Messages in this thread | | | Date | Mon, 13 Jan 2014 11:17:15 +0800 | From | Ren Qiaowei <> | Subject | Re: [PATCH 2/5] x86, mpx: hook #BR exception handler to allocate bound tables |
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On 01/12/2014 05:20 PM, Borislav Petkov wrote: > On Sun, Jan 12, 2014 at 05:20:00PM +0800, Qiaowei Ren wrote: >> +static bool allocate_bt(unsigned long bd_entry) >> +{ >> + unsigned long bt_size = 1UL << (MPX_L2_BITS+MPX_L2_SHIFT); >> + unsigned long bt_addr, old_val; >> + >> + bt_addr = sys_mmap_pgoff(0, bt_size, PROT_READ | PROT_WRITE, >> + MAP_ANONYMOUS | MAP_PRIVATE | MAP_POPULATE, -1, 0); > > Are we sure about this? We can do a possible memory allocation in > mmap_region() in this exception handler context. And yes, we do a > conditional_sti(), which makes it all the more susceptible. > > Have you run this with lockdep enabled? > Yes, I run this with lockdep enabled.
Thanks, Qiaowei
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