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v6.8
  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		if (vma_is_special_mapping(vma, &vvar_spec))
124			zap_vma_pages(vma);
125	}
126	mmap_read_unlock(mm);
127
 
128	return 0;
129}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
130#endif
131
132static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
133			     struct vm_area_struct *vma, struct vm_fault *vmf)
134{
135	struct page *timens_page = find_timens_vvar_page(vma);
136	unsigned long pfn;
137
138	switch (vmf->pgoff) {
139	case VVAR_DATA_PAGE_OFFSET:
140		if (timens_page)
141			pfn = page_to_pfn(timens_page);
142		else
143			pfn = virt_to_pfn(vdso_data);
144		break;
145#ifdef CONFIG_TIME_NS
146	case VVAR_TIMENS_PAGE_OFFSET:
147		/*
148		 * If a task belongs to a time namespace then a namespace
149		 * specific VVAR is mapped with the VVAR_DATA_PAGE_OFFSET and
150		 * the real VVAR page is mapped with the VVAR_TIMENS_PAGE_OFFSET
151		 * offset.
152		 * See also the comment near timens_setup_vdso_data().
153		 */
154		if (!timens_page)
155			return VM_FAULT_SIGBUS;
156		pfn = virt_to_pfn(vdso_data);
157		break;
158#endif /* CONFIG_TIME_NS */
159	default:
160		return VM_FAULT_SIGBUS;
161	}
162
163	return vmf_insert_pfn(vma, vmf->address, pfn);
164}
165
166/*
167 * This is called from binfmt_elf, we create the special vma for the
168 * vDSO and insert it into the mm struct tree
169 */
170static int __arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
171{
172	unsigned long vdso_size, vdso_base, mappings_size;
173	struct vm_special_mapping *vdso_spec;
174	unsigned long vvar_size = VVAR_NR_PAGES * PAGE_SIZE;
175	struct mm_struct *mm = current->mm;
176	struct vm_area_struct *vma;
177
178	if (is_32bit_task()) {
179		vdso_spec = &vdso32_spec;
180		vdso_size = &vdso32_end - &vdso32_start;
 
181	} else {
182		vdso_spec = &vdso64_spec;
183		vdso_size = &vdso64_end - &vdso64_start;
 
 
 
 
 
 
184	}
185
186	mappings_size = vdso_size + vvar_size;
187	mappings_size += (VDSO_ALIGNMENT - 1) & PAGE_MASK;
188
189	/*
190	 * Pick a base address for the vDSO in process space.
 
 
191	 * Add enough to the size so that the result can be aligned.
192	 */
193	vdso_base = get_unmapped_area(NULL, 0, mappings_size, 0, 0);
194	if (IS_ERR_VALUE(vdso_base))
195		return vdso_base;
196
197	/* Add required alignment. */
198	vdso_base = ALIGN(vdso_base, VDSO_ALIGNMENT);
199
200	/*
201	 * Put vDSO base into mm struct. We need to do this before calling
202	 * install_special_mapping or the perf counter mmap tracking code
203	 * will fail to recognise it as a vDSO.
204	 */
205	mm->context.vdso = (void __user *)vdso_base + vvar_size;
206
207	vma = _install_special_mapping(mm, vdso_base, vvar_size,
208				       VM_READ | VM_MAYREAD | VM_IO |
209				       VM_DONTDUMP | VM_PFNMAP, &vvar_spec);
210	if (IS_ERR(vma))
211		return PTR_ERR(vma);
212
213	/*
214	 * our vma flags don't have VM_WRITE so by default, the process isn't
215	 * allowed to write those pages.
216	 * gdb can break that with ptrace interface, and thus trigger COW on
217	 * those pages but it's then your responsibility to never do that on
218	 * the "data" page of the vDSO or you'll stop getting kernel updates
219	 * and your nice userland gettimeofday will be totally dead.
220	 * It's fine to use that for setting breakpoints in the vDSO code
221	 * pages though.
222	 */
223	vma = _install_special_mapping(mm, vdso_base + vvar_size, vdso_size,
224				       VM_READ | VM_EXEC | VM_MAYREAD |
225				       VM_MAYWRITE | VM_MAYEXEC, vdso_spec);
226	if (IS_ERR(vma))
227		do_munmap(mm, vdso_base, vvar_size, NULL);
228
229	return PTR_ERR_OR_ZERO(vma);
230}
231
232int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
233{
234	struct mm_struct *mm = current->mm;
235	int rc;
236
237	mm->context.vdso = NULL;
238
239	if (mmap_write_lock_killable(mm))
240		return -EINTR;
241
242	rc = __arch_setup_additional_pages(bprm, uses_interp);
243	if (rc)
244		mm->context.vdso = NULL;
245
246	mmap_write_unlock(mm);
247	return rc;
248}
249
250#define VDSO_DO_FIXUPS(type, value, bits, sec) do {					\
251	void *__start = (void *)VDSO##bits##_SYMBOL(&vdso##bits##_start, sec##_start);	\
252	void *__end = (void *)VDSO##bits##_SYMBOL(&vdso##bits##_start, sec##_end);	\
253											\
254	do_##type##_fixups((value), __start, __end);					\
255} while (0)
256
257static void __init vdso_fixup_features(void)
258{
259#ifdef CONFIG_PPC64
260	VDSO_DO_FIXUPS(feature, cur_cpu_spec->cpu_features, 64, ftr_fixup);
261	VDSO_DO_FIXUPS(feature, cur_cpu_spec->mmu_features, 64, mmu_ftr_fixup);
262	VDSO_DO_FIXUPS(feature, powerpc_firmware_features, 64, fw_ftr_fixup);
263	VDSO_DO_FIXUPS(lwsync, cur_cpu_spec->cpu_features, 64, lwsync_fixup);
264#endif /* CONFIG_PPC64 */
265
266#ifdef CONFIG_VDSO32
267	VDSO_DO_FIXUPS(feature, cur_cpu_spec->cpu_features, 32, ftr_fixup);
268	VDSO_DO_FIXUPS(feature, cur_cpu_spec->mmu_features, 32, mmu_ftr_fixup);
269#ifdef CONFIG_PPC64
270	VDSO_DO_FIXUPS(feature, powerpc_firmware_features, 32, fw_ftr_fixup);
271#endif /* CONFIG_PPC64 */
272	VDSO_DO_FIXUPS(lwsync, cur_cpu_spec->cpu_features, 32, lwsync_fixup);
273#endif
274}
275
276/*
277 * Called from setup_arch to initialize the bitmap of available
278 * syscalls in the systemcfg page
279 */
280static void __init vdso_setup_syscall_map(void)
281{
282	unsigned int i;
283
284	for (i = 0; i < NR_syscalls; i++) {
285		if (sys_call_table[i] != (void *)&sys_ni_syscall)
286			vdso_data->syscall_map[i >> 5] |= 0x80000000UL >> (i & 0x1f);
287		if (IS_ENABLED(CONFIG_COMPAT) &&
288		    compat_sys_call_table[i] != (void *)&sys_ni_syscall)
289			vdso_data->compat_syscall_map[i >> 5] |= 0x80000000UL >> (i & 0x1f);
290	}
291}
292
293#ifdef CONFIG_PPC64
294int vdso_getcpu_init(void)
295{
296	unsigned long cpu, node, val;
297
298	/*
299	 * SPRG_VDSO contains the CPU in the bottom 16 bits and the NUMA node
300	 * in the next 16 bits.  The VDSO uses this to implement getcpu().
301	 */
302	cpu = get_cpu();
303	WARN_ON_ONCE(cpu > 0xffff);
304
305	node = cpu_to_node(cpu);
306	WARN_ON_ONCE(node > 0xffff);
307
308	val = (cpu & 0xffff) | ((node & 0xffff) << 16);
309	mtspr(SPRN_SPRG_VDSO_WRITE, val);
310	get_paca()->sprg_vdso = val;
311
312	put_cpu();
313
314	return 0;
315}
316/* We need to call this before SMP init */
317early_initcall(vdso_getcpu_init);
318#endif
319
320static struct page ** __init vdso_setup_pages(void *start, void *end)
321{
322	int i;
323	struct page **pagelist;
324	int pages = (end - start) >> PAGE_SHIFT;
325
326	pagelist = kcalloc(pages + 1, sizeof(struct page *), GFP_KERNEL);
327	if (!pagelist)
328		panic("%s: Cannot allocate page list for VDSO", __func__);
329
330	for (i = 0; i < pages; i++)
331		pagelist[i] = virt_to_page(start + i * PAGE_SIZE);
332
333	return pagelist;
334}
335
336static int __init vdso_init(void)
337{
338#ifdef CONFIG_PPC64
339	/*
340	 * Fill up the "systemcfg" stuff for backward compatibility
341	 */
342	strcpy((char *)vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
343	vdso_data->version.major = SYSTEMCFG_MAJOR;
344	vdso_data->version.minor = SYSTEMCFG_MINOR;
345	vdso_data->processor = mfspr(SPRN_PVR);
346	/*
347	 * Fake the old platform number for pSeries and add
348	 * in LPAR bit if necessary
349	 */
350	vdso_data->platform = 0x100;
351	if (firmware_has_feature(FW_FEATURE_LPAR))
352		vdso_data->platform |= 1;
353	vdso_data->physicalMemorySize = memblock_phys_mem_size();
354	vdso_data->dcache_size = ppc64_caches.l1d.size;
355	vdso_data->dcache_line_size = ppc64_caches.l1d.line_size;
356	vdso_data->icache_size = ppc64_caches.l1i.size;
357	vdso_data->icache_line_size = ppc64_caches.l1i.line_size;
358	vdso_data->dcache_block_size = ppc64_caches.l1d.block_size;
359	vdso_data->icache_block_size = ppc64_caches.l1i.block_size;
360	vdso_data->dcache_log_block_size = ppc64_caches.l1d.log_block_size;
361	vdso_data->icache_log_block_size = ppc64_caches.l1i.log_block_size;
362#endif /* CONFIG_PPC64 */
363
364	vdso_setup_syscall_map();
365
366	vdso_fixup_features();
367
368	if (IS_ENABLED(CONFIG_VDSO32))
369		vdso32_spec.pages = vdso_setup_pages(&vdso32_start, &vdso32_end);
370
371	if (IS_ENABLED(CONFIG_PPC64))
372		vdso64_spec.pages = vdso_setup_pages(&vdso64_start, &vdso64_end);
373
374	smp_wmb();
375
376	return 0;
377}
378arch_initcall(vdso_init);
v5.14.15
  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/prom.h>
 29#include <asm/machdep.h>
 30#include <asm/cputable.h>
 31#include <asm/sections.h>
 32#include <asm/firmware.h>
 33#include <asm/vdso.h>
 34#include <asm/vdso_datapage.h>
 35#include <asm/setup.h>
 36
 37/* The alignment of the vDSO */
 38#define VDSO_ALIGNMENT	(1 << 16)
 39
 40extern char vdso32_start, vdso32_end;
 41extern char vdso64_start, vdso64_end;
 42
 
 
 43/*
 44 * The vdso data page (aka. systemcfg for old ppc64 fans) is here.
 45 * Once the early boot kernel code no longer needs to muck around
 46 * with it, it will become dynamically allocated
 47 */
 48static union {
 49	struct vdso_arch_data	data;
 50	u8			page[PAGE_SIZE];
 51} vdso_data_store __page_aligned_data;
 52struct vdso_arch_data *vdso_data = &vdso_data_store.data;
 53
 54enum vvar_pages {
 55	VVAR_DATA_PAGE_OFFSET,
 56	VVAR_TIMENS_PAGE_OFFSET,
 57	VVAR_NR_PAGES,
 58};
 59
 60static int vdso_mremap(const struct vm_special_mapping *sm, struct vm_area_struct *new_vma,
 61		       unsigned long text_size)
 62{
 63	unsigned long new_size = new_vma->vm_end - new_vma->vm_start;
 64
 65	if (new_size != text_size)
 66		return -EINVAL;
 67
 68	current->mm->context.vdso = (void __user *)new_vma->vm_start;
 69
 70	return 0;
 71}
 72
 73static int vdso32_mremap(const struct vm_special_mapping *sm, struct vm_area_struct *new_vma)
 74{
 75	return vdso_mremap(sm, new_vma, &vdso32_end - &vdso32_start);
 76}
 77
 78static int vdso64_mremap(const struct vm_special_mapping *sm, struct vm_area_struct *new_vma)
 79{
 80	return vdso_mremap(sm, new_vma, &vdso64_end - &vdso64_start);
 81}
 82
 83static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
 84			     struct vm_area_struct *vma, struct vm_fault *vmf);
 85
 86static struct vm_special_mapping vvar_spec __ro_after_init = {
 87	.name = "[vvar]",
 88	.fault = vvar_fault,
 89};
 90
 91static struct vm_special_mapping vdso32_spec __ro_after_init = {
 92	.name = "[vdso]",
 93	.mremap = vdso32_mremap,
 94};
 95
 96static struct vm_special_mapping vdso64_spec __ro_after_init = {
 97	.name = "[vdso]",
 98	.mremap = vdso64_mremap,
 99};
100
101#ifdef CONFIG_TIME_NS
102struct vdso_data *arch_get_vdso_data(void *vvar_page)
103{
104	return ((struct vdso_arch_data *)vvar_page)->data;
105}
106
107/*
108 * The vvar mapping contains data for a specific time namespace, so when a task
109 * changes namespace we must unmap its vvar data for the old namespace.
110 * Subsequent faults will map in data for the new namespace.
111 *
112 * For more details see timens_setup_vdso_data().
113 */
114int vdso_join_timens(struct task_struct *task, struct time_namespace *ns)
115{
116	struct mm_struct *mm = task->mm;
 
117	struct vm_area_struct *vma;
118
119	mmap_read_lock(mm);
120
121	for (vma = mm->mmap; vma; vma = vma->vm_next) {
122		unsigned long size = vma->vm_end - vma->vm_start;
123
124		if (vma_is_special_mapping(vma, &vvar_spec))
125			zap_page_range(vma, vma->vm_start, size);
126	}
 
127
128	mmap_read_unlock(mm);
129	return 0;
130}
131
132static struct page *find_timens_vvar_page(struct vm_area_struct *vma)
133{
134	if (likely(vma->vm_mm == current->mm))
135		return current->nsproxy->time_ns->vvar_page;
136
137	/*
138	 * VM_PFNMAP | VM_IO protect .fault() handler from being called
139	 * through interfaces like /proc/$pid/mem or
140	 * process_vm_{readv,writev}() as long as there's no .access()
141	 * in special_mapping_vmops.
142	 * For more details check_vma_flags() and __access_remote_vm()
143	 */
144	WARN(1, "vvar_page accessed remotely");
145
146	return NULL;
147}
148#else
149static struct page *find_timens_vvar_page(struct vm_area_struct *vma)
150{
151	return NULL;
152}
153#endif
154
155static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
156			     struct vm_area_struct *vma, struct vm_fault *vmf)
157{
158	struct page *timens_page = find_timens_vvar_page(vma);
159	unsigned long pfn;
160
161	switch (vmf->pgoff) {
162	case VVAR_DATA_PAGE_OFFSET:
163		if (timens_page)
164			pfn = page_to_pfn(timens_page);
165		else
166			pfn = virt_to_pfn(vdso_data);
167		break;
168#ifdef CONFIG_TIME_NS
169	case VVAR_TIMENS_PAGE_OFFSET:
170		/*
171		 * If a task belongs to a time namespace then a namespace
172		 * specific VVAR is mapped with the VVAR_DATA_PAGE_OFFSET and
173		 * the real VVAR page is mapped with the VVAR_TIMENS_PAGE_OFFSET
174		 * offset.
175		 * See also the comment near timens_setup_vdso_data().
176		 */
177		if (!timens_page)
178			return VM_FAULT_SIGBUS;
179		pfn = virt_to_pfn(vdso_data);
180		break;
181#endif /* CONFIG_TIME_NS */
182	default:
183		return VM_FAULT_SIGBUS;
184	}
185
186	return vmf_insert_pfn(vma, vmf->address, pfn);
187}
188
189/*
190 * This is called from binfmt_elf, we create the special vma for the
191 * vDSO and insert it into the mm struct tree
192 */
193static int __arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
194{
195	unsigned long vdso_size, vdso_base, mappings_size;
196	struct vm_special_mapping *vdso_spec;
197	unsigned long vvar_size = VVAR_NR_PAGES * PAGE_SIZE;
198	struct mm_struct *mm = current->mm;
199	struct vm_area_struct *vma;
200
201	if (is_32bit_task()) {
202		vdso_spec = &vdso32_spec;
203		vdso_size = &vdso32_end - &vdso32_start;
204		vdso_base = VDSO32_MBASE;
205	} else {
206		vdso_spec = &vdso64_spec;
207		vdso_size = &vdso64_end - &vdso64_start;
208		/*
209		 * On 64bit we don't have a preferred map address. This
210		 * allows get_unmapped_area to find an area near other mmaps
211		 * and most likely share a SLB entry.
212		 */
213		vdso_base = 0;
214	}
215
216	mappings_size = vdso_size + vvar_size;
217	mappings_size += (VDSO_ALIGNMENT - 1) & PAGE_MASK;
218
219	/*
220	 * pick a base address for the vDSO in process space. We try to put it
221	 * at vdso_base which is the "natural" base for it, but we might fail
222	 * and end up putting it elsewhere.
223	 * Add enough to the size so that the result can be aligned.
224	 */
225	vdso_base = get_unmapped_area(NULL, vdso_base, mappings_size, 0, 0);
226	if (IS_ERR_VALUE(vdso_base))
227		return vdso_base;
228
229	/* Add required alignment. */
230	vdso_base = ALIGN(vdso_base, VDSO_ALIGNMENT);
231
232	/*
233	 * Put vDSO base into mm struct. We need to do this before calling
234	 * install_special_mapping or the perf counter mmap tracking code
235	 * will fail to recognise it as a vDSO.
236	 */
237	mm->context.vdso = (void __user *)vdso_base + vvar_size;
238
239	vma = _install_special_mapping(mm, vdso_base, vvar_size,
240				       VM_READ | VM_MAYREAD | VM_IO |
241				       VM_DONTDUMP | VM_PFNMAP, &vvar_spec);
242	if (IS_ERR(vma))
243		return PTR_ERR(vma);
244
245	/*
246	 * our vma flags don't have VM_WRITE so by default, the process isn't
247	 * allowed to write those pages.
248	 * gdb can break that with ptrace interface, and thus trigger COW on
249	 * those pages but it's then your responsibility to never do that on
250	 * the "data" page of the vDSO or you'll stop getting kernel updates
251	 * and your nice userland gettimeofday will be totally dead.
252	 * It's fine to use that for setting breakpoints in the vDSO code
253	 * pages though.
254	 */
255	vma = _install_special_mapping(mm, vdso_base + vvar_size, vdso_size,
256				       VM_READ | VM_EXEC | VM_MAYREAD |
257				       VM_MAYWRITE | VM_MAYEXEC, vdso_spec);
258	if (IS_ERR(vma))
259		do_munmap(mm, vdso_base, vvar_size, NULL);
260
261	return PTR_ERR_OR_ZERO(vma);
262}
263
264int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
265{
266	struct mm_struct *mm = current->mm;
267	int rc;
268
269	mm->context.vdso = NULL;
270
271	if (mmap_write_lock_killable(mm))
272		return -EINTR;
273
274	rc = __arch_setup_additional_pages(bprm, uses_interp);
275	if (rc)
276		mm->context.vdso = NULL;
277
278	mmap_write_unlock(mm);
279	return rc;
280}
281
282#define VDSO_DO_FIXUPS(type, value, bits, sec) do {					\
283	void *__start = (void *)VDSO##bits##_SYMBOL(&vdso##bits##_start, sec##_start);	\
284	void *__end = (void *)VDSO##bits##_SYMBOL(&vdso##bits##_start, sec##_end);	\
285											\
286	do_##type##_fixups((value), __start, __end);					\
287} while (0)
288
289static void __init vdso_fixup_features(void)
290{
291#ifdef CONFIG_PPC64
292	VDSO_DO_FIXUPS(feature, cur_cpu_spec->cpu_features, 64, ftr_fixup);
293	VDSO_DO_FIXUPS(feature, cur_cpu_spec->mmu_features, 64, mmu_ftr_fixup);
294	VDSO_DO_FIXUPS(feature, powerpc_firmware_features, 64, fw_ftr_fixup);
295	VDSO_DO_FIXUPS(lwsync, cur_cpu_spec->cpu_features, 64, lwsync_fixup);
296#endif /* CONFIG_PPC64 */
297
298#ifdef CONFIG_VDSO32
299	VDSO_DO_FIXUPS(feature, cur_cpu_spec->cpu_features, 32, ftr_fixup);
300	VDSO_DO_FIXUPS(feature, cur_cpu_spec->mmu_features, 32, mmu_ftr_fixup);
301#ifdef CONFIG_PPC64
302	VDSO_DO_FIXUPS(feature, powerpc_firmware_features, 32, fw_ftr_fixup);
303#endif /* CONFIG_PPC64 */
304	VDSO_DO_FIXUPS(lwsync, cur_cpu_spec->cpu_features, 32, lwsync_fixup);
305#endif
306}
307
308/*
309 * Called from setup_arch to initialize the bitmap of available
310 * syscalls in the systemcfg page
311 */
312static void __init vdso_setup_syscall_map(void)
313{
314	unsigned int i;
315
316	for (i = 0; i < NR_syscalls; i++) {
317		if (sys_call_table[i] != (unsigned long)&sys_ni_syscall)
318			vdso_data->syscall_map[i >> 5] |= 0x80000000UL >> (i & 0x1f);
319		if (IS_ENABLED(CONFIG_COMPAT) &&
320		    compat_sys_call_table[i] != (unsigned long)&sys_ni_syscall)
321			vdso_data->compat_syscall_map[i >> 5] |= 0x80000000UL >> (i & 0x1f);
322	}
323}
324
325#ifdef CONFIG_PPC64
326int vdso_getcpu_init(void)
327{
328	unsigned long cpu, node, val;
329
330	/*
331	 * SPRG_VDSO contains the CPU in the bottom 16 bits and the NUMA node
332	 * in the next 16 bits.  The VDSO uses this to implement getcpu().
333	 */
334	cpu = get_cpu();
335	WARN_ON_ONCE(cpu > 0xffff);
336
337	node = cpu_to_node(cpu);
338	WARN_ON_ONCE(node > 0xffff);
339
340	val = (cpu & 0xffff) | ((node & 0xffff) << 16);
341	mtspr(SPRN_SPRG_VDSO_WRITE, val);
342	get_paca()->sprg_vdso = val;
343
344	put_cpu();
345
346	return 0;
347}
348/* We need to call this before SMP init */
349early_initcall(vdso_getcpu_init);
350#endif
351
352static struct page ** __init vdso_setup_pages(void *start, void *end)
353{
354	int i;
355	struct page **pagelist;
356	int pages = (end - start) >> PAGE_SHIFT;
357
358	pagelist = kcalloc(pages + 1, sizeof(struct page *), GFP_KERNEL);
359	if (!pagelist)
360		panic("%s: Cannot allocate page list for VDSO", __func__);
361
362	for (i = 0; i < pages; i++)
363		pagelist[i] = virt_to_page(start + i * PAGE_SIZE);
364
365	return pagelist;
366}
367
368static int __init vdso_init(void)
369{
370#ifdef CONFIG_PPC64
371	/*
372	 * Fill up the "systemcfg" stuff for backward compatibility
373	 */
374	strcpy((char *)vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
375	vdso_data->version.major = SYSTEMCFG_MAJOR;
376	vdso_data->version.minor = SYSTEMCFG_MINOR;
377	vdso_data->processor = mfspr(SPRN_PVR);
378	/*
379	 * Fake the old platform number for pSeries and add
380	 * in LPAR bit if necessary
381	 */
382	vdso_data->platform = 0x100;
383	if (firmware_has_feature(FW_FEATURE_LPAR))
384		vdso_data->platform |= 1;
385	vdso_data->physicalMemorySize = memblock_phys_mem_size();
386	vdso_data->dcache_size = ppc64_caches.l1d.size;
387	vdso_data->dcache_line_size = ppc64_caches.l1d.line_size;
388	vdso_data->icache_size = ppc64_caches.l1i.size;
389	vdso_data->icache_line_size = ppc64_caches.l1i.line_size;
390	vdso_data->dcache_block_size = ppc64_caches.l1d.block_size;
391	vdso_data->icache_block_size = ppc64_caches.l1i.block_size;
392	vdso_data->dcache_log_block_size = ppc64_caches.l1d.log_block_size;
393	vdso_data->icache_log_block_size = ppc64_caches.l1i.log_block_size;
394#endif /* CONFIG_PPC64 */
395
396	vdso_setup_syscall_map();
397
398	vdso_fixup_features();
399
400	if (IS_ENABLED(CONFIG_VDSO32))
401		vdso32_spec.pages = vdso_setup_pages(&vdso32_start, &vdso32_end);
402
403	if (IS_ENABLED(CONFIG_PPC64))
404		vdso64_spec.pages = vdso_setup_pages(&vdso64_start, &vdso64_end);
405
406	smp_wmb();
407
408	return 0;
409}
410arch_initcall(vdso_init);