a493fe4153
GWP-ASan's recoverable mode was landed upstream in https://reviews.llvm.org/D140173. This mode allows for a use-after-free or a buffer-overflow bug to be detected by GWP-ASan, a crash report dumped, but then GWP-ASan (through the preCrashReport() and postCrashReportRecoverableOnly() hooks) will patch up the memory so that the process can continue, in spite of the memory safety bug. This is desirable, as it allows us to consider migrating non-system apps from opt-in GWP-ASan to opt-out GWP-ASan. The major concern was "if we make it opt-out, then bad apps will start crashing". If we don't crash, problem solved :). Obviously, we'll need to do this with an amount of process sampling to mitigate against the 70KiB memory overhead. The biggest problem is that the debuggerd signal handler isn't the first signal handler for apps, it's the sigchain handler inside of libart. Clearly, the sigchain handler needs to ask us whether the crash is GWP-ASan's fault, and if so, please patch up the allocator. Because of linker namespace restrictions, libart can't directly ask the linker (which is where debuggerd lies), so we provide a proxy function in libc. Test: Build the platform, run sanitizer-status and various test apps with recoverable gwp-asan. Assert that it doesn't crash, and we get a debuggerd report. Bug: 247012630 Change-Id: I86d5e27a9ca5531c8942e62647fd377c3cd36dfd
73 lines
3 KiB
C++
73 lines
3 KiB
C++
/*
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* Copyright (C) 2019 The Android Open Source Project
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include "linker_debuggerd.h"
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#include "debuggerd/handler.h"
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#include "private/bionic_globals.h"
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#include "linker_gdb_support.h"
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#if defined(__ANDROID_APEX__)
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static debugger_process_info get_process_info() {
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return {
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.abort_msg = __libc_shared_globals()->abort_msg,
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.fdsan_table = &__libc_shared_globals()->fd_table,
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.gwp_asan_state = __libc_shared_globals()->gwp_asan_state,
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.gwp_asan_metadata = __libc_shared_globals()->gwp_asan_metadata,
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.scudo_stack_depot = __libc_shared_globals()->scudo_stack_depot,
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.scudo_region_info = __libc_shared_globals()->scudo_region_info,
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.scudo_ring_buffer = __libc_shared_globals()->scudo_ring_buffer,
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.scudo_ring_buffer_size = __libc_shared_globals()->scudo_ring_buffer_size,
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};
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}
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static gwp_asan_callbacks_t get_gwp_asan_callbacks() {
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return {
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.debuggerd_needs_gwp_asan_recovery =
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__libc_shared_globals()->debuggerd_needs_gwp_asan_recovery,
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.debuggerd_gwp_asan_pre_crash_report =
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__libc_shared_globals()->debuggerd_gwp_asan_pre_crash_report,
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.debuggerd_gwp_asan_post_crash_report =
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__libc_shared_globals()->debuggerd_gwp_asan_post_crash_report,
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};
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}
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#endif
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void linker_debuggerd_init() {
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// There may be a version mismatch between the bootstrap linker and the crash_dump in the APEX,
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// so don't pass in any process info from the bootstrap linker.
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debuggerd_callbacks_t callbacks = {
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#if defined(__ANDROID_APEX__)
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.get_process_info = get_process_info,
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.get_gwp_asan_callbacks = get_gwp_asan_callbacks,
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#endif
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.post_dump = notify_gdb_of_libraries,
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};
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debuggerd_init(&callbacks);
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}
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