Add sigaction and ucontext support to Mac crashlog

config.lib

@@ -1908,6 +1908,31 @@ EOL
 				fi
 			fi
 		fi
+
+		log 2 "executing $cc_host $CFLAGS $CFLAGS_ENV $LDFLAGS $LDFLAGS_ENV $STATIC_FLAGS -o tmp.config.ucontext -x c++ - -ldl"
+		"$cc_host" $CFLAGS $CFLAGS_ENV $LDFLAGS $LDFLAGS_ENV $STATIC_FLAGS -o tmp.config.ucontext -x c++ - -ldl 2> /dev/null << EOL
+			#include <sys/ucontext.h>
+			int main() {
+				ucontext_t context;
+#if defined(__x86_64__)
+				void *ptr = (void *) context.uc_mcontext->__ss.__rip;
+#elif defined(__i386)
+				void *ptr = (void *) context.uc_mcontext->__ss.__rip;
+#else
+#error Unknown arch
+#endif
+				return 0;
+			}
+EOL
+		ret=$?
+		rm -f tmp.config.ucontext
+		log 2 "  exit code $ret"
+		if [ $ret -ne 0 ]; then
+			log 1 "checking ucontext... no"
+		else
+			log 1 "checking ucontext... found"
+			CFLAGS="$CFLAGS -DWITH_UCONTEXT"
+		fi
 	fi
 
 	if [ "$os" = "HAIKU" ]; then

src/os/macosx/crashlog_osx.cpp

@@ -22,6 +22,9 @@
 #include <mach-o/arch.h>
 #include <dlfcn.h>
 #include <cxxabi.h>
+#ifdef WITH_UCONTEXT
+#include <sys/ucontext.h>
+#endif
 
 #include "../../safeguards.h"
 
@@ -104,6 +107,10 @@ static bool ExecReadStdout(const char *file, char *const *args, char *&buffer, c
 class CrashLogOSX : public CrashLog {
 	/** Signal that has been thrown. */
 	int signum;
+	siginfo_t *si;
+	void *context;
+	bool signal_instruction_ptr_valid;
+	void *signal_instruction_ptr;
 
 	char filename_log[MAX_PATH];        ///< Path of crash.log
 	char filename_save[MAX_PATH];       ///< Path of crash.sav
@@ -130,14 +137,32 @@ class CrashLogOSX : public CrashLog {
 
 	char *LogError(char *buffer, const char *last, const char *message) const override
 	{
-		return buffer + seprintf(buffer, last,
+		buffer += seprintf(buffer, last,
 				"Crash reason:\n"
-				" Signal:  %s (%d)\n"
+				" Signal:  %s (%d)\n",
-				" Message: %s\n\n",
 				strsignal(this->signum),
-				this->signum,
+				this->signum
-				message == NULL ? "<none>" : message
 		);
+		if (this->si) {
+			buffer += seprintf(buffer, last,
+					"          si_code: %d\n",
+					this->si->si_code);
+			if (this->signum != SIGABRT) {
+				buffer += seprintf(buffer, last,
+						"          Fault address: %p\n",
+						this->si->si_addr);
+				if (this->signal_instruction_ptr_valid) {
+					buffer += seprintf(buffer, last,
+							"          Instruction address: %p\n",
+							this->signal_instruction_ptr);
+				}
+			}
+		}
+		buffer += seprintf(buffer, last,
+				" Message: %s\n\n",
+				message == nullptr ? "<none>" : message
+		);
+		return buffer;
 	}
 
 	char *LogStacktrace(char *buffer, const char *last) const override
@@ -226,6 +251,7 @@ class CrashLogOSX : public CrashLog {
 		buffer += seprintf(buffer, last, "LLDB info:\n");
 
 		char pid_buffer[16];
+		char disasm_buffer[64];
 
 		seprintf(pid_buffer, lastof(pid_buffer), "%d", pid);
 
@@ -239,6 +265,12 @@ class CrashLogOSX : public CrashLog {
 		args.push_back("-o");
 		args.push_back(IsNonMainThread() ? "bt all" : "bt");
 
+		if (this->GetMessage() == nullptr && this->signal_instruction_ptr_valid) {
+			seprintf(disasm_buffer, lastof(disasm_buffer), "disassemble -b -F intel -c 1 -s %p", this->signal_instruction_ptr);
+			args.push_back("-o");
+			args.push_back(disasm_buffer);
+		}
+
 		args.push_back(nullptr);
 		if (!ExecReadStdout("lldb", const_cast<char* const*>(&(args[0])), buffer, last)) {
 			buffer = buffer_orig;
@@ -255,6 +287,57 @@ class CrashLogOSX : public CrashLog {
 	{
 		buffer = LogLldbInfo(buffer, last);
 
+#ifdef WITH_UCONTEXT
+		ucontext_t *ucontext = static_cast<ucontext_t *>(context);
+#if defined(__x86_64__)
+		const auto &gregs = ucontext->uc_mcontext->__ss;
+		buffer += seprintf(buffer, last,
+			"Registers:\n"
+			" rax: %#16llx rbx: %#16llx rcx: %#16llx rdx: %#16llx\n"
+			" rsi: %#16llx rdi: %#16llx rbp: %#16llx rsp: %#16llx\n"
+			" r8:  %#16llx r9:  %#16llx r10: %#16llx r11: %#16llx\n"
+			" r12: %#16llx r13: %#16llx r14: %#16llx r15: %#16llx\n"
+			" rip: %#16llx rflags: %#8llx\n\n",
+			gregs.__rax,
+			gregs.__rbx,
+			gregs.__rcx,
+			gregs.__rdx,
+			gregs.__rsi,
+			gregs.__rdi,
+			gregs.__rbp,
+			gregs.__rsp,
+			gregs.__r8,
+			gregs.__r9,
+			gregs.__r10,
+			gregs.__r11,
+			gregs.__r12,
+			gregs.__r13,
+			gregs.__r14,
+			gregs.__r15,
+			gregs.__rip,
+			gregs.__rflags
+		);
+#elif defined(__i386)
+		const auto &gregs = ucontext->uc_mcontext->__ss;
+		buffer += seprintf(buffer, last,
+			"Registers:\n"
+			" eax: %#8x ebx: %#8x ecx: %#8x edx: %#8x\n"
+			" esi: %#8x edi: %#8x ebp: %#8x esp: %#8x\n"
+			" eip: %#8x eflags: %#8x\n\n",
+			gregs.__eax,
+			gregs.__ebx,
+			gregs.__ecx,
+			gregs.__edx,
+			gregs.__esi,
+			gregs.__edi,
+			gregs.__ebp,
+			gregs.__esp,
+			gregs.__eip,
+			gregs.__eflags
+		);
+#endif
+#endif
+
 		return buffer;
 	}
 
@@ -263,11 +346,24 @@ public:
 	 * A crash log is always generated by signal.
 	 * @param signum the signal that was caused by the crash.
 	 */
-	CrashLogOSX(int signum) : signum(signum)
+	CrashLogOSX(int signum, siginfo_t *si, void *context) : signum(signum), si(si), context(context)
 	{
 		filename_log[0] = '\0';
 		filename_save[0] = '\0';
 		filename_screenshot[0] = '\0';
+
+		this->signal_instruction_ptr_valid = false;
+
+#ifdef WITH_UCONTEXT
+		ucontext_t *ucontext = static_cast<ucontext_t *>(context);
+#if defined(__x86_64__)
+		this->signal_instruction_ptr = (void *) ucontext->uc_mcontext->__ss.__rip;
+		this->signal_instruction_ptr_valid = true;
+#elif defined(__i386)
+		this->signal_instruction_ptr = (void *) ucontext->uc_mcontext->__ss.__eip;
+		this->signal_instruction_ptr_valid = true;
+#endif
+#endif /* WITH_UCONTEXT */
 	}
 
 	/** Generate the crash log. */
@@ -327,7 +423,7 @@ static const int _signals_to_handle[] = { SIGSEGV, SIGABRT, SIGFPE, SIGBUS, SIGI
  * @note Not static so it shows up in the backtrace.
  * @param signum the signal that caused us to crash.
  */
-void CDECL HandleCrash(int signum)
+void CDECL HandleCrash(int signum, siginfo_t *si, void *context)
 {
 	/* Disable all handling of signals by us, so we don't go into infinite loops. */
 	for (const int *i = _signals_to_handle; i != endof(_signals_to_handle); i++) {
@@ -342,7 +438,7 @@ void CDECL HandleCrash(int signum)
 		abort();
 	}
 
-	CrashLogOSX log(signum);
+	CrashLogOSX log(signum, si, context);
 	log.MakeCrashLog();
 	log.DisplayCrashDialog();
 
@@ -353,6 +449,11 @@ void CDECL HandleCrash(int signum)
 /* static */ void CrashLog::InitialiseCrashLog()
 {
 	for (const int *i = _signals_to_handle; i != endof(_signals_to_handle); i++) {
-		signal(*i, HandleCrash);
+		struct sigaction sa;
+		memset(&sa, 0, sizeof(sa));
+		sa.sa_flags = SA_SIGINFO | SA_RESTART;
+		sigemptyset(&sa.sa_mask);
+		sa.sa_sigaction = HandleCrash;
+		sigaction(*i, &sa, nullptr);
 	}
 }