Messages in this thread | | | From | Andy Lutomirski <> | Date | Wed, 13 May 2020 21:31:32 -0700 | Subject | Re: [patch V4 part 3 09/29] x86/entry/32: Provide macro to emit IDT entry stubs |
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On Wed, May 13, 2020 at 6:44 PM Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote: > > ----- On May 5, 2020, at 9:44 AM, Thomas Gleixner tglx@linutronix.de wrote: > > [...] > > > +.macro idtentry vector asmsym cfunc has_error_code:req sane=0 > > +SYM_CODE_START(\asmsym) > > + ASM_CLAC > > + cld > > Looking at the various interrupt and trap entry points for 32 and 64-bit > x86, I notice a lack of consistency in use of the following instruction > sequence at the asm entry point: > > - ASM_CLAC, > - cld (clear direction flag). > > Are they always needed, or only for interrupt handlers ?
They're needed for all entries except SYSCALL, but they're hidden inside helpers in many cases.
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