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1da177e4 LT |
1 | /* |
2 | * IA-32 ELF support. | |
3 | * | |
4 | * Copyright (C) 1999 Arun Sharma <arun.sharma@intel.com> | |
5 | * Copyright (C) 2001 Hewlett-Packard Co | |
6 | * David Mosberger-Tang <davidm@hpl.hp.com> | |
7 | * | |
8 | * 06/16/00 A. Mallick initialize csd/ssd/tssd/cflg for ia32_load_state | |
9 | * 04/13/01 D. Mosberger dropped saving tssd in ar.k1---it's not needed | |
10 | * 09/14/01 D. Mosberger fixed memory management for gdt/tss page | |
11 | */ | |
1da177e4 LT |
12 | |
13 | #include <linux/types.h> | |
14 | #include <linux/mm.h> | |
15 | #include <linux/security.h> | |
16 | ||
17 | #include <asm/param.h> | |
18 | #include <asm/signal.h> | |
19 | ||
20 | #include "ia32priv.h" | |
21 | #include "elfcore32.h" | |
22 | ||
23 | /* Override some function names */ | |
24 | #undef start_thread | |
25 | #define start_thread ia32_start_thread | |
26 | #define elf_format elf32_format | |
27 | #define init_elf_binfmt init_elf32_binfmt | |
28 | #define exit_elf_binfmt exit_elf32_binfmt | |
29 | ||
30 | #undef CLOCKS_PER_SEC | |
31 | #define CLOCKS_PER_SEC IA32_CLOCKS_PER_SEC | |
32 | ||
33 | extern void ia64_elf32_init (struct pt_regs *regs); | |
34 | ||
35 | static void elf32_set_personality (void); | |
36 | ||
ee6d4b6e ST |
37 | static unsigned long __attribute ((unused)) |
38 | randomize_stack_top(unsigned long stack_top); | |
39 | ||
1da177e4 LT |
40 | #define setup_arg_pages(bprm,tos,exec) ia32_setup_arg_pages(bprm,exec) |
41 | #define elf_map elf32_map | |
42 | ||
43 | #undef SET_PERSONALITY | |
44 | #define SET_PERSONALITY(ex, ibcs2) elf32_set_personality() | |
45 | ||
46 | #define elf_read_implies_exec(ex, have_pt_gnu_stack) (!(have_pt_gnu_stack)) | |
47 | ||
48 | /* Ugly but avoids duplication */ | |
49 | #include "../../../fs/binfmt_elf.c" | |
50 | ||
51 | extern struct page *ia32_shared_page[]; | |
52 | extern unsigned long *ia32_gdt; | |
53 | extern struct page *ia32_gate_page; | |
54 | ||
55 | struct page * | |
56 | ia32_install_shared_page (struct vm_area_struct *vma, unsigned long address, int *type) | |
57 | { | |
58 | struct page *pg = ia32_shared_page[smp_processor_id()]; | |
59 | get_page(pg); | |
60 | if (type) | |
61 | *type = VM_FAULT_MINOR; | |
62 | return pg; | |
63 | } | |
64 | ||
65 | struct page * | |
66 | ia32_install_gate_page (struct vm_area_struct *vma, unsigned long address, int *type) | |
67 | { | |
68 | struct page *pg = ia32_gate_page; | |
69 | get_page(pg); | |
70 | if (type) | |
71 | *type = VM_FAULT_MINOR; | |
72 | return pg; | |
73 | } | |
74 | ||
75 | ||
76 | static struct vm_operations_struct ia32_shared_page_vm_ops = { | |
77 | .nopage = ia32_install_shared_page | |
78 | }; | |
79 | ||
80 | static struct vm_operations_struct ia32_gate_page_vm_ops = { | |
81 | .nopage = ia32_install_gate_page | |
82 | }; | |
83 | ||
84 | void | |
85 | ia64_elf32_init (struct pt_regs *regs) | |
86 | { | |
87 | struct vm_area_struct *vma; | |
88 | ||
89 | /* | |
90 | * Map GDT below 4GB, where the processor can find it. We need to map | |
91 | * it with privilege level 3 because the IVE uses non-privileged accesses to these | |
92 | * tables. IA-32 segmentation is used to protect against IA-32 accesses to them. | |
93 | */ | |
e94b1766 | 94 | vma = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL); |
1da177e4 LT |
95 | if (vma) { |
96 | memset(vma, 0, sizeof(*vma)); | |
97 | vma->vm_mm = current->mm; | |
98 | vma->vm_start = IA32_GDT_OFFSET; | |
99 | vma->vm_end = vma->vm_start + PAGE_SIZE; | |
100 | vma->vm_page_prot = PAGE_SHARED; | |
101 | vma->vm_flags = VM_READ|VM_MAYREAD|VM_RESERVED; | |
102 | vma->vm_ops = &ia32_shared_page_vm_ops; | |
103 | down_write(¤t->mm->mmap_sem); | |
104 | { | |
105 | if (insert_vm_struct(current->mm, vma)) { | |
106 | kmem_cache_free(vm_area_cachep, vma); | |
107 | up_write(¤t->mm->mmap_sem); | |
108 | BUG(); | |
109 | } | |
110 | } | |
111 | up_write(¤t->mm->mmap_sem); | |
112 | } | |
113 | ||
114 | /* | |
115 | * When user stack is not executable, push sigreturn code to stack makes | |
116 | * segmentation fault raised when returning to kernel. So now sigreturn | |
117 | * code is locked in specific gate page, which is pointed by pretcode | |
118 | * when setup_frame_ia32 | |
119 | */ | |
e94b1766 | 120 | vma = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL); |
1da177e4 LT |
121 | if (vma) { |
122 | memset(vma, 0, sizeof(*vma)); | |
123 | vma->vm_mm = current->mm; | |
124 | vma->vm_start = IA32_GATE_OFFSET; | |
125 | vma->vm_end = vma->vm_start + PAGE_SIZE; | |
126 | vma->vm_page_prot = PAGE_COPY_EXEC; | |
127 | vma->vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | |
128 | | VM_MAYEXEC | VM_RESERVED; | |
129 | vma->vm_ops = &ia32_gate_page_vm_ops; | |
130 | down_write(¤t->mm->mmap_sem); | |
131 | { | |
132 | if (insert_vm_struct(current->mm, vma)) { | |
133 | kmem_cache_free(vm_area_cachep, vma); | |
134 | up_write(¤t->mm->mmap_sem); | |
135 | BUG(); | |
136 | } | |
137 | } | |
138 | up_write(¤t->mm->mmap_sem); | |
139 | } | |
140 | ||
141 | /* | |
142 | * Install LDT as anonymous memory. This gives us all-zero segment descriptors | |
143 | * until a task modifies them via modify_ldt(). | |
144 | */ | |
e94b1766 | 145 | vma = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL); |
1da177e4 LT |
146 | if (vma) { |
147 | memset(vma, 0, sizeof(*vma)); | |
148 | vma->vm_mm = current->mm; | |
149 | vma->vm_start = IA32_LDT_OFFSET; | |
150 | vma->vm_end = vma->vm_start + PAGE_ALIGN(IA32_LDT_ENTRIES*IA32_LDT_ENTRY_SIZE); | |
151 | vma->vm_page_prot = PAGE_SHARED; | |
152 | vma->vm_flags = VM_READ|VM_WRITE|VM_MAYREAD|VM_MAYWRITE; | |
153 | down_write(¤t->mm->mmap_sem); | |
154 | { | |
155 | if (insert_vm_struct(current->mm, vma)) { | |
156 | kmem_cache_free(vm_area_cachep, vma); | |
157 | up_write(¤t->mm->mmap_sem); | |
158 | BUG(); | |
159 | } | |
160 | } | |
161 | up_write(¤t->mm->mmap_sem); | |
162 | } | |
163 | ||
164 | ia64_psr(regs)->ac = 0; /* turn off alignment checking */ | |
165 | regs->loadrs = 0; | |
166 | /* | |
167 | * According to the ABI %edx points to an `atexit' handler. Since we don't have | |
168 | * one we'll set it to 0 and initialize all the other registers just to make | |
169 | * things more deterministic, ala the i386 implementation. | |
170 | */ | |
171 | regs->r8 = 0; /* %eax */ | |
172 | regs->r11 = 0; /* %ebx */ | |
173 | regs->r9 = 0; /* %ecx */ | |
174 | regs->r10 = 0; /* %edx */ | |
175 | regs->r13 = 0; /* %ebp */ | |
176 | regs->r14 = 0; /* %esi */ | |
177 | regs->r15 = 0; /* %edi */ | |
178 | ||
179 | current->thread.eflag = IA32_EFLAG; | |
180 | current->thread.fsr = IA32_FSR_DEFAULT; | |
181 | current->thread.fcr = IA32_FCR_DEFAULT; | |
182 | current->thread.fir = 0; | |
183 | current->thread.fdr = 0; | |
184 | ||
185 | /* | |
186 | * Setup GDTD. Note: GDTD is the descrambled version of the pseudo-descriptor | |
187 | * format defined by Figure 3-11 "Pseudo-Descriptor Format" in the IA-32 | |
188 | * architecture manual. Also note that the only fields that are not ignored are | |
189 | * `base', `limit', 'G', `P' (must be 1) and `S' (must be 0). | |
190 | */ | |
191 | regs->r31 = IA32_SEG_UNSCRAMBLE(IA32_SEG_DESCRIPTOR(IA32_GDT_OFFSET, IA32_PAGE_SIZE - 1, | |
192 | 0, 0, 0, 1, 0, 0, 0)); | |
193 | /* Setup the segment selectors */ | |
194 | regs->r16 = (__USER_DS << 16) | __USER_DS; /* ES == DS, GS, FS are zero */ | |
195 | regs->r17 = (__USER_DS << 16) | __USER_CS; /* SS, CS; ia32_load_state() sets TSS and LDT */ | |
196 | ||
197 | ia32_load_segment_descriptors(current); | |
198 | ia32_load_state(current); | |
199 | } | |
200 | ||
201 | int | |
202 | ia32_setup_arg_pages (struct linux_binprm *bprm, int executable_stack) | |
203 | { | |
204 | unsigned long stack_base; | |
205 | struct vm_area_struct *mpnt; | |
206 | struct mm_struct *mm = current->mm; | |
207 | int i, ret; | |
208 | ||
209 | stack_base = IA32_STACK_TOP - MAX_ARG_PAGES*PAGE_SIZE; | |
210 | mm->arg_start = bprm->p + stack_base; | |
211 | ||
212 | bprm->p += stack_base; | |
213 | if (bprm->loader) | |
214 | bprm->loader += stack_base; | |
215 | bprm->exec += stack_base; | |
216 | ||
e94b1766 | 217 | mpnt = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL); |
1da177e4 LT |
218 | if (!mpnt) |
219 | return -ENOMEM; | |
220 | ||
1da177e4 LT |
221 | memset(mpnt, 0, sizeof(*mpnt)); |
222 | ||
223 | down_write(¤t->mm->mmap_sem); | |
224 | { | |
225 | mpnt->vm_mm = current->mm; | |
226 | mpnt->vm_start = PAGE_MASK & (unsigned long) bprm->p; | |
227 | mpnt->vm_end = IA32_STACK_TOP; | |
228 | if (executable_stack == EXSTACK_ENABLE_X) | |
229 | mpnt->vm_flags = VM_STACK_FLAGS | VM_EXEC; | |
230 | else if (executable_stack == EXSTACK_DISABLE_X) | |
231 | mpnt->vm_flags = VM_STACK_FLAGS & ~VM_EXEC; | |
232 | else | |
233 | mpnt->vm_flags = VM_STACK_FLAGS; | |
234 | mpnt->vm_page_prot = (mpnt->vm_flags & VM_EXEC)? | |
235 | PAGE_COPY_EXEC: PAGE_COPY; | |
236 | if ((ret = insert_vm_struct(current->mm, mpnt))) { | |
237 | up_write(¤t->mm->mmap_sem); | |
238 | kmem_cache_free(vm_area_cachep, mpnt); | |
239 | return ret; | |
240 | } | |
241 | current->mm->stack_vm = current->mm->total_vm = vma_pages(mpnt); | |
242 | } | |
243 | ||
244 | for (i = 0 ; i < MAX_ARG_PAGES ; i++) { | |
245 | struct page *page = bprm->page[i]; | |
246 | if (page) { | |
247 | bprm->page[i] = NULL; | |
248 | install_arg_page(mpnt, page, stack_base); | |
249 | } | |
250 | stack_base += PAGE_SIZE; | |
251 | } | |
252 | up_write(¤t->mm->mmap_sem); | |
253 | ||
254 | /* Can't do it in ia64_elf32_init(). Needs to be done before calls to | |
255 | elf32_map() */ | |
256 | current->thread.ppl = ia32_init_pp_list(); | |
257 | ||
258 | return 0; | |
259 | } | |
260 | ||
261 | static void | |
262 | elf32_set_personality (void) | |
263 | { | |
264 | set_personality(PER_LINUX32); | |
265 | current->thread.map_base = IA32_PAGE_OFFSET/3; | |
1da177e4 LT |
266 | } |
267 | ||
268 | static unsigned long | |
269 | elf32_map (struct file *filep, unsigned long addr, struct elf_phdr *eppnt, int prot, int type) | |
270 | { | |
271 | unsigned long pgoff = (eppnt->p_vaddr) & ~IA32_PAGE_MASK; | |
272 | ||
273 | return ia32_do_mmap(filep, (addr & IA32_PAGE_MASK), eppnt->p_filesz + pgoff, prot, type, | |
274 | eppnt->p_offset - pgoff); | |
275 | } | |
276 | ||
277 | #define cpu_uses_ia32el() (local_cpu_data->family > 0x1f) | |
278 | ||
279 | static int __init check_elf32_binfmt(void) | |
280 | { | |
281 | if (cpu_uses_ia32el()) { | |
282 | printk("Please use IA-32 EL for executing IA-32 binaries\n"); | |
283 | return unregister_binfmt(&elf_format); | |
284 | } | |
285 | return 0; | |
286 | } | |
287 | ||
288 | module_init(check_elf32_binfmt) |