Re: [PATCH] Fix Immediate Values x86_64 support old gcc (v3)

[Mathieu Desnoyers]

* Mathieu Desnoyers (compudj@xxxxxxxxxxxxxxxxxx) wrote:
> GCC < 4, on x86_64, does not accept symbol+offset operands for "i" constraints
> asm statements. Fallback on generic immediate values if this compiler is
> detected.
> 

Please replace the previous paragraph in the changelog by :

GCC < 4, on x86_64, does not accept symbol+offset operands for "i"
constraints asm statements. Fallback on a memory read in lieue of
immediate value if this compiler is detected.

As Peter pointed out, talking of "generic immediate value" is rather
confusing.

Mathieu

> Changelog :
> - USE_IMMEDIATE must now be used in lieue of CONFIG_IMMEDIATE in Makefiles and
>   in C code.
> - Every architecture implementing immediate values must declare USE_IMMEDIATE
>   in their Makefile.
> - Tab -> spaces in Makefiles.
> 
> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxx>
> CC: Sam Ravnborg <sam@xxxxxxxxxxxx>
> CC: "H. Peter Anvin" <hpa@xxxxxxxxx>
> CC: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
> CC: Ingo Molnar <mingo@xxxxxxx>
> CC: David Miller <davem@xxxxxxxxxxxxx>
> CC: Paul Mackerras <paulus@xxxxxxxxx>
> ---
>  Makefile                     |    5 +++++
>  arch/powerpc/Makefile        |    2 ++
>  arch/powerpc/kernel/Makefile |    2 +-
>  arch/x86/Makefile            |    5 +++++
>  arch/x86/kernel/Makefile     |    2 +-
>  arch/x86/kernel/traps_32.c   |    4 ++--
>  include/linux/immediate.h    |    2 +-
>  include/linux/module.h       |    4 ++--
>  kernel/Makefile              |    2 +-
>  kernel/module.c              |    8 ++++----
>  10 files changed, 24 insertions(+), 12 deletions(-)
> 
> Index: linux-2.6-sched-devel/arch/x86/Makefile
> ===================================================================
> --- linux-2.6-sched-devel.orig/arch/x86/Makefile	2008-05-21 15:16:06.000000000 -0400
> +++ linux-2.6-sched-devel/arch/x86/Makefile	2008-05-21 15:53:00.000000000 -0400
> @@ -43,6 +43,7 @@
>  
>          # temporary until string.h is fixed
>          KBUILD_CFLAGS += -ffreestanding
> +        export USE_IMMEDIATE := $(CONFIG_IMMEDIATE)
>  else
>          BITS := 64
>          UTS_MACHINE := x86_64
> @@ -78,6 +79,10 @@
>                  "$(CC)" -fstack-protector-all )
>  
>          KBUILD_CFLAGS += $(stackp-y)
> +
> +        # x86_64 gcc 3.x has problems with passing symbol+offset in
> +        # asm "i" constraint.
> +        export USE_IMMEDIATE := $(call cc-ifversion, -ge, 0400, $(CONFIG_IMMEDIATE))
>  endif
>  
>  # Stackpointer is addressed different for 32 bit and 64 bit x86
> Index: linux-2.6-sched-devel/include/linux/immediate.h
> ===================================================================
> --- linux-2.6-sched-devel.orig/include/linux/immediate.h	2008-05-21 15:16:06.000000000 -0400
> +++ linux-2.6-sched-devel/include/linux/immediate.h	2008-05-21 15:16:59.000000000 -0400
> @@ -10,7 +10,7 @@
>   * See the file COPYING for more details.
>   */
>  
> -#ifdef CONFIG_IMMEDIATE
> +#ifdef USE_IMMEDIATE
>  
>  #include <asm/immediate.h>
>  
> Index: linux-2.6-sched-devel/arch/x86/kernel/Makefile
> ===================================================================
> --- linux-2.6-sched-devel.orig/arch/x86/kernel/Makefile	2008-05-21 15:16:51.000000000 -0400
> +++ linux-2.6-sched-devel/arch/x86/kernel/Makefile	2008-05-21 15:16:59.000000000 -0400
> @@ -75,7 +75,7 @@
>  obj-$(CONFIG_KPROBES)		+= kprobes.o
>  obj-$(CONFIG_MODULES)		+= module_$(BITS).o
>  obj-$(CONFIG_ACPI_SRAT) 	+= srat_32.o
> -obj-$(CONFIG_IMMEDIATE)		+= immediate.o
> +obj-$(USE_IMMEDIATE)		+= immediate.o
>  obj-$(CONFIG_EFI) 		+= efi.o efi_$(BITS).o efi_stub_$(BITS).o
>  obj-$(CONFIG_DOUBLEFAULT) 	+= doublefault_32.o
>  obj-$(CONFIG_KGDB)		+= kgdb.o
> Index: linux-2.6-sched-devel/kernel/Makefile
> ===================================================================
> --- linux-2.6-sched-devel.orig/kernel/Makefile	2008-05-21 15:16:52.000000000 -0400
> +++ linux-2.6-sched-devel/kernel/Makefile	2008-05-21 15:16:59.000000000 -0400
> @@ -75,7 +75,7 @@
>  obj-$(CONFIG_SYSCTL) += utsname_sysctl.o
>  obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
>  obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o
> -obj-$(CONFIG_IMMEDIATE) += immediate.o
> +obj-$(USE_IMMEDIATE) += immediate.o
>  obj-$(CONFIG_MARKERS) += marker.o
>  obj-$(CONFIG_LATENCYTOP) += latencytop.o
>  obj-$(CONFIG_FTRACE) += trace/
> Index: linux-2.6-sched-devel/arch/powerpc/Makefile
> ===================================================================
> --- linux-2.6-sched-devel.orig/arch/powerpc/Makefile	2008-05-21 15:16:06.000000000 -0400
> +++ linux-2.6-sched-devel/arch/powerpc/Makefile	2008-05-21 15:16:59.000000000 -0400
> @@ -98,6 +98,8 @@
>  endif
>  endif
>  
> +export USE_IMMEDIATE := $(CONFIG_IMMEDIATE)
> +
>  ifeq ($(CONFIG_TUNE_CELL),y)
>  	KBUILD_CFLAGS += $(call cc-option,-mtune=cell)
>  endif
> Index: linux-2.6-sched-devel/Makefile
> ===================================================================
> --- linux-2.6-sched-devel.orig/Makefile	2008-05-21 15:16:51.000000000 -0400
> +++ linux-2.6-sched-devel/Makefile	2008-05-21 15:16:59.000000000 -0400
> @@ -532,6 +532,11 @@
>  KBUILD_CFLAGS	+= -pg
>  endif
>  
> +# arch Makefile detects if the compiler permits use of immediate values
> +ifdef USE_IMMEDIATE
> +KBUILD_CFLAGS	+= -DUSE_IMMEDIATE
> +endif
> +
>  # We trigger additional mismatches with less inlining
>  ifdef CONFIG_DEBUG_SECTION_MISMATCH
>  KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
> Index: linux-2.6-sched-devel/arch/powerpc/kernel/Makefile
> ===================================================================
> --- linux-2.6-sched-devel.orig/arch/powerpc/kernel/Makefile	2008-05-21 15:16:06.000000000 -0400
> +++ linux-2.6-sched-devel/arch/powerpc/kernel/Makefile	2008-05-21 15:16:59.000000000 -0400
> @@ -45,7 +45,7 @@
>  obj64-$(CONFIG_HIBERNATION)	+= swsusp_asm64.o
>  obj-$(CONFIG_MODULES)		+= module_$(CONFIG_WORD_SIZE).o
>  obj-$(CONFIG_44x)		+= cpu_setup_44x.o
> -obj-$(CONFIG_IMMEDIATE)		+= immediate.o
> +obj-$(USE_IMMEDIATE)		+= immediate.o
>  
>  ifeq ($(CONFIG_PPC_MERGE),y)
>  
> Index: linux-2.6-sched-devel/kernel/module.c
> ===================================================================
> --- linux-2.6-sched-devel.orig/kernel/module.c	2008-05-21 15:16:52.000000000 -0400
> +++ linux-2.6-sched-devel/kernel/module.c	2008-05-21 15:16:59.000000000 -0400
> @@ -2013,7 +2013,7 @@
>  	mod->gpl_future_syms = (void *)sechdrs[gplfutureindex].sh_addr;
>  	if (gplfuturecrcindex)
>  		mod->gpl_future_crcs = (void *)sechdrs[gplfuturecrcindex].sh_addr;
> -#ifdef CONFIG_IMMEDIATE
> +#ifdef USE_IMMEDIATE
>  	mod->immediate = (void *)sechdrs[immediateindex].sh_addr;
>  	mod->num_immediate =
>  		sechdrs[immediateindex].sh_size / sizeof(*mod->immediate);
> @@ -2097,7 +2097,7 @@
>  		marker_update_probe_range(mod->markers,
>  			mod->markers + mod->num_markers);
>  #endif
> -#ifdef CONFIG_IMMEDIATE
> +#ifdef USE_IMMEDIATE
>  		/* Immediate values must be updated after markers */
>  		imv_update_range(mod->immediate,
>  			mod->immediate + mod->num_immediate);
> @@ -2258,7 +2258,7 @@
>  	/* Drop initial reference. */
>  	module_put(mod);
>  	unwind_remove_table(mod->unwind_info, 1);
> -#ifdef CONFIG_IMMEDIATE
> +#ifdef USE_IMMEDIATE
>  	imv_unref(mod->immediate, mod->immediate + mod->num_immediate,
>  		mod->module_init, mod->init_size);
>  #endif
> @@ -2657,7 +2657,7 @@
>  }
>  #endif
>  
> -#ifdef CONFIG_IMMEDIATE
> +#ifdef USE_IMMEDIATE
>  /**
>   * _module_imv_update - update all immediate values in the kernel
>   *
> Index: linux-2.6-sched-devel/include/linux/module.h
> ===================================================================
> --- linux-2.6-sched-devel.orig/include/linux/module.h	2008-05-21 15:16:52.000000000 -0400
> +++ linux-2.6-sched-devel/include/linux/module.h	2008-05-21 15:16:59.000000000 -0400
> @@ -339,7 +339,7 @@
>  	/* The command line arguments (may be mangled).  People like
>  	   keeping pointers to this stuff */
>  	char *args;
> -#ifdef CONFIG_IMMEDIATE
> +#ifdef USE_IMMEDIATE
>  	struct __imv *immediate;
>  	unsigned int num_immediate;
>  	unsigned long *immediate_cond_end;
> @@ -563,7 +563,7 @@
>  
>  #endif /* CONFIG_MODULES */
>  
> -#if defined(CONFIG_MODULES) && defined(CONFIG_IMMEDIATE)
> +#if defined(CONFIG_MODULES) && defined(USE_IMMEDIATE)
>  extern void _module_imv_update(void);
>  extern void module_imv_update(void);
>  extern int is_imv_cond_end_module(unsigned long addr1, unsigned long addr2);
> Index: linux-2.6-sched-devel/arch/x86/kernel/traps_32.c
> ===================================================================
> --- linux-2.6-sched-devel.orig/arch/x86/kernel/traps_32.c	2008-05-21 15:16:06.000000000 -0400
> +++ linux-2.6-sched-devel/arch/x86/kernel/traps_32.c	2008-05-21 15:16:59.000000000 -0400
> @@ -595,7 +595,7 @@
>  }
>  
>  DO_VM86_ERROR_INFO(0, SIGFPE,  "divide error", divide_error, FPE_INTDIV, regs->ip)
> -#if !defined(CONFIG_KPROBES) && !defined(CONFIG_IMMEDIATE)
> +#if !defined(CONFIG_KPROBES) && !defined(USE_IMMEDIATE)
>  DO_VM86_ERROR(3, SIGTRAP, "int3", int3)
>  #endif
>  DO_VM86_ERROR(4, SIGSEGV, "overflow", overflow)
> @@ -860,7 +860,7 @@
>  	acpi_nmi_enable();
>  }
>  
> -#if defined(CONFIG_KPROBES) || defined(CONFIG_IMMEDIATE)
> +#if defined(CONFIG_KPROBES) || defined(USE_IMMEDIATE)
>  void __kprobes do_int3(struct pt_regs *regs, long error_code)
>  {
>  	trace_hardirqs_fixup();
> 
> -- 
> Mathieu Desnoyers
> OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68

-- 
Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68
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