Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1307940

Re: [PATCH] arm64: Allow vmalloc regions to be set with set_memory_*

From Daniel Borkmann <daniel@iogearbox.net>
Newsgroups linux.kernel
Subject Re: [PATCH] arm64: Allow vmalloc regions to be set with set_memory_*
Date 2016-01-13 01:40 +0100
Message-ID <qQhDH-cE-5@gated-at.bofh.it> (permalink)
References <qQeZc-6Mv-11@gated-at.bofh.it> <qQhaF-8s7-1@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


On 01/13/2016 01:01 AM, Alexei Starovoitov wrote:
> On Tue, Jan 12, 2016 at 01:46:27PM -0800, Laura Abbott wrote:
>>
>> The range of set_memory_* is currently restricted to the module address
>> range because of difficulties in breaking down larger block sizes.
>> vmalloc maps PAGE_SIZE pages so it is safe to use as well. Update the
>> function ranges and add a comment explaining why the range is restricted
>> the way it is.
>>
>> Signed-off-by: Laura Abbott <labbott@fedoraproject.org>
>> ---
>> This should let the protections for the eBPF work as expected, I don't
>> know if there is some sort of self test for thatL.
>
> you can test it with:
> # sysctl net.core.bpf_jit_enable=1
> # insmod test_bpf.ko
>
> On x64 it shows:
> test_bpf: Summary: 291 PASSED, 0 FAILED, [282/283 JIT'ed]
>
> arm64 may have less JIT'ed tests.

Also, in that lib/test_bpf.c file, you can do a test by overwriting/'corrupting'
part of the fp->insnsi instructions right after bpf_prog_select_runtime(fp) to
see if setting the bpf_prog as RO works.

Thanks,
Daniel

Back to linux.kernel | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

[PATCH] arm64: Allow vmalloc regions to be set with set_memory_* Laura Abbott <labbott@fedoraproject.org> - 2016-01-12 22:50 +0100
  Re: [PATCH] arm64: Allow vmalloc regions to be set with set_memory_* Alexei Starovoitov <alexei.starovoitov@gmail.com> - 2016-01-13 01:10 +0100
    Re: [PATCH] arm64: Allow vmalloc regions to be set with set_memory_* Daniel Borkmann <daniel@iogearbox.net> - 2016-01-13 01:40 +0100
  Re: [PATCH] arm64: Allow vmalloc regions to be set with set_memory_* Ard Biesheuvel <ard.biesheuvel@linaro.org> - 2016-01-13 15:10 +0100
    Re: [PATCH] arm64: Allow vmalloc regions to be set with set_memory_* Ard Biesheuvel <ard.biesheuvel@linaro.org> - 2016-01-13 17:20 +0100
      Re: [PATCH] arm64: Allow vmalloc regions to be set with set_memory_* Laura Abbott <labbott@redhat.com> - 2016-01-15 00:10 +0100

csiph-web