2399 lines
63 KiB
C
2399 lines
63 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* linux/fs/binfmt_elf.c
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*
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* These are the functions used to load ELF format executables as used
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* on SVr4 machines. Information on the format may be found in the book
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* "UNIX SYSTEM V RELEASE 4 Programmers Guide: Ansi C and Programming Support
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* Tools".
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*
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* Copyright 1993, 1994: Eric Youngdale (ericy@cais.com).
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/mman.h>
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#include <linux/errno.h>
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#include <linux/signal.h>
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#include <linux/binfmts.h>
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#include <linux/string.h>
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#include <linux/file.h>
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#include <linux/slab.h>
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#include <linux/personality.h>
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#include <linux/elfcore.h>
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#include <linux/init.h>
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#include <linux/highuid.h>
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#include <linux/compiler.h>
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#include <linux/highmem.h>
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#include <linux/pagemap.h>
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#include <linux/vmalloc.h>
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#include <linux/security.h>
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#include <linux/random.h>
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#include <linux/elf.h>
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#include <linux/elf-randomize.h>
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#include <linux/utsname.h>
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#include <linux/coredump.h>
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#include <linux/sched.h>
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#include <linux/sched/coredump.h>
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#include <linux/sched/task_stack.h>
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#include <linux/sched/cputime.h>
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#include <linux/cred.h>
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#include <linux/dax.h>
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#include <linux/uaccess.h>
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#include <asm/param.h>
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#include <asm/page.h>
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#ifndef user_long_t
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#define user_long_t long
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#endif
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#ifndef user_siginfo_t
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#define user_siginfo_t siginfo_t
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#endif
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/* That's for binfmt_elf_fdpic to deal with */
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#ifndef elf_check_fdpic
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#define elf_check_fdpic(ex) false
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#endif
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static int load_elf_binary(struct linux_binprm *bprm);
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#ifdef CONFIG_USELIB
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static int load_elf_library(struct file *);
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#else
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#define load_elf_library NULL
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#endif
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/*
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* If we don't support core dumping, then supply a NULL so we
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* don't even try.
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*/
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#ifdef CONFIG_ELF_CORE
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static int elf_core_dump(struct coredump_params *cprm);
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#else
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#define elf_core_dump NULL
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#endif
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#if ELF_EXEC_PAGESIZE > PAGE_SIZE
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#define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
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#else
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#define ELF_MIN_ALIGN PAGE_SIZE
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#endif
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#ifndef ELF_CORE_EFLAGS
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#define ELF_CORE_EFLAGS 0
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#endif
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#define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
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#define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
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#define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
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static struct linux_binfmt elf_format = {
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.module = THIS_MODULE,
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.load_binary = load_elf_binary,
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.load_shlib = load_elf_library,
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.core_dump = elf_core_dump,
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.min_coredump = ELF_EXEC_PAGESIZE,
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};
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#define BAD_ADDR(x) (unlikely((unsigned long)(x) >= TASK_SIZE))
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static int set_brk(unsigned long start, unsigned long end, int prot)
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{
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start = ELF_PAGEALIGN(start);
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end = ELF_PAGEALIGN(end);
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if (end > start) {
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/*
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* Map the last of the bss segment.
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* If the header is requesting these pages to be
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* executable, honour that (ppc32 needs this).
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*/
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int error = vm_brk_flags(start, end - start,
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prot & PROT_EXEC ? VM_EXEC : 0);
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if (error)
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return error;
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}
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current->mm->start_brk = current->mm->brk = end;
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return 0;
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}
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/* We need to explicitly zero any fractional pages
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after the data section (i.e. bss). This would
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contain the junk from the file that should not
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be in memory
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*/
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static int padzero(unsigned long elf_bss)
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{
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unsigned long nbyte;
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nbyte = ELF_PAGEOFFSET(elf_bss);
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if (nbyte) {
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nbyte = ELF_MIN_ALIGN - nbyte;
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if (clear_user((void __user *) elf_bss, nbyte))
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return -EFAULT;
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}
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return 0;
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}
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/* Let's use some macros to make this stack manipulation a little clearer */
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#ifdef CONFIG_STACK_GROWSUP
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#define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
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#define STACK_ROUND(sp, items) \
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((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
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#define STACK_ALLOC(sp, len) ({ \
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elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
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old_sp; })
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#else
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#define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
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#define STACK_ROUND(sp, items) \
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(((unsigned long) (sp - items)) &~ 15UL)
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#define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
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#endif
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#ifndef ELF_BASE_PLATFORM
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/*
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* AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
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* If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
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* will be copied to the user stack in the same manner as AT_PLATFORM.
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*/
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#define ELF_BASE_PLATFORM NULL
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#endif
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static int
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create_elf_tables(struct linux_binprm *bprm, const struct elfhdr *exec,
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unsigned long load_addr, unsigned long interp_load_addr,
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unsigned long e_entry)
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{
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struct mm_struct *mm = current->mm;
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unsigned long p = bprm->p;
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int argc = bprm->argc;
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int envc = bprm->envc;
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elf_addr_t __user *sp;
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elf_addr_t __user *u_platform;
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elf_addr_t __user *u_base_platform;
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elf_addr_t __user *u_rand_bytes;
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const char *k_platform = ELF_PLATFORM;
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const char *k_base_platform = ELF_BASE_PLATFORM;
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unsigned char k_rand_bytes[16];
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int items;
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elf_addr_t *elf_info;
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int ei_index;
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const struct cred *cred = current_cred();
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struct vm_area_struct *vma;
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/*
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* In some cases (e.g. Hyper-Threading), we want to avoid L1
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* evictions by the processes running on the same package. One
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* thing we can do is to shuffle the initial stack for them.
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*/
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p = arch_align_stack(p);
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/*
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* If this architecture has a platform capability string, copy it
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* to userspace. In some cases (Sparc), this info is impossible
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* for userspace to get any other way, in others (i386) it is
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* merely difficult.
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*/
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u_platform = NULL;
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if (k_platform) {
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size_t len = strlen(k_platform) + 1;
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u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
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if (__copy_to_user(u_platform, k_platform, len))
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return -EFAULT;
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}
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/*
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* If this architecture has a "base" platform capability
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* string, copy it to userspace.
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*/
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u_base_platform = NULL;
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if (k_base_platform) {
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size_t len = strlen(k_base_platform) + 1;
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u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
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if (__copy_to_user(u_base_platform, k_base_platform, len))
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return -EFAULT;
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}
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/*
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* Generate 16 random bytes for userspace PRNG seeding.
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*/
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get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));
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u_rand_bytes = (elf_addr_t __user *)
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STACK_ALLOC(p, sizeof(k_rand_bytes));
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if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes)))
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return -EFAULT;
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/* Create the ELF interpreter info */
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elf_info = (elf_addr_t *)mm->saved_auxv;
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/* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
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#define NEW_AUX_ENT(id, val) \
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do { \
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*elf_info++ = id; \
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*elf_info++ = val; \
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} while (0)
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#ifdef ARCH_DLINFO
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/*
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* ARCH_DLINFO must come first so PPC can do its special alignment of
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* AUXV.
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* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
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* ARCH_DLINFO changes
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*/
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ARCH_DLINFO;
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#endif
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NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
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NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
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NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
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NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
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NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
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NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
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NEW_AUX_ENT(AT_BASE, interp_load_addr);
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NEW_AUX_ENT(AT_FLAGS, 0);
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NEW_AUX_ENT(AT_ENTRY, e_entry);
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NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid));
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NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid));
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NEW_AUX_ENT(AT_GID, from_kgid_munged(cred->user_ns, cred->gid));
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NEW_AUX_ENT(AT_EGID, from_kgid_munged(cred->user_ns, cred->egid));
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NEW_AUX_ENT(AT_SECURE, bprm->secureexec);
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NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
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#ifdef ELF_HWCAP2
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NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
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#endif
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NEW_AUX_ENT(AT_EXECFN, bprm->exec);
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if (k_platform) {
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NEW_AUX_ENT(AT_PLATFORM,
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(elf_addr_t)(unsigned long)u_platform);
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}
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if (k_base_platform) {
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NEW_AUX_ENT(AT_BASE_PLATFORM,
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(elf_addr_t)(unsigned long)u_base_platform);
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}
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if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
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NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
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}
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#undef NEW_AUX_ENT
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/* AT_NULL is zero; clear the rest too */
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memset(elf_info, 0, (char *)mm->saved_auxv +
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sizeof(mm->saved_auxv) - (char *)elf_info);
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/* And advance past the AT_NULL entry. */
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elf_info += 2;
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ei_index = elf_info - (elf_addr_t *)mm->saved_auxv;
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sp = STACK_ADD(p, ei_index);
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items = (argc + 1) + (envc + 1) + 1;
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bprm->p = STACK_ROUND(sp, items);
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/* Point sp at the lowest address on the stack */
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#ifdef CONFIG_STACK_GROWSUP
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sp = (elf_addr_t __user *)bprm->p - items - ei_index;
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bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
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#else
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sp = (elf_addr_t __user *)bprm->p;
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#endif
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/*
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* Grow the stack manually; some architectures have a limit on how
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* far ahead a user-space access may be in order to grow the stack.
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*/
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vma = find_extend_vma(mm, bprm->p);
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if (!vma)
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return -EFAULT;
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/* Now, let's put argc (and argv, envp if appropriate) on the stack */
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if (__put_user(argc, sp++))
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return -EFAULT;
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/* Populate list of argv pointers back to argv strings. */
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p = mm->arg_end = mm->arg_start;
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while (argc-- > 0) {
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size_t len;
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if (__put_user((elf_addr_t)p, sp++))
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return -EFAULT;
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len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
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if (!len || len > MAX_ARG_STRLEN)
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return -EINVAL;
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p += len;
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}
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if (__put_user(0, sp++))
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return -EFAULT;
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mm->arg_end = p;
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/* Populate list of envp pointers back to envp strings. */
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mm->env_end = mm->env_start = p;
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while (envc-- > 0) {
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size_t len;
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if (__put_user((elf_addr_t)p, sp++))
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return -EFAULT;
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len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
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if (!len || len > MAX_ARG_STRLEN)
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return -EINVAL;
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p += len;
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}
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if (__put_user(0, sp++))
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return -EFAULT;
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mm->env_end = p;
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/* Put the elf_info on the stack in the right place. */
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if (copy_to_user(sp, mm->saved_auxv, ei_index * sizeof(elf_addr_t)))
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return -EFAULT;
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return 0;
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}
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#ifndef elf_map
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static unsigned long elf_map(struct file *filep, unsigned long addr,
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const struct elf_phdr *eppnt, int prot, int type,
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unsigned long total_size)
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{
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unsigned long map_addr;
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unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
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unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
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addr = ELF_PAGESTART(addr);
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size = ELF_PAGEALIGN(size);
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/* mmap() will return -EINVAL if given a zero size, but a
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* segment with zero filesize is perfectly valid */
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if (!size)
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return addr;
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/*
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* total_size is the size of the ELF (interpreter) image.
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* The _first_ mmap needs to know the full size, otherwise
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* randomization might put this image into an overlapping
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* position with the ELF binary image. (since size < total_size)
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* So we first map the 'big' image - and unmap the remainder at
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* the end. (which unmap is needed for ELF images with holes.)
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*/
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if (total_size) {
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total_size = ELF_PAGEALIGN(total_size);
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map_addr = vm_mmap(filep, addr, total_size, prot, type, off);
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if (!BAD_ADDR(map_addr))
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vm_munmap(map_addr+size, total_size-size);
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} else
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map_addr = vm_mmap(filep, addr, size, prot, type, off);
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if ((type & MAP_FIXED_NOREPLACE) &&
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PTR_ERR((void *)map_addr) == -EEXIST)
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pr_info("%d (%s): Uhuuh, elf segment at %px requested but the memory is mapped already\n",
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task_pid_nr(current), current->comm, (void *)addr);
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return(map_addr);
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}
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#endif /* !elf_map */
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static unsigned long total_mapping_size(const struct elf_phdr *cmds, int nr)
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{
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int i, first_idx = -1, last_idx = -1;
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for (i = 0; i < nr; i++) {
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if (cmds[i].p_type == PT_LOAD) {
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last_idx = i;
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if (first_idx == -1)
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first_idx = i;
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}
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}
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if (first_idx == -1)
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return 0;
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return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
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ELF_PAGESTART(cmds[first_idx].p_vaddr);
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}
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static int elf_read(struct file *file, void *buf, size_t len, loff_t pos)
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{
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ssize_t rv;
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rv = kernel_read(file, buf, len, &pos);
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if (unlikely(rv != len)) {
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return (rv < 0) ? rv : -EIO;
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}
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return 0;
|
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}
|
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|
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/**
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* load_elf_phdrs() - load ELF program headers
|
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* @elf_ex: ELF header of the binary whose program headers should be loaded
|
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* @elf_file: the opened ELF binary file
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*
|
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* Loads ELF program headers from the binary file elf_file, which has the ELF
|
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* header pointed to by elf_ex, into a newly allocated array. The caller is
|
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* responsible for freeing the allocated data. Returns an ERR_PTR upon failure.
|
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*/
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static struct elf_phdr *load_elf_phdrs(const struct elfhdr *elf_ex,
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struct file *elf_file)
|
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{
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struct elf_phdr *elf_phdata = NULL;
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int retval, err = -1;
|
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unsigned int size;
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|
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/*
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* If the size of this structure has changed, then punt, since
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* we will be doing the wrong thing.
|
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*/
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if (elf_ex->e_phentsize != sizeof(struct elf_phdr))
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goto out;
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|
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/* Sanity check the number of program headers... */
|
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/* ...and their total size. */
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size = sizeof(struct elf_phdr) * elf_ex->e_phnum;
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if (size == 0 || size > 65536 || size > ELF_MIN_ALIGN)
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goto out;
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|
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elf_phdata = kmalloc(size, GFP_KERNEL);
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if (!elf_phdata)
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goto out;
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|
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/* Read in the program headers */
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retval = elf_read(elf_file, elf_phdata, size, elf_ex->e_phoff);
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if (retval < 0) {
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err = retval;
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goto out;
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}
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|
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/* Success! */
|
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err = 0;
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out:
|
|
if (err) {
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kfree(elf_phdata);
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elf_phdata = NULL;
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}
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return elf_phdata;
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}
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|
|
#ifndef CONFIG_ARCH_BINFMT_ELF_STATE
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|
|
/**
|
|
* struct arch_elf_state - arch-specific ELF loading state
|
|
*
|
|
* This structure is used to preserve architecture specific data during
|
|
* the loading of an ELF file, throughout the checking of architecture
|
|
* specific ELF headers & through to the point where the ELF load is
|
|
* known to be proceeding (ie. SET_PERSONALITY).
|
|
*
|
|
* This implementation is a dummy for architectures which require no
|
|
* specific state.
|
|
*/
|
|
struct arch_elf_state {
|
|
};
|
|
|
|
#define INIT_ARCH_ELF_STATE {}
|
|
|
|
/**
|
|
* arch_elf_pt_proc() - check a PT_LOPROC..PT_HIPROC ELF program header
|
|
* @ehdr: The main ELF header
|
|
* @phdr: The program header to check
|
|
* @elf: The open ELF file
|
|
* @is_interp: True if the phdr is from the interpreter of the ELF being
|
|
* loaded, else false.
|
|
* @state: Architecture-specific state preserved throughout the process
|
|
* of loading the ELF.
|
|
*
|
|
* Inspects the program header phdr to validate its correctness and/or
|
|
* suitability for the system. Called once per ELF program header in the
|
|
* range PT_LOPROC to PT_HIPROC, for both the ELF being loaded and its
|
|
* interpreter.
|
|
*
|
|
* Return: Zero to proceed with the ELF load, non-zero to fail the ELF load
|
|
* with that return code.
|
|
*/
|
|
static inline int arch_elf_pt_proc(struct elfhdr *ehdr,
|
|
struct elf_phdr *phdr,
|
|
struct file *elf, bool is_interp,
|
|
struct arch_elf_state *state)
|
|
{
|
|
/* Dummy implementation, always proceed */
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* arch_check_elf() - check an ELF executable
|
|
* @ehdr: The main ELF header
|
|
* @has_interp: True if the ELF has an interpreter, else false.
|
|
* @interp_ehdr: The interpreter's ELF header
|
|
* @state: Architecture-specific state preserved throughout the process
|
|
* of loading the ELF.
|
|
*
|
|
* Provides a final opportunity for architecture code to reject the loading
|
|
* of the ELF & cause an exec syscall to return an error. This is called after
|
|
* all program headers to be checked by arch_elf_pt_proc have been.
|
|
*
|
|
* Return: Zero to proceed with the ELF load, non-zero to fail the ELF load
|
|
* with that return code.
|
|
*/
|
|
static inline int arch_check_elf(struct elfhdr *ehdr, bool has_interp,
|
|
struct elfhdr *interp_ehdr,
|
|
struct arch_elf_state *state)
|
|
{
|
|
/* Dummy implementation, always proceed */
|
|
return 0;
|
|
}
|
|
|
|
#endif /* !CONFIG_ARCH_BINFMT_ELF_STATE */
|
|
|
|
static inline int make_prot(u32 p_flags)
|
|
{
|
|
int prot = 0;
|
|
|
|
if (p_flags & PF_R)
|
|
prot |= PROT_READ;
|
|
if (p_flags & PF_W)
|
|
prot |= PROT_WRITE;
|
|
if (p_flags & PF_X)
|
|
prot |= PROT_EXEC;
|
|
return prot;
|
|
}
|
|
|
|
/* This is much more generalized than the library routine read function,
|
|
so we keep this separate. Technically the library read function
|
|
is only provided so that we can read a.out libraries that have
|
|
an ELF header */
|
|
|
|
static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
|
|
struct file *interpreter,
|
|
unsigned long no_base, struct elf_phdr *interp_elf_phdata)
|
|
{
|
|
struct elf_phdr *eppnt;
|
|
unsigned long load_addr = 0;
|
|
int load_addr_set = 0;
|
|
unsigned long last_bss = 0, elf_bss = 0;
|
|
int bss_prot = 0;
|
|
unsigned long error = ~0UL;
|
|
unsigned long total_size;
|
|
int i;
|
|
|
|
/* First of all, some simple consistency checks */
|
|
if (interp_elf_ex->e_type != ET_EXEC &&
|
|
interp_elf_ex->e_type != ET_DYN)
|
|
goto out;
|
|
if (!elf_check_arch(interp_elf_ex) ||
|
|
elf_check_fdpic(interp_elf_ex))
|
|
goto out;
|
|
if (!interpreter->f_op->mmap)
|
|
goto out;
|
|
|
|
total_size = total_mapping_size(interp_elf_phdata,
|
|
interp_elf_ex->e_phnum);
|
|
if (!total_size) {
|
|
error = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
eppnt = interp_elf_phdata;
|
|
for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
|
|
if (eppnt->p_type == PT_LOAD) {
|
|
int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
|
|
int elf_prot = make_prot(eppnt->p_flags);
|
|
unsigned long vaddr = 0;
|
|
unsigned long k, map_addr;
|
|
|
|
vaddr = eppnt->p_vaddr;
|
|
if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
|
|
elf_type |= MAP_FIXED_NOREPLACE;
|
|
else if (no_base && interp_elf_ex->e_type == ET_DYN)
|
|
load_addr = -vaddr;
|
|
|
|
map_addr = elf_map(interpreter, load_addr + vaddr,
|
|
eppnt, elf_prot, elf_type, total_size);
|
|
total_size = 0;
|
|
error = map_addr;
|
|
if (BAD_ADDR(map_addr))
|
|
goto out;
|
|
|
|
if (!load_addr_set &&
|
|
interp_elf_ex->e_type == ET_DYN) {
|
|
load_addr = map_addr - ELF_PAGESTART(vaddr);
|
|
load_addr_set = 1;
|
|
}
|
|
|
|
/*
|
|
* Check to see if the section's size will overflow the
|
|
* allowed task size. Note that p_filesz must always be
|
|
* <= p_memsize so it's only necessary to check p_memsz.
|
|
*/
|
|
k = load_addr + eppnt->p_vaddr;
|
|
if (BAD_ADDR(k) ||
|
|
eppnt->p_filesz > eppnt->p_memsz ||
|
|
eppnt->p_memsz > TASK_SIZE ||
|
|
TASK_SIZE - eppnt->p_memsz < k) {
|
|
error = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Find the end of the file mapping for this phdr, and
|
|
* keep track of the largest address we see for this.
|
|
*/
|
|
k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
|
|
if (k > elf_bss)
|
|
elf_bss = k;
|
|
|
|
/*
|
|
* Do the same thing for the memory mapping - between
|
|
* elf_bss and last_bss is the bss section.
|
|
*/
|
|
k = load_addr + eppnt->p_vaddr + eppnt->p_memsz;
|
|
if (k > last_bss) {
|
|
last_bss = k;
|
|
bss_prot = elf_prot;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Now fill out the bss section: first pad the last page from
|
|
* the file up to the page boundary, and zero it from elf_bss
|
|
* up to the end of the page.
|
|
*/
|
|
if (padzero(elf_bss)) {
|
|
error = -EFAULT;
|
|
goto out;
|
|
}
|
|
/*
|
|
* Next, align both the file and mem bss up to the page size,
|
|
* since this is where elf_bss was just zeroed up to, and where
|
|
* last_bss will end after the vm_brk_flags() below.
|
|
*/
|
|
elf_bss = ELF_PAGEALIGN(elf_bss);
|
|
last_bss = ELF_PAGEALIGN(last_bss);
|
|
/* Finally, if there is still more bss to allocate, do it. */
|
|
if (last_bss > elf_bss) {
|
|
error = vm_brk_flags(elf_bss, last_bss - elf_bss,
|
|
bss_prot & PROT_EXEC ? VM_EXEC : 0);
|
|
if (error)
|
|
goto out;
|
|
}
|
|
|
|
error = load_addr;
|
|
out:
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* These are the functions used to load ELF style executables and shared
|
|
* libraries. There is no binary dependent code anywhere else.
|
|
*/
|
|
|
|
static int load_elf_binary(struct linux_binprm *bprm)
|
|
{
|
|
struct file *interpreter = NULL; /* to shut gcc up */
|
|
unsigned long load_addr = 0, load_bias = 0;
|
|
int load_addr_set = 0;
|
|
unsigned long error;
|
|
struct elf_phdr *elf_ppnt, *elf_phdata, *interp_elf_phdata = NULL;
|
|
unsigned long elf_bss, elf_brk;
|
|
int bss_prot = 0;
|
|
int retval, i;
|
|
unsigned long elf_entry;
|
|
unsigned long e_entry;
|
|
unsigned long interp_load_addr = 0;
|
|
unsigned long start_code, end_code, start_data, end_data;
|
|
unsigned long reloc_func_desc __maybe_unused = 0;
|
|
int executable_stack = EXSTACK_DEFAULT;
|
|
struct elfhdr *elf_ex = (struct elfhdr *)bprm->buf;
|
|
struct {
|
|
struct elfhdr interp_elf_ex;
|
|
} *loc;
|
|
struct arch_elf_state arch_state = INIT_ARCH_ELF_STATE;
|
|
struct mm_struct *mm;
|
|
struct pt_regs *regs;
|
|
|
|
loc = kmalloc(sizeof(*loc), GFP_KERNEL);
|
|
if (!loc) {
|
|
retval = -ENOMEM;
|
|
goto out_ret;
|
|
}
|
|
|
|
retval = -ENOEXEC;
|
|
/* First of all, some simple consistency checks */
|
|
if (memcmp(elf_ex->e_ident, ELFMAG, SELFMAG) != 0)
|
|
goto out;
|
|
|
|
if (elf_ex->e_type != ET_EXEC && elf_ex->e_type != ET_DYN)
|
|
goto out;
|
|
if (!elf_check_arch(elf_ex))
|
|
goto out;
|
|
if (elf_check_fdpic(elf_ex))
|
|
goto out;
|
|
if (!bprm->file->f_op->mmap)
|
|
goto out;
|
|
|
|
elf_phdata = load_elf_phdrs(elf_ex, bprm->file);
|
|
if (!elf_phdata)
|
|
goto out;
|
|
|
|
elf_ppnt = elf_phdata;
|
|
for (i = 0; i < elf_ex->e_phnum; i++, elf_ppnt++) {
|
|
char *elf_interpreter;
|
|
|
|
if (elf_ppnt->p_type != PT_INTERP)
|
|
continue;
|
|
|
|
/*
|
|
* This is the program interpreter used for shared libraries -
|
|
* for now assume that this is an a.out format binary.
|
|
*/
|
|
retval = -ENOEXEC;
|
|
if (elf_ppnt->p_filesz > PATH_MAX || elf_ppnt->p_filesz < 2)
|
|
goto out_free_ph;
|
|
|
|
retval = -ENOMEM;
|
|
elf_interpreter = kmalloc(elf_ppnt->p_filesz, GFP_KERNEL);
|
|
if (!elf_interpreter)
|
|
goto out_free_ph;
|
|
|
|
retval = elf_read(bprm->file, elf_interpreter, elf_ppnt->p_filesz,
|
|
elf_ppnt->p_offset);
|
|
if (retval < 0)
|
|
goto out_free_interp;
|
|
/* make sure path is NULL terminated */
|
|
retval = -ENOEXEC;
|
|
if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
|
|
goto out_free_interp;
|
|
|
|
interpreter = open_exec(elf_interpreter);
|
|
kfree(elf_interpreter);
|
|
retval = PTR_ERR(interpreter);
|
|
if (IS_ERR(interpreter))
|
|
goto out_free_ph;
|
|
|
|
/*
|
|
* If the binary is not readable then enforce mm->dumpable = 0
|
|
* regardless of the interpreter's permissions.
|
|
*/
|
|
would_dump(bprm, interpreter);
|
|
|
|
/* Get the exec headers */
|
|
retval = elf_read(interpreter, &loc->interp_elf_ex,
|
|
sizeof(loc->interp_elf_ex), 0);
|
|
if (retval < 0)
|
|
goto out_free_dentry;
|
|
|
|
break;
|
|
|
|
out_free_interp:
|
|
kfree(elf_interpreter);
|
|
goto out_free_ph;
|
|
}
|
|
|
|
elf_ppnt = elf_phdata;
|
|
for (i = 0; i < elf_ex->e_phnum; i++, elf_ppnt++)
|
|
switch (elf_ppnt->p_type) {
|
|
case PT_GNU_STACK:
|
|
if (elf_ppnt->p_flags & PF_X)
|
|
executable_stack = EXSTACK_ENABLE_X;
|
|
else
|
|
executable_stack = EXSTACK_DISABLE_X;
|
|
break;
|
|
|
|
case PT_LOPROC ... PT_HIPROC:
|
|
retval = arch_elf_pt_proc(elf_ex, elf_ppnt,
|
|
bprm->file, false,
|
|
&arch_state);
|
|
if (retval)
|
|
goto out_free_dentry;
|
|
break;
|
|
}
|
|
|
|
/* Some simple consistency checks for the interpreter */
|
|
if (interpreter) {
|
|
retval = -ELIBBAD;
|
|
/* Not an ELF interpreter */
|
|
if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
|
|
goto out_free_dentry;
|
|
/* Verify the interpreter has a valid arch */
|
|
if (!elf_check_arch(&loc->interp_elf_ex) ||
|
|
elf_check_fdpic(&loc->interp_elf_ex))
|
|
goto out_free_dentry;
|
|
|
|
/* Load the interpreter program headers */
|
|
interp_elf_phdata = load_elf_phdrs(&loc->interp_elf_ex,
|
|
interpreter);
|
|
if (!interp_elf_phdata)
|
|
goto out_free_dentry;
|
|
|
|
/* Pass PT_LOPROC..PT_HIPROC headers to arch code */
|
|
elf_ppnt = interp_elf_phdata;
|
|
for (i = 0; i < loc->interp_elf_ex.e_phnum; i++, elf_ppnt++)
|
|
switch (elf_ppnt->p_type) {
|
|
case PT_LOPROC ... PT_HIPROC:
|
|
retval = arch_elf_pt_proc(&loc->interp_elf_ex,
|
|
elf_ppnt, interpreter,
|
|
true, &arch_state);
|
|
if (retval)
|
|
goto out_free_dentry;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Allow arch code to reject the ELF at this point, whilst it's
|
|
* still possible to return an error to the code that invoked
|
|
* the exec syscall.
|
|
*/
|
|
retval = arch_check_elf(elf_ex,
|
|
!!interpreter, &loc->interp_elf_ex,
|
|
&arch_state);
|
|
if (retval)
|
|
goto out_free_dentry;
|
|
|
|
/* Flush all traces of the currently running executable */
|
|
retval = flush_old_exec(bprm);
|
|
if (retval)
|
|
goto out_free_dentry;
|
|
|
|
/* Do this immediately, since STACK_TOP as used in setup_arg_pages
|
|
may depend on the personality. */
|
|
SET_PERSONALITY2(*elf_ex, &arch_state);
|
|
if (elf_read_implies_exec(*elf_ex, executable_stack))
|
|
current->personality |= READ_IMPLIES_EXEC;
|
|
|
|
if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
|
|
current->flags |= PF_RANDOMIZE;
|
|
|
|
setup_new_exec(bprm);
|
|
install_exec_creds(bprm);
|
|
|
|
/* Do this so that we can load the interpreter, if need be. We will
|
|
change some of these later */
|
|
retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
|
|
executable_stack);
|
|
if (retval < 0)
|
|
goto out_free_dentry;
|
|
|
|
elf_bss = 0;
|
|
elf_brk = 0;
|
|
|
|
start_code = ~0UL;
|
|
end_code = 0;
|
|
start_data = 0;
|
|
end_data = 0;
|
|
|
|
/* Now we do a little grungy work by mmapping the ELF image into
|
|
the correct location in memory. */
|
|
for(i = 0, elf_ppnt = elf_phdata;
|
|
i < elf_ex->e_phnum; i++, elf_ppnt++) {
|
|
int elf_prot, elf_flags;
|
|
unsigned long k, vaddr;
|
|
unsigned long total_size = 0;
|
|
|
|
if (elf_ppnt->p_type != PT_LOAD)
|
|
continue;
|
|
|
|
if (unlikely (elf_brk > elf_bss)) {
|
|
unsigned long nbyte;
|
|
|
|
/* There was a PT_LOAD segment with p_memsz > p_filesz
|
|
before this one. Map anonymous pages, if needed,
|
|
and clear the area. */
|
|
retval = set_brk(elf_bss + load_bias,
|
|
elf_brk + load_bias,
|
|
bss_prot);
|
|
if (retval)
|
|
goto out_free_dentry;
|
|
nbyte = ELF_PAGEOFFSET(elf_bss);
|
|
if (nbyte) {
|
|
nbyte = ELF_MIN_ALIGN - nbyte;
|
|
if (nbyte > elf_brk - elf_bss)
|
|
nbyte = elf_brk - elf_bss;
|
|
if (clear_user((void __user *)elf_bss +
|
|
load_bias, nbyte)) {
|
|
/*
|
|
* This bss-zeroing can fail if the ELF
|
|
* file specifies odd protections. So
|
|
* we don't check the return value
|
|
*/
|
|
}
|
|
}
|
|
}
|
|
|
|
elf_prot = make_prot(elf_ppnt->p_flags);
|
|
|
|
elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
|
|
|
|
vaddr = elf_ppnt->p_vaddr;
|
|
/*
|
|
* If we are loading ET_EXEC or we have already performed
|
|
* the ET_DYN load_addr calculations, proceed normally.
|
|
*/
|
|
if (elf_ex->e_type == ET_EXEC || load_addr_set) {
|
|
elf_flags |= MAP_FIXED;
|
|
} else if (elf_ex->e_type == ET_DYN) {
|
|
/*
|
|
* This logic is run once for the first LOAD Program
|
|
* Header for ET_DYN binaries to calculate the
|
|
* randomization (load_bias) for all the LOAD
|
|
* Program Headers, and to calculate the entire
|
|
* size of the ELF mapping (total_size). (Note that
|
|
* load_addr_set is set to true later once the
|
|
* initial mapping is performed.)
|
|
*
|
|
* There are effectively two types of ET_DYN
|
|
* binaries: programs (i.e. PIE: ET_DYN with INTERP)
|
|
* and loaders (ET_DYN without INTERP, since they
|
|
* _are_ the ELF interpreter). The loaders must
|
|
* be loaded away from programs since the program
|
|
* may otherwise collide with the loader (especially
|
|
* for ET_EXEC which does not have a randomized
|
|
* position). For example to handle invocations of
|
|
* "./ld.so someprog" to test out a new version of
|
|
* the loader, the subsequent program that the
|
|
* loader loads must avoid the loader itself, so
|
|
* they cannot share the same load range. Sufficient
|
|
* room for the brk must be allocated with the
|
|
* loader as well, since brk must be available with
|
|
* the loader.
|
|
*
|
|
* Therefore, programs are loaded offset from
|
|
* ELF_ET_DYN_BASE and loaders are loaded into the
|
|
* independently randomized mmap region (0 load_bias
|
|
* without MAP_FIXED).
|
|
*/
|
|
if (interpreter) {
|
|
load_bias = ELF_ET_DYN_BASE;
|
|
if (current->flags & PF_RANDOMIZE)
|
|
load_bias += arch_mmap_rnd();
|
|
elf_flags |= MAP_FIXED;
|
|
} else
|
|
load_bias = 0;
|
|
|
|
/*
|
|
* Since load_bias is used for all subsequent loading
|
|
* calculations, we must lower it by the first vaddr
|
|
* so that the remaining calculations based on the
|
|
* ELF vaddrs will be correctly offset. The result
|
|
* is then page aligned.
|
|
*/
|
|
load_bias = ELF_PAGESTART(load_bias - vaddr);
|
|
|
|
total_size = total_mapping_size(elf_phdata,
|
|
elf_ex->e_phnum);
|
|
if (!total_size) {
|
|
retval = -EINVAL;
|
|
goto out_free_dentry;
|
|
}
|
|
}
|
|
|
|
error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
|
|
elf_prot, elf_flags, total_size);
|
|
if (BAD_ADDR(error)) {
|
|
retval = IS_ERR((void *)error) ?
|
|
PTR_ERR((void*)error) : -EINVAL;
|
|
goto out_free_dentry;
|
|
}
|
|
|
|
if (!load_addr_set) {
|
|
load_addr_set = 1;
|
|
load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
|
|
if (elf_ex->e_type == ET_DYN) {
|
|
load_bias += error -
|
|
ELF_PAGESTART(load_bias + vaddr);
|
|
load_addr += load_bias;
|
|
reloc_func_desc = load_bias;
|
|
}
|
|
}
|
|
k = elf_ppnt->p_vaddr;
|
|
if ((elf_ppnt->p_flags & PF_X) && k < start_code)
|
|
start_code = k;
|
|
if (start_data < k)
|
|
start_data = k;
|
|
|
|
/*
|
|
* Check to see if the section's size will overflow the
|
|
* allowed task size. Note that p_filesz must always be
|
|
* <= p_memsz so it is only necessary to check p_memsz.
|
|
*/
|
|
if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
|
|
elf_ppnt->p_memsz > TASK_SIZE ||
|
|
TASK_SIZE - elf_ppnt->p_memsz < k) {
|
|
/* set_brk can never work. Avoid overflows. */
|
|
retval = -EINVAL;
|
|
goto out_free_dentry;
|
|
}
|
|
|
|
k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
|
|
|
|
if (k > elf_bss)
|
|
elf_bss = k;
|
|
if ((elf_ppnt->p_flags & PF_X) && end_code < k)
|
|
end_code = k;
|
|
if (end_data < k)
|
|
end_data = k;
|
|
k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
|
|
if (k > elf_brk) {
|
|
bss_prot = elf_prot;
|
|
elf_brk = k;
|
|
}
|
|
}
|
|
|
|
e_entry = elf_ex->e_entry + load_bias;
|
|
elf_bss += load_bias;
|
|
elf_brk += load_bias;
|
|
start_code += load_bias;
|
|
end_code += load_bias;
|
|
start_data += load_bias;
|
|
end_data += load_bias;
|
|
|
|
/* Calling set_brk effectively mmaps the pages that we need
|
|
* for the bss and break sections. We must do this before
|
|
* mapping in the interpreter, to make sure it doesn't wind
|
|
* up getting placed where the bss needs to go.
|
|
*/
|
|
retval = set_brk(elf_bss, elf_brk, bss_prot);
|
|
if (retval)
|
|
goto out_free_dentry;
|
|
if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
|
|
retval = -EFAULT; /* Nobody gets to see this, but.. */
|
|
goto out_free_dentry;
|
|
}
|
|
|
|
if (interpreter) {
|
|
elf_entry = load_elf_interp(&loc->interp_elf_ex,
|
|
interpreter,
|
|
load_bias, interp_elf_phdata);
|
|
if (!IS_ERR((void *)elf_entry)) {
|
|
/*
|
|
* load_elf_interp() returns relocation
|
|
* adjustment
|
|
*/
|
|
interp_load_addr = elf_entry;
|
|
elf_entry += loc->interp_elf_ex.e_entry;
|
|
}
|
|
if (BAD_ADDR(elf_entry)) {
|
|
retval = IS_ERR((void *)elf_entry) ?
|
|
(int)elf_entry : -EINVAL;
|
|
goto out_free_dentry;
|
|
}
|
|
reloc_func_desc = interp_load_addr;
|
|
|
|
allow_write_access(interpreter);
|
|
fput(interpreter);
|
|
} else {
|
|
elf_entry = e_entry;
|
|
if (BAD_ADDR(elf_entry)) {
|
|
retval = -EINVAL;
|
|
goto out_free_dentry;
|
|
}
|
|
}
|
|
|
|
kfree(interp_elf_phdata);
|
|
kfree(elf_phdata);
|
|
|
|
set_binfmt(&elf_format);
|
|
|
|
#ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
|
|
retval = arch_setup_additional_pages(bprm, !!interpreter);
|
|
if (retval < 0)
|
|
goto out;
|
|
#endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
|
|
|
|
retval = create_elf_tables(bprm, elf_ex,
|
|
load_addr, interp_load_addr, e_entry);
|
|
if (retval < 0)
|
|
goto out;
|
|
|
|
mm = current->mm;
|
|
mm->end_code = end_code;
|
|
mm->start_code = start_code;
|
|
mm->start_data = start_data;
|
|
mm->end_data = end_data;
|
|
mm->start_stack = bprm->p;
|
|
|
|
if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) {
|
|
/*
|
|
* For architectures with ELF randomization, when executing
|
|
* a loader directly (i.e. no interpreter listed in ELF
|
|
* headers), move the brk area out of the mmap region
|
|
* (since it grows up, and may collide early with the stack
|
|
* growing down), and into the unused ELF_ET_DYN_BASE region.
|
|
*/
|
|
if (IS_ENABLED(CONFIG_ARCH_HAS_ELF_RANDOMIZE) &&
|
|
elf_ex->e_type == ET_DYN && !interpreter) {
|
|
mm->brk = mm->start_brk = ELF_ET_DYN_BASE;
|
|
}
|
|
|
|
mm->brk = mm->start_brk = arch_randomize_brk(mm);
|
|
#ifdef compat_brk_randomized
|
|
current->brk_randomized = 1;
|
|
#endif
|
|
}
|
|
|
|
if (current->personality & MMAP_PAGE_ZERO) {
|
|
/* Why this, you ask??? Well SVr4 maps page 0 as read-only,
|
|
and some applications "depend" upon this behavior.
|
|
Since we do not have the power to recompile these, we
|
|
emulate the SVr4 behavior. Sigh. */
|
|
error = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
|
|
MAP_FIXED | MAP_PRIVATE, 0);
|
|
}
|
|
|
|
regs = current_pt_regs();
|
|
#ifdef ELF_PLAT_INIT
|
|
/*
|
|
* The ABI may specify that certain registers be set up in special
|
|
* ways (on i386 %edx is the address of a DT_FINI function, for
|
|
* example. In addition, it may also specify (eg, PowerPC64 ELF)
|
|
* that the e_entry field is the address of the function descriptor
|
|
* for the startup routine, rather than the address of the startup
|
|
* routine itself. This macro performs whatever initialization to
|
|
* the regs structure is required as well as any relocations to the
|
|
* function descriptor entries when executing dynamically links apps.
|
|
*/
|
|
ELF_PLAT_INIT(regs, reloc_func_desc);
|
|
#endif
|
|
|
|
finalize_exec(bprm);
|
|
start_thread(regs, elf_entry, bprm->p);
|
|
retval = 0;
|
|
out:
|
|
kfree(loc);
|
|
out_ret:
|
|
return retval;
|
|
|
|
/* error cleanup */
|
|
out_free_dentry:
|
|
kfree(interp_elf_phdata);
|
|
allow_write_access(interpreter);
|
|
if (interpreter)
|
|
fput(interpreter);
|
|
out_free_ph:
|
|
kfree(elf_phdata);
|
|
goto out;
|
|
}
|
|
|
|
#ifdef CONFIG_USELIB
|
|
/* This is really simpleminded and specialized - we are loading an
|
|
a.out library that is given an ELF header. */
|
|
static int load_elf_library(struct file *file)
|
|
{
|
|
struct elf_phdr *elf_phdata;
|
|
struct elf_phdr *eppnt;
|
|
unsigned long elf_bss, bss, len;
|
|
int retval, error, i, j;
|
|
struct elfhdr elf_ex;
|
|
|
|
error = -ENOEXEC;
|
|
retval = elf_read(file, &elf_ex, sizeof(elf_ex), 0);
|
|
if (retval < 0)
|
|
goto out;
|
|
|
|
if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
|
|
goto out;
|
|
|
|
/* First of all, some simple consistency checks */
|
|
if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
|
|
!elf_check_arch(&elf_ex) || !file->f_op->mmap)
|
|
goto out;
|
|
if (elf_check_fdpic(&elf_ex))
|
|
goto out;
|
|
|
|
/* Now read in all of the header information */
|
|
|
|
j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
|
|
/* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
|
|
|
|
error = -ENOMEM;
|
|
elf_phdata = kmalloc(j, GFP_KERNEL);
|
|
if (!elf_phdata)
|
|
goto out;
|
|
|
|
eppnt = elf_phdata;
|
|
error = -ENOEXEC;
|
|
retval = elf_read(file, eppnt, j, elf_ex.e_phoff);
|
|
if (retval < 0)
|
|
goto out_free_ph;
|
|
|
|
for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
|
|
if ((eppnt + i)->p_type == PT_LOAD)
|
|
j++;
|
|
if (j != 1)
|
|
goto out_free_ph;
|
|
|
|
while (eppnt->p_type != PT_LOAD)
|
|
eppnt++;
|
|
|
|
/* Now use mmap to map the library into memory. */
|
|
error = vm_mmap(file,
|
|
ELF_PAGESTART(eppnt->p_vaddr),
|
|
(eppnt->p_filesz +
|
|
ELF_PAGEOFFSET(eppnt->p_vaddr)),
|
|
PROT_READ | PROT_WRITE | PROT_EXEC,
|
|
MAP_FIXED_NOREPLACE | MAP_PRIVATE | MAP_DENYWRITE,
|
|
(eppnt->p_offset -
|
|
ELF_PAGEOFFSET(eppnt->p_vaddr)));
|
|
if (error != ELF_PAGESTART(eppnt->p_vaddr))
|
|
goto out_free_ph;
|
|
|
|
elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
|
|
if (padzero(elf_bss)) {
|
|
error = -EFAULT;
|
|
goto out_free_ph;
|
|
}
|
|
|
|
len = ELF_PAGEALIGN(eppnt->p_filesz + eppnt->p_vaddr);
|
|
bss = ELF_PAGEALIGN(eppnt->p_memsz + eppnt->p_vaddr);
|
|
if (bss > len) {
|
|
error = vm_brk(len, bss - len);
|
|
if (error)
|
|
goto out_free_ph;
|
|
}
|
|
error = 0;
|
|
|
|
out_free_ph:
|
|
kfree(elf_phdata);
|
|
out:
|
|
return error;
|
|
}
|
|
#endif /* #ifdef CONFIG_USELIB */
|
|
|
|
#ifdef CONFIG_ELF_CORE
|
|
/*
|
|
* ELF core dumper
|
|
*
|
|
* Modelled on fs/exec.c:aout_core_dump()
|
|
* Jeremy Fitzhardinge <jeremy@sw.oz.au>
|
|
*/
|
|
|
|
/*
|
|
* The purpose of always_dump_vma() is to make sure that special kernel mappings
|
|
* that are useful for post-mortem analysis are included in every core dump.
|
|
* In that way we ensure that the core dump is fully interpretable later
|
|
* without matching up the same kernel and hardware config to see what PC values
|
|
* meant. These special mappings include - vDSO, vsyscall, and other
|
|
* architecture specific mappings
|
|
*/
|
|
static bool always_dump_vma(struct vm_area_struct *vma)
|
|
{
|
|
/* Any vsyscall mappings? */
|
|
if (vma == get_gate_vma(vma->vm_mm))
|
|
return true;
|
|
|
|
/*
|
|
* Assume that all vmas with a .name op should always be dumped.
|
|
* If this changes, a new vm_ops field can easily be added.
|
|
*/
|
|
if (vma->vm_ops && vma->vm_ops->name && vma->vm_ops->name(vma))
|
|
return true;
|
|
|
|
/*
|
|
* arch_vma_name() returns non-NULL for special architecture mappings,
|
|
* such as vDSO sections.
|
|
*/
|
|
if (arch_vma_name(vma))
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Decide what to dump of a segment, part, all or none.
|
|
*/
|
|
static unsigned long vma_dump_size(struct vm_area_struct *vma,
|
|
unsigned long mm_flags)
|
|
{
|
|
#define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type))
|
|
|
|
/* always dump the vdso and vsyscall sections */
|
|
if (always_dump_vma(vma))
|
|
goto whole;
|
|
|
|
if (vma->vm_flags & VM_DONTDUMP)
|
|
return 0;
|
|
|
|
/* support for DAX */
|
|
if (vma_is_dax(vma)) {
|
|
if ((vma->vm_flags & VM_SHARED) && FILTER(DAX_SHARED))
|
|
goto whole;
|
|
if (!(vma->vm_flags & VM_SHARED) && FILTER(DAX_PRIVATE))
|
|
goto whole;
|
|
return 0;
|
|
}
|
|
|
|
/* Hugetlb memory check */
|
|
if (vma->vm_flags & VM_HUGETLB) {
|
|
if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
|
|
goto whole;
|
|
if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
|
|
goto whole;
|
|
return 0;
|
|
}
|
|
|
|
/* Do not dump I/O mapped devices or special mappings */
|
|
if (vma->vm_flags & VM_IO)
|
|
return 0;
|
|
|
|
/* By default, dump shared memory if mapped from an anonymous file. */
|
|
if (vma->vm_flags & VM_SHARED) {
|
|
if (file_inode(vma->vm_file)->i_nlink == 0 ?
|
|
FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
|
|
goto whole;
|
|
return 0;
|
|
}
|
|
|
|
/* Dump segments that have been written to. */
|
|
if (vma->anon_vma && FILTER(ANON_PRIVATE))
|
|
goto whole;
|
|
if (vma->vm_file == NULL)
|
|
return 0;
|
|
|
|
if (FILTER(MAPPED_PRIVATE))
|
|
goto whole;
|
|
|
|
/*
|
|
* If this looks like the beginning of a DSO or executable mapping,
|
|
* check for an ELF header. If we find one, dump the first page to
|
|
* aid in determining what was mapped here.
|
|
*/
|
|
if (FILTER(ELF_HEADERS) &&
|
|
vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
|
|
u32 __user *header = (u32 __user *) vma->vm_start;
|
|
u32 word;
|
|
mm_segment_t fs = get_fs();
|
|
/*
|
|
* Doing it this way gets the constant folded by GCC.
|
|
*/
|
|
union {
|
|
u32 cmp;
|
|
char elfmag[SELFMAG];
|
|
} magic;
|
|
BUILD_BUG_ON(SELFMAG != sizeof word);
|
|
magic.elfmag[EI_MAG0] = ELFMAG0;
|
|
magic.elfmag[EI_MAG1] = ELFMAG1;
|
|
magic.elfmag[EI_MAG2] = ELFMAG2;
|
|
magic.elfmag[EI_MAG3] = ELFMAG3;
|
|
/*
|
|
* Switch to the user "segment" for get_user(),
|
|
* then put back what elf_core_dump() had in place.
|
|
*/
|
|
set_fs(USER_DS);
|
|
if (unlikely(get_user(word, header)))
|
|
word = 0;
|
|
set_fs(fs);
|
|
if (word == magic.cmp)
|
|
return PAGE_SIZE;
|
|
}
|
|
|
|
#undef FILTER
|
|
|
|
return 0;
|
|
|
|
whole:
|
|
return vma->vm_end - vma->vm_start;
|
|
}
|
|
|
|
/* An ELF note in memory */
|
|
struct memelfnote
|
|
{
|
|
const char *name;
|
|
int type;
|
|
unsigned int datasz;
|
|
void *data;
|
|
};
|
|
|
|
static int notesize(struct memelfnote *en)
|
|
{
|
|
int sz;
|
|
|
|
sz = sizeof(struct elf_note);
|
|
sz += roundup(strlen(en->name) + 1, 4);
|
|
sz += roundup(en->datasz, 4);
|
|
|
|
return sz;
|
|
}
|
|
|
|
static int writenote(struct memelfnote *men, struct coredump_params *cprm)
|
|
{
|
|
struct elf_note en;
|
|
en.n_namesz = strlen(men->name) + 1;
|
|
en.n_descsz = men->datasz;
|
|
en.n_type = men->type;
|
|
|
|
return dump_emit(cprm, &en, sizeof(en)) &&
|
|
dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
|
|
dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
|
|
}
|
|
|
|
static void fill_elf_header(struct elfhdr *elf, int segs,
|
|
u16 machine, u32 flags)
|
|
{
|
|
memset(elf, 0, sizeof(*elf));
|
|
|
|
memcpy(elf->e_ident, ELFMAG, SELFMAG);
|
|
elf->e_ident[EI_CLASS] = ELF_CLASS;
|
|
elf->e_ident[EI_DATA] = ELF_DATA;
|
|
elf->e_ident[EI_VERSION] = EV_CURRENT;
|
|
elf->e_ident[EI_OSABI] = ELF_OSABI;
|
|
|
|
elf->e_type = ET_CORE;
|
|
elf->e_machine = machine;
|
|
elf->e_version = EV_CURRENT;
|
|
elf->e_phoff = sizeof(struct elfhdr);
|
|
elf->e_flags = flags;
|
|
elf->e_ehsize = sizeof(struct elfhdr);
|
|
elf->e_phentsize = sizeof(struct elf_phdr);
|
|
elf->e_phnum = segs;
|
|
}
|
|
|
|
static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
|
|
{
|
|
phdr->p_type = PT_NOTE;
|
|
phdr->p_offset = offset;
|
|
phdr->p_vaddr = 0;
|
|
phdr->p_paddr = 0;
|
|
phdr->p_filesz = sz;
|
|
phdr->p_memsz = 0;
|
|
phdr->p_flags = 0;
|
|
phdr->p_align = 0;
|
|
}
|
|
|
|
static void fill_note(struct memelfnote *note, const char *name, int type,
|
|
unsigned int sz, void *data)
|
|
{
|
|
note->name = name;
|
|
note->type = type;
|
|
note->datasz = sz;
|
|
note->data = data;
|
|
}
|
|
|
|
/*
|
|
* fill up all the fields in prstatus from the given task struct, except
|
|
* registers which need to be filled up separately.
|
|
*/
|
|
static void fill_prstatus(struct elf_prstatus *prstatus,
|
|
struct task_struct *p, long signr)
|
|
{
|
|
prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
|
|
prstatus->pr_sigpend = p->pending.signal.sig[0];
|
|
prstatus->pr_sighold = p->blocked.sig[0];
|
|
rcu_read_lock();
|
|
prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
|
|
rcu_read_unlock();
|
|
prstatus->pr_pid = task_pid_vnr(p);
|
|
prstatus->pr_pgrp = task_pgrp_vnr(p);
|
|
prstatus->pr_sid = task_session_vnr(p);
|
|
if (thread_group_leader(p)) {
|
|
struct task_cputime cputime;
|
|
|
|
/*
|
|
* This is the record for the group leader. It shows the
|
|
* group-wide total, not its individual thread total.
|
|
*/
|
|
thread_group_cputime(p, &cputime);
|
|
prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime);
|
|
prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime);
|
|
} else {
|
|
u64 utime, stime;
|
|
|
|
task_cputime(p, &utime, &stime);
|
|
prstatus->pr_utime = ns_to_kernel_old_timeval(utime);
|
|
prstatus->pr_stime = ns_to_kernel_old_timeval(stime);
|
|
}
|
|
|
|
prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime);
|
|
prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime);
|
|
}
|
|
|
|
static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
|
|
struct mm_struct *mm)
|
|
{
|
|
const struct cred *cred;
|
|
unsigned int i, len;
|
|
|
|
/* first copy the parameters from user space */
|
|
memset(psinfo, 0, sizeof(struct elf_prpsinfo));
|
|
|
|
len = mm->arg_end - mm->arg_start;
|
|
if (len >= ELF_PRARGSZ)
|
|
len = ELF_PRARGSZ-1;
|
|
if (copy_from_user(&psinfo->pr_psargs,
|
|
(const char __user *)mm->arg_start, len))
|
|
return -EFAULT;
|
|
for(i = 0; i < len; i++)
|
|
if (psinfo->pr_psargs[i] == 0)
|
|
psinfo->pr_psargs[i] = ' ';
|
|
psinfo->pr_psargs[len] = 0;
|
|
|
|
rcu_read_lock();
|
|
psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
|
|
rcu_read_unlock();
|
|
psinfo->pr_pid = task_pid_vnr(p);
|
|
psinfo->pr_pgrp = task_pgrp_vnr(p);
|
|
psinfo->pr_sid = task_session_vnr(p);
|
|
|
|
i = p->state ? ffz(~p->state) + 1 : 0;
|
|
psinfo->pr_state = i;
|
|
psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
|
|
psinfo->pr_zomb = psinfo->pr_sname == 'Z';
|
|
psinfo->pr_nice = task_nice(p);
|
|
psinfo->pr_flag = p->flags;
|
|
rcu_read_lock();
|
|
cred = __task_cred(p);
|
|
SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
|
|
SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
|
|
rcu_read_unlock();
|
|
strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
|
|
{
|
|
elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
|
|
int i = 0;
|
|
do
|
|
i += 2;
|
|
while (auxv[i - 2] != AT_NULL);
|
|
fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
|
|
}
|
|
|
|
static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata,
|
|
const kernel_siginfo_t *siginfo)
|
|
{
|
|
mm_segment_t old_fs = get_fs();
|
|
set_fs(KERNEL_DS);
|
|
copy_siginfo_to_user((user_siginfo_t __user *) csigdata, siginfo);
|
|
set_fs(old_fs);
|
|
fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata);
|
|
}
|
|
|
|
#define MAX_FILE_NOTE_SIZE (4*1024*1024)
|
|
/*
|
|
* Format of NT_FILE note:
|
|
*
|
|
* long count -- how many files are mapped
|
|
* long page_size -- units for file_ofs
|
|
* array of [COUNT] elements of
|
|
* long start
|
|
* long end
|
|
* long file_ofs
|
|
* followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL...
|
|
*/
|
|
static int fill_files_note(struct memelfnote *note)
|
|
{
|
|
struct mm_struct *mm = current->mm;
|
|
struct vm_area_struct *vma;
|
|
unsigned count, size, names_ofs, remaining, n;
|
|
user_long_t *data;
|
|
user_long_t *start_end_ofs;
|
|
char *name_base, *name_curpos;
|
|
|
|
/* *Estimated* file count and total data size needed */
|
|
count = mm->map_count;
|
|
if (count > UINT_MAX / 64)
|
|
return -EINVAL;
|
|
size = count * 64;
|
|
|
|
names_ofs = (2 + 3 * count) * sizeof(data[0]);
|
|
alloc:
|
|
if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */
|
|
return -EINVAL;
|
|
size = round_up(size, PAGE_SIZE);
|
|
/*
|
|
* "size" can be 0 here legitimately.
|
|
* Let it ENOMEM and omit NT_FILE section which will be empty anyway.
|
|
*/
|
|
data = kvmalloc(size, GFP_KERNEL);
|
|
if (ZERO_OR_NULL_PTR(data))
|
|
return -ENOMEM;
|
|
|
|
start_end_ofs = data + 2;
|
|
name_base = name_curpos = ((char *)data) + names_ofs;
|
|
remaining = size - names_ofs;
|
|
count = 0;
|
|
for (vma = mm->mmap; vma != NULL; vma = vma->vm_next) {
|
|
struct file *file;
|
|
const char *filename;
|
|
|
|
file = vma->vm_file;
|
|
if (!file)
|
|
continue;
|
|
filename = file_path(file, name_curpos, remaining);
|
|
if (IS_ERR(filename)) {
|
|
if (PTR_ERR(filename) == -ENAMETOOLONG) {
|
|
kvfree(data);
|
|
size = size * 5 / 4;
|
|
goto alloc;
|
|
}
|
|
continue;
|
|
}
|
|
|
|
/* file_path() fills at the end, move name down */
|
|
/* n = strlen(filename) + 1: */
|
|
n = (name_curpos + remaining) - filename;
|
|
remaining = filename - name_curpos;
|
|
memmove(name_curpos, filename, n);
|
|
name_curpos += n;
|
|
|
|
*start_end_ofs++ = vma->vm_start;
|
|
*start_end_ofs++ = vma->vm_end;
|
|
*start_end_ofs++ = vma->vm_pgoff;
|
|
count++;
|
|
}
|
|
|
|
/* Now we know exact count of files, can store it */
|
|
data[0] = count;
|
|
data[1] = PAGE_SIZE;
|
|
/*
|
|
* Count usually is less than mm->map_count,
|
|
* we need to move filenames down.
|
|
*/
|
|
n = mm->map_count - count;
|
|
if (n != 0) {
|
|
unsigned shift_bytes = n * 3 * sizeof(data[0]);
|
|
memmove(name_base - shift_bytes, name_base,
|
|
name_curpos - name_base);
|
|
name_curpos -= shift_bytes;
|
|
}
|
|
|
|
size = name_curpos - (char *)data;
|
|
fill_note(note, "CORE", NT_FILE, size, data);
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CORE_DUMP_USE_REGSET
|
|
#include <linux/regset.h>
|
|
|
|
struct elf_thread_core_info {
|
|
struct elf_thread_core_info *next;
|
|
struct task_struct *task;
|
|
struct elf_prstatus prstatus;
|
|
struct memelfnote notes[0];
|
|
};
|
|
|
|
struct elf_note_info {
|
|
struct elf_thread_core_info *thread;
|
|
struct memelfnote psinfo;
|
|
struct memelfnote signote;
|
|
struct memelfnote auxv;
|
|
struct memelfnote files;
|
|
user_siginfo_t csigdata;
|
|
size_t size;
|
|
int thread_notes;
|
|
};
|
|
|
|
/*
|
|
* When a regset has a writeback hook, we call it on each thread before
|
|
* dumping user memory. On register window machines, this makes sure the
|
|
* user memory backing the register data is up to date before we read it.
|
|
*/
|
|
static void do_thread_regset_writeback(struct task_struct *task,
|
|
const struct user_regset *regset)
|
|
{
|
|
if (regset->writeback)
|
|
regset->writeback(task, regset, 1);
|
|
}
|
|
|
|
#ifndef PRSTATUS_SIZE
|
|
#define PRSTATUS_SIZE(S, R) sizeof(S)
|
|
#endif
|
|
|
|
#ifndef SET_PR_FPVALID
|
|
#define SET_PR_FPVALID(S, V, R) ((S)->pr_fpvalid = (V))
|
|
#endif
|
|
|
|
static int fill_thread_core_info(struct elf_thread_core_info *t,
|
|
const struct user_regset_view *view,
|
|
long signr, size_t *total)
|
|
{
|
|
unsigned int i;
|
|
unsigned int regset0_size = regset_size(t->task, &view->regsets[0]);
|
|
|
|
/*
|
|
* NT_PRSTATUS is the one special case, because the regset data
|
|
* goes into the pr_reg field inside the note contents, rather
|
|
* than being the whole note contents. We fill the reset in here.
|
|
* We assume that regset 0 is NT_PRSTATUS.
|
|
*/
|
|
fill_prstatus(&t->prstatus, t->task, signr);
|
|
(void) view->regsets[0].get(t->task, &view->regsets[0], 0, regset0_size,
|
|
&t->prstatus.pr_reg, NULL);
|
|
|
|
fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
|
|
PRSTATUS_SIZE(t->prstatus, regset0_size), &t->prstatus);
|
|
*total += notesize(&t->notes[0]);
|
|
|
|
do_thread_regset_writeback(t->task, &view->regsets[0]);
|
|
|
|
/*
|
|
* Each other regset might generate a note too. For each regset
|
|
* that has no core_note_type or is inactive, we leave t->notes[i]
|
|
* all zero and we'll know to skip writing it later.
|
|
*/
|
|
for (i = 1; i < view->n; ++i) {
|
|
const struct user_regset *regset = &view->regsets[i];
|
|
do_thread_regset_writeback(t->task, regset);
|
|
if (regset->core_note_type && regset->get &&
|
|
(!regset->active || regset->active(t->task, regset) > 0)) {
|
|
int ret;
|
|
size_t size = regset_size(t->task, regset);
|
|
void *data = kmalloc(size, GFP_KERNEL);
|
|
if (unlikely(!data))
|
|
return 0;
|
|
ret = regset->get(t->task, regset,
|
|
0, size, data, NULL);
|
|
if (unlikely(ret))
|
|
kfree(data);
|
|
else {
|
|
if (regset->core_note_type != NT_PRFPREG)
|
|
fill_note(&t->notes[i], "LINUX",
|
|
regset->core_note_type,
|
|
size, data);
|
|
else {
|
|
SET_PR_FPVALID(&t->prstatus,
|
|
1, regset0_size);
|
|
fill_note(&t->notes[i], "CORE",
|
|
NT_PRFPREG, size, data);
|
|
}
|
|
*total += notesize(&t->notes[i]);
|
|
}
|
|
}
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
static int fill_note_info(struct elfhdr *elf, int phdrs,
|
|
struct elf_note_info *info,
|
|
const kernel_siginfo_t *siginfo, struct pt_regs *regs)
|
|
{
|
|
struct task_struct *dump_task = current;
|
|
const struct user_regset_view *view = task_user_regset_view(dump_task);
|
|
struct elf_thread_core_info *t;
|
|
struct elf_prpsinfo *psinfo;
|
|
struct core_thread *ct;
|
|
unsigned int i;
|
|
|
|
info->size = 0;
|
|
info->thread = NULL;
|
|
|
|
psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
|
|
if (psinfo == NULL) {
|
|
info->psinfo.data = NULL; /* So we don't free this wrongly */
|
|
return 0;
|
|
}
|
|
|
|
fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
|
|
|
|
/*
|
|
* Figure out how many notes we're going to need for each thread.
|
|
*/
|
|
info->thread_notes = 0;
|
|
for (i = 0; i < view->n; ++i)
|
|
if (view->regsets[i].core_note_type != 0)
|
|
++info->thread_notes;
|
|
|
|
/*
|
|
* Sanity check. We rely on regset 0 being in NT_PRSTATUS,
|
|
* since it is our one special case.
|
|
*/
|
|
if (unlikely(info->thread_notes == 0) ||
|
|
unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
|
|
WARN_ON(1);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Initialize the ELF file header.
|
|
*/
|
|
fill_elf_header(elf, phdrs,
|
|
view->e_machine, view->e_flags);
|
|
|
|
/*
|
|
* Allocate a structure for each thread.
|
|
*/
|
|
for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
|
|
t = kzalloc(offsetof(struct elf_thread_core_info,
|
|
notes[info->thread_notes]),
|
|
GFP_KERNEL);
|
|
if (unlikely(!t))
|
|
return 0;
|
|
|
|
t->task = ct->task;
|
|
if (ct->task == dump_task || !info->thread) {
|
|
t->next = info->thread;
|
|
info->thread = t;
|
|
} else {
|
|
/*
|
|
* Make sure to keep the original task at
|
|
* the head of the list.
|
|
*/
|
|
t->next = info->thread->next;
|
|
info->thread->next = t;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Now fill in each thread's information.
|
|
*/
|
|
for (t = info->thread; t != NULL; t = t->next)
|
|
if (!fill_thread_core_info(t, view, siginfo->si_signo, &info->size))
|
|
return 0;
|
|
|
|
/*
|
|
* Fill in the two process-wide notes.
|
|
*/
|
|
fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
|
|
info->size += notesize(&info->psinfo);
|
|
|
|
fill_siginfo_note(&info->signote, &info->csigdata, siginfo);
|
|
info->size += notesize(&info->signote);
|
|
|
|
fill_auxv_note(&info->auxv, current->mm);
|
|
info->size += notesize(&info->auxv);
|
|
|
|
if (fill_files_note(&info->files) == 0)
|
|
info->size += notesize(&info->files);
|
|
|
|
return 1;
|
|
}
|
|
|
|
static size_t get_note_info_size(struct elf_note_info *info)
|
|
{
|
|
return info->size;
|
|
}
|
|
|
|
/*
|
|
* Write all the notes for each thread. When writing the first thread, the
|
|
* process-wide notes are interleaved after the first thread-specific note.
|
|
*/
|
|
static int write_note_info(struct elf_note_info *info,
|
|
struct coredump_params *cprm)
|
|
{
|
|
bool first = true;
|
|
struct elf_thread_core_info *t = info->thread;
|
|
|
|
do {
|
|
int i;
|
|
|
|
if (!writenote(&t->notes[0], cprm))
|
|
return 0;
|
|
|
|
if (first && !writenote(&info->psinfo, cprm))
|
|
return 0;
|
|
if (first && !writenote(&info->signote, cprm))
|
|
return 0;
|
|
if (first && !writenote(&info->auxv, cprm))
|
|
return 0;
|
|
if (first && info->files.data &&
|
|
!writenote(&info->files, cprm))
|
|
return 0;
|
|
|
|
for (i = 1; i < info->thread_notes; ++i)
|
|
if (t->notes[i].data &&
|
|
!writenote(&t->notes[i], cprm))
|
|
return 0;
|
|
|
|
first = false;
|
|
t = t->next;
|
|
} while (t);
|
|
|
|
return 1;
|
|
}
|
|
|
|
static void free_note_info(struct elf_note_info *info)
|
|
{
|
|
struct elf_thread_core_info *threads = info->thread;
|
|
while (threads) {
|
|
unsigned int i;
|
|
struct elf_thread_core_info *t = threads;
|
|
threads = t->next;
|
|
WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
|
|
for (i = 1; i < info->thread_notes; ++i)
|
|
kfree(t->notes[i].data);
|
|
kfree(t);
|
|
}
|
|
kfree(info->psinfo.data);
|
|
kvfree(info->files.data);
|
|
}
|
|
|
|
#else
|
|
|
|
/* Here is the structure in which status of each thread is captured. */
|
|
struct elf_thread_status
|
|
{
|
|
struct list_head list;
|
|
struct elf_prstatus prstatus; /* NT_PRSTATUS */
|
|
elf_fpregset_t fpu; /* NT_PRFPREG */
|
|
struct task_struct *thread;
|
|
#ifdef ELF_CORE_COPY_XFPREGS
|
|
elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
|
|
#endif
|
|
struct memelfnote notes[3];
|
|
int num_notes;
|
|
};
|
|
|
|
/*
|
|
* In order to add the specific thread information for the elf file format,
|
|
* we need to keep a linked list of every threads pr_status and then create
|
|
* a single section for them in the final core file.
|
|
*/
|
|
static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
|
|
{
|
|
int sz = 0;
|
|
struct task_struct *p = t->thread;
|
|
t->num_notes = 0;
|
|
|
|
fill_prstatus(&t->prstatus, p, signr);
|
|
elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
|
|
|
|
fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
|
|
&(t->prstatus));
|
|
t->num_notes++;
|
|
sz += notesize(&t->notes[0]);
|
|
|
|
if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
|
|
&t->fpu))) {
|
|
fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
|
|
&(t->fpu));
|
|
t->num_notes++;
|
|
sz += notesize(&t->notes[1]);
|
|
}
|
|
|
|
#ifdef ELF_CORE_COPY_XFPREGS
|
|
if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
|
|
fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
|
|
sizeof(t->xfpu), &t->xfpu);
|
|
t->num_notes++;
|
|
sz += notesize(&t->notes[2]);
|
|
}
|
|
#endif
|
|
return sz;
|
|
}
|
|
|
|
struct elf_note_info {
|
|
struct memelfnote *notes;
|
|
struct memelfnote *notes_files;
|
|
struct elf_prstatus *prstatus; /* NT_PRSTATUS */
|
|
struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */
|
|
struct list_head thread_list;
|
|
elf_fpregset_t *fpu;
|
|
#ifdef ELF_CORE_COPY_XFPREGS
|
|
elf_fpxregset_t *xfpu;
|
|
#endif
|
|
user_siginfo_t csigdata;
|
|
int thread_status_size;
|
|
int numnote;
|
|
};
|
|
|
|
static int elf_note_info_init(struct elf_note_info *info)
|
|
{
|
|
memset(info, 0, sizeof(*info));
|
|
INIT_LIST_HEAD(&info->thread_list);
|
|
|
|
/* Allocate space for ELF notes */
|
|
info->notes = kmalloc_array(8, sizeof(struct memelfnote), GFP_KERNEL);
|
|
if (!info->notes)
|
|
return 0;
|
|
info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
|
|
if (!info->psinfo)
|
|
return 0;
|
|
info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
|
|
if (!info->prstatus)
|
|
return 0;
|
|
info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
|
|
if (!info->fpu)
|
|
return 0;
|
|
#ifdef ELF_CORE_COPY_XFPREGS
|
|
info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
|
|
if (!info->xfpu)
|
|
return 0;
|
|
#endif
|
|
return 1;
|
|
}
|
|
|
|
static int fill_note_info(struct elfhdr *elf, int phdrs,
|
|
struct elf_note_info *info,
|
|
const kernel_siginfo_t *siginfo, struct pt_regs *regs)
|
|
{
|
|
struct core_thread *ct;
|
|
struct elf_thread_status *ets;
|
|
|
|
if (!elf_note_info_init(info))
|
|
return 0;
|
|
|
|
for (ct = current->mm->core_state->dumper.next;
|
|
ct; ct = ct->next) {
|
|
ets = kzalloc(sizeof(*ets), GFP_KERNEL);
|
|
if (!ets)
|
|
return 0;
|
|
|
|
ets->thread = ct->task;
|
|
list_add(&ets->list, &info->thread_list);
|
|
}
|
|
|
|
list_for_each_entry(ets, &info->thread_list, list) {
|
|
int sz;
|
|
|
|
sz = elf_dump_thread_status(siginfo->si_signo, ets);
|
|
info->thread_status_size += sz;
|
|
}
|
|
/* now collect the dump for the current */
|
|
memset(info->prstatus, 0, sizeof(*info->prstatus));
|
|
fill_prstatus(info->prstatus, current, siginfo->si_signo);
|
|
elf_core_copy_regs(&info->prstatus->pr_reg, regs);
|
|
|
|
/* Set up header */
|
|
fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS);
|
|
|
|
/*
|
|
* Set up the notes in similar form to SVR4 core dumps made
|
|
* with info from their /proc.
|
|
*/
|
|
|
|
fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
|
|
sizeof(*info->prstatus), info->prstatus);
|
|
fill_psinfo(info->psinfo, current->group_leader, current->mm);
|
|
fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
|
|
sizeof(*info->psinfo), info->psinfo);
|
|
|
|
fill_siginfo_note(info->notes + 2, &info->csigdata, siginfo);
|
|
fill_auxv_note(info->notes + 3, current->mm);
|
|
info->numnote = 4;
|
|
|
|
if (fill_files_note(info->notes + info->numnote) == 0) {
|
|
info->notes_files = info->notes + info->numnote;
|
|
info->numnote++;
|
|
}
|
|
|
|
/* Try to dump the FPU. */
|
|
info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
|
|
info->fpu);
|
|
if (info->prstatus->pr_fpvalid)
|
|
fill_note(info->notes + info->numnote++,
|
|
"CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
|
|
#ifdef ELF_CORE_COPY_XFPREGS
|
|
if (elf_core_copy_task_xfpregs(current, info->xfpu))
|
|
fill_note(info->notes + info->numnote++,
|
|
"LINUX", ELF_CORE_XFPREG_TYPE,
|
|
sizeof(*info->xfpu), info->xfpu);
|
|
#endif
|
|
|
|
return 1;
|
|
}
|
|
|
|
static size_t get_note_info_size(struct elf_note_info *info)
|
|
{
|
|
int sz = 0;
|
|
int i;
|
|
|
|
for (i = 0; i < info->numnote; i++)
|
|
sz += notesize(info->notes + i);
|
|
|
|
sz += info->thread_status_size;
|
|
|
|
return sz;
|
|
}
|
|
|
|
static int write_note_info(struct elf_note_info *info,
|
|
struct coredump_params *cprm)
|
|
{
|
|
struct elf_thread_status *ets;
|
|
int i;
|
|
|
|
for (i = 0; i < info->numnote; i++)
|
|
if (!writenote(info->notes + i, cprm))
|
|
return 0;
|
|
|
|
/* write out the thread status notes section */
|
|
list_for_each_entry(ets, &info->thread_list, list) {
|
|
for (i = 0; i < ets->num_notes; i++)
|
|
if (!writenote(&ets->notes[i], cprm))
|
|
return 0;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
static void free_note_info(struct elf_note_info *info)
|
|
{
|
|
while (!list_empty(&info->thread_list)) {
|
|
struct list_head *tmp = info->thread_list.next;
|
|
list_del(tmp);
|
|
kfree(list_entry(tmp, struct elf_thread_status, list));
|
|
}
|
|
|
|
/* Free data possibly allocated by fill_files_note(): */
|
|
if (info->notes_files)
|
|
kvfree(info->notes_files->data);
|
|
|
|
kfree(info->prstatus);
|
|
kfree(info->psinfo);
|
|
kfree(info->notes);
|
|
kfree(info->fpu);
|
|
#ifdef ELF_CORE_COPY_XFPREGS
|
|
kfree(info->xfpu);
|
|
#endif
|
|
}
|
|
|
|
#endif
|
|
|
|
static struct vm_area_struct *first_vma(struct task_struct *tsk,
|
|
struct vm_area_struct *gate_vma)
|
|
{
|
|
struct vm_area_struct *ret = tsk->mm->mmap;
|
|
|
|
if (ret)
|
|
return ret;
|
|
return gate_vma;
|
|
}
|
|
/*
|
|
* Helper function for iterating across a vma list. It ensures that the caller
|
|
* will visit `gate_vma' prior to terminating the search.
|
|
*/
|
|
static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
|
|
struct vm_area_struct *gate_vma)
|
|
{
|
|
struct vm_area_struct *ret;
|
|
|
|
ret = this_vma->vm_next;
|
|
if (ret)
|
|
return ret;
|
|
if (this_vma == gate_vma)
|
|
return NULL;
|
|
return gate_vma;
|
|
}
|
|
|
|
static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
|
|
elf_addr_t e_shoff, int segs)
|
|
{
|
|
elf->e_shoff = e_shoff;
|
|
elf->e_shentsize = sizeof(*shdr4extnum);
|
|
elf->e_shnum = 1;
|
|
elf->e_shstrndx = SHN_UNDEF;
|
|
|
|
memset(shdr4extnum, 0, sizeof(*shdr4extnum));
|
|
|
|
shdr4extnum->sh_type = SHT_NULL;
|
|
shdr4extnum->sh_size = elf->e_shnum;
|
|
shdr4extnum->sh_link = elf->e_shstrndx;
|
|
shdr4extnum->sh_info = segs;
|
|
}
|
|
|
|
/*
|
|
* Actual dumper
|
|
*
|
|
* This is a two-pass process; first we find the offsets of the bits,
|
|
* and then they are actually written out. If we run out of core limit
|
|
* we just truncate.
|
|
*/
|
|
static int elf_core_dump(struct coredump_params *cprm)
|
|
{
|
|
int has_dumped = 0;
|
|
mm_segment_t fs;
|
|
int segs, i;
|
|
size_t vma_data_size = 0;
|
|
struct vm_area_struct *vma, *gate_vma;
|
|
struct elfhdr elf;
|
|
loff_t offset = 0, dataoff;
|
|
struct elf_note_info info = { };
|
|
struct elf_phdr *phdr4note = NULL;
|
|
struct elf_shdr *shdr4extnum = NULL;
|
|
Elf_Half e_phnum;
|
|
elf_addr_t e_shoff;
|
|
elf_addr_t *vma_filesz = NULL;
|
|
|
|
/*
|
|
* We no longer stop all VM operations.
|
|
*
|
|
* This is because those proceses that could possibly change map_count
|
|
* or the mmap / vma pages are now blocked in do_exit on current
|
|
* finishing this core dump.
|
|
*
|
|
* Only ptrace can touch these memory addresses, but it doesn't change
|
|
* the map_count or the pages allocated. So no possibility of crashing
|
|
* exists while dumping the mm->vm_next areas to the core file.
|
|
*/
|
|
|
|
/*
|
|
* The number of segs are recored into ELF header as 16bit value.
|
|
* Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
|
|
*/
|
|
segs = current->mm->map_count;
|
|
segs += elf_core_extra_phdrs();
|
|
|
|
gate_vma = get_gate_vma(current->mm);
|
|
if (gate_vma != NULL)
|
|
segs++;
|
|
|
|
/* for notes section */
|
|
segs++;
|
|
|
|
/* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
|
|
* this, kernel supports extended numbering. Have a look at
|
|
* include/linux/elf.h for further information. */
|
|
e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
|
|
|
|
/*
|
|
* Collect all the non-memory information about the process for the
|
|
* notes. This also sets up the file header.
|
|
*/
|
|
if (!fill_note_info(&elf, e_phnum, &info, cprm->siginfo, cprm->regs))
|
|
goto cleanup;
|
|
|
|
has_dumped = 1;
|
|
|
|
fs = get_fs();
|
|
set_fs(KERNEL_DS);
|
|
|
|
offset += sizeof(elf); /* Elf header */
|
|
offset += segs * sizeof(struct elf_phdr); /* Program headers */
|
|
|
|
/* Write notes phdr entry */
|
|
{
|
|
size_t sz = get_note_info_size(&info);
|
|
|
|
sz += elf_coredump_extra_notes_size();
|
|
|
|
phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
|
|
if (!phdr4note)
|
|
goto end_coredump;
|
|
|
|
fill_elf_note_phdr(phdr4note, sz, offset);
|
|
offset += sz;
|
|
}
|
|
|
|
dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
|
|
|
|
/*
|
|
* Zero vma process will get ZERO_SIZE_PTR here.
|
|
* Let coredump continue for register state at least.
|
|
*/
|
|
vma_filesz = kvmalloc(array_size(sizeof(*vma_filesz), (segs - 1)),
|
|
GFP_KERNEL);
|
|
if (!vma_filesz)
|
|
goto end_coredump;
|
|
|
|
for (i = 0, vma = first_vma(current, gate_vma); vma != NULL;
|
|
vma = next_vma(vma, gate_vma)) {
|
|
unsigned long dump_size;
|
|
|
|
dump_size = vma_dump_size(vma, cprm->mm_flags);
|
|
vma_filesz[i++] = dump_size;
|
|
vma_data_size += dump_size;
|
|
}
|
|
|
|
offset += vma_data_size;
|
|
offset += elf_core_extra_data_size();
|
|
e_shoff = offset;
|
|
|
|
if (e_phnum == PN_XNUM) {
|
|
shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
|
|
if (!shdr4extnum)
|
|
goto end_coredump;
|
|
fill_extnum_info(&elf, shdr4extnum, e_shoff, segs);
|
|
}
|
|
|
|
offset = dataoff;
|
|
|
|
if (!dump_emit(cprm, &elf, sizeof(elf)))
|
|
goto end_coredump;
|
|
|
|
if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
|
|
goto end_coredump;
|
|
|
|
/* Write program headers for segments dump */
|
|
for (i = 0, vma = first_vma(current, gate_vma); vma != NULL;
|
|
vma = next_vma(vma, gate_vma)) {
|
|
struct elf_phdr phdr;
|
|
|
|
phdr.p_type = PT_LOAD;
|
|
phdr.p_offset = offset;
|
|
phdr.p_vaddr = vma->vm_start;
|
|
phdr.p_paddr = 0;
|
|
phdr.p_filesz = vma_filesz[i++];
|
|
phdr.p_memsz = vma->vm_end - vma->vm_start;
|
|
offset += phdr.p_filesz;
|
|
phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
|
|
if (vma->vm_flags & VM_WRITE)
|
|
phdr.p_flags |= PF_W;
|
|
if (vma->vm_flags & VM_EXEC)
|
|
phdr.p_flags |= PF_X;
|
|
phdr.p_align = ELF_EXEC_PAGESIZE;
|
|
|
|
if (!dump_emit(cprm, &phdr, sizeof(phdr)))
|
|
goto end_coredump;
|
|
}
|
|
|
|
if (!elf_core_write_extra_phdrs(cprm, offset))
|
|
goto end_coredump;
|
|
|
|
/* write out the notes section */
|
|
if (!write_note_info(&info, cprm))
|
|
goto end_coredump;
|
|
|
|
if (elf_coredump_extra_notes_write(cprm))
|
|
goto end_coredump;
|
|
|
|
/* Align to page */
|
|
if (!dump_skip(cprm, dataoff - cprm->pos))
|
|
goto end_coredump;
|
|
|
|
for (i = 0, vma = first_vma(current, gate_vma); vma != NULL;
|
|
vma = next_vma(vma, gate_vma)) {
|
|
unsigned long addr;
|
|
unsigned long end;
|
|
|
|
end = vma->vm_start + vma_filesz[i++];
|
|
|
|
for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
|
|
struct page *page;
|
|
int stop;
|
|
|
|
page = get_dump_page(addr);
|
|
if (page) {
|
|
void *kaddr = kmap(page);
|
|
stop = !dump_emit(cprm, kaddr, PAGE_SIZE);
|
|
kunmap(page);
|
|
put_page(page);
|
|
} else
|
|
stop = !dump_skip(cprm, PAGE_SIZE);
|
|
if (stop)
|
|
goto end_coredump;
|
|
}
|
|
}
|
|
dump_truncate(cprm);
|
|
|
|
if (!elf_core_write_extra_data(cprm))
|
|
goto end_coredump;
|
|
|
|
if (e_phnum == PN_XNUM) {
|
|
if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
|
|
goto end_coredump;
|
|
}
|
|
|
|
end_coredump:
|
|
set_fs(fs);
|
|
|
|
cleanup:
|
|
free_note_info(&info);
|
|
kfree(shdr4extnum);
|
|
kvfree(vma_filesz);
|
|
kfree(phdr4note);
|
|
return has_dumped;
|
|
}
|
|
|
|
#endif /* CONFIG_ELF_CORE */
|
|
|
|
static int __init init_elf_binfmt(void)
|
|
{
|
|
register_binfmt(&elf_format);
|
|
return 0;
|
|
}
|
|
|
|
static void __exit exit_elf_binfmt(void)
|
|
{
|
|
/* Remove the COFF and ELF loaders. */
|
|
unregister_binfmt(&elf_format);
|
|
}
|
|
|
|
core_initcall(init_elf_binfmt);
|
|
module_exit(exit_elf_binfmt);
|
|
MODULE_LICENSE("GPL");
|