From 4b23c24bc8ec84ab443df42c9fdfc74de964febb Mon Sep 17 00:00:00 2001
From: Jake Ehrlich <jakehehrlich@google.com>
Date: Tue, 17 Sep 2019 00:34:41 +0000
Subject: [libFuzzer] Always print DSO map on Fuchsia libFuzzer launch

Fuchsia doesn't have /proc/id/maps, so it relies on the kernel logging system
to provide the DSO map to be able to symbolize in the context of ASLR. The DSO
map is logged automatically on Fuchsia when encountering a crash or writing to
the sanitizer log for the first time in a process. There are several cases
where libFuzzer doesn't encounter a crash, e.g. on timeouts, OOMs, and when
configured to print new PCs as they become covered, to name a few. Therefore,
this change always writes to the sanitizer log on startup to ensure the DSO map
is available in the log.

Author: aarongreen
Differential Revision: https://reviews.llvm.org/D66233

llvm-svn: 372056
---
 compiler-rt/lib/fuzzer/FuzzerExtFunctions.def | 1 +
 1 file changed, 1 insertion(+)

(limited to 'compiler-rt/lib/fuzzer/FuzzerExtFunctions.def')

diff --git a/compiler-rt/lib/fuzzer/FuzzerExtFunctions.def b/compiler-rt/lib/fuzzer/FuzzerExtFunctions.def
index 7b53b085560..51edf8444e9 100644
--- a/compiler-rt/lib/fuzzer/FuzzerExtFunctions.def
+++ b/compiler-rt/lib/fuzzer/FuzzerExtFunctions.def
@@ -33,6 +33,7 @@ EXT_FUNC(__sanitizer_install_malloc_and_free_hooks, int,
          (void (*malloc_hook)(const volatile void *, size_t),
           void (*free_hook)(const volatile void *)),
          false);
+EXT_FUNC(__sanitizer_log_write, void, (const char *buf, size_t len), false);
 EXT_FUNC(__sanitizer_purge_allocator, void, (), false);
 EXT_FUNC(__sanitizer_print_memory_profile, void, (size_t, size_t), false);
 EXT_FUNC(__sanitizer_print_stack_trace, void, (), true);
-- 
cgit v1.2.3

