| Message ID | 1512756476-2452-1-git-send-email-vgupta@synopsys.com |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [uclibc-ng-devel,v2] Fix subtle race in tst-cancel2 / tst-cancelx2 | expand |
On 12/08/2017 10:07 AM, Vineet Gupta wrote: > When ran on ARC, these tests would ocassionally fail > > | [ARCLinux]# for i in 1 2 3 4 5 ; do ./tst-cancel2; echo $?; done > | write succeeded > | result is wrong: expected 0xffffffff, got 0x1 > | 1 <-- fail > | 0 <-- pass > | 0 <--- pass > | 0 <-- pass > | write succeeded > | result is wrong: expected 0xffffffff, got 0x1 > | 1 <-- fail > > Same test (which originated form glibc) doesn't fail in glibc builds. > Turns out there's a subtle race in uclibc version > > The test creates a new thread, makes it do a looong write call, and > parent then cancels the thread, expecting it to unwind out of write > call cleanly. However the write (even for 10k bytes) could finish > before parent gets a chance to resume and/or cancel it, causing the > occasional failure. > > Fix this subtelty by making it write not just once but forever. > > Cc: Cupertino Miranda <cmiranda@synopsys.com> > Signed-off-by: Vineet Gupta <vgupta@synopsys.com> > --- > Change since v1: fix typos in changelogs > --- Ping ? > test/nptl/tst-cancel2.c | 6 +----- > 1 file changed, 1 insertion(+), 5 deletions(-) > > diff --git a/test/nptl/tst-cancel2.c b/test/nptl/tst-cancel2.c > index 45c9e8ea957a..08dd13b10f37 100644 > --- a/test/nptl/tst-cancel2.c > +++ b/test/nptl/tst-cancel2.c > @@ -32,11 +32,7 @@ tf (void *arg) > write blocks. */ > char buf[100000]; > > - if (write (fd[1], buf, sizeof (buf)) == sizeof (buf)) > - { > - puts ("write succeeded"); > - return (void *) 1l; > - } > + while (write (fd[1], buf, sizeof (buf)) > 0); > > return (void *) 42l; > } >
Hi, patch applied and pushed, just forgot the mail, best regards Waldemar > Am 18.12.2017 um 20:18 schrieb Vineet Gupta <Vineet.Gupta1@synopsys.com>: > >> On 12/08/2017 10:07 AM, Vineet Gupta wrote: >> When ran on ARC, these tests would ocassionally fail >> | [ARCLinux]# for i in 1 2 3 4 5 ; do ./tst-cancel2; echo $?; done >> | write succeeded >> | result is wrong: expected 0xffffffff, got 0x1 >> | 1 <-- fail >> | 0 <-- pass >> | 0 <--- pass >> | 0 <-- pass >> | write succeeded >> | result is wrong: expected 0xffffffff, got 0x1 >> | 1 <-- fail >> Same test (which originated form glibc) doesn't fail in glibc builds. >> Turns out there's a subtle race in uclibc version >> The test creates a new thread, makes it do a looong write call, and >> parent then cancels the thread, expecting it to unwind out of write >> call cleanly. However the write (even for 10k bytes) could finish >> before parent gets a chance to resume and/or cancel it, causing the >> occasional failure. >> Fix this subtelty by making it write not just once but forever. >> Cc: Cupertino Miranda <cmiranda@synopsys.com> >> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> >> --- >> Change since v1: fix typos in changelogs >> --- > > Ping ? > > >> test/nptl/tst-cancel2.c | 6 +----- >> 1 file changed, 1 insertion(+), 5 deletions(-) >> diff --git a/test/nptl/tst-cancel2.c b/test/nptl/tst-cancel2.c >> index 45c9e8ea957a..08dd13b10f37 100644 >> --- a/test/nptl/tst-cancel2.c >> +++ b/test/nptl/tst-cancel2.c >> @@ -32,11 +32,7 @@ tf (void *arg) >> write blocks. */ >> char buf[100000]; >> - if (write (fd[1], buf, sizeof (buf)) == sizeof (buf)) >> - { >> - puts ("write succeeded"); >> - return (void *) 1l; >> - } >> + while (write (fd[1], buf, sizeof (buf)) > 0); >> return (void *) 42l; >> } >
diff --git a/test/nptl/tst-cancel2.c b/test/nptl/tst-cancel2.c index 45c9e8ea957a..08dd13b10f37 100644 --- a/test/nptl/tst-cancel2.c +++ b/test/nptl/tst-cancel2.c @@ -32,11 +32,7 @@ tf (void *arg) write blocks. */ char buf[100000]; - if (write (fd[1], buf, sizeof (buf)) == sizeof (buf)) - { - puts ("write succeeded"); - return (void *) 1l; - } + while (write (fd[1], buf, sizeof (buf)) > 0); return (void *) 42l; }
When ran on ARC, these tests would ocassionally fail | [ARCLinux]# for i in 1 2 3 4 5 ; do ./tst-cancel2; echo $?; done | write succeeded | result is wrong: expected 0xffffffff, got 0x1 | 1 <-- fail | 0 <-- pass | 0 <--- pass | 0 <-- pass | write succeeded | result is wrong: expected 0xffffffff, got 0x1 | 1 <-- fail Same test (which originated form glibc) doesn't fail in glibc builds. Turns out there's a subtle race in uclibc version The test creates a new thread, makes it do a looong write call, and parent then cancels the thread, expecting it to unwind out of write call cleanly. However the write (even for 10k bytes) could finish before parent gets a chance to resume and/or cancel it, causing the occasional failure. Fix this subtelty by making it write not just once but forever. Cc: Cupertino Miranda <cmiranda@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> --- Change since v1: fix typos in changelogs --- test/nptl/tst-cancel2.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-)