/* * linux/fs/binfmt_aout.c * * Copyright (C) 1991, 1992, 1996 Linus Torvalds * * Hacked a bit by DaveM to make it work with 32-bit SunOS * binaries on the sparc64 port. */ #include <linux/module.h> #include <linux/sched.h> #include <linux/kernel.h> #include <linux/mm.h> #include <linux/mman.h> #include <linux/a.out.h> #include <linux/errno.h> #include <linux/signal.h> #include <linux/string.h> #include <linux/fs.h> #include <linux/file.h> #include <linux/stat.h> #include <linux/fcntl.h> #include <linux/ptrace.h> #include <linux/user.h> #include <linux/slab.h> #include <linux/binfmts.h> #include <linux/personality.h> #include <linux/init.h> #include <asm/system.h> #include <asm/uaccess.h> #include <asm/pgalloc.h> #include <asm/mmu_context.h> static int load_aout32_binary(struct linux_binprm *, struct pt_regs * regs); static int load_aout32_library(struct file*); static int aout32_core_dump(long signr, struct pt_regs * regs, struct file *file); static struct linux_binfmt aout32_format = { NULL, THIS_MODULE, load_aout32_binary, load_aout32_library, aout32_core_dump, PAGE_SIZE }; static void set_brk(unsigned long start, unsigned long end) { start = PAGE_ALIGN(start); end = PAGE_ALIGN(end); if (end <= start) return; down_write(¤t->mm->mmap_sem); do_brk(start, end - start); up_write(¤t->mm->mmap_sem); } /* * These are the only things you should do on a core-file: use only these * macros to write out all the necessary info. */ static int dump_write(struct file *file, const void *addr, int nr) { return file->f_op->write(file, addr, nr, &file->f_pos) == nr; } #define DUMP_WRITE(addr, nr) \ if (!dump_write(file, (void *)(addr), (nr))) \ goto end_coredump; #define DUMP_SEEK(offset) \ if (file->f_op->llseek) { \ if (file->f_op->llseek(file,(offset),0) != (offset)) \ goto end_coredump; \ } else file->f_pos = (offset) /* * Routine writes a core dump image in the current directory. * Currently only a stub-function. * * Note that setuid/setgid files won't make a core-dump if the uid/gid * changed due to the set[u|g]id. It's enforced by the "current->mm->dumpable" * field, which also makes sure the core-dumps won't be recursive if the * dumping of the process results in another error.. */ static int aout32_core_dump(long signr, struct pt_regs *regs, struct file *file) { mm_segment_t fs; int has_dumped = 0; unsigned long dump_start, dump_size; struct user dump; # define START_DATA(u) (u.u_tsize) # define START_STACK(u) ((regs->u_regs[UREG_FP]) & ~(PAGE_SIZE - 1)) fs = get_fs(); set_fs(KERNEL_DS); has_dumped = 1; current->flags |= PF_DUMPCORE; strncpy(dump.u_comm, current->comm, sizeof(dump.u_comm)); dump.signal = signr; dump_thread(regs, &dump); /* If the size of the dump file exceeds the rlimit, then see what would happen if we wrote the stack, but not the data area. */ if ((dump.u_dsize+dump.u_ssize) > current->signal->rlim[RLIMIT_CORE].rlim_cur) dump.u_dsize = 0; /* Make sure we have enough room to write the stack and data areas. */ if ((dump.u_ssize) > current->signal->rlim[RLIMIT_CORE].rlim_cur) dump.u_ssize = 0; /* make sure we actually have a data and stack area to dump */ set_fs(USER_DS); if (!access_ok(VERIFY_READ, (void __user *) START_DATA(dump), dump.u_dsize)) dump.u_dsize = 0; if (!access_ok(VERIFY_READ, (void __user *) START_STACK(dump), dump.u_ssize)) dump.u_ssize = 0; set_fs(KERNEL_DS); /* struct user */ DUMP_WRITE(&dump,sizeof(dump)); /* now we start writing out the user space info */ set_fs(USER_DS); /* Dump the data area */ if (dump.u_dsize != 0) { dump_start = START_DATA(dump); dump_size = dump.u_dsize; DUMP_WRITE(dump_start,dump_size); } /* Now prepare to dump the stack area */ if (dump.u_ssize != 0) { dump_start = START_STACK(dump); dump_size = dump.u_ssize; DUMP_WRITE(dump_start,dump_size); } /* Finally dump the task struct. Not be used by gdb, but could be useful */ set_fs(KERNEL_DS); DUMP_WRITE(current,sizeof(*current)); end_coredump: set_fs(fs); return has_dumped; } /* * create_aout32_tables() parses the env- and arg-strings in new user * memory and creates the pointer tables from them, and puts their * addresses on the "stack", returning the new stack pointer value. */ static u32 __user *create_aout32_tables(char __user *p, struct linux_binprm *bprm) { u32 __user *argv; u32 __user *envp; u32 __user *sp; int argc = bprm->argc; int envc = bprm->envc; sp = (u32 __user *)((-(unsigned long)sizeof(char *))&(unsigned long)p); /* This imposes the proper stack alignment for a new process. */ sp = (u32 __user *) (((unsigned long) sp) & ~7); if ((envc+argc+3)&1) --sp; sp -= envc+1; envp = sp; sp -= argc+1; argv = sp; put_user(argc,--sp); current->mm->arg_start = (unsigned long) p; while (argc-->0) { char c; put_user(((u32)(unsigned long)(p)),argv++); do { get_user(c,p++); } while (c); } put_user(NULL,argv); current->mm->arg_end = current->mm->env_start = (unsigned long) p; while (envc-->0) { char c; put_user(((u32)(unsigned long)(p)),envp++); do { get_user(c,p++); } while (c); } put_user(NULL,envp); current->mm->env_end = (unsigned long) p; return sp; } /* * These are the functions used to load a.out style executables and shared * libraries. There is no binary dependent code anywhere else. */ static int load_aout32_binary(struct linux_binprm * bprm, struct pt_regs * regs) { struct exec ex; unsigned long error; unsigned long fd_offset; unsigned long rlim; unsigned long orig_thr_flags; int retval; ex = *((struct exec *) bprm->buf); /* exec-header */ if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC && N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) || N_TRSIZE(ex) || N_DRSIZE(ex) || bprm->file->f_path.dentry->d_inode->i_size < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) { return -ENOEXEC; } fd_offset = N_TXTOFF(ex); /* Check initial limits. This avoids letting people circumvent * size limits imposed on them by creating programs with large * arrays in the data or bss. */ rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur; if (rlim >= RLIM_INFINITY) rlim = ~0; if (ex.a_data + ex.a_bss > rlim) return -ENOMEM; /* Flush all traces of the currently running executable */ retval = flush_old_exec(bprm); if (retval) return retval; /* OK, This is the point of no return */ set_personality(PER_SUNOS); current->mm->end_code = ex.a_text + (current->mm->start_code = N_TXTADDR(ex)); current->mm->end_data = ex.a_data + (current->mm->start_data = N_DATADDR(ex)); current->mm->brk = ex.a_bss + (current->mm->start_brk = N_BSSADDR(ex)); current->mm->free_area_cache = current->mm->mmap_base; current->mm->cached_hole_size = 0; current->mm->mmap = NULL; compute_creds(bprm); current->flags &= ~PF_FORKNOEXEC; if (N_MAGIC(ex) == NMAGIC) { loff_t pos = fd_offset; /* Fuck me plenty... */ down_write(¤t->mm->mmap_sem); error = do_brk(N_TXTADDR(ex), ex.a_text); up_write(¤t->mm->mmap_sem); bprm->file->f_op->read(bprm->file, (char __user *)N_TXTADDR(ex), ex.a_text, &pos); down_write(¤t->mm->mmap_sem); error = do_brk(N_DATADDR(ex), ex.a_data); up_write(¤t->mm->mmap_sem); bprm->file->f_op->read(bprm->file, (char __user *)N_DATADDR(ex), ex.a_data, &pos); goto beyond_if; } if (N_MAGIC(ex) == OMAGIC) { loff_t pos = fd_offset; down_write(¤t->mm->mmap_sem); do_brk(N_TXTADDR(ex) & PAGE_MASK, ex.a_text+ex.a_data + PAGE_SIZE - 1); up_write(¤t->mm->mmap_sem); bprm->file->f_op->read(bprm->file, (char __user *)N_TXTADDR(ex), ex.a_text+ex.a_data, &pos); } else { static unsigned long error_time; if ((ex.a_text & 0xfff || ex.a_data & 0xfff) && (N_MAGIC(ex) != NMAGIC) && (jiffies-error_time) > 5*HZ) { printk(KERN_NOTICE "executable not page aligned\n"); error_time = jiffies; } if (!bprm->file->f_op->mmap) { loff_t pos = fd_offset; down_write(¤t->mm->mmap_sem); do_brk(0, ex.a_text+ex.a_data); up_write(¤t->mm->mmap_sem); bprm->file->f_op->read(bprm->file, (char __user *)N_TXTADDR(ex), ex.a_text+ex.a_data, &pos); goto beyond_if; } down_write(¤t->mm->mmap_sem); error = do_mmap(bprm->file, N_TXTADDR(ex), ex.a_text, PROT_READ | PROT_EXEC, MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE, fd_offset); up_write(¤t->mm->mmap_sem); if (error != N_TXTADDR(ex)) { send_sig(SIGKILL, current, 0); return error; } down_write(¤t->mm->mmap_sem); error = do_mmap(bprm->file, N_DATADDR(ex), ex.a_data, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE, fd_offset + ex.a_text); up_write(¤t->mm->mmap_sem); if (error != N_DATADDR(ex)) { send_sig(SIGKILL, current, 0); return error; } } beyond_if: set_binfmt(&aout32_format); set_brk(current->mm->start_brk, current->mm->brk); /* Make sure STACK_TOP returns the right thing. */ orig_thr_flags = current_thread_info()->flags; current_thread_info()->flags |= _TIF_32BIT; retval = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT); if (retval < 0) { current_thread_info()->flags = orig_thr_flags; /* Someone check-me: is this error path enough? */ send_sig(SIGKILL, current, 0); return retval; } current->mm->start_stack = (unsigned long) create_aout32_tables((char __user *)bprm->p, bprm); tsb_context_switch(current->mm); start_thread32(regs, ex.a_entry, current->mm->start_stack); if (current->ptrace & PT_PTRACED) send_sig(SIGTRAP, current, 0); return 0; } /* N.B. Move to .h file and use code in fs/binfmt_aout.c? */ static int load_aout32_library(struct file *file) { struct inode * inode; unsigned long bss, start_addr, len; unsigned long error; int retval; struct exec ex; inode = file->f_path.dentry->d_inode; retval = -ENOEXEC; error = kernel_read(file, 0, (char *) &ex, sizeof(ex)); if (error != sizeof(ex)) goto out; /* We come in here for the regular a.out style of shared libraries */ if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) || N_TRSIZE(ex) || N_DRSIZE(ex) || ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) || inode->i_size < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) { goto out; } if (N_MAGIC(ex) == ZMAGIC && N_TXTOFF(ex) && (N_TXTOFF(ex) < inode->i_sb->s_blocksize)) { printk("N_TXTOFF < BLOCK_SIZE. Please convert library\n"); goto out; } if (N_FLAGS(ex)) goto out; /* For QMAGIC, the starting address is 0x20 into the page. We mask this off to get the starting address for the page */ start_addr = ex.a_entry & 0xfffff000; /* Now use mmap to map the library into memory. */ down_write(¤t->mm->mmap_sem); error = do_mmap(file, start_addr, ex.a_text + ex.a_data, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE, N_TXTOFF(ex)); up_write(¤t->mm->mmap_sem); retval = error; if (error != start_addr) goto out; len = PAGE_ALIGN(ex.a_text + ex.a_data); bss = ex.a_text + ex.a_data + ex.a_bss; if (bss > len) { down_write(¤t->mm->mmap_sem); error = do_brk(start_addr + len, bss - len); up_write(¤t->mm->mmap_sem); retval = error; if (error != start_addr + len) goto out; } retval = 0; out: return retval; } static int __init init_aout32_binfmt(void) { return register_binfmt(&aout32_format); } static void __exit exit_aout32_binfmt(void) { unregister_binfmt(&aout32_format); } module_init(init_aout32_binfmt); module_exit(exit_aout32_binfmt);