diff options
| -rw-r--r-- | ChangeLog | 7 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/x86/Makefile | 7 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/x86/tst-cet-setcontext-1.c | 127 |
3 files changed, 141 insertions, 0 deletions
diff --git a/ChangeLog b/ChangeLog index f6aa73550b..0694ff3f24 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,10 @@ +2018-07-25 H.J. Lu <hongjiu.lu@intel.com> + + * sysdeps/unix/sysv/linux/x86/Makefile (tests): Add + tst-cet-setcontext-1 if CET is enabled. + (CFLAGS-tst-cet-setcontext-1.c): Add -mshstk. + * sysdeps/unix/sysv/linux/x86/tst-cet-setcontext-1.c: New file. + 2018-07-25 Adhemerval Zanella <adhemerval.zanella@linaro.org> * include/threads.h: Move to ... diff --git a/sysdeps/unix/sysv/linux/x86/Makefile b/sysdeps/unix/sysv/linux/x86/Makefile index 111ff9ff58..a30fdb1dc1 100644 --- a/sysdeps/unix/sysv/linux/x86/Makefile +++ b/sysdeps/unix/sysv/linux/x86/Makefile @@ -23,3 +23,10 @@ endif ifeq ($(subdir),setjmp) tests += tst-saved_mask-1 endif + +ifeq ($(enable-cet),yes) +ifeq ($(subdir),stdlib) +tests += tst-cet-setcontext-1 +CFLAGS-tst-cet-setcontext-1.c += -mshstk +endif +endif diff --git a/sysdeps/unix/sysv/linux/x86/tst-cet-setcontext-1.c b/sysdeps/unix/sysv/linux/x86/tst-cet-setcontext-1.c new file mode 100644 index 0000000000..ecf86a9e16 --- /dev/null +++ b/sysdeps/unix/sysv/linux/x86/tst-cet-setcontext-1.c @@ -0,0 +1,127 @@ +/* Check getcontext and setcontext on the context from makecontext + with shadow stack. + Copyright (C) 2018 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 + <http://www.gnu.org/licenses/>. */ + +#include <stdio.h> +#include <stdint.h> +#include <stdlib.h> +#include <ucontext.h> +#include <unistd.h> +#include <sys/mman.h> +#include <stdatomic.h> +#include <x86intrin.h> + +static ucontext_t ctx[5]; +static atomic_int done; + +static void +__attribute__((noinline, noclone)) +f2 (void) +{ + printf ("start f2\n"); + done++; + if (setcontext (&ctx[2]) != 0) + { + printf ("%s: setcontext: %m\n", __FUNCTION__); + exit (EXIT_FAILURE); + } +} + +static void +f1 (void) +{ + printf ("start f1\n"); + if (getcontext (&ctx[2]) != 0) + { + printf ("%s: getcontext: %m\n", __FUNCTION__); + exit (EXIT_FAILURE); + } + if (done) + exit (EXIT_SUCCESS); + f2 (); +} + +static int +do_test (void) +{ + char st1[32768]; + puts ("making contexts"); + if (getcontext (&ctx[0]) != 0) + { + printf ("%s: getcontext: %m\n", __FUNCTION__); + exit (EXIT_FAILURE); + } + if (getcontext (&ctx[1]) != 0) + { + printf ("%s: getcontext: %m\n", __FUNCTION__); + exit (EXIT_FAILURE); + } + + ctx[3].uc_stack.ss_sp = st1; + ctx[3].uc_stack.ss_size = sizeof st1; + ctx[3].uc_link = &ctx[0]; + makecontext (&ctx[3], (void (*) (void)) f1, 0); + + ctx[1].uc_stack.ss_sp = st1; + ctx[1].uc_stack.ss_size = sizeof st1; + ctx[1].uc_link = &ctx[0]; + makecontext (&ctx[1], (void (*) (void)) f1, 0); + + ctx[4].uc_stack.ss_sp = st1; + ctx[4].uc_stack.ss_size = sizeof st1; + ctx[4].uc_link = &ctx[0]; + makecontext (&ctx[4], (void (*) (void)) f1, 0); + + /* NB: When shadow stack is enabled, makecontext calls arch_prctl + with ARCH_CET_ALLOC_SHSTK to allocate a new shadow stack which + can be unmapped. The base address and size of the new shadow + stack are returned in __ssp[1] and __ssp[2]. makecontext is + called for CTX1, CTX3 and CTX4. But only CTX1 is used. New + shadow stacks are allocated in the order of CTX3, CTX1, CTX4. + It is very likely that CTX1's shadow stack is placed between + CTX3 and CTX4. We munmap CTX3's and CTX4's shadow stacks to + create gaps above and below CTX1's shadow stack. We check + that setcontext CTX1 works correctly in this case. */ + if (_get_ssp () != 0) + { + if (ctx[3].__ssp[1] != 0 + && munmap ((void *) (uintptr_t) ctx[3].__ssp[1], + (size_t) ctx[3].__ssp[2]) != 0) + { + printf ("%s: munmap: %m\n", __FUNCTION__); + exit (EXIT_FAILURE); + } + + if (ctx[4].__ssp[1] != 0 + && munmap ((void *) (uintptr_t) ctx[4].__ssp[1], + (size_t) ctx[4].__ssp[2]) != 0) + { + printf ("%s: munmap: %m\n", __FUNCTION__); + exit (EXIT_FAILURE); + } + } + + if (setcontext (&ctx[1]) != 0) + { + printf ("%s: setcontext: %m\n", __FUNCTION__); + exit (EXIT_FAILURE); + } + exit (EXIT_FAILURE); +} + +#include <support/test-driver.c> |