Message ID | 20230218205341.3180300-1-vitalybuka@google.com |
---|---|
State | New |
Headers | show |
Series | stdlib: Undo post review change to 16adc58e73f3 [BZ #27749] | expand |
On 18/02/23 17:53, Vitaly Buka wrote: > Post review removal of "goto restart" from > https://sourceware.org/pipermail/libc-alpha/2021-April/125470.html > introduced a bug when some atexit handers skipped. > > Signed-off-by: Vitaly Buka <vitalybuka@google.com> LGTM, thanks. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> > --- > stdlib/Makefile | 1 + > stdlib/exit.c | 7 +++- > stdlib/test-atexit-recursive.c | 75 ++++++++++++++++++++++++++++++++++ > 3 files changed, 81 insertions(+), 2 deletions(-) > create mode 100644 stdlib/test-atexit-recursive.c > > diff --git a/stdlib/Makefile b/stdlib/Makefile > index ff5096ad1b..cd32f53b56 100644 > --- a/stdlib/Makefile > +++ b/stdlib/Makefile > @@ -171,6 +171,7 @@ tests := \ > test-a64l \ > test-at_quick_exit-race \ > test-atexit-race \ > + test-atexit-recursive \ > test-bz22786 \ > test-canon \ > test-canon2 \ > diff --git a/stdlib/exit.c b/stdlib/exit.c > index 6b1eed6445..1cd0bdfe94 100644 > --- a/stdlib/exit.c > +++ b/stdlib/exit.c > @@ -51,7 +51,10 @@ __run_exit_handlers (int status, struct exit_function_list **listp, > exit (). */ > while (true) > { > - struct exit_function_list *cur = *listp; > + struct exit_function_list *cur; > + > + restart: > + cur = *listp; > > if (cur == NULL) > { > @@ -113,7 +116,7 @@ __run_exit_handlers (int status, struct exit_function_list **listp, > if (__glibc_unlikely (new_exitfn_called != __new_exitfn_called)) > /* The last exit function, or another thread, has registered > more exit functions. Start the loop over. */ > - continue; > + goto restart; > } > > *listp = cur->next; > diff --git a/stdlib/test-atexit-recursive.c b/stdlib/test-atexit-recursive.c > new file mode 100644 > index 0000000000..0596b9763b > --- /dev/null > +++ b/stdlib/test-atexit-recursive.c > @@ -0,0 +1,75 @@ > +/* Support file for atexit/exit, etc. race tests (BZ #27749). > + Copyright (C) 2023 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/>. */ > + > +/* Check that atexit handler registed from another handler still called. */ > + > +#include <stdio.h> > +#include <stdlib.h> > +#include <support/check.h> > +#include <support/xunistd.h> > +#include <sys/wait.h> > +#include <unistd.h> > + > +static void > +atexit_cb (void) > +{ > +} > + > +static void > +atexit_last (void) > +{ > + _exit (1); > +} > + > +static void > +atexit_recursive (void) > +{ > + atexit (&atexit_cb); > + atexit (&atexit_last); > +} > + > +_Noreturn static void > +test_and_exit (int count) > +{ > + for (int i = 0; i < count; ++i) > + atexit (&atexit_cb); > + atexit (&atexit_recursive); > + exit (0); > +} > + > +static int > +do_test (void) > +{ > + for (int i = 0; i < 100; ++i) > + if (xfork () == 0) > + test_and_exit (i); > + > + for (int i = 0; i < 100; ++i) > + { > + int status; > + xwaitpid (0, &status, 0); > + if (!WIFEXITED (status)) > + FAIL_EXIT1 ("Failed iterations %d", i); > + TEST_COMPARE (WEXITSTATUS (status), 1); > + } > + > + return 0; > +} > + > +#define TEST_FUNCTION do_test > +#include <support/test-driver.c>
diff --git a/stdlib/Makefile b/stdlib/Makefile index ff5096ad1b..cd32f53b56 100644 --- a/stdlib/Makefile +++ b/stdlib/Makefile @@ -171,6 +171,7 @@ tests := \ test-a64l \ test-at_quick_exit-race \ test-atexit-race \ + test-atexit-recursive \ test-bz22786 \ test-canon \ test-canon2 \ diff --git a/stdlib/exit.c b/stdlib/exit.c index 6b1eed6445..1cd0bdfe94 100644 --- a/stdlib/exit.c +++ b/stdlib/exit.c @@ -51,7 +51,10 @@ __run_exit_handlers (int status, struct exit_function_list **listp, exit (). */ while (true) { - struct exit_function_list *cur = *listp; + struct exit_function_list *cur; + + restart: + cur = *listp; if (cur == NULL) { @@ -113,7 +116,7 @@ __run_exit_handlers (int status, struct exit_function_list **listp, if (__glibc_unlikely (new_exitfn_called != __new_exitfn_called)) /* The last exit function, or another thread, has registered more exit functions. Start the loop over. */ - continue; + goto restart; } *listp = cur->next; diff --git a/stdlib/test-atexit-recursive.c b/stdlib/test-atexit-recursive.c new file mode 100644 index 0000000000..0596b9763b --- /dev/null +++ b/stdlib/test-atexit-recursive.c @@ -0,0 +1,75 @@ +/* Support file for atexit/exit, etc. race tests (BZ #27749). + Copyright (C) 2023 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/>. */ + +/* Check that atexit handler registed from another handler still called. */ + +#include <stdio.h> +#include <stdlib.h> +#include <support/check.h> +#include <support/xunistd.h> +#include <sys/wait.h> +#include <unistd.h> + +static void +atexit_cb (void) +{ +} + +static void +atexit_last (void) +{ + _exit (1); +} + +static void +atexit_recursive (void) +{ + atexit (&atexit_cb); + atexit (&atexit_last); +} + +_Noreturn static void +test_and_exit (int count) +{ + for (int i = 0; i < count; ++i) + atexit (&atexit_cb); + atexit (&atexit_recursive); + exit (0); +} + +static int +do_test (void) +{ + for (int i = 0; i < 100; ++i) + if (xfork () == 0) + test_and_exit (i); + + for (int i = 0; i < 100; ++i) + { + int status; + xwaitpid (0, &status, 0); + if (!WIFEXITED (status)) + FAIL_EXIT1 ("Failed iterations %d", i); + TEST_COMPARE (WEXITSTATUS (status), 1); + } + + return 0; +} + +#define TEST_FUNCTION do_test +#include <support/test-driver.c>
Post review removal of "goto restart" from https://sourceware.org/pipermail/libc-alpha/2021-April/125470.html introduced a bug when some atexit handers skipped. Signed-off-by: Vitaly Buka <vitalybuka@google.com> --- stdlib/Makefile | 1 + stdlib/exit.c | 7 +++- stdlib/test-atexit-recursive.c | 75 ++++++++++++++++++++++++++++++++++ 3 files changed, 81 insertions(+), 2 deletions(-) create mode 100644 stdlib/test-atexit-recursive.c