Re: [patch V6 07/37] x86/entry: Provide helpers for execute on irqstack

2020-05-20 Thread Andy Lutomirski
On Wed, May 20, 2020 at 8:27 AM Thomas Gleixner wrote: > > Andy Lutomirski writes: > > On Wed, May 20, 2020 at 5:35 AM Thomas Gleixner wrote: > >> > >> Andy Lutomirski writes: > >> > On Mon, May 18, 2020 at 4:53 PM Thomas Gleixner > >> > wrote: > >> >> > >> >> Andy Lutomirski writes: > >>

Re: [patch V6 07/37] x86/entry: Provide helpers for execute on irqstack

2020-05-20 Thread Thomas Gleixner
Andy Lutomirski writes: > On Wed, May 20, 2020 at 5:35 AM Thomas Gleixner wrote: >> >> Andy Lutomirski writes: >> > On Mon, May 18, 2020 at 4:53 PM Thomas Gleixner wrote: >> >> >> >> Andy Lutomirski writes: >> >> > Actually, I revoke my ack. Can you make one of two changes: >> >> > >> >> >

Re: [patch V6 07/37] x86/entry: Provide helpers for execute on irqstack

2020-05-20 Thread Andy Lutomirski
On Wed, May 20, 2020 at 5:35 AM Thomas Gleixner wrote: > > Andy Lutomirski writes: > > On Mon, May 18, 2020 at 4:53 PM Thomas Gleixner wrote: > >> > >> Andy Lutomirski writes: > >> > Actually, I revoke my ack. Can you make one of two changes: > >> > > >> > Option A: Add an assertion to

Re: [patch V6 07/37] x86/entry: Provide helpers for execute on irqstack

2020-05-20 Thread Thomas Gleixner
Andy Lutomirski writes: > On Mon, May 18, 2020 at 4:53 PM Thomas Gleixner wrote: >> >> Andy Lutomirski writes: >> > Actually, I revoke my ack. Can you make one of two changes: >> > >> > Option A: Add an assertion to run_on_irqstack to verify that irq_count >> > was -1 at the beginning? I

Re: [patch V6 07/37] x86/entry: Provide helpers for execute on irqstack

2020-05-18 Thread Andy Lutomirski
On Mon, May 18, 2020 at 4:53 PM Thomas Gleixner wrote: > > Andy Lutomirski writes: > > Actually, I revoke my ack. Can you make one of two changes: > > > > Option A: Add an assertion to run_on_irqstack to verify that irq_count > > was -1 at the beginning? I suppose this also means you could

Re: [patch V6 07/37] x86/entry: Provide helpers for execute on irqstack

2020-05-18 Thread Thomas Gleixner
Andy Lutomirski writes: > Actually, I revoke my ack. Can you make one of two changes: > > Option A: Add an assertion to run_on_irqstack to verify that irq_count > was -1 at the beginning? I suppose this also means you could just > explicitly write 0 instead of adding and subtracting. > > Option

Re: [patch V6 07/37] x86/entry: Provide helpers for execute on irqstack

2020-05-18 Thread Thomas Gleixner
Andy Lutomirski writes: > On Fri, May 15, 2020 at 5:10 PM Thomas Gleixner wrote: > > Have you tested by forcing a stack trace from the IRQ stack and making > sure it unwinds all the way out? Yes.

Re: [patch V6 07/37] x86/entry: Provide helpers for execute on irqstack

2020-05-18 Thread Andy Lutomirski
On Mon, May 18, 2020 at 4:11 PM Andy Lutomirski wrote: > > On Fri, May 15, 2020 at 5:10 PM Thomas Gleixner wrote: > > > > > > Device interrupt handlers and system vector handlers are executed on the > > interrupt stack. The stack switch happens in the low level assembly entry > > code. This

Re: [patch V6 07/37] x86/entry: Provide helpers for execute on irqstack

2020-05-18 Thread Andy Lutomirski
On Fri, May 15, 2020 at 5:10 PM Thomas Gleixner wrote: > > > Device interrupt handlers and system vector handlers are executed on the > interrupt stack. The stack switch happens in the low level assembly entry > code. This conflicts with the efforts to consolidate the exit code in C to > ensure

[patch V6 07/37] x86/entry: Provide helpers for execute on irqstack

2020-05-15 Thread Thomas Gleixner
Device interrupt handlers and system vector handlers are executed on the interrupt stack. The stack switch happens in the low level assembly entry code. This conflicts with the efforts to consolidate the exit code in C to ensure correctness vs. RCU and tracing. As there is no way to move #DB