diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/binfmt_elf.c | 28 | ||||
| -rw-r--r-- | fs/binfmt_elf_fdpic.c | 8 | ||||
| -rw-r--r-- | fs/binfmt_misc.c | 4 | ||||
| -rw-r--r-- | fs/binfmt_script.c | 4 | ||||
| -rw-r--r-- | fs/compat.c | 128 | ||||
| -rw-r--r-- | fs/exec.c | 614 |
6 files changed, 478 insertions, 308 deletions
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index a27e42b..295cbaa 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -148,6 +148,7 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec, elf_addr_t *elf_info; int ei_index = 0; struct task_struct *tsk = current; + struct vm_area_struct *vma; /* * If this architecture has a platform capability string, copy it @@ -234,6 +235,15 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec, 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; @@ -254,8 +264,8 @@ 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 +276,8 @@ 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; } @@ -826,10 +836,6 @@ 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; @@ -1051,9 +1057,13 @@ 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(SIGKILL, 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 9d62fbad..4739506 100644 --- a/fs/binfmt_elf_fdpic.c +++ b/fs/binfmt_elf_fdpic.c @@ -621,8 +621,8 @@ 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; } @@ -633,8 +633,8 @@ 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 330fd3f..42e94b3 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 304c885..4d0e0f6 100644 --- a/fs/binfmt_script.c +++ b/fs/binfmt_script.c @@ -67,7 +67,9 @@ 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 4db6216..15078ce 100644 --- a/fs/compat.c +++ b/fs/compat.c @@ -1257,6 +1257,7 @@ 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) { @@ -1265,92 +1266,84 @@ 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 (len > MAX_ARG_STRLEN) { 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_stack_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. @@ -1363,7 +1356,6 @@ 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); @@ -1377,24 +1369,19 @@ 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; @@ -1421,8 +1408,6 @@ int compat_do_execve(char * filename, retval = search_binary_handler(bprm, regs); if (retval >= 0) { - free_arg_pages(bprm); - /* execve success */ security_bprm_free(bprm); acct_update_integrals(current); @@ -1431,19 +1416,12 @@ 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) { @@ -54,6 +54,7 @@ #include <asm/uaccess.h> #include <asm/mmu_context.h> +#include <asm/tlb.h> #ifdef CONFIG_KMOD #include <linux/kmod.h> @@ -178,6 +179,207 @@ 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_stack_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; + + if (write) { + struct rlimit *rlim = current->signal->rlim; + unsigned long size = bprm->vma->vm_end - bprm->vma->vm_start; + + /* + * Limit to 1/4-th the stack size for the argv+env strings. + * This ensures that: + * - the remaining binfmt code will not run out of stack space, + * - the program will have a reasonable amount of stack left + * to work from. + */ + if (size > rlim[RLIMIT_STACK].rlim_cur / 4) { + put_page(page); + 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) +{ +} + +static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos, + struct page *page) +{ + flush_cache_page(bprm->vma, pos, page_to_pfn(page)); +} + +static int __bprm_mm_init(struct linux_binprm *bprm) +{ + int err = -ENOMEM; + struct vm_area_struct *vma = NULL; + struct mm_struct *mm = bprm->mm; + + bprm->vma = vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL); + if (!vma) + goto err; + + down_write(&mm->mmap_sem); + vma->vm_mm = mm; + + /* + * Place the stack at the largest stack address the architecture + * supports. 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 = STACK_TOP_MAX; + vma->vm_start = vma->vm_end - PAGE_SIZE; + + vma->vm_flags = VM_STACK_FLAGS; + vma->vm_page_prot = protection_map[vma->vm_flags & 0x7]; + err = insert_vm_struct(mm, vma); + if (err) { + 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 *); + + return 0; + +err: + if (vma) { + bprm->vma = NULL; + kmem_cache_free(vm_area_cachep, vma); + } + + return err; +} + +static bool valid_arg_len(struct linux_binprm *bprm, long len) +{ + return len <= MAX_ARG_STRLEN; +} + +#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); +} + +static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos, + struct page *page) +{ +} + +static int __bprm_mm_init(struct linux_binprm *bprm) +{ + bprm->p = PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *); + return 0; +} + +static bool valid_arg_len(struct linux_binprm *bprm, long len) +{ + return len <= bprm->p; +} + +#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; + + bprm->mm = mm = mm_alloc(); + err = -ENOMEM; + if (!mm) + goto err; + + err = init_new_context(current, mm); + if (err) + goto err; + + err = __bprm_mm_init(bprm); + if (err) + goto err; + + return 0; + +err: + if (mm) { + bprm->mm = NULL; + mmdrop(mm); + } + + return err; +} + /* * count() counts the number of strings in array ARGV. */ @@ -203,15 +405,16 @@ 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) { @@ -220,69 +423,69 @@ 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) { + if (!valid_arg_len(bprm, 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 (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_arg_page(bprm, kpos, 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; } @@ -298,181 +501,172 @@ int copy_strings_kernel(int argc,char ** argv, struct linux_binprm *bprm) set_fs(oldfs); return r; } - 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. + * During bprm_mm_init(), we create a temporary stack at STACK_TOP_MAX. Once + * the binfmt code determines where the new stack should reside, we shift it to + * its final location. The process proceeds as follows: * - * vma->vm_mm->mmap_sem is held for writing. + * 1) Use shift to calculate the new vma endpoints. + * 2) Extend vma to cover both the old and new ranges. This ensures the + * arguments passed to subsequent functions are consistent. + * 3) Move vma's page tables to the new range. + * 4) Free up any cleared pgd range. + * 5) Shrink the vma to cover only the new range. */ -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; - if (unlikely(anon_vma_prepare(vma))) - goto out; + BUG_ON(new_start > new_end); - 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; + /* + * ensure there are no vmas between where we want to go + * and where we are + */ + if (vma != find_vma(mm, new_start)) + return -EFAULT; + + /* + * cover the whole range: [new_start, old_end) + */ + vma_adjust(vma, new_start, old_end, vma->vm_pgoff, NULL); + + /* + * move the page tables downwards, on failure we rely on + * process cleanup to remove whatever mess we made. + */ + if (length != move_page_tables(vma, old_start, + vma, new_start, length)) + return -ENOMEM; + + lru_add_drain(); + tlb = tlb_gather_mmu(mm, 0); + if (new_end > old_start) { + /* + * when the old and new regions overlap clear from new_end. + */ + free_pgd_range(&tlb, new_end, old_end, new_end, + vma->vm_next ? vma->vm_next->vm_start : 0); + } else { + /* + * otherwise, clean from old_start; this is done to not touch + * the address space in [new_end, old_start) some architectures + * have constraints on va-space that make this illegal (IA64) - + * for the others its just a little faster. + */ + free_pgd_range(&tlb, old_start, old_end, new_end, + vma->vm_next ? vma->vm_next->vm_start : 0); } - 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); + tlb_finish_mmu(tlb, new_end, old_end); + + /* + * shrink the vma to just the new range. + */ + vma_adjust(vma, new_start, new_end, vma->vm_pgoff, NULL); + + 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_shift; struct mm_struct *mm = current->mm; - int i, ret; - long arg_size; + struct vm_area_struct *vma = bprm->vma; + struct vm_area_struct *prev = NULL; + unsigned long vm_flags; + unsigned long stack_base; #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; + /* Make sure we didn't let the argument array grow too large. */ + if (vma->vm_end - vma->vm_start > stack_base) + return -ENOMEM; - mm->arg_start = stack_base; - arg_size = i << PAGE_SHIFT; + stack_base = PAGE_ALIGN(stack_top - stack_base); - /* zero pages that were copied above */ - while (i < MAX_ARG_PAGES) - bprm->page[i++] = NULL; + stack_shift = vma->vm_start - stack_base; + 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); - stack_base = PAGE_ALIGN(stack_base); - bprm->p += stack_base; + stack_top = arch_align_stack(stack_top); + stack_top = PAGE_ALIGN(stack_top); + stack_shift = vma->vm_end - stack_top; + + 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 - /* 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; - 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 = 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)) + vm_flags |= VM_EXEC; + else if (executable_stack == EXSTACK_DISABLE_X) + vm_flags &= ~VM_EXEC; + vm_flags |= mm->def_flags; + + ret = mprotect_fixup(vma, &prev, vma->vm_start, vma->vm_end, + vm_flags); + if (ret) + goto out_unlock; + 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); - 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; - } +#ifdef CONFIG_STACK_GROWSUP + stack_base = vma->vm_end + EXTRA_STACK_VM_PAGES * PAGE_SIZE; +#else + stack_base = vma->vm_start - EXTRA_STACK_VM_PAGES * PAGE_SIZE; +#endif + ret = expand_stack(vma, stack_base); + if (ret) + ret = -EFAULT; + +out_unlock: up_write(&mm->mmap_sem); - return 0; } - 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) @@ -1000,43 +1194,42 @@ EXPORT_SYMBOL(compute_creds); * points to; chop off the first by relocating brpm->p to right after * the first '\0' encountered. */ -void remove_arg_zero(struct linux_binprm *bprm) +int remove_arg_zero(struct linux_binprm *bprm) { - if (bprm->argc) { - char ch; + int ret = 0; + unsigned long offset; + char *kaddr; + struct page *page; - do { - unsigned long offset; - unsigned long index; - char *kaddr; - struct page *page; - - offset = bprm->p & ~PAGE_MASK; - index = bprm->p >> PAGE_SHIFT; + if (!bprm->argc) + return 0; - page = bprm->page[index]; - 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); - /* run through page until we reach end or find NUL */ - do { - ch = *(kaddr + offset); + for (; offset < PAGE_SIZE && kaddr[offset]; + offset++, bprm->p++) + ; - /* discard that character... */ - bprm->p++; - offset++; - } while (offset < PAGE_SIZE && ch != '\0'); + kunmap_atomic(kaddr, KM_USER0); + put_arg_page(page); - kunmap_atomic(kaddr, KM_USER0); + if (offset == PAGE_SIZE) + free_arg_page(bprm, (bprm->p >> PAGE_SHIFT) - 1); + } while (offset == PAGE_SIZE); - /* free the old page */ - if (offset == PAGE_SIZE) { - __free_page(page); - bprm->page[index] = NULL; - } - } while (ch != '\0'); + bprm->p++; + bprm->argc--; + ret = 0; - bprm->argc--; - } +out: + return ret; } EXPORT_SYMBOL(remove_arg_zero); @@ -1062,7 +1255,7 @@ 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); @@ -1156,7 +1349,6 @@ int do_execve(char * filename, struct file *file; unsigned long env_p; int retval; - int i; retval = -ENOMEM; bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); @@ -1170,25 +1362,19 @@ 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; @@ -1217,9 +1403,8 @@ int do_execve(char * filename, 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); @@ -1227,26 +1412,19 @@ 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); |
