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1// SPDX-License-Identifier: GPL-2.0-or-later
2
3/*
4 * Copyright (C) 2004 Benjamin Herrenschmidt, IBM Corp.
5 * <benh@kernel.crashing.org>
6 */
7
8#include <linux/errno.h>
9#include <linux/sched.h>
10#include <linux/kernel.h>
11#include <linux/mm.h>
12#include <linux/smp.h>
13#include <linux/stddef.h>
14#include <linux/unistd.h>
15#include <linux/slab.h>
16#include <linux/user.h>
17#include <linux/elf.h>
18#include <linux/security.h>
19#include <linux/memblock.h>
20#include <linux/syscalls.h>
21#include <linux/time_namespace.h>
22#include <vdso/datapage.h>
23
24#include <asm/syscall.h>
25#include <asm/processor.h>
26#include <asm/mmu.h>
27#include <asm/mmu_context.h>
28#include <asm/machdep.h>
29#include <asm/cputable.h>
30#include <asm/sections.h>
31#include <asm/firmware.h>
32#include <asm/vdso.h>
33#include <asm/vdso_datapage.h>
34#include <asm/setup.h>
35
36/* The alignment of the vDSO */
37#define VDSO_ALIGNMENT (1 << 16)
38
39extern char vdso32_start, vdso32_end;
40extern char vdso64_start, vdso64_end;
41
42long sys_ni_syscall(void);
43
44/*
45 * The vdso data page (aka. systemcfg for old ppc64 fans) is here.
46 * Once the early boot kernel code no longer needs to muck around
47 * with it, it will become dynamically allocated
48 */
49static union {
50 struct vdso_arch_data data;
51 u8 page[PAGE_SIZE];
52} vdso_data_store __page_aligned_data;
53struct vdso_arch_data *vdso_data = &vdso_data_store.data;
54
55enum vvar_pages {
56 VVAR_DATA_PAGE_OFFSET,
57 VVAR_TIMENS_PAGE_OFFSET,
58 VVAR_NR_PAGES,
59};
60
61static int vdso_mremap(const struct vm_special_mapping *sm, struct vm_area_struct *new_vma,
62 unsigned long text_size)
63{
64 unsigned long new_size = new_vma->vm_end - new_vma->vm_start;
65
66 if (new_size != text_size)
67 return -EINVAL;
68
69 current->mm->context.vdso = (void __user *)new_vma->vm_start;
70
71 return 0;
72}
73
74static int vdso32_mremap(const struct vm_special_mapping *sm, struct vm_area_struct *new_vma)
75{
76 return vdso_mremap(sm, new_vma, &vdso32_end - &vdso32_start);
77}
78
79static int vdso64_mremap(const struct vm_special_mapping *sm, struct vm_area_struct *new_vma)
80{
81 return vdso_mremap(sm, new_vma, &vdso64_end - &vdso64_start);
82}
83
84static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
85 struct vm_area_struct *vma, struct vm_fault *vmf);
86
87static struct vm_special_mapping vvar_spec __ro_after_init = {
88 .name = "[vvar]",
89 .fault = vvar_fault,
90};
91
92static struct vm_special_mapping vdso32_spec __ro_after_init = {
93 .name = "[vdso]",
94 .mremap = vdso32_mremap,
95};
96
97static struct vm_special_mapping vdso64_spec __ro_after_init = {
98 .name = "[vdso]",
99 .mremap = vdso64_mremap,
100};
101
102#ifdef CONFIG_TIME_NS
103struct vdso_data *arch_get_vdso_data(void *vvar_page)
104{
105 return ((struct vdso_arch_data *)vvar_page)->data;
106}
107
108/*
109 * The vvar mapping contains data for a specific time namespace, so when a task
110 * changes namespace we must unmap its vvar data for the old namespace.
111 * Subsequent faults will map in data for the new namespace.
112 *
113 * For more details see timens_setup_vdso_data().
114 */
115int vdso_join_timens(struct task_struct *task, struct time_namespace *ns)
116{
117 struct mm_struct *mm = task->mm;
118 VMA_ITERATOR(vmi, mm, 0);
119 struct vm_area_struct *vma;
120
121 mmap_read_lock(mm);
122 for_each_vma(vmi, vma) {
123 unsigned long size = vma->vm_end - vma->vm_start;
124
125 if (vma_is_special_mapping(vma, &vvar_spec))
126 zap_page_range(vma, vma->vm_start, size);
127 }
128 mmap_read_unlock(mm);
129
130 return 0;
131}
132#endif
133
134static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
135 struct vm_area_struct *vma, struct vm_fault *vmf)
136{
137 struct page *timens_page = find_timens_vvar_page(vma);
138 unsigned long pfn;
139
140 switch (vmf->pgoff) {
141 case VVAR_DATA_PAGE_OFFSET:
142 if (timens_page)
143 pfn = page_to_pfn(timens_page);
144 else
145 pfn = virt_to_pfn(vdso_data);
146 break;
147#ifdef CONFIG_TIME_NS
148 case VVAR_TIMENS_PAGE_OFFSET:
149 /*
150 * If a task belongs to a time namespace then a namespace
151 * specific VVAR is mapped with the VVAR_DATA_PAGE_OFFSET and
152 * the real VVAR page is mapped with the VVAR_TIMENS_PAGE_OFFSET
153 * offset.
154 * See also the comment near timens_setup_vdso_data().
155 */
156 if (!timens_page)
157 return VM_FAULT_SIGBUS;
158 pfn = virt_to_pfn(vdso_data);
159 break;
160#endif /* CONFIG_TIME_NS */
161 default:
162 return VM_FAULT_SIGBUS;
163 }
164
165 return vmf_insert_pfn(vma, vmf->address, pfn);
166}
167
168/*
169 * This is called from binfmt_elf, we create the special vma for the
170 * vDSO and insert it into the mm struct tree
171 */
172static int __arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
173{
174 unsigned long vdso_size, vdso_base, mappings_size;
175 struct vm_special_mapping *vdso_spec;
176 unsigned long vvar_size = VVAR_NR_PAGES * PAGE_SIZE;
177 struct mm_struct *mm = current->mm;
178 struct vm_area_struct *vma;
179
180 if (is_32bit_task()) {
181 vdso_spec = &vdso32_spec;
182 vdso_size = &vdso32_end - &vdso32_start;
183 } else {
184 vdso_spec = &vdso64_spec;
185 vdso_size = &vdso64_end - &vdso64_start;
186 }
187
188 mappings_size = vdso_size + vvar_size;
189 mappings_size += (VDSO_ALIGNMENT - 1) & PAGE_MASK;
190
191 /*
192 * Pick a base address for the vDSO in process space.
193 * Add enough to the size so that the result can be aligned.
194 */
195 vdso_base = get_unmapped_area(NULL, 0, mappings_size, 0, 0);
196 if (IS_ERR_VALUE(vdso_base))
197 return vdso_base;
198
199 /* Add required alignment. */
200 vdso_base = ALIGN(vdso_base, VDSO_ALIGNMENT);
201
202 /*
203 * Put vDSO base into mm struct. We need to do this before calling
204 * install_special_mapping or the perf counter mmap tracking code
205 * will fail to recognise it as a vDSO.
206 */
207 mm->context.vdso = (void __user *)vdso_base + vvar_size;
208
209 vma = _install_special_mapping(mm, vdso_base, vvar_size,
210 VM_READ | VM_MAYREAD | VM_IO |
211 VM_DONTDUMP | VM_PFNMAP, &vvar_spec);
212 if (IS_ERR(vma))
213 return PTR_ERR(vma);
214
215 /*
216 * our vma flags don't have VM_WRITE so by default, the process isn't
217 * allowed to write those pages.
218 * gdb can break that with ptrace interface, and thus trigger COW on
219 * those pages but it's then your responsibility to never do that on
220 * the "data" page of the vDSO or you'll stop getting kernel updates
221 * and your nice userland gettimeofday will be totally dead.
222 * It's fine to use that for setting breakpoints in the vDSO code
223 * pages though.
224 */
225 vma = _install_special_mapping(mm, vdso_base + vvar_size, vdso_size,
226 VM_READ | VM_EXEC | VM_MAYREAD |
227 VM_MAYWRITE | VM_MAYEXEC, vdso_spec);
228 if (IS_ERR(vma))
229 do_munmap(mm, vdso_base, vvar_size, NULL);
230
231 return PTR_ERR_OR_ZERO(vma);
232}
233
234int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
235{
236 struct mm_struct *mm = current->mm;
237 int rc;
238
239 mm->context.vdso = NULL;
240
241 if (mmap_write_lock_killable(mm))
242 return -EINTR;
243
244 rc = __arch_setup_additional_pages(bprm, uses_interp);
245 if (rc)
246 mm->context.vdso = NULL;
247
248 mmap_write_unlock(mm);
249 return rc;
250}
251
252#define VDSO_DO_FIXUPS(type, value, bits, sec) do { \
253 void *__start = (void *)VDSO##bits##_SYMBOL(&vdso##bits##_start, sec##_start); \
254 void *__end = (void *)VDSO##bits##_SYMBOL(&vdso##bits##_start, sec##_end); \
255 \
256 do_##type##_fixups((value), __start, __end); \
257} while (0)
258
259static void __init vdso_fixup_features(void)
260{
261#ifdef CONFIG_PPC64
262 VDSO_DO_FIXUPS(feature, cur_cpu_spec->cpu_features, 64, ftr_fixup);
263 VDSO_DO_FIXUPS(feature, cur_cpu_spec->mmu_features, 64, mmu_ftr_fixup);
264 VDSO_DO_FIXUPS(feature, powerpc_firmware_features, 64, fw_ftr_fixup);
265 VDSO_DO_FIXUPS(lwsync, cur_cpu_spec->cpu_features, 64, lwsync_fixup);
266#endif /* CONFIG_PPC64 */
267
268#ifdef CONFIG_VDSO32
269 VDSO_DO_FIXUPS(feature, cur_cpu_spec->cpu_features, 32, ftr_fixup);
270 VDSO_DO_FIXUPS(feature, cur_cpu_spec->mmu_features, 32, mmu_ftr_fixup);
271#ifdef CONFIG_PPC64
272 VDSO_DO_FIXUPS(feature, powerpc_firmware_features, 32, fw_ftr_fixup);
273#endif /* CONFIG_PPC64 */
274 VDSO_DO_FIXUPS(lwsync, cur_cpu_spec->cpu_features, 32, lwsync_fixup);
275#endif
276}
277
278/*
279 * Called from setup_arch to initialize the bitmap of available
280 * syscalls in the systemcfg page
281 */
282static void __init vdso_setup_syscall_map(void)
283{
284 unsigned int i;
285
286 for (i = 0; i < NR_syscalls; i++) {
287 if (sys_call_table[i] != (void *)&sys_ni_syscall)
288 vdso_data->syscall_map[i >> 5] |= 0x80000000UL >> (i & 0x1f);
289 if (IS_ENABLED(CONFIG_COMPAT) &&
290 compat_sys_call_table[i] != (void *)&sys_ni_syscall)
291 vdso_data->compat_syscall_map[i >> 5] |= 0x80000000UL >> (i & 0x1f);
292 }
293}
294
295#ifdef CONFIG_PPC64
296int vdso_getcpu_init(void)
297{
298 unsigned long cpu, node, val;
299
300 /*
301 * SPRG_VDSO contains the CPU in the bottom 16 bits and the NUMA node
302 * in the next 16 bits. The VDSO uses this to implement getcpu().
303 */
304 cpu = get_cpu();
305 WARN_ON_ONCE(cpu > 0xffff);
306
307 node = cpu_to_node(cpu);
308 WARN_ON_ONCE(node > 0xffff);
309
310 val = (cpu & 0xffff) | ((node & 0xffff) << 16);
311 mtspr(SPRN_SPRG_VDSO_WRITE, val);
312 get_paca()->sprg_vdso = val;
313
314 put_cpu();
315
316 return 0;
317}
318/* We need to call this before SMP init */
319early_initcall(vdso_getcpu_init);
320#endif
321
322static struct page ** __init vdso_setup_pages(void *start, void *end)
323{
324 int i;
325 struct page **pagelist;
326 int pages = (end - start) >> PAGE_SHIFT;
327
328 pagelist = kcalloc(pages + 1, sizeof(struct page *), GFP_KERNEL);
329 if (!pagelist)
330 panic("%s: Cannot allocate page list for VDSO", __func__);
331
332 for (i = 0; i < pages; i++)
333 pagelist[i] = virt_to_page(start + i * PAGE_SIZE);
334
335 return pagelist;
336}
337
338static int __init vdso_init(void)
339{
340#ifdef CONFIG_PPC64
341 /*
342 * Fill up the "systemcfg" stuff for backward compatibility
343 */
344 strcpy((char *)vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
345 vdso_data->version.major = SYSTEMCFG_MAJOR;
346 vdso_data->version.minor = SYSTEMCFG_MINOR;
347 vdso_data->processor = mfspr(SPRN_PVR);
348 /*
349 * Fake the old platform number for pSeries and add
350 * in LPAR bit if necessary
351 */
352 vdso_data->platform = 0x100;
353 if (firmware_has_feature(FW_FEATURE_LPAR))
354 vdso_data->platform |= 1;
355 vdso_data->physicalMemorySize = memblock_phys_mem_size();
356 vdso_data->dcache_size = ppc64_caches.l1d.size;
357 vdso_data->dcache_line_size = ppc64_caches.l1d.line_size;
358 vdso_data->icache_size = ppc64_caches.l1i.size;
359 vdso_data->icache_line_size = ppc64_caches.l1i.line_size;
360 vdso_data->dcache_block_size = ppc64_caches.l1d.block_size;
361 vdso_data->icache_block_size = ppc64_caches.l1i.block_size;
362 vdso_data->dcache_log_block_size = ppc64_caches.l1d.log_block_size;
363 vdso_data->icache_log_block_size = ppc64_caches.l1i.log_block_size;
364#endif /* CONFIG_PPC64 */
365
366 vdso_setup_syscall_map();
367
368 vdso_fixup_features();
369
370 if (IS_ENABLED(CONFIG_VDSO32))
371 vdso32_spec.pages = vdso_setup_pages(&vdso32_start, &vdso32_end);
372
373 if (IS_ENABLED(CONFIG_PPC64))
374 vdso64_spec.pages = vdso_setup_pages(&vdso64_start, &vdso64_end);
375
376 smp_wmb();
377
378 return 0;
379}
380arch_initcall(vdso_init);
1
2/*
3 * Copyright (C) 2004 Benjamin Herrenschmidt, IBM Corp.
4 * <benh@kernel.crashing.org>
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12#include <linux/module.h>
13#include <linux/errno.h>
14#include <linux/sched.h>
15#include <linux/kernel.h>
16#include <linux/mm.h>
17#include <linux/smp.h>
18#include <linux/stddef.h>
19#include <linux/unistd.h>
20#include <linux/slab.h>
21#include <linux/user.h>
22#include <linux/elf.h>
23#include <linux/security.h>
24#include <linux/bootmem.h>
25#include <linux/memblock.h>
26
27#include <asm/pgtable.h>
28#include <asm/system.h>
29#include <asm/processor.h>
30#include <asm/mmu.h>
31#include <asm/mmu_context.h>
32#include <asm/prom.h>
33#include <asm/machdep.h>
34#include <asm/cputable.h>
35#include <asm/sections.h>
36#include <asm/firmware.h>
37#include <asm/vdso.h>
38#include <asm/vdso_datapage.h>
39
40#include "setup.h"
41
42#undef DEBUG
43
44#ifdef DEBUG
45#define DBG(fmt...) printk(fmt)
46#else
47#define DBG(fmt...)
48#endif
49
50/* Max supported size for symbol names */
51#define MAX_SYMNAME 64
52
53/* The alignment of the vDSO */
54#define VDSO_ALIGNMENT (1 << 16)
55
56extern char vdso32_start, vdso32_end;
57static void *vdso32_kbase = &vdso32_start;
58static unsigned int vdso32_pages;
59static struct page **vdso32_pagelist;
60unsigned long vdso32_sigtramp;
61unsigned long vdso32_rt_sigtramp;
62
63#ifdef CONFIG_PPC64
64extern char vdso64_start, vdso64_end;
65static void *vdso64_kbase = &vdso64_start;
66static unsigned int vdso64_pages;
67static struct page **vdso64_pagelist;
68unsigned long vdso64_rt_sigtramp;
69#endif /* CONFIG_PPC64 */
70
71static int vdso_ready;
72
73/*
74 * The vdso data page (aka. systemcfg for old ppc64 fans) is here.
75 * Once the early boot kernel code no longer needs to muck around
76 * with it, it will become dynamically allocated
77 */
78static union {
79 struct vdso_data data;
80 u8 page[PAGE_SIZE];
81} vdso_data_store __page_aligned_data;
82struct vdso_data *vdso_data = &vdso_data_store.data;
83
84/* Format of the patch table */
85struct vdso_patch_def
86{
87 unsigned long ftr_mask, ftr_value;
88 const char *gen_name;
89 const char *fix_name;
90};
91
92/* Table of functions to patch based on the CPU type/revision
93 *
94 * Currently, we only change sync_dicache to do nothing on processors
95 * with a coherent icache
96 */
97static struct vdso_patch_def vdso_patches[] = {
98 {
99 CPU_FTR_COHERENT_ICACHE, CPU_FTR_COHERENT_ICACHE,
100 "__kernel_sync_dicache", "__kernel_sync_dicache_p5"
101 },
102 {
103 CPU_FTR_USE_TB, 0,
104 "__kernel_gettimeofday", NULL
105 },
106 {
107 CPU_FTR_USE_TB, 0,
108 "__kernel_clock_gettime", NULL
109 },
110 {
111 CPU_FTR_USE_TB, 0,
112 "__kernel_clock_getres", NULL
113 },
114 {
115 CPU_FTR_USE_TB, 0,
116 "__kernel_get_tbfreq", NULL
117 },
118};
119
120/*
121 * Some infos carried around for each of them during parsing at
122 * boot time.
123 */
124struct lib32_elfinfo
125{
126 Elf32_Ehdr *hdr; /* ptr to ELF */
127 Elf32_Sym *dynsym; /* ptr to .dynsym section */
128 unsigned long dynsymsize; /* size of .dynsym section */
129 char *dynstr; /* ptr to .dynstr section */
130 unsigned long text; /* offset of .text section in .so */
131};
132
133struct lib64_elfinfo
134{
135 Elf64_Ehdr *hdr;
136 Elf64_Sym *dynsym;
137 unsigned long dynsymsize;
138 char *dynstr;
139 unsigned long text;
140};
141
142
143#ifdef __DEBUG
144static void dump_one_vdso_page(struct page *pg, struct page *upg)
145{
146 printk("kpg: %p (c:%d,f:%08lx)", __va(page_to_pfn(pg) << PAGE_SHIFT),
147 page_count(pg),
148 pg->flags);
149 if (upg && !IS_ERR(upg) /* && pg != upg*/) {
150 printk(" upg: %p (c:%d,f:%08lx)", __va(page_to_pfn(upg)
151 << PAGE_SHIFT),
152 page_count(upg),
153 upg->flags);
154 }
155 printk("\n");
156}
157
158static void dump_vdso_pages(struct vm_area_struct * vma)
159{
160 int i;
161
162 if (!vma || is_32bit_task()) {
163 printk("vDSO32 @ %016lx:\n", (unsigned long)vdso32_kbase);
164 for (i=0; i<vdso32_pages; i++) {
165 struct page *pg = virt_to_page(vdso32_kbase +
166 i*PAGE_SIZE);
167 struct page *upg = (vma && vma->vm_mm) ?
168 follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
169 : NULL;
170 dump_one_vdso_page(pg, upg);
171 }
172 }
173 if (!vma || !is_32bit_task()) {
174 printk("vDSO64 @ %016lx:\n", (unsigned long)vdso64_kbase);
175 for (i=0; i<vdso64_pages; i++) {
176 struct page *pg = virt_to_page(vdso64_kbase +
177 i*PAGE_SIZE);
178 struct page *upg = (vma && vma->vm_mm) ?
179 follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
180 : NULL;
181 dump_one_vdso_page(pg, upg);
182 }
183 }
184}
185#endif /* DEBUG */
186
187/*
188 * This is called from binfmt_elf, we create the special vma for the
189 * vDSO and insert it into the mm struct tree
190 */
191int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
192{
193 struct mm_struct *mm = current->mm;
194 struct page **vdso_pagelist;
195 unsigned long vdso_pages;
196 unsigned long vdso_base;
197 int rc;
198
199 if (!vdso_ready)
200 return 0;
201
202#ifdef CONFIG_PPC64
203 if (is_32bit_task()) {
204 vdso_pagelist = vdso32_pagelist;
205 vdso_pages = vdso32_pages;
206 vdso_base = VDSO32_MBASE;
207 } else {
208 vdso_pagelist = vdso64_pagelist;
209 vdso_pages = vdso64_pages;
210 /*
211 * On 64bit we don't have a preferred map address. This
212 * allows get_unmapped_area to find an area near other mmaps
213 * and most likely share a SLB entry.
214 */
215 vdso_base = 0;
216 }
217#else
218 vdso_pagelist = vdso32_pagelist;
219 vdso_pages = vdso32_pages;
220 vdso_base = VDSO32_MBASE;
221#endif
222
223 current->mm->context.vdso_base = 0;
224
225 /* vDSO has a problem and was disabled, just don't "enable" it for the
226 * process
227 */
228 if (vdso_pages == 0)
229 return 0;
230 /* Add a page to the vdso size for the data page */
231 vdso_pages ++;
232
233 /*
234 * pick a base address for the vDSO in process space. We try to put it
235 * at vdso_base which is the "natural" base for it, but we might fail
236 * and end up putting it elsewhere.
237 * Add enough to the size so that the result can be aligned.
238 */
239 down_write(&mm->mmap_sem);
240 vdso_base = get_unmapped_area(NULL, vdso_base,
241 (vdso_pages << PAGE_SHIFT) +
242 ((VDSO_ALIGNMENT - 1) & PAGE_MASK),
243 0, 0);
244 if (IS_ERR_VALUE(vdso_base)) {
245 rc = vdso_base;
246 goto fail_mmapsem;
247 }
248
249 /* Add required alignment. */
250 vdso_base = ALIGN(vdso_base, VDSO_ALIGNMENT);
251
252 /*
253 * Put vDSO base into mm struct. We need to do this before calling
254 * install_special_mapping or the perf counter mmap tracking code
255 * will fail to recognise it as a vDSO (since arch_vma_name fails).
256 */
257 current->mm->context.vdso_base = vdso_base;
258
259 /*
260 * our vma flags don't have VM_WRITE so by default, the process isn't
261 * allowed to write those pages.
262 * gdb can break that with ptrace interface, and thus trigger COW on
263 * those pages but it's then your responsibility to never do that on
264 * the "data" page of the vDSO or you'll stop getting kernel updates
265 * and your nice userland gettimeofday will be totally dead.
266 * It's fine to use that for setting breakpoints in the vDSO code
267 * pages though
268 *
269 * Make sure the vDSO gets into every core dump.
270 * Dumping its contents makes post-mortem fully interpretable later
271 * without matching up the same kernel and hardware config to see
272 * what PC values meant.
273 */
274 rc = install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT,
275 VM_READ|VM_EXEC|
276 VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
277 VM_ALWAYSDUMP,
278 vdso_pagelist);
279 if (rc) {
280 current->mm->context.vdso_base = 0;
281 goto fail_mmapsem;
282 }
283
284 up_write(&mm->mmap_sem);
285 return 0;
286
287 fail_mmapsem:
288 up_write(&mm->mmap_sem);
289 return rc;
290}
291
292const char *arch_vma_name(struct vm_area_struct *vma)
293{
294 if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso_base)
295 return "[vdso]";
296 return NULL;
297}
298
299
300
301static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
302 unsigned long *size)
303{
304 Elf32_Shdr *sechdrs;
305 unsigned int i;
306 char *secnames;
307
308 /* Grab section headers and strings so we can tell who is who */
309 sechdrs = (void *)ehdr + ehdr->e_shoff;
310 secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
311
312 /* Find the section they want */
313 for (i = 1; i < ehdr->e_shnum; i++) {
314 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
315 if (size)
316 *size = sechdrs[i].sh_size;
317 return (void *)ehdr + sechdrs[i].sh_offset;
318 }
319 }
320 *size = 0;
321 return NULL;
322}
323
324static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
325 const char *symname)
326{
327 unsigned int i;
328 char name[MAX_SYMNAME], *c;
329
330 for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
331 if (lib->dynsym[i].st_name == 0)
332 continue;
333 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
334 MAX_SYMNAME);
335 c = strchr(name, '@');
336 if (c)
337 *c = 0;
338 if (strcmp(symname, name) == 0)
339 return &lib->dynsym[i];
340 }
341 return NULL;
342}
343
344/* Note that we assume the section is .text and the symbol is relative to
345 * the library base
346 */
347static unsigned long __init find_function32(struct lib32_elfinfo *lib,
348 const char *symname)
349{
350 Elf32_Sym *sym = find_symbol32(lib, symname);
351
352 if (sym == NULL) {
353 printk(KERN_WARNING "vDSO32: function %s not found !\n",
354 symname);
355 return 0;
356 }
357 return sym->st_value - VDSO32_LBASE;
358}
359
360static int __init vdso_do_func_patch32(struct lib32_elfinfo *v32,
361 struct lib64_elfinfo *v64,
362 const char *orig, const char *fix)
363{
364 Elf32_Sym *sym32_gen, *sym32_fix;
365
366 sym32_gen = find_symbol32(v32, orig);
367 if (sym32_gen == NULL) {
368 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig);
369 return -1;
370 }
371 if (fix == NULL) {
372 sym32_gen->st_name = 0;
373 return 0;
374 }
375 sym32_fix = find_symbol32(v32, fix);
376 if (sym32_fix == NULL) {
377 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix);
378 return -1;
379 }
380 sym32_gen->st_value = sym32_fix->st_value;
381 sym32_gen->st_size = sym32_fix->st_size;
382 sym32_gen->st_info = sym32_fix->st_info;
383 sym32_gen->st_other = sym32_fix->st_other;
384 sym32_gen->st_shndx = sym32_fix->st_shndx;
385
386 return 0;
387}
388
389
390#ifdef CONFIG_PPC64
391
392static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname,
393 unsigned long *size)
394{
395 Elf64_Shdr *sechdrs;
396 unsigned int i;
397 char *secnames;
398
399 /* Grab section headers and strings so we can tell who is who */
400 sechdrs = (void *)ehdr + ehdr->e_shoff;
401 secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
402
403 /* Find the section they want */
404 for (i = 1; i < ehdr->e_shnum; i++) {
405 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
406 if (size)
407 *size = sechdrs[i].sh_size;
408 return (void *)ehdr + sechdrs[i].sh_offset;
409 }
410 }
411 if (size)
412 *size = 0;
413 return NULL;
414}
415
416static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib,
417 const char *symname)
418{
419 unsigned int i;
420 char name[MAX_SYMNAME], *c;
421
422 for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) {
423 if (lib->dynsym[i].st_name == 0)
424 continue;
425 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
426 MAX_SYMNAME);
427 c = strchr(name, '@');
428 if (c)
429 *c = 0;
430 if (strcmp(symname, name) == 0)
431 return &lib->dynsym[i];
432 }
433 return NULL;
434}
435
436/* Note that we assume the section is .text and the symbol is relative to
437 * the library base
438 */
439static unsigned long __init find_function64(struct lib64_elfinfo *lib,
440 const char *symname)
441{
442 Elf64_Sym *sym = find_symbol64(lib, symname);
443
444 if (sym == NULL) {
445 printk(KERN_WARNING "vDSO64: function %s not found !\n",
446 symname);
447 return 0;
448 }
449#ifdef VDS64_HAS_DESCRIPTORS
450 return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) -
451 VDSO64_LBASE;
452#else
453 return sym->st_value - VDSO64_LBASE;
454#endif
455}
456
457static int __init vdso_do_func_patch64(struct lib32_elfinfo *v32,
458 struct lib64_elfinfo *v64,
459 const char *orig, const char *fix)
460{
461 Elf64_Sym *sym64_gen, *sym64_fix;
462
463 sym64_gen = find_symbol64(v64, orig);
464 if (sym64_gen == NULL) {
465 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig);
466 return -1;
467 }
468 if (fix == NULL) {
469 sym64_gen->st_name = 0;
470 return 0;
471 }
472 sym64_fix = find_symbol64(v64, fix);
473 if (sym64_fix == NULL) {
474 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix);
475 return -1;
476 }
477 sym64_gen->st_value = sym64_fix->st_value;
478 sym64_gen->st_size = sym64_fix->st_size;
479 sym64_gen->st_info = sym64_fix->st_info;
480 sym64_gen->st_other = sym64_fix->st_other;
481 sym64_gen->st_shndx = sym64_fix->st_shndx;
482
483 return 0;
484}
485
486#endif /* CONFIG_PPC64 */
487
488
489static __init int vdso_do_find_sections(struct lib32_elfinfo *v32,
490 struct lib64_elfinfo *v64)
491{
492 void *sect;
493
494 /*
495 * Locate symbol tables & text section
496 */
497
498 v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize);
499 v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL);
500 if (v32->dynsym == NULL || v32->dynstr == NULL) {
501 printk(KERN_ERR "vDSO32: required symbol section not found\n");
502 return -1;
503 }
504 sect = find_section32(v32->hdr, ".text", NULL);
505 if (sect == NULL) {
506 printk(KERN_ERR "vDSO32: the .text section was not found\n");
507 return -1;
508 }
509 v32->text = sect - vdso32_kbase;
510
511#ifdef CONFIG_PPC64
512 v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
513 v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL);
514 if (v64->dynsym == NULL || v64->dynstr == NULL) {
515 printk(KERN_ERR "vDSO64: required symbol section not found\n");
516 return -1;
517 }
518 sect = find_section64(v64->hdr, ".text", NULL);
519 if (sect == NULL) {
520 printk(KERN_ERR "vDSO64: the .text section was not found\n");
521 return -1;
522 }
523 v64->text = sect - vdso64_kbase;
524#endif /* CONFIG_PPC64 */
525
526 return 0;
527}
528
529static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
530 struct lib64_elfinfo *v64)
531{
532 /*
533 * Find signal trampolines
534 */
535
536#ifdef CONFIG_PPC64
537 vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
538#endif
539 vdso32_sigtramp = find_function32(v32, "__kernel_sigtramp32");
540 vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
541}
542
543static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,
544 struct lib64_elfinfo *v64)
545{
546 Elf32_Sym *sym32;
547#ifdef CONFIG_PPC64
548 Elf64_Sym *sym64;
549
550 sym64 = find_symbol64(v64, "__kernel_datapage_offset");
551 if (sym64 == NULL) {
552 printk(KERN_ERR "vDSO64: Can't find symbol "
553 "__kernel_datapage_offset !\n");
554 return -1;
555 }
556 *((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) =
557 (vdso64_pages << PAGE_SHIFT) -
558 (sym64->st_value - VDSO64_LBASE);
559#endif /* CONFIG_PPC64 */
560
561 sym32 = find_symbol32(v32, "__kernel_datapage_offset");
562 if (sym32 == NULL) {
563 printk(KERN_ERR "vDSO32: Can't find symbol "
564 "__kernel_datapage_offset !\n");
565 return -1;
566 }
567 *((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =
568 (vdso32_pages << PAGE_SHIFT) -
569 (sym32->st_value - VDSO32_LBASE);
570
571 return 0;
572}
573
574
575static __init int vdso_fixup_features(struct lib32_elfinfo *v32,
576 struct lib64_elfinfo *v64)
577{
578 void *start32;
579 unsigned long size32;
580
581#ifdef CONFIG_PPC64
582 void *start64;
583 unsigned long size64;
584
585 start64 = find_section64(v64->hdr, "__ftr_fixup", &size64);
586 if (start64)
587 do_feature_fixups(cur_cpu_spec->cpu_features,
588 start64, start64 + size64);
589
590 start64 = find_section64(v64->hdr, "__mmu_ftr_fixup", &size64);
591 if (start64)
592 do_feature_fixups(cur_cpu_spec->mmu_features,
593 start64, start64 + size64);
594
595 start64 = find_section64(v64->hdr, "__fw_ftr_fixup", &size64);
596 if (start64)
597 do_feature_fixups(powerpc_firmware_features,
598 start64, start64 + size64);
599
600 start64 = find_section64(v64->hdr, "__lwsync_fixup", &size64);
601 if (start64)
602 do_lwsync_fixups(cur_cpu_spec->cpu_features,
603 start64, start64 + size64);
604#endif /* CONFIG_PPC64 */
605
606 start32 = find_section32(v32->hdr, "__ftr_fixup", &size32);
607 if (start32)
608 do_feature_fixups(cur_cpu_spec->cpu_features,
609 start32, start32 + size32);
610
611 start32 = find_section32(v32->hdr, "__mmu_ftr_fixup", &size32);
612 if (start32)
613 do_feature_fixups(cur_cpu_spec->mmu_features,
614 start32, start32 + size32);
615
616#ifdef CONFIG_PPC64
617 start32 = find_section32(v32->hdr, "__fw_ftr_fixup", &size32);
618 if (start32)
619 do_feature_fixups(powerpc_firmware_features,
620 start32, start32 + size32);
621#endif /* CONFIG_PPC64 */
622
623 start32 = find_section32(v32->hdr, "__lwsync_fixup", &size32);
624 if (start32)
625 do_lwsync_fixups(cur_cpu_spec->cpu_features,
626 start32, start32 + size32);
627
628 return 0;
629}
630
631static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
632 struct lib64_elfinfo *v64)
633{
634 int i;
635
636 for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
637 struct vdso_patch_def *patch = &vdso_patches[i];
638 int match = (cur_cpu_spec->cpu_features & patch->ftr_mask)
639 == patch->ftr_value;
640 if (!match)
641 continue;
642
643 DBG("replacing %s with %s...\n", patch->gen_name,
644 patch->fix_name ? "NONE" : patch->fix_name);
645
646 /*
647 * Patch the 32 bits and 64 bits symbols. Note that we do not
648 * patch the "." symbol on 64 bits.
649 * It would be easy to do, but doesn't seem to be necessary,
650 * patching the OPD symbol is enough.
651 */
652 vdso_do_func_patch32(v32, v64, patch->gen_name,
653 patch->fix_name);
654#ifdef CONFIG_PPC64
655 vdso_do_func_patch64(v32, v64, patch->gen_name,
656 patch->fix_name);
657#endif /* CONFIG_PPC64 */
658 }
659
660 return 0;
661}
662
663
664static __init int vdso_setup(void)
665{
666 struct lib32_elfinfo v32;
667 struct lib64_elfinfo v64;
668
669 v32.hdr = vdso32_kbase;
670#ifdef CONFIG_PPC64
671 v64.hdr = vdso64_kbase;
672#endif
673 if (vdso_do_find_sections(&v32, &v64))
674 return -1;
675
676 if (vdso_fixup_datapage(&v32, &v64))
677 return -1;
678
679 if (vdso_fixup_features(&v32, &v64))
680 return -1;
681
682 if (vdso_fixup_alt_funcs(&v32, &v64))
683 return -1;
684
685 vdso_setup_trampolines(&v32, &v64);
686
687 return 0;
688}
689
690/*
691 * Called from setup_arch to initialize the bitmap of available
692 * syscalls in the systemcfg page
693 */
694static void __init vdso_setup_syscall_map(void)
695{
696 unsigned int i;
697 extern unsigned long *sys_call_table;
698 extern unsigned long sys_ni_syscall;
699
700
701 for (i = 0; i < __NR_syscalls; i++) {
702#ifdef CONFIG_PPC64
703 if (sys_call_table[i*2] != sys_ni_syscall)
704 vdso_data->syscall_map_64[i >> 5] |=
705 0x80000000UL >> (i & 0x1f);
706 if (sys_call_table[i*2+1] != sys_ni_syscall)
707 vdso_data->syscall_map_32[i >> 5] |=
708 0x80000000UL >> (i & 0x1f);
709#else /* CONFIG_PPC64 */
710 if (sys_call_table[i] != sys_ni_syscall)
711 vdso_data->syscall_map_32[i >> 5] |=
712 0x80000000UL >> (i & 0x1f);
713#endif /* CONFIG_PPC64 */
714 }
715}
716
717
718static int __init vdso_init(void)
719{
720 int i;
721
722#ifdef CONFIG_PPC64
723 /*
724 * Fill up the "systemcfg" stuff for backward compatibility
725 */
726 strcpy((char *)vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
727 vdso_data->version.major = SYSTEMCFG_MAJOR;
728 vdso_data->version.minor = SYSTEMCFG_MINOR;
729 vdso_data->processor = mfspr(SPRN_PVR);
730 /*
731 * Fake the old platform number for pSeries and iSeries and add
732 * in LPAR bit if necessary
733 */
734 vdso_data->platform = machine_is(iseries) ? 0x200 : 0x100;
735 if (firmware_has_feature(FW_FEATURE_LPAR))
736 vdso_data->platform |= 1;
737 vdso_data->physicalMemorySize = memblock_phys_mem_size();
738 vdso_data->dcache_size = ppc64_caches.dsize;
739 vdso_data->dcache_line_size = ppc64_caches.dline_size;
740 vdso_data->icache_size = ppc64_caches.isize;
741 vdso_data->icache_line_size = ppc64_caches.iline_size;
742
743 /* XXXOJN: Blocks should be added to ppc64_caches and used instead */
744 vdso_data->dcache_block_size = ppc64_caches.dline_size;
745 vdso_data->icache_block_size = ppc64_caches.iline_size;
746 vdso_data->dcache_log_block_size = ppc64_caches.log_dline_size;
747 vdso_data->icache_log_block_size = ppc64_caches.log_iline_size;
748
749 /*
750 * Calculate the size of the 64 bits vDSO
751 */
752 vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
753 DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages);
754#else
755 vdso_data->dcache_block_size = L1_CACHE_BYTES;
756 vdso_data->dcache_log_block_size = L1_CACHE_SHIFT;
757 vdso_data->icache_block_size = L1_CACHE_BYTES;
758 vdso_data->icache_log_block_size = L1_CACHE_SHIFT;
759#endif /* CONFIG_PPC64 */
760
761
762 /*
763 * Calculate the size of the 32 bits vDSO
764 */
765 vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT;
766 DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase, vdso32_pages);
767
768
769 /*
770 * Setup the syscall map in the vDOS
771 */
772 vdso_setup_syscall_map();
773
774 /*
775 * Initialize the vDSO images in memory, that is do necessary
776 * fixups of vDSO symbols, locate trampolines, etc...
777 */
778 if (vdso_setup()) {
779 printk(KERN_ERR "vDSO setup failure, not enabled !\n");
780 vdso32_pages = 0;
781#ifdef CONFIG_PPC64
782 vdso64_pages = 0;
783#endif
784 return 0;
785 }
786
787 /* Make sure pages are in the correct state */
788 vdso32_pagelist = kzalloc(sizeof(struct page *) * (vdso32_pages + 2),
789 GFP_KERNEL);
790 BUG_ON(vdso32_pagelist == NULL);
791 for (i = 0; i < vdso32_pages; i++) {
792 struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
793 ClearPageReserved(pg);
794 get_page(pg);
795 vdso32_pagelist[i] = pg;
796 }
797 vdso32_pagelist[i++] = virt_to_page(vdso_data);
798 vdso32_pagelist[i] = NULL;
799
800#ifdef CONFIG_PPC64
801 vdso64_pagelist = kzalloc(sizeof(struct page *) * (vdso64_pages + 2),
802 GFP_KERNEL);
803 BUG_ON(vdso64_pagelist == NULL);
804 for (i = 0; i < vdso64_pages; i++) {
805 struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
806 ClearPageReserved(pg);
807 get_page(pg);
808 vdso64_pagelist[i] = pg;
809 }
810 vdso64_pagelist[i++] = virt_to_page(vdso_data);
811 vdso64_pagelist[i] = NULL;
812#endif /* CONFIG_PPC64 */
813
814 get_page(virt_to_page(vdso_data));
815
816 smp_wmb();
817 vdso_ready = 1;
818
819 return 0;
820}
821arch_initcall(vdso_init);
822
823int in_gate_area_no_mm(unsigned long addr)
824{
825 return 0;
826}
827
828int in_gate_area(struct mm_struct *mm, unsigned long addr)
829{
830 return 0;
831}
832
833struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
834{
835 return NULL;
836}
837