Messages in this thread | | | Date | Mon, 8 Apr 2019 11:36:32 -0500 | From | Josh Poimboeuf <> | Subject | Re: [patch V2 28/29] x86/irq/64: Remap the IRQ stack with guard pages |
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On Mon, Apr 08, 2019 at 09:18:00AM -0700, Andy Lutomirski wrote: > On Sun, Apr 7, 2019 at 11:46 PM Thomas Gleixner <tglx@linutronix.de> wrote: > > > > On Sun, 7 Apr 2019, Andy Lutomirski wrote: > > > On Sun, Apr 7, 2019 at 3:44 PM Thomas Gleixner <tglx@linutronix.de> wrote: > > > > Actually we have: save_stack_trace() > > > > > > > > > > Like I did here: > > > > > > https://git.kernel.org/pub/scm/linux/kernel/git/luto/linux.git/log/?h=WIP.x86/stackguards > > > > Kinda, but what that code wants is to skip any entry before 'caller'. So we > > either add something like save_stack_trace_from() which is trivial on x86 > > because unwind_start() already has an argument to hand in the start of > > stack or we filter out the entries up to 'caller' in that code. > > > > > > Whoops! > > I could add a save_stack_trace_from() or I could add a "caller" > argument to struct stack_trace. Any preference as to which looks > better? The latter seems a little nicer to me.
The current official way to do that is to use the stack_trace "skip" field. That's a hack though because it relies on inlining decisions.
It would be nicer if the skip interface were pointer-based like your suggestion.
-- Josh
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