Root/fs/binfmt_elf_fdpic.c

1/* binfmt_elf_fdpic.c: FDPIC ELF binary format
2 *
3 * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 * Derived from binfmt_elf.c
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 */
12
13#include <linux/module.h>
14
15#include <linux/fs.h>
16#include <linux/stat.h>
17#include <linux/sched.h>
18#include <linux/mm.h>
19#include <linux/mman.h>
20#include <linux/errno.h>
21#include <linux/signal.h>
22#include <linux/binfmts.h>
23#include <linux/string.h>
24#include <linux/file.h>
25#include <linux/fcntl.h>
26#include <linux/slab.h>
27#include <linux/pagemap.h>
28#include <linux/security.h>
29#include <linux/highmem.h>
30#include <linux/highuid.h>
31#include <linux/personality.h>
32#include <linux/ptrace.h>
33#include <linux/init.h>
34#include <linux/elf.h>
35#include <linux/elf-fdpic.h>
36#include <linux/elfcore.h>
37
38#include <asm/uaccess.h>
39#include <asm/param.h>
40#include <asm/pgalloc.h>
41
42typedef char *elf_caddr_t;
43
44#if 0
45#define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
46#else
47#define kdebug(fmt, ...) do {} while(0)
48#endif
49
50#if 0
51#define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
52#else
53#define kdcore(fmt, ...) do {} while(0)
54#endif
55
56MODULE_LICENSE("GPL");
57
58static int load_elf_fdpic_binary(struct linux_binprm *, struct pt_regs *);
59static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
60static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
61                  struct mm_struct *, const char *);
62
63static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
64                   struct elf_fdpic_params *,
65                   struct elf_fdpic_params *);
66
67#ifndef CONFIG_MMU
68static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,
69                        unsigned long *);
70static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
71                           struct file *,
72                           struct mm_struct *);
73#endif
74
75static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
76                         struct file *, struct mm_struct *);
77
78#if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
79static int elf_fdpic_core_dump(long, struct pt_regs *, struct file *, unsigned long limit);
80#endif
81
82static struct linux_binfmt elf_fdpic_format = {
83    .module = THIS_MODULE,
84    .load_binary = load_elf_fdpic_binary,
85#if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
86    .core_dump = elf_fdpic_core_dump,
87#endif
88    .min_coredump = ELF_EXEC_PAGESIZE,
89};
90
91static int __init init_elf_fdpic_binfmt(void)
92{
93    return register_binfmt(&elf_fdpic_format);
94}
95
96static void __exit exit_elf_fdpic_binfmt(void)
97{
98    unregister_binfmt(&elf_fdpic_format);
99}
100
101core_initcall(init_elf_fdpic_binfmt);
102module_exit(exit_elf_fdpic_binfmt);
103
104static int is_elf_fdpic(struct elfhdr *hdr, struct file *file)
105{
106    if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
107        return 0;
108    if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
109        return 0;
110    if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr))
111        return 0;
112    if (!file->f_op || !file->f_op->mmap)
113        return 0;
114    return 1;
115}
116
117/*****************************************************************************/
118/*
119 * read the program headers table into memory
120 */
121static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
122                 struct file *file)
123{
124    struct elf32_phdr *phdr;
125    unsigned long size;
126    int retval, loop;
127
128    if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
129        return -ENOMEM;
130    if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
131        return -ENOMEM;
132
133    size = params->hdr.e_phnum * sizeof(struct elf_phdr);
134    params->phdrs = kmalloc(size, GFP_KERNEL);
135    if (!params->phdrs)
136        return -ENOMEM;
137
138    retval = kernel_read(file, params->hdr.e_phoff,
139                 (char *) params->phdrs, size);
140    if (unlikely(retval != size))
141        return retval < 0 ? retval : -ENOEXEC;
142
143    /* determine stack size for this binary */
144    phdr = params->phdrs;
145    for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
146        if (phdr->p_type != PT_GNU_STACK)
147            continue;
148
149        if (phdr->p_flags & PF_X)
150            params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
151        else
152            params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
153
154        params->stack_size = phdr->p_memsz;
155        break;
156    }
157
158    return 0;
159}
160
161/*****************************************************************************/
162/*
163 * load an fdpic binary into various bits of memory
164 */
165static int load_elf_fdpic_binary(struct linux_binprm *bprm,
166                 struct pt_regs *regs)
167{
168    struct elf_fdpic_params exec_params, interp_params;
169    struct elf_phdr *phdr;
170    unsigned long stack_size, entryaddr;
171#ifdef ELF_FDPIC_PLAT_INIT
172    unsigned long dynaddr;
173#endif
174    struct file *interpreter = NULL; /* to shut gcc up */
175    char *interpreter_name = NULL;
176    int executable_stack;
177    int retval, i;
178
179    kdebug("____ LOAD %d ____", current->pid);
180
181    memset(&exec_params, 0, sizeof(exec_params));
182    memset(&interp_params, 0, sizeof(interp_params));
183
184    exec_params.hdr = *(struct elfhdr *) bprm->buf;
185    exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
186
187    /* check that this is a binary we know how to deal with */
188    retval = -ENOEXEC;
189    if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
190        goto error;
191
192    /* read the program header table */
193    retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
194    if (retval < 0)
195        goto error;
196
197    /* scan for a program header that specifies an interpreter */
198    phdr = exec_params.phdrs;
199
200    for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
201        switch (phdr->p_type) {
202        case PT_INTERP:
203            retval = -ENOMEM;
204            if (phdr->p_filesz > PATH_MAX)
205                goto error;
206            retval = -ENOENT;
207            if (phdr->p_filesz < 2)
208                goto error;
209
210            /* read the name of the interpreter into memory */
211            interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
212            if (!interpreter_name)
213                goto error;
214
215            retval = kernel_read(bprm->file,
216                         phdr->p_offset,
217                         interpreter_name,
218                         phdr->p_filesz);
219            if (unlikely(retval != phdr->p_filesz)) {
220                if (retval >= 0)
221                    retval = -ENOEXEC;
222                goto error;
223            }
224
225            retval = -ENOENT;
226            if (interpreter_name[phdr->p_filesz - 1] != '\0')
227                goto error;
228
229            kdebug("Using ELF interpreter %s", interpreter_name);
230
231            /* replace the program with the interpreter */
232            interpreter = open_exec(interpreter_name);
233            retval = PTR_ERR(interpreter);
234            if (IS_ERR(interpreter)) {
235                interpreter = NULL;
236                goto error;
237            }
238
239            /*
240             * If the binary is not readable then enforce
241             * mm->dumpable = 0 regardless of the interpreter's
242             * permissions.
243             */
244            if (file_permission(interpreter, MAY_READ) < 0)
245                bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
246
247            retval = kernel_read(interpreter, 0, bprm->buf,
248                         BINPRM_BUF_SIZE);
249            if (unlikely(retval != BINPRM_BUF_SIZE)) {
250                if (retval >= 0)
251                    retval = -ENOEXEC;
252                goto error;
253            }
254
255            interp_params.hdr = *((struct elfhdr *) bprm->buf);
256            break;
257
258        case PT_LOAD:
259#ifdef CONFIG_MMU
260            if (exec_params.load_addr == 0)
261                exec_params.load_addr = phdr->p_vaddr;
262#endif
263            break;
264        }
265
266    }
267
268    if (elf_check_const_displacement(&exec_params.hdr))
269        exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
270
271    /* perform insanity checks on the interpreter */
272    if (interpreter_name) {
273        retval = -ELIBBAD;
274        if (!is_elf_fdpic(&interp_params.hdr, interpreter))
275            goto error;
276
277        interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
278
279        /* read the interpreter's program header table */
280        retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
281        if (retval < 0)
282            goto error;
283    }
284
285    stack_size = exec_params.stack_size;
286    if (stack_size < interp_params.stack_size)
287        stack_size = interp_params.stack_size;
288
289    if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
290        executable_stack = EXSTACK_ENABLE_X;
291    else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
292        executable_stack = EXSTACK_DISABLE_X;
293    else if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
294        executable_stack = EXSTACK_ENABLE_X;
295    else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
296        executable_stack = EXSTACK_DISABLE_X;
297    else
298        executable_stack = EXSTACK_DEFAULT;
299
300    retval = -ENOEXEC;
301    if (stack_size == 0)
302        goto error;
303
304    if (elf_check_const_displacement(&interp_params.hdr))
305        interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
306
307    /* flush all traces of the currently running executable */
308    retval = flush_old_exec(bprm);
309    if (retval)
310        goto error;
311
312    /* there's now no turning back... the old userspace image is dead,
313     * defunct, deceased, etc. after this point we have to exit via
314     * error_kill */
315    set_personality(PER_LINUX_FDPIC);
316    set_binfmt(&elf_fdpic_format);
317
318    current->mm->start_code = 0;
319    current->mm->end_code = 0;
320    current->mm->start_stack = 0;
321    current->mm->start_data = 0;
322    current->mm->end_data = 0;
323    current->mm->context.exec_fdpic_loadmap = 0;
324    current->mm->context.interp_fdpic_loadmap = 0;
325
326    current->flags &= ~PF_FORKNOEXEC;
327
328#ifdef CONFIG_MMU
329    elf_fdpic_arch_lay_out_mm(&exec_params,
330                  &interp_params,
331                  &current->mm->start_stack,
332                  &current->mm->start_brk);
333
334    retval = setup_arg_pages(bprm, current->mm->start_stack,
335                 executable_stack);
336    if (retval < 0) {
337        send_sig(SIGKILL, current, 0);
338        goto error_kill;
339    }
340#endif
341
342    /* load the executable and interpreter into memory */
343    retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
344                    "executable");
345    if (retval < 0)
346        goto error_kill;
347
348    if (interpreter_name) {
349        retval = elf_fdpic_map_file(&interp_params, interpreter,
350                        current->mm, "interpreter");
351        if (retval < 0) {
352            printk(KERN_ERR "Unable to load interpreter\n");
353            goto error_kill;
354        }
355
356        allow_write_access(interpreter);
357        fput(interpreter);
358        interpreter = NULL;
359    }
360
361#ifdef CONFIG_MMU
362    if (!current->mm->start_brk)
363        current->mm->start_brk = current->mm->end_data;
364
365    current->mm->brk = current->mm->start_brk =
366        PAGE_ALIGN(current->mm->start_brk);
367
368#else
369    /* create a stack and brk area big enough for everyone
370     * - the brk heap starts at the bottom and works up
371     * - the stack starts at the top and works down
372     */
373    stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
374    if (stack_size < PAGE_SIZE * 2)
375        stack_size = PAGE_SIZE * 2;
376
377    down_write(&current->mm->mmap_sem);
378    current->mm->start_brk = do_mmap(NULL, 0, stack_size,
379                     PROT_READ | PROT_WRITE | PROT_EXEC,
380                     MAP_PRIVATE | MAP_ANONYMOUS | MAP_GROWSDOWN,
381                     0);
382
383    if (IS_ERR_VALUE(current->mm->start_brk)) {
384        up_write(&current->mm->mmap_sem);
385        retval = current->mm->start_brk;
386        current->mm->start_brk = 0;
387        goto error_kill;
388    }
389
390    up_write(&current->mm->mmap_sem);
391
392    current->mm->brk = current->mm->start_brk;
393    current->mm->context.end_brk = current->mm->start_brk;
394    current->mm->context.end_brk +=
395        (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
396    current->mm->start_stack = current->mm->start_brk + stack_size;
397#endif
398
399    install_exec_creds(bprm);
400    current->flags &= ~PF_FORKNOEXEC;
401    if (create_elf_fdpic_tables(bprm, current->mm,
402                    &exec_params, &interp_params) < 0)
403        goto error_kill;
404
405    kdebug("- start_code %lx", current->mm->start_code);
406    kdebug("- end_code %lx", current->mm->end_code);
407    kdebug("- start_data %lx", current->mm->start_data);
408    kdebug("- end_data %lx", current->mm->end_data);
409    kdebug("- start_brk %lx", current->mm->start_brk);
410    kdebug("- brk %lx", current->mm->brk);
411    kdebug("- start_stack %lx", current->mm->start_stack);
412
413#ifdef ELF_FDPIC_PLAT_INIT
414    /*
415     * The ABI may specify that certain registers be set up in special
416     * ways (on i386 %edx is the address of a DT_FINI function, for
417     * example. This macro performs whatever initialization to
418     * the regs structure is required.
419     */
420    dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
421    ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
422                dynaddr);
423#endif
424
425    /* everything is now ready... get the userspace context ready to roll */
426    entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
427    start_thread(regs, entryaddr, current->mm->start_stack);
428
429    retval = 0;
430
431error:
432    if (interpreter) {
433        allow_write_access(interpreter);
434        fput(interpreter);
435    }
436    kfree(interpreter_name);
437    kfree(exec_params.phdrs);
438    kfree(exec_params.loadmap);
439    kfree(interp_params.phdrs);
440    kfree(interp_params.loadmap);
441    return retval;
442
443    /* unrecoverable error - kill the process */
444error_kill:
445    send_sig(SIGSEGV, current, 0);
446    goto error;
447
448}
449
450/*****************************************************************************/
451
452#ifndef ELF_BASE_PLATFORM
453/*
454 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
455 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
456 * will be copied to the user stack in the same manner as AT_PLATFORM.
457 */
458#define ELF_BASE_PLATFORM NULL
459#endif
460
461/*
462 * present useful information to the program by shovelling it onto the new
463 * process's stack
464 */
465static int create_elf_fdpic_tables(struct linux_binprm *bprm,
466                   struct mm_struct *mm,
467                   struct elf_fdpic_params *exec_params,
468                   struct elf_fdpic_params *interp_params)
469{
470    const struct cred *cred = current_cred();
471    unsigned long sp, csp, nitems;
472    elf_caddr_t __user *argv, *envp;
473    size_t platform_len = 0, len;
474    char *k_platform, *k_base_platform;
475    char __user *u_platform, *u_base_platform, *p;
476    long hwcap;
477    int loop;
478    int nr; /* reset for each csp adjustment */
479
480#ifdef CONFIG_MMU
481    /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
482     * by the processes running on the same package. One thing we can do is
483     * to shuffle the initial stack for them, so we give the architecture
484     * an opportunity to do so here.
485     */
486    sp = arch_align_stack(bprm->p);
487#else
488    sp = mm->start_stack;
489
490    /* stack the program arguments and environment */
491    if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
492        return -EFAULT;
493#endif
494
495    hwcap = ELF_HWCAP;
496
497    /*
498     * If this architecture has a platform capability string, copy it
499     * to userspace. In some cases (Sparc), this info is impossible
500     * for userspace to get any other way, in others (i386) it is
501     * merely difficult.
502     */
503    k_platform = ELF_PLATFORM;
504    u_platform = NULL;
505
506    if (k_platform) {
507        platform_len = strlen(k_platform) + 1;
508        sp -= platform_len;
509        u_platform = (char __user *) sp;
510        if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
511            return -EFAULT;
512    }
513
514    /*
515     * If this architecture has a "base" platform capability
516     * string, copy it to userspace.
517     */
518    k_base_platform = ELF_BASE_PLATFORM;
519    u_base_platform = NULL;
520
521    if (k_base_platform) {
522        platform_len = strlen(k_base_platform) + 1;
523        sp -= platform_len;
524        u_base_platform = (char __user *) sp;
525        if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
526            return -EFAULT;
527    }
528
529    sp &= ~7UL;
530
531    /* stack the load map(s) */
532    len = sizeof(struct elf32_fdpic_loadmap);
533    len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
534    sp = (sp - len) & ~7UL;
535    exec_params->map_addr = sp;
536
537    if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
538        return -EFAULT;
539
540    current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
541
542    if (interp_params->loadmap) {
543        len = sizeof(struct elf32_fdpic_loadmap);
544        len += sizeof(struct elf32_fdpic_loadseg) *
545            interp_params->loadmap->nsegs;
546        sp = (sp - len) & ~7UL;
547        interp_params->map_addr = sp;
548
549        if (copy_to_user((void __user *) sp, interp_params->loadmap,
550                 len) != 0)
551            return -EFAULT;
552
553        current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
554    }
555
556    /* force 16 byte _final_ alignment here for generality */
557#define DLINFO_ITEMS 15
558
559    nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
560        (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
561
562    if (bprm->interp_flags & BINPRM_FLAGS_EXECFD)
563        nitems++;
564
565    csp = sp;
566    sp -= nitems * 2 * sizeof(unsigned long);
567    sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */
568    sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */
569    sp -= 1 * sizeof(unsigned long); /* argc */
570
571    csp -= sp & 15UL;
572    sp -= sp & 15UL;
573
574    /* put the ELF interpreter info on the stack */
575#define NEW_AUX_ENT(id, val) \
576    do { \
577        struct { unsigned long _id, _val; } __user *ent; \
578                                    \
579        ent = (void __user *) csp; \
580        __put_user((id), &ent[nr]._id); \
581        __put_user((val), &ent[nr]._val); \
582        nr++; \
583    } while (0)
584
585    nr = 0;
586    csp -= 2 * sizeof(unsigned long);
587    NEW_AUX_ENT(AT_NULL, 0);
588    if (k_platform) {
589        nr = 0;
590        csp -= 2 * sizeof(unsigned long);
591        NEW_AUX_ENT(AT_PLATFORM,
592                (elf_addr_t) (unsigned long) u_platform);
593    }
594
595    if (k_base_platform) {
596        nr = 0;
597        csp -= 2 * sizeof(unsigned long);
598        NEW_AUX_ENT(AT_BASE_PLATFORM,
599                (elf_addr_t) (unsigned long) u_base_platform);
600    }
601
602    if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
603        nr = 0;
604        csp -= 2 * sizeof(unsigned long);
605        NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
606    }
607
608    nr = 0;
609    csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
610    NEW_AUX_ENT(AT_HWCAP, hwcap);
611    NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE);
612    NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
613    NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr);
614    NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
615    NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum);
616    NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr);
617    NEW_AUX_ENT(AT_FLAGS, 0);
618    NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr);
619    NEW_AUX_ENT(AT_UID, (elf_addr_t) cred->uid);
620    NEW_AUX_ENT(AT_EUID, (elf_addr_t) cred->euid);
621    NEW_AUX_ENT(AT_GID, (elf_addr_t) cred->gid);
622    NEW_AUX_ENT(AT_EGID, (elf_addr_t) cred->egid);
623    NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
624    NEW_AUX_ENT(AT_EXECFN, bprm->exec);
625
626#ifdef ARCH_DLINFO
627    nr = 0;
628    csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
629
630    /* ARCH_DLINFO must come last so platform specific code can enforce
631     * special alignment requirements on the AUXV if necessary (eg. PPC).
632     */
633    ARCH_DLINFO;
634#endif
635#undef NEW_AUX_ENT
636
637    /* allocate room for argv[] and envv[] */
638    csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
639    envp = (elf_caddr_t __user *) csp;
640    csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
641    argv = (elf_caddr_t __user *) csp;
642
643    /* stack argc */
644    csp -= sizeof(unsigned long);
645    __put_user(bprm->argc, (unsigned long __user *) csp);
646
647    BUG_ON(csp != sp);
648
649    /* fill in the argv[] array */
650#ifdef CONFIG_MMU
651    current->mm->arg_start = bprm->p;
652#else
653    current->mm->arg_start = current->mm->start_stack -
654        (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
655#endif
656
657    p = (char __user *) current->mm->arg_start;
658    for (loop = bprm->argc; loop > 0; loop--) {
659        __put_user((elf_caddr_t) p, argv++);
660        len = strnlen_user(p, MAX_ARG_STRLEN);
661        if (!len || len > MAX_ARG_STRLEN)
662            return -EINVAL;
663        p += len;
664    }
665    __put_user(NULL, argv);
666    current->mm->arg_end = (unsigned long) p;
667
668    /* fill in the envv[] array */
669    current->mm->env_start = (unsigned long) p;
670    for (loop = bprm->envc; loop > 0; loop--) {
671        __put_user((elf_caddr_t)(unsigned long) p, envp++);
672        len = strnlen_user(p, MAX_ARG_STRLEN);
673        if (!len || len > MAX_ARG_STRLEN)
674            return -EINVAL;
675        p += len;
676    }
677    __put_user(NULL, envp);
678    current->mm->env_end = (unsigned long) p;
679
680    mm->start_stack = (unsigned long) sp;
681    return 0;
682}
683
684/*****************************************************************************/
685/*
686 * transfer the program arguments and environment from the holding pages onto
687 * the stack
688 */
689#ifndef CONFIG_MMU
690static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
691                        unsigned long *_sp)
692{
693    unsigned long index, stop, sp;
694    char *src;
695    int ret = 0;
696
697    stop = bprm->p >> PAGE_SHIFT;
698    sp = *_sp;
699
700    for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
701        src = kmap(bprm->page[index]);
702        sp -= PAGE_SIZE;
703        if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
704            ret = -EFAULT;
705        kunmap(bprm->page[index]);
706        if (ret < 0)
707            goto out;
708    }
709
710    *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
711
712out:
713    return ret;
714}
715#endif
716
717/*****************************************************************************/
718/*
719 * load the appropriate binary image (executable or interpreter) into memory
720 * - we assume no MMU is available
721 * - if no other PIC bits are set in params->hdr->e_flags
722 * - we assume that the LOADable segments in the binary are independently relocatable
723 * - we assume R/O executable segments are shareable
724 * - else
725 * - we assume the loadable parts of the image to require fixed displacement
726 * - the image is not shareable
727 */
728static int elf_fdpic_map_file(struct elf_fdpic_params *params,
729                  struct file *file,
730                  struct mm_struct *mm,
731                  const char *what)
732{
733    struct elf32_fdpic_loadmap *loadmap;
734#ifdef CONFIG_MMU
735    struct elf32_fdpic_loadseg *mseg;
736#endif
737    struct elf32_fdpic_loadseg *seg;
738    struct elf32_phdr *phdr;
739    unsigned long load_addr, stop;
740    unsigned nloads, tmp;
741    size_t size;
742    int loop, ret;
743
744    /* allocate a load map table */
745    nloads = 0;
746    for (loop = 0; loop < params->hdr.e_phnum; loop++)
747        if (params->phdrs[loop].p_type == PT_LOAD)
748            nloads++;
749
750    if (nloads == 0)
751        return -ELIBBAD;
752
753    size = sizeof(*loadmap) + nloads * sizeof(*seg);
754    loadmap = kzalloc(size, GFP_KERNEL);
755    if (!loadmap)
756        return -ENOMEM;
757
758    params->loadmap = loadmap;
759
760    loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
761    loadmap->nsegs = nloads;
762
763    load_addr = params->load_addr;
764    seg = loadmap->segs;
765
766    /* map the requested LOADs into the memory space */
767    switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
768    case ELF_FDPIC_FLAG_CONSTDISP:
769    case ELF_FDPIC_FLAG_CONTIGUOUS:
770#ifndef CONFIG_MMU
771        ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
772        if (ret < 0)
773            return ret;
774        break;
775#endif
776    default:
777        ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
778        if (ret < 0)
779            return ret;
780        break;
781    }
782
783    /* map the entry point */
784    if (params->hdr.e_entry) {
785        seg = loadmap->segs;
786        for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
787            if (params->hdr.e_entry >= seg->p_vaddr &&
788                params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
789                params->entry_addr =
790                    (params->hdr.e_entry - seg->p_vaddr) +
791                    seg->addr;
792                break;
793            }
794        }
795    }
796
797    /* determine where the program header table has wound up if mapped */
798    stop = params->hdr.e_phoff;
799    stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
800    phdr = params->phdrs;
801
802    for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
803        if (phdr->p_type != PT_LOAD)
804            continue;
805
806        if (phdr->p_offset > params->hdr.e_phoff ||
807            phdr->p_offset + phdr->p_filesz < stop)
808            continue;
809
810        seg = loadmap->segs;
811        for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
812            if (phdr->p_vaddr >= seg->p_vaddr &&
813                phdr->p_vaddr + phdr->p_filesz <=
814                seg->p_vaddr + seg->p_memsz) {
815                params->ph_addr =
816                    (phdr->p_vaddr - seg->p_vaddr) +
817                    seg->addr +
818                    params->hdr.e_phoff - phdr->p_offset;
819                break;
820            }
821        }
822        break;
823    }
824
825    /* determine where the dynamic section has wound up if there is one */
826    phdr = params->phdrs;
827    for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
828        if (phdr->p_type != PT_DYNAMIC)
829            continue;
830
831        seg = loadmap->segs;
832        for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
833            if (phdr->p_vaddr >= seg->p_vaddr &&
834                phdr->p_vaddr + phdr->p_memsz <=
835                seg->p_vaddr + seg->p_memsz) {
836                params->dynamic_addr =
837                    (phdr->p_vaddr - seg->p_vaddr) +
838                    seg->addr;
839
840                /* check the dynamic section contains at least
841                 * one item, and that the last item is a NULL
842                 * entry */
843                if (phdr->p_memsz == 0 ||
844                    phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
845                    goto dynamic_error;
846
847                tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
848                if (((Elf32_Dyn *)
849                     params->dynamic_addr)[tmp - 1].d_tag != 0)
850                    goto dynamic_error;
851                break;
852            }
853        }
854        break;
855    }
856
857    /* now elide adjacent segments in the load map on MMU linux
858     * - on uClinux the holes between may actually be filled with system
859     * stuff or stuff from other processes
860     */
861#ifdef CONFIG_MMU
862    nloads = loadmap->nsegs;
863    mseg = loadmap->segs;
864    seg = mseg + 1;
865    for (loop = 1; loop < nloads; loop++) {
866        /* see if we have a candidate for merging */
867        if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
868            load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
869            if (load_addr == (seg->addr & PAGE_MASK)) {
870                mseg->p_memsz +=
871                    load_addr -
872                    (mseg->addr + mseg->p_memsz);
873                mseg->p_memsz += seg->addr & ~PAGE_MASK;
874                mseg->p_memsz += seg->p_memsz;
875                loadmap->nsegs--;
876                continue;
877            }
878        }
879
880        mseg++;
881        if (mseg != seg)
882            *mseg = *seg;
883    }
884#endif
885
886    kdebug("Mapped Object [%s]:", what);
887    kdebug("- elfhdr : %lx", params->elfhdr_addr);
888    kdebug("- entry : %lx", params->entry_addr);
889    kdebug("- PHDR[] : %lx", params->ph_addr);
890    kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
891    seg = loadmap->segs;
892    for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
893        kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
894               loop,
895               seg->addr, seg->addr + seg->p_memsz - 1,
896               seg->p_vaddr, seg->p_memsz);
897
898    return 0;
899
900dynamic_error:
901    printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
902           what, file->f_path.dentry->d_inode->i_ino);
903    return -ELIBBAD;
904}
905
906/*****************************************************************************/
907/*
908 * map a file with constant displacement under uClinux
909 */
910#ifndef CONFIG_MMU
911static int elf_fdpic_map_file_constdisp_on_uclinux(
912    struct elf_fdpic_params *params,
913    struct file *file,
914    struct mm_struct *mm)
915{
916    struct elf32_fdpic_loadseg *seg;
917    struct elf32_phdr *phdr;
918    unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
919    loff_t fpos;
920    int loop, ret;
921
922    load_addr = params->load_addr;
923    seg = params->loadmap->segs;
924
925    /* determine the bounds of the contiguous overall allocation we must
926     * make */
927    phdr = params->phdrs;
928    for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
929        if (params->phdrs[loop].p_type != PT_LOAD)
930            continue;
931
932        if (base > phdr->p_vaddr)
933            base = phdr->p_vaddr;
934        if (top < phdr->p_vaddr + phdr->p_memsz)
935            top = phdr->p_vaddr + phdr->p_memsz;
936    }
937
938    /* allocate one big anon block for everything */
939    mflags = MAP_PRIVATE;
940    if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
941        mflags |= MAP_EXECUTABLE;
942
943    down_write(&mm->mmap_sem);
944    maddr = do_mmap(NULL, load_addr, top - base,
945            PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
946    up_write(&mm->mmap_sem);
947    if (IS_ERR_VALUE(maddr))
948        return (int) maddr;
949
950    if (load_addr != 0)
951        load_addr += PAGE_ALIGN(top - base);
952
953    /* and then load the file segments into it */
954    phdr = params->phdrs;
955    for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
956        if (params->phdrs[loop].p_type != PT_LOAD)
957            continue;
958
959        fpos = phdr->p_offset;
960
961        seg->addr = maddr + (phdr->p_vaddr - base);
962        seg->p_vaddr = phdr->p_vaddr;
963        seg->p_memsz = phdr->p_memsz;
964
965        ret = file->f_op->read(file, (void *) seg->addr,
966                       phdr->p_filesz, &fpos);
967        if (ret < 0)
968            return ret;
969
970        /* map the ELF header address if in this segment */
971        if (phdr->p_offset == 0)
972            params->elfhdr_addr = seg->addr;
973
974        /* clear any space allocated but not loaded */
975        if (phdr->p_filesz < phdr->p_memsz) {
976            ret = clear_user((void *) (seg->addr + phdr->p_filesz),
977                     phdr->p_memsz - phdr->p_filesz);
978            if (ret)
979                return ret;
980        }
981
982        if (mm) {
983            if (phdr->p_flags & PF_X) {
984                if (!mm->start_code) {
985                    mm->start_code = seg->addr;
986                    mm->end_code = seg->addr +
987                        phdr->p_memsz;
988                }
989            } else if (!mm->start_data) {
990                mm->start_data = seg->addr;
991#ifndef CONFIG_MMU
992                mm->end_data = seg->addr + phdr->p_memsz;
993#endif
994            }
995
996#ifdef CONFIG_MMU
997            if (seg->addr + phdr->p_memsz > mm->end_data)
998                mm->end_data = seg->addr + phdr->p_memsz;
999#endif
1000        }
1001
1002        seg++;
1003    }
1004
1005    return 0;
1006}
1007#endif
1008
1009/*****************************************************************************/
1010/*
1011 * map a binary by direct mmap() of the individual PT_LOAD segments
1012 */
1013static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1014                         struct file *file,
1015                         struct mm_struct *mm)
1016{
1017    struct elf32_fdpic_loadseg *seg;
1018    struct elf32_phdr *phdr;
1019    unsigned long load_addr, delta_vaddr;
1020    int loop, dvset, ret;
1021
1022    load_addr = params->load_addr;
1023    delta_vaddr = 0;
1024    dvset = 0;
1025
1026    seg = params->loadmap->segs;
1027
1028    /* deal with each load segment separately */
1029    phdr = params->phdrs;
1030    for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1031        unsigned long maddr, disp, excess, excess1;
1032        int prot = 0, flags;
1033
1034        if (phdr->p_type != PT_LOAD)
1035            continue;
1036
1037        kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1038               (unsigned long) phdr->p_vaddr,
1039               (unsigned long) phdr->p_offset,
1040               (unsigned long) phdr->p_filesz,
1041               (unsigned long) phdr->p_memsz);
1042
1043        /* determine the mapping parameters */
1044        if (phdr->p_flags & PF_R) prot |= PROT_READ;
1045        if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1046        if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1047
1048        flags = MAP_PRIVATE | MAP_DENYWRITE;
1049        if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1050            flags |= MAP_EXECUTABLE;
1051
1052        maddr = 0;
1053
1054        switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1055        case ELF_FDPIC_FLAG_INDEPENDENT:
1056            /* PT_LOADs are independently locatable */
1057            break;
1058
1059        case ELF_FDPIC_FLAG_HONOURVADDR:
1060            /* the specified virtual address must be honoured */
1061            maddr = phdr->p_vaddr;
1062            flags |= MAP_FIXED;
1063            break;
1064
1065        case ELF_FDPIC_FLAG_CONSTDISP:
1066            /* constant displacement
1067             * - can be mapped anywhere, but must be mapped as a
1068             * unit
1069             */
1070            if (!dvset) {
1071                maddr = load_addr;
1072                delta_vaddr = phdr->p_vaddr;
1073                dvset = 1;
1074            } else {
1075                maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1076                flags |= MAP_FIXED;
1077            }
1078            break;
1079
1080        case ELF_FDPIC_FLAG_CONTIGUOUS:
1081            /* contiguity handled later */
1082            break;
1083
1084        default:
1085            BUG();
1086        }
1087
1088        maddr &= PAGE_MASK;
1089
1090        /* create the mapping */
1091        disp = phdr->p_vaddr & ~PAGE_MASK;
1092        down_write(&mm->mmap_sem);
1093        maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1094                phdr->p_offset - disp);
1095        up_write(&mm->mmap_sem);
1096
1097        kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1098               loop, phdr->p_memsz + disp, prot, flags,
1099               phdr->p_offset - disp, maddr);
1100
1101        if (IS_ERR_VALUE(maddr))
1102            return (int) maddr;
1103
1104        if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1105            ELF_FDPIC_FLAG_CONTIGUOUS)
1106            load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1107
1108        seg->addr = maddr + disp;
1109        seg->p_vaddr = phdr->p_vaddr;
1110        seg->p_memsz = phdr->p_memsz;
1111
1112        /* map the ELF header address if in this segment */
1113        if (phdr->p_offset == 0)
1114            params->elfhdr_addr = seg->addr;
1115
1116        /* clear the bit between beginning of mapping and beginning of
1117         * PT_LOAD */
1118        if (prot & PROT_WRITE && disp > 0) {
1119            kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1120            ret = clear_user((void __user *) maddr, disp);
1121            if (ret)
1122                return ret;
1123            maddr += disp;
1124        }
1125
1126        /* clear any space allocated but not loaded
1127         * - on uClinux we can just clear the lot
1128         * - on MMU linux we'll get a SIGBUS beyond the last page
1129         * extant in the file
1130         */
1131        excess = phdr->p_memsz - phdr->p_filesz;
1132        excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1133
1134#ifdef CONFIG_MMU
1135        if (excess > excess1) {
1136            unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1137            unsigned long xmaddr;
1138
1139            flags |= MAP_FIXED | MAP_ANONYMOUS;
1140            down_write(&mm->mmap_sem);
1141            xmaddr = do_mmap(NULL, xaddr, excess - excess1,
1142                     prot, flags, 0);
1143            up_write(&mm->mmap_sem);
1144
1145            kdebug("mmap[%d] <anon>"
1146                   " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1147                   loop, xaddr, excess - excess1, prot, flags,
1148                   xmaddr);
1149
1150            if (xmaddr != xaddr)
1151                return -ENOMEM;
1152        }
1153
1154        if (prot & PROT_WRITE && excess1 > 0) {
1155            kdebug("clear[%d] ad=%lx sz=%lx",
1156                   loop, maddr + phdr->p_filesz, excess1);
1157            ret = clear_user((void __user *) maddr + phdr->p_filesz,
1158                     excess1);
1159            if (ret)
1160                return ret;
1161        }
1162
1163#else
1164        if (excess > 0) {
1165            kdebug("clear[%d] ad=%lx sz=%lx",
1166                   loop, maddr + phdr->p_filesz, excess);
1167            ret = clear_user((void *) maddr + phdr->p_filesz, excess);
1168            if (ret)
1169                return ret;
1170        }
1171#endif
1172
1173        if (mm) {
1174            if (phdr->p_flags & PF_X) {
1175                if (!mm->start_code) {
1176                    mm->start_code = maddr;
1177                    mm->end_code = maddr + phdr->p_memsz;
1178                }
1179            } else if (!mm->start_data) {
1180                mm->start_data = maddr;
1181                mm->end_data = maddr + phdr->p_memsz;
1182            }
1183        }
1184
1185        seg++;
1186    }
1187
1188    return 0;
1189}
1190
1191/*****************************************************************************/
1192/*
1193 * ELF-FDPIC core dumper
1194 *
1195 * Modelled on fs/exec.c:aout_core_dump()
1196 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1197 *
1198 * Modelled on fs/binfmt_elf.c core dumper
1199 */
1200#if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1201
1202/*
1203 * These are the only things you should do on a core-file: use only these
1204 * functions to write out all the necessary info.
1205 */
1206static int dump_write(struct file *file, const void *addr, int nr)
1207{
1208    return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1209}
1210
1211static int dump_seek(struct file *file, loff_t off)
1212{
1213    if (file->f_op->llseek) {
1214        if (file->f_op->llseek(file, off, SEEK_SET) != off)
1215            return 0;
1216    } else {
1217        file->f_pos = off;
1218    }
1219    return 1;
1220}
1221
1222/*
1223 * Decide whether a segment is worth dumping; default is yes to be
1224 * sure (missing info is worse than too much; etc).
1225 * Personally I'd include everything, and use the coredump limit...
1226 *
1227 * I think we should skip something. But I am not sure how. H.J.
1228 */
1229static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1230{
1231    int dump_ok;
1232
1233    /* Do not dump I/O mapped devices or special mappings */
1234    if (vma->vm_flags & (VM_IO | VM_RESERVED)) {
1235        kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1236        return 0;
1237    }
1238
1239    /* If we may not read the contents, don't allow us to dump
1240     * them either. "dump_write()" can't handle it anyway.
1241     */
1242    if (!(vma->vm_flags & VM_READ)) {
1243        kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1244        return 0;
1245    }
1246
1247    /* By default, dump shared memory if mapped from an anonymous file. */
1248    if (vma->vm_flags & VM_SHARED) {
1249        if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) {
1250            dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1251            kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1252                   vma->vm_flags, dump_ok ? "yes" : "no");
1253            return dump_ok;
1254        }
1255
1256        dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1257        kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1258               vma->vm_flags, dump_ok ? "yes" : "no");
1259        return dump_ok;
1260    }
1261
1262#ifdef CONFIG_MMU
1263    /* By default, if it hasn't been written to, don't write it out */
1264    if (!vma->anon_vma) {
1265        dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1266        kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1267               vma->vm_flags, dump_ok ? "yes" : "no");
1268        return dump_ok;
1269    }
1270#endif
1271
1272    dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1273    kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1274           dump_ok ? "yes" : "no");
1275    return dump_ok;
1276}
1277
1278/* An ELF note in memory */
1279struct memelfnote
1280{
1281    const char *name;
1282    int type;
1283    unsigned int datasz;
1284    void *data;
1285};
1286
1287static int notesize(struct memelfnote *en)
1288{
1289    int sz;
1290
1291    sz = sizeof(struct elf_note);
1292    sz += roundup(strlen(en->name) + 1, 4);
1293    sz += roundup(en->datasz, 4);
1294
1295    return sz;
1296}
1297
1298/* #define DEBUG */
1299
1300#define DUMP_WRITE(addr, nr) \
1301    do { if (!dump_write(file, (addr), (nr))) return 0; } while(0)
1302#define DUMP_SEEK(off) \
1303    do { if (!dump_seek(file, (off))) return 0; } while(0)
1304
1305static int writenote(struct memelfnote *men, struct file *file)
1306{
1307    struct elf_note en;
1308
1309    en.n_namesz = strlen(men->name) + 1;
1310    en.n_descsz = men->datasz;
1311    en.n_type = men->type;
1312
1313    DUMP_WRITE(&en, sizeof(en));
1314    DUMP_WRITE(men->name, en.n_namesz);
1315    /* XXX - cast from long long to long to avoid need for libgcc.a */
1316    DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */
1317    DUMP_WRITE(men->data, men->datasz);
1318    DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */
1319
1320    return 1;
1321}
1322#undef DUMP_WRITE
1323#undef DUMP_SEEK
1324
1325#define DUMP_WRITE(addr, nr) \
1326    if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1327        goto end_coredump;
1328#define DUMP_SEEK(off) \
1329    if (!dump_seek(file, (off))) \
1330        goto end_coredump;
1331
1332static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1333{
1334    memcpy(elf->e_ident, ELFMAG, SELFMAG);
1335    elf->e_ident[EI_CLASS] = ELF_CLASS;
1336    elf->e_ident[EI_DATA] = ELF_DATA;
1337    elf->e_ident[EI_VERSION] = EV_CURRENT;
1338    elf->e_ident[EI_OSABI] = ELF_OSABI;
1339    memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1340
1341    elf->e_type = ET_CORE;
1342    elf->e_machine = ELF_ARCH;
1343    elf->e_version = EV_CURRENT;
1344    elf->e_entry = 0;
1345    elf->e_phoff = sizeof(struct elfhdr);
1346    elf->e_shoff = 0;
1347    elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1348    elf->e_ehsize = sizeof(struct elfhdr);
1349    elf->e_phentsize = sizeof(struct elf_phdr);
1350    elf->e_phnum = segs;
1351    elf->e_shentsize = 0;
1352    elf->e_shnum = 0;
1353    elf->e_shstrndx = 0;
1354    return;
1355}
1356
1357static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1358{
1359    phdr->p_type = PT_NOTE;
1360    phdr->p_offset = offset;
1361    phdr->p_vaddr = 0;
1362    phdr->p_paddr = 0;
1363    phdr->p_filesz = sz;
1364    phdr->p_memsz = 0;
1365    phdr->p_flags = 0;
1366    phdr->p_align = 0;
1367    return;
1368}
1369
1370static inline void fill_note(struct memelfnote *note, const char *name, int type,
1371        unsigned int sz, void *data)
1372{
1373    note->name = name;
1374    note->type = type;
1375    note->datasz = sz;
1376    note->data = data;
1377    return;
1378}
1379
1380/*
1381 * fill up all the fields in prstatus from the given task struct, except
1382 * registers which need to be filled up seperately.
1383 */
1384static void fill_prstatus(struct elf_prstatus *prstatus,
1385              struct task_struct *p, long signr)
1386{
1387    prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1388    prstatus->pr_sigpend = p->pending.signal.sig[0];
1389    prstatus->pr_sighold = p->blocked.sig[0];
1390    rcu_read_lock();
1391    prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1392    rcu_read_unlock();
1393    prstatus->pr_pid = task_pid_vnr(p);
1394    prstatus->pr_pgrp = task_pgrp_vnr(p);
1395    prstatus->pr_sid = task_session_vnr(p);
1396    if (thread_group_leader(p)) {
1397        struct task_cputime cputime;
1398
1399        /*
1400         * This is the record for the group leader. It shows the
1401         * group-wide total, not its individual thread total.
1402         */
1403        thread_group_cputime(p, &cputime);
1404        cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1405        cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1406    } else {
1407        cputime_to_timeval(p->utime, &prstatus->pr_utime);
1408        cputime_to_timeval(p->stime, &prstatus->pr_stime);
1409    }
1410    cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1411    cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1412
1413    prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1414    prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1415}
1416
1417static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1418               struct mm_struct *mm)
1419{
1420    const struct cred *cred;
1421    unsigned int i, len;
1422
1423    /* first copy the parameters from user space */
1424    memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1425
1426    len = mm->arg_end - mm->arg_start;
1427    if (len >= ELF_PRARGSZ)
1428        len = ELF_PRARGSZ - 1;
1429    if (copy_from_user(&psinfo->pr_psargs,
1430                   (const char __user *) mm->arg_start, len))
1431        return -EFAULT;
1432    for (i = 0; i < len; i++)
1433        if (psinfo->pr_psargs[i] == 0)
1434            psinfo->pr_psargs[i] = ' ';
1435    psinfo->pr_psargs[len] = 0;
1436
1437    rcu_read_lock();
1438    psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1439    rcu_read_unlock();
1440    psinfo->pr_pid = task_pid_vnr(p);
1441    psinfo->pr_pgrp = task_pgrp_vnr(p);
1442    psinfo->pr_sid = task_session_vnr(p);
1443
1444    i = p->state ? ffz(~p->state) + 1 : 0;
1445    psinfo->pr_state = i;
1446    psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1447    psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1448    psinfo->pr_nice = task_nice(p);
1449    psinfo->pr_flag = p->flags;
1450    rcu_read_lock();
1451    cred = __task_cred(p);
1452    SET_UID(psinfo->pr_uid, cred->uid);
1453    SET_GID(psinfo->pr_gid, cred->gid);
1454    rcu_read_unlock();
1455    strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1456
1457    return 0;
1458}
1459
1460/* Here is the structure in which status of each thread is captured. */
1461struct elf_thread_status
1462{
1463    struct list_head list;
1464    struct elf_prstatus prstatus; /* NT_PRSTATUS */
1465    elf_fpregset_t fpu; /* NT_PRFPREG */
1466    struct task_struct *thread;
1467#ifdef ELF_CORE_COPY_XFPREGS
1468    elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1469#endif
1470    struct memelfnote notes[3];
1471    int num_notes;
1472};
1473
1474/*
1475 * In order to add the specific thread information for the elf file format,
1476 * we need to keep a linked list of every thread's pr_status and then create
1477 * a single section for them in the final core file.
1478 */
1479static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1480{
1481    struct task_struct *p = t->thread;
1482    int sz = 0;
1483
1484    t->num_notes = 0;
1485
1486    fill_prstatus(&t->prstatus, p, signr);
1487    elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1488
1489    fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1490          &t->prstatus);
1491    t->num_notes++;
1492    sz += notesize(&t->notes[0]);
1493
1494    t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1495    if (t->prstatus.pr_fpvalid) {
1496        fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1497              &t->fpu);
1498        t->num_notes++;
1499        sz += notesize(&t->notes[1]);
1500    }
1501
1502#ifdef ELF_CORE_COPY_XFPREGS
1503    if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1504        fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1505              sizeof(t->xfpu), &t->xfpu);
1506        t->num_notes++;
1507        sz += notesize(&t->notes[2]);
1508    }
1509#endif
1510    return sz;
1511}
1512
1513/*
1514 * dump the segments for an MMU process
1515 */
1516#ifdef CONFIG_MMU
1517static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1518               unsigned long *limit, unsigned long mm_flags)
1519{
1520    struct vm_area_struct *vma;
1521
1522    for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1523        unsigned long addr;
1524
1525        if (!maydump(vma, mm_flags))
1526            continue;
1527
1528        for (addr = vma->vm_start;
1529             addr < vma->vm_end;
1530             addr += PAGE_SIZE
1531             ) {
1532            struct vm_area_struct *vma;
1533            struct page *page;
1534
1535            if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1536                       &page, &vma) <= 0) {
1537                DUMP_SEEK(file->f_pos + PAGE_SIZE);
1538            }
1539            else if (page == ZERO_PAGE(0)) {
1540                page_cache_release(page);
1541                DUMP_SEEK(file->f_pos + PAGE_SIZE);
1542            }
1543            else {
1544                void *kaddr;
1545
1546                flush_cache_page(vma, addr, page_to_pfn(page));
1547                kaddr = kmap(page);
1548                if ((*size += PAGE_SIZE) > *limit ||
1549                    !dump_write(file, kaddr, PAGE_SIZE)
1550                    ) {
1551                    kunmap(page);
1552                    page_cache_release(page);
1553                    return -EIO;
1554                }
1555                kunmap(page);
1556                page_cache_release(page);
1557            }
1558        }
1559    }
1560
1561    return 0;
1562
1563end_coredump:
1564    return -EFBIG;
1565}
1566#endif
1567
1568/*
1569 * dump the segments for a NOMMU process
1570 */
1571#ifndef CONFIG_MMU
1572static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1573               unsigned long *limit, unsigned long mm_flags)
1574{
1575    struct vm_area_struct *vma;
1576
1577    for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1578        if (!maydump(vma, mm_flags))
1579            continue;
1580
1581        if ((*size += PAGE_SIZE) > *limit)
1582            return -EFBIG;
1583
1584        if (!dump_write(file, (void *) vma->vm_start,
1585                vma->vm_end - vma->vm_start))
1586            return -EIO;
1587    }
1588
1589    return 0;
1590}
1591#endif
1592
1593/*
1594 * Actual dumper
1595 *
1596 * This is a two-pass process; first we find the offsets of the bits,
1597 * and then they are actually written out. If we run out of core limit
1598 * we just truncate.
1599 */
1600static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
1601                   struct file *file, unsigned long limit)
1602{
1603#define NUM_NOTES 6
1604    int has_dumped = 0;
1605    mm_segment_t fs;
1606    int segs;
1607    size_t size = 0;
1608    int i;
1609    struct vm_area_struct *vma;
1610    struct elfhdr *elf = NULL;
1611    loff_t offset = 0, dataoff;
1612    int numnote;
1613    struct memelfnote *notes = NULL;
1614    struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1615    struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1616     LIST_HEAD(thread_list);
1617     struct list_head *t;
1618    elf_fpregset_t *fpu = NULL;
1619#ifdef ELF_CORE_COPY_XFPREGS
1620    elf_fpxregset_t *xfpu = NULL;
1621#endif
1622    int thread_status_size = 0;
1623    elf_addr_t *auxv;
1624    unsigned long mm_flags;
1625
1626    /*
1627     * We no longer stop all VM operations.
1628     *
1629     * This is because those proceses that could possibly change map_count
1630     * or the mmap / vma pages are now blocked in do_exit on current
1631     * finishing this core dump.
1632     *
1633     * Only ptrace can touch these memory addresses, but it doesn't change
1634     * the map_count or the pages allocated. So no possibility of crashing
1635     * exists while dumping the mm->vm_next areas to the core file.
1636     */
1637
1638    /* alloc memory for large data structures: too large to be on stack */
1639    elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1640    if (!elf)
1641        goto cleanup;
1642    prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1643    if (!prstatus)
1644        goto cleanup;
1645    psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1646    if (!psinfo)
1647        goto cleanup;
1648    notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1649    if (!notes)
1650        goto cleanup;
1651    fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1652    if (!fpu)
1653        goto cleanup;
1654#ifdef ELF_CORE_COPY_XFPREGS
1655    xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1656    if (!xfpu)
1657        goto cleanup;
1658#endif
1659
1660    if (signr) {
1661        struct core_thread *ct;
1662        struct elf_thread_status *tmp;
1663
1664        for (ct = current->mm->core_state->dumper.next;
1665                        ct; ct = ct->next) {
1666            tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1667            if (!tmp)
1668                goto cleanup;
1669
1670            tmp->thread = ct->task;
1671            list_add(&tmp->list, &thread_list);
1672        }
1673
1674        list_for_each(t, &thread_list) {
1675            struct elf_thread_status *tmp;
1676            int sz;
1677
1678            tmp = list_entry(t, struct elf_thread_status, list);
1679            sz = elf_dump_thread_status(signr, tmp);
1680            thread_status_size += sz;
1681        }
1682    }
1683
1684    /* now collect the dump for the current */
1685    fill_prstatus(prstatus, current, signr);
1686    elf_core_copy_regs(&prstatus->pr_reg, regs);
1687
1688    segs = current->mm->map_count;
1689#ifdef ELF_CORE_EXTRA_PHDRS
1690    segs += ELF_CORE_EXTRA_PHDRS;
1691#endif
1692
1693    /* Set up header */
1694    fill_elf_fdpic_header(elf, segs + 1); /* including notes section */
1695
1696    has_dumped = 1;
1697    current->flags |= PF_DUMPCORE;
1698
1699    /*
1700     * Set up the notes in similar form to SVR4 core dumps made
1701     * with info from their /proc.
1702     */
1703
1704    fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1705    fill_psinfo(psinfo, current->group_leader, current->mm);
1706    fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1707
1708    numnote = 2;
1709
1710    auxv = (elf_addr_t *) current->mm->saved_auxv;
1711
1712    i = 0;
1713    do
1714        i += 2;
1715    while (auxv[i - 2] != AT_NULL);
1716    fill_note(&notes[numnote++], "CORE", NT_AUXV,
1717          i * sizeof(elf_addr_t), auxv);
1718
1719      /* Try to dump the FPU. */
1720    if ((prstatus->pr_fpvalid =
1721         elf_core_copy_task_fpregs(current, regs, fpu)))
1722        fill_note(notes + numnote++,
1723              "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1724#ifdef ELF_CORE_COPY_XFPREGS
1725    if (elf_core_copy_task_xfpregs(current, xfpu))
1726        fill_note(notes + numnote++,
1727              "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1728#endif
1729
1730    fs = get_fs();
1731    set_fs(KERNEL_DS);
1732
1733    DUMP_WRITE(elf, sizeof(*elf));
1734    offset += sizeof(*elf); /* Elf header */
1735    offset += (segs+1) * sizeof(struct elf_phdr); /* Program headers */
1736
1737    /* Write notes phdr entry */
1738    {
1739        struct elf_phdr phdr;
1740        int sz = 0;
1741
1742        for (i = 0; i < numnote; i++)
1743            sz += notesize(notes + i);
1744
1745        sz += thread_status_size;
1746
1747        fill_elf_note_phdr(&phdr, sz, offset);
1748        offset += sz;
1749        DUMP_WRITE(&phdr, sizeof(phdr));
1750    }
1751
1752    /* Page-align dumped data */
1753    dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1754
1755    /*
1756     * We must use the same mm->flags while dumping core to avoid
1757     * inconsistency between the program headers and bodies, otherwise an
1758     * unusable core file can be generated.
1759     */
1760    mm_flags = current->mm->flags;
1761
1762    /* write program headers for segments dump */
1763    for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1764        struct elf_phdr phdr;
1765        size_t sz;
1766
1767        sz = vma->vm_end - vma->vm_start;
1768
1769        phdr.p_type = PT_LOAD;
1770        phdr.p_offset = offset;
1771        phdr.p_vaddr = vma->vm_start;
1772        phdr.p_paddr = 0;
1773        phdr.p_filesz = maydump(vma, mm_flags) ? sz : 0;
1774        phdr.p_memsz = sz;
1775        offset += phdr.p_filesz;
1776        phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1777        if (vma->vm_flags & VM_WRITE)
1778            phdr.p_flags |= PF_W;
1779        if (vma->vm_flags & VM_EXEC)
1780            phdr.p_flags |= PF_X;
1781        phdr.p_align = ELF_EXEC_PAGESIZE;
1782
1783        DUMP_WRITE(&phdr, sizeof(phdr));
1784    }
1785
1786#ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1787    ELF_CORE_WRITE_EXTRA_PHDRS;
1788#endif
1789
1790     /* write out the notes section */
1791    for (i = 0; i < numnote; i++)
1792        if (!writenote(notes + i, file))
1793            goto end_coredump;
1794
1795    /* write out the thread status notes section */
1796    list_for_each(t, &thread_list) {
1797        struct elf_thread_status *tmp =
1798                list_entry(t, struct elf_thread_status, list);
1799
1800        for (i = 0; i < tmp->num_notes; i++)
1801            if (!writenote(&tmp->notes[i], file))
1802                goto end_coredump;
1803    }
1804
1805    DUMP_SEEK(dataoff);
1806
1807    if (elf_fdpic_dump_segments(file, &size, &limit, mm_flags) < 0)
1808        goto end_coredump;
1809
1810#ifdef ELF_CORE_WRITE_EXTRA_DATA
1811    ELF_CORE_WRITE_EXTRA_DATA;
1812#endif
1813
1814    if (file->f_pos != offset) {
1815        /* Sanity check */
1816        printk(KERN_WARNING
1817               "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1818               file->f_pos, offset);
1819    }
1820
1821end_coredump:
1822    set_fs(fs);
1823
1824cleanup:
1825    while (!list_empty(&thread_list)) {
1826        struct list_head *tmp = thread_list.next;
1827        list_del(tmp);
1828        kfree(list_entry(tmp, struct elf_thread_status, list));
1829    }
1830
1831    kfree(elf);
1832    kfree(prstatus);
1833    kfree(psinfo);
1834    kfree(notes);
1835    kfree(fpu);
1836#ifdef ELF_CORE_COPY_XFPREGS
1837    kfree(xfpu);
1838#endif
1839    return has_dumped;
1840#undef NUM_NOTES
1841}
1842
1843#endif /* USE_ELF_CORE_DUMP */
1844

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