Messages in this thread | | | Date | Mon, 11 Aug 2014 02:46:01 +0200 | From | Frederic Weisbecker <> | Subject | Re: [PATCH 4/5] x86: entry_64.S: always allocate complete "struct pt_regs" |
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On Mon, Aug 04, 2014 at 05:03:42AM +0200, Denys Vlasenko wrote: > On Sat, Aug 2, 2014 at 1:19 AM, Frederic Weisbecker <fweisbec@gmail.com> wrote: > >> CFI_ESCAPE 0x0f /* DW_CFA_def_cfa_expression */, 6, \ > >> 0x77 /* DW_OP_breg7 */, 0, \ > >> 0x06 /* DW_OP_deref */, \ > >> - 0x08 /* DW_OP_const1u */, SS+8-RBP, \ > >> + 0x08 /* DW_OP_const1u */, SS+8, \ > >> 0x22 /* DW_OP_plus */ > >> /* We entered an interrupt context - irqs are off: */ > >> TRACE_IRQS_OFF > >> - > >> call \func > >> .endm > >> > >> @@ -749,10 +719,9 @@ ret_from_intr: > >> > >> /* Restore saved previous stack */ > >> popq %rsi > > > > And then you pop to rsi. Ok that indeed works but perhaps we should keep it symetrical > > just for clarity? Any reason why we can't reuse rdi here? > > I changed this entire area in v2: basically, I will not change the logic, > but will add comments explaining what are we doing here, and why. > (Some minor code changes will be done, not affecting the logic). > > While we are at it, what this CFI_ESCAPE thing does here? > As usual, it has no comment :/
I don't know, only Jan Beulich understands those CFI black magic. BTW he doesn't appears to be Cc, we should add him.
> > -- > vda
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