patch-1.3.61 linux/fs/binfmt_aout.c

• Lines: 451
• Date: Thu Feb 8 06:22:11 1996
• Orig file: v1.3.60/linux/fs/binfmt_aout.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v1.3.60/linux/fs/binfmt_aout.c linux/fs/binfmt_aout.c
@@ -0,0 +1,450 @@
+/*
+ *  linux/fs/binfmt_aout.c
+ *
+ *  Copyright (C) 1991, 1992, 1996  Linus Torvalds
+ */
+
+#include <linux/module.h>
+
+#include <linux/fs.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/stat.h>
+#include <linux/fcntl.h>
+#include <linux/ptrace.h>
+#include <linux/user.h>
+#include <linux/malloc.h>
+#include <linux/binfmts.h>
+#include <linux/personality.h>
+
+#include <asm/system.h>
+#include <asm/segment.h>
+#include <asm/pgtable.h>
+
+static int load_aout_binary(struct linux_binprm *, struct pt_regs * regs);
+static int load_aout_library(int fd);
+static int aout_core_dump(long signr, struct pt_regs * regs);
+
+extern void dump_thread(struct pt_regs *, struct user *);
+
+static struct linux_binfmt aout_format = {
+#ifndef MODULE
+	NULL, NULL, load_aout_binary, load_aout_library, aout_core_dump
+#else
+	NULL, &mod_use_count_, load_aout_binary, load_aout_library, aout_core_dump
+#endif
+};
+
+static void set_brk(unsigned long start, unsigned long end)
+{
+	start = PAGE_ALIGN(start);
+	end = PAGE_ALIGN(end);
+	if (end <= start)
+		return;
+	do_mmap(NULL, start, end - start,
+		PROT_READ | PROT_WRITE | PROT_EXEC,
+		MAP_FIXED | MAP_PRIVATE, 0);
+}
+
+/*
+ * These are the only things you should do on a core-file: use only these
+ * macros to write out all the necessary info.
+ */
+#define DUMP_WRITE(addr,nr) \
+while (file.f_op->write(inode,&file,(char *)(addr),(nr)) != (nr)) goto close_coredump
+
+#define DUMP_SEEK(offset) \
+if (file.f_op->lseek) { \
+	if (file.f_op->lseek(inode,&file,(offset),0) != (offset)) \
+ 		goto close_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->dumpable"
+ * field, which also makes sure the core-dumps won't be recursive if the
+ * dumping of the process results in another error..
+ */
+
+static inline int
+do_aout_core_dump(long signr, struct pt_regs * regs)
+{
+	struct inode * inode = NULL;
+	struct file file;
+	unsigned short fs;
+	int has_dumped = 0;
+	char corefile[6+sizeof(current->comm)];
+	unsigned long dump_start, dump_size;
+	struct user dump;
+#ifdef __alpha__
+#       define START_DATA(u)	(u.start_data)
+#else
+#       define START_DATA(u)	(u.u_tsize << PAGE_SHIFT)
+#endif
+
+	if (!current->dumpable)
+		return 0;
+	current->dumpable = 0;
+
+/* See if we have enough room to write the upage.  */
+	if (current->rlim[RLIMIT_CORE].rlim_cur < PAGE_SIZE)
+		return 0;
+	fs = get_fs();
+	set_fs(KERNEL_DS);
+	memcpy(corefile,"core.",5);
+#if 0
+	memcpy(corefile+5,current->comm,sizeof(current->comm));
+#else
+	corefile[4] = '\0';
+#endif
+	if (open_namei(corefile,O_CREAT | 2 | O_TRUNC,0600,&inode,NULL)) {
+		inode = NULL;
+		goto end_coredump;
+	}
+	if (!S_ISREG(inode->i_mode))
+		goto end_coredump;
+	if (!inode->i_op || !inode->i_op->default_file_ops)
+		goto end_coredump;
+	if (get_write_access(inode))
+		goto end_coredump;
+	file.f_mode = 3;
+	file.f_flags = 0;
+	file.f_count = 1;
+	file.f_inode = inode;
+	file.f_pos = 0;
+	file.f_reada = 0;
+	file.f_op = inode->i_op->default_file_ops;
+	if (file.f_op->open)
+		if (file.f_op->open(inode,&file))
+			goto done_coredump;
+	if (!file.f_op->write)
+		goto close_coredump;
+	has_dumped = 1;
+       	strncpy(dump.u_comm, current->comm, sizeof(current->comm));
+	dump.u_ar0 = (void *)(((unsigned long)(&dump.regs)) - ((unsigned long)(&dump)));
+	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+1) * PAGE_SIZE >
+	    current->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+1) * PAGE_SIZE >
+	    current->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 (verify_area(VERIFY_READ, (void *) START_DATA(dump), dump.u_dsize << PAGE_SHIFT))
+		dump.u_dsize = 0;
+	if (verify_area(VERIFY_READ, (void *) dump.start_stack, dump.u_ssize << PAGE_SHIFT))
+		dump.u_ssize = 0;
+
+	set_fs(KERNEL_DS);
+/* struct user */
+	DUMP_WRITE(&dump,sizeof(dump));
+/* Now dump all of the user data.  Include malloced stuff as well */
+	DUMP_SEEK(PAGE_SIZE);
+/* 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 << PAGE_SHIFT;
+		DUMP_WRITE(dump_start,dump_size);
+	}
+/* Now prepare to dump the stack area */
+	if (dump.u_ssize != 0) {
+		dump_start = dump.start_stack;
+		dump_size = dump.u_ssize << PAGE_SHIFT;
+		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));
+close_coredump:
+	if (file.f_op->release)
+		file.f_op->release(inode,&file);
+done_coredump:
+	put_write_access(inode);
+end_coredump:
+	set_fs(fs);
+	iput(inode);
+	return has_dumped;
+}
+
+static int
+aout_core_dump(long signr, struct pt_regs * regs)
+{
+	int retval;
+
+	MOD_INC_USE_COUNT;
+	retval = do_aout_core_dump(signr, regs);
+	MOD_DEC_USE_COUNT;
+	return retval;
+}
+
+/*
+ * These are the functions used to load a.out style executables and shared
+ * libraries.  There is no binary dependent code anywhere else.
+ */
+
+static inline int
+do_load_aout_binary(struct linux_binprm * bprm, struct pt_regs * regs)
+{
+	struct exec ex;
+	struct file * file;
+	int fd;
+	unsigned long error;
+	unsigned long p = bprm->p;
+	unsigned long fd_offset;
+	unsigned long rlim;
+
+	ex = *((struct exec *) bprm->buf);		/* exec-header */
+	if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC && 
+	     N_MAGIC(ex) != QMAGIC) ||
+	    N_TRSIZE(ex) || N_DRSIZE(ex) ||
+	    bprm->inode->i_size < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
+		return -ENOEXEC;
+	}
+
+	current->personality = PER_LINUX;
+	fd_offset = N_TXTOFF(ex);
+
+#ifdef __i386__
+	if (N_MAGIC(ex) == ZMAGIC && fd_offset != BLOCK_SIZE) {
+		printk(KERN_NOTICE "N_TXTOFF != BLOCK_SIZE. See a.out.h.\n");
+		return -ENOEXEC;
+	}
+
+	if (N_MAGIC(ex) == ZMAGIC && ex.a_text &&
+	    (fd_offset < bprm->inode->i_sb->s_blocksize)) {
+		printk(KERN_NOTICE "N_TXTOFF < BLOCK_SIZE. Please convert binary.\n");
+		return -ENOEXEC;
+	}
+#endif
+
+	/* 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->rlim[RLIMIT_DATA].rlim_cur;
+	if (rlim >= RLIM_INFINITY)
+		rlim = ~0;
+	if (ex.a_data + ex.a_bss > rlim)
+		return -ENOMEM;
+
+	/* OK, This is the point of no return */
+	flush_old_exec(bprm);
+
+	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->rss = 0;
+	current->mm->mmap = NULL;
+	current->suid = current->euid = current->fsuid = bprm->e_uid;
+	current->sgid = current->egid = current->fsgid = bprm->e_gid;
+	if (N_MAGIC(ex) == OMAGIC) {
+#ifdef __alpha__
+		do_mmap(NULL, N_TXTADDR(ex) & PAGE_MASK,
+			ex.a_text+ex.a_data + PAGE_SIZE - 1,
+			PROT_READ|PROT_WRITE|PROT_EXEC,
+			MAP_FIXED|MAP_PRIVATE, 0);
+		read_exec(bprm->inode, fd_offset, (char *) N_TXTADDR(ex),
+			  ex.a_text+ex.a_data, 0);
+#else
+		do_mmap(NULL, 0, ex.a_text+ex.a_data,
+			PROT_READ|PROT_WRITE|PROT_EXEC,
+			MAP_FIXED|MAP_PRIVATE, 0);
+		read_exec(bprm->inode, 32, (char *) 0, ex.a_text+ex.a_data, 0);
+#endif
+	} else {
+		if (ex.a_text & 0xfff || ex.a_data & 0xfff)
+			printk(KERN_NOTICE "executable not page aligned\n");
+		
+		fd = open_inode(bprm->inode, O_RDONLY);
+		
+		if (fd < 0)
+			return fd;
+		file = current->files->fd[fd];
+		if (!file->f_op || !file->f_op->mmap) {
+			sys_close(fd);
+			do_mmap(NULL, 0, ex.a_text+ex.a_data,
+				PROT_READ|PROT_WRITE|PROT_EXEC,
+				MAP_FIXED|MAP_PRIVATE, 0);
+			read_exec(bprm->inode, fd_offset,
+				  (char *) N_TXTADDR(ex), ex.a_text+ex.a_data, 0);
+			goto beyond_if;
+		}
+
+		error = do_mmap(file, N_TXTADDR(ex), ex.a_text,
+			PROT_READ | PROT_EXEC,
+			MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
+			fd_offset);
+
+		if (error != N_TXTADDR(ex)) {
+			sys_close(fd);
+			send_sig(SIGKILL, current, 0);
+			return error;
+		}
+		
+ 		error = do_mmap(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);
+		sys_close(fd);
+		if (error != N_DATADDR(ex)) {
+			send_sig(SIGKILL, current, 0);
+			return error;
+		}
+	}
+beyond_if:
+	if (current->exec_domain && current->exec_domain->use_count)
+		(*current->exec_domain->use_count)--;
+	if (current->binfmt && current->binfmt->use_count)
+		(*current->binfmt->use_count)--;
+	current->exec_domain = lookup_exec_domain(current->personality);
+	current->binfmt = &aout_format;
+	if (current->exec_domain && current->exec_domain->use_count)
+		(*current->exec_domain->use_count)++;
+	if (current->binfmt && current->binfmt->use_count)
+		(*current->binfmt->use_count)++;
+
+	set_brk(current->mm->start_brk, current->mm->brk);
+
+	fd_offset = setup_arg_pages(ex.a_text,bprm->page) - MAX_ARG_PAGES*PAGE_SIZE;
+	p += fd_offset;
+	if (bprm->loader)
+		bprm->loader += fd_offset;
+	bprm->exec += fd_offset;
+	
+	p = (unsigned long)create_tables((char *)p, bprm,
+					current->personality != PER_LINUX);
+	current->mm->start_stack = p;
+#ifdef __alpha__
+	regs->gp = ex.a_gpvalue;
+#endif
+	start_thread(regs, ex.a_entry, p);
+	if (current->flags & PF_PTRACED)
+		send_sig(SIGTRAP, current, 0);
+	return 0;
+}
+
+static int
+load_aout_binary(struct linux_binprm * bprm, struct pt_regs * regs)
+{
+	int retval;
+
+	MOD_INC_USE_COUNT;
+	retval = do_load_aout_binary(bprm, regs);
+	MOD_DEC_USE_COUNT;
+	return retval;
+}
+
+static inline int
+do_load_aout_library(int fd)
+{
+        struct file * file;
+	struct exec ex;
+	struct  inode * inode;
+	unsigned int len;
+	unsigned int bss;
+	unsigned int start_addr;
+	unsigned long error;
+	
+	file = current->files->fd[fd];
+	inode = file->f_inode;
+	
+	if (!file || !file->f_op)
+		return -EACCES;
+
+	/* Seek into the file */
+	if (file->f_op->lseek) {
+		if ((error = file->f_op->lseek(inode, file, 0, 0)) != 0)
+			return -ENOEXEC;
+	} else
+		file->f_pos = 0;
+
+	set_fs(KERNEL_DS);
+	error = file->f_op->read(inode, file, (char *) &ex, sizeof(ex));
+	set_fs(USER_DS);
+	if (error != sizeof(ex))
+		return -ENOEXEC;
+
+	/* 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)) {
+		return -ENOEXEC;
+	}
+	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");
+		return -ENOEXEC;
+	}
+	
+	if (N_FLAGS(ex)) return -ENOEXEC;
+
+	/* 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. */
+	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));
+	if (error != start_addr)
+		return error;
+	len = PAGE_ALIGN(ex.a_text + ex.a_data);
+	bss = ex.a_text + ex.a_data + ex.a_bss;
+	if (bss > len)
+		do_mmap(NULL, start_addr + len, bss-len,
+			PROT_READ|PROT_WRITE|PROT_EXEC,
+			MAP_PRIVATE|MAP_FIXED, 0);
+	return 0;
+}
+
+static int
+load_aout_library(int fd)
+{
+	int retval;
+
+	MOD_INC_USE_COUNT;
+	retval = do_load_aout_library(fd);
+	MOD_DEC_USE_COUNT;
+	return retval;
+}
+
+
+int init_aout_binfmt(void) {
+	return register_binfmt(&aout_format);
+}
+
+#ifdef MODULE
+int init_module(void) {
+	return init_aout_binfmt();
+}
+
+void cleanup_module( void) {
+	unregister_binfmt(&aout_format);
+}
+#endif
+