From 8d8ae5eebd2c81064cfe88d877940ea4e6046d16 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Wed, 20 Dec 2023 07:34:42 -0800 Subject: [PATCH] Add a setjmp/longjmp test between user contexts Verify that setjmp and longjmp work correctly between user contexts. Arrange stacks for uctx_func1 and uctx_func2 so that ____longjmp_chk works when setjmp and longjmp are called from different user contexts. Reviewed-by: Noah Goldstein --- stdlib/Makefile | 1 + stdlib/tst-swapcontext2.c | 138 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 139 insertions(+) create mode 100644 stdlib/tst-swapcontext2.c diff --git a/stdlib/Makefile b/stdlib/Makefile index d0173d06a4..f166ec6c80 100644 --- a/stdlib/Makefile +++ b/stdlib/Makefile @@ -256,6 +256,7 @@ tests := \ tst-strtol-locale \ tst-strtoll \ tst-swapcontext1 \ + tst-swapcontext2 \ tst-thread-quick_exit \ tst-tininess \ tst-unsetenv1 \ diff --git a/stdlib/tst-swapcontext2.c b/stdlib/tst-swapcontext2.c new file mode 100644 index 0000000000..f679755649 --- /dev/null +++ b/stdlib/tst-swapcontext2.c @@ -0,0 +1,138 @@ +/* Check setjmp/longjmp between user contexts. + 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 + . */ + +#include +#include +#include +#include +#include + +static ucontext_t uctx_main, uctx_func1, uctx_func2; +const char *str1 = "\e[31mswapcontext(&uctx_func1, &uctx_main)\e[0m"; +const char *str2 = "\e[34mswapcontext(&uctx_func2, &uctx_main)\e[0m"; +const char *fmt1 = "\e[31m"; +const char *fmt2 = "\e[34m"; +static jmp_buf jmpbuf; + +#define handle_error(msg) \ + do { perror(msg); exit(EXIT_FAILURE); } while (0) + +__attribute__((noinline, noclone)) +static void +func4(ucontext_t *uocp, ucontext_t *ucp, const char *str, const char *fmt) +{ + printf(" %sfunc4: %s\e[0m\n", fmt, str); + if (swapcontext(uocp, ucp) == -1) + handle_error("swapcontext"); + printf(" %sfunc4: returning\e[0m\n", fmt); +} + +__attribute__((noinline, noclone)) +static void +func3(ucontext_t *uocp, ucontext_t *ucp, const char *str, const char *fmt) +{ + printf(" %sfunc3: func4(uocp, ucp, str)\e[0m\n", fmt); + func4(uocp, ucp, str, fmt); + printf(" %sfunc3: returning\e[0m\n", fmt); +} + +__attribute__((noinline, noclone)) +static void +func1(void) +{ + while ( 1 ) + { + printf(" \e[31mfunc1: func3(&uctx_func1, &uctx_main, str1)\e[0m\n"); + if (setjmp (jmpbuf) != 0) + { + printf(" %sfunc1: from longjmp\e[0m\n", fmt1); + exit (EXIT_SUCCESS); + } + func3( &uctx_func1, &uctx_main, str1, fmt1); + } +} + +__attribute__((noinline, noclone)) +static void +func2(void) +{ + while ( 1 ) + { + printf(" \e[34mfunc2: func3(&uctx_func2, &uctx_main, str2)\e[0m\n"); + func3(&uctx_func2, &uctx_main, str2, fmt2); + printf(" %sfunc2: calling longjmp\e[0m\n", fmt2); + longjmp (jmpbuf, 1); + } +} + +static int +do_test (void) +{ + /* ____longjmp_chk has */ +#if 0 +#ifdef _STACK_GROWS_DOWN +#define called_from(this, saved) ((this) < (saved)) +#else +#define called_from(this, saved) ((this) > (saved)) +#endif + + /* If "env" is from a frame that called us, we're all set. */ + if (called_from(this_frame, saved_frame)) + __longjmp (env, val); +#endif + /* Arrange stacks for uctx_func1 and uctx_func2 so that called_from + is true when setjmp is called from uctx_func1 and longjmp is called + from uctx_func2. */ +#ifdef _STACK_GROWS_DOWN +# define UCTX_FUNC1_STACK 1 +# define UCTX_FUNC2_STACK 0 +#else +# define UCTX_FUNC1_STACK 0 +# define UCTX_FUNC2_STACK 1 +#endif + char func_stack[2][16384]; + int i; + + if (getcontext(&uctx_func1) == -1) + handle_error("getcontext"); + uctx_func1.uc_stack.ss_sp = func_stack[UCTX_FUNC1_STACK]; + uctx_func1.uc_stack.ss_size = sizeof (func_stack[UCTX_FUNC1_STACK]); + uctx_func1.uc_link = &uctx_main; + makecontext(&uctx_func1, func1, 0); + + if (getcontext(&uctx_func2) == -1) + handle_error("getcontext"); + uctx_func2.uc_stack.ss_sp = func_stack[UCTX_FUNC2_STACK]; + uctx_func2.uc_stack.ss_size = sizeof (func_stack[UCTX_FUNC2_STACK]); + uctx_func2.uc_link = &uctx_func1; + makecontext(&uctx_func2, func2, 0); + + for ( i = 0; i < 2; i++ ) + { + if (swapcontext(&uctx_main, &uctx_func1) == -1) + handle_error("swapcontext"); + printf(" \e[35mmain: swapcontext(&uctx_main, &uctx_func2)\n\e[0m"); + if (swapcontext(&uctx_main, &uctx_func2) == -1) + handle_error("swapcontext"); + printf(" \e[35mmain: swapcontext(&uctx_main, &uctx_func1)\n\e[0m"); + } + + exit(EXIT_FAILURE); +} + +#include