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openwrt/target/linux/coldfire/patches/012-Add-vDSO-support-for-Co...

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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);
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