strace: Print detailed signal information

- Add support for retrieving the `siginfo_t` structure of a signal
event from the Debugger API.
- Add code to `strace` to display this information every time a
signal event occurs, similar to the Linux `strace` tool.

Change-Id: If4e92bbae049ee0b52efaf9fc911d66511da62f4
Reviewed-on: https://review.haiku-os.org/c/haiku/+/6393
Tested-by: Commit checker robot <[email protected]>
Reviewed-by: waddlesplash <[email protected]>

headers/os/kernel/debugger.h

@@ -533,6 +533,7 @@ typedef struct {
 	debug_origin		origin;
 	int					signal;		// the signal
 	struct sigaction	handler;	// the signal handler
+	siginfo_t			info;		// the signal info
 	bool				deadly;		// true, if handling the signal will kill
 									// the team
 } debug_signal_received;

headers/private/kernel/user_debugger.h

@@ -255,7 +255,7 @@ void user_debug_post_syscall(uint32 syscall, void *args, uint64 returnValue,
 		bigtime_t startTime);
 bool user_debug_exception_occurred(debug_exception_type exception, int signal);
 bool user_debug_handle_signal(int signal, struct sigaction *handler,
-		bool deadly);
+		siginfo_t *info, bool deadly);
 void user_debug_stop_thread();
 void user_debug_team_created(team_id teamID);
 void user_debug_team_deleted(team_id teamID, port_id debuggerPort);

src/bin/debug/strace/Jamfile

@@ -24,6 +24,7 @@ local straceSources =
 	fcntl.cpp
 	ioctl.cpp
 	network.cpp
+	signals.cpp
 ;
 
 # Our compiler badly chokes when compiling the generated file. So will

src/bin/debug/strace/signals.cpp

@@ -0,0 +1,201 @@
+/*
+ * Copyright 2023, Trung Nguyen, [email protected].
+ * Distributed under the terms of the MIT License.
+ */
+
+
+#include <stdio.h>
+
+#include <string>
+
+#include "signals.h"
+
+
+// signal names
+static const char *kSignalName[] = {
+	/*  0 */ "SIG0",
+	/*  1 */ "SIGHUP",
+	/*  2 */ "SIGINT",
+	/*  3 */ "SIGQUIT",
+	/*  4 */ "SIGILL",
+	/*  5 */ "SIGCHLD",
+	/*  6 */ "SIGABRT",
+	/*  7 */ "SIGPIPE",
+	/*  8 */ "SIGFPE",
+	/*  9 */ "SIGKILL",
+	/* 10 */ "SIGSTOP",
+	/* 11 */ "SIGSEGV",
+	/* 12 */ "SIGCONT",
+	/* 13 */ "SIGTSTP",
+	/* 14 */ "SIGALRM",
+	/* 15 */ "SIGTERM",
+	/* 16 */ "SIGTTIN",
+	/* 17 */ "SIGTTOU",
+	/* 18 */ "SIGUSR1",
+	/* 19 */ "SIGUSR2",
+	/* 20 */ "SIGWINCH",
+	/* 21 */ "SIGKILLTHR",
+	/* 22 */ "SIGTRAP",
+	/* 23 */ "SIGPOLL",
+	/* 24 */ "SIGPROF",
+	/* 25 */ "SIGSYS",
+	/* 26 */ "SIGURG",
+	/* 27 */ "SIGVTALRM",
+	/* 28 */ "SIGXCPU",
+	/* 29 */ "SIGXFSZ",
+	/* 30 */ "SIGBUS",
+	/* 31 */ "SIGRESERVED1",
+	/* 32 */ "SIGRESERVED2",
+};
+
+
+std::string
+signal_name(int signal)
+{
+	if (signal >= 0 && signal <= SIGRESERVED2)
+		return kSignalName[signal];
+
+	static char buffer[32];
+	sprintf(buffer, "%d", signal);
+	return buffer;
+}
+
+
+static const char *
+signal_code(int signal, int code)
+{
+#define CASE(X) case X: return #X;
+	switch (code) {
+		CASE(SI_USER)
+		CASE(SI_QUEUE)
+		CASE(SI_TIMER)
+		CASE(SI_ASYNCIO)
+		CASE(SI_MESGQ)
+	}
+
+	switch (signal) {
+		case SIGILL:
+			switch (code) {
+				CASE(ILL_ILLOPC)
+				CASE(ILL_ILLOPN)
+				CASE(ILL_ILLADR)
+				CASE(ILL_ILLTRP)
+				CASE(ILL_PRVOPC)
+				CASE(ILL_PRVREG)
+				CASE(ILL_COPROC)
+				CASE(ILL_BADSTK)
+			}
+			break;
+		case SIGFPE:
+			switch (code) {
+				CASE(FPE_INTDIV)
+				CASE(FPE_INTOVF)
+				CASE(FPE_FLTDIV)
+				CASE(FPE_FLTOVF)
+				CASE(FPE_FLTUND)
+				CASE(FPE_FLTRES)
+				CASE(FPE_FLTINV)
+				CASE(FPE_FLTSUB)
+			}
+			break;
+		case SIGSEGV:
+			switch (code) {
+				CASE(SEGV_MAPERR)
+				CASE(SEGV_ACCERR)
+			}
+			break;
+		case SIGBUS:
+			switch (code) {
+				CASE(BUS_ADRALN)
+				CASE(BUS_ADRERR)
+				CASE(BUS_OBJERR)
+			}
+			break;
+		case SIGTRAP:
+			switch (code) {
+				CASE(TRAP_BRKPT)
+				CASE(TRAP_TRACE)
+			}
+			break;
+		case SIGCHLD:
+			switch (code) {
+				CASE(CLD_EXITED)
+				CASE(CLD_KILLED)
+				CASE(CLD_DUMPED)
+				CASE(CLD_TRAPPED)
+				CASE(CLD_STOPPED)
+				CASE(CLD_CONTINUED)
+			}
+			break;
+		case SIGPOLL:
+			switch (code) {
+				CASE(POLL_IN)
+				CASE(POLL_OUT)
+				CASE(POLL_MSG)
+				CASE(POLL_ERR)
+				CASE(POLL_PRI)
+				CASE(POLL_HUP)
+			}
+			break;
+	}
+#undef CASE
+
+	static char buffer[32];
+	sprintf(buffer, "%d", code);
+	return buffer;
+}
+
+
+std::string
+signal_info(siginfo_t& info)
+{
+	static char buffer[32];
+	std::string string;
+
+	string.reserve(256);
+
+	string += "{";
+	string += "si_signo=";
+	string += signal_name(info.si_signo);
+	string += ", si_code=";
+	string += signal_code(info.si_signo, info.si_code);
+
+	if (info.si_errno != 0) {
+		string += ", si_errno=0x";
+		sprintf(buffer, "%x", info.si_errno);
+		string += buffer;
+	}
+
+	string += ", si_pid=";
+	sprintf(buffer, "%d", (int)info.si_pid);
+	string += buffer;
+	string += ", si_uid=";
+	sprintf(buffer, "%d", (int)info.si_uid);
+	string += buffer;
+
+	if (info.si_signo == SIGILL || info.si_signo == SIGFPE || info.si_signo == SIGSEGV
+		|| info.si_signo == SIGBUS || info.si_signo == SIGTRAP) {
+		string += ", si_addr=";
+		sprintf(buffer, "%p", info.si_addr);
+		string += buffer;
+	}
+
+	if (info.si_signo == SIGCHLD) {
+		string += ", si_status=";
+		sprintf(buffer, "%d", info.si_status);
+		string += buffer;
+	}
+
+	if (info.si_signo == SIGPOLL) {
+		string += ", si_band=";
+		sprintf(buffer, "%ld", info.si_band);
+		string += buffer;
+	}
+
+	string += ", si_value=";
+	sprintf(buffer, "%p", info.si_value.sival_ptr);
+	string += buffer;
+	string += "}";
+
+	return string;
+}

src/bin/debug/strace/signals.h

@@ -0,0 +1,18 @@
+/*
+ * Copyright 2023, Trung Nguyen, [email protected].
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef STRACE_SIGNAL_H
+#define STRACE_SIGNAL_H
+
+
+#include <string>
+
+#include <signal.h>
+
+
+std::string signal_name(int signal);
+std::string signal_info(siginfo_t& info);
+
+
+#endif	// STRACE_SIGNAL_H

src/bin/debug/strace/strace.cpp

@@ -25,6 +25,7 @@
 
 #include "debug_utils.h"
 
+#include "signals.h"
 #include "Context.h"
 #include "MemoryReader.h"
 #include "Syscall.h"
@@ -115,44 +116,6 @@ static const char *kTerminalTextMagenta	= "\33[35m";
 static const char *kTerminalTextBlue	= "\33[34m";
 
 
-// signal names
-static const char *kSignalName[] = {
-	/*  0 */ "SIG0",
-	/*  1 */ "SIGHUP",
-	/*  2 */ "SIGINT",
-	/*  3 */ "SIGQUIT",
-	/*  4 */ "SIGILL",
-	/*  5 */ "SIGCHLD",
-	/*  6 */ "SIGABRT",
-	/*  7 */ "SIGPIPE",
-	/*  8 */ "SIGFPE",
-	/*  9 */ "SIGKILL",
-	/* 10 */ "SIGSTOP",
-	/* 11 */ "SIGSEGV",
-	/* 12 */ "SIGCONT",
-	/* 13 */ "SIGTSTP",
-	/* 14 */ "SIGALRM",
-	/* 15 */ "SIGTERM",
-	/* 16 */ "SIGTTIN",
-	/* 17 */ "SIGTTOU",
-	/* 18 */ "SIGUSR1",
-	/* 19 */ "SIGUSR2",
-	/* 20 */ "SIGWINCH",
-	/* 21 */ "SIGKILLTHR",
-	/* 22 */ "SIGTRAP",
-	/* 23 */ "SIGPOLL",
-	/* 24 */ "SIGPROF",
-	/* 25 */ "SIGSYS",
-	/* 26 */ "SIGURG",
-	/* 27 */ "SIGVTALRM",
-	/* 28 */ "SIGXCPU",
-	/* 29 */ "SIGXFSZ",
-	/* 30 */ "SIGBUS",
-	/* 31 */ "SIGRESERVED1",
-	/* 32 */ "SIGRESERVED2",
-};
-
-
 // command line args
 static int sArgc;
 static const char *const *sArgv;
@@ -507,18 +470,6 @@ print_syscall(FILE *outputFile, Syscall* syscall, debug_post_syscall &message,
 }
 
 
-static const char *
-signal_name(int signal)
-{
-	if (signal >= 0 && signal <= SIGRESERVED2)
-		return kSignalName[signal];
-
-	static char buffer[32];
-	sprintf(buffer, "%d", signal);
-	return buffer;
-}
-
-
 static void
 print_signal(FILE *outputFile, debug_signal_received &message,
 	bool colorize)
@@ -529,13 +480,14 @@ print_signal(FILE *outputFile, debug_signal_received &message,
 
 	// print signal name
 	if (colorize) {
-		print_to_string(&string, &length, "[%6" B_PRId32 "] --- %s%s (%s) %s---\n",
+		print_to_string(&string, &length, "[%6" B_PRId32 "] --- %s%s (%s)%s %s ---\n",
-			message.origin.thread, kTerminalTextRed, signal_name(signalNumber),
+			message.origin.thread, kTerminalTextRed,
-			strsignal(signalNumber), kTerminalTextNormal);
+			signal_name(signalNumber).c_str(), strsignal(signalNumber),
+			kTerminalTextNormal, signal_info(message.info).c_str());
 	} else {
-		print_to_string(&string, &length, "[%6" B_PRId32 "] --- %s (%s) ---\n",
+		print_to_string(&string, &length, "[%6" B_PRId32 "] --- %s (%s) %s ---\n",
-			message.origin.thread, signal_name(signalNumber),
+			message.origin.thread, signal_name(signalNumber).c_str(),
-			strsignal(signalNumber));
+			strsignal(signalNumber), signal_info(message.info).c_str());
 	}
 
 	print_buffer(outputFile, buffer, sizeof(buffer) - length);

src/system/kernel/debug/user_debugger.cpp

@@ -928,7 +928,8 @@ user_debug_exception_occurred(debug_exception_type exception, int signal)
 
 
 bool
-user_debug_handle_signal(int signal, struct sigaction *handler, bool deadly)
+user_debug_handle_signal(int signal, struct sigaction *handler, siginfo_t *info,
+	bool deadly)
 {
 	// check, if a debugger is installed and is interested in signals
 	Thread *thread = thread_get_current_thread();
@@ -942,6 +943,7 @@ user_debug_handle_signal(int signal, struct sigaction *handler, bool deadly)
 	debug_signal_received message;
 	message.signal = signal;
 	message.handler = *handler;
+	message.info = *info;
 	message.deadly = deadly;
 
 	status_t result = thread_hit_debug_event(B_DEBUGGER_MESSAGE_SIGNAL_RECEIVED,

src/system/kernel/signal.cpp

@@ -821,8 +821,19 @@ notify_debugger(Thread* thread, Signal* signal, struct sigaction& handler,
 
 	threadDebugInfoLocker.Unlock();
 
+	siginfo_t info;
+	info.si_signo = signal->Number();
+	info.si_code = signal->SignalCode();
+	info.si_errno = signal->ErrorCode();
+	info.si_pid = signal->SendingProcess();
+	info.si_uid = signal->SendingUser();
+	info.si_addr = signal->Address();
+	info.si_status = signal->Status();
+	info.si_band = signal->PollBand();
+	info.si_value = signal->UserValue();
+
 	// deliver the event
-	return user_debug_handle_signal(signal->Number(), &handler, deadly);
+	return user_debug_handle_signal(signal->Number(), &handler, &info, deadly);
 }