From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757355Ab0IUCca (ORCPT ); Mon, 20 Sep 2010 22:32:30 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:38417 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755203Ab0IUCc3 (ORCPT ); Mon, 20 Sep 2010 22:32:29 -0400 X-Authority-Analysis: v=1.1 cv=QPMnOuvfoRK4nyqTv0NRvva4Xk0fUUuJArrqv1I9dZo= c=1 sm=0 a=Ci446elm3-IA:10 a=Q9fys5e9bTEA:10 a=OPBmh+XkhLl+Enan7BmTLg==:17 a=20KFwNOVAAAA:8 a=-QP0a65oMocZ6gWoyh8A:9 a=1vm0Enzo11fQesiRpK0A:7 a=V70aUSl3z5LqXSM-JrdfEzmDi6gA:4 a=PUjeQqilurYA:10 a=jEp0ucaQiEUA:10 a=OPBmh+XkhLl+Enan7BmTLg==:117 X-Cloudmark-Score: 0 X-Originating-IP: 67.242.120.143 Subject: Re: [PATCH 08/10] jump label v11: x86 support From: Steven Rostedt To: Jason Baron Cc: linux-kernel@vger.kernel.org, mingo@elte.hu, mathieu.desnoyers@polymtl.ca, hpa@zytor.com, tglx@linutronix.de, andi@firstfloor.org, roland@redhat.com, rth@redhat.com, mhiramat@redhat.com, fweisbec@gmail.com, avi@redhat.com, davem@davemloft.net, vgoyal@redhat.com, sam@ravnborg.org, tony@bakeyournoodle.com In-Reply-To: References: Content-Type: text/plain; charset="ISO-8859-15" Date: Mon, 20 Sep 2010 22:32:26 -0400 Message-ID: <1285036346.23122.1117.camel@gandalf.stny.rr.com> Mime-Version: 1.0 X-Mailer: Evolution 2.30.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I'm starting to play with this. I just updated my distcc to gcc 4.5.1 so that I can. On Fri, 2010-09-17 at 11:09 -0400, Jason Baron wrote: > add x86 support for jump label. I'm keeping this patch separate so its clear to > arch maintainers what was required for x86 support this new feature. hopefully, > it wouldn't be too painful for other arches. > > Signed-off-by: Jason Baron > --- > arch/x86/Kconfig | 1 + > arch/x86/include/asm/jump_label.h | 47 +++++++++++++++++++++++++++++++++++ > arch/x86/kernel/Makefile | 2 +- > arch/x86/kernel/jump_label.c | 49 +++++++++++++++++++++++++++++++++++++ > arch/x86/kernel/module.c | 3 ++ > 5 files changed, 101 insertions(+), 1 deletions(-) > create mode 100644 arch/x86/include/asm/jump_label.h > create mode 100644 arch/x86/kernel/jump_label.c > > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index 0c14369..a986079 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -60,6 +60,7 @@ config X86 > select ANON_INODES > select HAVE_ARCH_KMEMCHECK > select HAVE_USER_RETURN_NOTIFIER > + select HAVE_ARCH_JUMP_LABEL if !CC_OPTIMIZE_FOR_SIZE > > config INSTRUCTION_DECODER > def_bool (KPROBES || PERF_EVENTS) > diff --git a/arch/x86/include/asm/jump_label.h b/arch/x86/include/asm/jump_label.h > new file mode 100644 > index 0000000..b4a2cb4 > --- /dev/null > +++ b/arch/x86/include/asm/jump_label.h > @@ -0,0 +1,47 @@ > +#ifndef _ASM_X86_JUMP_LABEL_H > +#define _ASM_X86_JUMP_LABEL_H > + > +#ifdef __KERNEL__ > + > +#include > +#include > + > +#define JUMP_LABEL_NOP_SIZE 5 > + > +# define JUMP_LABEL_INITIAL_NOP ".byte 0xe9 \n\t .long 0\n\t" > + > +# define JUMP_LABEL(key, label) \ > + do { \ > + asm goto("1:" \ > + JUMP_LABEL_INITIAL_NOP \ > + ".pushsection __jump_table, \"a\" \n\t"\ > + _ASM_PTR "1b, %l[" #label "], %c0 \n\t" \ > + ".popsection \n\t" \ > + : : "i" (key) : : label); \ > + } while (0) > + > +#endif /* __KERNEL__ */ > + > +#ifdef CONFIG_X86_64 > + > +typedef u64 jump_label_t; > + > +struct jump_entry { > + jump_label_t code; > + jump_label_t target; > + jump_label_t key; > +}; > + > +#else > + > +typedef u32 jump_label_t; > + > +struct jump_entry { > + jump_label_t code; > + jump_label_t target; > + jump_label_t key; > +}; > + > +#endif Why duplicate the structure? You typedef'd jump_label_t and used that in the structure twice! -- Steve > + > +#endif > diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile > index 11a9925..dfa1443 100644 > --- a/arch/x86/kernel/Makefile > +++ b/arch/x86/kernel/Makefile > @@ -32,7 +32,7 @@ GCOV_PROFILE_paravirt.o := n > obj-y := process_$(BITS).o signal.o entry_$(BITS).o > obj-y += traps.o irq.o irq_$(BITS).o dumpstack_$(BITS).o > obj-y += time.o ioport.o ldt.o dumpstack.o > -obj-y += setup.o x86_init.o i8259.o irqinit.o > +obj-y += setup.o x86_init.o i8259.o irqinit.o jump_label.o > obj-$(CONFIG_X86_VISWS) += visws_quirks.o > obj-$(CONFIG_X86_32) += probe_roms_32.o > obj-$(CONFIG_X86_32) += sys_i386_32.o i386_ksyms_32.o > diff --git a/arch/x86/kernel/jump_label.c b/arch/x86/kernel/jump_label.c > new file mode 100644 > index 0000000..b3c0f37 > --- /dev/null > +++ b/arch/x86/kernel/jump_label.c > @@ -0,0 +1,49 @@ > +/* > + * jump label x86 support > + * > + * Copyright (C) 2009 Jason Baron > + * > + */ > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#ifdef HAVE_JUMP_LABEL > + > +union jump_code_union { > + char code[JUMP_LABEL_NOP_SIZE]; > + struct { > + char jump; > + int offset; > + } __attribute__((packed)); > +}; > + > +void arch_jump_label_transform(struct jump_entry *entry, enum jump_label_type type) > +{ > + union jump_code_union code; > + > + if (type == JUMP_LABEL_ENABLE) { > + code.jump = 0xe9; > + code.offset = entry->target - > + (entry->code + JUMP_LABEL_NOP_SIZE); > + } else > + memcpy(&code, ideal_nop5, JUMP_LABEL_NOP_SIZE); > + get_online_cpus(); > + mutex_lock(&text_mutex); > + text_poke_smp((void *)entry->code, &code, JUMP_LABEL_NOP_SIZE); > + mutex_unlock(&text_mutex); > + put_online_cpus(); > +} > + > +void arch_jump_label_text_poke_early(jump_label_t addr) > +{ > + text_poke_early((void *)addr, ideal_nop5, JUMP_LABEL_NOP_SIZE); > +} > + > +#endif > diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c > index e0bc186..5399f58 100644 > --- a/arch/x86/kernel/module.c > +++ b/arch/x86/kernel/module.c > @@ -239,6 +239,9 @@ int module_finalize(const Elf_Ehdr *hdr, > apply_paravirt(pseg, pseg + para->sh_size); > } > > + /* make jump label nops */ > + jump_label_apply_nops(me); > + > return module_bug_finalize(hdr, sechdrs, me); > } >