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0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /* binfmt_elf_fdpic.c: FDPIC ELF binary format
0003  *
0004  * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved.
0005  * Written by David Howells (dhowells@redhat.com)
0006  * Derived from binfmt_elf.c
0007  */
0008 
0009 #include <linux/module.h>
0010 
0011 #include <linux/fs.h>
0012 #include <linux/stat.h>
0013 #include <linux/sched.h>
0014 #include <linux/sched/coredump.h>
0015 #include <linux/sched/task_stack.h>
0016 #include <linux/sched/cputime.h>
0017 #include <linux/mm.h>
0018 #include <linux/mman.h>
0019 #include <linux/errno.h>
0020 #include <linux/signal.h>
0021 #include <linux/binfmts.h>
0022 #include <linux/string.h>
0023 #include <linux/file.h>
0024 #include <linux/fcntl.h>
0025 #include <linux/slab.h>
0026 #include <linux/pagemap.h>
0027 #include <linux/security.h>
0028 #include <linux/highmem.h>
0029 #include <linux/highuid.h>
0030 #include <linux/personality.h>
0031 #include <linux/ptrace.h>
0032 #include <linux/init.h>
0033 #include <linux/elf.h>
0034 #include <linux/elf-fdpic.h>
0035 #include <linux/elfcore.h>
0036 #include <linux/coredump.h>
0037 #include <linux/dax.h>
0038 #include <linux/regset.h>
0039 
0040 #include <linux/uaccess.h>
0041 #include <asm/param.h>
0042 
0043 typedef char *elf_caddr_t;
0044 
0045 #if 0
0046 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
0047 #else
0048 #define kdebug(fmt, ...) do {} while(0)
0049 #endif
0050 
0051 #if 0
0052 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
0053 #else
0054 #define kdcore(fmt, ...) do {} while(0)
0055 #endif
0056 
0057 MODULE_LICENSE("GPL");
0058 
0059 static int load_elf_fdpic_binary(struct linux_binprm *);
0060 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
0061 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
0062                   struct mm_struct *, const char *);
0063 
0064 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
0065                    struct elf_fdpic_params *,
0066                    struct elf_fdpic_params *);
0067 
0068 #ifndef CONFIG_MMU
0069 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
0070                            struct file *,
0071                            struct mm_struct *);
0072 #endif
0073 
0074 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
0075                          struct file *, struct mm_struct *);
0076 
0077 #ifdef CONFIG_ELF_CORE
0078 static int elf_fdpic_core_dump(struct coredump_params *cprm);
0079 #endif
0080 
0081 static struct linux_binfmt elf_fdpic_format = {
0082     .module     = THIS_MODULE,
0083     .load_binary    = load_elf_fdpic_binary,
0084 #ifdef CONFIG_ELF_CORE
0085     .core_dump  = elf_fdpic_core_dump,
0086     .min_coredump   = ELF_EXEC_PAGESIZE,
0087 #endif
0088 };
0089 
0090 static int __init init_elf_fdpic_binfmt(void)
0091 {
0092     register_binfmt(&elf_fdpic_format);
0093     return 0;
0094 }
0095 
0096 static void __exit exit_elf_fdpic_binfmt(void)
0097 {
0098     unregister_binfmt(&elf_fdpic_format);
0099 }
0100 
0101 core_initcall(init_elf_fdpic_binfmt);
0102 module_exit(exit_elf_fdpic_binfmt);
0103 
0104 static int is_elf(struct elfhdr *hdr, struct file *file)
0105 {
0106     if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
0107         return 0;
0108     if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
0109         return 0;
0110     if (!elf_check_arch(hdr))
0111         return 0;
0112     if (!file->f_op->mmap)
0113         return 0;
0114     return 1;
0115 }
0116 
0117 #ifndef elf_check_fdpic
0118 #define elf_check_fdpic(x) 0
0119 #endif
0120 
0121 #ifndef elf_check_const_displacement
0122 #define elf_check_const_displacement(x) 0
0123 #endif
0124 
0125 static int is_constdisp(struct elfhdr *hdr)
0126 {
0127     if (!elf_check_fdpic(hdr))
0128         return 1;
0129     if (elf_check_const_displacement(hdr))
0130         return 1;
0131     return 0;
0132 }
0133 
0134 /*****************************************************************************/
0135 /*
0136  * read the program headers table into memory
0137  */
0138 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
0139                  struct file *file)
0140 {
0141     struct elf32_phdr *phdr;
0142     unsigned long size;
0143     int retval, loop;
0144     loff_t pos = params->hdr.e_phoff;
0145 
0146     if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
0147         return -ENOMEM;
0148     if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
0149         return -ENOMEM;
0150 
0151     size = params->hdr.e_phnum * sizeof(struct elf_phdr);
0152     params->phdrs = kmalloc(size, GFP_KERNEL);
0153     if (!params->phdrs)
0154         return -ENOMEM;
0155 
0156     retval = kernel_read(file, params->phdrs, size, &pos);
0157     if (unlikely(retval != size))
0158         return retval < 0 ? retval : -ENOEXEC;
0159 
0160     /* determine stack size for this binary */
0161     phdr = params->phdrs;
0162     for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
0163         if (phdr->p_type != PT_GNU_STACK)
0164             continue;
0165 
0166         if (phdr->p_flags & PF_X)
0167             params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
0168         else
0169             params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
0170 
0171         params->stack_size = phdr->p_memsz;
0172         break;
0173     }
0174 
0175     return 0;
0176 }
0177 
0178 /*****************************************************************************/
0179 /*
0180  * load an fdpic binary into various bits of memory
0181  */
0182 static int load_elf_fdpic_binary(struct linux_binprm *bprm)
0183 {
0184     struct elf_fdpic_params exec_params, interp_params;
0185     struct pt_regs *regs = current_pt_regs();
0186     struct elf_phdr *phdr;
0187     unsigned long stack_size, entryaddr;
0188 #ifdef ELF_FDPIC_PLAT_INIT
0189     unsigned long dynaddr;
0190 #endif
0191 #ifndef CONFIG_MMU
0192     unsigned long stack_prot;
0193 #endif
0194     struct file *interpreter = NULL; /* to shut gcc up */
0195     char *interpreter_name = NULL;
0196     int executable_stack;
0197     int retval, i;
0198     loff_t pos;
0199 
0200     kdebug("____ LOAD %d ____", current->pid);
0201 
0202     memset(&exec_params, 0, sizeof(exec_params));
0203     memset(&interp_params, 0, sizeof(interp_params));
0204 
0205     exec_params.hdr = *(struct elfhdr *) bprm->buf;
0206     exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
0207 
0208     /* check that this is a binary we know how to deal with */
0209     retval = -ENOEXEC;
0210     if (!is_elf(&exec_params.hdr, bprm->file))
0211         goto error;
0212     if (!elf_check_fdpic(&exec_params.hdr)) {
0213 #ifdef CONFIG_MMU
0214         /* binfmt_elf handles non-fdpic elf except on nommu */
0215         goto error;
0216 #else
0217         /* nommu can only load ET_DYN (PIE) ELF */
0218         if (exec_params.hdr.e_type != ET_DYN)
0219             goto error;
0220 #endif
0221     }
0222 
0223     /* read the program header table */
0224     retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
0225     if (retval < 0)
0226         goto error;
0227 
0228     /* scan for a program header that specifies an interpreter */
0229     phdr = exec_params.phdrs;
0230 
0231     for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
0232         switch (phdr->p_type) {
0233         case PT_INTERP:
0234             retval = -ENOMEM;
0235             if (phdr->p_filesz > PATH_MAX)
0236                 goto error;
0237             retval = -ENOENT;
0238             if (phdr->p_filesz < 2)
0239                 goto error;
0240 
0241             /* read the name of the interpreter into memory */
0242             interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
0243             if (!interpreter_name)
0244                 goto error;
0245 
0246             pos = phdr->p_offset;
0247             retval = kernel_read(bprm->file, interpreter_name,
0248                          phdr->p_filesz, &pos);
0249             if (unlikely(retval != phdr->p_filesz)) {
0250                 if (retval >= 0)
0251                     retval = -ENOEXEC;
0252                 goto error;
0253             }
0254 
0255             retval = -ENOENT;
0256             if (interpreter_name[phdr->p_filesz - 1] != '\0')
0257                 goto error;
0258 
0259             kdebug("Using ELF interpreter %s", interpreter_name);
0260 
0261             /* replace the program with the interpreter */
0262             interpreter = open_exec(interpreter_name);
0263             retval = PTR_ERR(interpreter);
0264             if (IS_ERR(interpreter)) {
0265                 interpreter = NULL;
0266                 goto error;
0267             }
0268 
0269             /*
0270              * If the binary is not readable then enforce
0271              * mm->dumpable = 0 regardless of the interpreter's
0272              * permissions.
0273              */
0274             would_dump(bprm, interpreter);
0275 
0276             pos = 0;
0277             retval = kernel_read(interpreter, bprm->buf,
0278                     BINPRM_BUF_SIZE, &pos);
0279             if (unlikely(retval != BINPRM_BUF_SIZE)) {
0280                 if (retval >= 0)
0281                     retval = -ENOEXEC;
0282                 goto error;
0283             }
0284 
0285             interp_params.hdr = *((struct elfhdr *) bprm->buf);
0286             break;
0287 
0288         case PT_LOAD:
0289 #ifdef CONFIG_MMU
0290             if (exec_params.load_addr == 0)
0291                 exec_params.load_addr = phdr->p_vaddr;
0292 #endif
0293             break;
0294         }
0295 
0296     }
0297 
0298     if (is_constdisp(&exec_params.hdr))
0299         exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
0300 
0301     /* perform insanity checks on the interpreter */
0302     if (interpreter_name) {
0303         retval = -ELIBBAD;
0304         if (!is_elf(&interp_params.hdr, interpreter))
0305             goto error;
0306 
0307         interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
0308 
0309         /* read the interpreter's program header table */
0310         retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
0311         if (retval < 0)
0312             goto error;
0313     }
0314 
0315     stack_size = exec_params.stack_size;
0316     if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
0317         executable_stack = EXSTACK_ENABLE_X;
0318     else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
0319         executable_stack = EXSTACK_DISABLE_X;
0320     else
0321         executable_stack = EXSTACK_DEFAULT;
0322 
0323     if (stack_size == 0) {
0324         stack_size = interp_params.stack_size;
0325         if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
0326             executable_stack = EXSTACK_ENABLE_X;
0327         else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
0328             executable_stack = EXSTACK_DISABLE_X;
0329         else
0330             executable_stack = EXSTACK_DEFAULT;
0331     }
0332 
0333     retval = -ENOEXEC;
0334     if (stack_size == 0)
0335         stack_size = 131072UL; /* same as exec.c's default commit */
0336 
0337     if (is_constdisp(&interp_params.hdr))
0338         interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
0339 
0340     /* flush all traces of the currently running executable */
0341     retval = begin_new_exec(bprm);
0342     if (retval)
0343         goto error;
0344 
0345     /* there's now no turning back... the old userspace image is dead,
0346      * defunct, deceased, etc.
0347      */
0348     if (elf_check_fdpic(&exec_params.hdr))
0349         set_personality(PER_LINUX_FDPIC);
0350     else
0351         set_personality(PER_LINUX);
0352     if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
0353         current->personality |= READ_IMPLIES_EXEC;
0354 
0355     setup_new_exec(bprm);
0356 
0357     set_binfmt(&elf_fdpic_format);
0358 
0359     current->mm->start_code = 0;
0360     current->mm->end_code = 0;
0361     current->mm->start_stack = 0;
0362     current->mm->start_data = 0;
0363     current->mm->end_data = 0;
0364     current->mm->context.exec_fdpic_loadmap = 0;
0365     current->mm->context.interp_fdpic_loadmap = 0;
0366 
0367 #ifdef CONFIG_MMU
0368     elf_fdpic_arch_lay_out_mm(&exec_params,
0369                   &interp_params,
0370                   &current->mm->start_stack,
0371                   &current->mm->start_brk);
0372 
0373     retval = setup_arg_pages(bprm, current->mm->start_stack,
0374                  executable_stack);
0375     if (retval < 0)
0376         goto error;
0377 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
0378     retval = arch_setup_additional_pages(bprm, !!interpreter_name);
0379     if (retval < 0)
0380         goto error;
0381 #endif
0382 #endif
0383 
0384     /* load the executable and interpreter into memory */
0385     retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
0386                     "executable");
0387     if (retval < 0)
0388         goto error;
0389 
0390     if (interpreter_name) {
0391         retval = elf_fdpic_map_file(&interp_params, interpreter,
0392                         current->mm, "interpreter");
0393         if (retval < 0) {
0394             printk(KERN_ERR "Unable to load interpreter\n");
0395             goto error;
0396         }
0397 
0398         allow_write_access(interpreter);
0399         fput(interpreter);
0400         interpreter = NULL;
0401     }
0402 
0403 #ifdef CONFIG_MMU
0404     if (!current->mm->start_brk)
0405         current->mm->start_brk = current->mm->end_data;
0406 
0407     current->mm->brk = current->mm->start_brk =
0408         PAGE_ALIGN(current->mm->start_brk);
0409 
0410 #else
0411     /* create a stack area and zero-size brk area */
0412     stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
0413     if (stack_size < PAGE_SIZE * 2)
0414         stack_size = PAGE_SIZE * 2;
0415 
0416     stack_prot = PROT_READ | PROT_WRITE;
0417     if (executable_stack == EXSTACK_ENABLE_X ||
0418         (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
0419         stack_prot |= PROT_EXEC;
0420 
0421     current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
0422                      MAP_PRIVATE | MAP_ANONYMOUS |
0423                      MAP_UNINITIALIZED | MAP_GROWSDOWN,
0424                      0);
0425 
0426     if (IS_ERR_VALUE(current->mm->start_brk)) {
0427         retval = current->mm->start_brk;
0428         current->mm->start_brk = 0;
0429         goto error;
0430     }
0431 
0432     current->mm->brk = current->mm->start_brk;
0433     current->mm->context.end_brk = current->mm->start_brk;
0434     current->mm->start_stack = current->mm->start_brk + stack_size;
0435 #endif
0436 
0437     if (create_elf_fdpic_tables(bprm, current->mm,
0438                     &exec_params, &interp_params) < 0)
0439         goto error;
0440 
0441     kdebug("- start_code  %lx", current->mm->start_code);
0442     kdebug("- end_code    %lx", current->mm->end_code);
0443     kdebug("- start_data  %lx", current->mm->start_data);
0444     kdebug("- end_data    %lx", current->mm->end_data);
0445     kdebug("- start_brk   %lx", current->mm->start_brk);
0446     kdebug("- brk         %lx", current->mm->brk);
0447     kdebug("- start_stack %lx", current->mm->start_stack);
0448 
0449 #ifdef ELF_FDPIC_PLAT_INIT
0450     /*
0451      * The ABI may specify that certain registers be set up in special
0452      * ways (on i386 %edx is the address of a DT_FINI function, for
0453      * example.  This macro performs whatever initialization to
0454      * the regs structure is required.
0455      */
0456     dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
0457     ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
0458                 dynaddr);
0459 #endif
0460 
0461     finalize_exec(bprm);
0462     /* everything is now ready... get the userspace context ready to roll */
0463     entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
0464     start_thread(regs, entryaddr, current->mm->start_stack);
0465 
0466     retval = 0;
0467 
0468 error:
0469     if (interpreter) {
0470         allow_write_access(interpreter);
0471         fput(interpreter);
0472     }
0473     kfree(interpreter_name);
0474     kfree(exec_params.phdrs);
0475     kfree(exec_params.loadmap);
0476     kfree(interp_params.phdrs);
0477     kfree(interp_params.loadmap);
0478     return retval;
0479 }
0480 
0481 /*****************************************************************************/
0482 
0483 #ifndef ELF_BASE_PLATFORM
0484 /*
0485  * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
0486  * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
0487  * will be copied to the user stack in the same manner as AT_PLATFORM.
0488  */
0489 #define ELF_BASE_PLATFORM NULL
0490 #endif
0491 
0492 /*
0493  * present useful information to the program by shovelling it onto the new
0494  * process's stack
0495  */
0496 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
0497                    struct mm_struct *mm,
0498                    struct elf_fdpic_params *exec_params,
0499                    struct elf_fdpic_params *interp_params)
0500 {
0501     const struct cred *cred = current_cred();
0502     unsigned long sp, csp, nitems;
0503     elf_caddr_t __user *argv, *envp;
0504     size_t platform_len = 0, len;
0505     char *k_platform, *k_base_platform;
0506     char __user *u_platform, *u_base_platform, *p;
0507     int loop;
0508     int nr; /* reset for each csp adjustment */
0509     unsigned long flags = 0;
0510 
0511 #ifdef CONFIG_MMU
0512     /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
0513      * by the processes running on the same package. One thing we can do is
0514      * to shuffle the initial stack for them, so we give the architecture
0515      * an opportunity to do so here.
0516      */
0517     sp = arch_align_stack(bprm->p);
0518 #else
0519     sp = mm->start_stack;
0520 
0521     /* stack the program arguments and environment */
0522     if (transfer_args_to_stack(bprm, &sp) < 0)
0523         return -EFAULT;
0524     sp &= ~15;
0525 #endif
0526 
0527     /*
0528      * If this architecture has a platform capability string, copy it
0529      * to userspace.  In some cases (Sparc), this info is impossible
0530      * for userspace to get any other way, in others (i386) it is
0531      * merely difficult.
0532      */
0533     k_platform = ELF_PLATFORM;
0534     u_platform = NULL;
0535 
0536     if (k_platform) {
0537         platform_len = strlen(k_platform) + 1;
0538         sp -= platform_len;
0539         u_platform = (char __user *) sp;
0540         if (copy_to_user(u_platform, k_platform, platform_len) != 0)
0541             return -EFAULT;
0542     }
0543 
0544     /*
0545      * If this architecture has a "base" platform capability
0546      * string, copy it to userspace.
0547      */
0548     k_base_platform = ELF_BASE_PLATFORM;
0549     u_base_platform = NULL;
0550 
0551     if (k_base_platform) {
0552         platform_len = strlen(k_base_platform) + 1;
0553         sp -= platform_len;
0554         u_base_platform = (char __user *) sp;
0555         if (copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
0556             return -EFAULT;
0557     }
0558 
0559     sp &= ~7UL;
0560 
0561     /* stack the load map(s) */
0562     len = sizeof(struct elf32_fdpic_loadmap);
0563     len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
0564     sp = (sp - len) & ~7UL;
0565     exec_params->map_addr = sp;
0566 
0567     if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
0568         return -EFAULT;
0569 
0570     current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
0571 
0572     if (interp_params->loadmap) {
0573         len = sizeof(struct elf32_fdpic_loadmap);
0574         len += sizeof(struct elf32_fdpic_loadseg) *
0575             interp_params->loadmap->nsegs;
0576         sp = (sp - len) & ~7UL;
0577         interp_params->map_addr = sp;
0578 
0579         if (copy_to_user((void __user *) sp, interp_params->loadmap,
0580                  len) != 0)
0581             return -EFAULT;
0582 
0583         current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
0584     }
0585 
0586     /* force 16 byte _final_ alignment here for generality */
0587 #define DLINFO_ITEMS 15
0588 
0589     nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
0590         (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
0591 
0592     if (bprm->have_execfd)
0593         nitems++;
0594 
0595     csp = sp;
0596     sp -= nitems * 2 * sizeof(unsigned long);
0597     sp -= (bprm->envc + 1) * sizeof(char *);    /* envv[] */
0598     sp -= (bprm->argc + 1) * sizeof(char *);    /* argv[] */
0599     sp -= 1 * sizeof(unsigned long);        /* argc */
0600 
0601     csp -= sp & 15UL;
0602     sp -= sp & 15UL;
0603 
0604     /* put the ELF interpreter info on the stack */
0605 #define NEW_AUX_ENT(id, val)                        \
0606     do {                                \
0607         struct { unsigned long _id, _val; } __user *ent, v; \
0608                                     \
0609         ent = (void __user *) csp;              \
0610         v._id = (id);                       \
0611         v._val = (val);                     \
0612         if (copy_to_user(ent + nr, &v, sizeof(v)))      \
0613             return -EFAULT;                 \
0614         nr++;                           \
0615     } while (0)
0616 
0617     nr = 0;
0618     csp -= 2 * sizeof(unsigned long);
0619     NEW_AUX_ENT(AT_NULL, 0);
0620     if (k_platform) {
0621         nr = 0;
0622         csp -= 2 * sizeof(unsigned long);
0623         NEW_AUX_ENT(AT_PLATFORM,
0624                 (elf_addr_t) (unsigned long) u_platform);
0625     }
0626 
0627     if (k_base_platform) {
0628         nr = 0;
0629         csp -= 2 * sizeof(unsigned long);
0630         NEW_AUX_ENT(AT_BASE_PLATFORM,
0631                 (elf_addr_t) (unsigned long) u_base_platform);
0632     }
0633 
0634     if (bprm->have_execfd) {
0635         nr = 0;
0636         csp -= 2 * sizeof(unsigned long);
0637         NEW_AUX_ENT(AT_EXECFD, bprm->execfd);
0638     }
0639 
0640     nr = 0;
0641     csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
0642     NEW_AUX_ENT(AT_HWCAP,   ELF_HWCAP);
0643 #ifdef ELF_HWCAP2
0644     NEW_AUX_ENT(AT_HWCAP2,  ELF_HWCAP2);
0645 #endif
0646     NEW_AUX_ENT(AT_PAGESZ,  PAGE_SIZE);
0647     NEW_AUX_ENT(AT_CLKTCK,  CLOCKS_PER_SEC);
0648     NEW_AUX_ENT(AT_PHDR,    exec_params->ph_addr);
0649     NEW_AUX_ENT(AT_PHENT,   sizeof(struct elf_phdr));
0650     NEW_AUX_ENT(AT_PHNUM,   exec_params->hdr.e_phnum);
0651     NEW_AUX_ENT(AT_BASE,    interp_params->elfhdr_addr);
0652     if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
0653         flags |= AT_FLAGS_PRESERVE_ARGV0;
0654     NEW_AUX_ENT(AT_FLAGS,   flags);
0655     NEW_AUX_ENT(AT_ENTRY,   exec_params->entry_addr);
0656     NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
0657     NEW_AUX_ENT(AT_EUID,    (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
0658     NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
0659     NEW_AUX_ENT(AT_EGID,    (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
0660     NEW_AUX_ENT(AT_SECURE,  bprm->secureexec);
0661     NEW_AUX_ENT(AT_EXECFN,  bprm->exec);
0662 
0663 #ifdef ARCH_DLINFO
0664     nr = 0;
0665     csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
0666 
0667     /* ARCH_DLINFO must come last so platform specific code can enforce
0668      * special alignment requirements on the AUXV if necessary (eg. PPC).
0669      */
0670     ARCH_DLINFO;
0671 #endif
0672 #undef NEW_AUX_ENT
0673 
0674     /* allocate room for argv[] and envv[] */
0675     csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
0676     envp = (elf_caddr_t __user *) csp;
0677     csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
0678     argv = (elf_caddr_t __user *) csp;
0679 
0680     /* stack argc */
0681     csp -= sizeof(unsigned long);
0682     if (put_user(bprm->argc, (unsigned long __user *) csp))
0683         return -EFAULT;
0684 
0685     BUG_ON(csp != sp);
0686 
0687     /* fill in the argv[] array */
0688 #ifdef CONFIG_MMU
0689     current->mm->arg_start = bprm->p;
0690 #else
0691     current->mm->arg_start = current->mm->start_stack -
0692         (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
0693 #endif
0694 
0695     p = (char __user *) current->mm->arg_start;
0696     for (loop = bprm->argc; loop > 0; loop--) {
0697         if (put_user((elf_caddr_t) p, argv++))
0698             return -EFAULT;
0699         len = strnlen_user(p, MAX_ARG_STRLEN);
0700         if (!len || len > MAX_ARG_STRLEN)
0701             return -EINVAL;
0702         p += len;
0703     }
0704     if (put_user(NULL, argv))
0705         return -EFAULT;
0706     current->mm->arg_end = (unsigned long) p;
0707 
0708     /* fill in the envv[] array */
0709     current->mm->env_start = (unsigned long) p;
0710     for (loop = bprm->envc; loop > 0; loop--) {
0711         if (put_user((elf_caddr_t)(unsigned long) p, envp++))
0712             return -EFAULT;
0713         len = strnlen_user(p, MAX_ARG_STRLEN);
0714         if (!len || len > MAX_ARG_STRLEN)
0715             return -EINVAL;
0716         p += len;
0717     }
0718     if (put_user(NULL, envp))
0719         return -EFAULT;
0720     current->mm->env_end = (unsigned long) p;
0721 
0722     mm->start_stack = (unsigned long) sp;
0723     return 0;
0724 }
0725 
0726 /*****************************************************************************/
0727 /*
0728  * load the appropriate binary image (executable or interpreter) into memory
0729  * - we assume no MMU is available
0730  * - if no other PIC bits are set in params->hdr->e_flags
0731  *   - we assume that the LOADable segments in the binary are independently relocatable
0732  *   - we assume R/O executable segments are shareable
0733  * - else
0734  *   - we assume the loadable parts of the image to require fixed displacement
0735  *   - the image is not shareable
0736  */
0737 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
0738                   struct file *file,
0739                   struct mm_struct *mm,
0740                   const char *what)
0741 {
0742     struct elf32_fdpic_loadmap *loadmap;
0743 #ifdef CONFIG_MMU
0744     struct elf32_fdpic_loadseg *mseg;
0745 #endif
0746     struct elf32_fdpic_loadseg *seg;
0747     struct elf32_phdr *phdr;
0748     unsigned long load_addr, stop;
0749     unsigned nloads, tmp;
0750     size_t size;
0751     int loop, ret;
0752 
0753     /* allocate a load map table */
0754     nloads = 0;
0755     for (loop = 0; loop < params->hdr.e_phnum; loop++)
0756         if (params->phdrs[loop].p_type == PT_LOAD)
0757             nloads++;
0758 
0759     if (nloads == 0)
0760         return -ELIBBAD;
0761 
0762     size = sizeof(*loadmap) + nloads * sizeof(*seg);
0763     loadmap = kzalloc(size, GFP_KERNEL);
0764     if (!loadmap)
0765         return -ENOMEM;
0766 
0767     params->loadmap = loadmap;
0768 
0769     loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
0770     loadmap->nsegs = nloads;
0771 
0772     load_addr = params->load_addr;
0773     seg = loadmap->segs;
0774 
0775     /* map the requested LOADs into the memory space */
0776     switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
0777     case ELF_FDPIC_FLAG_CONSTDISP:
0778     case ELF_FDPIC_FLAG_CONTIGUOUS:
0779 #ifndef CONFIG_MMU
0780         ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
0781         if (ret < 0)
0782             return ret;
0783         break;
0784 #endif
0785     default:
0786         ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
0787         if (ret < 0)
0788             return ret;
0789         break;
0790     }
0791 
0792     /* map the entry point */
0793     if (params->hdr.e_entry) {
0794         seg = loadmap->segs;
0795         for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
0796             if (params->hdr.e_entry >= seg->p_vaddr &&
0797                 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
0798                 params->entry_addr =
0799                     (params->hdr.e_entry - seg->p_vaddr) +
0800                     seg->addr;
0801                 break;
0802             }
0803         }
0804     }
0805 
0806     /* determine where the program header table has wound up if mapped */
0807     stop = params->hdr.e_phoff;
0808     stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
0809     phdr = params->phdrs;
0810 
0811     for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
0812         if (phdr->p_type != PT_LOAD)
0813             continue;
0814 
0815         if (phdr->p_offset > params->hdr.e_phoff ||
0816             phdr->p_offset + phdr->p_filesz < stop)
0817             continue;
0818 
0819         seg = loadmap->segs;
0820         for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
0821             if (phdr->p_vaddr >= seg->p_vaddr &&
0822                 phdr->p_vaddr + phdr->p_filesz <=
0823                 seg->p_vaddr + seg->p_memsz) {
0824                 params->ph_addr =
0825                     (phdr->p_vaddr - seg->p_vaddr) +
0826                     seg->addr +
0827                     params->hdr.e_phoff - phdr->p_offset;
0828                 break;
0829             }
0830         }
0831         break;
0832     }
0833 
0834     /* determine where the dynamic section has wound up if there is one */
0835     phdr = params->phdrs;
0836     for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
0837         if (phdr->p_type != PT_DYNAMIC)
0838             continue;
0839 
0840         seg = loadmap->segs;
0841         for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
0842             if (phdr->p_vaddr >= seg->p_vaddr &&
0843                 phdr->p_vaddr + phdr->p_memsz <=
0844                 seg->p_vaddr + seg->p_memsz) {
0845                 Elf32_Dyn __user *dyn;
0846                 Elf32_Sword d_tag;
0847 
0848                 params->dynamic_addr =
0849                     (phdr->p_vaddr - seg->p_vaddr) +
0850                     seg->addr;
0851 
0852                 /* check the dynamic section contains at least
0853                  * one item, and that the last item is a NULL
0854                  * entry */
0855                 if (phdr->p_memsz == 0 ||
0856                     phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
0857                     goto dynamic_error;
0858 
0859                 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
0860                 dyn = (Elf32_Dyn __user *)params->dynamic_addr;
0861                 if (get_user(d_tag, &dyn[tmp - 1].d_tag) ||
0862                     d_tag != 0)
0863                     goto dynamic_error;
0864                 break;
0865             }
0866         }
0867         break;
0868     }
0869 
0870     /* now elide adjacent segments in the load map on MMU linux
0871      * - on uClinux the holes between may actually be filled with system
0872      *   stuff or stuff from other processes
0873      */
0874 #ifdef CONFIG_MMU
0875     nloads = loadmap->nsegs;
0876     mseg = loadmap->segs;
0877     seg = mseg + 1;
0878     for (loop = 1; loop < nloads; loop++) {
0879         /* see if we have a candidate for merging */
0880         if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
0881             load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
0882             if (load_addr == (seg->addr & PAGE_MASK)) {
0883                 mseg->p_memsz +=
0884                     load_addr -
0885                     (mseg->addr + mseg->p_memsz);
0886                 mseg->p_memsz += seg->addr & ~PAGE_MASK;
0887                 mseg->p_memsz += seg->p_memsz;
0888                 loadmap->nsegs--;
0889                 continue;
0890             }
0891         }
0892 
0893         mseg++;
0894         if (mseg != seg)
0895             *mseg = *seg;
0896     }
0897 #endif
0898 
0899     kdebug("Mapped Object [%s]:", what);
0900     kdebug("- elfhdr   : %lx", params->elfhdr_addr);
0901     kdebug("- entry    : %lx", params->entry_addr);
0902     kdebug("- PHDR[]   : %lx", params->ph_addr);
0903     kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
0904     seg = loadmap->segs;
0905     for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
0906         kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
0907                loop,
0908                seg->addr, seg->addr + seg->p_memsz - 1,
0909                seg->p_vaddr, seg->p_memsz);
0910 
0911     return 0;
0912 
0913 dynamic_error:
0914     printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
0915            what, file_inode(file)->i_ino);
0916     return -ELIBBAD;
0917 }
0918 
0919 /*****************************************************************************/
0920 /*
0921  * map a file with constant displacement under uClinux
0922  */
0923 #ifndef CONFIG_MMU
0924 static int elf_fdpic_map_file_constdisp_on_uclinux(
0925     struct elf_fdpic_params *params,
0926     struct file *file,
0927     struct mm_struct *mm)
0928 {
0929     struct elf32_fdpic_loadseg *seg;
0930     struct elf32_phdr *phdr;
0931     unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0;
0932     int loop, ret;
0933 
0934     load_addr = params->load_addr;
0935     seg = params->loadmap->segs;
0936 
0937     /* determine the bounds of the contiguous overall allocation we must
0938      * make */
0939     phdr = params->phdrs;
0940     for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
0941         if (params->phdrs[loop].p_type != PT_LOAD)
0942             continue;
0943 
0944         if (base > phdr->p_vaddr)
0945             base = phdr->p_vaddr;
0946         if (top < phdr->p_vaddr + phdr->p_memsz)
0947             top = phdr->p_vaddr + phdr->p_memsz;
0948     }
0949 
0950     /* allocate one big anon block for everything */
0951     maddr = vm_mmap(NULL, load_addr, top - base,
0952             PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, 0);
0953     if (IS_ERR_VALUE(maddr))
0954         return (int) maddr;
0955 
0956     if (load_addr != 0)
0957         load_addr += PAGE_ALIGN(top - base);
0958 
0959     /* and then load the file segments into it */
0960     phdr = params->phdrs;
0961     for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
0962         if (params->phdrs[loop].p_type != PT_LOAD)
0963             continue;
0964 
0965         seg->addr = maddr + (phdr->p_vaddr - base);
0966         seg->p_vaddr = phdr->p_vaddr;
0967         seg->p_memsz = phdr->p_memsz;
0968 
0969         ret = read_code(file, seg->addr, phdr->p_offset,
0970                        phdr->p_filesz);
0971         if (ret < 0)
0972             return ret;
0973 
0974         /* map the ELF header address if in this segment */
0975         if (phdr->p_offset == 0)
0976             params->elfhdr_addr = seg->addr;
0977 
0978         /* clear any space allocated but not loaded */
0979         if (phdr->p_filesz < phdr->p_memsz) {
0980             if (clear_user((void *) (seg->addr + phdr->p_filesz),
0981                        phdr->p_memsz - phdr->p_filesz))
0982                 return -EFAULT;
0983         }
0984 
0985         if (mm) {
0986             if (phdr->p_flags & PF_X) {
0987                 if (!mm->start_code) {
0988                     mm->start_code = seg->addr;
0989                     mm->end_code = seg->addr +
0990                         phdr->p_memsz;
0991                 }
0992             } else if (!mm->start_data) {
0993                 mm->start_data = seg->addr;
0994                 mm->end_data = seg->addr + phdr->p_memsz;
0995             }
0996         }
0997 
0998         seg++;
0999     }
1000 
1001     return 0;
1002 }
1003 #endif
1004 
1005 /*****************************************************************************/
1006 /*
1007  * map a binary by direct mmap() of the individual PT_LOAD segments
1008  */
1009 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1010                          struct file *file,
1011                          struct mm_struct *mm)
1012 {
1013     struct elf32_fdpic_loadseg *seg;
1014     struct elf32_phdr *phdr;
1015     unsigned long load_addr, delta_vaddr;
1016     int loop, dvset;
1017 
1018     load_addr = params->load_addr;
1019     delta_vaddr = 0;
1020     dvset = 0;
1021 
1022     seg = params->loadmap->segs;
1023 
1024     /* deal with each load segment separately */
1025     phdr = params->phdrs;
1026     for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1027         unsigned long maddr, disp, excess, excess1;
1028         int prot = 0, flags;
1029 
1030         if (phdr->p_type != PT_LOAD)
1031             continue;
1032 
1033         kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1034                (unsigned long) phdr->p_vaddr,
1035                (unsigned long) phdr->p_offset,
1036                (unsigned long) phdr->p_filesz,
1037                (unsigned long) phdr->p_memsz);
1038 
1039         /* determine the mapping parameters */
1040         if (phdr->p_flags & PF_R) prot |= PROT_READ;
1041         if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1042         if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1043 
1044         flags = MAP_PRIVATE;
1045         maddr = 0;
1046 
1047         switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1048         case ELF_FDPIC_FLAG_INDEPENDENT:
1049             /* PT_LOADs are independently locatable */
1050             break;
1051 
1052         case ELF_FDPIC_FLAG_HONOURVADDR:
1053             /* the specified virtual address must be honoured */
1054             maddr = phdr->p_vaddr;
1055             flags |= MAP_FIXED;
1056             break;
1057 
1058         case ELF_FDPIC_FLAG_CONSTDISP:
1059             /* constant displacement
1060              * - can be mapped anywhere, but must be mapped as a
1061              *   unit
1062              */
1063             if (!dvset) {
1064                 maddr = load_addr;
1065                 delta_vaddr = phdr->p_vaddr;
1066                 dvset = 1;
1067             } else {
1068                 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1069                 flags |= MAP_FIXED;
1070             }
1071             break;
1072 
1073         case ELF_FDPIC_FLAG_CONTIGUOUS:
1074             /* contiguity handled later */
1075             break;
1076 
1077         default:
1078             BUG();
1079         }
1080 
1081         maddr &= PAGE_MASK;
1082 
1083         /* create the mapping */
1084         disp = phdr->p_vaddr & ~PAGE_MASK;
1085         maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1086                 phdr->p_offset - disp);
1087 
1088         kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1089                loop, phdr->p_memsz + disp, prot, flags,
1090                phdr->p_offset - disp, maddr);
1091 
1092         if (IS_ERR_VALUE(maddr))
1093             return (int) maddr;
1094 
1095         if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1096             ELF_FDPIC_FLAG_CONTIGUOUS)
1097             load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1098 
1099         seg->addr = maddr + disp;
1100         seg->p_vaddr = phdr->p_vaddr;
1101         seg->p_memsz = phdr->p_memsz;
1102 
1103         /* map the ELF header address if in this segment */
1104         if (phdr->p_offset == 0)
1105             params->elfhdr_addr = seg->addr;
1106 
1107         /* clear the bit between beginning of mapping and beginning of
1108          * PT_LOAD */
1109         if (prot & PROT_WRITE && disp > 0) {
1110             kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1111             if (clear_user((void __user *) maddr, disp))
1112                 return -EFAULT;
1113             maddr += disp;
1114         }
1115 
1116         /* clear any space allocated but not loaded
1117          * - on uClinux we can just clear the lot
1118          * - on MMU linux we'll get a SIGBUS beyond the last page
1119          *   extant in the file
1120          */
1121         excess = phdr->p_memsz - phdr->p_filesz;
1122         excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1123 
1124 #ifdef CONFIG_MMU
1125         if (excess > excess1) {
1126             unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1127             unsigned long xmaddr;
1128 
1129             flags |= MAP_FIXED | MAP_ANONYMOUS;
1130             xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1131                      prot, flags, 0);
1132 
1133             kdebug("mmap[%d] <anon>"
1134                    " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1135                    loop, xaddr, excess - excess1, prot, flags,
1136                    xmaddr);
1137 
1138             if (xmaddr != xaddr)
1139                 return -ENOMEM;
1140         }
1141 
1142         if (prot & PROT_WRITE && excess1 > 0) {
1143             kdebug("clear[%d] ad=%lx sz=%lx",
1144                    loop, maddr + phdr->p_filesz, excess1);
1145             if (clear_user((void __user *) maddr + phdr->p_filesz,
1146                        excess1))
1147                 return -EFAULT;
1148         }
1149 
1150 #else
1151         if (excess > 0) {
1152             kdebug("clear[%d] ad=%lx sz=%lx",
1153                    loop, maddr + phdr->p_filesz, excess);
1154             if (clear_user((void *) maddr + phdr->p_filesz, excess))
1155                 return -EFAULT;
1156         }
1157 #endif
1158 
1159         if (mm) {
1160             if (phdr->p_flags & PF_X) {
1161                 if (!mm->start_code) {
1162                     mm->start_code = maddr;
1163                     mm->end_code = maddr + phdr->p_memsz;
1164                 }
1165             } else if (!mm->start_data) {
1166                 mm->start_data = maddr;
1167                 mm->end_data = maddr + phdr->p_memsz;
1168             }
1169         }
1170 
1171         seg++;
1172     }
1173 
1174     return 0;
1175 }
1176 
1177 /*****************************************************************************/
1178 /*
1179  * ELF-FDPIC core dumper
1180  *
1181  * Modelled on fs/exec.c:aout_core_dump()
1182  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1183  *
1184  * Modelled on fs/binfmt_elf.c core dumper
1185  */
1186 #ifdef CONFIG_ELF_CORE
1187 
1188 struct elf_prstatus_fdpic
1189 {
1190     struct elf_prstatus_common  common;
1191     elf_gregset_t pr_reg;   /* GP registers */
1192     /* When using FDPIC, the loadmap addresses need to be communicated
1193      * to GDB in order for GDB to do the necessary relocations.  The
1194      * fields (below) used to communicate this information are placed
1195      * immediately after ``pr_reg'', so that the loadmap addresses may
1196      * be viewed as part of the register set if so desired.
1197      */
1198     unsigned long pr_exec_fdpic_loadmap;
1199     unsigned long pr_interp_fdpic_loadmap;
1200     int pr_fpvalid;     /* True if math co-processor being used.  */
1201 };
1202 
1203 /* An ELF note in memory */
1204 struct memelfnote
1205 {
1206     const char *name;
1207     int type;
1208     unsigned int datasz;
1209     void *data;
1210 };
1211 
1212 static int notesize(struct memelfnote *en)
1213 {
1214     int sz;
1215 
1216     sz = sizeof(struct elf_note);
1217     sz += roundup(strlen(en->name) + 1, 4);
1218     sz += roundup(en->datasz, 4);
1219 
1220     return sz;
1221 }
1222 
1223 /* #define DEBUG */
1224 
1225 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1226 {
1227     struct elf_note en;
1228     en.n_namesz = strlen(men->name) + 1;
1229     en.n_descsz = men->datasz;
1230     en.n_type = men->type;
1231 
1232     return dump_emit(cprm, &en, sizeof(en)) &&
1233         dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1234         dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1235 }
1236 
1237 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1238 {
1239     memcpy(elf->e_ident, ELFMAG, SELFMAG);
1240     elf->e_ident[EI_CLASS] = ELF_CLASS;
1241     elf->e_ident[EI_DATA] = ELF_DATA;
1242     elf->e_ident[EI_VERSION] = EV_CURRENT;
1243     elf->e_ident[EI_OSABI] = ELF_OSABI;
1244     memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1245 
1246     elf->e_type = ET_CORE;
1247     elf->e_machine = ELF_ARCH;
1248     elf->e_version = EV_CURRENT;
1249     elf->e_entry = 0;
1250     elf->e_phoff = sizeof(struct elfhdr);
1251     elf->e_shoff = 0;
1252     elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1253     elf->e_ehsize = sizeof(struct elfhdr);
1254     elf->e_phentsize = sizeof(struct elf_phdr);
1255     elf->e_phnum = segs;
1256     elf->e_shentsize = 0;
1257     elf->e_shnum = 0;
1258     elf->e_shstrndx = 0;
1259     return;
1260 }
1261 
1262 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1263 {
1264     phdr->p_type = PT_NOTE;
1265     phdr->p_offset = offset;
1266     phdr->p_vaddr = 0;
1267     phdr->p_paddr = 0;
1268     phdr->p_filesz = sz;
1269     phdr->p_memsz = 0;
1270     phdr->p_flags = 0;
1271     phdr->p_align = 0;
1272     return;
1273 }
1274 
1275 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1276         unsigned int sz, void *data)
1277 {
1278     note->name = name;
1279     note->type = type;
1280     note->datasz = sz;
1281     note->data = data;
1282     return;
1283 }
1284 
1285 /*
1286  * fill up all the fields in prstatus from the given task struct, except
1287  * registers which need to be filled up separately.
1288  */
1289 static void fill_prstatus(struct elf_prstatus_common *prstatus,
1290               struct task_struct *p, long signr)
1291 {
1292     prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1293     prstatus->pr_sigpend = p->pending.signal.sig[0];
1294     prstatus->pr_sighold = p->blocked.sig[0];
1295     rcu_read_lock();
1296     prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1297     rcu_read_unlock();
1298     prstatus->pr_pid = task_pid_vnr(p);
1299     prstatus->pr_pgrp = task_pgrp_vnr(p);
1300     prstatus->pr_sid = task_session_vnr(p);
1301     if (thread_group_leader(p)) {
1302         struct task_cputime cputime;
1303 
1304         /*
1305          * This is the record for the group leader.  It shows the
1306          * group-wide total, not its individual thread total.
1307          */
1308         thread_group_cputime(p, &cputime);
1309         prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime);
1310         prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime);
1311     } else {
1312         u64 utime, stime;
1313 
1314         task_cputime(p, &utime, &stime);
1315         prstatus->pr_utime = ns_to_kernel_old_timeval(utime);
1316         prstatus->pr_stime = ns_to_kernel_old_timeval(stime);
1317     }
1318     prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime);
1319     prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime);
1320 }
1321 
1322 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1323                struct mm_struct *mm)
1324 {
1325     const struct cred *cred;
1326     unsigned int i, len;
1327     unsigned int state;
1328 
1329     /* first copy the parameters from user space */
1330     memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1331 
1332     len = mm->arg_end - mm->arg_start;
1333     if (len >= ELF_PRARGSZ)
1334         len = ELF_PRARGSZ - 1;
1335     if (copy_from_user(&psinfo->pr_psargs,
1336                    (const char __user *) mm->arg_start, len))
1337         return -EFAULT;
1338     for (i = 0; i < len; i++)
1339         if (psinfo->pr_psargs[i] == 0)
1340             psinfo->pr_psargs[i] = ' ';
1341     psinfo->pr_psargs[len] = 0;
1342 
1343     rcu_read_lock();
1344     psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1345     rcu_read_unlock();
1346     psinfo->pr_pid = task_pid_vnr(p);
1347     psinfo->pr_pgrp = task_pgrp_vnr(p);
1348     psinfo->pr_sid = task_session_vnr(p);
1349 
1350     state = READ_ONCE(p->__state);
1351     i = state ? ffz(~state) + 1 : 0;
1352     psinfo->pr_state = i;
1353     psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1354     psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1355     psinfo->pr_nice = task_nice(p);
1356     psinfo->pr_flag = p->flags;
1357     rcu_read_lock();
1358     cred = __task_cred(p);
1359     SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1360     SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1361     rcu_read_unlock();
1362     strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1363 
1364     return 0;
1365 }
1366 
1367 /* Here is the structure in which status of each thread is captured. */
1368 struct elf_thread_status
1369 {
1370     struct elf_thread_status *next;
1371     struct elf_prstatus_fdpic prstatus; /* NT_PRSTATUS */
1372     elf_fpregset_t fpu;     /* NT_PRFPREG */
1373     struct memelfnote notes[2];
1374     int num_notes;
1375 };
1376 
1377 /*
1378  * In order to add the specific thread information for the elf file format,
1379  * we need to keep a linked list of every thread's pr_status and then create
1380  * a single section for them in the final core file.
1381  */
1382 static struct elf_thread_status *elf_dump_thread_status(long signr, struct task_struct *p, int *sz)
1383 {
1384     const struct user_regset_view *view = task_user_regset_view(p);
1385     struct elf_thread_status *t;
1386     int i, ret;
1387 
1388     t = kzalloc(sizeof(struct elf_thread_status), GFP_KERNEL);
1389     if (!t)
1390         return t;
1391 
1392     fill_prstatus(&t->prstatus.common, p, signr);
1393     t->prstatus.pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1394     t->prstatus.pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1395     regset_get(p, &view->regsets[0],
1396            sizeof(t->prstatus.pr_reg), &t->prstatus.pr_reg);
1397 
1398     fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1399           &t->prstatus);
1400     t->num_notes++;
1401     *sz += notesize(&t->notes[0]);
1402 
1403     for (i = 1; i < view->n; ++i) {
1404         const struct user_regset *regset = &view->regsets[i];
1405         if (regset->core_note_type != NT_PRFPREG)
1406             continue;
1407         if (regset->active && regset->active(p, regset) <= 0)
1408             continue;
1409         ret = regset_get(p, regset, sizeof(t->fpu), &t->fpu);
1410         if (ret >= 0)
1411             t->prstatus.pr_fpvalid = 1;
1412         break;
1413     }
1414 
1415     if (t->prstatus.pr_fpvalid) {
1416         fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1417               &t->fpu);
1418         t->num_notes++;
1419         *sz += notesize(&t->notes[1]);
1420     }
1421     return t;
1422 }
1423 
1424 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1425                  elf_addr_t e_shoff, int segs)
1426 {
1427     elf->e_shoff = e_shoff;
1428     elf->e_shentsize = sizeof(*shdr4extnum);
1429     elf->e_shnum = 1;
1430     elf->e_shstrndx = SHN_UNDEF;
1431 
1432     memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1433 
1434     shdr4extnum->sh_type = SHT_NULL;
1435     shdr4extnum->sh_size = elf->e_shnum;
1436     shdr4extnum->sh_link = elf->e_shstrndx;
1437     shdr4extnum->sh_info = segs;
1438 }
1439 
1440 /*
1441  * dump the segments for an MMU process
1442  */
1443 static bool elf_fdpic_dump_segments(struct coredump_params *cprm,
1444                     struct core_vma_metadata *vma_meta,
1445                     int vma_count)
1446 {
1447     int i;
1448 
1449     for (i = 0; i < vma_count; i++) {
1450         struct core_vma_metadata *meta = vma_meta + i;
1451 
1452         if (!dump_user_range(cprm, meta->start, meta->dump_size))
1453             return false;
1454     }
1455     return true;
1456 }
1457 
1458 /*
1459  * Actual dumper
1460  *
1461  * This is a two-pass process; first we find the offsets of the bits,
1462  * and then they are actually written out.  If we run out of core limit
1463  * we just truncate.
1464  */
1465 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1466 {
1467     int has_dumped = 0;
1468     int segs;
1469     int i;
1470     struct elfhdr *elf = NULL;
1471     loff_t offset = 0, dataoff;
1472     struct memelfnote psinfo_note, auxv_note;
1473     struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1474     struct elf_thread_status *thread_list = NULL;
1475     int thread_status_size = 0;
1476     elf_addr_t *auxv;
1477     struct elf_phdr *phdr4note = NULL;
1478     struct elf_shdr *shdr4extnum = NULL;
1479     Elf_Half e_phnum;
1480     elf_addr_t e_shoff;
1481     struct core_thread *ct;
1482     struct elf_thread_status *tmp;
1483 
1484     /* alloc memory for large data structures: too large to be on stack */
1485     elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1486     if (!elf)
1487         goto end_coredump;
1488     psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1489     if (!psinfo)
1490         goto end_coredump;
1491 
1492     for (ct = current->signal->core_state->dumper.next;
1493                     ct; ct = ct->next) {
1494         tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
1495                          ct->task, &thread_status_size);
1496         if (!tmp)
1497             goto end_coredump;
1498 
1499         tmp->next = thread_list;
1500         thread_list = tmp;
1501     }
1502 
1503     /* now collect the dump for the current */
1504     tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
1505                      current, &thread_status_size);
1506     if (!tmp)
1507         goto end_coredump;
1508     tmp->next = thread_list;
1509     thread_list = tmp;
1510 
1511     segs = cprm->vma_count + elf_core_extra_phdrs();
1512 
1513     /* for notes section */
1514     segs++;
1515 
1516     /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1517      * this, kernel supports extended numbering. Have a look at
1518      * include/linux/elf.h for further information. */
1519     e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1520 
1521     /* Set up header */
1522     fill_elf_fdpic_header(elf, e_phnum);
1523 
1524     has_dumped = 1;
1525     /*
1526      * Set up the notes in similar form to SVR4 core dumps made
1527      * with info from their /proc.
1528      */
1529 
1530     fill_psinfo(psinfo, current->group_leader, current->mm);
1531     fill_note(&psinfo_note, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1532     thread_status_size += notesize(&psinfo_note);
1533 
1534     auxv = (elf_addr_t *) current->mm->saved_auxv;
1535     i = 0;
1536     do
1537         i += 2;
1538     while (auxv[i - 2] != AT_NULL);
1539     fill_note(&auxv_note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1540     thread_status_size += notesize(&auxv_note);
1541 
1542     offset = sizeof(*elf);              /* Elf header */
1543     offset += segs * sizeof(struct elf_phdr);   /* Program headers */
1544 
1545     /* Write notes phdr entry */
1546     phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1547     if (!phdr4note)
1548         goto end_coredump;
1549 
1550     fill_elf_note_phdr(phdr4note, thread_status_size, offset);
1551     offset += thread_status_size;
1552 
1553     /* Page-align dumped data */
1554     dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1555 
1556     offset += cprm->vma_data_size;
1557     offset += elf_core_extra_data_size();
1558     e_shoff = offset;
1559 
1560     if (e_phnum == PN_XNUM) {
1561         shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1562         if (!shdr4extnum)
1563             goto end_coredump;
1564         fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1565     }
1566 
1567     offset = dataoff;
1568 
1569     if (!dump_emit(cprm, elf, sizeof(*elf)))
1570         goto end_coredump;
1571 
1572     if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
1573         goto end_coredump;
1574 
1575     /* write program headers for segments dump */
1576     for (i = 0; i < cprm->vma_count; i++) {
1577         struct core_vma_metadata *meta = cprm->vma_meta + i;
1578         struct elf_phdr phdr;
1579         size_t sz;
1580 
1581         sz = meta->end - meta->start;
1582 
1583         phdr.p_type = PT_LOAD;
1584         phdr.p_offset = offset;
1585         phdr.p_vaddr = meta->start;
1586         phdr.p_paddr = 0;
1587         phdr.p_filesz = meta->dump_size;
1588         phdr.p_memsz = sz;
1589         offset += phdr.p_filesz;
1590         phdr.p_flags = 0;
1591         if (meta->flags & VM_READ)
1592             phdr.p_flags |= PF_R;
1593         if (meta->flags & VM_WRITE)
1594             phdr.p_flags |= PF_W;
1595         if (meta->flags & VM_EXEC)
1596             phdr.p_flags |= PF_X;
1597         phdr.p_align = ELF_EXEC_PAGESIZE;
1598 
1599         if (!dump_emit(cprm, &phdr, sizeof(phdr)))
1600             goto end_coredump;
1601     }
1602 
1603     if (!elf_core_write_extra_phdrs(cprm, offset))
1604         goto end_coredump;
1605 
1606     /* write out the notes section */
1607     if (!writenote(thread_list->notes, cprm))
1608         goto end_coredump;
1609     if (!writenote(&psinfo_note, cprm))
1610         goto end_coredump;
1611     if (!writenote(&auxv_note, cprm))
1612         goto end_coredump;
1613     for (i = 1; i < thread_list->num_notes; i++)
1614         if (!writenote(thread_list->notes + i, cprm))
1615             goto end_coredump;
1616 
1617     /* write out the thread status notes section */
1618     for (tmp = thread_list->next; tmp; tmp = tmp->next) {
1619         for (i = 0; i < tmp->num_notes; i++)
1620             if (!writenote(&tmp->notes[i], cprm))
1621                 goto end_coredump;
1622     }
1623 
1624     dump_skip_to(cprm, dataoff);
1625 
1626     if (!elf_fdpic_dump_segments(cprm, cprm->vma_meta, cprm->vma_count))
1627         goto end_coredump;
1628 
1629     if (!elf_core_write_extra_data(cprm))
1630         goto end_coredump;
1631 
1632     if (e_phnum == PN_XNUM) {
1633         if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
1634             goto end_coredump;
1635     }
1636 
1637     if (cprm->file->f_pos != offset) {
1638         /* Sanity check */
1639         printk(KERN_WARNING
1640                "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1641                cprm->file->f_pos, offset);
1642     }
1643 
1644 end_coredump:
1645     while (thread_list) {
1646         tmp = thread_list;
1647         thread_list = thread_list->next;
1648         kfree(tmp);
1649     }
1650     kfree(phdr4note);
1651     kfree(elf);
1652     kfree(psinfo);
1653     kfree(shdr4extnum);
1654     return has_dumped;
1655 }
1656 
1657 #endif      /* CONFIG_ELF_CORE */
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