commit 35ce3fa32bbe38bc87523fedea94c025aeb73dbd
author Josh Gao <jmgao@google.com> Tue Aug 23 11:09:06 2016 -0700
committer Josh Gao <jmgao@google.com> Tue Aug 23 12:31:14 2016 -0700
tree 03e8d57368156f333b854577bc888fb41de89ab4
parent 21c25e39a0ceb843c66dc8ac969f6ba6329fb89c

debuggerd: don't display fault addr for manually sent signals.

Bug: http://b/30819045
Change-Id: Ic8ab21298dcba6acdfa876e7c729b14b0bf2afbb
Test: `killall -TRAP surfaceflinger` no longer shows fault addr,
      crasher still does

debuggerd/tombstone.cpp

diff --git a/debuggerd/tombstone.cpp b/debuggerd/tombstone.cpp
index 9359678..a56f34d 100644
--- a/debuggerd/tombstone.cpp
+++ b/debuggerd/tombstone.cpp
@@ -56,8 +56,13 @@
 #define TOMBSTONE_DIR   "/data/tombstones"
 #define TOMBSTONE_TEMPLATE (TOMBSTONE_DIR"/tombstone_%02d")
 
-static bool signal_has_si_addr(int sig) {
-  switch (sig) {
+static bool signal_has_si_addr(int si_signo, int si_code) {
+  // Manually sent signals won't have si_addr.
+  if (si_code == SI_USER || si_code == SI_QUEUE || si_code == SI_TKILL) {
+    return false;
+  }
+
+  switch (si_signo) {
     case SIGBUS:
     case SIGFPE:
     case SIGILL:
@@ -185,7 +190,7 @@
   }
 
   char addr_desc[32]; // ", fault addr 0x1234"
-  if (signal_has_si_addr(si.si_signo)) {
+  if (signal_has_si_addr(si.si_signo, si.si_code)) {
     snprintf(addr_desc, sizeof(addr_desc), "%p", si.si_addr);
   } else {
     snprintf(addr_desc, sizeof(addr_desc), "--------");
@@ -359,7 +364,7 @@
   siginfo_t si;
   memset(&si, 0, sizeof(si));
   if (ptrace(PTRACE_GETSIGINFO, tid, 0, &si) != -1) {
-    print_fault_address_marker = signal_has_si_addr(si.si_signo);
+    print_fault_address_marker = signal_has_si_addr(si.si_signo, si.si_code);
     addr = reinterpret_cast<uintptr_t>(si.si_addr);
   } else {
     ALOGE("Cannot get siginfo for %d: %s\n", tid, strerror(errno));