On 06/07, Srikar Dronamraju wrote:
>
> +static int write_opcode(struct task_struct *tsk, struct uprobe * uprobe,
> + unsigned long vaddr, uprobe_opcode_t opcode)
> +{
> + struct page *old_page, *new_page;
> + void *vaddr_old, *vaddr_new;
> + struct vm_area_struct *vma;
> + unsigned long addr;
> + int ret;
> +
> + /* Read the page with vaddr into memory */
> + ret = get_user_pages(tsk, tsk->mm, vaddr, 1, 1, 1, &old_page, &vma);
Sorry if this was already discussed... But why we are using FOLL_WRITE here?
We are not going to write into this page, and this provokes the unnecessary
cow, no?
Also. This is called under down_read(mmap_sem), can't we race with
access_process_vm() modifying the same memory?
Oleg.
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