[Xposed General] romracer:
Well, "fatal signal" in Linux/Android terms means the process died or crashed. The "F/libc" means the fatal crash occurred in the libc library.

I also get these errors on my Moto X. I suspect it has something to do with us using Android 5.0 since most other Lollipop phones are on 5.0.1 or 5.0.2. My log contains a bit more information, notably the backtrace, which indicates this is occurring in dex2oat (one of the files replaced by Xposed).

11-20 00:00:01.980 I/Xposed ( 385): -----------------
11-20 00:00:01.980 I/Xposed ( 385): Starting Xposed binary version 60, compiled for SDK 21
11-20 00:00:01.980 I/Xposed ( 385): Phone: XT1095 (motorola), Android version 5.0 (SDK 21)
11-20 00:00:01.980 I/Xposed ( 385): ROM: LXE22.46-11
11-20 00:00:01.980 I/Xposed ( 385): Build fingerprint: motorola/victara_tmo/victara:5.0/LXE22.46-11/10:user/release-keys
11-20 00:00:01.980 I/Xposed ( 385): Platform: armeabi-v7a, 32-bit binary, system server: yes
11-20 00:00:01.980 I/Xposed ( 385): SELinux enabled: yes, enforcing: yes
02-14 12:04:48.293 I/Xposed ( 385): -----------------
02-14 12:04:48.298 I/Xposed ( 385): Added Xposed (/system/framework/XposedBridge.jar) to CLASSPATH
02-14 12:04:48.709 I/Xposed ( 385): Detected ART runtime
02-14 12:04:48.735 I/Xposed ( 385): Found Xposed class de/robv/android/xposed/XposedBridge, now initializing
02-14 12:04:48.919 I/Xposed ( 385): Initializing XposedBridge version 61
02-14 12:04:49.038 I/Xposed ( 385): Loading modules from /data/app/com.oasisfeng.greenify-2/base.apk
02-14 12:04:49.237 I/Xposed ( 385): Loading class com.oasisfeng.greenify.pro.FrameworkPatch
02-14 12:04:49.261 I/Xposed ( 385): Loading class com.oasisfeng.greenify.pro.SettingsPatch
02-14 23:02:35.698 F/libc (12653): Fatal signal 11 (SIGSEGV), code 2, fault addr 0xb32050c0 in tid 12653 (main)
02-14 23:02:35.698 F/libc (12653): Fatal signal 11 (SIGSEGV), code 2, fault addr 0xb3221eae in tid 12657 (Compiler driver)
02-14 23:02:35.698 F/libc (12653): Fatal signal 11 (SIGSEGV), code 2, fault addr 0xb3221f1a in tid 12656 (Compiler driver)
02-14 23:02:35.698 F/libc (12653): Fatal signal 11 (SIGSEGV), code 2, fault addr 0xb322212a in tid 12655 (Compiler driver)
02-14 23:02:35.841 I/DEBUG ( 368): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
02-14 23:02:35.841 I/DEBUG ( 368): Build fingerprint: 'motorola/victara_tmo/victara:5.0/LXE22.46-11/10:user/release-keys'
02-14 23:02:35.842 I/DEBUG ( 368): Revision: 'p2bf'
02-14 23:02:35.842 I/DEBUG ( 368): ABI: 'arm'
02-14 23:02:35.846 I/DEBUG ( 368): pid: 12653, tid: 12657, name: Compiler driver >>> /system/bin/dex2oat <<<
02-14 23:02:35.846 I/DEBUG ( 368): signal 11 (SIGSEGV), code 2 (SEGV_ACCERR), fault addr 0xb3221eae
02-14 23:02:35.893 I/DEBUG ( 368): r0 00000001 r1 0000206e r2 0000000b r3 00000002
02-14 23:02:35.893 E/DEBUG ( 368): AM write failure (32 / Broken pipe)
02-14 23:02:35.893 I/DEBUG ( 368): r4 b3221eac r5 00000002 r6 b2ec0b30 r7 00000007
02-14 23:02:35.893 I/DEBUG ( 368): r8 00000435 r9 b6ea8618 sl b6a4a970 fp b3221ea8
02-14 23:02:35.893 I/DEBUG ( 368): ip b6a1c538 sp b2ec0a58 lr b6985e2f pc b696753a cpsr 600b0030
02-14 23:02:35.893 I/DEBUG ( 368):
02-14 23:02:35.893 I/DEBUG ( 368): backtrace:
02-14 23:02:35.893 I/DEBUG ( 368): #00 pc 0012253a /system/lib/libart-compiler.so (art::optimizer::DexCompiler::Compile()+517)
02-14 23:02:35.893 I/DEBUG ( 368): #01 pc 001230cf /system/lib/libart-compiler.so (ArtCompileDEX+114)
02-14 23:02:35.893 I/DEBUG ( 368): #02 pc 001434cd /system/lib/libart-compiler.so (art::CompilerDriver::CompileMethod(art::DexFile::CodeItem const*, unsigned int, art::InvokeType, unsigned short, unsigned int, _jobject*, art::DexFile const&, art::DexToDexCompilationLevel)+704)
02-14 23:02:35.893 I/DEBUG ( 368): #03 pc 00143d5b /system/lib/libart-compiler.so (art::CompilerDriver::CompileClass(art::ParallelCompilationManager const*, unsigned int)+1458)
02-14 23:02:35.894 I/DEBUG ( 368): #04 pc 0013aac1 /system/lib/libart-compiler.so
02-14 23:02:35.894 I/DEBUG ( 368): #05 pc 0022d6cb /system/lib/libart.so (art::ThreadPoolWorker::Run()+34)
02-14 23:02:35.894 I/DEBUG ( 368): #06 pc 0022df19 /system/lib/libart.so (art::ThreadPoolWorker::Callback(void*)+52)
02-14 23:02:35.894 I/DEBUG ( 368): #07 pc 00015e6b /system/lib/libc.so (__pthread_start(void*)+30)
02-14 23:02:35.894 I/DEBUG ( 368): #08 pc 00013e3f /system/lib/libc.so (__start_thread+6)
02-14 23:02:36.000 I/DEBUG ( 368):
02-14 23:02:36.000 I/DEBUG ( 368): Tombstone written to: /data/tombstones/tombstone_09
02-14 23:02:36.051 E/DEBUG ( 368): unexpected waitpid response: n=12656, status=0000000b
02-14 23:03:07.209 F/libc (12713): Fatal signal 11 (SIGSEGV), code 2, fault addr 0xb327d0c0 in tid 12713 (main)
02-14 23:03:07.209 F/libc (12713): Fatal signal 11 (SIGSEGV), code 2, fault addr 0xb3299eae in tid 12715 (Compiler driver)
02-14 23:03:07.209 F/libc (12713): Fatal signal 11 (SIGSEGV), code 2, fault addr 0xb3299f1a in tid 12716 (Compiler driver)
02-14 23:03:07.209 F/libc (12713): Fatal signal 11 (SIGSEGV), code 2, fault addr 0xb329a12a in tid 12717 (Compiler driver)
02-14 23:03:07.340 I/DEBUG (12665): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
02-14 23:03:07.340 E/DEBUG (12665): AM write failure (32 / Broken pipe)
02-14 23:03:07.340 I/DEBUG (12665): Build fingerprint: 'motorola/victara_tmo/victara:5.0/LXE22.46-11/10:user/release-keys'
02-14 23:03:07.340 I/DEBUG (12665): Revision: 'p2bf'
02-14 23:03:07.340 I/DEBUG (12665): ABI: 'arm'
02-14 23:03:07.340 I/DEBUG (12665): pid: 12713, tid: 12713, name: main >>> /system/bin/dex2oat <<<
02-14 23:03:07.340 I/DEBUG (12665): signal 11 (SIGSEGV), code 2 (SEGV_ACCERR), fault addr 0xb327d0c0
02-14 23:03:07.356 I/DEBUG (12665): r0 00000001 r1 0000106e r2 00000028 r3 00000002
02-14 23:03:07.356 I/DEBUG (12665): r4 b327d0be r5 00000003 r6 beb60e08 r7 0000013c
02-14 23:03:07.356 I/DEBUG (12665): r8 00008367 r9 b6f20618 sl b6ac2970 fp b327d0b8
02-14 23:03:07.356 I/DEBUG (12665): ip b6a94538 sp beb60d30 lr b69fde2f pc b69df53a cpsr 600e0030
02-14 23:03:07.356 I/DEBUG (12665):
02-14 23:03:07.356 I/DEBUG (12665): backtrace:
02-14 23:03:07.356 I/DEBUG (12665): #00 pc 0012253a /system/lib/libart-compiler.so (art::optimizer::DexCompiler::Compile()+517)
02-14 23:03:07.356 I/DEBUG (12665): #01 pc 001230cf /system/lib/libart-compiler.so (ArtCompileDEX+114)
02-14 23:03:07.357 I/DEBUG (12665): #02 pc 001434cd /system/lib/libart-compiler.so (art::CompilerDriver::CompileMethod(art::DexFile::CodeItem const*, unsigned int, art::InvokeType, unsigned short, unsigned int, _jobject*, art::DexFile const&, art::DexToDexCompilationLevel)+704)
02-14 23:03:07.357 I/DEBUG (12665): #03 pc 00143d5b /system/lib/libart-compiler.so (art::CompilerDriver::CompileClass(art::ParallelCompilationManager const*, unsigned int)+1458)
02-14 23:03:07.357 I/DEBUG (12665): #04 pc 0013aac1 /system/lib/libart-compiler.so
02-14 23:03:07.357 I/DEBUG (12665): #05 pc 0022d9b1 /system/lib/libart.so (art::ThreadPool::Wait(art::Thread*, bool, bool)+172)
02-14 23:03:07.357 I/DEBUG (12665): #06 pc 0013da47 /system/lib/libart-compiler.so
02-14 23:03:07.357 I/DEBUG (12665): #07 pc 0013e2bb /system/lib/libart-compiler.so (art::CompilerDriver::Compile(_jobject*, std::__1::vector<art::DexFile const*, std::__1::allocator<art::DexFile const*> > const&, art::ThreadPool*, art::TimingLogger*)+146)
02-14 23:03:07.357 I/DEBUG (12665): #08 pc 00146a75 /system/lib/libart-compiler.so (art::CompilerDriver::CompileAll(_jobject*, std::__1::vector<art::DexFile const*, std::__1::allocator<art::DexFile const*> > const&, art::TimingLogger*)+64)
02-14 23:03:07.357 I/DEBUG (12665): #09 pc 0000c7c9 /system/bin/dex2oat
02-14 23:03:07.357 I/DEBUG (12665): #10 pc 0000ea3f /system/bin/dex2oat
02-14 23:03:07.357 I/DEBUG (12665): #11 pc 00012115 /system/lib/libc.so (__libc_init+44)
02-14 23:03:07.357 I/DEBUG (12665): #12 pc 00006844 /system/bin/dex2oat
02-14 23:03:07.497 I/DEBUG (12665):
02-14 23:03:07.497 I/DEBUG (12665): Tombstone written to: /data/tombstones/tombstone_00
02-14 23:03:07.548 E/DEBUG (12665): unexpected waitpid response: n=12716, status=0000000b