Messages in this thread | | | From | Andy Lutomirski <> | Date | Thu, 2 Jul 2015 08:33:28 -0700 | Subject | Re: [PATCH v4 12/17] x86/asm/entry/64: Save all regs on interrupt entry |
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On Thu, Jul 2, 2015 at 3:52 AM, Borislav Petkov <bp@alien8.de> wrote: > On Mon, Jun 29, 2015 at 12:33:44PM -0700, Andy Lutomirski wrote: >> To prepare for the big rewrite of the error and interrupt exit >> paths, we will need pt_regs completely filled in. It's already >> completely filled in when error_exit runs, so rearrange interrupt >> handling to match it. This will slow down interrupt handling very >> slightly (eight instructions), but the simplification it enables >> will be more than worth it. >> >> Signed-off-by: Andy Lutomirski <luto@kernel.org> >> --- >> arch/x86/entry/entry_64.S | 29 +++++++++-------------------- >> 1 file changed, 9 insertions(+), 20 deletions(-) >> >> diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S >> index 9bc76766aa71..51d34fafe4c0 100644 >> --- a/arch/x86/entry/entry_64.S >> +++ b/arch/x86/entry/entry_64.S >> @@ -502,21 +502,13 @@ END(irq_entries_start) >> /* 0(%rsp): ~(interrupt number) */ >> .macro interrupt func >> cld >> - /* >> - * Since nothing in interrupt handling code touches r12...r15 members >> - * of "struct pt_regs", and since interrupts can nest, we can save >> - * four stack slots and simultaneously provide >> - * an unwind-friendly stack layout by saving "truncated" pt_regs >> - * exactly up to rbp slot, without these members. >> - */ >> - ALLOC_PT_GPREGS_ON_STACK -RBP >> - SAVE_C_REGS -RBP >> - /* this goes to 0(%rsp) for unwinder, not for saving the value: */ >> - SAVE_EXTRA_REGS_RBP -RBP > > That macro's unused now AFAICT. >
I'll delete it in v5.
--Andy
> -- > Regards/Gruss, > Boris. > > ECO tip #101: Trim your mails when you reply. > --
-- Andy Lutomirski AMA Capital Management, LLC
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