> done as much for *you* to experiment with as anything.  I'd happy just >>> delete them as there's essentially

Re: [RFA][PATCH] Stack clash protection 07/08 -- V4 (aarch64 bits)

2017-11-27 Thread Jeff Law
On 11/27/2017 08:48 AM, Szabolcs Nagy wrote: > On 28/10/17 05:08, Jeff Law wrote: >> On 10/13/2017 02:26 PM, Wilco Dijkstra wrote: >>> For larger frames the first oddity is that there are now 2 separate params >>> controlling how probes are generated: >>> >>> stack-clash-protection-guard-size

Re: [RFA][PATCH] Stack clash protection 07/08 -- V4 (aarch64 bits)

2017-11-27 Thread Wilco Dijkstra
Szabolcs Nagy wrote: >On 28/10/17 05:08, Jeff Law wrote: > >> My hope would be that we simply don't ever use the params.  They were >> done as much for *you* to experiment with as anything.  I'd happy just >> delete them as there's essentially no guard rails to ensure their values >> are sane. > >

Re: [RFA][PATCH] Stack clash protection 07/08 -- V4 (aarch64 bits)

2017-11-27 Thread Szabolcs Nagy
On 28/10/17 05:08, Jeff Law wrote: > On 10/13/2017 02:26 PM, Wilco Dijkstra wrote: >> For larger frames the first oddity is that there are now 2 separate params >> controlling how probes are generated: >> >> stack-clash-protection-guard-size (default 12, but set to 16 on AArch64) >>

Re: [RFA][PATCH] Stack clash protection 07/08 -- V4 (aarch64 bits)

2017-11-22 Thread Jeff Law
On 11/21/2017 04:57 AM, James Greenhalgh wrote: > I've finally built up enough courage to start getting my head around this... Can't blame you for avoiding :-) This stuff isn't my idea of fun either. > > I see one outstanding issue sitting on this patch version: > > On Sat, Oct 28, 2017 at

Re: [RFA][PATCH] Stack clash protection 07/08 -- V4 (aarch64 bits)

2017-11-21 Thread James Greenhalgh
I've finally built up enough courage to start getting my head around this... I see one outstanding issue sitting on this patch version: On Sat, Oct 28, 2017 at 05:08:54AM +0100, Jeff Law wrote: > On 10/13/2017 02:26 PM, Wilco Dijkstra wrote: > > --param=stack-clash-protection-probe-interval=13 >

Re: [RFA][PATCH] Stack clash protection 07/08 -- V4 (aarch64 bits)

2017-10-27 Thread Jeff Law
On 10/13/2017 02:26 PM, Wilco Dijkstra wrote: > Hi, > > To continue the review of the AArch64 frame code I tried a few examples > to figure out what it does now. For initial_adjust <= 63*1024 and > final_adjust < > 1024 there are no probes inserted as expected, ie. the vast majority of >

Re: [RFA][PATCH] Stack clash protection 07/08 -- V4 (aarch64 bits)

2017-10-13 Thread Wilco Dijkstra
Hi, To continue the review of the AArch64 frame code I tried a few examples to figure out what it does now. For initial_adjust <= 63*1024 and final_adjust < 1024 there are no probes inserted as expected, ie. the vast majority of functions are unaffected. So that works perfectly. For larger

Re: [RFA][PATCH] Stack clash protection 07/08 -- V4 (aarch64 bits)

2017-10-13 Thread Wilco Dijkstra
Hi, Sorry for the delay - I finally had a chance to look at this again. I'll start with alloca: @@ -15245,6 +15455,28 @@ aarch64_sched_can_speculate_insn (rtx_insn *insn) }  }   +/* It has been decided that to allow up to 1kb of outgoing argument +   space to be allocated w/o probing.  If

[RFA][PATCH] Stack clash protection 07/08 -- V4 (aarch64 bits)

2017-09-29 Thread Jeff Law
Wilco has done most of the design/implementation review work to-date and should have state on most of this code. -- Here's the current aarch64 patch for stack clash protection. It's the only bits for stack clash protection that haven't been committed to the trunk. Looking through my archives