Re: [PATCH] x86/debug: 'Fix' ptrace dr6 output

2021-01-28 Thread Tom de Vries
On 1/28/21 7:20 PM, Peter Zijlstra wrote: > > Tom reported that one of the GDB test-cases failed, and Boris bisected > it to commit: > > d53d9bc0cf78 ("x86/debug: Change thread.debugreg6 to thread.virtual_dr6") > > The debugging session led us to commit: > > 6c0aca288e72 ("x86: Ignore trap

Re: [PATCH] x86/debug: 'Fix' ptrace dr6 output

2021-01-28 Thread Andrew Cooper
On 28/01/2021 18:20, Peter Zijlstra wrote: > --- a/arch/x86/kernel/hw_breakpoint.c > +++ b/arch/x86/kernel/hw_breakpoint.c > @@ -496,9 +496,32 @@ static int hw_breakpoint_handler(struct > dr6_p = (unsigned long *)ERR_PTR(args->err); > dr6 = *dr6_p; > > - /* If it's a single step,

[PATCH] x86/debug: 'Fix' ptrace dr6 output

2021-01-28 Thread Peter Zijlstra
Tom reported that one of the GDB test-cases failed, and Boris bisected it to commit: d53d9bc0cf78 ("x86/debug: Change thread.debugreg6 to thread.virtual_dr6") The debugging session led us to commit: 6c0aca288e72 ("x86: Ignore trap bits on single step exceptions") Which describes a nice