/** * Queries symbol information by symbol name. * * @returns IPRT status code. * @retval VERR_DBG_NO_SYMBOLS if there aren't any symbols. * @retval VERR_SYMBOL_NOT_FOUND if no suitable symbol was found. * @retval VERR_DBG_SYMBOL_NAME_OUT_OF_RANGE if the symbol name is too long or * short. * @retval VERR_NO_MEMORY if RTDbgSymbolAlloc fails. * * @param hDbgMod The module handle. * @param pszSymbol The symbol name. * @param ppSymInfo Where to store the pointer to the returned * symbol information. Always set. Free with * RTDbgSymbolFree. */ RTDECL(int) RTDbgModSymbolByNameA(RTDBGMOD hDbgMod, const char *pszSymbol, PRTDBGSYMBOL *ppSymInfo) { AssertPtr(ppSymInfo); *ppSymInfo = NULL; PRTDBGSYMBOL pSymInfo = RTDbgSymbolAlloc(); if (!pSymInfo) return VERR_NO_MEMORY; int rc = RTDbgModSymbolByName(hDbgMod, pszSymbol, pSymInfo); if (RT_SUCCESS(rc)) *ppSymInfo = pSymInfo; else RTDbgSymbolFree(pSymInfo); return rc; }
/** * @interface_method_impl{DBGFOSIDMESG,pfnQueryKernelLog} */ static DECLCALLBACK(int) dbgDiggerLinuxIDmsg_QueryKernelLog(PDBGFOSIDMESG pThis, PUVM pUVM, uint32_t fFlags, uint32_t cMessages, char *pszBuf, size_t cbBuf, size_t *pcbActual) { PDBGDIGGERLINUX pData = RT_FROM_MEMBER(pThis, DBGDIGGERLINUX, IDmesg); if (cMessages < 1) return VERR_INVALID_PARAMETER; /* * Resolve the symbols we need and read their values. */ RTDBGAS hAs = DBGFR3AsResolveAndRetain(pUVM, DBGF_AS_KERNEL); RTDBGMOD hMod; int rc = RTDbgAsModuleByName(hAs, "vmlinux", 0, &hMod); if (RT_FAILURE(rc)) return VERR_NOT_FOUND; RTDbgAsRelease(hAs); RTGCPTR GCPtrLogBuf; uint32_t cbLogBuf; uint32_t idxFirst; uint32_t idxNext; struct { void *pvVar; size_t cbHost, cbGuest; const char *pszSymbol; } aSymbols[] = { { &GCPtrLogBuf, sizeof(GCPtrLogBuf), pData->f64Bit ? sizeof(uint64_t) : sizeof(uint32_t), "log_buf" }, { &cbLogBuf, sizeof(cbLogBuf), sizeof(cbLogBuf), "log_buf_len" }, { &idxFirst, sizeof(idxFirst), sizeof(idxFirst), "log_first_idx" }, { &idxNext, sizeof(idxNext), sizeof(idxNext), "log_next_idx" }, }; for (uint32_t i = 0; i < RT_ELEMENTS(aSymbols); i++) { RTDBGSYMBOL SymInfo; rc = RTDbgModSymbolByName(hMod, aSymbols[i].pszSymbol, &SymInfo); if (RT_SUCCESS(rc)) { RT_BZERO(aSymbols[i].pvVar, aSymbols[i].cbHost); Assert(aSymbols[i].cbHost >= aSymbols[i].cbGuest); DBGFADDRESS Addr; rc = DBGFR3MemRead(pUVM, 0 /*idCpu*/, DBGFR3AddrFromFlat(pUVM, &Addr, (RTGCPTR)SymInfo.Value + pData->AddrKernelBase.FlatPtr), aSymbols[i].pvVar, aSymbols[i].cbGuest); if (RT_SUCCESS(rc)) continue; Log(("dbgDiggerLinuxIDmsg_QueryKernelLog: Reading '%s' at %RGv: %Rrc\n", aSymbols[i].pszSymbol, Addr.FlatPtr, rc)); } else Log(("dbgDiggerLinuxIDmsg_QueryKernelLog: Error looking up '%s': %Rrc\n", aSymbols[i].pszSymbol, rc)); RTDbgModRelease(hMod); return VERR_NOT_FOUND; } /* * Check if the values make sense. */ if (pData->f64Bit ? !LNX64_VALID_ADDRESS(GCPtrLogBuf) : !LNX32_VALID_ADDRESS(GCPtrLogBuf)) { Log(("dbgDiggerLinuxIDmsg_QueryKernelLog: 'log_buf' value %RGv is not valid.\n", GCPtrLogBuf)); return VERR_NOT_FOUND; } if ( cbLogBuf < 4096 || !RT_IS_POWER_OF_TWO(cbLogBuf) || cbLogBuf > 16*_1M) { Log(("dbgDiggerLinuxIDmsg_QueryKernelLog: 'log_buf_len' value %#x is not valid.\n", cbLogBuf)); return VERR_NOT_FOUND; } uint32_t const cbLogAlign = 4; if ( idxFirst > cbLogBuf - sizeof(LNXPRINTKHDR) || (idxFirst & (cbLogAlign - 1)) != 0) { Log(("dbgDiggerLinuxIDmsg_QueryKernelLog: 'log_first_idx' value %#x is not valid.\n", idxFirst)); return VERR_NOT_FOUND; } if ( idxNext > cbLogBuf - sizeof(LNXPRINTKHDR) || (idxNext & (cbLogAlign - 1)) != 0) { Log(("dbgDiggerLinuxIDmsg_QueryKernelLog: 'log_next_idx' value %#x is not valid.\n", idxNext)); return VERR_NOT_FOUND; } /* * Read the whole log buffer. */ uint8_t *pbLogBuf = (uint8_t *)RTMemAlloc(cbLogBuf); if (!pbLogBuf) { Log(("dbgDiggerLinuxIDmsg_QueryKernelLog: Failed to allocate %#x bytes for log buffer\n", cbLogBuf)); return VERR_NO_MEMORY; } DBGFADDRESS Addr; rc = DBGFR3MemRead(pUVM, 0 /*idCpu*/, DBGFR3AddrFromFlat(pUVM, &Addr, GCPtrLogBuf), pbLogBuf, cbLogBuf); if (RT_FAILURE(rc)) { Log(("dbgDiggerLinuxIDmsg_QueryKernelLog: Error reading %#x bytes of log buffer at %RGv: %Rrc\n", cbLogBuf, Addr.FlatPtr, rc)); RTMemFree(pbLogBuf); return VERR_NOT_FOUND; } /* * Count the messages in the buffer while doing some basic validation. */ uint32_t const cbUsed = idxFirst == idxNext ? cbLogBuf /* could be empty... */ : idxFirst < idxNext ? idxNext - idxFirst : cbLogBuf - idxFirst + idxNext; uint32_t cbLeft = cbUsed; uint32_t offCur = idxFirst; uint32_t cLogMsgs = 0; while (cbLeft > 0) { PCLNXPRINTKHDR pHdr = (PCLNXPRINTKHDR)&pbLogBuf[offCur]; if (!pHdr->cbTotal) { /* Wrap around packet, most likely... */ if (cbLogBuf - offCur >= cbLeft) break; offCur = 0; pHdr = (PCLNXPRINTKHDR)&pbLogBuf[offCur]; } if (RT_UNLIKELY( pHdr->cbTotal > cbLogBuf - sizeof(*pHdr) - offCur || pHdr->cbTotal > cbLeft || (pHdr->cbTotal & (cbLogAlign - 1)) != 0 || pHdr->cbTotal < (uint32_t)pHdr->cbText + (uint32_t)pHdr->cbDict + sizeof(*pHdr) )) { Log(("dbgDiggerLinuxIDmsg_QueryKernelLog: Invalid printk_log record at %#x: cbTotal=%#x cbText=%#x cbDict=%#x cbLogBuf=%#x cbLeft=%#x\n", offCur, pHdr->cbTotal, pHdr->cbText, pHdr->cbDict, cbLogBuf, cbLeft)); rc = VERR_INVALID_STATE; break; } if (pHdr->cbText > 0) cLogMsgs++; /* next */ offCur += pHdr->cbTotal; cbLeft -= pHdr->cbTotal; } if (RT_FAILURE(rc)) { RTMemFree(pbLogBuf); return rc; } /* * Copy the messages into the output buffer. */ offCur = idxFirst; cbLeft = cbUsed; /* Skip messages that the caller doesn't want. */ if (cMessages < cLogMsgs) { uint32_t cToSkip = cLogMsgs - cMessages; while (cToSkip > 0) { PCLNXPRINTKHDR pHdr = (PCLNXPRINTKHDR)&pbLogBuf[offCur]; if (!pHdr->cbTotal) { offCur = 0; pHdr = (PCLNXPRINTKHDR)&pbLogBuf[offCur]; } if (pHdr->cbText > 0) cToSkip--; /* next */ offCur += pHdr->cbTotal; cbLeft -= pHdr->cbTotal; } } /* Now copy the messages. */ size_t offDst = 0; while (cbLeft > 0) { PCLNXPRINTKHDR pHdr = (PCLNXPRINTKHDR)&pbLogBuf[offCur]; if (!pHdr->cbTotal) { if (cbLogBuf - offCur >= cbLeft) break; offCur = 0; pHdr = (PCLNXPRINTKHDR)&pbLogBuf[offCur]; } if (pHdr->cbText > 0) { char *pchText = (char *)(pHdr + 1); size_t cchText = RTStrNLen(pchText, pHdr->cbText); if (offDst + cchText < cbBuf) { memcpy(&pszBuf[offDst], pHdr + 1, cchText); pszBuf[offDst + cchText] = '\n'; } else if (offDst < cbBuf) memcpy(&pszBuf[offDst], pHdr + 1, cbBuf - offDst); offDst += cchText + 1; } /* next */ offCur += pHdr->cbTotal; cbLeft -= pHdr->cbTotal; } /* Done with the buffer. */ RTMemFree(pbLogBuf); /* Make sure we've reserved a char for the terminator. */ if (!offDst) offDst = 1; /* Set return size value. */ if (pcbActual) *pcbActual = offDst; /* * All VBox strings are UTF-8 and bad things may in theory happen if we * pass bad UTF-8 to code which assumes it's all valid. So, we enforce * UTF-8 upon the guest kernel messages here even if they (probably) have * no defined code set in reality. */ if (offDst <= cbBuf) { pszBuf[offDst - 1] = '\0'; RTStrPurgeEncoding(pszBuf); return VINF_SUCCESS; } if (cbBuf) { pszBuf[cbBuf - 1] = '\0'; RTStrPurgeEncoding(pszBuf); } return VERR_BUFFER_OVERFLOW; }