linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
* [patch] removes MAX_ARG_PAGES
@ 2007-05-06  8:51 Ollie Wild
  2007-05-07 17:46 ` Luck, Tony
  2007-05-09 20:48 ` Andrew Morton
  0 siblings, 2 replies; 11+ messages in thread
From: Ollie Wild @ 2007-05-06  8:51 UTC (permalink / raw)
  To: Peter Zijlstra, linux-kernel, parisc-linux, linux-mm, linux-arch,
	Andrew Morton, Ingo Molnar, Andi Kleen

[-- Attachment #1: Type: text/plain, Size: 903 bytes --]

A while back, I sent out a preliminary patch
(http://thread.gmane.org/gmane.linux.ports.hppa/752) to remove the
MAX_ARG_PAGES limit on command line sizes.  Since then, Peter Zijlstra
and I have fixed a number of bugs and addressed the various
outstanding issues.

The attached patch incorporates the following changes:

- Fixes a BUG_ON() assertion failure discovered by Ingo Molnar.
- Adds CONFIG_STACK_GROWSUP (parisc) support.
- Adds auditing support.
- Reverts to the old behavior on architectures with no MMU.
- Fixes broken execution of 64-bit binaries from 32-bit binaries.
- Adds elf_fdpic support.
- Fixes cache coherency bugs.

We've tested the following architectures: i386, x86_64, um/i386,
parisc, and frv.  These are representative of the various scenarios
which this patch addresses, but other architecture teams should try it
out to make sure there aren't any unexpected gotchas.

Ollie

[-- Attachment #2: no_MAX_ARG_PAGES.patch --]
[-- Type: text/x-patch, Size: 47061 bytes --]

diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index 26f15c4..022043e 100644
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -60,8 +60,6 @@ int handle_page_fault(unsigned long address, unsigned long ip,
 		goto good_area;
 	else if(!(vma->vm_flags & VM_GROWSDOWN))
 		goto out;
-	else if(is_user && !ARCH_IS_STACKGROW(address))
-		goto out;
 	else if(expand_stack(vma, address))
 		goto out;
 
diff --git a/arch/x86_64/ia32/ia32_binfmt.c b/arch/x86_64/ia32/ia32_binfmt.c
index 185399b..a2731fc 100644
--- a/arch/x86_64/ia32/ia32_binfmt.c
+++ b/arch/x86_64/ia32/ia32_binfmt.c
@@ -232,9 +232,6 @@ do {							\
 #define load_elf_binary load_elf32_binary
 
 #define ELF_PLAT_INIT(r, load_addr)	elf32_init(r)
-#define setup_arg_pages(bprm, stack_top, exec_stack) \
-	ia32_setup_arg_pages(bprm, stack_top, exec_stack)
-int ia32_setup_arg_pages(struct linux_binprm *bprm, unsigned long stack_top, int executable_stack);
 
 #undef start_thread
 #define start_thread(regs,new_rip,new_rsp) do { \
@@ -289,55 +286,7 @@ static void elf32_init(struct pt_regs *regs)
 int ia32_setup_arg_pages(struct linux_binprm *bprm, unsigned long stack_top,
 			 int executable_stack)
 {
-	unsigned long stack_base;
-	struct vm_area_struct *mpnt;
-	struct mm_struct *mm = current->mm;
-	int i, ret;
-
-	stack_base = stack_top - MAX_ARG_PAGES * PAGE_SIZE;
-	mm->arg_start = bprm->p + stack_base;
-
-	bprm->p += stack_base;
-	if (bprm->loader)
-		bprm->loader += stack_base;
-	bprm->exec += stack_base;
-
-	mpnt = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
-	if (!mpnt) 
-		return -ENOMEM; 
-
-	down_write(&mm->mmap_sem);
-	{
-		mpnt->vm_mm = mm;
-		mpnt->vm_start = PAGE_MASK & (unsigned long) bprm->p;
-		mpnt->vm_end = stack_top;
-		if (executable_stack == EXSTACK_ENABLE_X)
-			mpnt->vm_flags = VM_STACK_FLAGS |  VM_EXEC;
-		else if (executable_stack == EXSTACK_DISABLE_X)
-			mpnt->vm_flags = VM_STACK_FLAGS & ~VM_EXEC;
-		else
-			mpnt->vm_flags = VM_STACK_FLAGS;
- 		mpnt->vm_page_prot = (mpnt->vm_flags & VM_EXEC) ? 
- 			PAGE_COPY_EXEC : PAGE_COPY;
-		if ((ret = insert_vm_struct(mm, mpnt))) {
-			up_write(&mm->mmap_sem);
-			kmem_cache_free(vm_area_cachep, mpnt);
-			return ret;
-		}
-		mm->stack_vm = mm->total_vm = vma_pages(mpnt);
-	} 
-
-	for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
-		struct page *page = bprm->page[i];
-		if (page) {
-			bprm->page[i] = NULL;
-			install_arg_page(mpnt, page, stack_base);
-		}
-		stack_base += PAGE_SIZE;
-	}
-	up_write(&mm->mmap_sem);
-	
-	return 0;
+	return setup_arg_pages(bprm, stack_top, executable_stack);
 }
 EXPORT_SYMBOL(ia32_setup_arg_pages);
 
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 9cc4f0a..fa0cf77 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -254,8 +254,8 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
 		size_t len;
 		if (__put_user((elf_addr_t)p, argv++))
 			return -EFAULT;
-		len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
-		if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
+		len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
+		if (!len || len > MAX_ARG_STRLEN)
 			return 0;
 		p += len;
 	}
@@ -266,8 +266,8 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
 		size_t len;
 		if (__put_user((elf_addr_t)p, envp++))
 			return -EFAULT;
-		len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
-		if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
+		len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
+		if (!len || len > MAX_ARG_STRLEN)
 			return 0;
 		p += len;
 	}
@@ -777,10 +777,6 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
 	}
 
 	/* OK, This is the point of no return */
-	current->mm->start_data = 0;
-	current->mm->end_data = 0;
-	current->mm->end_code = 0;
-	current->mm->mmap = NULL;
 	current->flags &= ~PF_FORKNOEXEC;
 	current->mm->def_flags = def_flags;
 
@@ -985,9 +981,13 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
 
 	compute_creds(bprm);
 	current->flags &= ~PF_FORKNOEXEC;
-	create_elf_tables(bprm, &loc->elf_ex,
+	retval = create_elf_tables(bprm, &loc->elf_ex,
 			  (interpreter_type == INTERPRETER_AOUT),
 			  load_addr, interp_load_addr);
+	if (retval < 0) {
+		send_sig(SIGSEGV, current, 0);
+		goto out;
+	}
 	/* N.B. passed_fileno might not be initialized? */
 	if (interpreter_type == INTERPRETER_AOUT)
 		current->mm->arg_start += strlen(passed_fileno) + 1;
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index f3ddca4..f3dc3ca 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -622,8 +622,8 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
 	p = (char __user *) current->mm->arg_start;
 	for (loop = bprm->argc; loop > 0; loop--) {
 		__put_user((elf_caddr_t) p, argv++);
-		len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES);
-		if (!len || len > PAGE_SIZE * MAX_ARG_PAGES)
+		len = strnlen_user(p, MAX_ARG_STRLEN);
+		if (!len || len > MAX_ARG_STRLEN)
 			return -EINVAL;
 		p += len;
 	}
@@ -634,8 +634,8 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
 	current->mm->env_start = (unsigned long) p;
 	for (loop = bprm->envc; loop > 0; loop--) {
 		__put_user((elf_caddr_t)(unsigned long) p, envp++);
-		len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES);
-		if (!len || len > PAGE_SIZE * MAX_ARG_PAGES)
+		len = strnlen_user(p, MAX_ARG_STRLEN);
+		if (!len || len > MAX_ARG_STRLEN)
 			return -EINVAL;
 		p += len;
 	}
diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
index e6f5799..aa9ae99 100644
--- a/fs/binfmt_misc.c
+++ b/fs/binfmt_misc.c
@@ -126,7 +126,9 @@ static int load_misc_binary(struct linux_binprm *bprm, struct pt_regs *regs)
 		goto _ret;
 
 	if (!(fmt->flags & MISC_FMT_PRESERVE_ARGV0)) {
-		remove_arg_zero(bprm);
+		retval = remove_arg_zero(bprm);
+		if (retval)
+			goto _ret;
 	}
 
 	if (fmt->flags & MISC_FMT_OPEN_BINARY) {
diff --git a/fs/binfmt_script.c b/fs/binfmt_script.c
index 1edbcca..5b6309f 100644
--- a/fs/binfmt_script.c
+++ b/fs/binfmt_script.c
@@ -68,7 +68,9 @@ static int load_script(struct linux_binprm *bprm,struct pt_regs *regs)
 	 * This is done in reverse order, because of how the
 	 * user environment and arguments are stored.
 	 */
-	remove_arg_zero(bprm);
+	retval = remove_arg_zero(bprm);
+	if (retval)
+		return retval;
 	retval = copy_strings_kernel(1, &bprm->interp, bprm);
 	if (retval < 0) return retval; 
 	bprm->argc++;
diff --git a/fs/compat.c b/fs/compat.c
index 72e5e69..5279745 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -1391,6 +1391,7 @@ static int compat_copy_strings(int argc, compat_uptr_t __user *argv,
 {
 	struct page *kmapped_page = NULL;
 	char *kaddr = NULL;
+	unsigned long kpos = 0;
 	int ret;
 
 	while (argc-- > 0) {
@@ -1399,92 +1400,84 @@ static int compat_copy_strings(int argc, compat_uptr_t __user *argv,
 		unsigned long pos;
 
 		if (get_user(str, argv+argc) ||
-			!(len = strnlen_user(compat_ptr(str), bprm->p))) {
+		    !(len = strnlen_user(compat_ptr(str), MAX_ARG_STRLEN))) {
 			ret = -EFAULT;
 			goto out;
 		}
 
-		if (bprm->p < len)  {
+		if (MAX_ARG_STRLEN < len) {
 			ret = -E2BIG;
 			goto out;
 		}
 
-		bprm->p -= len;
-		/* XXX: add architecture specific overflow check here. */
+		/* We're going to work our way backwords. */
 		pos = bprm->p;
+		str += len;
+		bprm->p -= len;
 
 		while (len > 0) {
-			int i, new, err;
 			int offset, bytes_to_copy;
-			struct page *page;
 
 			offset = pos % PAGE_SIZE;
-			i = pos/PAGE_SIZE;
-			page = bprm->page[i];
-			new = 0;
-			if (!page) {
-				page = alloc_page(GFP_HIGHUSER);
-				bprm->page[i] = page;
-				if (!page) {
-					ret = -ENOMEM;
+			if (offset == 0)
+				offset = PAGE_SIZE;
+
+			bytes_to_copy = offset;
+			if (bytes_to_copy > len)
+				bytes_to_copy = len;
+
+			offset -= bytes_to_copy;
+			pos -= bytes_to_copy;
+			str -= bytes_to_copy;
+			len -= bytes_to_copy;
+
+			if (!kmapped_page || kpos != (pos & PAGE_MASK)) {
+				struct page *page;
+
+#ifdef CONFIG_STACK_GROWSUP
+				ret = expand_downwards(bprm->vma, pos);
+				if (ret < 0) {
+					/* We've exceed the stack rlimit. */
+					ret = -E2BIG;
+					goto out;
+				}
+#endif
+				ret = get_user_pages(current, bprm->mm, pos,
+						     1, 1, 1, &page, NULL);
+				if (ret <= 0) {
+					/* We've exceed the stack rlimit. */
+					ret = -E2BIG;
 					goto out;
 				}
-				new = 1;
-			}
 
-			if (page != kmapped_page) {
-				if (kmapped_page)
+				if (kmapped_page) {
+					flush_kernel_dcache_page(kmapped_page);
 					kunmap(kmapped_page);
+					put_page(kmapped_page);
+				}
 				kmapped_page = page;
 				kaddr = kmap(kmapped_page);
+				kpos = pos & PAGE_MASK;
+				flush_cache_page(bprm->vma, kpos,
+						 page_to_pfn(kmapped_page));
 			}
-			if (new && offset)
-				memset(kaddr, 0, offset);
-			bytes_to_copy = PAGE_SIZE - offset;
-			if (bytes_to_copy > len) {
-				bytes_to_copy = len;
-				if (new)
-					memset(kaddr+offset+len, 0,
-						PAGE_SIZE-offset-len);
-			}
-			err = copy_from_user(kaddr+offset, compat_ptr(str),
-						bytes_to_copy);
-			if (err) {
+			if (copy_from_user(kaddr+offset, compat_ptr(str),
+						bytes_to_copy)) {
 				ret = -EFAULT;
 				goto out;
 			}
-
-			pos += bytes_to_copy;
-			str += bytes_to_copy;
-			len -= bytes_to_copy;
 		}
 	}
 	ret = 0;
 out:
-	if (kmapped_page)
+	if (kmapped_page) {
+		flush_kernel_dcache_page(kmapped_page);
 		kunmap(kmapped_page);
-	return ret;
-}
-
-#ifdef CONFIG_MMU
-
-#define free_arg_pages(bprm) do { } while (0)
-
-#else
-
-static inline void free_arg_pages(struct linux_binprm *bprm)
-{
-	int i;
-
-	for (i = 0; i < MAX_ARG_PAGES; i++) {
-		if (bprm->page[i])
-			__free_page(bprm->page[i]);
-		bprm->page[i] = NULL;
+		put_page(kmapped_page);
 	}
+	return ret;
 }
 
-#endif /* CONFIG_MMU */
-
 /*
  * compat_do_execve() is mostly a copy of do_execve(), with the exception
  * that it processes 32 bit argv and envp pointers.
@@ -1497,7 +1490,6 @@ int compat_do_execve(char * filename,
 	struct linux_binprm *bprm;
 	struct file *file;
 	int retval;
-	int i;
 
 	retval = -ENOMEM;
 	bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
@@ -1511,24 +1503,19 @@ int compat_do_execve(char * filename,
 
 	sched_exec();
 
-	bprm->p = PAGE_SIZE*MAX_ARG_PAGES-sizeof(void *);
 	bprm->file = file;
 	bprm->filename = filename;
 	bprm->interp = filename;
-	bprm->mm = mm_alloc();
-	retval = -ENOMEM;
-	if (!bprm->mm)
-		goto out_file;
 
-	retval = init_new_context(current, bprm->mm);
-	if (retval < 0)
-		goto out_mm;
+	retval = bprm_mm_init(bprm);
+	if (retval)
+		goto out_file;
 
-	bprm->argc = compat_count(argv, bprm->p / sizeof(compat_uptr_t));
+	bprm->argc = compat_count(argv, MAX_ARG_STRINGS);
 	if ((retval = bprm->argc) < 0)
 		goto out_mm;
 
-	bprm->envc = compat_count(envp, bprm->p / sizeof(compat_uptr_t));
+	bprm->envc = compat_count(envp, MAX_ARG_STRINGS);
 	if ((retval = bprm->envc) < 0)
 		goto out_mm;
 
@@ -1553,10 +1540,8 @@ int compat_do_execve(char * filename,
 	if (retval < 0)
 		goto out;
 
-	retval = search_binary_handler(bprm, regs);
+	retval = search_binary_handler(bprm,regs);
 	if (retval >= 0) {
-		free_arg_pages(bprm);
-
 		/* execve success */
 		security_bprm_free(bprm);
 		acct_update_integrals(current);
@@ -1565,19 +1550,12 @@ int compat_do_execve(char * filename,
 	}
 
 out:
-	/* Something went wrong, return the inode and free the argument pages*/
-	for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
-		struct page * page = bprm->page[i];
-		if (page)
-			__free_page(page);
-	}
-
 	if (bprm->security)
 		security_bprm_free(bprm);
 
 out_mm:
 	if (bprm->mm)
-		mmdrop(bprm->mm);
+		mmput (bprm->mm);
 
 out_file:
 	if (bprm->file) {
diff --git a/fs/exec.c b/fs/exec.c
index 3155e91..8637630 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -53,6 +53,7 @@
 
 #include <asm/uaccess.h>
 #include <asm/mmu_context.h>
+#include <asm/tlb.h>
 
 #ifdef CONFIG_KMOD
 #include <linux/kmod.h>
@@ -173,6 +174,153 @@ exit:
 	goto out;
 }
 
+#ifdef CONFIG_MMU
+
+static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,
+		int write)
+{
+	struct page *page;
+	int ret;
+
+#ifdef CONFIG_STACK_GROWSUP
+	if (write) {
+		ret = expand_downwards(bprm->vma, pos);
+		if (ret < 0)
+			return NULL;
+	}
+#endif
+	ret = get_user_pages(current, bprm->mm, pos,
+			1, write, 1, &page, NULL);
+	if (ret <= 0)
+		return NULL;
+
+	return page;
+}
+
+static void put_arg_page(struct page *page)
+{
+	put_page(page);
+}
+
+static void free_arg_page(struct linux_binprm *bprm, int i)
+{
+}
+
+static void free_arg_pages(struct linux_binprm *bprm)
+{
+}
+
+#else
+
+static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,
+		int write)
+{
+	struct page *page;
+
+	page = bprm->page[pos / PAGE_SIZE];
+	if (!page && write) {
+		page = alloc_page(GFP_HIGHUSER|__GFP_ZERO);
+		if (!page)
+			return NULL;
+		bprm->page[pos / PAGE_SIZE] = page;
+	}
+
+	return page;
+}
+
+static void put_arg_page(struct page *page)
+{
+}
+
+static void free_arg_page(struct linux_binprm *bprm, int i)
+{
+	if (bprm->page[i]) {
+		__free_page(bprm->page[i]);
+		bprm->page[i] = NULL;
+	}
+}
+
+static void free_arg_pages(struct linux_binprm *bprm)
+{
+	int i;
+
+	for (i = 0; i < MAX_ARG_PAGES; i++)
+		free_arg_page(bprm, i);
+}
+
+#endif /* CONFIG_MMU */
+
+/* Create a new mm_struct and populate it with a temporary stack
+ * vm_area_struct.  We don't have enough context at this point to set the
+ * stack flags, permissions, and offset, so we use temporary values.  We'll
+ * update them later in setup_arg_pages(). */
+int bprm_mm_init(struct linux_binprm *bprm)
+{
+	int err;
+	struct mm_struct *mm = NULL;
+	struct vm_area_struct *vma = NULL;
+
+	bprm->mm = mm = mm_alloc();
+	err = -ENOMEM;
+	if (!mm)
+		goto err;
+
+	if ((err = init_new_context(current, mm)))
+		goto err;
+
+#ifdef CONFIG_MMU
+	bprm->vma = vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
+	err = -ENOMEM;
+	if (!vma)
+		goto err;
+
+	down_write(&mm->mmap_sem);
+	{
+		vma->vm_mm = mm;
+
+		/* Place the stack at the top of user memory.  Later, we'll
+		 * move this to an appropriate place.  We don't use STACK_TOP
+		 * because that can depend on attributes which aren't
+		 * configured yet. */
+		vma->vm_end = TASK_SIZE;
+		vma->vm_start = vma->vm_end - PAGE_SIZE;
+
+		vma->vm_flags = VM_STACK_FLAGS;
+		vma->vm_page_prot = protection_map[vma->vm_flags & 0x7];
+		if ((err = insert_vm_struct(mm, vma))) {
+			up_write(&mm->mmap_sem);
+			goto err;
+		}
+
+		mm->stack_vm = mm->total_vm = 1;
+	}
+	up_write(&mm->mmap_sem);
+
+	bprm->p = vma->vm_end - sizeof(void *);
+#else
+	bprm->p = PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *);
+#endif
+
+	return 0;
+
+err:
+#ifdef CONFIG_MMU
+	if (vma) {
+		bprm->vma = NULL;
+		kmem_cache_free(vm_area_cachep, vma);
+	}
+#endif
+
+	if (mm) {
+		bprm->mm = NULL;
+		mmdrop(mm);
+	}
+
+	return err;
+}
+
+EXPORT_SYMBOL(bprm_mm_init);
+
 /*
  * count() counts the number of strings in array ARGV.
  */
@@ -198,15 +346,16 @@ static int count(char __user * __user * argv, int max)
 }
 
 /*
- * 'copy_strings()' copies argument/environment strings from user
- * memory to free pages in kernel mem. These are in a format ready
- * to be put directly into the top of new user memory.
+ * 'copy_strings()' copies argument/environment strings from the old
+ * processes's memory to the new process's stack.  The call to get_user_pages()
+ * ensures the destination page is created and not swapped out.
  */
 static int copy_strings(int argc, char __user * __user * argv,
 			struct linux_binprm *bprm)
 {
 	struct page *kmapped_page = NULL;
 	char *kaddr = NULL;
+	unsigned long kpos = 0;
 	int ret;
 
 	while (argc-- > 0) {
@@ -215,69 +364,77 @@ static int copy_strings(int argc, char __user * __user * argv,
 		unsigned long pos;
 
 		if (get_user(str, argv+argc) ||
-				!(len = strnlen_user(str, bprm->p))) {
+				!(len = strnlen_user(str, MAX_ARG_STRLEN))) {
 			ret = -EFAULT;
 			goto out;
 		}
 
-		if (bprm->p < len)  {
+#ifdef CONFIG_MMU
+		if (MAX_ARG_STRLEN < len) {
 			ret = -E2BIG;
 			goto out;
 		}
+#else
+		if (bprm->p < len) {
+			ret = -E2BIG;
+			goto out;
+		}
+#endif
 
-		bprm->p -= len;
-		/* XXX: add architecture specific overflow check here. */
+		/* We're going to work our way backwords. */
 		pos = bprm->p;
+		str += len;
+		bprm->p -= len;
 
 		while (len > 0) {
-			int i, new, err;
 			int offset, bytes_to_copy;
-			struct page *page;
 
 			offset = pos % PAGE_SIZE;
-			i = pos/PAGE_SIZE;
-			page = bprm->page[i];
-			new = 0;
-			if (!page) {
-				page = alloc_page(GFP_HIGHUSER);
-				bprm->page[i] = page;
+			if (offset == 0)
+				offset = PAGE_SIZE;
+
+			bytes_to_copy = offset;
+			if (bytes_to_copy > len)
+				bytes_to_copy = len;
+
+			offset -= bytes_to_copy;
+			pos -= bytes_to_copy;
+			str -= bytes_to_copy;
+			len -= bytes_to_copy;
+
+			if (!kmapped_page || kpos != (pos & PAGE_MASK)) {
+				struct page *page;
+
+				page = get_arg_page(bprm, pos, 1);
 				if (!page) {
-					ret = -ENOMEM;
+					ret = -E2BIG;
 					goto out;
 				}
-				new = 1;
-			}
 
-			if (page != kmapped_page) {
-				if (kmapped_page)
+				if (kmapped_page) {
+					flush_kernel_dcache_page(kmapped_page);
 					kunmap(kmapped_page);
+					put_arg_page(kmapped_page);
+				}
 				kmapped_page = page;
 				kaddr = kmap(kmapped_page);
+				kpos = pos & PAGE_MASK;
+				flush_cache_page(bprm->vma, kpos,
+						 page_to_pfn(kmapped_page));
 			}
-			if (new && offset)
-				memset(kaddr, 0, offset);
-			bytes_to_copy = PAGE_SIZE - offset;
-			if (bytes_to_copy > len) {
-				bytes_to_copy = len;
-				if (new)
-					memset(kaddr+offset+len, 0,
-						PAGE_SIZE-offset-len);
-			}
-			err = copy_from_user(kaddr+offset, str, bytes_to_copy);
-			if (err) {
+			if (copy_from_user(kaddr+offset, str, bytes_to_copy)) {
 				ret = -EFAULT;
 				goto out;
 			}
-
-			pos += bytes_to_copy;
-			str += bytes_to_copy;
-			len -= bytes_to_copy;
 		}
 	}
 	ret = 0;
 out:
-	if (kmapped_page)
+	if (kmapped_page) {
+		flush_kernel_dcache_page(kmapped_page);
 		kunmap(kmapped_page);
+		put_arg_page(kmapped_page);
+	}
 	return ret;
 }
 
@@ -297,154 +454,157 @@ int copy_strings_kernel(int argc,char ** argv, struct linux_binprm *bprm)
 EXPORT_SYMBOL(copy_strings_kernel);
 
 #ifdef CONFIG_MMU
-/*
- * This routine is used to map in a page into an address space: needed by
- * execve() for the initial stack and environment pages.
- *
- * vma->vm_mm->mmap_sem is held for writing.
- */
-void install_arg_page(struct vm_area_struct *vma,
-			struct page *page, unsigned long address)
+
+static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift)
 {
 	struct mm_struct *mm = vma->vm_mm;
-	pte_t * pte;
-	spinlock_t *ptl;
+	unsigned long old_start = vma->vm_start;
+	unsigned long old_end = vma->vm_end;
+	unsigned long length = old_end - old_start;
+	unsigned long new_start = old_start + shift;
+	unsigned long new_end = old_end + shift;
+	struct mmu_gather *tlb;
+
+	BUG_ON(new_start > new_end);
+
+	if (new_start < old_start) {
+		if (vma != find_vma(mm, new_start))
+			return -EFAULT;
+
+		vma_adjust(vma, new_start, old_end,
+			   vma->vm_pgoff - (-shift >> PAGE_SHIFT), NULL);
+
+		if (length != move_page_tables(vma, old_start,
+					       vma, new_start, length))
+			return -ENOMEM;
+		
+		lru_add_drain();
+		tlb = tlb_gather_mmu(mm, 0);
+		free_pgd_range(&tlb, new_end, old_end, new_end,
+			       vma->vm_next ? vma->vm_next->vm_start : 0);
+		tlb_finish_mmu(tlb, new_end, old_end);
+
+		vma_adjust(vma, new_start, new_end, vma->vm_pgoff, NULL);
+	} else {
+		struct vm_area_struct *tmp, *prev;
+		
+		tmp = find_vma_prev(mm, new_end, &prev);
+		if ((tmp && tmp->vm_start < new_end) || prev != vma)
+			return -EFAULT;
 
-	if (unlikely(anon_vma_prepare(vma)))
-		goto out;
+		find_vma_prev(mm, vma->vm_start, &prev);
 
-	flush_dcache_page(page);
-	pte = get_locked_pte(mm, address, &ptl);
-	if (!pte)
-		goto out;
-	if (!pte_none(*pte)) {
-		pte_unmap_unlock(pte, ptl);
-		goto out;
+		vma_adjust(vma, old_start, new_end, vma->vm_pgoff, NULL);
+
+		if (length != move_page_tables_up(vma, old_start,
+					       vma, new_start, length))
+			return -ENOMEM;
+
+		lru_add_drain();
+		tlb = tlb_gather_mmu(mm, 0);
+		free_pgd_range(&tlb, old_start, new_start, 
+			       prev ? prev->vm_end: 0, new_start);
+		tlb_finish_mmu(tlb, old_start, new_start);
+
+		vma_adjust(vma, new_start, new_end,
+			   vma->vm_pgoff + (shift >> PAGE_SHIFT), NULL);
 	}
-	inc_mm_counter(mm, anon_rss);
-	lru_cache_add_active(page);
-	set_pte_at(mm, address, pte, pte_mkdirty(pte_mkwrite(mk_pte(
-					page, vma->vm_page_prot))));
-	page_add_new_anon_rmap(page, vma, address);
-	pte_unmap_unlock(pte, ptl);
-
-	/* no need for flush_tlb */
-	return;
-out:
-	__free_page(page);
-	force_sig(SIGKILL, current);
+
+	return 0;
 }
 
 #define EXTRA_STACK_VM_PAGES	20	/* random */
 
+/* Finalizes the stack vm_area_struct.  The flags and permissions are updated,
+ * the stack is optionally relocated, and some extra space is added.
+ */
 int setup_arg_pages(struct linux_binprm *bprm,
 		    unsigned long stack_top,
 		    int executable_stack)
 {
-	unsigned long stack_base;
-	struct vm_area_struct *mpnt;
+	unsigned long ret;
+	unsigned long stack_base, stack_shift;
 	struct mm_struct *mm = current->mm;
-	int i, ret;
-	long arg_size;
+	struct vm_area_struct *vma = bprm->vma;
 
 #ifdef CONFIG_STACK_GROWSUP
-	/* Move the argument and environment strings to the bottom of the
-	 * stack space.
-	 */
-	int offset, j;
-	char *to, *from;
-
-	/* Start by shifting all the pages down */
-	i = 0;
-	for (j = 0; j < MAX_ARG_PAGES; j++) {
-		struct page *page = bprm->page[j];
-		if (!page)
-			continue;
-		bprm->page[i++] = page;
-	}
-
-	/* Now move them within their pages */
-	offset = bprm->p % PAGE_SIZE;
-	to = kmap(bprm->page[0]);
-	for (j = 1; j < i; j++) {
-		memmove(to, to + offset, PAGE_SIZE - offset);
-		from = kmap(bprm->page[j]);
-		memcpy(to + PAGE_SIZE - offset, from, offset);
-		kunmap(bprm->page[j - 1]);
-		to = from;
-	}
-	memmove(to, to + offset, PAGE_SIZE - offset);
-	kunmap(bprm->page[j - 1]);
-
 	/* Limit stack size to 1GB */
 	stack_base = current->signal->rlim[RLIMIT_STACK].rlim_max;
 	if (stack_base > (1 << 30))
 		stack_base = 1 << 30;
 	stack_base = PAGE_ALIGN(stack_top - stack_base);
 
-	/* Adjust bprm->p to point to the end of the strings. */
-	bprm->p = stack_base + PAGE_SIZE * i - offset;
-
-	mm->arg_start = stack_base;
-	arg_size = i << PAGE_SHIFT;
+	/* Make sure we didn't let the argument array grow too large. */
+	if (vma->vm_end - vma->vm_start > STACK_TOP - stack_base)
+		return -ENOMEM;
 
-	/* zero pages that were copied above */
-	while (i < MAX_ARG_PAGES)
-		bprm->page[i++] = NULL;
+	stack_shift = stack_base - vma->vm_start;
+	mm->arg_start = bprm->p + stack_shift;
+	bprm->p = vma->vm_end + stack_shift;
 #else
-	stack_base = arch_align_stack(stack_top - MAX_ARG_PAGES*PAGE_SIZE);
+	BUG_ON(stack_top > STACK_TOP);
+	BUG_ON(stack_top & ~PAGE_MASK);
+
+	stack_base = arch_align_stack(stack_top - mm->stack_vm*PAGE_SIZE);
 	stack_base = PAGE_ALIGN(stack_base);
-	bprm->p += stack_base;
+
+	/* Make sure we didn't let the argument array grow too large. */
+	if (stack_base > stack_top)
+		return -ENOMEM;
+
+	stack_shift = stack_base - (bprm->p & PAGE_MASK);
+	bprm->p += stack_shift;
 	mm->arg_start = bprm->p;
-	arg_size = stack_top - (PAGE_MASK & (unsigned long) mm->arg_start);
 #endif
 
-	arg_size += EXTRA_STACK_VM_PAGES * PAGE_SIZE;
-
 	if (bprm->loader)
-		bprm->loader += stack_base;
-	bprm->exec += stack_base;
-
-	mpnt = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
-	if (!mpnt)
-		return -ENOMEM;
+		bprm->loader += stack_shift;
+	bprm->exec += stack_shift;
 
 	down_write(&mm->mmap_sem);
 	{
-		mpnt->vm_mm = mm;
-#ifdef CONFIG_STACK_GROWSUP
-		mpnt->vm_start = stack_base;
-		mpnt->vm_end = stack_base + arg_size;
-#else
-		mpnt->vm_end = stack_top;
-		mpnt->vm_start = mpnt->vm_end - arg_size;
-#endif
+		struct vm_area_struct *prev = NULL;
+		unsigned long vm_flags = vma->vm_flags;
+
 		/* Adjust stack execute permissions; explicitly enable
 		 * for EXSTACK_ENABLE_X, disable for EXSTACK_DISABLE_X
 		 * and leave alone (arch default) otherwise. */
 		if (unlikely(executable_stack == EXSTACK_ENABLE_X))
-			mpnt->vm_flags = VM_STACK_FLAGS |  VM_EXEC;
+			vm_flags |= VM_EXEC;
 		else if (executable_stack == EXSTACK_DISABLE_X)
-			mpnt->vm_flags = VM_STACK_FLAGS & ~VM_EXEC;
-		else
-			mpnt->vm_flags = VM_STACK_FLAGS;
-		mpnt->vm_flags |= mm->def_flags;
-		mpnt->vm_page_prot = protection_map[mpnt->vm_flags & 0x7];
-		if ((ret = insert_vm_struct(mm, mpnt))) {
+			vm_flags &= ~VM_EXEC;
+		vm_flags |= mm->def_flags;
+
+		ret = mprotect_fixup(vma, &prev, vma->vm_start, vma->vm_end,
+				vm_flags);
+		if (ret) {
 			up_write(&mm->mmap_sem);
-			kmem_cache_free(vm_area_cachep, mpnt);
 			return ret;
 		}
-		mm->stack_vm = mm->total_vm = vma_pages(mpnt);
-	}
+		BUG_ON(prev != vma);
+
+		/* Move stack pages down in memory. */
+		if (stack_shift) {
+			ret = shift_arg_pages(vma, stack_shift);
+			if (ret) {
+				up_write(&mm->mmap_sem);
+				return ret;
+			}
+		}
 
-	for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
-		struct page *page = bprm->page[i];
-		if (page) {
-			bprm->page[i] = NULL;
-			install_arg_page(mpnt, page, stack_base);
+#ifdef CONFIG_STACK_GROWSUP
+		if (expand_stack(vma, vma->vm_end +
+					EXTRA_STACK_VM_PAGES * PAGE_SIZE)) {
+			up_write(&mm->mmap_sem);
+			return -EFAULT;
+		}
+#else
+		if (expand_stack(vma, stack_base -
+					EXTRA_STACK_VM_PAGES * PAGE_SIZE)) {
+			up_write(&mm->mmap_sem);
+			return -EFAULT;
 		}
-		stack_base += PAGE_SIZE;
+#endif
 	}
 	up_write(&mm->mmap_sem);
 	
@@ -453,21 +613,6 @@ int setup_arg_pages(struct linux_binprm *bprm,
 
 EXPORT_SYMBOL(setup_arg_pages);
 
-#define free_arg_pages(bprm) do { } while (0)
-
-#else
-
-static inline void free_arg_pages(struct linux_binprm *bprm)
-{
-	int i;
-
-	for (i = 0; i < MAX_ARG_PAGES; i++) {
-		if (bprm->page[i])
-			__free_page(bprm->page[i]);
-		bprm->page[i] = NULL;
-	}
-}
-
 #endif /* CONFIG_MMU */
 
 struct file *open_exec(const char *name)
@@ -985,28 +1130,47 @@ void compute_creds(struct linux_binprm *bprm)
 
 EXPORT_SYMBOL(compute_creds);
 
-void remove_arg_zero(struct linux_binprm *bprm)
+/*
+ * Arguments are '\0' separated strings found at the location bprm->p
+ * points to; chop off the first by relocating brpm->p to right after
+ * the first '\0' encountered.
+ */
+int remove_arg_zero(struct linux_binprm *bprm)
 {
-	if (bprm->argc) {
-		unsigned long offset;
-		char * kaddr;
-		struct page *page;
+	int ret = 0;
+	unsigned long offset;
+	char *kaddr;
+	struct page *page;
 
-		offset = bprm->p % PAGE_SIZE;
-		goto inside;
+	if (!bprm->argc)
+		return 0;
 
-		while (bprm->p++, *(kaddr+offset++)) {
-			if (offset != PAGE_SIZE)
-				continue;
-			offset = 0;
-			kunmap_atomic(kaddr, KM_USER0);
-inside:
-			page = bprm->page[bprm->p/PAGE_SIZE];
-			kaddr = kmap_atomic(page, KM_USER0);
+	do {
+		offset = bprm->p & ~PAGE_MASK;
+		page = get_arg_page(bprm, bprm->p, 0);
+		if (!page) {
+			ret = -EFAULT;
+			goto out;
 		}
+		kaddr = kmap_atomic(page, KM_USER0);
+
+		for (; offset < PAGE_SIZE && kaddr[offset];
+				offset++, bprm->p++)
+			;
+
 		kunmap_atomic(kaddr, KM_USER0);
-		bprm->argc--;
-	}
+		put_arg_page(page);
+
+		if (offset == PAGE_SIZE)
+			free_arg_page(bprm, (bprm->p >> PAGE_SHIFT) - 1);
+	} while (offset == PAGE_SIZE);
+
+	bprm->p++;
+	bprm->argc--;
+	ret = 0;
+
+out:
+	return ret;
 }
 
 EXPORT_SYMBOL(remove_arg_zero);
@@ -1033,7 +1197,7 @@ int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs)
 		fput(bprm->file);
 		bprm->file = NULL;
 
-	        loader = PAGE_SIZE*MAX_ARG_PAGES-sizeof(void *);
+	        loader = bprm->vma->vm_end - sizeof(void *);
 
 		file = open_exec("/sbin/loader");
 		retval = PTR_ERR(file);
@@ -1125,8 +1289,8 @@ int do_execve(char * filename,
 {
 	struct linux_binprm *bprm;
 	struct file *file;
+	unsigned long tmp;
 	int retval;
-	int i;
 
 	retval = -ENOMEM;
 	bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
@@ -1140,25 +1304,19 @@ int do_execve(char * filename,
 
 	sched_exec();
 
-	bprm->p = PAGE_SIZE*MAX_ARG_PAGES-sizeof(void *);
-
 	bprm->file = file;
 	bprm->filename = filename;
 	bprm->interp = filename;
-	bprm->mm = mm_alloc();
-	retval = -ENOMEM;
-	if (!bprm->mm)
-		goto out_file;
 
-	retval = init_new_context(current, bprm->mm);
-	if (retval < 0)
-		goto out_mm;
+	retval = bprm_mm_init(bprm);
+	if (retval)
+		goto out_file;
 
-	bprm->argc = count(argv, bprm->p / sizeof(void *));
+	bprm->argc = count(argv, MAX_ARG_STRINGS);
 	if ((retval = bprm->argc) < 0)
 		goto out_mm;
 
-	bprm->envc = count(envp, bprm->p / sizeof(void *));
+	bprm->envc = count(envp, MAX_ARG_STRINGS);
 	if ((retval = bprm->envc) < 0)
 		goto out_mm;
 
@@ -1179,15 +1337,16 @@ int do_execve(char * filename,
 	if (retval < 0)
 		goto out;
 
+	tmp = bprm->p;
 	retval = copy_strings(bprm->argc, argv, bprm);
 	if (retval < 0)
 		goto out;
+	bprm->argv_len = tmp - bprm->p;
 
 	retval = search_binary_handler(bprm,regs);
 	if (retval >= 0) {
-		free_arg_pages(bprm);
-
 		/* execve success */
+		free_arg_pages(bprm);
 		security_bprm_free(bprm);
 		acct_update_integrals(current);
 		kfree(bprm);
@@ -1195,26 +1354,19 @@ int do_execve(char * filename,
 	}
 
 out:
-	/* Something went wrong, return the inode and free the argument pages*/
-	for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
-		struct page * page = bprm->page[i];
-		if (page)
-			__free_page(page);
-	}
-
+	free_arg_pages(bprm);
 	if (bprm->security)
 		security_bprm_free(bprm);
 
 out_mm:
 	if (bprm->mm)
-		mmdrop(bprm->mm);
+		mmput (bprm->mm);
 
 out_file:
 	if (bprm->file) {
 		allow_write_access(bprm->file);
 		fput(bprm->file);
 	}
-
 out_kfree:
 	kfree(bprm);
 
diff --git a/include/asm-um/processor-i386.h b/include/asm-um/processor-i386.h
index 595f1c3..869c236 100644
--- a/include/asm-um/processor-i386.h
+++ b/include/asm-um/processor-i386.h
@@ -67,9 +67,6 @@ static inline void rep_nop(void)
 #define current_text_addr() \
 	({ void *pc; __asm__("movl $1f,%0\n1:":"=g" (pc)); pc; })
 
-#define ARCH_IS_STACKGROW(address) \
-       (address + 32 >= UPT_SP(&current->thread.regs.regs))
-
 #define KSTK_EIP(tsk) KSTK_REG(tsk, EIP)
 #define KSTK_ESP(tsk) KSTK_REG(tsk, UESP)
 #define KSTK_EBP(tsk) KSTK_REG(tsk, EBP)
diff --git a/include/asm-um/processor-x86_64.h b/include/asm-um/processor-x86_64.h
index 31c2d4d..64d7bdd 100644
--- a/include/asm-um/processor-x86_64.h
+++ b/include/asm-um/processor-x86_64.h
@@ -44,9 +44,6 @@ static inline void arch_copy_thread(struct arch_thread *from,
 #define current_text_addr() \
 	({ void *pc; __asm__("movq $1f,%0\n1:":"=g" (pc)); pc; })
 
-#define ARCH_IS_STACKGROW(address) \
-        (address + 128 >= UPT_SP(&current->thread.regs.regs))
-
 #define KSTK_EIP(tsk) KSTK_REG(tsk, RIP)
 #define KSTK_ESP(tsk) KSTK_REG(tsk, RSP)
 
diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h
index 2d956cd..8ac2277 100644
--- a/include/linux/binfmts.h
+++ b/include/linux/binfmts.h
@@ -5,12 +5,9 @@
 
 struct pt_regs;
 
-/*
- * MAX_ARG_PAGES defines the number of pages allocated for arguments
- * and envelope for the new program. 32 should suffice, this gives
- * a maximum env+arg of 128kB w/4KB pages!
- */
-#define MAX_ARG_PAGES 32
+/* FIXME: Find real limits, or none. */
+#define MAX_ARG_STRLEN (PAGE_SIZE * 32)
+#define MAX_ARG_STRINGS 0x7FFFFFFF
 
 /* sizeof(linux_binprm->buf) */
 #define BINPRM_BUF_SIZE 128
@@ -22,7 +19,12 @@ struct pt_regs;
  */
 struct linux_binprm{
 	char buf[BINPRM_BUF_SIZE];
+#ifdef CONFIG_MMU
+	struct vm_area_struct *vma;
+#else
+# define MAX_ARG_PAGES	32
 	struct page *page[MAX_ARG_PAGES];
+#endif
 	struct mm_struct *mm;
 	unsigned long p; /* current top of mem */
 	int sh_bang;
@@ -38,6 +40,7 @@ struct linux_binprm{
 	unsigned interp_flags;
 	unsigned interp_data;
 	unsigned long loader, exec;
+	unsigned long argv_len;
 };
 
 #define BINPRM_FLAGS_ENFORCE_NONDUMP_BIT 0
@@ -66,7 +69,7 @@ extern int register_binfmt(struct linux_binfmt *);
 extern int unregister_binfmt(struct linux_binfmt *);
 
 extern int prepare_binprm(struct linux_binprm *);
-extern void remove_arg_zero(struct linux_binprm *);
+extern int __must_check remove_arg_zero(struct linux_binprm *);
 extern int search_binary_handler(struct linux_binprm *,struct pt_regs *);
 extern int flush_old_exec(struct linux_binprm * bprm);
 
@@ -83,6 +86,7 @@ extern int suid_dumpable;
 extern int setup_arg_pages(struct linux_binprm * bprm,
 			   unsigned long stack_top,
 			   int executable_stack);
+extern int bprm_mm_init(struct linux_binprm *bprm);
 extern int copy_strings_kernel(int argc,char ** argv,struct linux_binprm *bprm);
 extern void compute_creds(struct linux_binprm *binprm);
 extern int do_coredump(long signr, int exit_code, struct pt_regs * regs);
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 60e0e4a..ceee062 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -771,7 +771,6 @@ static inline int handle_mm_fault(struct mm_struct *mm,
 
 extern int make_pages_present(unsigned long addr, unsigned long end);
 extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write);
-void install_arg_page(struct vm_area_struct *, struct page *, unsigned long);
 
 int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, unsigned long start,
 		int len, int write, int force, struct page **pages, struct vm_area_struct **vmas);
@@ -788,9 +787,18 @@ int FASTCALL(set_page_dirty(struct page *page));
 int set_page_dirty_lock(struct page *page);
 int clear_page_dirty_for_io(struct page *page);
 
+extern unsigned long move_page_tables(struct vm_area_struct *vma,
+		unsigned long old_addr, struct vm_area_struct *new_vma,
+		unsigned long new_addr, unsigned long len);
+extern unsigned long move_page_tables_up(struct vm_area_struct *vma,
+		unsigned long old_addr, struct vm_area_struct *new_vma,
+		unsigned long new_addr, unsigned long len);
 extern unsigned long do_mremap(unsigned long addr,
 			       unsigned long old_len, unsigned long new_len,
 			       unsigned long flags, unsigned long new_addr);
+extern int mprotect_fixup(struct vm_area_struct *vma,
+			  struct vm_area_struct **pprev, unsigned long start,
+			  unsigned long end, unsigned long newflags);
 
 /*
  * Prototype to add a shrinker callback for ageable caches.
@@ -1091,6 +1099,9 @@ extern int expand_stack(struct vm_area_struct *vma, unsigned long address);
 #ifdef CONFIG_IA64
 extern int expand_upwards(struct vm_area_struct *vma, unsigned long address);
 #endif
+#ifdef CONFIG_STACK_GROWSUP
+extern int expand_downwards(struct vm_area_struct *vma, unsigned long address);
+#endif
 
 /* Look up the first VMA which satisfies  addr < vm_end,  NULL if none. */
 extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr);
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 47f1c53..b97ca11 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -165,6 +165,7 @@ enum
 	KERN_MAX_LOCK_DEPTH=74,
 	KERN_NMI_WATCHDOG=75, /* int: enable/disable nmi watchdog */
 	KERN_PANIC_ON_NMI=76, /* int: whether we will panic on an unrecovered */
+	KERN_AUDIT_ARGV=77, /* int: max size of argv array for audit logging */
 };
 
 
diff --git a/kernel/audit.c b/kernel/audit.c
index 4e9d208..9b08f55 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -170,6 +170,22 @@ void audit_panic(const char *message)
 	}
 }
 
+void audit_kill(const char *message)
+{
+	switch (audit_failure)
+	{
+	case AUDIT_FAIL_SILENT:
+		break;
+	case AUDIT_FAIL_PRINTK:
+		printk(KERN_ERR "audit: %s\n", message);
+		break;
+	case AUDIT_FAIL_PANIC:
+		printk(KERN_ERR "audit: %s\n", message);
+		send_sig(SIGKILL, current, 0);
+		break;
+	}
+}
+
 static inline int audit_rate_check(void)
 {
 	static unsigned long	last_check = 0;
diff --git a/kernel/audit.h b/kernel/audit.h
index a337023..9cad5ce 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -116,6 +116,7 @@ extern void		    audit_send_reply(int pid, int seq, int type,
 					     void *payload, int size);
 extern void		    audit_log_lost(const char *message);
 extern void		    audit_panic(const char *message);
+extern void		    audit_kill(const char *message);
 
 struct audit_netlink_list {
 	int pid;
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 628c7ac..402252e 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -155,7 +155,7 @@ struct audit_aux_data_execve {
 	struct audit_aux_data	d;
 	int argc;
 	int envc;
-	char mem[0];
+	struct mm_struct *mm;
 };
 
 struct audit_aux_data_socketcall {
@@ -795,6 +795,48 @@ static void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk
 	audit_log_task_context(ab);
 }
 
+static void audit_log_execve_info(struct audit_buffer *ab,
+		struct audit_aux_data_execve *axi)
+{
+	int i;
+	long len;
+	const char __user *p = (const char __user *)axi->mm->arg_start;
+
+	if (axi->mm != current->mm)
+		return; /* execve failed, no additional info */
+
+	for (i = 0; i < axi->argc; i++, p += len) {
+		long ret;
+		char *tmp;
+
+		len = strnlen_user(p, MAX_ARG_STRLEN);
+		/*
+		 * We just created this mm, if we can't find the strings
+		 * we just copied in something is _very_ wrong.
+		 */
+		BUG_ON(!len);
+
+		tmp = kmalloc(len, GFP_KERNEL);
+		if (!tmp) {
+			audit_kill("out of memory for argv string,"
+					" terminating process\n");
+			break;
+		}
+
+		ret = copy_from_user(tmp, p, len);
+		/*
+		 * There is no reason for this copy to be short.
+		 */
+		BUG_ON(ret);
+
+		audit_log_format(ab, "a%d=", i);
+		audit_log_untrustedstring(ab, tmp);
+		audit_log_format(ab, "\n");
+
+		kfree(tmp);
+	}
+}
+
 static void audit_log_exit(struct audit_context *context, struct task_struct *tsk)
 {
 	int i, call_panic = 0;
@@ -935,13 +977,7 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
 
 		case AUDIT_EXECVE: {
 			struct audit_aux_data_execve *axi = (void *)aux;
-			int i;
-			const char *p;
-			for (i = 0, p = axi->mem; i < axi->argc; i++) {
-				audit_log_format(ab, "a%d=", i);
-				p = audit_log_untrustedstring(ab, p);
-				audit_log_format(ab, "\n");
-			}
+			audit_log_execve_info(ab, axi);
 			break; }
 
 		case AUDIT_SOCKETCALL: {
@@ -1761,32 +1797,31 @@ int __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, mode_t mode
 	return 0;
 }
 
+int audit_argv_kb = 32;
+
 int audit_bprm(struct linux_binprm *bprm)
 {
 	struct audit_aux_data_execve *ax;
 	struct audit_context *context = current->audit_context;
-	unsigned long p, next;
-	void *to;
 
 	if (likely(!audit_enabled || !context || context->dummy))
 		return 0;
 
-	ax = kmalloc(sizeof(*ax) + PAGE_SIZE * MAX_ARG_PAGES - bprm->p,
-				GFP_KERNEL);
+	/*
+	 * Even though the stack code doesn't limit the arg+env size any more,
+	 * the audit code requires that _all_ arguments be logged in a single
+	 * netlink skb. Hence cap it :-(
+	 */
+	if (bprm->argv_len > (audit_argv_kb << 10))
+		return -E2BIG;
+
+	ax = kmalloc(sizeof(*ax), GFP_KERNEL);
 	if (!ax)
 		return -ENOMEM;
 
 	ax->argc = bprm->argc;
 	ax->envc = bprm->envc;
-	for (p = bprm->p, to = ax->mem; p < MAX_ARG_PAGES*PAGE_SIZE; p = next) {
-		struct page *page = bprm->page[p / PAGE_SIZE];
-		void *kaddr = kmap(page);
-		next = (p + PAGE_SIZE) & ~(PAGE_SIZE - 1);
-		memcpy(to, kaddr + (p & (PAGE_SIZE - 1)), next - p);
-		to += next - p;
-		kunmap(page);
-	}
-
+	ax->mm = bprm->mm;
 	ax->d.type = AUDIT_EXECVE;
 	ax->d.next = context->aux;
 	context->aux = (void *)ax;
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index c904748..5dfd4d7 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -76,6 +76,7 @@ extern int pid_max_min, pid_max_max;
 extern int sysctl_drop_caches;
 extern int percpu_pagelist_fraction;
 extern int compat_log;
+extern int audit_argv_kb;
 
 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
 static int maxolduid = 65535;
@@ -603,6 +604,16 @@ static ctl_table kern_table[] = {
 		.proc_handler	= &proc_dointvec,
 	},
 #endif
+#ifdef CONFIG_AUDITSYSCALL
+	{
+		.ctl_name	= KERN_AUDIT_ARGV,
+		.procname	= "audit_argv_kb",
+		.data		= &audit_argv_kb,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+#endif
 
 	{ .ctl_name = 0 }
 };
diff --git a/mm/mmap.c b/mm/mmap.c
index 88da687..8c6ceb5 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1569,33 +1569,13 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
 }
 #endif /* CONFIG_STACK_GROWSUP || CONFIG_IA64 */
 
-#ifdef CONFIG_STACK_GROWSUP
-int expand_stack(struct vm_area_struct *vma, unsigned long address)
-{
-	return expand_upwards(vma, address);
-}
-
-struct vm_area_struct *
-find_extend_vma(struct mm_struct *mm, unsigned long addr)
-{
-	struct vm_area_struct *vma, *prev;
-
-	addr &= PAGE_MASK;
-	vma = find_vma_prev(mm, addr, &prev);
-	if (vma && (vma->vm_start <= addr))
-		return vma;
-	if (!prev || expand_stack(prev, addr))
-		return NULL;
-	if (prev->vm_flags & VM_LOCKED) {
-		make_pages_present(addr, prev->vm_end);
-	}
-	return prev;
-}
-#else
 /*
  * vma is the first one with address < vma->vm_start.  Have to extend vma.
  */
-int expand_stack(struct vm_area_struct *vma, unsigned long address)
+#ifndef CONFIG_STACK_GROWSUP
+static inline
+#endif
+int expand_downwards(struct vm_area_struct *vma, unsigned long address)
 {
 	int error;
 
@@ -1632,6 +1612,34 @@ int expand_stack(struct vm_area_struct *vma, unsigned long address)
 	return error;
 }
 
+#ifdef CONFIG_STACK_GROWSUP
+int expand_stack(struct vm_area_struct *vma, unsigned long address)
+{
+	return expand_upwards(vma, address);
+}
+
+struct vm_area_struct *
+find_extend_vma(struct mm_struct *mm, unsigned long addr)
+{
+	struct vm_area_struct *vma, *prev;
+
+	addr &= PAGE_MASK;
+	vma = find_vma_prev(mm, addr, &prev);
+	if (vma && (vma->vm_start <= addr))
+		return vma;
+	if (!prev || expand_stack(prev, addr))
+		return NULL;
+	if (prev->vm_flags & VM_LOCKED) {
+		make_pages_present(addr, prev->vm_end);
+	}
+	return prev;
+}
+#else
+int expand_stack(struct vm_area_struct *vma, unsigned long address)
+{
+	return expand_downwards(vma, address);
+}
+
 struct vm_area_struct *
 find_extend_vma(struct mm_struct * mm, unsigned long addr)
 {
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 3b8f3c0..e8346c3 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -128,7 +128,7 @@ static void change_protection(struct vm_area_struct *vma,
 	flush_tlb_range(vma, start, end);
 }
 
-static int
+int
 mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
 	unsigned long start, unsigned long end, unsigned long newflags)
 {
diff --git a/mm/mremap.c b/mm/mremap.c
index 5d4bd4f..858a36b 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -118,9 +118,63 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
 		spin_unlock(&mapping->i_mmap_lock);
 }
 
+static void move_ptes_up(struct vm_area_struct *vma, pmd_t *old_pmd,
+		unsigned long old_addr, unsigned long old_end,
+		struct vm_area_struct *new_vma, pmd_t *new_pmd,
+		unsigned long new_addr)
+{
+	struct address_space *mapping = NULL;
+	struct mm_struct *mm = vma->vm_mm;
+	pte_t *old_pte, *new_pte, pte;
+	spinlock_t *old_ptl, *new_ptl;
+	unsigned long new_end = new_addr + (old_end - old_addr);
+
+	if (vma->vm_file) {
+		/*
+		 * Subtle point from Rajesh Venkatasubramanian: before
+		 * moving file-based ptes, we must lock vmtruncate out,
+		 * since it might clean the dst vma before the src vma,
+		 * and we propagate stale pages into the dst afterward.
+		 */
+		mapping = vma->vm_file->f_mapping;
+		spin_lock(&mapping->i_mmap_lock);
+		if (new_vma->vm_truncate_count &&
+		    new_vma->vm_truncate_count != vma->vm_truncate_count)
+			new_vma->vm_truncate_count = 0;
+	}
+
+	/*
+	 * We don't have to worry about the ordering of src and dst
+	 * pte locks because exclusive mmap_sem prevents deadlock.
+	 */
+	old_pte = pte_offset_map_lock(mm, old_pmd, old_end-1, &old_ptl);
+ 	new_pte = pte_offset_map_nested(new_pmd, new_end-1);
+	new_ptl = pte_lockptr(mm, new_pmd);
+	if (new_ptl != old_ptl)
+		spin_lock_nested(new_ptl, SINGLE_DEPTH_NESTING);
+	arch_enter_lazy_mmu_mode();
+
+	for (; old_end > old_addr; old_pte--, old_end -= PAGE_SIZE,
+				   new_pte--, new_end -= PAGE_SIZE) {
+		if (pte_none(*old_pte))
+			continue;
+		pte = ptep_clear_flush(vma, old_end-1, old_pte);
+		pte = move_pte(pte, new_vma->vm_page_prot, old_end-1, new_end-1);
+		set_pte_at(mm, new_end-1, new_pte, pte);
+	}
+
+	arch_leave_lazy_mmu_mode();
+	if (new_ptl != old_ptl)
+		spin_unlock(new_ptl);
+	pte_unmap_nested(new_pte - 1);
+	pte_unmap_unlock(old_pte - 1, old_ptl);
+	if (mapping)
+		spin_unlock(&mapping->i_mmap_lock);
+}
+
 #define LATENCY_LIMIT	(64 * PAGE_SIZE)
 
-static unsigned long move_page_tables(struct vm_area_struct *vma,
+unsigned long move_page_tables(struct vm_area_struct *vma,
 		unsigned long old_addr, struct vm_area_struct *new_vma,
 		unsigned long new_addr, unsigned long len)
 {
@@ -132,21 +186,25 @@ static unsigned long move_page_tables(struct vm_area_struct *vma,
 
 	for (; old_addr < old_end; old_addr += extent, new_addr += extent) {
 		cond_resched();
+
 		next = (old_addr + PMD_SIZE) & PMD_MASK;
 		if (next - 1 > old_end)
 			next = old_end;
 		extent = next - old_addr;
+
 		old_pmd = get_old_pmd(vma->vm_mm, old_addr);
 		if (!old_pmd)
 			continue;
 		new_pmd = alloc_new_pmd(vma->vm_mm, new_addr);
 		if (!new_pmd)
 			break;
+
 		next = (new_addr + PMD_SIZE) & PMD_MASK;
 		if (extent > next - new_addr)
 			extent = next - new_addr;
 		if (extent > LATENCY_LIMIT)
 			extent = LATENCY_LIMIT;
+
 		move_ptes(vma, old_pmd, old_addr, old_addr + extent,
 				new_vma, new_pmd, new_addr);
 	}
@@ -154,6 +212,51 @@ static unsigned long move_page_tables(struct vm_area_struct *vma,
 	return len + old_addr - old_end;	/* how much done */
 }
 
+unsigned long move_page_tables_up(struct vm_area_struct *vma,
+		unsigned long old_addr, struct vm_area_struct *new_vma,
+		unsigned long new_addr, unsigned long len)
+{
+	unsigned long extent, prev, old_end, new_end;
+	pmd_t *old_pmd, *new_pmd;
+
+	old_end = old_addr + len;
+	new_end = new_addr + len;
+	flush_cache_range(vma, old_addr, old_end);
+
+	for (; old_end > old_addr; old_end -= extent, new_end -= extent) {
+		cond_resched();
+
+		/*
+		 * calculate how far till prev PMD boundary for old
+		 */
+		prev = (old_end - 1) & PMD_MASK;
+		if (prev < old_addr)
+			prev = old_addr;
+		extent = old_end - prev;
+
+		old_pmd = get_old_pmd(vma->vm_mm, old_end-1);
+		if (!old_pmd)
+			continue;
+		new_pmd = alloc_new_pmd(vma->vm_mm, new_end-1);
+		if (!new_pmd)
+			break;
+
+		/*
+		 * calculate and clip to prev PMD boundary for new
+		 */
+		prev = (new_end - 1) & PMD_MASK;
+		if (extent > new_end - prev)
+			extent = new_end - prev;
+		if (extent > LATENCY_LIMIT)
+			extent = LATENCY_LIMIT;
+
+		move_ptes_up(vma, old_pmd, old_end - extent, old_end,
+				new_vma, new_pmd, new_end - extent);
+	}
+
+	return old_addr + len - old_end;
+}
+
 static unsigned long move_vma(struct vm_area_struct *vma,
 		unsigned long old_addr, unsigned long old_len,
 		unsigned long new_len, unsigned long new_addr)

^ permalink raw reply	[flat|nested] 11+ messages in thread
end of thread, other threads:[~2007-05-25 18:48 UTC | newest]

Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2007-05-06  8:51 [patch] removes MAX_ARG_PAGES Ollie Wild
2007-05-07 17:46 ` Luck, Tony
2007-05-07 19:01   ` William Lee Irwin III
2007-05-22 12:24   ` Peter Zijlstra
2007-05-22 23:49     ` Luck, Tony
2007-05-24 15:20       ` Peter Zijlstra
2007-05-25 18:48         ` Luck, Tony
2007-05-09 20:48 ` Andrew Morton
2007-05-10  1:04   ` Rob Landley
2007-05-10  4:06     ` Ollie Wild
2007-05-10  9:19       ` Rob Landley

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox