target/linux/coldfire/patches/012-Add-vDSO-support-for-Coldfire-platform.patch

   1 From 1ba9968246337836bf0acdbf7733a628da5c5e42 Mon Sep 17 00:00:00 2001
   2 From: Alison Wang <b18965@freescale.com>
   3 Date: Thu, 4 Aug 2011 09:59:42 +0800
   4 Subject: [PATCH 12/52] Add vDSO support for Coldfire platform
   5
   6 This patch adds vDSO support for Coldfire platform.
   7
   8 Signed-off-by: Alison Wang <b18965@freescale.com>
   9 ---
  10  arch/m68k/coldfire/common/entry.S   |   36 ++++++++++
  11  arch/m68k/coldfire/vdso/Makefile    |   46 +++++++++++++
  12  arch/m68k/coldfire/vdso/vdso-bin.S  |   14 ++++
  13  arch/m68k/coldfire/vdso/vdso-lib.S  |   57 ++++++++++++++++
  14  arch/m68k/coldfire/vdso/vdso-note.S |   27 ++++++++
  15  arch/m68k/coldfire/vdso/vdso.c      |  124 +++++++++++++++++++++++++++++++++++
  16  arch/m68k/coldfire/vdso/vdso.lds.S  |   89 +++++++++++++++++++++++++
  17  arch/m68k/include/asm/auxvec.h      |    9 +++
  18  arch/m68k/mm/init.c                 |    3 +
  19  9 files changed, 405 insertions(+), 0 deletions(-)
  20  create mode 100644 arch/m68k/coldfire/vdso/Makefile
  21  create mode 100644 arch/m68k/coldfire/vdso/vdso-bin.S
  22  create mode 100644 arch/m68k/coldfire/vdso/vdso-lib.S
  23  create mode 100644 arch/m68k/coldfire/vdso/vdso-note.S
  24  create mode 100644 arch/m68k/coldfire/vdso/vdso.c
  25  create mode 100644 arch/m68k/coldfire/vdso/vdso.lds.S
  26
  27 --- a/arch/m68k/coldfire/common/entry.S
  28 +++ b/arch/m68k/coldfire/common/entry.S
  29 @@ -69,6 +69,9 @@ ENTRY(buserr)
  30         movew   #0x2700,%sr             /* lock interrupts */
  31  #endif
  32         SAVE_ALL_INT
  33 +#ifdef CONFIG_VDSO
  34 +       jsr     check_vdso_atomic_cmpxchg_32
  35 +#endif
  36  #ifdef CONFIG_COLDFIRE_FOO
  37         movew   PT_0FF_SR(%sp),%d3              /* get original %sr */
  38         oril    #0x2000,%d3             /* set supervisor mode in it */
  39 @@ -82,6 +85,9 @@ ENTRY(buserr)
  40
  41  ENTRY(trap)
  42         SAVE_ALL_INT
  43 +#ifdef CONFIG_VDSO
  44 +       jsr     check_vdso_atomic_cmpxchg_32
  45 +#endif
  46         GET_CURRENT(%d0)
  47         movel   %sp,%sp@-               /* stack frame pointer argument */
  48         jsr     trap_c
  49 @@ -213,6 +219,9 @@ do_delayed_trace:
  50   */
  51  ENTRY(inthandler)
  52         SAVE_ALL_INT
  53 +#ifdef CONFIG_VDSO
  54 +       jsr     check_vdso_atomic_cmpxchg_32
  55 +#endif
  56         GET_CURRENT(%d0)
  57         movel   %curptr@(TASK_INFO+TINFO_PREEMPT),%d0
  58         addil   #0x10000,%d0
  59 @@ -398,8 +407,35 @@ resume:
  60         movew   %a1@(TASK_THREAD+THREAD_SR),%d0
  61         movew   %d0,%sr
  62
  63 +#ifdef CONFIG_VDSO
  64 +       /* save thread pointer */
  65 +       lea     _vdso_tp,%a0
  66 +       movel   (%a0),%a0
  67 +       movel   %a1@(TASK_INFO+TINFO_TP_VALUE),(%a0)
  68 +#endif
  69         rts
  70
  71 +#ifdef CONFIG_VDSO
  72 +/* if interrupted PC is between 0x5fffe40c to 0x5ffffe412 */
  73 +/* then set PC back to 0x5fffe40c (start addr of __kernel_atomic_cmpxchg_32) */
  74 +/* note: these absolute addresses depend on vdso-lib.S and vdso.lds.S */
  75 +ENTRY(check_vdso_atomic_cmpxchg_32)
  76 +       movel   %sp@(PT_OFF_PC),%d0
  77 +       cmpil   #0x5fffe414,%d0  /* __kernel_atomic_cmpxchg_32: line 4 */
  78 +       ble     label1
  79 +       cmpil   #0x5fffe412,%d0  /* __kernel_atomic_cmpxchg_32: line 3 */
  80 +       beql    label0
  81 +       cmpil   #0x5fffe40e,%d0  /* __kernel_atomic_cmpxchg_32: line 2 */
  82 +       beql    label0
  83 +       jra     label1
  84 +label0:
  85 +       /* __kernel_atomic_cmpxchg_32: line 1 */
  86 +       movel   #0x5fffe40c,%d0
  87 +       movel   %d0,%sp@(PT_OFF_PC)
  88 +label1:
  89 +       rts
  90 +#endif
  91 +
  92  .data
  93  ALIGN
  94  sys_call_table:
  95 --- /dev/null
  96 +++ b/arch/m68k/coldfire/vdso/Makefile
  97 @@ -0,0 +1,46 @@
  98 +#
  99 +# Makefile for arch/m68k/coldfire/vdso with special rules
 100 +# for building the DSO lib
 101 +#
 102 +# Based on arch/sh/kernel/vsyscall/Makefile
 103 +#
 104 +# Kurt Mahan <kmahan@freescale.com>
 105 +#
 106 +
 107 +obj-y := vdso.o vdso-bin.o
 108 +
 109 +$(obj)/vdso-bin.o: $(obj)/vdso.lds $(obj)/vdso-lib.so
 110 +
 111 +#
 112 +# The DSO Lib
 113 +#
 114 +
 115 +# special linker script for building DSO images
 116 +quiet_cmd_vdso = VDSO $@
 117 +      cmd_vdso = $(LD) -nostdlib --eh-frame-hdr $(SYSCFLAGS_$(@F)) \
 118 +                       -T $(obj)/vdso.lds $^ -o $@
 119 +
 120 +vdso-flags = -shared -s -soname=linux-gate.so.1
 121 +
 122 +SYSCFLAGS_vdso-lib.so = $(vdso-flags)
 123 +
 124 +$(obj)/vdso-lib.so: $(obj)/vdso-lib.o $(obj)/vdso-note.o
 125 +       $(call if_changed,vdso)
 126 +
 127 +$(obj)/vdso.lds: $(srctree)/arch/m68k/coldfire/vdso/vdso.lds.S
 128 +       cp $< $@
 129 +
 130 +#
 131 +# Create a special relocatable object that should mirror the
 132 +# symbol table and layout of the linked DSO lib.  With ld -R
 133 +# these symbols can be refered to in the kernel code rather
 134 +# than as hand-coded addresses
 135 +#
 136 +# extra-y += vdso-syms.o
 137 +# $(obj)/built-in.o: $(obj)/vdso-syms.o
 138 +# $(obj)/built-in.o: ld_flags += -R (obj)/vdso-syms.o
 139 +
 140 +# SYSCFLAGS_vdso-syms.o = -r
 141 +# $(obj)/vdso-syms.o: $(src)/vdso.lds \
 142 +#          $(obj)/vdso-lib.o $(obj)/vdso-note.o FORCE
 143 +#      $(call if_changed,vdso)
 144 --- /dev/null
 145 +++ b/arch/m68k/coldfire/vdso/vdso-bin.S
 146 @@ -0,0 +1,14 @@
 147 +/*
 148 + * Setup vdso lib (.so) as binary image.
 149 + */
 150 +
 151 +#include <linux/init.h>
 152 +
 153 +__INITDATA
 154 +
 155 +       .globl vdso_bin_start, vdso_bin_end
 156 +vdso_bin_start:
 157 +       .incbin "arch/m68k/coldfire/vdso/vdso-lib.so"
 158 +vdso_bin_end:
 159 +
 160 +__FINIT
 161 --- /dev/null
 162 +++ b/arch/m68k/coldfire/vdso/vdso-lib.S
 163 @@ -0,0 +1,57 @@
 164 +/*
 165 + * VDSO userspace code
 166 + *
 167 + * Copyright (C) 2008-2011 Freescale Semiconductor, Inc. All Rights Reserved.
 168 + * Kurt Mahan <kmahan@freescale.com>
 169 + *
 170 + * This is free software; you can redistribute it and/or modify
 171 + * it under the terms of the GNU General Public License as published by
 172 + * the Free Software Foundation; either version 2 of the License, or
 173 + * (at your option) any later version.
 174 + */
 175 +
 176 +#include <linux/linkage.h>
 177 +#include <asm/unistd.h>
 178 +
 179 +       .text
 180 +/*
 181 + * Read the thread pointer into A0 (and D0, for compatibility).
 182 + */
 183 +ENTRY(__kernel_read_tp)
 184 +       .cfi_startproc
 185 +       lea     kuser_vdso_tp,%a0
 186 +       movel   (%a0), %d0
 187 +       movel   %d0,%a0
 188 +       rts
 189 +       .cfi_endproc
 190 +       .size __kernel_read_tp,.-__kernel_read_tp
 191 +
 192 +/*
 193 + * Atomic compare exchange.  Can not clobber any registers
 194 + * other than conditional codes.
 195 + */
 196 +ENTRY(__kernel_atomic_cmpxchg_32)
 197 +       .cfi_startproc
 198 +       cmpl    (%a0),%d0
 199 +       bne     label0
 200 +       movel   %d1, (%a0)
 201 +       jmp     label1
 202 +label0:
 203 +       movel   (%a0),%d0
 204 +label1:
 205 +       rts
 206 +       .cfi_endproc
 207 +       .size __kernel_atomic_cmpxchg_32,.-__kernel_atomic_cmpxchg_32
 208 +
 209 +/*
 210 + * Atomic memory barrier.  Can not clobber any registers
 211 + * other than condition codes.
 212 + */
 213 +ENTRY(__kernel_atomic_barrier)
 214 +       .cfi_startproc
 215 +       /* no code needed for uniprocs */
 216 +       rts
 217 +       .cfi_endproc
 218 +       .size __kernel_atomic_barrier,.-__kernel_atomic_barrier
 219 +
 220 +       .previous
 221 --- /dev/null
 222 +++ b/arch/m68k/coldfire/vdso/vdso-note.S
 223 @@ -0,0 +1,27 @@
 224 +/*
 225 + * This supplies .note.* sections to go into the PT_NOTE inside the vDSO text.
 226 + * Here we can supply some information useful to userland.
 227 + *
 228 + * Based on arch/sh/kernel/vsyscall/vsyscall-note.S
 229 + */
 230 +
 231 +#include <linux/uts.h>
 232 +#include <linux/version.h>
 233 +
 234 +#define ASM_ELF_NOTE_BEGIN(name, flags, vendor, type)                        \
 235 +       .section name, flags;                                                 \
 236 +       .balign 4;                                                            \
 237 +       .long 1f - 0f;          /* name length */                             \
 238 +       .long 3f - 2f;          /* data length */                             \
 239 +       .long type;             /* note type */                               \
 240 +0:     .asciz vendor;          /* vendor name */                             \
 241 +1:     .balign 4;                                                            \
 242 +2:
 243 +
 244 +#define ASM_ELF_NOTE_END                                                     \
 245 +3:     .balign 4;              /* pad out section */                         \
 246 +       .previous
 247 +
 248 +       ASM_ELF_NOTE_BEGIN(".note.kernel-version", "a", UTS_SYSNAME, 0)
 249 +       .long LINUX_VERSION_CODE
 250 +       ASM_ELF_NOTE_END
 251 --- /dev/null
 252 +++ b/arch/m68k/coldfire/vdso/vdso.c
 253 @@ -0,0 +1,124 @@
 254 +/*
 255 + * arch/m68k/coldfire/vdso/vdso.c
 256 + *
 257 + * Based on arch/sh/kernel/vsyscall/vsyscall.c
 258 + *
 259 + * Copyright (C) 2008-2011 Freescale Semiconductor, Inc. All Rights Reserved.
 260 + * Kurt Mahan <kmahan@freescale.com>
 261 + *
 262 + * This is free software; you can redistribute it and/or modify
 263 + * it under the terms of the GNU General Public License as published by
 264 + * the Free Software Foundation; either version 2 of the License, or
 265 + * (at your option) any later version.
 266 + */
 267 +
 268 +#include <linux/mm.h>
 269 +#include <linux/slab.h>
 270 +#include <linux/kernel.h>
 271 +#include <linux/init.h>
 272 +#include <linux/gfp.h>
 273 +#include <linux/module.h>
 274 +#include <linux/elf.h>
 275 +#include <linux/sched.h>
 276 +#include <linux/err.h>
 277 +
 278 +/* Mapping vDSO at the default address (what would've been returned
 279 + * if VDSO_MBASE was 0) makes it impossible to extend data segment
 280 + * (through brk()) for static binaries.  The vDSO fits into one page,
 281 + * so map it just before TASK_UNMAPPED_BASE.
 282 + */
 283 +#define VDSO_MBASE (TASK_UNMAPPED_BASE - PAGE_SIZE)
 284 +#define VDSO_VAR_OFFSET        4096
 285 +
 286 +unsigned int vdso_enabled = 1;
 287 +EXPORT_SYMBOL_GPL(vdso_enabled);
 288 +
 289 +static struct page *vdso_pages[1];
 290 +
 291 +/* _vdso_var_start: vdso_page_start + offset_4K */
 292 +/* it's used to save key values from kernel */
 293 +void *_vdso_var_start;
 294 +void *_vdso_tp;
 295 +
 296 +extern const char vdso_bin_start, vdso_bin_end;
 297 +
 298 +int __init vdso_init(void)
 299 +{
 300 +       void *vdso_page = (void *)get_zeroed_page(GFP_ATOMIC);
 301 +       vdso_pages[0] = virt_to_page(vdso_page);
 302 +
 303 +       _vdso_var_start = (void *)(vdso_page + VDSO_VAR_OFFSET);
 304 +       _vdso_tp = _vdso_var_start;
 305 +
 306 +       printk(KERN_INFO "** VDSO_INIT\n");
 307 +
 308 +       /* copy dso bin in */
 309 +       memcpy(vdso_page,
 310 +              &vdso_bin_start, &vdso_bin_end - &vdso_bin_start);
 311 +
 312 +       return 0;
 313 +}
 314 +
 315 +/* setup VMA at program startup for the vdso page */
 316 +int arch_setup_additional_pages(struct linux_binprm *bprm,
 317 +                               int executable_stack)
 318 +{
 319 +       struct mm_struct *mm = current->mm;
 320 +       unsigned long addr;
 321 +       int ret;
 322 +
 323 +       current->mm->context.vdso = 0;
 324 +
 325 +       down_write(&mm->mmap_sem);
 326 +       addr = get_unmapped_area(NULL, VDSO_MBASE, PAGE_SIZE, 0, 0);
 327 +       if (IS_ERR_VALUE(addr)) {
 328 +               ret = addr;
 329 +               goto up_fail;
 330 +       }
 331 +
 332 +       ret = install_special_mapping(mm, addr, PAGE_SIZE,
 333 +                               VM_READ | VM_EXEC |
 334 +                               VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC |
 335 +                               VM_ALWAYSDUMP,
 336 +                               vdso_pages);
 337 +
 338 +       if (unlikely(ret))
 339 +               goto up_fail;
 340 +
 341 +       current->mm->context.vdso = (void *)addr;
 342 +
 343 +up_fail:
 344 +#ifdef DEBUG
 345 +       printk(KERN_DEBUG "arch_setup_additional_pages: addr: %lx; ret: %d\n",
 346 +               addr, ret);
 347 +#endif
 348 +
 349 +       up_write(&mm->mmap_sem);
 350 +       return ret;
 351 +}
 352 +
 353 +/*
 354 + * check vma name
 355 + */
 356 +const char *arch_vma_name(struct vm_area_struct *vma)
 357 +{
 358 +       if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
 359 +               return "[vdso]";
 360 +
 361 +       return NULL;
 362 +}
 363 +
 364 +struct vm_area_struct *get_gate_vma(struct task_struct *task)
 365 +{
 366 +       return NULL;
 367 +}
 368 +
 369 +int in_gate_area(struct task_struct *task, unsigned long address)
 370 +{
 371 +       return 0;
 372 +}
 373 +
 374 +int in_gate_area_no_task(unsigned long address)
 375 +{
 376 +       return 0;
 377 +}
 378 --- /dev/null
 379 +++ b/arch/m68k/coldfire/vdso/vdso.lds.S
 380 @@ -0,0 +1,89 @@
 381 +/*
 382 + * Linker script for vdso DSO.  The vdso page is an ELF shared
 383 + * object prelinked to its virtual address, and with only one read-only
 384 + * segment (that fits in one page).  This script controls its layout.
 385 + *
 386 + * Based on arch/sh/kernel/vsyscall/vsyscall.lds.S
 387 + *
 388 + * Copyright (C) 2008-2011 Freescale Semiconductor, Inc. All Rights Reserved.
 389 + * Kurt Mahan <kmahan@freescale.com>
 390 + *
 391 + * This is free software; you can redistribute it and/or modify
 392 + * it under the terms of the GNU General Public License as published by
 393 + * the Free Software Foundation; either version 2 of the License, or
 394 + * (at your option) any later version.
 395 + */
 396 +
 397 +OUTPUT_FORMAT("elf32-m68k", "elf32-m68k", "elf32-m68k")
 398 +OUTPUT_ARCH(m68k)
 399 +
 400 +/* The ELF entry point can be used to set the AT_SYSINFO value.  */
 401 +ENTRY(__kernel_read_tp);
 402 +ENTRY(__kernel_atomic_cmpxchg_32);
 403 +ENTRY(__kernel_atomic_barrier);
 404 +
 405 +SECTIONS
 406 +{
 407 +       . = 0x5fffe000 + SIZEOF_HEADERS;
 408 +
 409 +       .hash           : { *(.hash) }                  :text
 410 +       .gnu.hash       : { *(.gnu.hash) }
 411 +       .dynsym         : { *(.dynsym) }
 412 +       .dynstr         : { *(.dynstr) }
 413 +       .gnu.version    : { *(.gnu.version) }
 414 +       .gnu.version_d  : { *(.gnu.version_d) }
 415 +       .gnu.version_r  : { *(.gnu.version_r) }
 416 +
 417 +       /*
 418 +        * This linker script is used both with -r and with -shared.
 419 +        * For the layouts to match, we need to skip more than enough
 420 +        * space for the dynamic symbol table et al.  If this amount
 421 +        * is insufficient, ld -shared will barf.  Just increase it here.
 422 +        */
 423 +       . = 0x5fffe000 + 0x400;
 424 +
 425 +       .text           : { *(.text) }                  :text
 426 +       .note           : { *(.note.*) }                :text   :note
 427 +       .eh_frame_hdr   : { *(.eh_frame_hdr ) }         :text   :eh_frame_hdr
 428 +       .eh_frame       : {
 429 +               KEEP (*(.eh_frame))
 430 +               LONG (0)
 431 +       }                                               :text
 432 +       .dynamic        : { *(.dynamic) }               :text   :dynamic
 433 +       .useless        : {
 434 +             *(.got.plt) *(.got)
 435 +             *(.data .data.* .gnu.linkonce.d.*)
 436 +             *(.dynbss)
 437 +             *(.bss .bss.* .gnu.linkonce.b.*)
 438 +       }                                               :text
 439 +
 440 +       . = 0x5fffe000 + 0x1000;
 441 +       kuser_vdso_tp = .;
 442 +}
 443 +
 444 +/*
 445 + * We must supply the ELF program headers explicitly to get just one
 446 + * PT_LOAD segment, and set the flags explicitly to make segments read-only.
 447 + */
 448 +PHDRS
 449 +{
 450 +       text            PT_LOAD FILEHDR PHDRS FLAGS(5); /* PF_R|PF_X */
 451 +       dynamic         PT_DYNAMIC FLAGS(4);            /* PF_R */
 452 +       note            PT_NOTE FLAGS(4);               /* PF_R */
 453 +       eh_frame_hdr    PT_GNU_EH_FRAME;
 454 +}
 455 +
 456 +/*
 457 + * This controls what symbols we export from the DSO.
 458 + */
 459 +VERSION
 460 +{
 461 +       LINUX_2.6 {
 462 +       global:
 463 +               __kernel_read_tp;
 464 +               __kernel_atomic_cmpxchg_32;
 465 +               __kernel_atomic_barrier;
 466 +
 467 +       local: *;
 468 +       };
 469 +}
 470 --- a/arch/m68k/include/asm/auxvec.h
 471 +++ b/arch/m68k/include/asm/auxvec.h
 472 @@ -1,4 +1,13 @@
 473  #ifndef __ASMm68k_AUXVEC_H
 474  #define __ASMm68k_AUXVEC_H
 475 +/*
 476 + * Architecture-neutral AT_ values in 0-17, leave some room
 477 + * for more of them.
 478 + */
 479 +
 480 +#ifdef CONFIG_VDSO
 481 +/* Entry point to the vdso page */
 482 +#define        AT_SYSINFO_EHDR         33
 483 +#endif
 484
 485  #endif
 486 --- a/arch/m68k/mm/init.c
 487 +++ b/arch/m68k/mm/init.c
 488 @@ -39,6 +39,9 @@
 489  #include <asm/sections.h>
 490  #include <asm/tlb.h>
 491
 492 +#ifdef CONFIG_VDSO
 493 +int vdso_init(void);
 494 +#endif
 495
 496  DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
 497