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

From: Mathieu Desnoyers
Date: Wed May 21 2008 - 22:03:33 EST


* 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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