Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [patch V4 part 3 09/29] x86/entry/32: Provide macro to emit IDT entry stubs | Date | Thu, 14 May 2020 16:08:04 +0200 |
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Mathieu Desnoyers <mathieu.desnoyers@efficios.com> writes: > ----- On May 14, 2020, at 12:31 AM, Andy Lutomirski luto@kernel.org wrote: >> On Wed, May 13, 2020 at 6:44 PM Mathieu Desnoyers >> <mathieu.desnoyers@efficios.com> wrote: >> They're needed for all entries except SYSCALL, but they're hidden >> inside helpers in many cases. > > Indeed, on x86-32 the macro SAVE_ALL contains cld. That architecture > appears to be OK. > > What I am concerned about is the idtentry, idtentry_mce_db, > and idtentry_df macros introduced in entry_64.S by this series. > Those are supposed to be technically equivalent to the prior > code, which indeed has the ASM_CLAC but no "cld". > > So maybe the cld happens to be hidden elsewhere, but I'm clearly > missing it ? Or is it not needed for some reason ?
It's needed and it is there where it was forever in error_entry and paranoid_entry.
It probably makes sense to stick it right after the CLAC.
Thanks,
tglx
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