| Message ID | 20220531202810.3864051-1-adhemerval.zanella@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | nptl: Fix __libc_cleanup_pop_restore asynchronous restore (BZ#29214) | expand |
On Mai 31 2022, Adhemerval Zanella via Libc-alpha wrote: > diff --git a/sysdeps/pthread/tst-cancel30.c b/sysdeps/pthread/tst-cancel30.c > new file mode 100644 > index 0000000000..ef3f187e71 > --- /dev/null > +++ b/sysdeps/pthread/tst-cancel30.c > @@ -0,0 +1,75 @@ > +/* Check if printf like functions does not disable asynchronous cancellation > + mode (BZ#29214). > + > + Copyright (C) 2022 Free Software Foundation, Inc. > + This file is part of the GNU C Library. > + > + The GNU C Library is free software; you can redistribute it and/or > + modify it under the terms of the GNU Lesser General Public > + License as published by the Free Software Foundation; either > + version 2.1 of the License, or (at your option) any later version. > + > + The GNU C Library is distributed in the hope that it will be useful, > + but WITHOUT ANY WARRANTY; without even the implied warranty of > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + Lesser General Public License for more details. > + > + You should have received a copy of the GNU Lesser General Public > + License along with the GNU C Library; if not, see > + <https://www.gnu.org/licenses/>. */ > + > +#include <support/check.h> > +#include <support/xthread.h> > +#include <support/xstdio.h> > + > +static pthread_barrier_t b; > + > +static void * > +tf (void *arg) > +{ > + int old; > + > + TEST_COMPARE (pthread_setcanceltype (PTHREAD_CANCEL_ASYNCHRONOUS, NULL), 0); > + > + TEST_COMPARE (pthread_setcanceltype (PTHREAD_CANCEL_ASYNCHRONOUS, &old), 0); > + TEST_COMPARE (old, PTHREAD_CANCEL_ASYNCHRONOUS); > + > + /* Check if internal lock cleanup routines restore the cancellation type > + correctly. */ > + printf ("...\n"); > + TEST_COMPARE (pthread_setcanceltype (PTHREAD_CANCEL_ASYNCHRONOUS, &old), 0); > + TEST_COMPARE (old, PTHREAD_CANCEL_ASYNCHRONOUS); > + > + xpthread_barrier_wait (&b); > + > + /* Wait indefinitely for cancellation, which only works if asynchronous > + cancellation is enabled. */ > +#ifdef SYS_futex > + syscall (SYS_futex, &(int){0}, FUTEX_WAIT_PRIVATE, 0, NULL, NULL, 0); > +#else > + for (;;); > +#endif Should that handle SYS_futex_time64?
* Andreas Schwab via Libc-alpha: >> + /* Wait indefinitely for cancellation, which only works if asynchronous >> + cancellation is enabled. */ >> +#ifdef SYS_futex >> + syscall (SYS_futex, &(int){0}, FUTEX_WAIT_PRIVATE, 0, NULL, NULL, 0); >> +#else >> + for (;;); >> +#endif > > Should that handle SYS_futex_time64? syscall (SYS_pause) should be architecture-agnostic, and like any syscall-invoked system call, it's not a cancellation point. Thanks, Florian
On 07/06/2022 08:20, Florian Weimer via Libc-alpha wrote: > * Andreas Schwab via Libc-alpha: > >>> + /* Wait indefinitely for cancellation, which only works if asynchronous >>> + cancellation is enabled. */ >>> +#ifdef SYS_futex >>> + syscall (SYS_futex, &(int){0}, FUTEX_WAIT_PRIVATE, 0, NULL, NULL, 0); >>> +#else >>> + for (;;); >>> +#endif >> >> Should that handle SYS_futex_time64? Indeed, riscv32 for instance is using the loop instead. > > syscall (SYS_pause) should be architecture-agnostic, and like any > syscall-invoked system call, it's not a cancellation point. It is not in unfortunately: $ python3 ./sysdeps/unix/sysv/linux/glibcsyscalls.py query-syscall pause pause: defined: arm hppa i386 m68k microblaze mips/mips32 mips/mips64/n32 mips/mips64/n64 powerpc/powerpc32 powerpc/powerpc64 s390/s390-32 s390/s390-64 sh sparc/s parc32 sparc/sparc64 x86_64/64 x86_64/x32 undefined: aarch64 alpha arc csky ia64 nios2 or1k riscv/rv32 riscv/rv64 So we will need to use ppoll and also ppoll_time64. I think it would be better to add a libspport to abstract and use glibc internal definition that handle the ppoll/poll_time64 (since there is no need to handle the timeout here).
diff --git a/nptl/libc-cleanup.c b/nptl/libc-cleanup.c index c4a83591bf..2ce59388d4 100644 --- a/nptl/libc-cleanup.c +++ b/nptl/libc-cleanup.c @@ -57,7 +57,8 @@ __libc_cleanup_pop_restore (struct _pthread_cleanup_buffer *buffer) THREAD_SETMEM (self, cleanup, buffer->__prev); int cancelhandling = atomic_load_relaxed (&self->cancelhandling); - if (cancelhandling & CANCELTYPE_BITMASK) + if (buffer->__canceltype != PTHREAD_CANCEL_DEFERRED + && (cancelhandling & CANCELTYPE_BITMASK) == 0) { int newval; do diff --git a/sysdeps/pthread/Makefile b/sysdeps/pthread/Makefile index 8cebe7a784..7d1670da87 100644 --- a/sysdeps/pthread/Makefile +++ b/sysdeps/pthread/Makefile @@ -126,6 +126,7 @@ tests += tst-cnd-basic tst-mtx-trylock tst-cnd-broadcast \ tst-pthread-raise-blocked-self \ tst-pthread_kill-exited \ tst-pthread_kill-exiting \ + tst-cancel30 \ # tests tests-time64 += \ diff --git a/sysdeps/pthread/tst-cancel30.c b/sysdeps/pthread/tst-cancel30.c new file mode 100644 index 0000000000..ef3f187e71 --- /dev/null +++ b/sysdeps/pthread/tst-cancel30.c @@ -0,0 +1,75 @@ +/* Check if printf like functions does not disable asynchronous cancellation + mode (BZ#29214). + + Copyright (C) 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <support/check.h> +#include <support/xthread.h> +#include <support/xstdio.h> + +static pthread_barrier_t b; + +static void * +tf (void *arg) +{ + int old; + + TEST_COMPARE (pthread_setcanceltype (PTHREAD_CANCEL_ASYNCHRONOUS, NULL), 0); + + TEST_COMPARE (pthread_setcanceltype (PTHREAD_CANCEL_ASYNCHRONOUS, &old), 0); + TEST_COMPARE (old, PTHREAD_CANCEL_ASYNCHRONOUS); + + /* Check if internal lock cleanup routines restore the cancellation type + correctly. */ + printf ("...\n"); + TEST_COMPARE (pthread_setcanceltype (PTHREAD_CANCEL_ASYNCHRONOUS, &old), 0); + TEST_COMPARE (old, PTHREAD_CANCEL_ASYNCHRONOUS); + + xpthread_barrier_wait (&b); + + /* Wait indefinitely for cancellation, which only works if asynchronous + cancellation is enabled. */ +#ifdef SYS_futex + syscall (SYS_futex, &(int){0}, FUTEX_WAIT_PRIVATE, 0, NULL, NULL, 0); +#else + for (;;); +#endif + + return 0; +} + +static int +do_test (void) +{ + xpthread_barrier_init (&b, NULL, 2); + + pthread_t th = xpthread_create (NULL, tf, NULL); + + xpthread_barrier_wait (&b); + + xpthread_cancel (th); + + void *status = xpthread_join (th); + TEST_VERIFY (status == PTHREAD_CANCELED); + + return 0; +} + +/* There is no need to wait full TIMEOUT if asynchronous is not working. */ +#define TIMEOUT 3 +#include <support/test-driver.c>