1 files changed, 327 insertions, 0 deletions
diff --git a/arch/x86/ia32/ia32_aout.c b/arch/x86/ia32/ia32_aout.c
new file mode 100644
index 000000000..a09fc37ea
--- /dev/null
+++ b/arch/x86/ia32/ia32_aout.c
@@ -0,0 +1,327 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  a.out loader for x86-64
+ *
+ *  Copyright (C) 1991, 1992, 1996  Linus Torvalds
+ *  Hacked together by Andi Kleen
+ */
+
+#include <linux/module.h>
+
+#include <linux/time.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/binfmts.h>
+#include <linux/personality.h>
+#include <linux/init.h>
+#include <linux/jiffies.h>
+#include <linux/perf_event.h>
+#include <linux/sched/task_stack.h>
+
+#include <linux/uaccess.h>
+#include <asm/cacheflush.h>
+#include <asm/user32.h>
+#include <asm/ia32.h>
+
+#undef WARN_OLD
+
+static int load_aout_binary(struct linux_binprm *);
+static int load_aout_library(struct file *);
+
+static struct linux_binfmt aout_format = {
+	.module		= THIS_MODULE,
+	.load_binary	= load_aout_binary,
+	.load_shlib	= load_aout_library,
+};
+
+static int set_brk(unsigned long start, unsigned long end)
+{
+	start = PAGE_ALIGN(start);
+	end = PAGE_ALIGN(end);
+	if (end <= start)
+		return 0;
+	return vm_brk(start, end - start);
+}
+
+
+/*
+ * create_aout_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_aout_tables(char __user *p, struct linux_binprm *bprm)
+{
+	u32 __user *argv, *envp, *sp;
+	int argc = bprm->argc, envc = bprm->envc;
+
+	sp = (u32 __user *) ((-(unsigned long)sizeof(u32)) & (unsigned long) p);
+	sp -= envc+1;
+	envp = sp;
+	sp -= argc+1;
+	argv = sp;
+	put_user((unsigned long) envp, --sp);
+	put_user((unsigned long) 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(0, 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(0, 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_aout_binary(struct linux_binprm *bprm)
+{
+	unsigned long error, fd_offset, rlim;
+	struct pt_regs *regs = current_pt_regs();
+	struct exec ex;
+	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) ||
+	    i_size_read(file_inode(bprm->file)) <
+	    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 = rlimit(RLIMIT_DATA);
+	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 = begin_new_exec(bprm);
+	if (retval)
+		return retval;
+
+	/* OK, This is the point of no return */
+	set_personality(PER_LINUX);
+	set_personality_ia32(false);
+
+	setup_new_exec(bprm);
+
+	regs->cs = __USER32_CS;
+	regs->r8 = regs->r9 = regs->r10 = regs->r11 = regs->r12 =
+		regs->r13 = regs->r14 = regs->r15 = 0;
+
+	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));
+
+	retval = setup_arg_pages(bprm, IA32_STACK_TOP, EXSTACK_DEFAULT);
+	if (retval < 0)
+		return retval;
+
+	if (N_MAGIC(ex) == OMAGIC) {
+		unsigned long text_addr, map_size;
+
+		text_addr = N_TXTADDR(ex);
+		map_size = ex.a_text+ex.a_data;
+
+		error = vm_brk(text_addr & PAGE_MASK, map_size);
+
+		if (error)
+			return error;
+
+		error = read_code(bprm->file, text_addr, 32,
+				  ex.a_text + ex.a_data);
+		if ((signed long)error < 0)
+			return error;
+	} else {
+#ifdef WARN_OLD
+		static unsigned long error_time, error_time2;
+		if ((ex.a_text & 0xfff || ex.a_data & 0xfff) &&
+		    (N_MAGIC(ex) != NMAGIC) &&
+				time_after(jiffies, error_time2 + 5*HZ)) {
+			printk(KERN_NOTICE "executable not page aligned\n");
+			error_time2 = jiffies;
+		}
+
+		if ((fd_offset & ~PAGE_MASK) != 0 &&
+			    time_after(jiffies, error_time + 5*HZ)) {
+			printk(KERN_WARNING
+			       "fd_offset is not page aligned. Please convert "
+			       "program: %pD\n",
+			       bprm->file);
+			error_time = jiffies;
+		}
+#endif
+
+		if (!bprm->file->f_op->mmap || (fd_offset & ~PAGE_MASK) != 0) {
+			error = vm_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
+			if (error)
+				return error;
+
+			read_code(bprm->file, N_TXTADDR(ex), fd_offset,
+					ex.a_text+ex.a_data);
+			goto beyond_if;
+		}
+
+		error = vm_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
+				PROT_READ | PROT_EXEC,
+				MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE |
+				MAP_EXECUTABLE | MAP_32BIT,
+				fd_offset);
+
+		if (error != N_TXTADDR(ex))
+			return error;
+
+		error = vm_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
+				PROT_READ | PROT_WRITE | PROT_EXEC,
+				MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE |
+				MAP_EXECUTABLE | MAP_32BIT,
+				fd_offset + ex.a_text);
+		if (error != N_DATADDR(ex))
+			return error;
+	}
+
+beyond_if:
+	error = set_brk(current->mm->start_brk, current->mm->brk);
+	if (error)
+		return error;
+
+	set_binfmt(&aout_format);
+
+	current->mm->start_stack =
+		(unsigned long)create_aout_tables((char __user *)bprm->p, bprm);
+	/* start thread */
+	loadsegment(fs, 0);
+	loadsegment(ds, __USER32_DS);
+	loadsegment(es, __USER32_DS);
+	load_gs_index(0);
+	(regs)->ip = ex.a_entry;
+	(regs)->sp = current->mm->start_stack;
+	(regs)->flags = 0x200;
+	(regs)->cs = __USER32_CS;
+	(regs)->ss = __USER32_DS;
+	regs->r8 = regs->r9 = regs->r10 = regs->r11 =
+	regs->r12 = regs->r13 = regs->r14 = regs->r15 = 0;
+	return 0;
+}
+
+static int load_aout_library(struct file *file)
+{
+	unsigned long bss, start_addr, len, error;
+	int retval;
+	struct exec ex;
+	loff_t pos = 0;
+
+	retval = -ENOEXEC;
+	error = kernel_read(file, &ex, sizeof(ex), &pos);
+	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) ||
+	    i_size_read(file_inode(file)) <
+	    ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
+		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;
+
+	if ((N_TXTOFF(ex) & ~PAGE_MASK) != 0) {
+#ifdef WARN_OLD
+		static unsigned long error_time;
+		if (time_after(jiffies, error_time + 5*HZ)) {
+			printk(KERN_WARNING
+			       "N_TXTOFF is not page aligned. Please convert "
+			       "library: %pD\n",
+			       file);
+			error_time = jiffies;
+		}
+#endif
+		retval = vm_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
+		if (retval)
+			goto out;
+
+		read_code(file, start_addr, N_TXTOFF(ex),
+			  ex.a_text + ex.a_data);
+		retval = 0;
+		goto out;
+	}
+	/* Now use mmap to map the library into memory. */
+	error = vm_mmap(file, start_addr, ex.a_text + ex.a_data,
+			PROT_READ | PROT_WRITE | PROT_EXEC,
+			MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_32BIT,
+			N_TXTOFF(ex));
+	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) {
+		retval = vm_brk(start_addr + len, bss - len);
+		if (retval)
+			goto out;
+	}
+	retval = 0;
+out:
+	return retval;
+}
+
+static int __init init_aout_binfmt(void)
+{
+	register_binfmt(&aout_format);
+	return 0;
+}
+
+static void __exit exit_aout_binfmt(void)
+{
+	unregister_binfmt(&aout_format);
+}
+
+module_init(init_aout_binfmt);
+module_exit(exit_aout_binfmt);
+MODULE_LICENSE("GPL");