From 1ba9968246337836bf0acdbf7733a628da5c5e42 Mon Sep 17 00:00:00 2001 From: Alison Wang <b18965@freescale.com> Date: Thu, 4 Aug 2011 09:59:42 +0800 Subject: [PATCH 12/52] Add vDSO support for Coldfire platform This patch adds vDSO support for Coldfire platform. Signed-off-by: Alison Wang <b18965@freescale.com> --- arch/m68k/coldfire/common/entry.S | 36 ++++++++++ arch/m68k/coldfire/vdso/Makefile | 46 +++++++++++++ arch/m68k/coldfire/vdso/vdso-bin.S | 14 ++++ arch/m68k/coldfire/vdso/vdso-lib.S | 57 ++++++++++++++++ arch/m68k/coldfire/vdso/vdso-note.S | 27 ++++++++ arch/m68k/coldfire/vdso/vdso.c | 124 +++++++++++++++++++++++++++++++++++ arch/m68k/coldfire/vdso/vdso.lds.S | 89 +++++++++++++++++++++++++ arch/m68k/include/asm/auxvec.h | 9 +++ arch/m68k/mm/init.c | 3 + 9 files changed, 405 insertions(+), 0 deletions(-) create mode 100644 arch/m68k/coldfire/vdso/Makefile create mode 100644 arch/m68k/coldfire/vdso/vdso-bin.S create mode 100644 arch/m68k/coldfire/vdso/vdso-lib.S create mode 100644 arch/m68k/coldfire/vdso/vdso-note.S create mode 100644 arch/m68k/coldfire/vdso/vdso.c create mode 100644 arch/m68k/coldfire/vdso/vdso.lds.S --- a/arch/m68k/coldfire/common/entry.S +++ b/arch/m68k/coldfire/common/entry.S @@ -69,6 +69,9 @@ ENTRY(buserr) movew #0x2700,%sr /* lock interrupts */ #endif SAVE_ALL_INT +#ifdef CONFIG_VDSO + jsr check_vdso_atomic_cmpxchg_32 +#endif #ifdef CONFIG_COLDFIRE_FOO movew PT_0FF_SR(%sp),%d3 /* get original %sr */ oril #0x2000,%d3 /* set supervisor mode in it */ @@ -82,6 +85,9 @@ ENTRY(buserr) ENTRY(trap) SAVE_ALL_INT +#ifdef CONFIG_VDSO + jsr check_vdso_atomic_cmpxchg_32 +#endif GET_CURRENT(%d0) movel %sp,%sp@- /* stack frame pointer argument */ jsr trap_c @@ -213,6 +219,9 @@ do_delayed_trace: */ ENTRY(inthandler) SAVE_ALL_INT +#ifdef CONFIG_VDSO + jsr check_vdso_atomic_cmpxchg_32 +#endif GET_CURRENT(%d0) movel %curptr@(TASK_INFO+TINFO_PREEMPT),%d0 addil #0x10000,%d0 @@ -398,8 +407,35 @@ resume: movew %a1@(TASK_THREAD+THREAD_SR),%d0 movew %d0,%sr +#ifdef CONFIG_VDSO + /* save thread pointer */ + lea _vdso_tp,%a0 + movel (%a0),%a0 + movel %a1@(TASK_INFO+TINFO_TP_VALUE),(%a0) +#endif rts +#ifdef CONFIG_VDSO +/* if interrupted PC is between 0x5fffe40c to 0x5ffffe412 */ +/* then set PC back to 0x5fffe40c (start addr of __kernel_atomic_cmpxchg_32) */ +/* note: these absolute addresses depend on vdso-lib.S and vdso.lds.S */ +ENTRY(check_vdso_atomic_cmpxchg_32) + movel %sp@(PT_OFF_PC),%d0 + cmpil #0x5fffe414,%d0 /* __kernel_atomic_cmpxchg_32: line 4 */ + ble label1 + cmpil #0x5fffe412,%d0 /* __kernel_atomic_cmpxchg_32: line 3 */ + beql label0 + cmpil #0x5fffe40e,%d0 /* __kernel_atomic_cmpxchg_32: line 2 */ + beql label0 + jra label1 +label0: + /* __kernel_atomic_cmpxchg_32: line 1 */ + movel #0x5fffe40c,%d0 + movel %d0,%sp@(PT_OFF_PC) +label1: + rts +#endif + .data ALIGN sys_call_table: --- /dev/null +++ b/arch/m68k/coldfire/vdso/Makefile @@ -0,0 +1,46 @@ +# +# Makefile for arch/m68k/coldfire/vdso with special rules +# for building the DSO lib +# +# Based on arch/sh/kernel/vsyscall/Makefile +# +# Kurt Mahan <kmahan@freescale.com> +# + +obj-y := vdso.o vdso-bin.o + +$(obj)/vdso-bin.o: $(obj)/vdso.lds $(obj)/vdso-lib.so + +# +# The DSO Lib +# + +# special linker script for building DSO images +quiet_cmd_vdso = VDSO $@ + cmd_vdso = $(LD) -nostdlib --eh-frame-hdr $(SYSCFLAGS_$(@F)) \ + -T $(obj)/vdso.lds $^ -o $@ + +vdso-flags = -shared -s -soname=linux-gate.so.1 + +SYSCFLAGS_vdso-lib.so = $(vdso-flags) + +$(obj)/vdso-lib.so: $(obj)/vdso-lib.o $(obj)/vdso-note.o + $(call if_changed,vdso) + +$(obj)/vdso.lds: $(srctree)/arch/m68k/coldfire/vdso/vdso.lds.S + cp $< $@ + +# +# Create a special relocatable object that should mirror the +# symbol table and layout of the linked DSO lib. With ld -R +# these symbols can be refered to in the kernel code rather +# than as hand-coded addresses +# +# extra-y += vdso-syms.o +# $(obj)/built-in.o: $(obj)/vdso-syms.o +# $(obj)/built-in.o: ld_flags += -R (obj)/vdso-syms.o + +# SYSCFLAGS_vdso-syms.o = -r +# $(obj)/vdso-syms.o: $(src)/vdso.lds \ +# $(obj)/vdso-lib.o $(obj)/vdso-note.o FORCE +# $(call if_changed,vdso) --- /dev/null +++ b/arch/m68k/coldfire/vdso/vdso-bin.S @@ -0,0 +1,14 @@ +/* + * Setup vdso lib (.so) as binary image. + */ + +#include <linux/init.h> + +__INITDATA + + .globl vdso_bin_start, vdso_bin_end +vdso_bin_start: + .incbin "arch/m68k/coldfire/vdso/vdso-lib.so" +vdso_bin_end: + +__FINIT --- /dev/null +++ b/arch/m68k/coldfire/vdso/vdso-lib.S @@ -0,0 +1,57 @@ +/* + * VDSO userspace code + * + * Copyright (C) 2008-2011 Freescale Semiconductor, Inc. All Rights Reserved. + * Kurt Mahan <kmahan@freescale.com> + * + * This is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#include <linux/linkage.h> +#include <asm/unistd.h> + + .text +/* + * Read the thread pointer into A0 (and D0, for compatibility). + */ +ENTRY(__kernel_read_tp) + .cfi_startproc + lea kuser_vdso_tp,%a0 + movel (%a0), %d0 + movel %d0,%a0 + rts + .cfi_endproc + .size __kernel_read_tp,.-__kernel_read_tp + +/* + * Atomic compare exchange. Can not clobber any registers + * other than conditional codes. + */ +ENTRY(__kernel_atomic_cmpxchg_32) + .cfi_startproc + cmpl (%a0),%d0 + bne label0 + movel %d1, (%a0) + jmp label1 +label0: + movel (%a0),%d0 +label1: + rts + .cfi_endproc + .size __kernel_atomic_cmpxchg_32,.-__kernel_atomic_cmpxchg_32 + +/* + * Atomic memory barrier. Can not clobber any registers + * other than condition codes. + */ +ENTRY(__kernel_atomic_barrier) + .cfi_startproc + /* no code needed for uniprocs */ + rts + .cfi_endproc + .size __kernel_atomic_barrier,.-__kernel_atomic_barrier + + .previous --- /dev/null +++ b/arch/m68k/coldfire/vdso/vdso-note.S @@ -0,0 +1,27 @@ +/* + * This supplies .note.* sections to go into the PT_NOTE inside the vDSO text. + * Here we can supply some information useful to userland. + * + * Based on arch/sh/kernel/vsyscall/vsyscall-note.S + */ + +#include <linux/uts.h> +#include <linux/version.h> + +#define ASM_ELF_NOTE_BEGIN(name, flags, vendor, type) \ + .section name, flags; \ + .balign 4; \ + .long 1f - 0f; /* name length */ \ + .long 3f - 2f; /* data length */ \ + .long type; /* note type */ \ +0: .asciz vendor; /* vendor name */ \ +1: .balign 4; \ +2: + +#define ASM_ELF_NOTE_END \ +3: .balign 4; /* pad out section */ \ + .previous + + ASM_ELF_NOTE_BEGIN(".note.kernel-version", "a", UTS_SYSNAME, 0) + .long LINUX_VERSION_CODE + ASM_ELF_NOTE_END --- /dev/null +++ b/arch/m68k/coldfire/vdso/vdso.c @@ -0,0 +1,124 @@ +/* + * arch/m68k/coldfire/vdso/vdso.c + * + * Based on arch/sh/kernel/vsyscall/vsyscall.c + * + * Copyright (C) 2008-2011 Freescale Semiconductor, Inc. All Rights Reserved. + * Kurt Mahan <kmahan@freescale.com> + * + * This is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/gfp.h> +#include <linux/module.h> +#include <linux/elf.h> +#include <linux/sched.h> +#include <linux/err.h> + +/* Mapping vDSO at the default address (what would've been returned + * if VDSO_MBASE was 0) makes it impossible to extend data segment + * (through brk()) for static binaries. The vDSO fits into one page, + * so map it just before TASK_UNMAPPED_BASE. + */ +#define VDSO_MBASE (TASK_UNMAPPED_BASE - PAGE_SIZE) +#define VDSO_VAR_OFFSET 4096 + +unsigned int vdso_enabled = 1; +EXPORT_SYMBOL_GPL(vdso_enabled); + +static struct page *vdso_pages[1]; + +/* _vdso_var_start: vdso_page_start + offset_4K */ +/* it's used to save key values from kernel */ +void *_vdso_var_start; +void *_vdso_tp; + +extern const char vdso_bin_start, vdso_bin_end; + +int __init vdso_init(void) +{ + void *vdso_page = (void *)get_zeroed_page(GFP_ATOMIC); + vdso_pages[0] = virt_to_page(vdso_page); + + _vdso_var_start = (void *)(vdso_page + VDSO_VAR_OFFSET); + _vdso_tp = _vdso_var_start; + + printk(KERN_INFO "** VDSO_INIT\n"); + + /* copy dso bin in */ + memcpy(vdso_page, + &vdso_bin_start, &vdso_bin_end - &vdso_bin_start); + + return 0; +} + +/* setup VMA at program startup for the vdso page */ +int arch_setup_additional_pages(struct linux_binprm *bprm, + int executable_stack) +{ + struct mm_struct *mm = current->mm; + unsigned long addr; + int ret; + + current->mm->context.vdso = 0; + + down_write(&mm->mmap_sem); + addr = get_unmapped_area(NULL, VDSO_MBASE, PAGE_SIZE, 0, 0); + if (IS_ERR_VALUE(addr)) { + ret = addr; + goto up_fail; + } + + ret = install_special_mapping(mm, addr, PAGE_SIZE, + VM_READ | VM_EXEC | + VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC | + VM_ALWAYSDUMP, + vdso_pages); + + if (unlikely(ret)) + goto up_fail; + + current->mm->context.vdso = (void *)addr; + +up_fail: +#ifdef DEBUG + printk(KERN_DEBUG "arch_setup_additional_pages: addr: %lx; ret: %d\n", + addr, ret); +#endif + + up_write(&mm->mmap_sem); + return ret; +} + +/* + * check vma name + */ +const char *arch_vma_name(struct vm_area_struct *vma) +{ + if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso) + return "[vdso]"; + + return NULL; +} + +struct vm_area_struct *get_gate_vma(struct task_struct *task) +{ + return NULL; +} + +int in_gate_area(struct task_struct *task, unsigned long address) +{ + return 0; +} + +int in_gate_area_no_task(unsigned long address) +{ + return 0; +} --- /dev/null +++ b/arch/m68k/coldfire/vdso/vdso.lds.S @@ -0,0 +1,89 @@ +/* + * Linker script for vdso DSO. The vdso page is an ELF shared + * object prelinked to its virtual address, and with only one read-only + * segment (that fits in one page). This script controls its layout. + * + * Based on arch/sh/kernel/vsyscall/vsyscall.lds.S + * + * Copyright (C) 2008-2011 Freescale Semiconductor, Inc. All Rights Reserved. + * Kurt Mahan <kmahan@freescale.com> + * + * This is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +OUTPUT_FORMAT("elf32-m68k", "elf32-m68k", "elf32-m68k") +OUTPUT_ARCH(m68k) + +/* The ELF entry point can be used to set the AT_SYSINFO value. */ +ENTRY(__kernel_read_tp); +ENTRY(__kernel_atomic_cmpxchg_32); +ENTRY(__kernel_atomic_barrier); + +SECTIONS +{ + . = 0x5fffe000 + SIZEOF_HEADERS; + + .hash : { *(.hash) } :text + .gnu.hash : { *(.gnu.hash) } + .dynsym : { *(.dynsym) } + .dynstr : { *(.dynstr) } + .gnu.version : { *(.gnu.version) } + .gnu.version_d : { *(.gnu.version_d) } + .gnu.version_r : { *(.gnu.version_r) } + + /* + * This linker script is used both with -r and with -shared. + * For the layouts to match, we need to skip more than enough + * space for the dynamic symbol table et al. If this amount + * is insufficient, ld -shared will barf. Just increase it here. + */ + . = 0x5fffe000 + 0x400; + + .text : { *(.text) } :text + .note : { *(.note.*) } :text :note + .eh_frame_hdr : { *(.eh_frame_hdr ) } :text :eh_frame_hdr + .eh_frame : { + KEEP (*(.eh_frame)) + LONG (0) + } :text + .dynamic : { *(.dynamic) } :text :dynamic + .useless : { + *(.got.plt) *(.got) + *(.data .data.* .gnu.linkonce.d.*) + *(.dynbss) + *(.bss .bss.* .gnu.linkonce.b.*) + } :text + + . = 0x5fffe000 + 0x1000; + kuser_vdso_tp = .; +} + +/* + * We must supply the ELF program headers explicitly to get just one + * PT_LOAD segment, and set the flags explicitly to make segments read-only. + */ +PHDRS +{ + text PT_LOAD FILEHDR PHDRS FLAGS(5); /* PF_R|PF_X */ + dynamic PT_DYNAMIC FLAGS(4); /* PF_R */ + note PT_NOTE FLAGS(4); /* PF_R */ + eh_frame_hdr PT_GNU_EH_FRAME; +} + +/* + * This controls what symbols we export from the DSO. + */ +VERSION +{ + LINUX_2.6 { + global: + __kernel_read_tp; + __kernel_atomic_cmpxchg_32; + __kernel_atomic_barrier; + + local: *; + }; +} --- a/arch/m68k/include/asm/auxvec.h +++ b/arch/m68k/include/asm/auxvec.h @@ -1,4 +1,13 @@ #ifndef __ASMm68k_AUXVEC_H #define __ASMm68k_AUXVEC_H +/* + * Architecture-neutral AT_ values in 0-17, leave some room + * for more of them. + */ + +#ifdef CONFIG_VDSO +/* Entry point to the vdso page */ +#define AT_SYSINFO_EHDR 33 +#endif #endif --- a/arch/m68k/mm/init.c +++ b/arch/m68k/mm/init.c @@ -39,6 +39,9 @@ #include <asm/sections.h> #include <asm/tlb.h> +#ifdef CONFIG_VDSO +int vdso_init(void); +#endif DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);