android_kernel_motorola_sm6225/arch/powerpc/kernel/vdso.c
Benjamin Herrenschmidt 7b5acbaac3 [POWERPC] Don't expose clock vDSO functions when CPU has no timebase
We forgot to remove the clock_gettime, clock_getres and get_tbfreq vDSO
calls on CPUs that have no timebase such as 601 or 403 (old CPUs that have
different mechanisms and for which the vDSO code will not work properly).
This fixes it.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-09-19 15:26:34 +10:00

785 lines
19 KiB
C

/*
* Copyright (C) 2004 Benjamin Herrenschmidt, IBM Corp.
* <benh@kernel.crashing.org>
*
* This program 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/module.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/slab.h>
#include <linux/user.h>
#include <linux/elf.h>
#include <linux/security.h>
#include <linux/bootmem.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/processor.h>
#include <asm/mmu.h>
#include <asm/mmu_context.h>
#include <asm/lmb.h>
#include <asm/machdep.h>
#include <asm/cputable.h>
#include <asm/sections.h>
#include <asm/firmware.h>
#include <asm/vdso.h>
#include <asm/vdso_datapage.h>
#include "setup.h"
#undef DEBUG
#ifdef DEBUG
#define DBG(fmt...) printk(fmt)
#else
#define DBG(fmt...)
#endif
/* Max supported size for symbol names */
#define MAX_SYMNAME 64
extern char vdso32_start, vdso32_end;
static void *vdso32_kbase = &vdso32_start;
static unsigned int vdso32_pages;
static struct page **vdso32_pagelist;
unsigned long vdso32_sigtramp;
unsigned long vdso32_rt_sigtramp;
#ifdef CONFIG_PPC64
extern char vdso64_start, vdso64_end;
static void *vdso64_kbase = &vdso64_start;
static unsigned int vdso64_pages;
static struct page **vdso64_pagelist;
unsigned long vdso64_rt_sigtramp;
#endif /* CONFIG_PPC64 */
static int vdso_ready;
/*
* The vdso data page (aka. systemcfg for old ppc64 fans) is here.
* Once the early boot kernel code no longer needs to muck around
* with it, it will become dynamically allocated
*/
static union {
struct vdso_data data;
u8 page[PAGE_SIZE];
} vdso_data_store __attribute__((__section__(".data.page_aligned")));
struct vdso_data *vdso_data = &vdso_data_store.data;
/* Format of the patch table */
struct vdso_patch_def
{
unsigned long ftr_mask, ftr_value;
const char *gen_name;
const char *fix_name;
};
/* Table of functions to patch based on the CPU type/revision
*
* Currently, we only change sync_dicache to do nothing on processors
* with a coherent icache
*/
static struct vdso_patch_def vdso_patches[] = {
{
CPU_FTR_COHERENT_ICACHE, CPU_FTR_COHERENT_ICACHE,
"__kernel_sync_dicache", "__kernel_sync_dicache_p5"
},
{
CPU_FTR_USE_TB, 0,
"__kernel_gettimeofday", NULL
},
{
CPU_FTR_USE_TB, 0,
"__kernel_clock_gettime", NULL
},
{
CPU_FTR_USE_TB, 0,
"__kernel_clock_getres", NULL
},
{
CPU_FTR_USE_TB, 0,
"__kernel_get_tbfreq", NULL
},
};
/*
* Some infos carried around for each of them during parsing at
* boot time.
*/
struct lib32_elfinfo
{
Elf32_Ehdr *hdr; /* ptr to ELF */
Elf32_Sym *dynsym; /* ptr to .dynsym section */
unsigned long dynsymsize; /* size of .dynsym section */
char *dynstr; /* ptr to .dynstr section */
unsigned long text; /* offset of .text section in .so */
};
struct lib64_elfinfo
{
Elf64_Ehdr *hdr;
Elf64_Sym *dynsym;
unsigned long dynsymsize;
char *dynstr;
unsigned long text;
};
#ifdef __DEBUG
static void dump_one_vdso_page(struct page *pg, struct page *upg)
{
printk("kpg: %p (c:%d,f:%08lx)", __va(page_to_pfn(pg) << PAGE_SHIFT),
page_count(pg),
pg->flags);
if (upg/* && pg != upg*/) {
printk(" upg: %p (c:%d,f:%08lx)", __va(page_to_pfn(upg)
<< PAGE_SHIFT),
page_count(upg),
upg->flags);
}
printk("\n");
}
static void dump_vdso_pages(struct vm_area_struct * vma)
{
int i;
if (!vma || test_thread_flag(TIF_32BIT)) {
printk("vDSO32 @ %016lx:\n", (unsigned long)vdso32_kbase);
for (i=0; i<vdso32_pages; i++) {
struct page *pg = virt_to_page(vdso32_kbase +
i*PAGE_SIZE);
struct page *upg = (vma && vma->vm_mm) ?
follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
: NULL;
dump_one_vdso_page(pg, upg);
}
}
if (!vma || !test_thread_flag(TIF_32BIT)) {
printk("vDSO64 @ %016lx:\n", (unsigned long)vdso64_kbase);
for (i=0; i<vdso64_pages; i++) {
struct page *pg = virt_to_page(vdso64_kbase +
i*PAGE_SIZE);
struct page *upg = (vma && vma->vm_mm) ?
follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
: NULL;
dump_one_vdso_page(pg, upg);
}
}
}
#endif /* DEBUG */
/*
* This is called from binfmt_elf, we create the special vma for the
* vDSO and insert it into the mm struct tree
*/
int arch_setup_additional_pages(struct linux_binprm *bprm,
int executable_stack)
{
struct mm_struct *mm = current->mm;
struct page **vdso_pagelist;
unsigned long vdso_pages;
unsigned long vdso_base;
int rc;
if (!vdso_ready)
return 0;
#ifdef CONFIG_PPC64
if (test_thread_flag(TIF_32BIT)) {
vdso_pagelist = vdso32_pagelist;
vdso_pages = vdso32_pages;
vdso_base = VDSO32_MBASE;
} else {
vdso_pagelist = vdso64_pagelist;
vdso_pages = vdso64_pages;
vdso_base = VDSO64_MBASE;
}
#else
vdso_pagelist = vdso32_pagelist;
vdso_pages = vdso32_pages;
vdso_base = VDSO32_MBASE;
#endif
current->mm->context.vdso_base = 0;
/* vDSO has a problem and was disabled, just don't "enable" it for the
* process
*/
if (vdso_pages == 0)
return 0;
/* Add a page to the vdso size for the data page */
vdso_pages ++;
/*
* pick a base address for the vDSO in process space. We try to put it
* at vdso_base which is the "natural" base for it, but we might fail
* and end up putting it elsewhere.
*/
down_write(&mm->mmap_sem);
vdso_base = get_unmapped_area(NULL, vdso_base,
vdso_pages << PAGE_SHIFT, 0, 0);
if (IS_ERR_VALUE(vdso_base)) {
rc = vdso_base;
goto fail_mmapsem;
}
/*
* our vma flags don't have VM_WRITE so by default, the process isn't
* allowed to write those pages.
* gdb can break that with ptrace interface, and thus trigger COW on
* those pages but it's then your responsibility to never do that on
* the "data" page of the vDSO or you'll stop getting kernel updates
* and your nice userland gettimeofday will be totally dead.
* It's fine to use that for setting breakpoints in the vDSO code
* pages though
*
* Make sure the vDSO gets into every core dump.
* Dumping its contents makes post-mortem fully interpretable later
* without matching up the same kernel and hardware config to see
* what PC values meant.
*/
rc = install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT,
VM_READ|VM_EXEC|
VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
VM_ALWAYSDUMP,
vdso_pagelist);
if (rc)
goto fail_mmapsem;
/* Put vDSO base into mm struct */
current->mm->context.vdso_base = vdso_base;
up_write(&mm->mmap_sem);
return 0;
fail_mmapsem:
up_write(&mm->mmap_sem);
return rc;
}
const char *arch_vma_name(struct vm_area_struct *vma)
{
if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso_base)
return "[vdso]";
return NULL;
}
static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
unsigned long *size)
{
Elf32_Shdr *sechdrs;
unsigned int i;
char *secnames;
/* Grab section headers and strings so we can tell who is who */
sechdrs = (void *)ehdr + ehdr->e_shoff;
secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
/* Find the section they want */
for (i = 1; i < ehdr->e_shnum; i++) {
if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
if (size)
*size = sechdrs[i].sh_size;
return (void *)ehdr + sechdrs[i].sh_offset;
}
}
*size = 0;
return NULL;
}
static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
const char *symname)
{
unsigned int i;
char name[MAX_SYMNAME], *c;
for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
if (lib->dynsym[i].st_name == 0)
continue;
strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
MAX_SYMNAME);
c = strchr(name, '@');
if (c)
*c = 0;
if (strcmp(symname, name) == 0)
return &lib->dynsym[i];
}
return NULL;
}
/* Note that we assume the section is .text and the symbol is relative to
* the library base
*/
static unsigned long __init find_function32(struct lib32_elfinfo *lib,
const char *symname)
{
Elf32_Sym *sym = find_symbol32(lib, symname);
if (sym == NULL) {
printk(KERN_WARNING "vDSO32: function %s not found !\n",
symname);
return 0;
}
return sym->st_value - VDSO32_LBASE;
}
static int vdso_do_func_patch32(struct lib32_elfinfo *v32,
struct lib64_elfinfo *v64,
const char *orig, const char *fix)
{
Elf32_Sym *sym32_gen, *sym32_fix;
sym32_gen = find_symbol32(v32, orig);
if (sym32_gen == NULL) {
printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig);
return -1;
}
if (fix == NULL) {
sym32_gen->st_name = 0;
return 0;
}
sym32_fix = find_symbol32(v32, fix);
if (sym32_fix == NULL) {
printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix);
return -1;
}
sym32_gen->st_value = sym32_fix->st_value;
sym32_gen->st_size = sym32_fix->st_size;
sym32_gen->st_info = sym32_fix->st_info;
sym32_gen->st_other = sym32_fix->st_other;
sym32_gen->st_shndx = sym32_fix->st_shndx;
return 0;
}
#ifdef CONFIG_PPC64
static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname,
unsigned long *size)
{
Elf64_Shdr *sechdrs;
unsigned int i;
char *secnames;
/* Grab section headers and strings so we can tell who is who */
sechdrs = (void *)ehdr + ehdr->e_shoff;
secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
/* Find the section they want */
for (i = 1; i < ehdr->e_shnum; i++) {
if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
if (size)
*size = sechdrs[i].sh_size;
return (void *)ehdr + sechdrs[i].sh_offset;
}
}
if (size)
*size = 0;
return NULL;
}
static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib,
const char *symname)
{
unsigned int i;
char name[MAX_SYMNAME], *c;
for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) {
if (lib->dynsym[i].st_name == 0)
continue;
strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
MAX_SYMNAME);
c = strchr(name, '@');
if (c)
*c = 0;
if (strcmp(symname, name) == 0)
return &lib->dynsym[i];
}
return NULL;
}
/* Note that we assume the section is .text and the symbol is relative to
* the library base
*/
static unsigned long __init find_function64(struct lib64_elfinfo *lib,
const char *symname)
{
Elf64_Sym *sym = find_symbol64(lib, symname);
if (sym == NULL) {
printk(KERN_WARNING "vDSO64: function %s not found !\n",
symname);
return 0;
}
#ifdef VDS64_HAS_DESCRIPTORS
return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) -
VDSO64_LBASE;
#else
return sym->st_value - VDSO64_LBASE;
#endif
}
static int vdso_do_func_patch64(struct lib32_elfinfo *v32,
struct lib64_elfinfo *v64,
const char *orig, const char *fix)
{
Elf64_Sym *sym64_gen, *sym64_fix;
sym64_gen = find_symbol64(v64, orig);
if (sym64_gen == NULL) {
printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig);
return -1;
}
if (fix == NULL) {
sym64_gen->st_name = 0;
return 0;
}
sym64_fix = find_symbol64(v64, fix);
if (sym64_fix == NULL) {
printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix);
return -1;
}
sym64_gen->st_value = sym64_fix->st_value;
sym64_gen->st_size = sym64_fix->st_size;
sym64_gen->st_info = sym64_fix->st_info;
sym64_gen->st_other = sym64_fix->st_other;
sym64_gen->st_shndx = sym64_fix->st_shndx;
return 0;
}
#endif /* CONFIG_PPC64 */
static __init int vdso_do_find_sections(struct lib32_elfinfo *v32,
struct lib64_elfinfo *v64)
{
void *sect;
/*
* Locate symbol tables & text section
*/
v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize);
v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL);
if (v32->dynsym == NULL || v32->dynstr == NULL) {
printk(KERN_ERR "vDSO32: required symbol section not found\n");
return -1;
}
sect = find_section32(v32->hdr, ".text", NULL);
if (sect == NULL) {
printk(KERN_ERR "vDSO32: the .text section was not found\n");
return -1;
}
v32->text = sect - vdso32_kbase;
#ifdef CONFIG_PPC64
v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL);
if (v64->dynsym == NULL || v64->dynstr == NULL) {
printk(KERN_ERR "vDSO64: required symbol section not found\n");
return -1;
}
sect = find_section64(v64->hdr, ".text", NULL);
if (sect == NULL) {
printk(KERN_ERR "vDSO64: the .text section was not found\n");
return -1;
}
v64->text = sect - vdso64_kbase;
#endif /* CONFIG_PPC64 */
return 0;
}
static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
struct lib64_elfinfo *v64)
{
/*
* Find signal trampolines
*/
#ifdef CONFIG_PPC64
vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
#endif
vdso32_sigtramp = find_function32(v32, "__kernel_sigtramp32");
vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
}
static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,
struct lib64_elfinfo *v64)
{
Elf32_Sym *sym32;
#ifdef CONFIG_PPC64
Elf64_Sym *sym64;
sym64 = find_symbol64(v64, "__kernel_datapage_offset");
if (sym64 == NULL) {
printk(KERN_ERR "vDSO64: Can't find symbol "
"__kernel_datapage_offset !\n");
return -1;
}
*((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) =
(vdso64_pages << PAGE_SHIFT) -
(sym64->st_value - VDSO64_LBASE);
#endif /* CONFIG_PPC64 */
sym32 = find_symbol32(v32, "__kernel_datapage_offset");
if (sym32 == NULL) {
printk(KERN_ERR "vDSO32: Can't find symbol "
"__kernel_datapage_offset !\n");
return -1;
}
*((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =
(vdso32_pages << PAGE_SHIFT) -
(sym32->st_value - VDSO32_LBASE);
return 0;
}
static __init int vdso_fixup_features(struct lib32_elfinfo *v32,
struct lib64_elfinfo *v64)
{
void *start32;
unsigned long size32;
#ifdef CONFIG_PPC64
void *start64;
unsigned long size64;
start64 = find_section64(v64->hdr, "__ftr_fixup", &size64);
if (start64)
do_feature_fixups(cur_cpu_spec->cpu_features,
start64, start64 + size64);
start64 = find_section64(v64->hdr, "__fw_ftr_fixup", &size64);
if (start64)
do_feature_fixups(powerpc_firmware_features,
start64, start64 + size64);
#endif /* CONFIG_PPC64 */
start32 = find_section32(v32->hdr, "__ftr_fixup", &size32);
if (start32)
do_feature_fixups(cur_cpu_spec->cpu_features,
start32, start32 + size32);
#ifdef CONFIG_PPC64
start32 = find_section32(v32->hdr, "__fw_ftr_fixup", &size32);
if (start32)
do_feature_fixups(powerpc_firmware_features,
start32, start32 + size32);
#endif /* CONFIG_PPC64 */
return 0;
}
static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
struct lib64_elfinfo *v64)
{
int i;
for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
struct vdso_patch_def *patch = &vdso_patches[i];
int match = (cur_cpu_spec->cpu_features & patch->ftr_mask)
== patch->ftr_value;
if (!match)
continue;
DBG("replacing %s with %s...\n", patch->gen_name,
patch->fix_name ? "NONE" : patch->fix_name);
/*
* Patch the 32 bits and 64 bits symbols. Note that we do not
* patch the "." symbol on 64 bits.
* It would be easy to do, but doesn't seem to be necessary,
* patching the OPD symbol is enough.
*/
vdso_do_func_patch32(v32, v64, patch->gen_name,
patch->fix_name);
#ifdef CONFIG_PPC64
vdso_do_func_patch64(v32, v64, patch->gen_name,
patch->fix_name);
#endif /* CONFIG_PPC64 */
}
return 0;
}
static __init int vdso_setup(void)
{
struct lib32_elfinfo v32;
struct lib64_elfinfo v64;
v32.hdr = vdso32_kbase;
#ifdef CONFIG_PPC64
v64.hdr = vdso64_kbase;
#endif
if (vdso_do_find_sections(&v32, &v64))
return -1;
if (vdso_fixup_datapage(&v32, &v64))
return -1;
if (vdso_fixup_features(&v32, &v64))
return -1;
if (vdso_fixup_alt_funcs(&v32, &v64))
return -1;
vdso_setup_trampolines(&v32, &v64);
return 0;
}
/*
* Called from setup_arch to initialize the bitmap of available
* syscalls in the systemcfg page
*/
static void __init vdso_setup_syscall_map(void)
{
unsigned int i;
extern unsigned long *sys_call_table;
extern unsigned long sys_ni_syscall;
for (i = 0; i < __NR_syscalls; i++) {
#ifdef CONFIG_PPC64
if (sys_call_table[i*2] != sys_ni_syscall)
vdso_data->syscall_map_64[i >> 5] |=
0x80000000UL >> (i & 0x1f);
if (sys_call_table[i*2+1] != sys_ni_syscall)
vdso_data->syscall_map_32[i >> 5] |=
0x80000000UL >> (i & 0x1f);
#else /* CONFIG_PPC64 */
if (sys_call_table[i] != sys_ni_syscall)
vdso_data->syscall_map_32[i >> 5] |=
0x80000000UL >> (i & 0x1f);
#endif /* CONFIG_PPC64 */
}
}
static int __init vdso_init(void)
{
int i;
#ifdef CONFIG_PPC64
/*
* Fill up the "systemcfg" stuff for backward compatiblity
*/
strcpy((char *)vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
vdso_data->version.major = SYSTEMCFG_MAJOR;
vdso_data->version.minor = SYSTEMCFG_MINOR;
vdso_data->processor = mfspr(SPRN_PVR);
/*
* Fake the old platform number for pSeries and iSeries and add
* in LPAR bit if necessary
*/
vdso_data->platform = machine_is(iseries) ? 0x200 : 0x100;
if (firmware_has_feature(FW_FEATURE_LPAR))
vdso_data->platform |= 1;
vdso_data->physicalMemorySize = lmb_phys_mem_size();
vdso_data->dcache_size = ppc64_caches.dsize;
vdso_data->dcache_line_size = ppc64_caches.dline_size;
vdso_data->icache_size = ppc64_caches.isize;
vdso_data->icache_line_size = ppc64_caches.iline_size;
/*
* Calculate the size of the 64 bits vDSO
*/
vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages);
#endif /* CONFIG_PPC64 */
/*
* Calculate the size of the 32 bits vDSO
*/
vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT;
DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase, vdso32_pages);
/*
* Setup the syscall map in the vDOS
*/
vdso_setup_syscall_map();
/*
* Initialize the vDSO images in memory, that is do necessary
* fixups of vDSO symbols, locate trampolines, etc...
*/
if (vdso_setup()) {
printk(KERN_ERR "vDSO setup failure, not enabled !\n");
vdso32_pages = 0;
#ifdef CONFIG_PPC64
vdso64_pages = 0;
#endif
return 0;
}
/* Make sure pages are in the correct state */
vdso32_pagelist = kzalloc(sizeof(struct page *) * (vdso32_pages + 2),
GFP_KERNEL);
BUG_ON(vdso32_pagelist == NULL);
for (i = 0; i < vdso32_pages; i++) {
struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
ClearPageReserved(pg);
get_page(pg);
vdso32_pagelist[i] = pg;
}
vdso32_pagelist[i++] = virt_to_page(vdso_data);
vdso32_pagelist[i] = NULL;
#ifdef CONFIG_PPC64
vdso64_pagelist = kzalloc(sizeof(struct page *) * (vdso64_pages + 2),
GFP_KERNEL);
BUG_ON(vdso64_pagelist == NULL);
for (i = 0; i < vdso64_pages; i++) {
struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
ClearPageReserved(pg);
get_page(pg);
vdso64_pagelist[i] = pg;
}
vdso64_pagelist[i++] = virt_to_page(vdso_data);
vdso64_pagelist[i] = NULL;
#endif /* CONFIG_PPC64 */
get_page(virt_to_page(vdso_data));
smp_wmb();
vdso_ready = 1;
return 0;
}
arch_initcall(vdso_init);
int in_gate_area_no_task(unsigned long addr)
{
return 0;
}
int in_gate_area(struct task_struct *task, unsigned long addr)
{
return 0;
}
struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
{
return NULL;
}