[PATCH] rmap 26 __setup_arg_pages

From: Hugh Dickins (hugh_at_veritas.com)
Date: 05/08/04

  • Next message: Hugh Dickins: "[PATCH] rmap 27 memset 0 vma" 
    Date:	Sat, 8 May 2004 22:58:31 +0100 (BST)
To: Andrew Morton <akpm@osdl.org>

    anon_vma will need to pass vma to "put_dirty_page"; but instead of just
    adding that arg to its callers, try to tidy this area up a little with
    __setup_arg_pages(bprm, stack_top, vm_stack_flags), cutting duplicated
    code out of the 64-bit support for 32-bit execs. Still fairly horrid
    (they tend to #include fs/binfmt_elf.c after #defining setup_arg_pages
    to local variant), I'd break their builds if we went further.

    Rename put_dirty_page to install_arg_page, now static to fs/exec.c.
    While there, moved its flush_dcache_page up before page_table_lock -
    doesn't in fact matter at all, just saves one worry when researching
    flush_dcache_page locking constraints.

     arch/ia64/ia32/binfmt_elf32.c | 59 +++----------------------------
     arch/ia64/mm/init.c | 2 -
     arch/s390/kernel/compat_exec.c | 78 +----------------------------------------
     arch/x86_64/ia32/ia32_binfmt.c | 65 ++++------------------------------
     fs/exec.c | 52 +++++++++++++++------------
     include/linux/binfmts.h | 2 +
     include/linux/mm.h | 2 -
     7 files changed, 49 insertions(+), 211 deletions(-)

    --- rmap25/arch/ia64/ia32/binfmt_elf32.c 2004-05-05 13:29:08.000000000 +0100
    +++ rmap26/arch/ia64/ia32/binfmt_elf32.c 2004-05-08 20:54:54.347237808 +0100
    @@ -152,61 +152,14 @@ ia64_elf32_init (struct pt_regs *regs)
     int
     ia32_setup_arg_pages (struct linux_binprm *bprm, int executable_stack)
     {
    - unsigned long stack_base;
    - struct vm_area_struct *mpnt;
    - struct mm_struct *mm = current->mm;
    - int i;
    + unsigned long vm_stack_flags = VM_STACK_FLAGS;
     
    - stack_base = IA32_STACK_TOP - MAX_ARG_PAGES*PAGE_SIZE;
    - mm->arg_start = bprm->p + stack_base;
    + if (executable_stack == EXSTACK_ENABLE_X)
    + vm_stack_flags |= VM_EXEC;
    + else if (executable_stack == EXSTACK_DISABLE_X)
    + vm_stack_flags &= ~VM_EXEC;
     
    - bprm->p += stack_base;
    - if (bprm->loader)
    - bprm->loader += stack_base;
    - bprm->exec += stack_base;
    -
    - mpnt = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
    - if (!mpnt)
    - return -ENOMEM;
    -
    - if (security_vm_enough_memory((IA32_STACK_TOP - (PAGE_MASK & (unsigned long) bprm->p))>>PAGE_SHIFT)) {
    - kmem_cache_free(vm_area_cachep, mpnt);
    - return -ENOMEM;
    - }
    -
    - down_write(&current->mm->mmap_sem);
    - {
    - mpnt->vm_mm = current->mm;
    - mpnt->vm_start = PAGE_MASK & (unsigned long) bprm->p;
    - mpnt->vm_end = IA32_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;
    - mpnt->vm_ops = NULL;
    - mpnt->vm_pgoff = 0;
    - mpnt->vm_file = NULL;
    - mpnt->vm_private_data = 0;
    - mpol_set_vma_default(mpnt);
    - insert_vm_struct(current->mm, mpnt);
    - current->mm->total_vm = (mpnt->vm_end - mpnt->vm_start) >> PAGE_SHIFT;
    - }
    -
    - for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
    - struct page *page = bprm->page[i];
    - if (page) {
    - bprm->page[i] = NULL;
    - put_dirty_page(current, page, stack_base, mpnt->vm_page_prot);
    - }
    - stack_base += PAGE_SIZE;
    - }
    - up_write(&current->mm->mmap_sem);
    -
    - return 0;
    + return __setup_arg_pages(bprm, IA32_STACK_TOP, vm_stack_flags);
     }
     
     static void
    --- rmap25/arch/ia64/mm/init.c 2004-05-05 13:29:12.000000000 +0100
    +++ rmap26/arch/ia64/mm/init.c 2004-05-08 20:54:54.349237504 +0100
    @@ -222,7 +222,7 @@ free_initrd_mem (unsigned long start, un
     }
     
     /*
    - * This is like put_dirty_page() but installs a clean page in the kernel's page table.
    + * This installs a clean page in the kernel's page table.
      */
     struct page *
     put_kernel_page (struct page *page, unsigned long address, pgprot_t pgprot)
    --- rmap25/arch/s390/kernel/compat_exec.c 2004-05-05 13:29:08.000000000 +0100
    +++ rmap26/arch/s390/kernel/compat_exec.c 2004-05-08 20:54:54.350237352 +0100
    @@ -8,87 +8,13 @@
      *
      */
     
    -#include <linux/config.h>
    -#include <linux/slab.h>
    -#include <linux/file.h>
    -#include <linux/mman.h>
    -#include <linux/a.out.h>
    -#include <linux/stat.h>
    -#include <linux/fcntl.h>
    -#include <linux/smp_lock.h>
    -#include <linux/init.h>
    -#include <linux/pagemap.h>
     #include <linux/mm.h>
    -#include <linux/highmem.h>
    -#include <linux/spinlock.h>
     #include <linux/binfmts.h>
     #include <linux/module.h>
    -#include <linux/security.h>
    -
    -#include <asm/uaccess.h>
    -#include <asm/pgalloc.h>
    -#include <asm/mmu_context.h>
    -
    -#ifdef CONFIG_KMOD
    -#include <linux/kmod.h>
    -#endif
    -
    -
    -#undef STACK_TOP
    -#define STACK_TOP TASK31_SIZE
     
     int setup_arg_pages32(struct linux_binprm *bprm, int executable_stack)
     {
    - unsigned long stack_base;
    - struct vm_area_struct *mpnt;
    - struct mm_struct *mm = current->mm;
    - int i;
    -
    - 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_alloc(vm_area_cachep, SLAB_KERNEL);
    - if (!mpnt)
    - return -ENOMEM;
    -
    - if (security_vm_enough_memory((STACK_TOP - (PAGE_MASK & (unsigned long) bprm->p))>>PAGE_SHIFT)) {
    - kmem_cache_free(vm_area_cachep, 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;
    - /* executable stack setting would be applied here */
    - mpnt->vm_page_prot = PAGE_COPY;
    - mpnt->vm_flags = VM_STACK_FLAGS;
    - mpnt->vm_ops = NULL;
    - mpnt->vm_pgoff = 0;
    - mpnt->vm_file = NULL;
    - mpol_set_vma_default(mpnt);
    - mpnt->vm_private_data = (void *) 0;
    - insert_vm_struct(mm, mpnt);
    - mm->total_vm = (mpnt->vm_end - mpnt->vm_start) >> PAGE_SHIFT;
    - }
    -
    - for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
    - struct page *page = bprm->page[i];
    - if (page) {
    - bprm->page[i] = NULL;
    - put_dirty_page(current,page,stack_base,PAGE_COPY);
    - }
    - stack_base += PAGE_SIZE;
    - }
    - up_write(&mm->mmap_sem);
    -
    - return 0;
    + /* executable_stack argument is currently ignored */
    + return __setup_arg_pages(bprm, TASK31_SIZE, VM_STACK_FLAGS);
     }
    -
     EXPORT_SYMBOL(setup_arg_pages32);
    --- rmap25/arch/x86_64/ia32/ia32_binfmt.c 2004-05-05 13:29:08.000000000 +0100
    +++ rmap26/arch/x86_64/ia32/ia32_binfmt.c 2004-05-08 20:54:54.351237200 +0100
    @@ -325,63 +325,16 @@ static void elf32_init(struct pt_regs *r
             me->thread.es = __USER_DS;
     }
     
    -int setup_arg_pages(struct linux_binprm *bprm, int executable_stack)
    +int ia32_setup_arg_pages(struct linux_binprm *bprm, int executable_stack)
     {
    - unsigned long stack_base;
    - struct vm_area_struct *mpnt;
    - struct mm_struct *mm = current->mm;
    - int i;
    -
    - stack_base = IA32_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_alloc(vm_area_cachep, SLAB_KERNEL);
    - if (!mpnt)
    - return -ENOMEM;
    -
    - if (security_vm_enough_memory((IA32_STACK_TOP - (PAGE_MASK & (unsigned long) bprm->p))>>PAGE_SHIFT)) {
    - kmem_cache_free(vm_area_cachep, mpnt);
    - return -ENOMEM;
    - }
    -
    - down_write(&mm->mmap_sem);
    - {
    - mpnt->vm_mm = mm;
    - mpnt->vm_start = PAGE_MASK & (unsigned long) bprm->p;
    - mpnt->vm_end = IA32_STACK_TOP;
    - if (executable_stack == EXSTACK_ENABLE_X)
    - mpnt->vm_flags = vm_stack_flags32 | VM_EXEC;
    - else if (executable_stack == EXSTACK_DISABLE_X)
    - mpnt->vm_flags = vm_stack_flags32 & ~VM_EXEC;
    - else
    - mpnt->vm_flags = vm_stack_flags32;
    - mpnt->vm_page_prot = (mpnt->vm_flags & VM_EXEC) ?
    - PAGE_COPY_EXEC : PAGE_COPY;
    - mpnt->vm_ops = NULL;
    - mpnt->vm_pgoff = 0;
    - mpnt->vm_file = NULL;
    - mpol_set_vma_default(mpnt);
    - mpnt->vm_private_data = (void *) 0;
    - insert_vm_struct(mm, mpnt);
    - mm->total_vm = (mpnt->vm_end - mpnt->vm_start) >> PAGE_SHIFT;
    - }
    -
    - for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
    - struct page *page = bprm->page[i];
    - if (page) {
    - bprm->page[i] = NULL;
    - put_dirty_page(current,page,stack_base,mpnt->vm_page_prot);
    - }
    - stack_base += PAGE_SIZE;
    - }
    - up_write(&mm->mmap_sem);
    -
    - return 0;
    + unsigned long vm_stack_flags = vm_stack_flags32;
    +
    + if (executable_stack == EXSTACK_ENABLE_X)
    + vm_stack_flags |= VM_EXEC;
    + else if (executable_stack == EXSTACK_DISABLE_X)
    + vm_stack_flags &= ~VM_EXEC;
    +
    + return __setup_arg_pages(bprm, IA32_STACK_TOP, vm_stack_flags);
     }
     
     static unsigned long
    --- rmap25/fs/exec.c 2004-05-05 13:29:10.000000000 +0100
    +++ rmap26/fs/exec.c 2004-05-08 20:54:54.354236744 +0100
    @@ -293,17 +293,19 @@ EXPORT_SYMBOL(copy_strings_kernel);
      * This routine is used to map in a page into an address space: needed by
      * execve() for the initial stack and environment pages.
      *
    - * tsk->mm->mmap_sem is held for writing.
    + * vma->vm_mm->mmap_sem is held for writing.
      */
    -void put_dirty_page(struct task_struct *tsk, struct page *page,
    - unsigned long address, pgprot_t prot)
    +static void install_arg_page(struct vm_area_struct *vma,
    + struct page *page, unsigned long address)
     {
    - struct mm_struct *mm = tsk->mm;
    + struct mm_struct *mm = vma->vm_mm;
             pgd_t * pgd;
             pmd_t * pmd;
             pte_t * pte;
     
    + flush_dcache_page(page);
             pgd = pgd_offset(mm, address);
    +
             spin_lock(&mm->page_table_lock);
             pmd = pmd_alloc(mm, pgd, address);
             if (!pmd)
    @@ -317,8 +319,8 @@ void put_dirty_page(struct task_struct *
             }
             mm->rss++;
             lru_cache_add_active(page);
    - flush_dcache_page(page);
    - set_pte(pte, pte_mkdirty(pte_mkwrite(mk_pte(page, prot))));
    + set_pte(pte, pte_mkdirty(pte_mkwrite(mk_pte(
    + page, vma->vm_page_prot))));
             page_add_anon_rmap(page, mm, address);
             pte_unmap(pte);
             spin_unlock(&mm->page_table_lock);
    @@ -328,10 +330,11 @@ void put_dirty_page(struct task_struct *
     out:
             spin_unlock(&mm->page_table_lock);
             __free_page(page);
    - force_sig(SIGKILL, tsk);
    + force_sig(SIGKILL, current);
     }
     
    -int setup_arg_pages(struct linux_binprm *bprm, int executable_stack)
    +int __setup_arg_pages(struct linux_binprm *bprm,
    + unsigned long stack_top, unsigned long vm_stack_flags)
     {
             unsigned long stack_base;
             struct vm_area_struct *mpnt;
    @@ -375,7 +378,7 @@ int setup_arg_pages(struct linux_binprm
             stack_base = current->rlim[RLIMIT_STACK].rlim_max;
             if (stack_base > (1 << 30))
                     stack_base = 1 << 30;
    - stack_base = PAGE_ALIGN(STACK_TOP - stack_base);
    + stack_base = PAGE_ALIGN(stack_top - stack_base);
     
             mm->arg_start = stack_base;
             arg_size = i << PAGE_SHIFT;
    @@ -384,9 +387,9 @@ int setup_arg_pages(struct linux_binprm
             while (i < MAX_ARG_PAGES)
                     bprm->page[i++] = NULL;
     #else
    - stack_base = STACK_TOP - MAX_ARG_PAGES * PAGE_SIZE;
    + stack_base = stack_top - MAX_ARG_PAGES * PAGE_SIZE;
             mm->arg_start = bprm->p + stack_base;
    - arg_size = STACK_TOP - (PAGE_MASK & (unsigned long) mm->arg_start);
    + arg_size = stack_top - (PAGE_MASK & (unsigned long) mm->arg_start);
     #endif
     
             bprm->p += stack_base;
    @@ -412,17 +415,9 @@ int setup_arg_pages(struct linux_binprm
                             (PAGE_SIZE - 1 + (unsigned long) bprm->p);
     #else
                     mpnt->vm_start = PAGE_MASK & (unsigned long) bprm->p;
    - mpnt->vm_end = STACK_TOP;
    + mpnt->vm_end = stack_top;
     #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 = vm_stack_flags;
                     mpnt->vm_page_prot = protection_map[mpnt->vm_flags & 0x7];
                     mpnt->vm_ops = NULL;
                     mpnt->vm_pgoff = 0;
    @@ -437,8 +432,7 @@ int setup_arg_pages(struct linux_binprm
                     struct page *page = bprm->page[i];
                     if (page) {
                             bprm->page[i] = NULL;
    - put_dirty_page(current, page, stack_base,
    - mpnt->vm_page_prot);
    + install_arg_page(mpnt, page, stack_base);
                     }
                     stack_base += PAGE_SIZE;
             }
    @@ -446,7 +440,19 @@ int setup_arg_pages(struct linux_binprm
             
             return 0;
     }
    +EXPORT_SYMBOL(__setup_arg_pages);
     
    +int setup_arg_pages(struct linux_binprm *bprm, int executable_stack)
    +{
    + unsigned long vm_stack_flags = VM_STACK_FLAGS;
    +
    + if (executable_stack == EXSTACK_ENABLE_X)
    + vm_stack_flags |= VM_EXEC;
    + else if (executable_stack == EXSTACK_DISABLE_X)
    + vm_stack_flags &= ~VM_EXEC;
    +
    + return __setup_arg_pages(bprm, STACK_TOP, vm_stack_flags);
    +}
     EXPORT_SYMBOL(setup_arg_pages);
     
     #define free_arg_pages(bprm) do { } while (0)
    --- rmap25/include/linux/binfmts.h 2004-05-05 13:29:09.000000000 +0100
    +++ rmap26/include/linux/binfmts.h 2004-05-08 20:54:54.355236592 +0100
    @@ -69,6 +69,8 @@ extern int flush_old_exec(struct linux_b
     #define EXSTACK_ENABLE_X 2 /* Enable executable stacks */
     
     extern int setup_arg_pages(struct linux_binprm * bprm, int executable_stack);
    +extern int __setup_arg_pages(struct linux_binprm *bprm,
    + unsigned long stack_top, unsigned long vm_flags);
     extern int copy_strings(int argc,char __user * __user * argv,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);
    --- rmap25/include/linux/mm.h 2004-05-05 13:29:08.000000000 +0100
    +++ rmap26/include/linux/mm.h 2004-05-08 20:54:54.356236440 +0100
    @@ -495,8 +495,6 @@ extern int install_file_pte(struct mm_st
     extern int handle_mm_fault(struct mm_struct *mm,struct vm_area_struct *vma, unsigned long address, int write_access);
     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 put_dirty_page(struct task_struct *tsk, struct page *page,
    - unsigned long address, pgprot_t prot);
     
     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);

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