1 /*Copyright (C) 2015-2020 Free Software Foundation, Inc. 2 3 This file is part of GDB. 4 5 This program is free software; you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by 7 the Free Software Foundation; either version 3 of the License, or 8 (at your option) any later version. 9 10 This program is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 GNU General Public License for more details. 14 15 You should have received a copy of the GNU General Public License 16 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 17 18 #include "gdbsupport/common-defs.h" 19 #include "ppc-linux.h" 20 #include "nat/gdb_ptrace.h" 21 #include <elf.h> 22 23 #ifdef HAVE_GETAUXVAL 24 #include <sys/auxv.h> 25 #endif 26 27 #ifdef __powerpc64__ 28 29 /* Get the HWCAP from the process of GDB or GDBserver. If success, 30 save it in *VALP. */ 31 32 static void 33 ppc64_host_hwcap (unsigned long *valp) 34 { 35 #ifdef HAVE_GETAUXVAL 36 *valp = getauxval (AT_HWCAP); 37 #else 38 unsigned long data[2]; 39 FILE *f = fopen ("/proc/self/auxv", "r"); 40 41 if (f == NULL) 42 return; 43 44 while (fread (data, sizeof (data), 1, f) > 0) 45 { 46 if (data[0] == AT_HWCAP) 47 { 48 *valp = data[1]; 49 break; 50 } 51 } 52 53 fclose (f); 54 #endif /* HAVE_GETAUXVAL */ 55 } 56 57 static inline int 58 ppc64_64bit_inferior_p (long msr) 59 { 60 unsigned long ppc_host_hwcap = 0; 61 62 /* Get host's HWCAP to check whether the machine is Book E. */ 63 ppc64_host_hwcap (&ppc_host_hwcap); 64 65 /* We actually have a 64-bit inferior only if the certain bit of the 66 MSR is set. The PowerISA Book III-S MSR is different from the 67 PowerISA Book III-E MSR. The Book III-S MSR is 64 bits wide, and 68 its MSR[SF] is the bit 0 of a 64-bit value. Book III-E MSR is 32 69 bits wide, and its MSR[CM] is the bit 0 of a 32-bit value. */ 70 if (ppc_host_hwcap & PPC_FEATURE_BOOKE) 71 return msr & 0x80000000; 72 else 73 return msr < 0; 74 } 75 76 #endif 77 78 int 79 ppc_linux_target_wordsize (int tid) 80 { 81 int wordsize = 4; 82 83 /* Check for 64-bit inferior process. This is the case when the host is 84 64-bit, and in addition the top bit of the MSR register is set. */ 85 #ifdef __powerpc64__ 86 long msr; 87 88 errno = 0; 89 msr = (long) ptrace (PTRACE_PEEKUSER, tid, PT_MSR * 8, 0); 90 if (errno == 0 && ppc64_64bit_inferior_p (msr)) 91 wordsize = 8; 92 #endif 93 94 return wordsize; 95 } 96