Messages in this thread | | | Subject | Re: [PATCH][v4] uprobes/x86: emulate push insns for uprobe on x86 | From | Yonghong Song <> | Date | Mon, 27 Nov 2017 10:06:16 -0800 |
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Hi, Ingo and Peter,
This patch has been reviewed by Oleg Nesterov. Could you take a look and help merge it upstream?
Thanks!
Yonghong
On 11/20/17 10:25 AM, Yonghong Song wrote: > > > On 11/20/17 8:41 AM, Oleg Nesterov wrote: >> On 11/17, Yonghong Song wrote: >>> >>> On 11/17/17 9:25 AM, Oleg Nesterov wrote: >>>> On 11/15, Yonghong Song wrote: >>>>> >>>>> v3 -> v4: >>>>> . Revert most of v3 change as 32bit emulation is not really working >>>>> on x86_64 platform as among other issues, function >>>>> emulate_push_stack() >>>>> needs to account for 32bit app on 64bit platform. >>>>> A separate effort is ongoing to address this issue. >>>> >>>> Reviewed-by: Oleg Nesterov <oleg@redhat.com> >>>> >>>> >>>> >>>> Please test your patch with the fix below, in this particular case the >>>> TIF_IA32 check should be fine. Although this is not what we really >>>> want, >>>> we should probably use user_64bit_mode(regs) which checks ->cs. But >>>> this >>>> needs more changes and doesn't solve other problems (get_unmapped_area) >>>> so I still can't decide what should we do right now... >>> >>> I tested the below change with my patch. On x86_64, both 64bit and 32bit >>> program can be uprobe emulated properly. >> >> Good, so your patch is fine. > > Thanks! > >> >>> On x86_32, however, there is a >>> compilation error like below: >> >> Yes, yes, when I said "in this particular case" I meant x86_64 system >> only. >> >> Sorry for confusion, I asked you to test this additional change just to >> ensure that we didn't miss something and your patch has no problems with >> 32bit tasks on 64bit system, except those we need to fix anyway. > > Understood. I actually tried a little to see whether I could have a > simple way to fix 32bit compilation error without using ugly "#ifdef > CONFIG_X86_64". Maybe is_64bit_mm is a good choice. But we could defer > this until you have a comprehensive fix for 32bit app uprobe on 64bit > systems as there are multiple issues for this. > >> >> Oleg. >>
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