From: Benjamin Herrenschmidt Date: Wed, 1 Mar 2006 00:59:19 +0000 (-0800) Subject: [PATCH] Add mm->task_size and fix powerpc vdso X-Git-Tag: v2.6.16-rc6~144 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0551fbd29e16fccd46e41b7d01bf0f8f39b14212;p=linux-2.6 [PATCH] Add mm->task_size and fix powerpc vdso This patch adds mm->task_size to keep track of the task size of a given mm and uses that to fix the powerpc vdso so that it uses the mm task size to decide what pages to fault in instead of the current thread flags (which broke when ptracing). (akpm: I expect that mm_struct.task_size will become the way in which we finally sort out the confusion between 32-bit processes and 32-bit mm's. It may need tweaks, but at this stage this patch is powerpc-only.) Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c index f0c47dab09..04f7df39ff 100644 --- a/arch/powerpc/kernel/vdso.c +++ b/arch/powerpc/kernel/vdso.c @@ -182,8 +182,8 @@ static struct page * vdso_vma_nopage(struct vm_area_struct * vma, unsigned long offset = address - vma->vm_start; struct page *pg; #ifdef CONFIG_PPC64 - void *vbase = test_thread_flag(TIF_32BIT) ? - vdso32_kbase : vdso64_kbase; + void *vbase = (vma->vm_mm->task_size > TASK_SIZE_USER32) ? + vdso64_kbase : vdso32_kbase; #else void *vbase = vdso32_kbase; #endif diff --git a/fs/exec.c b/fs/exec.c index 0e1c95074d..0b515ac531 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -885,6 +885,12 @@ int flush_old_exec(struct linux_binprm * bprm) current->flags &= ~PF_RANDOMIZE; flush_thread(); + /* Set the new mm task size. We have to do that late because it may + * depend on TIF_32BIT which is only updated in flush_thread() on + * some architectures like powerpc + */ + current->mm->task_size = TASK_SIZE; + if (bprm->e_uid != current->euid || bprm->e_gid != current->egid || file_permission(bprm->file, MAY_READ) || (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP)) { diff --git a/include/linux/sched.h b/include/linux/sched.h index b6f51e3a38..ff2e09c953 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -298,8 +298,9 @@ struct mm_struct { unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags); void (*unmap_area) (struct mm_struct *mm, unsigned long addr); - unsigned long mmap_base; /* base of mmap area */ - unsigned long cached_hole_size; /* if non-zero, the largest hole below free_area_cache */ + unsigned long mmap_base; /* base of mmap area */ + unsigned long task_size; /* size of task vm space */ + unsigned long cached_hole_size; /* if non-zero, the largest hole below free_area_cache */ unsigned long free_area_cache; /* first hole of size cached_hole_size or larger */ pgd_t * pgd; atomic_t mm_users; /* How many users with user space? */