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authorOllie Wild <aaw@google.com>2007-07-19 01:48:16 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-19 10:04:45 -0700
commitb6a2fea39318e43fee84fa7b0b90d68bed92d2ba (patch)
treec9c3619cb2730b5c10c7427b837146bce3d69156 /arch
parentbdf4c48af20a3b0f01671799ace345e3d49576da (diff)
downloadop-kernel-dev-b6a2fea39318e43fee84fa7b0b90d68bed92d2ba.zip
op-kernel-dev-b6a2fea39318e43fee84fa7b0b90d68bed92d2ba.tar.gz
mm: variable length argument support
Remove the arg+env limit of MAX_ARG_PAGES by copying the strings directly from the old mm into the new mm. We create the new mm before the binfmt code runs, and place the new stack at the very top of the address space. Once the binfmt code runs and figures out where the stack should be, we move it downwards. It is a bit peculiar in that we have one task with two mm's, one of which is inactive. [a.p.zijlstra@chello.nl: limit stack size] Signed-off-by: Ollie Wild <aaw@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: <linux-arch@vger.kernel.org> Cc: Hugh Dickins <hugh@veritas.com> [bunk@stusta.de: unexport bprm_mm_init] Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/ia64/ia32/binfmt_elf32.c67
-rw-r--r--arch/x86_64/ia32/ia32_aout.c2
-rw-r--r--arch/x86_64/ia32/ia32_binfmt.c58
3 files changed, 17 insertions, 110 deletions
diff --git a/arch/ia64/ia32/binfmt_elf32.c b/arch/ia64/ia32/binfmt_elf32.c
index 6f4d3d0..e1189ba 100644
--- a/arch/ia64/ia32/binfmt_elf32.c
+++ b/arch/ia64/ia32/binfmt_elf32.c
@@ -195,62 +195,27 @@ ia64_elf32_init (struct pt_regs *regs)
ia32_load_state(current);
}
+/*
+ * Undo the override of setup_arg_pages() without this ia32_setup_arg_pages()
+ * will suffer infinite self recursion.
+ */
+#undef setup_arg_pages
+
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, ret;
-
- 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_zalloc(vm_area_cachep, GFP_KERNEL);
- if (!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;
- if ((ret = insert_vm_struct(current->mm, mpnt))) {
- up_write(&current->mm->mmap_sem);
- kmem_cache_free(vm_area_cachep, mpnt);
- return ret;
- }
- current->mm->stack_vm = current->mm->total_vm = vma_pages(mpnt);
+ int ret;
+
+ ret = setup_arg_pages(bprm, IA32_STACK_TOP, executable_stack);
+ if (!ret) {
+ /*
+ * Can't do it in ia64_elf32_init(). Needs to be done before
+ * calls to elf32_map()
+ */
+ current->thread.ppl = ia32_init_pp_list();
}
- 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(&current->mm->mmap_sem);
-
- /* Can't do it in ia64_elf32_init(). Needs to be done before calls to
- elf32_map() */
- current->thread.ppl = ia32_init_pp_list();
-
- return 0;
+ return ret;
}
static void
diff --git a/arch/x86_64/ia32/ia32_aout.c b/arch/x86_64/ia32/ia32_aout.c
index fe83edb..0878137 100644
--- a/arch/x86_64/ia32/ia32_aout.c
+++ b/arch/x86_64/ia32/ia32_aout.c
@@ -404,7 +404,7 @@ beyond_if:
set_brk(current->mm->start_brk, current->mm->brk);
- retval = ia32_setup_arg_pages(bprm, IA32_STACK_TOP, EXSTACK_DEFAULT);
+ retval = setup_arg_pages(bprm, IA32_STACK_TOP, EXSTACK_DEFAULT);
if (retval < 0) {
/* Someone check-me: is this error path enough? */
send_sig(SIGKILL, current, 0);
diff --git a/arch/x86_64/ia32/ia32_binfmt.c b/arch/x86_64/ia32/ia32_binfmt.c
index 185399b..ed56a88 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 { \
@@ -286,61 +283,6 @@ static void elf32_init(struct pt_regs *regs)
me->thread.es = __USER_DS;
}
-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;
-}
-EXPORT_SYMBOL(ia32_setup_arg_pages);
-
#ifdef CONFIG_SYSCTL
/* Register vsyscall32 into the ABI table */
#include <linux/sysctl.h>
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