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author | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
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committer | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
commit | 871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch) | |
tree | 8718f573808810c2a1e8cb8fb6ac469093ca2784 /fs/binfmt_elf.c | |
parent | 9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff) | |
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Moved, renamed, and deleted files
The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.
Diffstat (limited to 'fs/binfmt_elf.c')
-rw-r--r-- | fs/binfmt_elf.c | 2122 |
1 files changed, 2122 insertions, 0 deletions
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c new file mode 100644 index 00000000..16f73541 --- /dev/null +++ b/fs/binfmt_elf.c @@ -0,0 +1,2122 @@ +/* + * linux/fs/binfmt_elf.c + * + * These are the functions used to load ELF format executables as used + * on SVr4 machines. Information on the format may be found in the book + * "UNIX SYSTEM V RELEASE 4 Programmers Guide: Ansi C and Programming Support + * Tools". + * + * Copyright 1993, 1994: Eric Youngdale (ericy@cais.com). + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/fs.h> +#include <linux/mm.h> +#include <linux/mman.h> +#include <linux/errno.h> +#include <linux/signal.h> +#include <linux/binfmts.h> +#include <linux/string.h> +#include <linux/file.h> +#include <linux/slab.h> +#include <linux/personality.h> +#include <linux/elfcore.h> +#include <linux/init.h> +#include <linux/highuid.h> +#include <linux/compiler.h> +#include <linux/highmem.h> +#include <linux/pagemap.h> +#include <linux/security.h> +#include <linux/random.h> +#include <linux/elf.h> +#include <linux/utsname.h> +#include <linux/coredump.h> +#include <asm/uaccess.h> +#include <asm/param.h> +#include <asm/page.h> +#include <asm/exec.h> + +static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs); +static int load_elf_library(struct file *); +static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *, + int, int, unsigned long); + +/* + * If we don't support core dumping, then supply a NULL so we + * don't even try. + */ +#ifdef CONFIG_ELF_CORE +static int elf_core_dump(struct coredump_params *cprm); +#else +#define elf_core_dump NULL +#endif + +#if ELF_EXEC_PAGESIZE > PAGE_SIZE +#define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE +#else +#define ELF_MIN_ALIGN PAGE_SIZE +#endif + +#ifndef ELF_CORE_EFLAGS +#define ELF_CORE_EFLAGS 0 +#endif + +#define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1)) +#define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1)) +#define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1)) + +static struct linux_binfmt elf_format = { + .module = THIS_MODULE, + .load_binary = load_elf_binary, + .load_shlib = load_elf_library, + .core_dump = elf_core_dump, + .min_coredump = ELF_EXEC_PAGESIZE, +}; + +#define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE) + +static int set_brk(unsigned long start, unsigned long end) +{ + start = ELF_PAGEALIGN(start); + end = ELF_PAGEALIGN(end); + if (end > start) { + unsigned long addr; + addr = vm_brk(start, end - start); + if (BAD_ADDR(addr)) + return addr; + } + current->mm->start_brk = current->mm->brk = end; + return 0; +} + +/* We need to explicitly zero any fractional pages + after the data section (i.e. bss). This would + contain the junk from the file that should not + be in memory + */ +static int padzero(unsigned long elf_bss) +{ + unsigned long nbyte; + + nbyte = ELF_PAGEOFFSET(elf_bss); + if (nbyte) { + nbyte = ELF_MIN_ALIGN - nbyte; + if (clear_user((void __user *) elf_bss, nbyte)) + return -EFAULT; + } + return 0; +} + +/* Let's use some macros to make this stack manipulation a little clearer */ +#ifdef CONFIG_STACK_GROWSUP +#define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items)) +#define STACK_ROUND(sp, items) \ + ((15 + (unsigned long) ((sp) + (items))) &~ 15UL) +#define STACK_ALLOC(sp, len) ({ \ + elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \ + old_sp; }) +#else +#define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items)) +#define STACK_ROUND(sp, items) \ + (((unsigned long) (sp - items)) &~ 15UL) +#define STACK_ALLOC(sp, len) ({ sp -= len ; sp; }) +#endif + +#ifndef ELF_BASE_PLATFORM +/* + * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture. + * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value + * will be copied to the user stack in the same manner as AT_PLATFORM. + */ +#define ELF_BASE_PLATFORM NULL +#endif + +static int +create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec, + unsigned long load_addr, unsigned long interp_load_addr) +{ + unsigned long p = bprm->p; + int argc = bprm->argc; + int envc = bprm->envc; + elf_addr_t __user *argv; + elf_addr_t __user *envp; + elf_addr_t __user *sp; + elf_addr_t __user *u_platform; + elf_addr_t __user *u_base_platform; + elf_addr_t __user *u_rand_bytes; + const char *k_platform = ELF_PLATFORM; + const char *k_base_platform = ELF_BASE_PLATFORM; + unsigned char k_rand_bytes[16]; + int items; + elf_addr_t *elf_info; + int ei_index = 0; + const struct cred *cred = current_cred(); + struct vm_area_struct *vma; + + /* + * In some cases (e.g. Hyper-Threading), we want to avoid L1 + * evictions by the processes running on the same package. One + * thing we can do is to shuffle the initial stack for them. + */ + + p = arch_align_stack(p); + + /* + * If this architecture has a platform capability string, copy it + * to userspace. In some cases (Sparc), this info is impossible + * for userspace to get any other way, in others (i386) it is + * merely difficult. + */ + u_platform = NULL; + if (k_platform) { + size_t len = strlen(k_platform) + 1; + + u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len); + if (__copy_to_user(u_platform, k_platform, len)) + return -EFAULT; + } + + /* + * If this architecture has a "base" platform capability + * string, copy it to userspace. + */ + u_base_platform = NULL; + if (k_base_platform) { + size_t len = strlen(k_base_platform) + 1; + + u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len); + if (__copy_to_user(u_base_platform, k_base_platform, len)) + return -EFAULT; + } + + /* + * Generate 16 random bytes for userspace PRNG seeding. + */ + get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes)); + u_rand_bytes = (elf_addr_t __user *) + STACK_ALLOC(p, sizeof(k_rand_bytes)); + if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes))) + return -EFAULT; + + /* Create the ELF interpreter info */ + elf_info = (elf_addr_t *)current->mm->saved_auxv; + /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */ +#define NEW_AUX_ENT(id, val) \ + do { \ + elf_info[ei_index++] = id; \ + elf_info[ei_index++] = val; \ + } while (0) + +#ifdef ARCH_DLINFO + /* + * ARCH_DLINFO must come first so PPC can do its special alignment of + * AUXV. + * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in + * ARCH_DLINFO changes + */ + ARCH_DLINFO; +#endif + NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP); + NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE); + NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); + NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff); + NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); + NEW_AUX_ENT(AT_PHNUM, exec->e_phnum); + NEW_AUX_ENT(AT_BASE, interp_load_addr); + NEW_AUX_ENT(AT_FLAGS, 0); + NEW_AUX_ENT(AT_ENTRY, exec->e_entry); + NEW_AUX_ENT(AT_UID, cred->uid); + NEW_AUX_ENT(AT_EUID, cred->euid); + NEW_AUX_ENT(AT_GID, cred->gid); + NEW_AUX_ENT(AT_EGID, cred->egid); + NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm)); + NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes); + NEW_AUX_ENT(AT_EXECFN, bprm->exec); + if (k_platform) { + NEW_AUX_ENT(AT_PLATFORM, + (elf_addr_t)(unsigned long)u_platform); + } + if (k_base_platform) { + NEW_AUX_ENT(AT_BASE_PLATFORM, + (elf_addr_t)(unsigned long)u_base_platform); + } + if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) { + NEW_AUX_ENT(AT_EXECFD, bprm->interp_data); + } +#undef NEW_AUX_ENT + /* AT_NULL is zero; clear the rest too */ + memset(&elf_info[ei_index], 0, + sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]); + + /* And advance past the AT_NULL entry. */ + ei_index += 2; + + sp = STACK_ADD(p, ei_index); + + items = (argc + 1) + (envc + 1) + 1; + bprm->p = STACK_ROUND(sp, items); + + /* Point sp at the lowest address on the stack */ +#ifdef CONFIG_STACK_GROWSUP + sp = (elf_addr_t __user *)bprm->p - items - ei_index; + bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */ +#else + sp = (elf_addr_t __user *)bprm->p; +#endif + + + /* + * Grow the stack manually; some architectures have a limit on how + * far ahead a user-space access may be in order to grow the stack. + */ + vma = find_extend_vma(current->mm, bprm->p); + if (!vma) + return -EFAULT; + + /* Now, let's put argc (and argv, envp if appropriate) on the stack */ + if (__put_user(argc, sp++)) + return -EFAULT; + argv = sp; + envp = argv + argc + 1; + + /* Populate argv and envp */ + p = current->mm->arg_end = current->mm->arg_start; + while (argc-- > 0) { + size_t len; + if (__put_user((elf_addr_t)p, argv++)) + return -EFAULT; + len = strnlen_user((void __user *)p, MAX_ARG_STRLEN); + if (!len || len > MAX_ARG_STRLEN) + return -EINVAL; + p += len; + } + if (__put_user(0, argv)) + return -EFAULT; + current->mm->arg_end = current->mm->env_start = p; + while (envc-- > 0) { + size_t len; + if (__put_user((elf_addr_t)p, envp++)) + return -EFAULT; + len = strnlen_user((void __user *)p, MAX_ARG_STRLEN); + if (!len || len > MAX_ARG_STRLEN) + return -EINVAL; + p += len; + } + if (__put_user(0, envp)) + return -EFAULT; + current->mm->env_end = p; + + /* Put the elf_info on the stack in the right place. */ + sp = (elf_addr_t __user *)envp + 1; + if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t))) + return -EFAULT; + return 0; +} + +static unsigned long elf_map(struct file *filep, unsigned long addr, + struct elf_phdr *eppnt, int prot, int type, + unsigned long total_size) +{ + unsigned long map_addr; + unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr); + unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr); + addr = ELF_PAGESTART(addr); + size = ELF_PAGEALIGN(size); + + /* mmap() will return -EINVAL if given a zero size, but a + * segment with zero filesize is perfectly valid */ + if (!size) + return addr; + + down_write(¤t->mm->mmap_sem); + /* + * total_size is the size of the ELF (interpreter) image. + * The _first_ mmap needs to know the full size, otherwise + * randomization might put this image into an overlapping + * position with the ELF binary image. (since size < total_size) + * So we first map the 'big' image - and unmap the remainder at + * the end. (which unmap is needed for ELF images with holes.) + */ + if (total_size) { + total_size = ELF_PAGEALIGN(total_size); + map_addr = do_mmap(filep, addr, total_size, prot, type, off); + if (!BAD_ADDR(map_addr)) + do_munmap(current->mm, map_addr+size, total_size-size); + } else + map_addr = do_mmap(filep, addr, size, prot, type, off); + + up_write(¤t->mm->mmap_sem); + return(map_addr); +} + +static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr) +{ + int i, first_idx = -1, last_idx = -1; + + for (i = 0; i < nr; i++) { + if (cmds[i].p_type == PT_LOAD) { + last_idx = i; + if (first_idx == -1) + first_idx = i; + } + } + if (first_idx == -1) + return 0; + + return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz - + ELF_PAGESTART(cmds[first_idx].p_vaddr); +} + + +/* 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 *interp_map_addr, + unsigned long no_base) +{ + struct elf_phdr *elf_phdata; + struct elf_phdr *eppnt; + unsigned long load_addr = 0; + int load_addr_set = 0; + unsigned long last_bss = 0, elf_bss = 0; + unsigned long error = ~0UL; + unsigned long total_size; + int retval, i, size; + + /* 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)) + goto out; + if (!interpreter->f_op || !interpreter->f_op->mmap) + goto out; + + /* + * If the size of this structure has changed, then punt, since + * we will be doing the wrong thing. + */ + if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr)) + goto out; + if (interp_elf_ex->e_phnum < 1 || + interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr)) + goto out; + + /* Now read in all of the header information */ + size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum; + if (size > ELF_MIN_ALIGN) + goto out; + elf_phdata = kmalloc(size, GFP_KERNEL); + if (!elf_phdata) + goto out; + + retval = kernel_read(interpreter, interp_elf_ex->e_phoff, + (char *)elf_phdata, size); + error = -EIO; + if (retval != size) { + if (retval < 0) + error = retval; + goto out_close; + } + + total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum); + if (!total_size) { + error = -EINVAL; + goto out_close; + } + + eppnt = 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 = 0; + unsigned long vaddr = 0; + unsigned long k, map_addr; + + if (eppnt->p_flags & PF_R) + elf_prot = PROT_READ; + if (eppnt->p_flags & PF_W) + elf_prot |= PROT_WRITE; + if (eppnt->p_flags & PF_X) + elf_prot |= PROT_EXEC; + vaddr = eppnt->p_vaddr; + if (interp_elf_ex->e_type == ET_EXEC || load_addr_set) + elf_type |= MAP_FIXED; + 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; + if (!*interp_map_addr) + *interp_map_addr = map_addr; + error = map_addr; + if (BAD_ADDR(map_addr)) + goto out_close; + + 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_close; + } + + /* + * 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_memsz + eppnt->p_vaddr; + if (k > last_bss) + last_bss = k; + } + } + + if (last_bss > elf_bss) { + /* + * Now fill out the bss section. First pad the last page up + * to the page boundary, and then perform a mmap to make sure + * that there are zero-mapped pages up to and including the + * last bss page. + */ + if (padzero(elf_bss)) { + error = -EFAULT; + goto out_close; + } + + /* What we have mapped so far */ + elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1); + + /* Map the last of the bss segment */ + error = vm_brk(elf_bss, last_bss - elf_bss); + if (BAD_ADDR(error)) + goto out_close; + } + + error = load_addr; + +out_close: + kfree(elf_phdata); +out: + return error; +} + +/* + * These are the functions used to load ELF style executables and shared + * libraries. There is no binary dependent code anywhere else. + */ + +#define INTERPRETER_NONE 0 +#define INTERPRETER_ELF 2 + +#ifndef STACK_RND_MASK +#define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */ +#endif + +static unsigned long randomize_stack_top(unsigned long stack_top) +{ + unsigned int random_variable = 0; + + if ((current->flags & PF_RANDOMIZE) && + !(current->personality & ADDR_NO_RANDOMIZE)) { + random_variable = get_random_int() & STACK_RND_MASK; + random_variable <<= PAGE_SHIFT; + } +#ifdef CONFIG_STACK_GROWSUP + return PAGE_ALIGN(stack_top) + random_variable; +#else + return PAGE_ALIGN(stack_top) - random_variable; +#endif +} + +static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs) +{ + struct file *interpreter = NULL; /* to shut gcc up */ + unsigned long load_addr = 0, load_bias = 0; + int load_addr_set = 0; + char * elf_interpreter = NULL; + unsigned long error; + struct elf_phdr *elf_ppnt, *elf_phdata; + unsigned long elf_bss, elf_brk; + int retval, i; + unsigned int size; + unsigned long elf_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; + unsigned long def_flags = 0; + struct { + struct elfhdr elf_ex; + struct elfhdr interp_elf_ex; + } *loc; + + loc = kmalloc(sizeof(*loc), GFP_KERNEL); + if (!loc) { + retval = -ENOMEM; + goto out_ret; + } + + /* Get the exec-header */ + loc->elf_ex = *((struct elfhdr *)bprm->buf); + + retval = -ENOEXEC; + /* First of all, some simple consistency checks */ + if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0) + goto out; + + if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN) + goto out; + if (!elf_check_arch(&loc->elf_ex)) + goto out; + if (!bprm->file->f_op || !bprm->file->f_op->mmap) + goto out; + + /* Now read in all of the header information */ + if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr)) + goto out; + if (loc->elf_ex.e_phnum < 1 || + loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr)) + goto out; + size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr); + retval = -ENOMEM; + elf_phdata = kmalloc(size, GFP_KERNEL); + if (!elf_phdata) + goto out; + + retval = kernel_read(bprm->file, loc->elf_ex.e_phoff, + (char *)elf_phdata, size); + if (retval != size) { + if (retval >= 0) + retval = -EIO; + goto out_free_ph; + } + + elf_ppnt = elf_phdata; + elf_bss = 0; + elf_brk = 0; + + start_code = ~0UL; + end_code = 0; + start_data = 0; + end_data = 0; + + for (i = 0; i < loc->elf_ex.e_phnum; i++) { + if (elf_ppnt->p_type == PT_INTERP) { + /* 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 = kernel_read(bprm->file, elf_ppnt->p_offset, + elf_interpreter, + elf_ppnt->p_filesz); + if (retval != elf_ppnt->p_filesz) { + if (retval >= 0) + retval = -EIO; + 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); + retval = PTR_ERR(interpreter); + if (IS_ERR(interpreter)) + goto out_free_interp; + + /* + * If the binary is not readable then enforce + * mm->dumpable = 0 regardless of the interpreter's + * permissions. + */ + would_dump(bprm, interpreter); + + retval = kernel_read(interpreter, 0, bprm->buf, + BINPRM_BUF_SIZE); + if (retval != BINPRM_BUF_SIZE) { + if (retval >= 0) + retval = -EIO; + goto out_free_dentry; + } + + /* Get the exec headers */ + loc->interp_elf_ex = *((struct elfhdr *)bprm->buf); + break; + } + elf_ppnt++; + } + + elf_ppnt = elf_phdata; + for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++) + if (elf_ppnt->p_type == PT_GNU_STACK) { + if (elf_ppnt->p_flags & PF_X) + executable_stack = EXSTACK_ENABLE_X; + else + executable_stack = EXSTACK_DISABLE_X; + break; + } + + /* Some simple consistency checks for the interpreter */ + if (elf_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)) + goto out_free_dentry; + } + + /* Flush all traces of the currently running executable */ + retval = flush_old_exec(bprm); + if (retval) + goto out_free_dentry; + + /* OK, This is the point of no return */ + current->mm->def_flags = def_flags; + + /* Do this immediately, since STACK_TOP as used in setup_arg_pages + may depend on the personality. */ + SET_PERSONALITY(loc->elf_ex); + if (elf_read_implies_exec(loc->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); + + /* Do this so that we can load the interpreter, if need be. We will + change some of these later */ + current->mm->free_area_cache = current->mm->mmap_base; + current->mm->cached_hole_size = 0; + retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP), + executable_stack); + if (retval < 0) { + send_sig(SIGKILL, current, 0); + goto out_free_dentry; + } + + current->mm->start_stack = bprm->p; + + /* 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 < loc->elf_ex.e_phnum; i++, elf_ppnt++) { + int elf_prot = 0, elf_flags; + unsigned long k, vaddr; + + 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); + if (retval) { + send_sig(SIGKILL, current, 0); + 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 + */ + } + } + } + + if (elf_ppnt->p_flags & PF_R) + elf_prot |= PROT_READ; + if (elf_ppnt->p_flags & PF_W) + elf_prot |= PROT_WRITE; + if (elf_ppnt->p_flags & PF_X) + elf_prot |= PROT_EXEC; + + elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE; + + vaddr = elf_ppnt->p_vaddr; + if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) { + elf_flags |= MAP_FIXED; + } else if (loc->elf_ex.e_type == ET_DYN) { + /* Try and get dynamic programs out of the way of the + * default mmap base, as well as whatever program they + * might try to exec. This is because the brk will + * follow the loader, and is not movable. */ +#ifdef CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE + /* Memory randomization might have been switched off + * in runtime via sysctl. + * If that is the case, retain the original non-zero + * load_bias value in order to establish proper + * non-randomized mappings. + */ + if (current->flags & PF_RANDOMIZE) + load_bias = 0; + else + load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr); +#else + load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr); +#endif + } + + error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt, + elf_prot, elf_flags, 0); + if (BAD_ADDR(error)) { + send_sig(SIGKILL, current, 0); + 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 (loc->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 (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. */ + send_sig(SIGKILL, current, 0); + 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) + elf_brk = k; + } + + loc->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); + if (retval) { + send_sig(SIGKILL, current, 0); + goto out_free_dentry; + } + if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) { + send_sig(SIGSEGV, current, 0); + retval = -EFAULT; /* Nobody gets to see this, but.. */ + goto out_free_dentry; + } + + if (elf_interpreter) { + unsigned long uninitialized_var(interp_map_addr); + + elf_entry = load_elf_interp(&loc->interp_elf_ex, + interpreter, + &interp_map_addr, + load_bias); + 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)) { + force_sig(SIGSEGV, current); + 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); + kfree(elf_interpreter); + } else { + elf_entry = loc->elf_ex.e_entry; + if (BAD_ADDR(elf_entry)) { + force_sig(SIGSEGV, current); + retval = -EINVAL; + goto out_free_dentry; + } + } + + kfree(elf_phdata); + + set_binfmt(&elf_format); + +#ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES + retval = arch_setup_additional_pages(bprm, !!elf_interpreter); + if (retval < 0) { + send_sig(SIGKILL, current, 0); + goto out; + } +#endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */ + + install_exec_creds(bprm); + retval = create_elf_tables(bprm, &loc->elf_ex, + load_addr, interp_load_addr); + if (retval < 0) { + send_sig(SIGKILL, current, 0); + goto out; + } + /* N.B. passed_fileno might not be initialized? */ + current->mm->end_code = end_code; + current->mm->start_code = start_code; + current->mm->start_data = start_data; + current->mm->end_data = end_data; + current->mm->start_stack = bprm->p; + +#ifdef arch_randomize_brk + if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) { + current->mm->brk = current->mm->start_brk = + arch_randomize_brk(current->mm); +#ifdef CONFIG_COMPAT_BRK + current->brk_randomized = 1; +#endif + } +#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); + } + +#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 + + start_thread(regs, elf_entry, bprm->p); + retval = 0; +out: + kfree(loc); +out_ret: + return retval; + + /* error cleanup */ +out_free_dentry: + allow_write_access(interpreter); + if (interpreter) + fput(interpreter); +out_free_interp: + kfree(elf_interpreter); +out_free_ph: + kfree(elf_phdata); + goto out; +} + +/* 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 = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex)); + if (retval != sizeof(elf_ex)) + 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 || !file->f_op->mmap) + 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 = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j); + if (retval != j) + 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 | 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_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr + + ELF_MIN_ALIGN - 1); + bss = eppnt->p_memsz + eppnt->p_vaddr; + if (bss > len) + vm_brk(len, bss - len); + error = 0; + +out_free_ph: + kfree(elf_phdata); +out: + return error; +} + +#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; + /* + * 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_NODUMP) + 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; + } + + /* Do not dump I/O mapped devices or special mappings */ + if (vma->vm_flags & (VM_IO | VM_RESERVED)) + return 0; + + /* By default, dump shared memory if mapped from an anonymous file. */ + if (vma->vm_flags & VM_SHARED) { + if (vma->vm_file->f_path.dentry->d_inode->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; +} + +#define DUMP_WRITE(addr, nr, foffset) \ + do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0) + +static int alignfile(struct file *file, loff_t *foffset) +{ + static const char buf[4] = { 0, }; + DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset); + return 1; +} + +static int writenote(struct memelfnote *men, struct file *file, + loff_t *foffset) +{ + struct elf_note en; + en.n_namesz = strlen(men->name) + 1; + en.n_descsz = men->datasz; + en.n_type = men->type; + + DUMP_WRITE(&en, sizeof(en), foffset); + DUMP_WRITE(men->name, en.n_namesz, foffset); + if (!alignfile(file, foffset)) + return 0; + DUMP_WRITE(men->data, men->datasz, foffset); + if (!alignfile(file, foffset)) + return 0; + + return 1; +} +#undef DUMP_WRITE + +static void fill_elf_header(struct elfhdr *elf, int segs, + u16 machine, u32 flags, u8 osabi) +{ + 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; + + return; +} + +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; + return; +} + +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; + return; +} + +/* + * 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); + cputime_to_timeval(cputime.utime, &prstatus->pr_utime); + cputime_to_timeval(cputime.stime, &prstatus->pr_stime); + } else { + cputime_to_timeval(p->utime, &prstatus->pr_utime); + cputime_to_timeval(p->stime, &prstatus->pr_stime); + } + cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime); + cputime_to_timeval(p->signal->cstime, &prstatus->pr_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, cred->uid); + SET_GID(psinfo->pr_gid, 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); +} + +#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 auxv; + 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 PR_REG_SIZE +#define PR_REG_SIZE(S) sizeof(S) +#endif + +#ifndef PRSTATUS_SIZE +#define PRSTATUS_SIZE(S) sizeof(S) +#endif + +#ifndef PR_REG_PTR +#define PR_REG_PTR(S) (&((S)->pr_reg)) +#endif + +#ifndef SET_PR_FPVALID +#define SET_PR_FPVALID(S, V) ((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; + + /* + * 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, PR_REG_SIZE(t->prstatus.pr_reg), + PR_REG_PTR(&t->prstatus), NULL); + + fill_note(&t->notes[0], "CORE", NT_PRSTATUS, + PRSTATUS_SIZE(t->prstatus), &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))) { + int ret; + size_t size = regset->n * regset->size; + 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); + 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, + long signr, 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) + 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, view->ei_osabi); + + /* + * 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, signr, &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_auxv_note(&info->auxv, current->mm); + info->size += notesize(&info->auxv); + + 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 file *file, loff_t *foffset) +{ + bool first = 1; + struct elf_thread_core_info *t = info->thread; + + do { + int i; + + if (!writenote(&t->notes[0], file, foffset)) + return 0; + + if (first && !writenote(&info->psinfo, file, foffset)) + return 0; + if (first && !writenote(&info->auxv, file, foffset)) + return 0; + + for (i = 1; i < info->thread_notes; ++i) + if (t->notes[i].data && + !writenote(&t->notes[i], file, foffset)) + return 0; + + first = 0; + 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); +} + +#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 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 + 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 six ELF notes */ + info->notes = kmalloc(6 * sizeof(struct memelfnote), GFP_KERNEL); + if (!info->notes) + return 0; + info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL); + if (!info->psinfo) + goto notes_free; + info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL); + if (!info->prstatus) + goto psinfo_free; + info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL); + if (!info->fpu) + goto prstatus_free; +#ifdef ELF_CORE_COPY_XFPREGS + info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL); + if (!info->xfpu) + goto fpu_free; +#endif + return 1; +#ifdef ELF_CORE_COPY_XFPREGS + fpu_free: + kfree(info->fpu); +#endif + prstatus_free: + kfree(info->prstatus); + psinfo_free: + kfree(info->psinfo); + notes_free: + kfree(info->notes); + return 0; +} + +static int fill_note_info(struct elfhdr *elf, int phdrs, + struct elf_note_info *info, + long signr, struct pt_regs *regs) +{ + struct list_head *t; + + if (!elf_note_info_init(info)) + return 0; + + if (signr) { + struct core_thread *ct; + struct elf_thread_status *ets; + + 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(t, &info->thread_list) { + int sz; + + ets = list_entry(t, struct elf_thread_status, list); + sz = elf_dump_thread_status(signr, 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, signr); + elf_core_copy_regs(&info->prstatus->pr_reg, regs); + + /* Set up header */ + fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS, ELF_OSABI); + + /* + * 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); + + info->numnote = 2; + + fill_auxv_note(&info->notes[info->numnote++], current->mm); + + /* 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 file *file, loff_t *foffset) +{ + int i; + struct list_head *t; + + for (i = 0; i < info->numnote; i++) + if (!writenote(info->notes + i, file, foffset)) + return 0; + + /* write out the thread status notes section */ + list_for_each(t, &info->thread_list) { + struct elf_thread_status *tmp = + list_entry(t, struct elf_thread_status, list); + + for (i = 0; i < tmp->num_notes; i++) + if (!writenote(&tmp->notes[i], file, foffset)) + 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)); + } + + 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; +} + +static size_t elf_core_vma_data_size(struct vm_area_struct *gate_vma, + unsigned long mm_flags) +{ + struct vm_area_struct *vma; + size_t size = 0; + + for (vma = first_vma(current, gate_vma); vma != NULL; + vma = next_vma(vma, gate_vma)) + size += vma_dump_size(vma, mm_flags); + return size; +} + +/* + * 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; + size_t size = 0; + struct vm_area_struct *vma, *gate_vma; + struct elfhdr *elf = NULL; + loff_t offset = 0, dataoff, foffset; + struct elf_note_info info; + struct elf_phdr *phdr4note = NULL; + struct elf_shdr *shdr4extnum = NULL; + Elf_Half e_phnum; + elf_addr_t e_shoff; + + /* + * 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. + */ + + /* alloc memory for large data structures: too large to be on stack */ + elf = kmalloc(sizeof(*elf), GFP_KERNEL); + if (!elf) + goto out; + /* + * 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->signr, cprm->regs)) + goto cleanup; + + has_dumped = 1; + current->flags |= PF_DUMPCORE; + + fs = get_fs(); + set_fs(KERNEL_DS); + + offset += sizeof(*elf); /* Elf header */ + offset += segs * sizeof(struct elf_phdr); /* Program headers */ + foffset = offset; + + /* 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); + + offset += elf_core_vma_data_size(gate_vma, cprm->mm_flags); + 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; + + size += sizeof(*elf); + if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf))) + goto end_coredump; + + size += sizeof(*phdr4note); + if (size > cprm->limit + || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note))) + goto end_coredump; + + /* Write program headers for segments dump */ + for (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_dump_size(vma, cprm->mm_flags); + 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; + + size += sizeof(phdr); + if (size > cprm->limit + || !dump_write(cprm->file, &phdr, sizeof(phdr))) + goto end_coredump; + } + + if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit)) + goto end_coredump; + + /* write out the notes section */ + if (!write_note_info(&info, cprm->file, &foffset)) + goto end_coredump; + + if (elf_coredump_extra_notes_write(cprm->file, &foffset)) + goto end_coredump; + + /* Align to page */ + if (!dump_seek(cprm->file, dataoff - foffset)) + goto end_coredump; + + for (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_dump_size(vma, cprm->mm_flags); + + 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 = ((size += PAGE_SIZE) > cprm->limit) || + !dump_write(cprm->file, kaddr, + PAGE_SIZE); + kunmap(page); + page_cache_release(page); + } else + stop = !dump_seek(cprm->file, PAGE_SIZE); + if (stop) + goto end_coredump; + } + } + + if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit)) + goto end_coredump; + + if (e_phnum == PN_XNUM) { + size += sizeof(*shdr4extnum); + if (size > cprm->limit + || !dump_write(cprm->file, shdr4extnum, + sizeof(*shdr4extnum))) + goto end_coredump; + } + +end_coredump: + set_fs(fs); + +cleanup: + free_note_info(&info); + kfree(shdr4extnum); + kfree(phdr4note); + kfree(elf); +out: + 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"); |