From: Daniel Borkmann <daniel@iogearbox•net>
To: William Tu <u9012063@gmail•com>,
Alexei Starovoitov <alexei.starovoitov@gmail•com>
Cc: Linux Kernel Network Developers <netdev@vger•kernel.org>
Subject: Re: [RFC PATCH net-next] bpf: fix potential percpu map overcopy to user.
Date: Thu, 20 Oct 2016 21:39:49 +0200 [thread overview]
Message-ID: <58091D85.9060701@iogearbox.net> (raw)
In-Reply-To: <CALDO+SZbWbMPFsj10hR3XEB1696s0ENRoBttrT5T3O=DQ445XQ@mail.gmail.com>
On 10/20/2016 08:41 PM, William Tu wrote:
> On Thu, Oct 20, 2016 at 9:58 AM, Alexei Starovoitov
> <alexei.starovoitov@gmail•com> wrote:
>> On Thu, Oct 20, 2016 at 06:04:38PM +0200, Daniel Borkmann wrote:
>>>
>>> diff --git a/tools/testing/selftests/bpf/test_maps.c b/tools/testing/selftests/bpf/test_maps.c
>>> index ee384f0..d4832e8 100644
>>> --- a/tools/testing/selftests/bpf/test_maps.c
>>> +++ b/tools/testing/selftests/bpf/test_maps.c
>>> @@ -25,6 +25,33 @@
>>>
>>> static int map_flags;
>>>
>>> +static unsigned int num_possible_cpus(void)
>>> +{
>>> + static const char *fcpu = "/sys/devices/system/cpu/possible";
>>> + unsigned int val, possible_cpus = 0;
>>> + char buff[128];
>>> + FILE *fp;
>>> +
>>> + fp = fopen(fcpu, "r");
>>> + if (!fp) {
>>> + printf("Failed to open %s: '%s'!\n", fcpu, strerror(errno));
>>> + exit(1);
>>> + }
>>> +
>>> + while (fgets(buff, sizeof(buff), fp)) {
>>> + if (sscanf(buff, "%*u-%u", &val) == 1)
>>> + possible_cpus = val;
>>> + }
>>
>> looks great to me.
>> Could you move it into bpf_sys.h or somehow make it common in libbpf
>> and reuse it in samples/bpf/ ?
>> Since quite a few samples need this fix as well.
Ahh, true.
>> Thanks!
>
> Looks good to me. I tested it and it works fine.
Okay, thanks. I'll fix that up, mid-term we should try and move most of
that over to kernel selftests/bpf, and reuse tools/lib/bpf/.
> Thanks!
> William
prev parent reply other threads:[~2016-10-20 19:39 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-16 16:41 [RFC PATCH net-next] bpf: fix potential percpu map overcopy to user William Tu
2016-10-19 0:50 ` Alexei Starovoitov
2016-10-19 5:31 ` William Tu
2016-10-19 10:05 ` Daniel Borkmann
2016-10-20 19:21 ` William Tu
2016-10-19 15:15 ` Daniel Borkmann
2016-10-20 16:04 ` Daniel Borkmann
2016-10-20 16:58 ` Alexei Starovoitov
2016-10-20 18:41 ` William Tu
2016-10-20 19:39 ` Daniel Borkmann [this message]
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