Commit 81aac3a1 authored by Prakash Sangappa's avatar Prakash Sangappa Committed by Linus Torvalds

userfaultfd: selftest: add tests for UFFD_FEATURE_SIGBUS feature

Add tests for UFFD_FEATURE_SIGBUS feature.  The tests will verify signal
delivery instead of userfault events.  Also, test use of UFFDIO_COPY to
allocate memory and retry accessing monitored area after signal
delivery.

Also fix a bug in uffd_poll_thread() where 'uffd' is leaked.

Link: http://lkml.kernel.org/r/1501552446-748335-3-git-send-email-prakash.sangappa@oracle.comSigned-off-by: default avatarPrakash Sangappa <prakash.sangappa@oracle.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 2d6d6f5a
......@@ -66,6 +66,7 @@
#include <sys/wait.h>
#include <pthread.h>
#include <linux/userfaultfd.h>
#include <setjmp.h>
#ifdef __NR_userfaultfd
......@@ -408,6 +409,7 @@ static void *uffd_poll_thread(void *arg)
userfaults++;
break;
case UFFD_EVENT_FORK:
close(uffd);
uffd = msg.arg.fork.ufd;
pollfd[0].fd = uffd;
break;
......@@ -572,6 +574,17 @@ static int userfaultfd_open(int features)
return 0;
}
sigjmp_buf jbuf, *sigbuf;
static void sighndl(int sig, siginfo_t *siginfo, void *ptr)
{
if (sig == SIGBUS) {
if (sigbuf)
siglongjmp(*sigbuf, 1);
abort();
}
}
/*
* For non-cooperative userfaultfd test we fork() a process that will
* generate pagefaults, will mremap the area monitored by the
......@@ -585,19 +598,59 @@ 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), signal_test = 1, we register
* monitored area, generate pagefaults and test that signal is delivered.
* Use UFFDIO_COPY to allocate missing page and retry. For signal_test = 2
* test robustness use case - we release monitored area, fork a process
* that will generate pagefaults and verify signal is generated.
* This also tests UFFD_FEATURE_EVENT_FORK event along with the signal
* feature. Using monitor thread, verify no userfault events are generated.
*/
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;
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));
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) {
fprintf(stderr, "Signal repeated\n");
return 1;
}
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 +660,9 @@ static int faulting_process(void)
}
}
if (signal_test)
return signalled != split_nr_pages;
if (test_type == TEST_HUGETLB)
return 0;
......@@ -761,7 +817,7 @@ static int userfaultfd_events_test(void)
perror("fork"), exit(1);
if (!pid)
return faulting_process();
return faulting_process(0);
waitpid(pid, &err, 0);
if (err)
......@@ -778,6 +834,70 @@ static int userfaultfd_events_test(void)
return userfaults != nr_pages;
}
static int userfaultfd_sig_test(void)
{
struct uffdio_register uffdio_register;
unsigned long expected_ioctls;
unsigned long userfaults;
pthread_t uffd_mon;
int err, features;
pid_t pid;
char c;
printf("testing signal delivery: ");
fflush(stdout);
if (uffd_test_ops->release_pages(area_dst))
return 1;
features = UFFD_FEATURE_EVENT_FORK|UFFD_FEATURE_SIGBUS;
if (userfaultfd_open(features) < 0)
return 1;
fcntl(uffd, F_SETFL, uffd_flags | O_NONBLOCK);
uffdio_register.range.start = (unsigned long) area_dst;
uffdio_register.range.len = nr_pages * page_size;
uffdio_register.mode = UFFDIO_REGISTER_MODE_MISSING;
if (ioctl(uffd, UFFDIO_REGISTER, &uffdio_register))
fprintf(stderr, "register failure\n"), exit(1);
expected_ioctls = uffd_test_ops->expected_ioctls;
if ((uffdio_register.ioctls & expected_ioctls) !=
expected_ioctls)
fprintf(stderr,
"unexpected missing ioctl for anon memory\n"),
exit(1);
if (faulting_process(1))
fprintf(stderr, "faulting process failed\n"), exit(1);
if (uffd_test_ops->release_pages(area_dst))
return 1;
if (pthread_create(&uffd_mon, &attr, uffd_poll_thread, NULL))
perror("uffd_poll_thread create"), exit(1);
pid = fork();
if (pid < 0)
perror("fork"), exit(1);
if (!pid)
exit(faulting_process(2));
waitpid(pid, &err, 0);
if (err)
fprintf(stderr, "faulting process failed\n"), exit(1);
if (write(pipefd[1], &c, sizeof(c)) != sizeof(c))
perror("pipe write"), exit(1);
if (pthread_join(uffd_mon, (void **)&userfaults))
return 1;
printf("done.\n");
printf(" Signal test userfaults: %ld\n", userfaults);
close(uffd);
return userfaults != 0;
}
static int userfaultfd_stress(void)
{
void *area;
......@@ -946,7 +1066,8 @@ static int userfaultfd_stress(void)
return err;
close(uffd);
return userfaultfd_zeropage_test() || userfaultfd_events_test();
return userfaultfd_zeropage_test() || userfaultfd_sig_test()
|| userfaultfd_events_test();
}
/*
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment