2 * Written 2000,2002 by Andi Kleen.
4 * Loosely based on the sparc64 and IA64 32bit emulation loaders.
5 * This tricks binfmt_elf.c into loading 32bit binaries using lots
6 * of ugly preprocessor tricks. Talk about very very poor man's inheritance.
8 #include <linux/types.h>
9 #include <linux/config.h>
10 #include <linux/stddef.h>
11 #include <linux/rwsem.h>
12 #include <linux/sched.h>
13 #include <linux/compat.h>
14 #include <linux/string.h>
15 #include <linux/binfmts.h>
17 #include <linux/security.h>
19 #include <asm/segment.h>
20 #include <asm/ptrace.h>
21 #include <asm/processor.h>
22 #include <asm/user32.h>
23 #include <asm/sigcontext32.h>
24 #include <asm/fpu32.h>
26 #include <asm/uaccess.h>
28 #include <asm/vsyscall32.h>
30 #define ELF_NAME "elf/i386"
33 #define AT_SYSINFO_EHDR 33
35 int sysctl_vsyscall32 = 1;
37 #define ARCH_DLINFO do { \
38 if (sysctl_vsyscall32) { \
39 NEW_AUX_ENT(AT_SYSINFO, (u32)(u64)VSYSCALL32_VSYSCALL); \
40 NEW_AUX_ENT(AT_SYSINFO_EHDR, VSYSCALL32_BASE); \
47 #define IA32_EMULATOR 1
49 #define ELF_ET_DYN_BASE (TASK_UNMAPPED_32 + 0x1000000)
52 #define ELF_ARCH EM_386
55 #define ELF_CLASS ELFCLASS32
57 #define ELF_DATA ELFDATA2LSB
59 #define USE_ELF_CORE_DUMP 1
61 /* Overwrite elfcore.h */
62 #define _LINUX_ELFCORE_H 1
63 typedef unsigned int elf_greg_t;
65 #define ELF_NGREG (sizeof (struct user_regs_struct32) / sizeof(elf_greg_t))
66 typedef elf_greg_t elf_gregset_t[ELF_NGREG];
69 * These macros parameterize elf_core_dump in fs/binfmt_elf.c to write out
70 * extra segments containing the vsyscall DSO contents. Dumping its
71 * contents makes post-mortem fully interpretable later without matching up
72 * the same kernel and hardware config to see what PC values meant.
73 * Dumping its extra ELF program headers includes all the other information
74 * a debugger needs to easily find how the vsyscall DSO was being used.
76 #define ELF_CORE_EXTRA_PHDRS (VSYSCALL32_EHDR->e_phnum)
77 #define ELF_CORE_WRITE_EXTRA_PHDRS \
79 const struct elf32_phdr *const vsyscall_phdrs = \
80 (const struct elf32_phdr *) (VSYSCALL32_BASE \
81 + VSYSCALL32_EHDR->e_phoff); \
84 for (i = 0; i < VSYSCALL32_EHDR->e_phnum; ++i) { \
85 struct elf32_phdr phdr = vsyscall_phdrs[i]; \
86 if (phdr.p_type == PT_LOAD) { \
88 ofs = phdr.p_offset = offset; \
89 phdr.p_memsz = PAGE_ALIGN(phdr.p_memsz); \
90 phdr.p_filesz = phdr.p_memsz; \
91 offset += phdr.p_filesz; \
94 phdr.p_offset += ofs; \
95 phdr.p_paddr = 0; /* match other core phdrs */ \
96 DUMP_WRITE(&phdr, sizeof(phdr)); \
99 #define ELF_CORE_WRITE_EXTRA_DATA \
101 const struct elf32_phdr *const vsyscall_phdrs = \
102 (const struct elf32_phdr *) (VSYSCALL32_BASE \
103 + VSYSCALL32_EHDR->e_phoff); \
105 for (i = 0; i < VSYSCALL32_EHDR->e_phnum; ++i) { \
106 if (vsyscall_phdrs[i].p_type == PT_LOAD) \
107 DUMP_WRITE((void *) (u64) vsyscall_phdrs[i].p_vaddr, \
108 PAGE_ALIGN(vsyscall_phdrs[i].p_memsz)); \
114 int si_signo; /* signal number */
115 int si_code; /* extra code */
116 int si_errno; /* errno */
119 #define jiffies_to_timeval(a,b) do { (b)->tv_usec = 0; (b)->tv_sec = (a)/HZ; }while(0)
123 struct elf_siginfo pr_info; /* Info associated with signal */
124 short pr_cursig; /* Current signal */
125 unsigned int pr_sigpend; /* Set of pending signals */
126 unsigned int pr_sighold; /* Set of held signals */
131 struct compat_timeval pr_utime; /* User time */
132 struct compat_timeval pr_stime; /* System time */
133 struct compat_timeval pr_cutime; /* Cumulative user time */
134 struct compat_timeval pr_cstime; /* Cumulative system time */
135 elf_gregset_t pr_reg; /* GP registers */
136 int pr_fpvalid; /* True if math co-processor being used. */
139 #define ELF_PRARGSZ (80) /* Number of chars for args */
143 char pr_state; /* numeric process state */
144 char pr_sname; /* char for pr_state */
145 char pr_zomb; /* zombie */
146 char pr_nice; /* nice val */
147 unsigned int pr_flag; /* flags */
150 pid_t pr_pid, pr_ppid, pr_pgrp, pr_sid;
152 char pr_fname[16]; /* filename of executable */
153 char pr_psargs[ELF_PRARGSZ]; /* initial part of arg list */
157 #define STR(x) __STR(x)
159 #define _GET_SEG(x) \
160 ({ __u32 seg; asm("movl %%" STR(x) ",%0" : "=r"(seg)); seg; })
162 /* Assumes current==process to be dumped */
163 #define ELF_CORE_COPY_REGS(pr_reg, regs) \
164 pr_reg[0] = regs->rbx; \
165 pr_reg[1] = regs->rcx; \
166 pr_reg[2] = regs->rdx; \
167 pr_reg[3] = regs->rsi; \
168 pr_reg[4] = regs->rdi; \
169 pr_reg[5] = regs->rbp; \
170 pr_reg[6] = regs->rax; \
171 pr_reg[7] = _GET_SEG(ds); \
172 pr_reg[8] = _GET_SEG(es); \
173 pr_reg[9] = _GET_SEG(fs); \
174 pr_reg[10] = _GET_SEG(gs); \
175 pr_reg[11] = regs->orig_rax; \
176 pr_reg[12] = regs->rip; \
177 pr_reg[13] = regs->cs; \
178 pr_reg[14] = regs->eflags; \
179 pr_reg[15] = regs->rsp; \
180 pr_reg[16] = regs->ss;
184 #define __ASM_X86_64_ELF_H 1
185 //#include <asm/ia32.h>
186 #include <linux/elf.h>
188 typedef struct user_i387_ia32_struct elf_fpregset_t;
189 typedef struct user32_fxsr_struct elf_fpxregset_t;
192 static inline void elf_core_copy_regs(elf_gregset_t *elfregs, struct pt_regs *regs)
194 ELF_CORE_COPY_REGS((*elfregs), regs)
197 static inline int elf_core_copy_task_regs(struct task_struct *t, elf_gregset_t* elfregs)
199 struct pt_regs *pp = (struct pt_regs *)(t->thread.rsp0);
201 ELF_CORE_COPY_REGS((*elfregs), pp);
202 /* fix wrong segments */
203 (*elfregs)[7] = t->thread.ds;
204 (*elfregs)[9] = t->thread.fsindex;
205 (*elfregs)[10] = t->thread.gsindex;
206 (*elfregs)[8] = t->thread.es;
211 elf_core_copy_task_fpregs(struct task_struct *tsk, struct pt_regs *regs, elf_fpregset_t *fpu)
213 struct _fpstate_ia32 *fpstate = (void*)fpu;
214 mm_segment_t oldfs = get_fs();
219 regs = (struct pt_regs *)tsk->thread.rsp0;
224 save_i387_ia32(tsk, fpstate, regs, 1);
225 /* Correct for i386 bug. It puts the fop into the upper 16bits of
226 the tag word (like FXSAVE), not into the fcs*/
227 fpstate->cssel |= fpstate->tag & 0xffff0000;
232 #define ELF_CORE_COPY_XFPREGS 1
234 elf_core_copy_task_xfpregs(struct task_struct *t, elf_fpxregset_t *xfpu)
236 struct pt_regs *regs = ((struct pt_regs *)(t->thread.rsp0))-1;
241 memcpy(xfpu, &t->thread.i387.fxsave, sizeof(elf_fpxregset_t));
242 xfpu->fcs = regs->cs;
243 xfpu->fos = t->thread.ds; /* right? */
247 #undef elf_check_arch
248 #define elf_check_arch(x) \
249 ((x)->e_machine == EM_386)
251 #define ELF_EXEC_PAGESIZE PAGE_SIZE
252 #define ELF_HWCAP (boot_cpu_data.x86_capability[0])
253 #define ELF_PLATFORM ("i686")
254 #define SET_PERSONALITY(ex, ibcs2) \
256 unsigned long new_flags = 0; \
257 if ((ex).e_ident[EI_CLASS] == ELFCLASS32) \
258 new_flags = _TIF_IA32; \
259 if ((current_thread_info()->flags & _TIF_IA32) \
261 set_thread_flag(TIF_ABI_PENDING); \
263 clear_thread_flag(TIF_ABI_PENDING); \
266 /* Override some function names */
267 #define elf_format elf32_format
269 #define init_elf_binfmt init_elf32_binfmt
270 #define exit_elf_binfmt exit_elf32_binfmt
272 #define load_elf_binary load_elf32_binary
274 #define ELF_PLAT_INIT(r, load_addr) elf32_init(r)
275 #define setup_arg_pages(bprm, exec_stack) ia32_setup_arg_pages(bprm, exec_stack)
276 int ia32_setup_arg_pages(struct linux_binprm *bprm, int executable_stack);
279 #define start_thread(regs,new_rip,new_rsp) do { \
280 asm volatile("movl %0,%%fs" :: "r" (0)); \
281 asm volatile("movl %0,%%es; movl %0,%%ds": :"r" (__USER32_DS)); \
283 (regs)->rip = (new_rip); \
284 (regs)->rsp = (new_rsp); \
285 (regs)->eflags = 0x200; \
286 (regs)->cs = __USER32_CS; \
287 (regs)->ss = __USER32_DS; \
292 #define elf_map elf32_map
294 #include <linux/module.h>
296 MODULE_DESCRIPTION("Binary format loader for compatibility with IA32 ELF binaries.");
297 MODULE_AUTHOR("Eric Youngdale, Andi Kleen");
299 #undef MODULE_DESCRIPTION
302 #define elf_addr_t __u32
304 static void elf32_init(struct pt_regs *);
306 #include "../../../fs/binfmt_elf.c"
308 static void elf32_init(struct pt_regs *regs)
310 struct task_struct *me = current;
318 regs->r8 = regs->r9 = regs->r10 = regs->r11 = regs->r12 =
319 regs->r13 = regs->r14 = regs->r15 = 0;
322 me->thread.fsindex = 0;
323 me->thread.gsindex = 0;
324 me->thread.ds = __USER_DS;
325 me->thread.es = __USER_DS;
328 int setup_arg_pages(struct linux_binprm *bprm, int executable_stack)
330 unsigned long stack_base;
331 struct vm_area_struct *mpnt;
332 struct mm_struct *mm = current->mm;
335 stack_base = IA32_STACK_TOP - MAX_ARG_PAGES * PAGE_SIZE;
336 mm->arg_start = bprm->p + stack_base;
338 bprm->p += stack_base;
340 bprm->loader += stack_base;
341 bprm->exec += stack_base;
343 mpnt = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
347 if (security_vm_enough_memory((IA32_STACK_TOP - (PAGE_MASK & (unsigned long) bprm->p))>>PAGE_SHIFT)) {
348 kmem_cache_free(vm_area_cachep, mpnt);
352 down_write(&mm->mmap_sem);
355 mpnt->vm_start = PAGE_MASK & (unsigned long) bprm->p;
356 mpnt->vm_end = IA32_STACK_TOP;
357 if (executable_stack == EXSTACK_ENABLE_X)
358 mpnt->vm_flags = vm_stack_flags32 | VM_EXEC;
359 else if (executable_stack == EXSTACK_DISABLE_X)
360 mpnt->vm_flags = vm_stack_flags32 & ~VM_EXEC;
362 mpnt->vm_flags = vm_stack_flags32;
363 mpnt->vm_page_prot = (mpnt->vm_flags & VM_EXEC) ?
364 PAGE_COPY_EXEC : PAGE_COPY;
367 mpnt->vm_file = NULL;
368 INIT_LIST_HEAD(&mpnt->shared);
369 mpnt->vm_private_data = (void *) 0;
370 insert_vm_struct(mm, mpnt);
371 mm->total_vm = (mpnt->vm_end - mpnt->vm_start) >> PAGE_SHIFT;
374 for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
375 struct page *page = bprm->page[i];
377 bprm->page[i] = NULL;
378 put_dirty_page(current,page,stack_base,mpnt->vm_page_prot);
380 stack_base += PAGE_SIZE;
382 up_write(&mm->mmap_sem);
388 elf32_map (struct file *filep, unsigned long addr, struct elf_phdr *eppnt, int prot, int type)
390 unsigned long map_addr;
391 struct task_struct *me = current;
393 if (prot & PROT_READ)
394 prot |= vm_force_exec32;
396 down_write(&me->mm->mmap_sem);
397 map_addr = do_mmap(filep, ELF_PAGESTART(addr),
398 eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr), prot,
400 eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr));
401 up_write(&me->mm->mmap_sem);
406 /* Register vsyscall32 into the ABI table */
407 #include <linux/sysctl.h>
409 static ctl_table abi_table2[] = {
410 { 99, "vsyscall32", &sysctl_vsyscall32, sizeof(int), 0644, NULL,
415 static ctl_table abi_root_table2[] = {
416 { .ctl_name = CTL_ABI, .procname = "abi", .mode = 0555,
417 .child = abi_table2 },
421 static __init int ia32_binfmt_init(void)
423 register_sysctl_table(abi_root_table2, 1);
426 __initcall(ia32_binfmt_init);