/*===- InstrProfilingPlatformAIX.c - Profile data AIX platform ------------===*\ |* |* Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |* See https://llvm.org/LICENSE.txt for license information. |* SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |* \*===----------------------------------------------------------------------===*/ #if defined(_AIX) #ifdef __64BIT__ #define __XCOFF64__ #endif #include <errno.h> #include <stdlib.h> #include <string.h> #include <sys/ldr.h> #include <xcoff.h> #include "InstrProfiling.h" #include "InstrProfilingInternal.h" #define BIN_ID_PREFIX … // If found, write the build-id into the Result buffer. static size_t FindBinaryId(char *Result, size_t Size) { unsigned long EntryAddr = (unsigned long)__builtin_return_address(0); // Use loadquery to get information about loaded modules; loadquery writes // its result into a buffer of unknown size. char Buf[1024]; size_t BufSize = sizeof(Buf); char *BufPtr = Buf; int RC = -1; errno = 0; RC = loadquery(L_GETXINFO | L_IGNOREUNLOAD, BufPtr, (unsigned int)BufSize); if (RC == -1 && errno == ENOMEM) { BufSize = 64000; // should be plenty for any program. BufPtr = malloc(BufSize); if (BufPtr != 0) RC = loadquery(L_GETXINFO | L_IGNOREUNLOAD, BufPtr, (unsigned int)BufSize); } if (RC == -1) goto done; // Locate the ld_xinfo corresponding to this module. struct ld_xinfo *CurInfo = (struct ld_xinfo *)BufPtr; while (1) { unsigned long CurTextStart = (uint64_t)CurInfo->ldinfo_textorg; unsigned long CurTextEnd = CurTextStart + CurInfo->ldinfo_textsize; if (CurTextStart <= EntryAddr && EntryAddr < CurTextEnd) { // Found my slot. Now search for the build-id. char *p = (char *)CurInfo->ldinfo_textorg; FILHDR *f = (FILHDR *)p; AOUTHDR *a = (AOUTHDR *)(p + FILHSZ); SCNHDR *s = (SCNHDR *)(p + FILHSZ + f->f_opthdr + SCNHSZ * (a->o_snloader - 1)); LDHDR *ldhdr = (LDHDR *)(p + s->s_scnptr); // This is the loader string table char *lstr = (char *)ldhdr + ldhdr->l_stoff; // If the build-id exists, it's the first entry. // Each entry is comprised of a 2-byte size component, followed by the // data. size_t len = *(short *)lstr; char *str = (char *)(lstr + 2); size_t PrefixLen = sizeof(BIN_ID_PREFIX) - 1; if (len > PrefixLen && (len - PrefixLen) <= Size && strncmp(str, BIN_ID_PREFIX, PrefixLen) == 0) { memcpy(Result, str + PrefixLen, len - PrefixLen); RC = len - PrefixLen; goto done; } break; } if (CurInfo->ldinfo_next == 0u) break; CurInfo = (struct ld_xinfo *)((char *)CurInfo + CurInfo->ldinfo_next); } done: if (BufSize != sizeof(Buf) && BufPtr != 0) free(BufPtr); return RC; } static int StrToHexError = 0; static uint8_t StrToHex(char c) { if (c >= '0' && c <= '9') return c - '0'; if (c >= 'a' && c <= 'f') return c - 'a' + 0xa; if (c >= 'A' && c <= 'F') return c - 'A' + 0xa; StrToHexError = 1; return 0; } COMPILER_RT_VISIBILITY int __llvm_write_binary_ids(ProfDataWriter *Writer) { // 200 bytes should be enough for the build-id hex string. static char Buf[200]; // Profile reading tools expect this to be 8-bytes long. static int64_t BinaryIdLen = 0; static uint8_t *BinaryIdData = 0; // -1 means we already checked for a BinaryId and didn't find one. if (BinaryIdLen == -1) return 0; // Are we being called for the first time? if (BinaryIdLen == 0) { if (getenv("LLVM_PROFILE_NO_BUILD_ID")) goto fail; int BuildIdLen = FindBinaryId(Buf, sizeof(Buf)); if (BuildIdLen <= 0) goto fail; if (Buf[BuildIdLen - 1] == '\0') BuildIdLen--; // assume even number of digits/chars, so 0xabc must be 0x0abc if ((BuildIdLen % 2) != 0 || BuildIdLen == 0) goto fail; // The numeric ID is represented as an ascii string in the loader section, // so convert it to raw binary. BinaryIdLen = BuildIdLen / 2; BinaryIdData = (uint8_t *)Buf; // Skip "0x" prefix if it exists. if (Buf[0] == '0' && Buf[1] == 'x') { BinaryIdLen -= 1; BinaryIdData += 2; } StrToHexError = 0; for (int i = 0; i < BinaryIdLen; i++) BinaryIdData[i] = (StrToHex(BinaryIdData[2 * i]) << 4) + StrToHex(BinaryIdData[2 * i + 1]); if (StrToHexError) goto fail; if (getenv("LLVM_PROFILE_VERBOSE")) { char *StrBuf = (char *)COMPILER_RT_ALLOCA(2 * BinaryIdLen + 1); for (int i = 0; i < (int)BinaryIdLen; i++) sprintf(&StrBuf[2 * i], "%02x", BinaryIdData[i]); PROF_NOTE("Writing binary id: %s\n", StrBuf); } } uint8_t BinaryIdPadding = __llvm_profile_get_num_padding_bytes(BinaryIdLen); if (Writer && lprofWriteOneBinaryId(Writer, BinaryIdLen, BinaryIdData, BinaryIdPadding) == -1) return -1; // Return -1 rather goto fail to match the NT_GNU_BUILD_ID path. return sizeof(BinaryIdLen) + BinaryIdLen + BinaryIdPadding; fail: if (getenv("LLVM_PROFILE_VERBOSE")) fprintf(stderr, "no or invalid binary id: %.*s\n", (int)sizeof(Buf), Buf); BinaryIdLen = -1; return 0; } // Empty stubs to allow linking object files using the registration-based scheme COMPILER_RT_VISIBILITY void __llvm_profile_register_function(void *Data_) {} COMPILER_RT_VISIBILITY void __llvm_profile_register_names_function(void *NamesStart, uint64_t NamesSize) {} // The __start_SECNAME and __stop_SECNAME symbols (for SECNAME \in // {"__llvm_prf_cnts", "__llvm_prf_data", "__llvm_prf_name", "__llvm_prf_vnds", // "__llvm_prf_vns", "__llvm_prf_vtab"}) // are always live when linking on AIX, regardless if the .o's being linked // reference symbols from the profile library (for example when no files were // compiled with -fprofile-generate). That's because these symbols are kept // alive through references in constructor functions that are always live in the // default linking model on AIX (-bcdtors:all). The __start_SECNAME and // __stop_SECNAME symbols are only resolved by the linker when the SECNAME // section exists. So for the scenario where the user objects have no such // section (i.e. when they are compiled with -fno-profile-generate), we always // define these zero length variables in each of the above 4 sections. static int dummy_cnts[0] COMPILER_RT_SECTION( COMPILER_RT_SEG INSTR_PROF_CNTS_SECT_NAME); static int dummy_bits[0] COMPILER_RT_SECTION( COMPILER_RT_SEG INSTR_PROF_BITS_SECT_NAME); static int dummy_data[0] COMPILER_RT_SECTION( COMPILER_RT_SEG INSTR_PROF_DATA_SECT_NAME); static const int dummy_name[0] COMPILER_RT_SECTION( COMPILER_RT_SEG INSTR_PROF_NAME_SECT_NAME); static int dummy_vnds[0] COMPILER_RT_SECTION( COMPILER_RT_SEG INSTR_PROF_VNODES_SECT_NAME); static int dummy_orderfile[0] COMPILER_RT_SECTION( COMPILER_RT_SEG INSTR_PROF_ORDERFILE_SECT_NAME); static int dummy_vname[0] COMPILER_RT_SECTION( COMPILER_RT_SEG INSTR_PROF_VNAME_SECT_NAME); static int dummy_vtab[0] COMPILER_RT_SECTION( COMPILER_RT_SEG INSTR_PROF_VTAB_SECT_NAME); // To avoid GC'ing of the dummy variables by the linker, reference them in an // array and reference the array in the runtime registration code // (InstrProfilingRuntime.cpp) #ifdef __GNUC__ #pragma GCC diagnostic push #pragma GCC diagnostic ignored "-Wcast-qual" #endif COMPILER_RT_VISIBILITY void *__llvm_profile_keep[] = {(void *)&dummy_cnts, (void *)&dummy_bits, (void *)&dummy_data, (void *)&dummy_name, (void *)&dummy_vnds, (void *)&dummy_orderfile, (void *)&dummy_vname, (void *)&dummy_vtab}; #ifdef __GNUC__ #pragma GCC diagnostic pop #endif #endif
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