Message ID | 20231214193703.238374-3-hjl.tools@gmail.com |
---|---|
State | New |
Headers | show |
Series | Add tests for longjmp with user contexts | expand |
On Thu, Dec 14, 2023 at 1:37 PM H.J. Lu <hjl.tools@gmail.com> wrote: > > Verify that setjmp/longjmp works correctly within a user context. > --- > stdlib/Makefile | 1 + > stdlib/tst-setcontext11.c | 178 ++++++++++++++++++++++++++++++++++++++ > 2 files changed, 179 insertions(+) > create mode 100644 stdlib/tst-setcontext11.c > > diff --git a/stdlib/Makefile b/stdlib/Makefile > index 8c6249aab4..0b5ef699a2 100644 > --- a/stdlib/Makefile > +++ b/stdlib/Makefile > @@ -235,6 +235,7 @@ tests := \ > tst-setcontext8 \ > tst-setcontext9 \ > tst-setcontext10 \ > + tst-setcontext11 \ > tst-strfmon_l \ > tst-strfrom \ > tst-strfrom-locale \ > diff --git a/stdlib/tst-setcontext11.c b/stdlib/tst-setcontext11.c > new file mode 100644 > index 0000000000..5f5df5b81b > --- /dev/null > +++ b/stdlib/tst-setcontext11.c > @@ -0,0 +1,178 @@ > +/* Check setjmp/longjmp within user context. > + 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/>. */ > + > +#include <errno.h> > +#include <stdio.h> > +#include <stdlib.h> > +#include <string.h> > +#include <setjmp.h> > +#include <ucontext.h> > +#include <unistd.h> > + > +static ucontext_t ctx[3]; > +static jmp_buf jmpbuf; > + > +static int was_in_f1; > +static int was_in_f2; > +static int longjmp_called; > + > +static char st2[32768]; > + > +static void > +f1 (int a0, int a1, int a2, int a3) > +{ > + printf ("start f1(a0=%x,a1=%x,a2=%x,a3=%x)\n", a0, a1, a2, a3); > + > + if (a0 != 1 || a1 != 2 || a2 != 3 || a3 != -4) > + { > + puts ("arg mismatch"); > + exit (EXIT_FAILURE); > + } > + > + if (swapcontext (&ctx[1], &ctx[2]) != 0) > + { > + printf ("%s: swapcontext: %m\n", __FUNCTION__); > + exit (EXIT_FAILURE); > + } > + puts ("finish f1"); > + was_in_f1 = 1; > +} > + > +static void > +__attribute__ ((noinline, noclone)) > +call_longjmp (void) > +{ > + longjmp_called = 1; > + longjmp (jmpbuf, 1); > +} > + > +static void > +f2 (void) > +{ > + if (!longjmp_called) > + { > + if (setjmp (jmpbuf) == 0) > + call_longjmp (); > + } > + > + puts ("start f2"); > + if (swapcontext (&ctx[2], &ctx[1]) != 0) > + { > + printf ("%s: swapcontext: %m\n", __FUNCTION__); > + exit (EXIT_FAILURE); > + } > + puts ("finish f2"); > + was_in_f2 = 1; > +} > + > +volatile int global; > +static int back_in_main; > + > +static void > +check_called (void) > +{ > + if (back_in_main == 0) > + { > + puts ("program did not reach main again"); > + _exit (EXIT_FAILURE); > + } > +} > + > +static int > +do_test (void) > +{ > + atexit (check_called); > + > + char st1[32768]; > + > + puts ("making contexts"); > + if (getcontext (&ctx[1]) != 0) > + { > + if (errno == ENOSYS) > + { > + back_in_main = 1; > + exit (EXIT_SUCCESS); > + } > + > + printf ("%s: getcontext: %m\n", __FUNCTION__); > + exit (EXIT_FAILURE); > + } > + > + /* Play some tricks with this context. */ > + if (++global == 1) > + if (setcontext (&ctx[1]) != 0) > + { > + printf ("%s: setcontext: %m\n", __FUNCTION__); > + exit (EXIT_FAILURE); > + } > + if (global != 2) > + { > + printf ("%s: 'global' not incremented twice\n", __FUNCTION__); > + exit (EXIT_FAILURE); > + } > + > + ctx[1].uc_stack.ss_sp = st1; > + ctx[1].uc_stack.ss_size = sizeof st1; > + ctx[1].uc_link = &ctx[0]; > + { > + ucontext_t tempctx = ctx[1]; > + makecontext (&ctx[1], (void (*) (void)) f1, 4, 1, 2, 3, -4); > + > + /* Without this check, a stub makecontext can make us spin forever. */ > + if (memcmp (&tempctx, &ctx[1], sizeof ctx[1]) == 0) > + { > + puts ("makecontext was a no-op, presuming not implemented"); > + return 0; > + } > + } > + > + if (getcontext (&ctx[2]) != 0) > + { > + printf ("%s: second getcontext: %m\n", __FUNCTION__); > + exit (EXIT_FAILURE); > + } > + ctx[2].uc_stack.ss_sp = st2; > + ctx[2].uc_stack.ss_size = sizeof st2; > + ctx[2].uc_link = &ctx[1]; > + makecontext (&ctx[2], f2, 0); > + > + puts ("swapping contexts"); > + if (swapcontext (&ctx[0], &ctx[2]) != 0) > + { > + printf ("%s: swapcontext: %m\n", __FUNCTION__); > + exit (EXIT_FAILURE); > + } > + puts ("back at main program"); > + back_in_main = 1; > + > + if (was_in_f1 == 0) > + { > + puts ("didn't reach f1"); > + exit (EXIT_FAILURE); > + } > + if (was_in_f2 == 0) > + { > + puts ("didn't reach f2"); > + exit (EXIT_FAILURE); > + } > + > + puts ("test succeeded"); > + return 0; > +} > + > +#include <support/test-driver.c> > -- > 2.43.0 > LGTM. Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
diff --git a/stdlib/Makefile b/stdlib/Makefile index 8c6249aab4..0b5ef699a2 100644 --- a/stdlib/Makefile +++ b/stdlib/Makefile @@ -235,6 +235,7 @@ tests := \ tst-setcontext8 \ tst-setcontext9 \ tst-setcontext10 \ + tst-setcontext11 \ tst-strfmon_l \ tst-strfrom \ tst-strfrom-locale \ diff --git a/stdlib/tst-setcontext11.c b/stdlib/tst-setcontext11.c new file mode 100644 index 0000000000..5f5df5b81b --- /dev/null +++ b/stdlib/tst-setcontext11.c @@ -0,0 +1,178 @@ +/* Check setjmp/longjmp within user context. + 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/>. */ + +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <setjmp.h> +#include <ucontext.h> +#include <unistd.h> + +static ucontext_t ctx[3]; +static jmp_buf jmpbuf; + +static int was_in_f1; +static int was_in_f2; +static int longjmp_called; + +static char st2[32768]; + +static void +f1 (int a0, int a1, int a2, int a3) +{ + printf ("start f1(a0=%x,a1=%x,a2=%x,a3=%x)\n", a0, a1, a2, a3); + + if (a0 != 1 || a1 != 2 || a2 != 3 || a3 != -4) + { + puts ("arg mismatch"); + exit (EXIT_FAILURE); + } + + if (swapcontext (&ctx[1], &ctx[2]) != 0) + { + printf ("%s: swapcontext: %m\n", __FUNCTION__); + exit (EXIT_FAILURE); + } + puts ("finish f1"); + was_in_f1 = 1; +} + +static void +__attribute__ ((noinline, noclone)) +call_longjmp (void) +{ + longjmp_called = 1; + longjmp (jmpbuf, 1); +} + +static void +f2 (void) +{ + if (!longjmp_called) + { + if (setjmp (jmpbuf) == 0) + call_longjmp (); + } + + puts ("start f2"); + if (swapcontext (&ctx[2], &ctx[1]) != 0) + { + printf ("%s: swapcontext: %m\n", __FUNCTION__); + exit (EXIT_FAILURE); + } + puts ("finish f2"); + was_in_f2 = 1; +} + +volatile int global; +static int back_in_main; + +static void +check_called (void) +{ + if (back_in_main == 0) + { + puts ("program did not reach main again"); + _exit (EXIT_FAILURE); + } +} + +static int +do_test (void) +{ + atexit (check_called); + + char st1[32768]; + + puts ("making contexts"); + if (getcontext (&ctx[1]) != 0) + { + if (errno == ENOSYS) + { + back_in_main = 1; + exit (EXIT_SUCCESS); + } + + printf ("%s: getcontext: %m\n", __FUNCTION__); + exit (EXIT_FAILURE); + } + + /* Play some tricks with this context. */ + if (++global == 1) + if (setcontext (&ctx[1]) != 0) + { + printf ("%s: setcontext: %m\n", __FUNCTION__); + exit (EXIT_FAILURE); + } + if (global != 2) + { + printf ("%s: 'global' not incremented twice\n", __FUNCTION__); + exit (EXIT_FAILURE); + } + + ctx[1].uc_stack.ss_sp = st1; + ctx[1].uc_stack.ss_size = sizeof st1; + ctx[1].uc_link = &ctx[0]; + { + ucontext_t tempctx = ctx[1]; + makecontext (&ctx[1], (void (*) (void)) f1, 4, 1, 2, 3, -4); + + /* Without this check, a stub makecontext can make us spin forever. */ + if (memcmp (&tempctx, &ctx[1], sizeof ctx[1]) == 0) + { + puts ("makecontext was a no-op, presuming not implemented"); + return 0; + } + } + + if (getcontext (&ctx[2]) != 0) + { + printf ("%s: second getcontext: %m\n", __FUNCTION__); + exit (EXIT_FAILURE); + } + ctx[2].uc_stack.ss_sp = st2; + ctx[2].uc_stack.ss_size = sizeof st2; + ctx[2].uc_link = &ctx[1]; + makecontext (&ctx[2], f2, 0); + + puts ("swapping contexts"); + if (swapcontext (&ctx[0], &ctx[2]) != 0) + { + printf ("%s: swapcontext: %m\n", __FUNCTION__); + exit (EXIT_FAILURE); + } + puts ("back at main program"); + back_in_main = 1; + + if (was_in_f1 == 0) + { + puts ("didn't reach f1"); + exit (EXIT_FAILURE); + } + if (was_in_f2 == 0) + { + puts ("didn't reach f2"); + exit (EXIT_FAILURE); + } + + puts ("test succeeded"); + return 0; +} + +#include <support/test-driver.c>