10b57cec5SDimitry Andric//===-- options.inc ---------------------------------------------*- C++ -*-===// 20b57cec5SDimitry Andric// 30b57cec5SDimitry Andric// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 40b57cec5SDimitry Andric// See https://llvm.org/LICENSE.txt for license information. 50b57cec5SDimitry Andric// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 60b57cec5SDimitry Andric// 70b57cec5SDimitry Andric//===----------------------------------------------------------------------===// 80b57cec5SDimitry Andric 90b57cec5SDimitry Andric#ifndef GWP_ASAN_OPTION 100b57cec5SDimitry Andric#error "Define GWP_ASAN_OPTION prior to including this file!" 110b57cec5SDimitry Andric#endif 120b57cec5SDimitry Andric 13e8d8bef9SDimitry Andric#ifndef GWP_ASAN_DEFAULT_ENABLED 14e8d8bef9SDimitry Andric#define GWP_ASAN_DEFAULT_ENABLED true 15e8d8bef9SDimitry Andric#endif 16e8d8bef9SDimitry Andric 17e8d8bef9SDimitry Andric#ifndef GWP_ASAN_STRINGIFY 18e8d8bef9SDimitry Andric#define GWP_ASAN_STRINGIFY(S) GWP_ASAN_STRINGIFY_(S) 19e8d8bef9SDimitry Andric#define GWP_ASAN_STRINGIFY_(S) #S 20e8d8bef9SDimitry Andric#endif 21e8d8bef9SDimitry Andric 22e8d8bef9SDimitry AndricGWP_ASAN_OPTION(bool, Enabled, GWP_ASAN_DEFAULT_ENABLED, 23e8d8bef9SDimitry Andric "Is GWP-ASan enabled? Defaults to " GWP_ASAN_STRINGIFY( 24e8d8bef9SDimitry Andric GWP_ASAN_DEFAULT_ENABLED) ".") 250b57cec5SDimitry Andric 2668d75effSDimitry AndricGWP_ASAN_OPTION(int, MaxSimultaneousAllocations, 16, 2768d75effSDimitry Andric "Number of simultaneously-guarded allocations available in the " 2868d75effSDimitry Andric "pool. Defaults to 16.") 290b57cec5SDimitry Andric 300b57cec5SDimitry AndricGWP_ASAN_OPTION(int, SampleRate, 5000, 310b57cec5SDimitry Andric "The probability (1 / SampleRate) that an allocation is " 320b57cec5SDimitry Andric "selected for GWP-ASan sampling. Default is 5000. Sample rates " 33e8d8bef9SDimitry Andric "up to (2^30 - 1) are supported.") 340b57cec5SDimitry Andric 355ffd83dbSDimitry Andric// Developer note - This option is not actually processed by GWP-ASan itself. It 365ffd83dbSDimitry Andric// is included here so that a user can specify whether they want signal handlers 375ffd83dbSDimitry Andric// or not. The supporting allocator should inspect this value to see whether 385ffd83dbSDimitry Andric// signal handlers need to be installed, and then use 395ffd83dbSDimitry Andric// crash_handler::installSignalHandlers() in order to install the handlers. Note 405ffd83dbSDimitry Andric// that in order to support signal handlers, you will need to link against the 415ffd83dbSDimitry Andric// optional crash_handler component. 420b57cec5SDimitry AndricGWP_ASAN_OPTION( 430b57cec5SDimitry Andric bool, InstallSignalHandlers, true, 440b57cec5SDimitry Andric "Install GWP-ASan signal handlers for SIGSEGV during dynamic loading. This " 450b57cec5SDimitry Andric "allows better error reports by providing stack traces for allocation and " 460b57cec5SDimitry Andric "deallocation when reporting a memory error. GWP-ASan's signal handler " 470b57cec5SDimitry Andric "will forward the signal to any previously-installed handler, and user " 480b57cec5SDimitry Andric "programs that install further signal handlers should make sure they do " 490b57cec5SDimitry Andric "the same. Note, if the previously installed SIGSEGV handler is SIG_IGN, " 500b57cec5SDimitry Andric "we terminate the process after dumping the error report.") 515ffd83dbSDimitry Andric 52*bdd1243dSDimitry AndricGWP_ASAN_OPTION( 53*bdd1243dSDimitry Andric bool, Recoverable, false, 54*bdd1243dSDimitry Andric "Install GWP-ASan's signal handler in recoverable mode. This means that " 55*bdd1243dSDimitry Andric "upon GWP-ASan detecting an error, it'll print the error report, but *not* " 56*bdd1243dSDimitry Andric "crash. Only one crash per sampled allocation will ever be recorded, and " 57*bdd1243dSDimitry Andric "if a sampled allocation does actually cause a crash, it'll permanently " 58*bdd1243dSDimitry Andric "occupy a slot in the pool. The recoverable mode also means that " 59*bdd1243dSDimitry Andric "previously-installed signal handlers will only be triggered for " 60*bdd1243dSDimitry Andric "non-GWP-ASan errors, as all GWP-ASan errors won't be forwarded.") 61*bdd1243dSDimitry Andric 625ffd83dbSDimitry AndricGWP_ASAN_OPTION(bool, InstallForkHandlers, true, 635ffd83dbSDimitry Andric "Install GWP-ASan atfork handlers to acquire internal locks " 645ffd83dbSDimitry Andric "before fork and release them after.") 65e8d8bef9SDimitry Andric 66e8d8bef9SDimitry AndricGWP_ASAN_OPTION(bool, help, false, "Print a summary of the available options.") 67e8d8bef9SDimitry Andric 68e8d8bef9SDimitry Andric// ============================================================================= 69e8d8bef9SDimitry Andric// ==== WARNING 70e8d8bef9SDimitry Andric// ============================================================================= 71e8d8bef9SDimitry Andric// If you are adding flags to GWP-ASan, please note that GWP-ASan flag strings 72e8d8bef9SDimitry Andric// may be parsed by trusted system components (on Android, GWP-ASan flag strings 73e8d8bef9SDimitry Andric// are parsed by libc during the dynamic loader). This means that GWP-ASan 74e8d8bef9SDimitry Andric// should never feature flags like log paths on disk, because this can lead to 75e8d8bef9SDimitry Andric// arbitrary file write and thus privilege escalation. For an example, see the 76e8d8bef9SDimitry Andric// setuid ASan log_path exploits: https://www.exploit-db.com/exploits/46241. 77e8d8bef9SDimitry Andric// 78e8d8bef9SDimitry Andric// Please place all new flags above this warning, so that the warning always 79e8d8bef9SDimitry Andric// stays at the bottom. 80