lkml.org 
[lkml]   [2011]   [Nov]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 2/5] uprobes: introduce uprobe_switch_to()
From
Date
On Mon, 2011-11-28 at 20:06 +0100, Oleg Nesterov wrote:
> +void uprobe_switch_to(struct task_struct *curr)
> +{
> + struct uprobe_task *utask = curr->utask;
> + struct pt_regs *regs = task_pt_regs(curr);
> +
> + if (!utask || utask->state != UTASK_SSTEP)
> + return;
> +
> + if (!(regs->flags & X86_EFLAGS_TF))
> + return;
> +
> + set_xol_ip(regs);
> +}

> void __weak set_xol_ip(struct pt_regs *regs)
> {
> + int cpu = smp_processor_id();
> + struct uprobe_task *utask = current->utask;
> + struct uprobe *uprobe = utask->active_uprobe;
> +
> + memcpy(uprobe_xol_slots[cpu], uprobe->insn, MAX_UINSN_BYTES);
> +
> + utask->xol_vaddr = fix_to_virt(UPROBE_XOL_FIRST_PAGE)
> + + UPROBES_XOL_SLOT_BYTES * cpu;
> + set_instruction_pointer(regs, utask->xol_vaddr);
> }

So uprobe_switch_to() will always reset the IP to the start of the slot?
That sounds wrong, things like the RIP relative stuff needs multiple
instructions.




\
 
 \ /
  Last update: 2011-11-28 20:57    [W:0.149 / U:5.896 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site