Subject: [merged] blackfin-ptrace-call-find_vma-with-the-mmap_sem-held.patch removed from -mm tree To: davidlohr@xxxxxx,realmz6@xxxxxxxxx,mm-commits@xxxxxxxxxxxxxxx From: akpm@xxxxxxxxxxxxxxxxxxxx Date: Mon, 09 Jun 2014 12:39:58 -0700 The patch titled Subject: blackfin/ptrace: call find_vma with the mmap_sem held has been removed from the -mm tree. Its filename was blackfin-ptrace-call-find_vma-with-the-mmap_sem-held.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Davidlohr Bueso <davidlohr@xxxxxx> Subject: blackfin/ptrace: call find_vma with the mmap_sem held Performing vma lookups without taking the mm->mmap_sem is asking for trouble. While doing the search, the vma in question can be modified or even removed before returning to the caller. Take the lock (shared) in order to avoid races while iterating through the vmacache and/or rbtree. Signed-off-by: Davidlohr Bueso <davidlohr@xxxxxx> Cc: Steven Miao <realmz6@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/blackfin/kernel/ptrace.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff -puN arch/blackfin/kernel/ptrace.c~blackfin-ptrace-call-find_vma-with-the-mmap_sem-held arch/blackfin/kernel/ptrace.c --- a/arch/blackfin/kernel/ptrace.c~blackfin-ptrace-call-find_vma-with-the-mmap_sem-held +++ a/arch/blackfin/kernel/ptrace.c @@ -117,6 +117,7 @@ put_reg(struct task_struct *task, unsign int is_user_addr_valid(struct task_struct *child, unsigned long start, unsigned long len) { + bool valid; struct vm_area_struct *vma; struct sram_list_struct *sraml; @@ -124,9 +125,12 @@ is_user_addr_valid(struct task_struct *c if (start + len < start) return -EIO; + down_read(&child->mm->mmap_sem); vma = find_vma(child->mm, start); - if (vma && start >= vma->vm_start && start + len <= vma->vm_end) - return 0; + valid = vma && start >= vma->vm_start && start + len <= vma->vm_end; + up_read(&child->mm->mmap_sem); + if (valid) + return 0; for (sraml = child->mm->context.sram_list; sraml; sraml = sraml->next) if (start >= (unsigned long)sraml->addr _ Patches currently in -mm which might be from davidlohr@xxxxxx are origin.patch m68k-call-find_vma-with-the-mmap_sem-held-in-sys_cacheflush.patch linux-next.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html