From 3ab752b8ca7878246c3d7f8a338a8bc3b0de26dd Mon Sep 17 00:00:00 2001 From: PoroCYon <3253268+PoroCYon@users.noreply.github.com> Date: Sun, 22 Oct 2023 15:35:31 +0200 Subject: GDB stub (#1583) * gdbstub beginnings * gdbstub: finish gdb impl things, next up is integration with melonDS * holy fuck the gdbstub works * gdb breakpoints work, but there's a mysterious crash on continue * fix memory corruption that sometimes happened, and make resetting the console thru gdb work * remove some gdb debug printing * fix things in gdbstub * separate option for enabling gdbstub * add mode-dependent CPU registers * C++ize the GDBstub code * add gdbstub config in emu settings dialog * make sure gdb is disabled when jit is enabled * Remove unnecessary compiler flags, mark ARMJIT assembly code as no-execute-stack This hardens the binary a little bit against common exploitation methods * add option to wait for debugger attach on startup * only insert GNU stack notes on linux * disable gdbstub enable checkbox when jit is enabled * fix non-linux incompatibilities * enable gdbstub by default * fix issues with gdbstub settings disable stuff * format stuff * update gdb test code * Fix segfault when calling StubCallbacks->GetCPU() C++ overrides are hard. Please I'm just a lowly C programmer. * fix packet size not being sent correctly Thanks to @GlowingUmbreon on Github for troubleshooting this * fix select(2) calls (i should read docs more properly) * fix GDB command sequencing/parsing issue (hopefully) * [GDB] implement no-ack mode * fix sending ack on handshake * get lldb to work --- src/debug/gdb_test/.gitignore | 2 + src/debug/gdb_test/Makefile | 28 ++++++++++ src/debug/gdb_test/main.cpp | 124 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 154 insertions(+) create mode 100644 src/debug/gdb_test/.gitignore create mode 100644 src/debug/gdb_test/Makefile create mode 100644 src/debug/gdb_test/main.cpp (limited to 'src/debug/gdb_test') diff --git a/src/debug/gdb_test/.gitignore b/src/debug/gdb_test/.gitignore new file mode 100644 index 0000000..218500b --- /dev/null +++ b/src/debug/gdb_test/.gitignore @@ -0,0 +1,2 @@ +obj/ +test-gdb diff --git a/src/debug/gdb_test/Makefile b/src/debug/gdb_test/Makefile new file mode 100644 index 0000000..e835795 --- /dev/null +++ b/src/debug/gdb_test/Makefile @@ -0,0 +1,28 @@ + +default: all + +all: test-gdb + +CPPFLAGS += -Werror=implicit-function-declaration -Werror=int-conversion \ + -Werror=return-type -Werror=uninitialized \ + -I../ -I../../ -Og -g -Wall \ + -Wno-switch -Wno-pointer-sign + +obj/: + @mkdir -vp "$@" + +test-gdb: obj/GdbProto.o obj/GdbStub.o obj/GdbCmds.o obj/main.o obj/CRC32.o + $(CXX) $(CPPFLAGS) $(LDFLAGS) -o "$@" $^ + +obj/Gdb%.o: ../Gdb%.cpp obj/ + $(CXX) $(CPPFLAGS) -c -o "$@" "$<" + +obj/main.o: main.cpp obj/ + $(CXX) $(CPPFLAGS) -c -o "$@" "$<" + +obj/CRC32.o: ../../CRC32.cpp obj/ + $(CXX) $(CPPFLAGS) -c -o "$@" "$<" + +clean: + @$(RM) -rv obj/ test-gdb + diff --git a/src/debug/gdb_test/main.cpp b/src/debug/gdb_test/main.cpp new file mode 100644 index 0000000..afdfa2c --- /dev/null +++ b/src/debug/gdb_test/main.cpp @@ -0,0 +1,124 @@ + +#include +#include +#include +#include + +#include "GdbStub.h" +#include "Platform.h" + +class Debug : public Gdb::StubCallbacks +{ +public: + Debug(){} + ~Debug(){} + + int GetCPU() const override { return 9; } + + u32 ReadReg(Gdb::Register reg) override + { + printf("[==>] read reg %d\n", (int)reg); + if (reg == Gdb::Register::pc) return 0x000000df; // cpsr: irq,fiq disabled, arm, sys mode + else return 0x69420; + } + void WriteReg(Gdb::Register reg, u32 value) override + { + printf("[==>] write reg %d: 0x%08x\n", (int)reg, value); + } + + u32 ReadMem(u32 addr, int len) override + { + static const u32 words[] = { + 0xeafffffe, + 0xe0211002, + 0xe12fff1e, + 0 + }; + + printf("[==>] read mem 0x%08x (size %u)\n", addr, len); + + // $: b $ (arm) + return words[(addr>>2)&3] & ((1uLL<] write addr 0x%08x (size %u): 0x%08x\n", addr, len, value); + } + + void ResetGdb() override + { + printf("[==>] RESET!!!\n"); + } + int RemoteCmd(const u8* cmd, size_t len) override + { + printf("[==>] Rcmd: %s\n", cmd); + return 0; + } +}; + +int main(int argc, char** argv) { + Debug debug; + + Gdb::GdbStub stub(&debug, (argc > 1) ? atoi(argv[1]) : 3333); + if (!stub.Init()) return 1; + + do + { + while (true) + { + Gdb::StubState s = stub.Poll(); + + if (s == Gdb::StubState::None || s == Gdb::StubState::NoConn) + { + struct timespec ts; + ts.tv_sec = 0; + ts.tv_nsec = 1000*1000; // 1 ms + nanosleep(&ts, NULL); + continue; + } + + switch (s) + { + case Gdb::StubState::Attach: + printf("[==>] attached\n"); + break; + case Gdb::StubState::Break: + printf("[==>] break execution\n"); + stub.SignalStatus(Gdb::TgtStatus::BreakReq, ~(u32)0); + break; + case Gdb::StubState::Continue: + printf("[==>] continue execution\n"); + // TODO: send signal status on SIGSTOP? eh. + break; + case Gdb::StubState::Step: + printf("[==>] single-step\n"); + stub.SignalStatus(Gdb::TgtStatus::SingleStep, ~(u32)0); + break; + case Gdb::StubState::Disconnect: + printf("[==>] disconnect\n"); + stub.SignalStatus(Gdb::TgtStatus::None, ~(u32)0); + break; + } + + if (s == Gdb::StubState::Disconnect) break; + } + } + while (false); + + stub.Close(); + return 0; +} + +namespace Platform +{ +void Log(LogLevel level, const char* fmt, ...) +{ + if (fmt == nullptr) return; + + va_list args; + va_start(args, fmt); + vprintf(fmt, args); + va_end(args); +} +} + -- cgit v1.2.3