On 06/12, Srikar Dronamraju wrote: > > > > Note also that we should move this !UPROBE_COPY_INSN from > > install_breakpoint() to somewhere near alloc_uprobe(). This code > > is called only once, it looks a bit strange to use the "random" mm > > (the first mm vma_prio_tree_foreach() finds) and its mapping to > > verify the insn. In fact this is simply not correct and should be > > fixed, note that on x86 arch_uprobe_analyze_insn() checks > > The reason we "delay" the copy_insn to the first insert is because > we have to get access to mm. For archs like x86, we want to know if the > executable is 32 bit or not
Yes. And this is wrong afaics. Once again. This !UPROBE_COPY_INSN code is called only once, and it uses the "random" mm. After that install_breakpoint() just calls set_swbp(another_mm) while the insn can be invalid because another_mm->ia32_compat != mm->ia32_compat. > So in effect, if we get access to > struct file corresponding to the inode and if the inode corresponds to > 32 bit executable file or 64 bit executable file during register, then > we can move it around alloc_uprobe(). I don't think this can work. I have another simple fix in mind, I'll write another email later. Oleg. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
