diff --git a/libc/arch-arm/arm.mk b/libc/arch-arm/arm.mk index 00be4aed5..70cc8eba6 100644 --- a/libc/arch-arm/arm.mk +++ b/libc/arch-arm/arm.mk @@ -53,7 +53,6 @@ libc_bionic_src_files_arm += \ arch-arm/bionic/atomics_arm.c \ arch-arm/bionic/__bionic_clone.S \ arch-arm/bionic/_exit_with_stack_teardown.S \ - arch-arm/bionic/__get_sp.S \ arch-arm/bionic/libgcc_compat.c \ arch-arm/bionic/memcmp.S \ arch-arm/bionic/_setjmp.S \ diff --git a/libc/arch-arm/bionic/__get_sp.S b/libc/arch-arm/bionic/__get_sp.S deleted file mode 100644 index 9ae6f247f..000000000 --- a/libc/arch-arm/bionic/__get_sp.S +++ /dev/null @@ -1,34 +0,0 @@ -/* - * Copyright (C) 2008 The Android Open Source Project - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * * Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * * Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in - * the documentation and/or other materials provided with the - * distribution. - * - * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS - * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT - * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS - * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE - * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, - * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, - * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS - * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED - * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, - * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT - * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. - */ - -#include - -ENTRY_PRIVATE(__get_sp) - mov r0, sp - bx lr -END(__get_sp) diff --git a/libc/arch-arm64/arm64.mk b/libc/arch-arm64/arm64.mk index ed991ce60..6c4f6a6e8 100644 --- a/libc/arch-arm64/arm64.mk +++ b/libc/arch-arm64/arm64.mk @@ -29,7 +29,6 @@ libc_common_src_files_arm64 += \ libc_bionic_src_files_arm64 := \ arch-arm64/bionic/__bionic_clone.S \ arch-arm64/bionic/_exit_with_stack_teardown.S \ - arch-arm64/bionic/__get_sp.S \ arch-arm64/bionic/__rt_sigreturn.S \ arch-arm64/bionic/_setjmp.S \ arch-arm64/bionic/setjmp.S \ diff --git a/libc/arch-arm64/bionic/__get_sp.S b/libc/arch-arm64/bionic/__get_sp.S deleted file mode 100644 index d5e88e973..000000000 --- a/libc/arch-arm64/bionic/__get_sp.S +++ /dev/null @@ -1,34 +0,0 @@ -/* - * Copyright (C) 2013 The Android Open Source Project - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * * Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * * Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in - * the documentation and/or other materials provided with the - * distribution. - * - * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS - * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT - * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS - * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE - * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, - * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, - * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS - * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED - * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, - * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT - * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. - */ - -#include - -ENTRY_PRIVATE(__get_sp) - mov x0, sp - ret -END(__get_sp) diff --git a/libc/arch-mips/bionic/__get_sp.S b/libc/arch-mips/bionic/__get_sp.S deleted file mode 100644 index 5f5d32ef7..000000000 --- a/libc/arch-mips/bionic/__get_sp.S +++ /dev/null @@ -1,34 +0,0 @@ -/* - * Copyright (C) 2008 The Android Open Source Project - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * * Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * * Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in - * the documentation and/or other materials provided with the - * distribution. - * - * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS - * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT - * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS - * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE - * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, - * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, - * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS - * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED - * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, - * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT - * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. - */ - -#include - -ENTRY_PRIVATE(__get_sp) - move v0, sp - j ra -END(__get_sp) diff --git a/libc/arch-mips/mips.mk b/libc/arch-mips/mips.mk index 8e415f957..31a1f32fd 100644 --- a/libc/arch-mips/mips.mk +++ b/libc/arch-mips/mips.mk @@ -54,7 +54,6 @@ libc_bionic_src_files_mips += \ arch-mips/bionic/bzero.S \ arch-mips/bionic/cacheflush.cpp \ arch-mips/bionic/_exit_with_stack_teardown.S \ - arch-mips/bionic/__get_sp.S \ arch-mips/bionic/_setjmp.S \ arch-mips/bionic/setjmp.S \ arch-mips/bionic/sigsetjmp.S \ diff --git a/libc/arch-mips64/bionic/__get_sp.S b/libc/arch-mips64/bionic/__get_sp.S deleted file mode 100644 index 5f5d32ef7..000000000 --- a/libc/arch-mips64/bionic/__get_sp.S +++ /dev/null @@ -1,34 +0,0 @@ -/* - * Copyright (C) 2008 The Android Open Source Project - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * * Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * * Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in - * the documentation and/or other materials provided with the - * distribution. - * - * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS - * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT - * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS - * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE - * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, - * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, - * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS - * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED - * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, - * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT - * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. - */ - -#include - -ENTRY_PRIVATE(__get_sp) - move v0, sp - j ra -END(__get_sp) diff --git a/libc/arch-x86/bionic/__get_sp.S b/libc/arch-x86/bionic/__get_sp.S deleted file mode 100644 index aea6ac62c..000000000 --- a/libc/arch-x86/bionic/__get_sp.S +++ /dev/null @@ -1,34 +0,0 @@ -/* - * Copyright (C) 2008 The Android Open Source Project - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * * Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * * Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in - * the documentation and/or other materials provided with the - * distribution. - * - * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS - * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT - * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS - * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE - * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, - * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, - * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS - * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED - * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, - * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT - * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. - */ - -#include - -ENTRY_PRIVATE(__get_sp) - mov %esp, %eax - ret -END(__get_sp) diff --git a/libc/arch-x86/x86.mk b/libc/arch-x86/x86.mk index 019dc8e81..a14154866 100644 --- a/libc/arch-x86/x86.mk +++ b/libc/arch-x86/x86.mk @@ -25,7 +25,6 @@ libc_bionic_src_files_x86 := \ libc_bionic_src_files_x86 += \ arch-x86/bionic/__bionic_clone.S \ arch-x86/bionic/_exit_with_stack_teardown.S \ - arch-x86/bionic/__get_sp.S \ arch-x86/bionic/_setjmp.S \ arch-x86/bionic/setjmp.S \ arch-x86/bionic/__set_tls.c \ diff --git a/libc/arch-x86_64/bionic/__get_sp.S b/libc/arch-x86_64/bionic/__get_sp.S deleted file mode 100644 index 49a2406e7..000000000 --- a/libc/arch-x86_64/bionic/__get_sp.S +++ /dev/null @@ -1,34 +0,0 @@ -/* - * Copyright (C) 2013 The Android Open Source Project - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * * Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * * Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in - * the documentation and/or other materials provided with the - * distribution. - * - * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS - * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT - * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS - * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE - * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, - * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, - * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS - * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED - * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, - * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT - * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. - */ - -#include - -ENTRY_PRIVATE(__get_sp) - mov %rsp, %rax - ret -END(__get_sp) diff --git a/libc/arch-x86_64/x86_64.mk b/libc/arch-x86_64/x86_64.mk index 7887c519e..b001b5e98 100644 --- a/libc/arch-x86_64/x86_64.mk +++ b/libc/arch-x86_64/x86_64.mk @@ -30,7 +30,6 @@ libc_common_src_files_x86_64 += \ libc_bionic_src_files_x86_64 := \ arch-x86_64/bionic/__bionic_clone.S \ arch-x86_64/bionic/_exit_with_stack_teardown.S \ - arch-x86_64/bionic/__get_sp.S \ arch-x86_64/bionic/__rt_sigreturn.S \ arch-x86_64/bionic/_setjmp.S \ arch-x86_64/bionic/setjmp.S \ diff --git a/libc/bionic/libc_init_common.cpp b/libc/bionic/libc_init_common.cpp index 9e4eecde4..950073a29 100644 --- a/libc/bionic/libc_init_common.cpp +++ b/libc/bionic/libc_init_common.cpp @@ -36,7 +36,6 @@ #include #include #include -#include #include #include "private/bionic_auxv.h" @@ -46,7 +45,6 @@ #include "pthread_internal.h" extern "C" abort_msg_t** __abort_message_ptr; -extern "C" uintptr_t __get_sp(void); extern "C" int __system_properties_init(void); extern "C" int __set_tls(void* ptr); extern "C" int __set_tid_address(int* tid_address); @@ -62,17 +60,6 @@ char** environ; // Declared in "private/bionic_ssp.h". uintptr_t __stack_chk_guard = 0; -static size_t get_main_thread_stack_size() { - rlimit stack_limit; - int rlimit_result = getrlimit(RLIMIT_STACK, &stack_limit); - if ((rlimit_result == 0) && - (stack_limit.rlim_cur != RLIM_INFINITY) && - (stack_limit.rlim_cur > PTHREAD_STACK_MIN)) { - return (stack_limit.rlim_cur & ~(PAGE_SIZE - 1)); - } - return PTHREAD_STACK_SIZE_DEFAULT; -} - /* Init TLS for the initial thread. Called by the linker _before_ libc is mapped * in memory. Beware: all writes to libc globals from this function will * apply to linker-private copies and will not be visible from libc later on. @@ -96,16 +83,15 @@ void __libc_init_tls(KernelArgumentBlock& args) { main_thread.tid = __set_tid_address(&main_thread.tid); main_thread.set_cached_pid(main_thread.tid); - // Work out the extent of the main thread's stack. - uintptr_t stack_top = (__get_sp() & ~(PAGE_SIZE - 1)) + PAGE_SIZE; - size_t stack_size = get_main_thread_stack_size(); - void* stack_bottom = reinterpret_cast(stack_top - stack_size); - // We don't want to free the main thread's stack even when the main thread exits // because things like environment variables with global scope live on it. + // We also can't free the pthread_internal_t itself, since that lives on the main + // thread's stack rather than on the heap. pthread_attr_init(&main_thread.attr); - pthread_attr_setstack(&main_thread.attr, stack_bottom, stack_size); main_thread.attr.flags = PTHREAD_ATTR_FLAG_USER_ALLOCATED_STACK | PTHREAD_ATTR_FLAG_MAIN_THREAD; + main_thread.attr.guard_size = 0; // The main thread has no guard page. + main_thread.attr.stack_size = 0; // User code should never see this; we'll compute it when asked. + // TODO: the main thread's sched_policy and sched_priority need to be queried. __init_thread(&main_thread, false); __init_tls(&main_thread); diff --git a/libc/bionic/pthread_attr.cpp b/libc/bionic/pthread_attr.cpp index e1cd85365..8df3bffac 100644 --- a/libc/bionic/pthread_attr.cpp +++ b/libc/bionic/pthread_attr.cpp @@ -28,6 +28,13 @@ #include +#include +#include +#include + +#include "private/bionic_string_utils.h" +#include "private/ErrnoRestorer.h" +#include "private/libc_logging.h" #include "pthread_internal.h" int pthread_attr_init(pthread_attr_t* attr) { @@ -90,8 +97,8 @@ int pthread_attr_setstacksize(pthread_attr_t* attr, size_t stack_size) { } int pthread_attr_getstacksize(const pthread_attr_t* attr, size_t* stack_size) { - *stack_size = attr->stack_size; - return 0; + void* unused; + return pthread_attr_getstack(attr, &unused, stack_size); } int pthread_attr_setstack(pthread_attr_t* attr, void* stack_base, size_t stack_size) { @@ -106,7 +113,42 @@ int pthread_attr_setstack(pthread_attr_t* attr, void* stack_base, size_t stack_s return 0; } +static int __pthread_attr_getstack_main_thread(void** stack_base, size_t* stack_size) { + ErrnoRestorer errno_restorer; + + // It doesn't matter which thread we are; we're just looking for "[stack]". + FILE* fp = fopen("/proc/self/maps", "re"); + if (fp == NULL) { + return errno; + } + char line[BUFSIZ]; + while (fgets(line, sizeof(line), fp) != NULL) { + if (ends_with(line, " [stack]\n")) { + uintptr_t lo, hi; + if (sscanf(line, "%" SCNxPTR "-%" SCNxPTR, &lo, &hi) == 2) { + *stack_base = reinterpret_cast(lo); + *stack_size = hi - lo; + + // Does our current RLIMIT_STACK mean we won't actually get everything /proc/maps promises? + rlimit stack_limit; + if (getrlimit(RLIMIT_STACK, &stack_limit) != -1) { + if (*stack_size > stack_limit.rlim_cur) { + *stack_size = stack_limit.rlim_cur; + } + } + + fclose(fp); + return 0; + } + } + } + __libc_fatal("No [stack] line found in /proc/self/maps!"); +} + int pthread_attr_getstack(const pthread_attr_t* attr, void** stack_base, size_t* stack_size) { + if ((attr->flags & PTHREAD_ATTR_FLAG_MAIN_THREAD) != 0) { + return __pthread_attr_getstack_main_thread(stack_base, stack_size); + } *stack_base = attr->stack_base; *stack_size = attr->stack_size; return 0; @@ -122,9 +164,8 @@ int pthread_attr_getguardsize(const pthread_attr_t* attr, size_t* guard_size) { return 0; } -int pthread_getattr_np(pthread_t thid, pthread_attr_t* attr) { - pthread_internal_t* thread = (pthread_internal_t*) thid; - *attr = thread->attr; +int pthread_getattr_np(pthread_t t, pthread_attr_t* attr) { + *attr = reinterpret_cast(t)->attr; return 0; } diff --git a/libc/private/bionic_string_utils.h b/libc/private/bionic_string_utils.h new file mode 100644 index 000000000..ab0eccf02 --- /dev/null +++ b/libc/private/bionic_string_utils.h @@ -0,0 +1,31 @@ +/* + * Copyright (C) 2014 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#ifndef _BIONIC_STRING_UTILS_H_ +#define _BIONIC_STRING_UTILS_H_ + +#include + +static inline bool ends_with(const char* s1, const char* s2) { + size_t s1_length = strlen(s1); + size_t s2_length = strlen(s2); + if (s2_length > s1_length) { + return false; + } + return memcmp(s1 + (s1_length - s2_length), s2, s2_length) == 0; +} + +#endif // _BIONIC_STRING_UTILS_H_ diff --git a/tests/dlfcn_test.cpp b/tests/dlfcn_test.cpp index c2c9286f6..457fcd5c0 100644 --- a/tests/dlfcn_test.cpp +++ b/tests/dlfcn_test.cpp @@ -188,10 +188,8 @@ TEST(dlfcn, dladdr) { // Look in /proc/pid/maps to find out what address we were loaded at. // TODO: factor /proc/pid/maps parsing out into a class and reuse all over bionic. void* base_address = NULL; - char path[PATH_MAX]; - snprintf(path, sizeof(path), "/proc/%d/maps", getpid()); char line[BUFSIZ]; - FILE* fp = fopen(path, "r"); + FILE* fp = fopen("/proc/self/maps", "r"); ASSERT_TRUE(fp != NULL); while (fgets(line, sizeof(line), fp) != NULL) { uintptr_t start = strtoul(line, 0, 16); diff --git a/tests/pthread_test.cpp b/tests/pthread_test.cpp index 5328e48cf..5f74e388d 100644 --- a/tests/pthread_test.cpp +++ b/tests/pthread_test.cpp @@ -23,6 +23,7 @@ #include #include #include +#include #include #include @@ -816,3 +817,88 @@ TEST(pthread, pthread_mutex_timedlock) { ASSERT_EQ(0, pthread_mutex_unlock(&m)); ASSERT_EQ(0, pthread_mutex_destroy(&m)); } + +TEST(pthread, pthread_attr_getstack__main_thread) { + // This test is only meaningful for the main thread, so make sure we're running on it! + ASSERT_EQ(getpid(), syscall(__NR_gettid)); + + // Get the main thread's attributes. + pthread_attr_t attributes; + ASSERT_EQ(0, pthread_getattr_np(pthread_self(), &attributes)); + + // Check that we correctly report that the main thread has no guard page. + size_t guard_size; + ASSERT_EQ(0, pthread_attr_getguardsize(&attributes, &guard_size)); + ASSERT_EQ(0U, guard_size); // The main thread has no guard page. + + // Get the stack base and the stack size (both ways). + void* stack_base; + size_t stack_size; + ASSERT_EQ(0, pthread_attr_getstack(&attributes, &stack_base, &stack_size)); + size_t stack_size2; + ASSERT_EQ(0, pthread_attr_getstacksize(&attributes, &stack_size2)); + + // The two methods of asking for the stack size should agree. + EXPECT_EQ(stack_size, stack_size2); + + // What does /proc/self/maps' [stack] line say? + void* maps_stack_base = NULL; + size_t maps_stack_size = 0; + FILE* fp = fopen("/proc/self/maps", "r"); + ASSERT_TRUE(fp != NULL); + char line[BUFSIZ]; + while (fgets(line, sizeof(line), fp) != NULL) { + uintptr_t lo, hi; + char name[10]; + sscanf(line, "%" PRIxPTR "-%" PRIxPTR " %*4s %*x %*x:%*x %*d %10s", &lo, &hi, name); + if (strcmp(name, "[stack]") == 0) { + maps_stack_base = reinterpret_cast(lo); + maps_stack_size = hi - lo; + break; + } + } + fclose(fp); + +#if defined(__BIONIC__) + // bionic thinks that the stack base and size should correspond to the mapped region. + EXPECT_EQ(maps_stack_base, stack_base); + EXPECT_EQ(maps_stack_size, stack_size); +#else + // glibc doesn't give the true extent for some reason. +#endif + + // Both bionic and glibc agree that the high address you can compute from the returned + // values should match what /proc/self/maps says. + void* stack_end = reinterpret_cast(stack_base) + stack_size; + void* maps_stack_end = reinterpret_cast(maps_stack_base) + maps_stack_size; + EXPECT_EQ(maps_stack_end, stack_end); + + // + // What if the rlimit is smaller than the stack's current extent? + // + rlimit rl; + rl.rlim_cur = rl.rlim_max = 1024; // 1KiB. We know the stack must be at least a page already. + rl.rlim_max = RLIM_INFINITY; + ASSERT_EQ(0, setrlimit(RLIMIT_STACK, &rl)); + + ASSERT_EQ(0, pthread_getattr_np(pthread_self(), &attributes)); + ASSERT_EQ(0, pthread_attr_getstack(&attributes, &stack_base, &stack_size)); + ASSERT_EQ(0, pthread_attr_getstacksize(&attributes, &stack_size2)); + + EXPECT_EQ(stack_size, stack_size2); + ASSERT_EQ(1024U, stack_size); + + // + // What if the rlimit isn't a whole number of pages? + // + rl.rlim_cur = rl.rlim_max = 6666; // Not a whole number of pages. + rl.rlim_max = RLIM_INFINITY; + ASSERT_EQ(0, setrlimit(RLIMIT_STACK, &rl)); + + ASSERT_EQ(0, pthread_getattr_np(pthread_self(), &attributes)); + ASSERT_EQ(0, pthread_attr_getstack(&attributes, &stack_base, &stack_size)); + ASSERT_EQ(0, pthread_attr_getstacksize(&attributes, &stack_size2)); + + EXPECT_EQ(stack_size, stack_size2); + ASSERT_EQ(6666U, stack_size); +}