llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-lldb Author: Jacob Lalonde (Jlalond) <details> <summary>Changes</summary> Recently, I was on an issue that generated a large number of Coredumps, and every time in both LLDB and GDB the signal was just `SIGSEGV`. This was frustrating because we would expect a `SIGSEGV` to have an address, or ideally even bounds. After some digging I found the `si_code` consistently was -6. With some help from [@<!-- -->cdown](https://github.com/cdown), we found neither LLDB or GDB supports the si_codes sent from [user space](https://github.com/torvalds/linux/blob/master/include/uapi/asm-generic/siginfo.h#L185). Excerpted from the sigaction man page. ``` For a regular signal, the following list shows the values which can be placed in si_code for any signal, along with the reason that the signal was generated. ``` For which I added all of the si_codes to every Linux signal. Now for the Coredump that triggered this whole investigation we get the accurate and now very informative summary. <img width="524" alt="image" src="https://github.com/user-attachments/assets/5149f781-ef21-4491-a077-8fac862fbc20"; /> Importantly, I didn't add an equivalent of `siginfo_t` to ELFSigInfo, and I think we should open an issue for this to make a (build) platform agnostic struct of siginfo_t. I'll defer to your expertise @<!-- -->labath and @<!-- -->DavidSpickett --- Patch is 24.96 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/140150.diff 6 Files Affected: - (modified) lldb/include/lldb/Target/UnixSignals.h (+4-2) - (modified) lldb/source/Plugins/Process/Utility/LinuxSignals.cpp (+88-66) - (modified) lldb/source/Plugins/Process/elf-core/ThreadElfCore.cpp (+25-16) - (modified) lldb/source/Plugins/Process/elf-core/ThreadElfCore.h (+23-15) - (modified) lldb/source/Target/UnixSignals.cpp (+9-6) - (modified) lldb/unittests/Signals/UnixSignalsTest.cpp (+9) ``````````diff diff --git a/lldb/include/lldb/Target/UnixSignals.h b/lldb/include/lldb/Target/UnixSignals.h index b3605ccefddbe..a1807d69f329b 100644 --- a/lldb/include/lldb/Target/UnixSignals.h +++ b/lldb/include/lldb/Target/UnixSignals.h @@ -36,7 +36,9 @@ class UnixSignals { std::optional<int32_t> code = std::nullopt, std::optional<lldb::addr_t> addr = std::nullopt, std::optional<lldb::addr_t> lower = std::nullopt, - std::optional<lldb::addr_t> upper = std::nullopt) const; + std::optional<lldb::addr_t> upper = std::nullopt, + std::optional<uint32_t> pid = std::nullopt, + std::optional<uint32_t> uid = std::nullopt) const; bool SignalIsValid(int32_t signo) const; @@ -105,7 +107,7 @@ class UnixSignals { llvm::StringRef description, llvm::StringRef alias = llvm::StringRef()); - enum SignalCodePrintOption { None, Address, Bounds }; + enum SignalCodePrintOption { None, Address, Bounds, Sender }; // Instead of calling this directly, use a ADD_SIGCODE macro to get compile // time checks when on the native platform. diff --git a/lldb/source/Plugins/Process/Utility/LinuxSignals.cpp b/lldb/source/Plugins/Process/Utility/LinuxSignals.cpp index 9c4fe55147a28..76c32e376eb4b 100644 --- a/lldb/source/Plugins/Process/Utility/LinuxSignals.cpp +++ b/lldb/source/Plugins/Process/Utility/LinuxSignals.cpp @@ -38,6 +38,28 @@ #define ADD_SIGCODE(signal_name, signal_value, code_name, code_value, ...) \ AddSignalCode(signal_value, code_value, __VA_ARGS__) #endif /* if defined(__linux__) && !defined(__mips__) */ +// See siginfo.h in the Linux Kernel, these codes can be sent for any signal. +#define ADD_LINUX_SIGNAL(signo, name, ...) \ + AddSignal(signo, name, __VA_ARGS__); \ + ADD_SIGCODE(signo, signo, SI_QUEUE, -1, "sent by sigqueue", \ + SignalCodePrintOption::Sender); \ + ADD_SIGCODE(signo, signo, SI_TIMER, -2, "sent by timer expiration", \ + SignalCodePrintOption::Sender); \ + ADD_SIGCODE(signo, signo, SI_MESGQ, -3, \ + "sent by real time mesq state change", \ + SignalCodePrintOption::Sender); \ + ADD_SIGCODE(signo, signo, SI_ASYNCIO, -4, "sent by AIO completion", \ + SignalCodePrintOption::Sender); \ + ADD_SIGCODE(signo, signo, SI_SIGIO, -5, "sent by queued SIGIO", \ + SignalCodePrintOption::Sender); \ + ADD_SIGCODE(signo, signo, SI_TKILL, -6, "sent by tkill system call", \ + SignalCodePrintOption::Sender); \ + ADD_SIGCODE(signo, signo, SI_DETHREAD, -7, \ + "sent by execve() killing subsidiary threads", \ + SignalCodePrintOption::Sender); \ + ADD_SIGCODE(signo, signo, SI_ASYNCNL, -60, \ + "sent by glibc async name lookup completion", \ + SignalCodePrintOption::Sender); using namespace lldb_private; @@ -46,13 +68,13 @@ LinuxSignals::LinuxSignals() : UnixSignals() { Reset(); } void LinuxSignals::Reset() { m_signals.clear(); // clang-format off - // SIGNO NAME SUPPRESS STOP NOTIFY DESCRIPTION - // ====== ============== ======== ====== ====== =================================================== - AddSignal(1, "SIGHUP", false, true, true, "hangup"); - AddSignal(2, "SIGINT", true, true, true, "interrupt"); - AddSignal(3, "SIGQUIT", false, true, true, "quit"); + // SIGNO NAME SUPPRESS STOP NOTIFY DESCRIPTION + // ====== ============== ======== ====== ====== =================================================== + ADD_LINUX_SIGNAL(1, "SIGHUP", false, true, true, "hangup"); + ADD_LINUX_SIGNAL(2, "SIGINT", true, true, true, "interrupt"); + ADD_LINUX_SIGNAL(3, "SIGQUIT", false, true, true, "quit"); - AddSignal(4, "SIGILL", false, true, true, "illegal instruction"); + ADD_LINUX_SIGNAL(4, "SIGILL", false, true, true, "illegal instruction"); ADD_SIGCODE(SIGILL, 4, ILL_ILLOPC, 1, "illegal opcode"); ADD_SIGCODE(SIGILL, 4, ILL_ILLOPN, 2, "illegal operand"); ADD_SIGCODE(SIGILL, 4, ILL_ILLADR, 3, "illegal addressing mode"); @@ -62,15 +84,15 @@ void LinuxSignals::Reset() { ADD_SIGCODE(SIGILL, 4, ILL_COPROC, 7, "coprocessor error"); ADD_SIGCODE(SIGILL, 4, ILL_BADSTK, 8, "internal stack error"); - AddSignal(5, "SIGTRAP", true, true, true, "trace trap (not reset when caught)"); - AddSignal(6, "SIGABRT", false, true, true, "abort()/IOT trap", "SIGIOT"); + ADD_LINUX_SIGNAL(5, "SIGTRAP", true, true, true, "trace trap (not reset when caught)"); + ADD_LINUX_SIGNAL(6, "SIGABRT", false, true, true, "abort()/IOT trap", "SIGIOT"); - AddSignal(7, "SIGBUS", false, true, true, "bus error"); + ADD_LINUX_SIGNAL(7, "SIGBUS", false, true, true, "bus error"); ADD_SIGCODE(SIGBUS, 7, BUS_ADRALN, 1, "illegal alignment"); ADD_SIGCODE(SIGBUS, 7, BUS_ADRERR, 2, "illegal address"); ADD_SIGCODE(SIGBUS, 7, BUS_OBJERR, 3, "hardware error"); - AddSignal(8, "SIGFPE", false, true, true, "floating point exception"); + ADD_LINUX_SIGNAL(8, "SIGFPE", false, true, true, "floating point exception"); ADD_SIGCODE(SIGFPE, 8, FPE_INTDIV, 1, "integer divide by zero"); ADD_SIGCODE(SIGFPE, 8, FPE_INTOVF, 2, "integer overflow"); ADD_SIGCODE(SIGFPE, 8, FPE_FLTDIV, 3, "floating point divide by zero"); @@ -80,10 +102,10 @@ void LinuxSignals::Reset() { ADD_SIGCODE(SIGFPE, 8, FPE_FLTINV, 7, "floating point invalid operation"); ADD_SIGCODE(SIGFPE, 8, FPE_FLTSUB, 8, "subscript out of range"); - AddSignal(9, "SIGKILL", false, true, true, "kill"); - AddSignal(10, "SIGUSR1", false, true, true, "user defined signal 1"); + ADD_LINUX_SIGNAL(9, "SIGKILL", false, true, true, "kill"); + ADD_LINUX_SIGNAL(10, "SIGUSR1", false, true, true, "user defined signal 1"); - AddSignal(11, "SIGSEGV", false, true, true, "segmentation violation"); + ADD_LINUX_SIGNAL(11, "SIGSEGV", false, true, true, "segmentation violation"); ADD_SIGCODE(SIGSEGV, 11, SEGV_MAPERR, 1, "address not mapped to object", SignalCodePrintOption::Address); ADD_SIGCODE(SIGSEGV, 11, SEGV_ACCERR, 2, "invalid permissions for mapped object", SignalCodePrintOption::Address); ADD_SIGCODE(SIGSEGV, 11, SEGV_BNDERR, 3, "failed address bounds checks", SignalCodePrintOption::Bounds); @@ -94,58 +116,58 @@ void LinuxSignals::Reset() { // codes. One way to get this is via unaligned SIMD loads. Treat it as invalid address. ADD_SIGCODE(SIGSEGV, 11, SI_KERNEL, 0x80, "invalid address", SignalCodePrintOption::Address); - AddSignal(12, "SIGUSR2", false, true, true, "user defined signal 2"); - AddSignal(13, "SIGPIPE", false, true, true, "write to pipe with reading end closed"); - AddSignal(14, "SIGALRM", false, false, false, "alarm"); - AddSignal(15, "SIGTERM", false, true, true, "termination requested"); - AddSignal(16, "SIGSTKFLT", false, true, true, "stack fault"); - AddSignal(17, "SIGCHLD", false, false, true, "child status has changed", "SIGCLD"); - AddSignal(18, "SIGCONT", false, false, true, "process continue"); - AddSignal(19, "SIGSTOP", true, true, true, "process stop"); - AddSignal(20, "SIGTSTP", false, true, true, "tty stop"); - AddSignal(21, "SIGTTIN", false, true, true, "background tty read"); - AddSignal(22, "SIGTTOU", false, true, true, "background tty write"); - AddSignal(23, "SIGURG", false, true, true, "urgent data on socket"); - AddSignal(24, "SIGXCPU", false, true, true, "CPU resource exceeded"); - AddSignal(25, "SIGXFSZ", false, true, true, "file size limit exceeded"); - AddSignal(26, "SIGVTALRM", false, true, true, "virtual time alarm"); - AddSignal(27, "SIGPROF", false, false, false, "profiling time alarm"); - AddSignal(28, "SIGWINCH", false, true, true, "window size changes"); - AddSignal(29, "SIGIO", false, true, true, "input/output ready/Pollable event", "SIGPOLL"); - AddSignal(30, "SIGPWR", false, true, true, "power failure"); - AddSignal(31, "SIGSYS", false, true, true, "invalid system call"); - AddSignal(32, "SIG32", false, false, false, "threading library internal signal 1"); - AddSignal(33, "SIG33", false, false, false, "threading library internal signal 2"); - AddSignal(34, "SIGRTMIN", false, false, false, "real time signal 0"); - AddSignal(35, "SIGRTMIN+1", false, false, false, "real time signal 1"); - AddSignal(36, "SIGRTMIN+2", false, false, false, "real time signal 2"); - AddSignal(37, "SIGRTMIN+3", false, false, false, "real time signal 3"); - AddSignal(38, "SIGRTMIN+4", false, false, false, "real time signal 4"); - AddSignal(39, "SIGRTMIN+5", false, false, false, "real time signal 5"); - AddSignal(40, "SIGRTMIN+6", false, false, false, "real time signal 6"); - AddSignal(41, "SIGRTMIN+7", false, false, false, "real time signal 7"); - AddSignal(42, "SIGRTMIN+8", false, false, false, "real time signal 8"); - AddSignal(43, "SIGRTMIN+9", false, false, false, "real time signal 9"); - AddSignal(44, "SIGRTMIN+10", false, false, false, "real time signal 10"); - AddSignal(45, "SIGRTMIN+11", false, false, false, "real time signal 11"); - AddSignal(46, "SIGRTMIN+12", false, false, false, "real time signal 12"); - AddSignal(47, "SIGRTMIN+13", false, false, false, "real time signal 13"); - AddSignal(48, "SIGRTMIN+14", false, false, false, "real time signal 14"); - AddSignal(49, "SIGRTMIN+15", false, false, false, "real time signal 15"); - AddSignal(50, "SIGRTMAX-14", false, false, false, "real time signal 16"); // switching to SIGRTMAX-xxx to match "kill -l" output - AddSignal(51, "SIGRTMAX-13", false, false, false, "real time signal 17"); - AddSignal(52, "SIGRTMAX-12", false, false, false, "real time signal 18"); - AddSignal(53, "SIGRTMAX-11", false, false, false, "real time signal 19"); - AddSignal(54, "SIGRTMAX-10", false, false, false, "real time signal 20"); - AddSignal(55, "SIGRTMAX-9", false, false, false, "real time signal 21"); - AddSignal(56, "SIGRTMAX-8", false, false, false, "real time signal 22"); - AddSignal(57, "SIGRTMAX-7", false, false, false, "real time signal 23"); - AddSignal(58, "SIGRTMAX-6", false, false, false, "real time signal 24"); - AddSignal(59, "SIGRTMAX-5", false, false, false, "real time signal 25"); - AddSignal(60, "SIGRTMAX-4", false, false, false, "real time signal 26"); - AddSignal(61, "SIGRTMAX-3", false, false, false, "real time signal 27"); - AddSignal(62, "SIGRTMAX-2", false, false, false, "real time signal 28"); - AddSignal(63, "SIGRTMAX-1", false, false, false, "real time signal 29"); - AddSignal(64, "SIGRTMAX", false, false, false, "real time signal 30"); + ADD_LINUX_SIGNAL(12, "SIGUSR2", false, true, true, "user defined signal 2"); + ADD_LINUX_SIGNAL(13, "SIGPIPE", false, true, true, "write to pipe with reading end closed"); + ADD_LINUX_SIGNAL(14, "SIGALRM", false, false, false, "alarm"); + ADD_LINUX_SIGNAL(15, "SIGTERM", false, true, true, "termination requested"); + ADD_LINUX_SIGNAL(16, "SIGSTKFLT", false, true, true, "stack fault"); + ADD_LINUX_SIGNAL(17, "SIGCHLD", false, false, true, "child status has changed", "SIGCLD"); + ADD_LINUX_SIGNAL(18, "SIGCONT", false, false, true, "process continue"); + ADD_LINUX_SIGNAL(19, "SIGSTOP", true, true, true, "process stop"); + ADD_LINUX_SIGNAL(20, "SIGTSTP", false, true, true, "tty stop"); + ADD_LINUX_SIGNAL(21, "SIGTTIN", false, true, true, "background tty read"); + ADD_LINUX_SIGNAL(22, "SIGTTOU", false, true, true, "background tty write"); + ADD_LINUX_SIGNAL(23, "SIGURG", false, true, true, "urgent data on socket"); + ADD_LINUX_SIGNAL(24, "SIGXCPU", false, true, true, "CPU resource exceeded"); + ADD_LINUX_SIGNAL(25, "SIGXFSZ", false, true, true, "file size limit exceeded"); + ADD_LINUX_SIGNAL(26, "SIGVTALRM", false, true, true, "virtual time alarm"); + ADD_LINUX_SIGNAL(27, "SIGPROF", false, false, false, "profiling time alarm"); + ADD_LINUX_SIGNAL(28, "SIGWINCH", false, true, true, "window size changes"); + ADD_LINUX_SIGNAL(29, "SIGIO", false, true, true, "input/output ready/Pollable event", "SIGPOLL"); + ADD_LINUX_SIGNAL(30, "SIGPWR", false, true, true, "power failure"); + ADD_LINUX_SIGNAL(31, "SIGSYS", false, true, true, "invalid system call"); + ADD_LINUX_SIGNAL(32, "SIG32", false, false, false, "threading library internal signal 1"); + ADD_LINUX_SIGNAL(33, "SIG33", false, false, false, "threading library internal signal 2"); + ADD_LINUX_SIGNAL(34, "SIGRTMIN", false, false, false, "real time signal 0"); + ADD_LINUX_SIGNAL(35, "SIGRTMIN+1", false, false, false, "real time signal 1"); + ADD_LINUX_SIGNAL(36, "SIGRTMIN+2", false, false, false, "real time signal 2"); + ADD_LINUX_SIGNAL(37, "SIGRTMIN+3", false, false, false, "real time signal 3"); + ADD_LINUX_SIGNAL(38, "SIGRTMIN+4", false, false, false, "real time signal 4"); + ADD_LINUX_SIGNAL(39, "SIGRTMIN+5", false, false, false, "real time signal 5"); + ADD_LINUX_SIGNAL(40, "SIGRTMIN+6", false, false, false, "real time signal 6"); + ADD_LINUX_SIGNAL(41, "SIGRTMIN+7", false, false, false, "real time signal 7"); + ADD_LINUX_SIGNAL(42, "SIGRTMIN+8", false, false, false, "real time signal 8"); + ADD_LINUX_SIGNAL(43, "SIGRTMIN+9", false, false, false, "real time signal 9"); + ADD_LINUX_SIGNAL(44, "SIGRTMIN+10", false, false, false, "real time signal 10"); + ADD_LINUX_SIGNAL(45, "SIGRTMIN+11", false, false, false, "real time signal 11"); + ADD_LINUX_SIGNAL(46, "SIGRTMIN+12", false, false, false, "real time signal 12"); + ADD_LINUX_SIGNAL(47, "SIGRTMIN+13", false, false, false, "real time signal 13"); + ADD_LINUX_SIGNAL(48, "SIGRTMIN+14", false, false, false, "real time signal 14"); + ADD_LINUX_SIGNAL(49, "SIGRTMIN+15", false, false, false, "real time signal 15"); + ADD_LINUX_SIGNAL(50, "SIGRTMAX-14", false, false, false, "real time signal 16"); // switching to SIGRTMAX-xxx to match "kill -l" output + ADD_LINUX_SIGNAL(51, "SIGRTMAX-13", false, false, false, "real time signal 17"); + ADD_LINUX_SIGNAL(52, "SIGRTMAX-12", false, false, false, "real time signal 18"); + ADD_LINUX_SIGNAL(53, "SIGRTMAX-11", false, false, false, "real time signal 19"); + ADD_LINUX_SIGNAL(54, "SIGRTMAX-10", false, false, false, "real time signal 20"); + ADD_LINUX_SIGNAL(55, "SIGRTMAX-9", false, false, false, "real time signal 21"); + ADD_LINUX_SIGNAL(56, "SIGRTMAX-8", false, false, false, "real time signal 22"); + ADD_LINUX_SIGNAL(57, "SIGRTMAX-7", false, false, false, "real time signal 23"); + ADD_LINUX_SIGNAL(58, "SIGRTMAX-6", false, false, false, "real time signal 24"); + ADD_LINUX_SIGNAL(59, "SIGRTMAX-5", false, false, false, "real time signal 25"); + ADD_LINUX_SIGNAL(60, "SIGRTMAX-4", false, false, false, "real time signal 26"); + ADD_LINUX_SIGNAL(61, "SIGRTMAX-3", false, false, false, "real time signal 27"); + ADD_LINUX_SIGNAL(62, "SIGRTMAX-2", false, false, false, "real time signal 28"); + ADD_LINUX_SIGNAL(63, "SIGRTMAX-1", false, false, false, "real time signal 29"); + ADD_LINUX_SIGNAL(64, "SIGRTMAX", false, false, false, "real time signal 30"); // clang-format on } diff --git a/lldb/source/Plugins/Process/elf-core/ThreadElfCore.cpp b/lldb/source/Plugins/Process/elf-core/ThreadElfCore.cpp index a0cd0ee5025bd..907e009bc7b80 100644 --- a/lldb/source/Plugins/Process/elf-core/ThreadElfCore.cpp +++ b/lldb/source/Plugins/Process/elf-core/ThreadElfCore.cpp @@ -584,22 +584,26 @@ Status ELFLinuxSigInfo::Parse(const DataExtractor &data, const ArchSpec &arch, // 64b ELF have a 4 byte pad. if (data.GetAddressByteSize() == 8) offset += 4; - // Not every stop signal has a valid address, but that will get resolved in - // the unix_signals.GetSignalDescription() call below. - if (unix_signals.GetShouldStop(si_signo)) { + + if (si_code < 0) { + sifields.kill.pid = data.GetU32(&offset); + sifields.kill.uid = data.GetU32(&offset); + } else if (unix_signals.GetShouldStop(si_signo)) { + // Not every stop signal has a valid address, but that will get resolved in + // the unix_signals.GetSignalDescription() call below. // Instead of memcpy we call all these individually as the extractor will // handle endianness for us. - sigfault.si_addr = data.GetAddress(&offset); - sigfault.si_addr_lsb = data.GetU16(&offset); - if (data.GetByteSize() - offset >= sizeof(sigfault.bounds)) { - sigfault.bounds._addr_bnd._lower = data.GetAddress(&offset); - sigfault.bounds._addr_bnd._upper = data.GetAddress(&offset); - sigfault.bounds._pkey = data.GetU32(&offset); + sifields.sigfault.si_addr = data.GetAddress(&offset); + sifields.sigfault.si_addr_lsb = data.GetU16(&offset); + if (data.GetByteSize() - offset >= sizeof(sifields.sigfault.bounds)) { + sifields.sigfault.bounds._addr_bnd._lower = data.GetAddress(&offset); + sifields.sigfault.bounds._addr_bnd._upper = data.GetAddress(&offset); + sifields.sigfault.bounds._pkey = data.GetU32(&offset); } else { // Set these to 0 so we don't use bogus data for the description. - sigfault.bounds._addr_bnd._lower = 0; - sigfault.bounds._addr_bnd._upper = 0; - sigfault.bounds._pkey = 0; + sifields.sigfault.bounds._addr_bnd._lower = 0; + sifields.sigfault.bounds._addr_bnd._upper = 0; + sifields.sigfault.bounds._pkey = 0; } } @@ -609,13 +613,18 @@ Status ELFLinuxSigInfo::Parse(const DataExtractor &data, const ArchSpec &arch, std::string ELFLinuxSigInfo::GetDescription( const lldb_private::UnixSignals &unix_signals) const { if (unix_signals.GetShouldStop(si_signo) && note_type == eNT_SIGINFO) { - if (sigfault.bounds._addr_bnd._upper != 0) + if (si_code < 0) + return unix_signals.GetSignalDescription( + si_signo, si_code, std::nullopt, std::nullopt, std::nullopt, + sifields.kill.pid, sifields.kill.uid); + else if (sifields.sigfault.bounds._addr_bnd._upper != 0) return unix_signals.GetSignalDescription( - si_signo, si_code, sigfault.si_addr, sigfault.bounds._addr_bnd._lower, - sigfault.bounds._addr_bnd._upper); + si_signo, si_code, sifields.sigfault.si_addr, + sifields.sigfault.bounds._addr_bnd._lower, + sifie... [truncated] `````````` </details> https://github.com/llvm/llvm-project/pull/140150 _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
