lkml.org 
[lkml]   [2017]   [Jul]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [RESEND PATCH 2/2] userfaultfd: selftest: Add tests for UFFD_FREATURE_SIGBUS
From
Date


On 7/26/17 12:53 AM, Mike Rapoport wrote:
>> +
>> /*
>> * For non-cooperative userfaultfd test we fork() a process that will
>> * generate pagefaults, will mremap the area monitored by the
>> @@ -585,19 +598,54 @@ static int userfaultfd_open(int features)
>> * The release of the pages currently generates event for shmem and
>> * anonymous memory (UFFD_EVENT_REMOVE), hence it is not checked
>> * for hugetlb.
>> + * For signal test(UFFD_FEATURE_SIGBUS), primarily test signal
>> + * delivery and ensure no userfault events are generated.
> Can you add some details about the tests? E.g. what is the meaning if
> signal_test=1 and signal_test=2 and what is the difference between them?

Ok, I will.

>
>> */
>> -static int faulting_process(void)
>> +static int faulting_process(int signal_test)
>> {
>> unsigned long nr;
>> unsigned long long count;
>> unsigned long split_nr_pages;
>> + unsigned long lastnr;
>> + struct sigaction act;
>> + unsigned long signalled=0, sig_repeats = 0;
> Spaces around that '=' ^

Will fix it.
>
>> if (test_type != TEST_HUGETLB)
>> split_nr_pages = (nr_pages + 1) / 2;
>> else
>> split_nr_pages = nr_pages;
>>
>> + if (signal_test) {
>> + sigbuf = &jbuf;
>> + memset (&act, 0, sizeof(act));
> There should be no space between function name and open parenthesis.

ok
>
>> + act.sa_sigaction = sighndl;
>> + act.sa_flags = SA_SIGINFO;
>> + if (sigaction(SIGBUS, &act, 0)) {
>> + perror("sigaction");
>> + return 1;
>> + }
>> + lastnr = (unsigned long)-1;
>> + }
>> +
>> for (nr = 0; nr < split_nr_pages; nr++) {
>> + if (signal_test) {
>> + if (sigsetjmp(*sigbuf, 1) != 0) {
>> + if (nr == lastnr) {
>> + sig_repeats++;
>> + continue;
> If I understand correctly, when nr == lastnr we get a repeated signal for
> the same page and this is an error, right?

Yes,

> Why would we continue the test and won't return error immediately?

Yes, it could just return error. I will fix it.
>
>> + }
>> +
>> + lastnr = nr;
>> + if (signal_test == 1) {
>> + if (copy_page(uffd, nr * page_size))
>> + signalled++;
>> + } else {
>> + signalled++;
>> + continue;
>> + }
>> + }
>> + }
>> +
>> count = *area_count(area_dst, nr);
>> if (count != count_verify[nr]) {
>> fprintf(stderr,
>> @@ -607,6 +655,8 @@ static int faulting_process(void)
>> }
>> }
>>
>> + if (signal_test)
>> + return signalled != split_nr_pages || sig_repeats != 0;
> I believe return !(signalled == split_nr_pages && sig_repeats == 0) is
> clearer.
> And I blank line after the return statement would be nice :)

Ok.
Will send out v2 patch with the changes.

Thanks,
-Prakash


\
 
 \ /
  Last update: 2017-07-26 20:55    [W:0.074 / U:29.632 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site