Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755398AbbDUS5F (ORCPT ); Tue, 21 Apr 2015 14:57:05 -0400 Received: from mail-la0-f41.google.com ([209.85.215.41]:35752 "EHLO mail-la0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751753AbbDUS5B (ORCPT ); Tue, 21 Apr 2015 14:57:01 -0400 MIME-Version: 1.0 In-Reply-To: <8a03355698fe5b94194e9e7360f19f91c1b2cf1f.1428100853.git.luto@kernel.org> References: <8a03355698fe5b94194e9e7360f19f91c1b2cf1f.1428100853.git.luto@kernel.org> From: Andy Lutomirski Date: Tue, 21 Apr 2015 11:56:39 -0700 Message-ID: Subject: Re: [PATCH] x86, paravirt, xen: Remove the 64-bit irq_enable_sysexit pvop To: Andy Lutomirski , Ingo Molnar Cc: Linux Kernel Mailing List , X86 ML , Denys Vlasenko , Linus Torvalds , Denys Vlasenko , "H. Peter Anvin" , Borislav Petkov Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6933 Lines: 188 On Fri, Apr 3, 2015 at 3:51 PM, Andy Lutomirski wrote: > We don't use irq_enable_sysexit on 64-bit kernels any more. Remove > all the paravirt and Xen machinery to support it on 64-bit kernels. > > Signed-off-by: Andy Lutomirski Hi, Ingo, Can you pick this up in -tip? It cleans up code that would otherwise be unreachable in 4.1, but it doesn't fix any bugs, so waiting for 4.2 would be fine as well. --Andy > --- > > I haven't actually tested this on Xen, but it builds for me. > > arch/x86/ia32/ia32entry.S | 6 ------ > arch/x86/include/asm/paravirt_types.h | 7 ++++--- > arch/x86/kernel/asm-offsets.c | 2 ++ > arch/x86/kernel/paravirt.c | 4 +++- > arch/x86/kernel/paravirt_patch_64.c | 1 - > arch/x86/xen/enlighten.c | 3 ++- > arch/x86/xen/xen-asm_64.S | 16 ---------------- > arch/x86/xen/xen-ops.h | 2 ++ > 8 files changed, 13 insertions(+), 28 deletions(-) > > diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S > index 5d8f987a340d..eb1eb7b70f4b 100644 > --- a/arch/x86/ia32/ia32entry.S > +++ b/arch/x86/ia32/ia32entry.S > @@ -77,12 +77,6 @@ ENTRY(native_usergs_sysret32) > swapgs > sysretl > ENDPROC(native_usergs_sysret32) > - > -ENTRY(native_irq_enable_sysexit) > - swapgs > - sti > - sysexit > -ENDPROC(native_irq_enable_sysexit) > #endif > > /* > diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h > index 7549b8b369e4..38a0ff9ef06e 100644 > --- a/arch/x86/include/asm/paravirt_types.h > +++ b/arch/x86/include/asm/paravirt_types.h > @@ -160,13 +160,14 @@ struct pv_cpu_ops { > u64 (*read_pmc)(int counter); > unsigned long long (*read_tscp)(unsigned int *aux); > > +#ifdef CONFIG_X86_32 > /* > * Atomically enable interrupts and return to userspace. This > - * is only ever used to return to 32-bit processes; in a > - * 64-bit kernel, it's used for 32-on-64 compat processes, but > - * never native 64-bit processes. (Jump, not call.) > + * is only used in 32-bit kernels. 64-bit kernels use > + * usergs_sysret32 instead. > */ > void (*irq_enable_sysexit)(void); > +#endif > > /* > * Switch to usermode gs and return to 64-bit usermode using > diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c > index 9f6b9341950f..2d27ebf0aed8 100644 > --- a/arch/x86/kernel/asm-offsets.c > +++ b/arch/x86/kernel/asm-offsets.c > @@ -49,7 +49,9 @@ void common(void) { > OFFSET(PV_IRQ_irq_disable, pv_irq_ops, irq_disable); > OFFSET(PV_IRQ_irq_enable, pv_irq_ops, irq_enable); > OFFSET(PV_CPU_iret, pv_cpu_ops, iret); > +#ifdef CONFIG_X86_32 > OFFSET(PV_CPU_irq_enable_sysexit, pv_cpu_ops, irq_enable_sysexit); > +#endif > OFFSET(PV_CPU_read_cr0, pv_cpu_ops, read_cr0); > OFFSET(PV_MMU_read_cr2, pv_mmu_ops, read_cr2); > #endif > diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c > index 548d25f00c90..7563114d9c3a 100644 > --- a/arch/x86/kernel/paravirt.c > +++ b/arch/x86/kernel/paravirt.c > @@ -154,7 +154,9 @@ unsigned paravirt_patch_default(u8 type, u16 clobbers, void *insnbuf, > ret = paravirt_patch_ident_64(insnbuf, len); > > else if (type == PARAVIRT_PATCH(pv_cpu_ops.iret) || > +#ifdef CONFIG_X86_32 > type == PARAVIRT_PATCH(pv_cpu_ops.irq_enable_sysexit) || > +#endif > type == PARAVIRT_PATCH(pv_cpu_ops.usergs_sysret32) || > type == PARAVIRT_PATCH(pv_cpu_ops.usergs_sysret64)) > /* If operation requires a jmp, then jmp */ > @@ -371,7 +373,7 @@ __visible struct pv_cpu_ops pv_cpu_ops = { > > .load_sp0 = native_load_sp0, > > -#if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION) > +#if defined(CONFIG_X86_32) > .irq_enable_sysexit = native_irq_enable_sysexit, > #endif > #ifdef CONFIG_X86_64 > diff --git a/arch/x86/kernel/paravirt_patch_64.c b/arch/x86/kernel/paravirt_patch_64.c > index a1da6737ba5b..0de21c62c348 100644 > --- a/arch/x86/kernel/paravirt_patch_64.c > +++ b/arch/x86/kernel/paravirt_patch_64.c > @@ -49,7 +49,6 @@ unsigned native_patch(u8 type, u16 clobbers, void *ibuf, > PATCH_SITE(pv_irq_ops, save_fl); > PATCH_SITE(pv_irq_ops, irq_enable); > PATCH_SITE(pv_irq_ops, irq_disable); > - PATCH_SITE(pv_cpu_ops, irq_enable_sysexit); > PATCH_SITE(pv_cpu_ops, usergs_sysret32); > PATCH_SITE(pv_cpu_ops, usergs_sysret64); > PATCH_SITE(pv_cpu_ops, swapgs); > diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c > index 81665c9f2132..3797b6b31f95 100644 > --- a/arch/x86/xen/enlighten.c > +++ b/arch/x86/xen/enlighten.c > @@ -1267,10 +1267,11 @@ static const struct pv_cpu_ops xen_cpu_ops __initconst = { > .read_tscp = native_read_tscp, > > .iret = xen_iret, > - .irq_enable_sysexit = xen_sysexit, > #ifdef CONFIG_X86_64 > .usergs_sysret32 = xen_sysret32, > .usergs_sysret64 = xen_sysret64, > +#else > + .irq_enable_sysexit = xen_sysexit, > #endif > > .load_tr_desc = paravirt_nop, > diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S > index 985fc3ee0973..a2cabb8bd6bf 100644 > --- a/arch/x86/xen/xen-asm_64.S > +++ b/arch/x86/xen/xen-asm_64.S > @@ -47,22 +47,6 @@ ENTRY(xen_iret) > ENDPATCH(xen_iret) > RELOC(xen_iret, 1b+1) > > -/* > - * sysexit is not used for 64-bit processes, so it's only ever used to > - * return to 32-bit compat userspace. > - */ > -ENTRY(xen_sysexit) > - pushq $__USER32_DS > - pushq %rcx > - pushq $X86_EFLAGS_IF > - pushq $__USER32_CS > - pushq %rdx > - > - pushq $0 > -1: jmp hypercall_iret > -ENDPATCH(xen_sysexit) > -RELOC(xen_sysexit, 1b+1) > - > ENTRY(xen_sysret64) > /* > * We're already on the usermode stack at this point, but > diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h > index 9e195c683549..c20fe29e65f4 100644 > --- a/arch/x86/xen/xen-ops.h > +++ b/arch/x86/xen/xen-ops.h > @@ -134,7 +134,9 @@ DECL_ASM(void, xen_restore_fl_direct, unsigned long); > > /* These are not functions, and cannot be called normally */ > __visible void xen_iret(void); > +#ifdef CONFIG_X86_32 > __visible void xen_sysexit(void); > +#endif > __visible void xen_sysret32(void); > __visible void xen_sysret64(void); > __visible void xen_adjust_exception_frame(void); > -- > 2.3.0 > -- Andy Lutomirski AMA Capital Management, LLC -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/