| Message ID | CAFEAcA_s1C3md4Vw6fQu2GLy=hZBLDSrvnHppQswL8+K1giLwg@mail.gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 16.02.2018 11:15, Peter Maydell wrote: > On 16 February 2018 at 06:12, Thomas Huth <thuth@redhat.com> wrote: >> Commit 92b540dac9fc3a5 introduce a counter to handle the timeouts in a >> better way. But in case ccnt reaches 512, the current read character is >> ignored - and if that character is part of the string that we are looking >> for, the test fails to match the string. >> >> Almost all of the tests look for a string within the first 512 bytes of >> firmware output, so the problem never triggered there. But the hppa test >> that has been added recently looks for a longer string at the very end of >> a long output, thus there's a chance that we miss a character there so >> that the test fails unexpectedly. Fix it by *not* reading and dropping a >> character if the counter reaches 512. >> >> Fixes: 92b540dac9fc3a572c7342edd0b073000f5a6abf >> Signed-off-by: Thomas Huth <thuth@redhat.com> >> --- >> @Peter: Since this fixes the problem with running "make check", could >> you maybe apply this directly to the master branch? Thanks, and sorry >> for the inconvenience! >> >> tests/boot-serial-test.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/tests/boot-serial-test.c b/tests/boot-serial-test.c >> index ea87a80..696f7a3 100644 >> --- a/tests/boot-serial-test.c >> +++ b/tests/boot-serial-test.c >> @@ -101,7 +101,7 @@ static void check_guest_output(const testdef_t *test, int fd) >> /* Poll serial output... Wait at most 60 seconds */ >> for (i = 0; i < 6000; ++i) { >> ccnt = 0; >> - while ((nbr = read(fd, &ch, 1)) == 1 && ccnt++ < 512) { >> + while (ccnt++ < 512 && (nbr = read(fd, &ch, 1)) == 1) { >> if (ch == test->expect[pos]) { >> pos += 1; >> if (test->expect[pos] == '\0') { > > I did a test build with this, but OpenBSD's compiler > now complains: > > /home/qemu/tests/boot-serial-test.c: In function 'test_machine': > /usr/local/include/glib-2.0/glib/gmacros.h:370:7: warning: 'nbr' may > be used uninitialized in this function [-Wmaybe-uninitialized] > if (expr) \ > ^ > /home/qemu/tests/boot-serial-test.c:114:12: note: 'nbr' was declared here > int i, nbr, pos = 0, ccnt; > ^ > > This is obviously a false positive, but we can silence it by > --- a/tests/boot-serial-test.c > +++ b/tests/boot-serial-test.c > @@ -111,7 +111,7 @@ static testdef_t tests[] = { > static void check_guest_output(const testdef_t *test, int fd) > { > bool output_ok = false; > - int i, nbr, pos = 0, ccnt; > + int i, nbr = 0, pos = 0, ccnt; > char ch; > > /* Poll serial output... Wait at most 60 seconds */ > > so I'll just squash that change in if that's ok? Sure! Thanks, Thomas PS: I think the OpenBSD compiler is wrong here, nbr should get initialized at least once before the g_assert(nbr >= 0) check ...
On 16 February 2018 at 10:25, Thomas Huth <thuth@redhat.com> wrote: > PS: I think the OpenBSD compiler is wrong here, nbr should get > initialized at least once before the g_assert(nbr >= 0) check ... Yes, I agree, but it does require some intelligence on the part of the compiler to figure out that the ccnt++ < 512 condition can't trigger first time round the loop. (It's a gcc 4.9.3, so presumably newer gcc are indeed smarter.) Applied to master. thanks -- PMM
--- a/tests/boot-serial-test.c +++ b/tests/boot-serial-test.c @@ -111,7 +111,7 @@ static testdef_t tests[] = { static void check_guest_output(const testdef_t *test, int fd) { bool output_ok = false; - int i, nbr, pos = 0, ccnt; + int i, nbr = 0, pos = 0, ccnt; char ch; /* Poll serial output... Wait at most 60 seconds */