From: Masahiro Yamada yamada.masahiro@socionext.com
commit e9666d10a5677a494260d60d1fa0b73cc7646eb3 upstream.
Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label".
The jump label is controlled by HAVE_JUMP_LABEL, which is defined like this:
#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL) # define HAVE_JUMP_LABEL #endif
We can improve this by testing 'asm goto' support in Kconfig, then make JUMP_LABEL depend on CC_HAS_ASM_GOTO.
Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will match to the real kernel capability.
Signed-off-by: Masahiro Yamada yamada.masahiro@socionext.com Acked-by: Michael Ellerman mpe@ellerman.id.au (powerpc) Tested-by: Sedat Dilek sedat.dilek@gmail.com [nc: Fix trivial conflicts in 4.19 arch/xtensa/kernel/jump_label.c doesn't exist yet Ensured CC_HAVE_ASM_GOTO and HAVE_JUMP_LABEL were sufficiently eliminated] Signed-off-by: Nathan Chancellor natechancellor@gmail.com ---
Hi Greg and Sasha,
Please pick up this patch for 4.19. It fixes some warnings in the boot code for x86 when using clang because that Makefile steamrolls KBUILD_CFLAGS so CC_HAVE_ASM_GOTO is not defined, which triggers the warnings in arch/x86/include/asm/cpufeature.h on line 143.
I've tested this with GCC 9.1.0 and a clang 9.0.0 build with asm goto support on arm, arm64, and x86_64 and CONFIG_CC_HAS_ASM_GOTO and CONFIG_JUMP_LABEL get enabled properly.
Makefile | 7 ------ arch/Kconfig | 1 + arch/arm/kernel/jump_label.c | 4 ---- arch/arm64/kernel/jump_label.c | 4 ---- arch/mips/kernel/jump_label.c | 4 ---- arch/powerpc/include/asm/asm-prototypes.h | 2 +- arch/powerpc/kernel/jump_label.c | 2 -- .../platforms/powernv/opal-tracepoints.c | 2 +- .../powerpc/platforms/powernv/opal-wrappers.S | 2 +- arch/powerpc/platforms/pseries/hvCall.S | 4 ++-- arch/powerpc/platforms/pseries/lpar.c | 2 +- arch/s390/kernel/Makefile | 3 ++- arch/s390/kernel/jump_label.c | 4 ---- arch/sparc/kernel/Makefile | 2 +- arch/sparc/kernel/jump_label.c | 4 ---- arch/x86/Makefile | 2 +- arch/x86/entry/calling.h | 2 +- arch/x86/include/asm/cpufeature.h | 2 +- arch/x86/include/asm/jump_label.h | 13 ----------- arch/x86/include/asm/rmwcc.h | 6 ++--- arch/x86/kernel/Makefile | 3 ++- arch/x86/kernel/jump_label.c | 4 ---- arch/x86/kvm/emulate.c | 2 +- include/linux/dynamic_debug.h | 6 ++--- include/linux/jump_label.h | 22 ++++++++----------- include/linux/jump_label_ratelimit.h | 8 +++---- include/linux/module.h | 2 +- include/linux/netfilter.h | 4 ++-- include/linux/netfilter_ingress.h | 2 +- init/Kconfig | 3 +++ kernel/jump_label.c | 10 +++------ kernel/module.c | 2 +- kernel/sched/core.c | 2 +- kernel/sched/debug.c | 4 ++-- kernel/sched/fair.c | 6 ++--- kernel/sched/sched.h | 6 ++--- lib/dynamic_debug.c | 2 +- net/core/dev.c | 6 ++--- net/netfilter/core.c | 6 ++--- scripts/gcc-goto.sh | 2 +- tools/arch/x86/include/asm/rmwcc.h | 6 ++--- 41 files changed, 65 insertions(+), 115 deletions(-)
diff --git a/Makefile b/Makefile index 5383dd317d59..ec326417527a 100644 --- a/Makefile +++ b/Makefile @@ -508,13 +508,6 @@ export RETPOLINE_VDSO_CFLAGS KBUILD_CFLAGS += $(call cc-option,-fno-PIE) KBUILD_AFLAGS += $(call cc-option,-fno-PIE)
-# check for 'asm goto' -ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC) $(KBUILD_CFLAGS)), y) - CC_HAVE_ASM_GOTO := 1 - KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTO - KBUILD_AFLAGS += -DCC_HAVE_ASM_GOTO -endif - # The expansion should be delayed until arch/$(SRCARCH)/Makefile is included. # Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile. # CC_VERSION_TEXT is referenced from Kconfig (so it needs export), diff --git a/arch/Kconfig b/arch/Kconfig index 6801123932a5..a336548487e6 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -71,6 +71,7 @@ config KPROBES config JUMP_LABEL bool "Optimize very unlikely/likely branches" depends on HAVE_ARCH_JUMP_LABEL + depends on CC_HAS_ASM_GOTO help This option enables a transparent branch optimization that makes certain almost-always-true or almost-always-false branch diff --git a/arch/arm/kernel/jump_label.c b/arch/arm/kernel/jump_label.c index 90bce3d9928e..303b3ab87f7e 100644 --- a/arch/arm/kernel/jump_label.c +++ b/arch/arm/kernel/jump_label.c @@ -4,8 +4,6 @@ #include <asm/patch.h> #include <asm/insn.h>
-#ifdef HAVE_JUMP_LABEL - static void __arch_jump_label_transform(struct jump_entry *entry, enum jump_label_type type, bool is_static) @@ -35,5 +33,3 @@ void arch_jump_label_transform_static(struct jump_entry *entry, { __arch_jump_label_transform(entry, type, true); } - -#endif diff --git a/arch/arm64/kernel/jump_label.c b/arch/arm64/kernel/jump_label.c index e0756416e567..b90754aebd12 100644 --- a/arch/arm64/kernel/jump_label.c +++ b/arch/arm64/kernel/jump_label.c @@ -20,8 +20,6 @@ #include <linux/jump_label.h> #include <asm/insn.h>
-#ifdef HAVE_JUMP_LABEL - void arch_jump_label_transform(struct jump_entry *entry, enum jump_label_type type) { @@ -49,5 +47,3 @@ void arch_jump_label_transform_static(struct jump_entry *entry, * NOP needs to be replaced by a branch. */ } - -#endif /* HAVE_JUMP_LABEL */ diff --git a/arch/mips/kernel/jump_label.c b/arch/mips/kernel/jump_label.c index 32e3168316cd..ab943927f97a 100644 --- a/arch/mips/kernel/jump_label.c +++ b/arch/mips/kernel/jump_label.c @@ -16,8 +16,6 @@ #include <asm/cacheflush.h> #include <asm/inst.h>
-#ifdef HAVE_JUMP_LABEL - /* * Define parameters for the standard MIPS and the microMIPS jump * instruction encoding respectively: @@ -70,5 +68,3 @@ void arch_jump_label_transform(struct jump_entry *e,
mutex_unlock(&text_mutex); } - -#endif /* HAVE_JUMP_LABEL */ diff --git a/arch/powerpc/include/asm/asm-prototypes.h b/arch/powerpc/include/asm/asm-prototypes.h index 1f4691ce4126..e398173ae67d 100644 --- a/arch/powerpc/include/asm/asm-prototypes.h +++ b/arch/powerpc/include/asm/asm-prototypes.h @@ -38,7 +38,7 @@ extern struct static_key hcall_tracepoint_key; void __trace_hcall_entry(unsigned long opcode, unsigned long *args); void __trace_hcall_exit(long opcode, long retval, unsigned long *retbuf); /* OPAL tracing */ -#ifdef HAVE_JUMP_LABEL +#ifdef CONFIG_JUMP_LABEL extern struct static_key opal_tracepoint_key; #endif
diff --git a/arch/powerpc/kernel/jump_label.c b/arch/powerpc/kernel/jump_label.c index 6472472093d0..0080c5fbd225 100644 --- a/arch/powerpc/kernel/jump_label.c +++ b/arch/powerpc/kernel/jump_label.c @@ -11,7 +11,6 @@ #include <linux/jump_label.h> #include <asm/code-patching.h>
-#ifdef HAVE_JUMP_LABEL void arch_jump_label_transform(struct jump_entry *entry, enum jump_label_type type) { @@ -22,4 +21,3 @@ void arch_jump_label_transform(struct jump_entry *entry, else patch_instruction(addr, PPC_INST_NOP); } -#endif diff --git a/arch/powerpc/platforms/powernv/opal-tracepoints.c b/arch/powerpc/platforms/powernv/opal-tracepoints.c index 1ab7d26c0a2c..f16a43540e30 100644 --- a/arch/powerpc/platforms/powernv/opal-tracepoints.c +++ b/arch/powerpc/platforms/powernv/opal-tracepoints.c @@ -4,7 +4,7 @@ #include <asm/trace.h> #include <asm/asm-prototypes.h>
-#ifdef HAVE_JUMP_LABEL +#ifdef CONFIG_JUMP_LABEL struct static_key opal_tracepoint_key = STATIC_KEY_INIT;
int opal_tracepoint_regfunc(void) diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S index 251528231a9e..f4875fe3f8ff 100644 --- a/arch/powerpc/platforms/powernv/opal-wrappers.S +++ b/arch/powerpc/platforms/powernv/opal-wrappers.S @@ -20,7 +20,7 @@ .section ".text"
#ifdef CONFIG_TRACEPOINTS -#ifdef HAVE_JUMP_LABEL +#ifdef CONFIG_JUMP_LABEL #define OPAL_BRANCH(LABEL) \ ARCH_STATIC_BRANCH(LABEL, opal_tracepoint_key) #else diff --git a/arch/powerpc/platforms/pseries/hvCall.S b/arch/powerpc/platforms/pseries/hvCall.S index d91412c591ef..50dc9426d0be 100644 --- a/arch/powerpc/platforms/pseries/hvCall.S +++ b/arch/powerpc/platforms/pseries/hvCall.S @@ -19,7 +19,7 @@ #ifdef CONFIG_TRACEPOINTS
-#ifndef HAVE_JUMP_LABEL +#ifndef CONFIG_JUMP_LABEL .section ".toc","aw"
.globl hcall_tracepoint_refcount @@ -79,7 +79,7 @@ hcall_tracepoint_refcount: mr r5,BUFREG; \ __HCALL_INST_POSTCALL
-#ifdef HAVE_JUMP_LABEL +#ifdef CONFIG_JUMP_LABEL #define HCALL_BRANCH(LABEL) \ ARCH_STATIC_BRANCH(LABEL, hcall_tracepoint_key) #else diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c index d3992ced0782..9e52b686a8fa 100644 --- a/arch/powerpc/platforms/pseries/lpar.c +++ b/arch/powerpc/platforms/pseries/lpar.c @@ -828,7 +828,7 @@ EXPORT_SYMBOL(arch_free_page); #endif /* CONFIG_PPC_BOOK3S_64 */
#ifdef CONFIG_TRACEPOINTS -#ifdef HAVE_JUMP_LABEL +#ifdef CONFIG_JUMP_LABEL struct static_key hcall_tracepoint_key = STATIC_KEY_INIT;
int hcall_tracepoint_regfunc(void) diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile index dbfd1730e631..b205c0ff0b22 100644 --- a/arch/s390/kernel/Makefile +++ b/arch/s390/kernel/Makefile @@ -44,7 +44,7 @@ CFLAGS_ptrace.o += -DUTS_MACHINE='"$(UTS_MACHINE)"' obj-y := traps.o time.o process.o base.o early.o setup.o idle.o vtime.o obj-y += processor.o sys_s390.o ptrace.o signal.o cpcmd.o ebcdic.o nmi.o obj-y += debug.o irq.o ipl.o dis.o diag.o vdso.o early_nobss.o -obj-y += sysinfo.o jump_label.o lgr.o os_info.o machine_kexec.o pgm_check.o +obj-y += sysinfo.o lgr.o os_info.o machine_kexec.o pgm_check.o obj-y += runtime_instr.o cache.o fpu.o dumpstack.o guarded_storage.o sthyi.o obj-y += entry.o reipl.o relocate_kernel.o kdebugfs.o alternative.o obj-y += nospec-branch.o @@ -68,6 +68,7 @@ obj-$(CONFIG_KPROBES) += kprobes.o obj-$(CONFIG_FUNCTION_TRACER) += mcount.o ftrace.o obj-$(CONFIG_CRASH_DUMP) += crash_dump.o obj-$(CONFIG_UPROBES) += uprobes.o +obj-$(CONFIG_JUMP_LABEL) += jump_label.o
obj-$(CONFIG_KEXEC_FILE) += machine_kexec_file.o kexec_image.o obj-$(CONFIG_KEXEC_FILE) += kexec_elf.o diff --git a/arch/s390/kernel/jump_label.c b/arch/s390/kernel/jump_label.c index 43f8430fb67d..68f415e334a5 100644 --- a/arch/s390/kernel/jump_label.c +++ b/arch/s390/kernel/jump_label.c @@ -10,8 +10,6 @@ #include <linux/jump_label.h> #include <asm/ipl.h>
-#ifdef HAVE_JUMP_LABEL - struct insn { u16 opcode; s32 offset; @@ -102,5 +100,3 @@ void arch_jump_label_transform_static(struct jump_entry *entry, { __jump_label_transform(entry, type, 1); } - -#endif diff --git a/arch/sparc/kernel/Makefile b/arch/sparc/kernel/Makefile index cf8640841b7a..97c0e19263d1 100644 --- a/arch/sparc/kernel/Makefile +++ b/arch/sparc/kernel/Makefile @@ -118,4 +118,4 @@ pc--$(CONFIG_PERF_EVENTS) := perf_event.o obj-$(CONFIG_SPARC64) += $(pc--y)
obj-$(CONFIG_UPROBES) += uprobes.o -obj-$(CONFIG_SPARC64) += jump_label.o +obj-$(CONFIG_JUMP_LABEL) += jump_label.o diff --git a/arch/sparc/kernel/jump_label.c b/arch/sparc/kernel/jump_label.c index 7f8eac51df33..a4cfaeecaf5e 100644 --- a/arch/sparc/kernel/jump_label.c +++ b/arch/sparc/kernel/jump_label.c @@ -9,8 +9,6 @@
#include <asm/cacheflush.h>
-#ifdef HAVE_JUMP_LABEL - void arch_jump_label_transform(struct jump_entry *entry, enum jump_label_type type) { @@ -47,5 +45,3 @@ void arch_jump_label_transform(struct jump_entry *entry, flushi(insn); mutex_unlock(&text_mutex); } - -#endif diff --git a/arch/x86/Makefile b/arch/x86/Makefile index ffc823a8312f..022d30768a92 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -305,7 +305,7 @@ vdso_install:
archprepare: checkbin checkbin: -ifndef CC_HAVE_ASM_GOTO +ifndef CONFIG_CC_HAS_ASM_GOTO @echo Compiler lacks asm-goto support. @exit 1 endif diff --git a/arch/x86/entry/calling.h b/arch/x86/entry/calling.h index 352e70cd33e8..e699b2041665 100644 --- a/arch/x86/entry/calling.h +++ b/arch/x86/entry/calling.h @@ -337,7 +337,7 @@ For 32-bit we have the following conventions - kernel is built with */ .macro CALL_enter_from_user_mode #ifdef CONFIG_CONTEXT_TRACKING -#ifdef HAVE_JUMP_LABEL +#ifdef CONFIG_JUMP_LABEL STATIC_JUMP_IF_FALSE .Lafter_call_@, context_tracking_enabled, def=0 #endif call enter_from_user_mode diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index aced6c9290d6..ce95b8cbd229 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -140,7 +140,7 @@ extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit);
#define setup_force_cpu_bug(bit) setup_force_cpu_cap(bit)
-#if defined(__clang__) && !defined(CC_HAVE_ASM_GOTO) +#if defined(__clang__) && !defined(CONFIG_CC_HAS_ASM_GOTO)
/* * Workaround for the sake of BPF compilation which utilizes kernel diff --git a/arch/x86/include/asm/jump_label.h b/arch/x86/include/asm/jump_label.h index 8c0de4282659..7010e1c594c4 100644 --- a/arch/x86/include/asm/jump_label.h +++ b/arch/x86/include/asm/jump_label.h @@ -2,19 +2,6 @@ #ifndef _ASM_X86_JUMP_LABEL_H #define _ASM_X86_JUMP_LABEL_H
-#ifndef HAVE_JUMP_LABEL -/* - * For better or for worse, if jump labels (the gcc extension) are missing, - * then the entire static branch patching infrastructure is compiled out. - * If that happens, the code in here will malfunction. Raise a compiler - * error instead. - * - * In theory, jump labels and the static branch patching infrastructure - * could be decoupled to fix this. - */ -#error asm/jump_label.h included on a non-jump-label kernel -#endif - #define JUMP_LABEL_NOP_SIZE 5
#ifdef CONFIG_X86_64 diff --git a/arch/x86/include/asm/rmwcc.h b/arch/x86/include/asm/rmwcc.h index 4914a3e7c803..033dc7ca49e9 100644 --- a/arch/x86/include/asm/rmwcc.h +++ b/arch/x86/include/asm/rmwcc.h @@ -4,7 +4,7 @@
#define __CLOBBERS_MEM(clb...) "memory", ## clb
-#if !defined(__GCC_ASM_FLAG_OUTPUTS__) && defined(CC_HAVE_ASM_GOTO) +#if !defined(__GCC_ASM_FLAG_OUTPUTS__) && defined(CONFIG_CC_HAS_ASM_GOTO)
/* Use asm goto */
@@ -21,7 +21,7 @@ cc_label: \ #define __BINARY_RMWcc_ARG " %1, "
-#else /* defined(__GCC_ASM_FLAG_OUTPUTS__) || !defined(CC_HAVE_ASM_GOTO) */ +#else /* defined(__GCC_ASM_FLAG_OUTPUTS__) || !defined(CONFIG_CC_HAS_ASM_GOTO) */
/* Use flags output or a set instruction */
@@ -36,7 +36,7 @@ do { \
#define __BINARY_RMWcc_ARG " %2, "
-#endif /* defined(__GCC_ASM_FLAG_OUTPUTS__) || !defined(CC_HAVE_ASM_GOTO) */ +#endif /* defined(__GCC_ASM_FLAG_OUTPUTS__) || !defined(CONFIG_CC_HAS_ASM_GOTO) */
#define GEN_UNARY_RMWcc(op, var, arg0, cc) \ __GEN_RMWcc(op " " arg0, var, cc, __CLOBBERS_MEM()) diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 8824d01c0c35..da0b6bc090f3 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -49,7 +49,8 @@ obj-$(CONFIG_COMPAT) += signal_compat.o obj-y += traps.o idt.o irq.o irq_$(BITS).o dumpstack_$(BITS).o obj-y += time.o ioport.o dumpstack.o nmi.o obj-$(CONFIG_MODIFY_LDT_SYSCALL) += ldt.o -obj-y += setup.o x86_init.o i8259.o irqinit.o jump_label.o +obj-y += setup.o x86_init.o i8259.o irqinit.o +obj-$(CONFIG_JUMP_LABEL) += jump_label.o obj-$(CONFIG_IRQ_WORK) += irq_work.o obj-y += probe_roms.o obj-$(CONFIG_X86_64) += sys_x86_64.o diff --git a/arch/x86/kernel/jump_label.c b/arch/x86/kernel/jump_label.c index eeea935e9bb5..4c3d9a3d45b2 100644 --- a/arch/x86/kernel/jump_label.c +++ b/arch/x86/kernel/jump_label.c @@ -16,8 +16,6 @@ #include <asm/alternative.h> #include <asm/text-patching.h>
-#ifdef HAVE_JUMP_LABEL - union jump_code_union { char code[JUMP_LABEL_NOP_SIZE]; struct { @@ -142,5 +140,3 @@ __init_or_module void arch_jump_label_transform_static(struct jump_entry *entry, if (jlstate == JL_STATE_UPDATE) __jump_label_transform(entry, type, text_poke_early, 1); } - -#endif diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 860bd271619d..4a688ef9e448 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -456,7 +456,7 @@ FOP_END;
/* * XXX: inoutclob user must know where the argument is being expanded. - * Relying on CC_HAVE_ASM_GOTO would allow us to remove _fault. + * Relying on CONFIG_CC_HAS_ASM_GOTO would allow us to remove _fault. */ #define asm_safe(insn, inoutclob...) \ ({ \ diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h index 2fd8006153c3..b3419da1a776 100644 --- a/include/linux/dynamic_debug.h +++ b/include/linux/dynamic_debug.h @@ -2,7 +2,7 @@ #ifndef _DYNAMIC_DEBUG_H #define _DYNAMIC_DEBUG_H
-#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL) +#if defined(CONFIG_JUMP_LABEL) #include <linux/jump_label.h> #endif
@@ -38,7 +38,7 @@ struct _ddebug { #define _DPRINTK_FLAGS_DEFAULT 0 #endif unsigned int flags:8; -#ifdef HAVE_JUMP_LABEL +#ifdef CONFIG_JUMP_LABEL union { struct static_key_true dd_key_true; struct static_key_false dd_key_false; @@ -83,7 +83,7 @@ void __dynamic_netdev_dbg(struct _ddebug *descriptor, dd_key_init(key, init) \ }
-#ifdef HAVE_JUMP_LABEL +#ifdef CONFIG_JUMP_LABEL
#define dd_key_init(key, init) key = (init)
diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h index 1a0b6f17a5d6..4c3e77687d4e 100644 --- a/include/linux/jump_label.h +++ b/include/linux/jump_label.h @@ -71,10 +71,6 @@ * Additional babbling in: Documentation/static-keys.txt */
-#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL) -# define HAVE_JUMP_LABEL -#endif - #ifndef __ASSEMBLY__
#include <linux/types.h> @@ -86,7 +82,7 @@ extern bool static_key_initialized; "%s(): static key '%pS' used before call to jump_label_init()", \ __func__, (key))
-#ifdef HAVE_JUMP_LABEL +#ifdef CONFIG_JUMP_LABEL
struct static_key { atomic_t enabled; @@ -114,10 +110,10 @@ struct static_key { struct static_key { atomic_t enabled; }; -#endif /* HAVE_JUMP_LABEL */ +#endif /* CONFIG_JUMP_LABEL */ #endif /* __ASSEMBLY__ */
-#ifdef HAVE_JUMP_LABEL +#ifdef CONFIG_JUMP_LABEL #include <asm/jump_label.h> #endif
@@ -130,7 +126,7 @@ enum jump_label_type {
struct module;
-#ifdef HAVE_JUMP_LABEL +#ifdef CONFIG_JUMP_LABEL
#define JUMP_TYPE_FALSE 0UL #define JUMP_TYPE_TRUE 1UL @@ -184,7 +180,7 @@ extern void static_key_disable_cpuslocked(struct static_key *key); { .enabled = { 0 }, \ { .entries = (void *)JUMP_TYPE_FALSE } }
-#else /* !HAVE_JUMP_LABEL */ +#else /* !CONFIG_JUMP_LABEL */
#include <linux/atomic.h> #include <linux/bug.h> @@ -271,7 +267,7 @@ static inline void static_key_disable(struct static_key *key) #define STATIC_KEY_INIT_TRUE { .enabled = ATOMIC_INIT(1) } #define STATIC_KEY_INIT_FALSE { .enabled = ATOMIC_INIT(0) }
-#endif /* HAVE_JUMP_LABEL */ +#endif /* CONFIG_JUMP_LABEL */
#define STATIC_KEY_INIT STATIC_KEY_INIT_FALSE #define jump_label_enabled static_key_enabled @@ -335,7 +331,7 @@ extern bool ____wrong_branch_error(void); static_key_count((struct static_key *)x) > 0; \ })
-#ifdef HAVE_JUMP_LABEL +#ifdef CONFIG_JUMP_LABEL
/* * Combine the right initial value (type) with the right branch order @@ -417,12 +413,12 @@ extern bool ____wrong_branch_error(void); unlikely(branch); \ })
-#else /* !HAVE_JUMP_LABEL */ +#else /* !CONFIG_JUMP_LABEL */
#define static_branch_likely(x) likely(static_key_enabled(&(x)->key)) #define static_branch_unlikely(x) unlikely(static_key_enabled(&(x)->key))
-#endif /* HAVE_JUMP_LABEL */ +#endif /* CONFIG_JUMP_LABEL */
/* * Advanced usage; refcount, branch is enabled when: count != 0 diff --git a/include/linux/jump_label_ratelimit.h b/include/linux/jump_label_ratelimit.h index baa8eabbaa56..a49f2b45b3f0 100644 --- a/include/linux/jump_label_ratelimit.h +++ b/include/linux/jump_label_ratelimit.h @@ -5,21 +5,19 @@ #include <linux/jump_label.h> #include <linux/workqueue.h>
-#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL) +#if defined(CONFIG_JUMP_LABEL) struct static_key_deferred { struct static_key key; unsigned long timeout; struct delayed_work work; }; -#endif
-#ifdef HAVE_JUMP_LABEL extern void static_key_slow_dec_deferred(struct static_key_deferred *key); extern void static_key_deferred_flush(struct static_key_deferred *key); extern void jump_label_rate_limit(struct static_key_deferred *key, unsigned long rl);
-#else /* !HAVE_JUMP_LABEL */ +#else /* !CONFIG_JUMP_LABEL */ struct static_key_deferred { struct static_key key; }; @@ -38,5 +36,5 @@ jump_label_rate_limit(struct static_key_deferred *key, { STATIC_KEY_CHECK_USE(key); } -#endif /* HAVE_JUMP_LABEL */ +#endif /* CONFIG_JUMP_LABEL */ #endif /* _LINUX_JUMP_LABEL_RATELIMIT_H */ diff --git a/include/linux/module.h b/include/linux/module.h index 904f94628132..c71044644979 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -433,7 +433,7 @@ struct module { unsigned int num_tracepoints; tracepoint_ptr_t *tracepoints_ptrs; #endif -#ifdef HAVE_JUMP_LABEL +#ifdef CONFIG_JUMP_LABEL struct jump_entry *jump_entries; unsigned int num_jump_entries; #endif diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h index bbe99d2b28b4..72cb19c3db6a 100644 --- a/include/linux/netfilter.h +++ b/include/linux/netfilter.h @@ -176,7 +176,7 @@ void nf_unregister_net_hooks(struct net *net, const struct nf_hook_ops *reg, int nf_register_sockopt(struct nf_sockopt_ops *reg); void nf_unregister_sockopt(struct nf_sockopt_ops *reg);
-#ifdef HAVE_JUMP_LABEL +#ifdef CONFIG_JUMP_LABEL extern struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS]; #endif
@@ -198,7 +198,7 @@ static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net, struct nf_hook_entries *hook_head = NULL; int ret = 1;
-#ifdef HAVE_JUMP_LABEL +#ifdef CONFIG_JUMP_LABEL if (__builtin_constant_p(pf) && __builtin_constant_p(hook) && !static_key_false(&nf_hooks_needed[pf][hook])) diff --git a/include/linux/netfilter_ingress.h b/include/linux/netfilter_ingress.h index 554c920691dd..a13774be2eb5 100644 --- a/include/linux/netfilter_ingress.h +++ b/include/linux/netfilter_ingress.h @@ -8,7 +8,7 @@ #ifdef CONFIG_NETFILTER_INGRESS static inline bool nf_hook_ingress_active(const struct sk_buff *skb) { -#ifdef HAVE_JUMP_LABEL +#ifdef CONFIG_JUMP_LABEL if (!static_key_false(&nf_hooks_needed[NFPROTO_NETDEV][NF_NETDEV_INGRESS])) return false; #endif diff --git a/init/Kconfig b/init/Kconfig index 864af10bb1b9..47035b5a46f6 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -23,6 +23,9 @@ config CLANG_VERSION int default $(shell,$(srctree)/scripts/clang-version.sh $(CC))
+config CC_HAS_ASM_GOTO + def_bool $(success,$(srctree)/scripts/gcc-goto.sh $(CC)) + config CONSTRUCTORS bool depends on !UML diff --git a/kernel/jump_label.c b/kernel/jump_label.c index 2e62503bea0d..7c8262635b29 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -18,8 +18,6 @@ #include <linux/cpu.h> #include <asm/sections.h>
-#ifdef HAVE_JUMP_LABEL - /* mutex to protect coming/going of the the jump_label table */ static DEFINE_MUTEX(jump_label_mutex);
@@ -60,13 +58,13 @@ jump_label_sort_entries(struct jump_entry *start, struct jump_entry *stop) static void jump_label_update(struct static_key *key);
/* - * There are similar definitions for the !HAVE_JUMP_LABEL case in jump_label.h. + * There are similar definitions for the !CONFIG_JUMP_LABEL case in jump_label.h. * The use of 'atomic_read()' requires atomic.h and its problematic for some * kernel headers such as kernel.h and others. Since static_key_count() is not - * used in the branch statements as it is for the !HAVE_JUMP_LABEL case its ok + * used in the branch statements as it is for the !CONFIG_JUMP_LABEL case its ok * to have it be a function here. Similarly, for 'static_key_enable()' and * 'static_key_disable()', which require bug.h. This should allow jump_label.h - * to be included from most/all places for HAVE_JUMP_LABEL. + * to be included from most/all places for CONFIG_JUMP_LABEL. */ int static_key_count(struct static_key *key) { @@ -796,5 +794,3 @@ static __init int jump_label_test(void) } early_initcall(jump_label_test); #endif /* STATIC_KEYS_SELFTEST */ - -#endif /* HAVE_JUMP_LABEL */ diff --git a/kernel/module.c b/kernel/module.c index 38bf28b5cc20..c1d59a90491d 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -3095,7 +3095,7 @@ static int find_module_sections(struct module *mod, struct load_info *info) sizeof(*mod->tracepoints_ptrs), &mod->num_tracepoints); #endif -#ifdef HAVE_JUMP_LABEL +#ifdef CONFIG_JUMP_LABEL mod->jump_entries = section_objs(info, "__jump_table", sizeof(*mod->jump_entries), &mod->num_jump_entries); diff --git a/kernel/sched/core.c b/kernel/sched/core.c index d7f409866cdf..7abb89ab9822 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -24,7 +24,7 @@
DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
-#if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL) +#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_JUMP_LABEL) /* * Debugging: various feature bits * diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index 141ea9ff210e..78fadf0438ea 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -73,7 +73,7 @@ static int sched_feat_show(struct seq_file *m, void *v) return 0; }
-#ifdef HAVE_JUMP_LABEL +#ifdef CONFIG_JUMP_LABEL
#define jump_label_key__true STATIC_KEY_INIT_TRUE #define jump_label_key__false STATIC_KEY_INIT_FALSE @@ -99,7 +99,7 @@ static void sched_feat_enable(int i) #else static void sched_feat_disable(int i) { }; static void sched_feat_enable(int i) { }; -#endif /* HAVE_JUMP_LABEL */ +#endif /* CONFIG_JUMP_LABEL */
static int sched_feat_set(char *cmp) { diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index d31916366d39..a8e72f0ac1c9 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4209,7 +4209,7 @@ entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr, int queued)
#ifdef CONFIG_CFS_BANDWIDTH
-#ifdef HAVE_JUMP_LABEL +#ifdef CONFIG_JUMP_LABEL static struct static_key __cfs_bandwidth_used;
static inline bool cfs_bandwidth_used(void) @@ -4226,7 +4226,7 @@ void cfs_bandwidth_usage_dec(void) { static_key_slow_dec_cpuslocked(&__cfs_bandwidth_used); } -#else /* HAVE_JUMP_LABEL */ +#else /* CONFIG_JUMP_LABEL */ static bool cfs_bandwidth_used(void) { return true; @@ -4234,7 +4234,7 @@ static bool cfs_bandwidth_used(void)
void cfs_bandwidth_usage_inc(void) {} void cfs_bandwidth_usage_dec(void) {} -#endif /* HAVE_JUMP_LABEL */ +#endif /* CONFIG_JUMP_LABEL */
/* * default period for cfs group bandwidth. diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 4c7a837d7c14..9a7c3d08b39f 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1359,7 +1359,7 @@ enum {
#undef SCHED_FEAT
-#if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL) +#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_JUMP_LABEL)
/* * To support run-time toggling of sched features, all the translation units @@ -1379,7 +1379,7 @@ static __always_inline bool static_branch_##name(struct static_key *key) \ extern struct static_key sched_feat_keys[__SCHED_FEAT_NR]; #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x]))
-#else /* !(SCHED_DEBUG && HAVE_JUMP_LABEL) */ +#else /* !(SCHED_DEBUG && CONFIG_JUMP_LABEL) */
/* * Each translation unit has its own copy of sysctl_sched_features to allow @@ -1395,7 +1395,7 @@ static const_debug __maybe_unused unsigned int sysctl_sched_features =
#define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
-#endif /* SCHED_DEBUG && HAVE_JUMP_LABEL */ +#endif /* SCHED_DEBUG && CONFIG_JUMP_LABEL */
extern struct static_key_false sched_numa_balancing; extern struct static_key_false sched_schedstats; diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index c7c96bc7654a..dbf2b457e47e 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -188,7 +188,7 @@ static int ddebug_change(const struct ddebug_query *query, newflags = (dp->flags & mask) | flags; if (newflags == dp->flags) continue; -#ifdef HAVE_JUMP_LABEL +#ifdef CONFIG_JUMP_LABEL if (dp->flags & _DPRINTK_FLAGS_PRINT) { if (!(flags & _DPRINTK_FLAGS_PRINT)) static_branch_disable(&dp->key.dd_key_true); diff --git a/net/core/dev.c b/net/core/dev.c index 13a82744a00a..a71b7f4981f8 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1821,7 +1821,7 @@ EXPORT_SYMBOL_GPL(net_dec_egress_queue); #endif
static DEFINE_STATIC_KEY_FALSE(netstamp_needed_key); -#ifdef HAVE_JUMP_LABEL +#ifdef CONFIG_JUMP_LABEL static atomic_t netstamp_needed_deferred; static atomic_t netstamp_wanted; static void netstamp_clear(struct work_struct *work) @@ -1840,7 +1840,7 @@ static DECLARE_WORK(netstamp_work, netstamp_clear);
void net_enable_timestamp(void) { -#ifdef HAVE_JUMP_LABEL +#ifdef CONFIG_JUMP_LABEL int wanted;
while (1) { @@ -1860,7 +1860,7 @@ EXPORT_SYMBOL(net_enable_timestamp);
void net_disable_timestamp(void) { -#ifdef HAVE_JUMP_LABEL +#ifdef CONFIG_JUMP_LABEL int wanted;
while (1) { diff --git a/net/netfilter/core.c b/net/netfilter/core.c index dc240cb47ddf..93aaec3a54ec 100644 --- a/net/netfilter/core.c +++ b/net/netfilter/core.c @@ -33,7 +33,7 @@ EXPORT_SYMBOL_GPL(nf_ipv6_ops); DEFINE_PER_CPU(bool, nf_skb_duplicated); EXPORT_SYMBOL_GPL(nf_skb_duplicated);
-#ifdef HAVE_JUMP_LABEL +#ifdef CONFIG_JUMP_LABEL struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS]; EXPORT_SYMBOL(nf_hooks_needed); #endif @@ -347,7 +347,7 @@ static int __nf_register_net_hook(struct net *net, int pf, if (pf == NFPROTO_NETDEV && reg->hooknum == NF_NETDEV_INGRESS) net_inc_ingress_queue(); #endif -#ifdef HAVE_JUMP_LABEL +#ifdef CONFIG_JUMP_LABEL static_key_slow_inc(&nf_hooks_needed[pf][reg->hooknum]); #endif BUG_ON(p == new_hooks); @@ -405,7 +405,7 @@ static void __nf_unregister_net_hook(struct net *net, int pf, if (pf == NFPROTO_NETDEV && reg->hooknum == NF_NETDEV_INGRESS) net_dec_ingress_queue(); #endif -#ifdef HAVE_JUMP_LABEL +#ifdef CONFIG_JUMP_LABEL static_key_slow_dec(&nf_hooks_needed[pf][reg->hooknum]); #endif } else { diff --git a/scripts/gcc-goto.sh b/scripts/gcc-goto.sh index 083c526073ef..8b980fb2270a 100755 --- a/scripts/gcc-goto.sh +++ b/scripts/gcc-goto.sh @@ -3,7 +3,7 @@ # Test for gcc 'asm goto' support # Copyright (C) 2010, Jason Baron jbaron@redhat.com
-cat << "END" | $@ -x c - -c -o /dev/null >/dev/null 2>&1 && echo "y" +cat << "END" | $@ -x c - -fno-PIE -c -o /dev/null int main(void) { #if defined(__arm__) || defined(__aarch64__) diff --git a/tools/arch/x86/include/asm/rmwcc.h b/tools/arch/x86/include/asm/rmwcc.h index dc90c0c2fae3..fee7983a90b4 100644 --- a/tools/arch/x86/include/asm/rmwcc.h +++ b/tools/arch/x86/include/asm/rmwcc.h @@ -2,7 +2,7 @@ #ifndef _TOOLS_LINUX_ASM_X86_RMWcc #define _TOOLS_LINUX_ASM_X86_RMWcc
-#ifdef CC_HAVE_ASM_GOTO +#ifdef CONFIG_CC_HAS_ASM_GOTO
#define __GEN_RMWcc(fullop, var, cc, ...) \ do { \ @@ -20,7 +20,7 @@ cc_label: \ #define GEN_BINARY_RMWcc(op, var, vcon, val, arg0, cc) \ __GEN_RMWcc(op " %1, " arg0, var, cc, vcon (val))
-#else /* !CC_HAVE_ASM_GOTO */ +#else /* !CONFIG_CC_HAS_ASM_GOTO */
#define __GEN_RMWcc(fullop, var, cc, ...) \ do { \ @@ -37,6 +37,6 @@ do { \ #define GEN_BINARY_RMWcc(op, var, vcon, val, arg0, cc) \ __GEN_RMWcc(op " %2, " arg0, var, cc, vcon (val))
-#endif /* CC_HAVE_ASM_GOTO */ +#endif /* CONFIG_CC_HAS_ASM_GOTO */
#endif /* _TOOLS_LINUX_ASM_X86_RMWcc */
On Thu, May 30, 2019 at 11:52:00PM -0700, Nathan Chancellor wrote:
From: Masahiro Yamada yamada.masahiro@socionext.com
commit e9666d10a5677a494260d60d1fa0b73cc7646eb3 upstream.
Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label".
The jump label is controlled by HAVE_JUMP_LABEL, which is defined like this:
#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL) # define HAVE_JUMP_LABEL #endif
We can improve this by testing 'asm goto' support in Kconfig, then make JUMP_LABEL depend on CC_HAS_ASM_GOTO.
Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will match to the real kernel capability.
Signed-off-by: Masahiro Yamada yamada.masahiro@socionext.com Acked-by: Michael Ellerman mpe@ellerman.id.au (powerpc) Tested-by: Sedat Dilek sedat.dilek@gmail.com [nc: Fix trivial conflicts in 4.19 arch/xtensa/kernel/jump_label.c doesn't exist yet Ensured CC_HAVE_ASM_GOTO and HAVE_JUMP_LABEL were sufficiently eliminated] Signed-off-by: Nathan Chancellor natechancellor@gmail.com
Hi Greg and Sasha,
Please pick up this patch for 4.19. It fixes some warnings in the boot code for x86 when using clang because that Makefile steamrolls KBUILD_CFLAGS so CC_HAVE_ASM_GOTO is not defined, which triggers the warnings in arch/x86/include/asm/cpufeature.h on line 143.
I've tested this with GCC 9.1.0 and a clang 9.0.0 build with asm goto support on arm, arm64, and x86_64 and CONFIG_CC_HAS_ASM_GOTO and CONFIG_JUMP_LABEL get enabled properly.
Now applied, thanks.
greg k-h
linux-stable-mirror@lists.linaro.org