diff --git a/linker/debugger.c b/linker/debugger.c
index abb383c..648dc78 100644
--- a/linker/debugger.c
+++ b/linker/debugger.c
@@ -87,13 +87,49 @@
     return s;
 }
 
-void debugger_signal_handler(int n)
+#include "linker_format.h"
+#include <../libc/private/logd.h>
+
+/*
+ * Writes a summary of the signal to the log file.
+ *
+ * We could be here as a result of native heap corruption, or while a
+ * mutex is being held, so we don't want to use any libc functions that
+ * could allocate memory or hold a lock.
+ */
+static void logSignalSummary(int signum, const siginfo_t* info)
+{
+    char buffer[128];
+
+    char* signame;
+    switch (signum) {
+        case SIGILL:    signame = "SIGILL";     break;
+        case SIGABRT:   signame = "SIGABRT";    break;
+        case SIGBUS:    signame = "SIGBUS";     break;
+        case SIGFPE:    signame = "SIGFPE";     break;
+        case SIGSEGV:   signame = "SIGSEGV";    break;
+        case SIGSTKFLT: signame = "SIGSTKFLT";  break;
+        case SIGPIPE:   signame = "SIGPIPE";    break;
+        default:        signame = "???";        break;
+    }
+
+    format_buffer(buffer, sizeof(buffer),
+        "Fatal signal %d (%s) at 0x%08x (code=%d)",
+        signum, signame, info->si_addr, info->si_code);
+
+    __libc_android_log_write(ANDROID_LOG_FATAL, "libc", buffer);
+}
+
+/*
+ * Catches fatal signals so we can ask debuggerd to ptrace us before
+ * we crash.
+ */
+void debugger_signal_handler(int n, siginfo_t* info, void* unused)
 {
     unsigned tid;
     int s;
 
-    /* avoid picking up GC interrupts */
-    signal(SIGUSR1, SIG_IGN);
+    logSignalSummary(n, info);
 
     tid = gettid();
     s = socket_abstract_client("android:debuggerd", SOCK_STREAM);
@@ -117,16 +153,22 @@
     }
 
     /* remove our net so we fault for real when we return */
-    signal(n, SIG_IGN);
+    signal(n, SIG_DFL);
 }
 
 void debugger_init()
 {
-    signal(SIGILL, debugger_signal_handler);
-    signal(SIGABRT, debugger_signal_handler);
-    signal(SIGBUS, debugger_signal_handler);
-    signal(SIGFPE, debugger_signal_handler);
-    signal(SIGSEGV, debugger_signal_handler);
-    signal(SIGSTKFLT, debugger_signal_handler);
-    signal(SIGPIPE, debugger_signal_handler);
+    struct sigaction act;
+    memset(&act, 0, sizeof(act));
+    act.sa_sigaction = debugger_signal_handler;
+    act.sa_flags = SA_RESTART | SA_SIGINFO;
+    sigemptyset(&act.sa_mask);
+
+    sigaction(SIGILL, &act, NULL);
+    sigaction(SIGABRT, &act, NULL);
+    sigaction(SIGBUS, &act, NULL);
+    sigaction(SIGFPE, &act, NULL);
+    sigaction(SIGSEGV, &act, NULL);
+    sigaction(SIGSTKFLT, &act, NULL);
+    sigaction(SIGPIPE, &act, NULL);
 }