1 /* 2 * host-signal.h: signal info dependent on the host architecture 3 * 4 * Copyright (c) 2003-2005 Fabrice Bellard 5 * Copyright (c) 2021 Linaro Limited 6 * 7 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later. 8 * See the COPYING file in the top-level directory. 9 */ 10 11 #ifndef S390_HOST_SIGNAL_H 12 #define S390_HOST_SIGNAL_H 13 14 /* The third argument to a SA_SIGINFO handler is ucontext_t. */ 15 typedef ucontext_t host_sigcontext; 16 17 static inline uintptr_t host_signal_pc(host_sigcontext *uc) 18 { 19 return uc->uc_mcontext.psw.addr; 20 } 21 22 static inline void host_signal_set_pc(host_sigcontext *uc, uintptr_t pc) 23 { 24 uc->uc_mcontext.psw.addr = pc; 25 } 26 27 static inline void *host_signal_mask(host_sigcontext *uc) 28 { 29 return &uc->uc_sigmask; 30 } 31 32 static inline bool host_signal_write(siginfo_t *info, host_sigcontext *uc) 33 { 34 uint16_t *pinsn = (uint16_t *)host_signal_pc(uc); 35 36 /* 37 * ??? On linux, the non-rt signal handler has 4 (!) arguments instead 38 * of the normal 2 arguments. The 4th argument contains the "Translation- 39 * Exception Identification for DAT Exceptions" from the hardware (aka 40 * "int_parm_long"), which does in fact contain the is_write value. 41 * The rt signal handler, as far as I can tell, does not give this value 42 * at all. Not that we could get to it from here even if it were. 43 * So fall back to parsing instructions. Treat read-modify-write ones as 44 * writes, which is not fully correct, but for tracking self-modifying code 45 * this is better than treating them as reads. Checking si_addr page flags 46 * might be a viable improvement, albeit a racy one. 47 */ 48 /* ??? This is not even close to complete. */ 49 switch (pinsn[0] >> 8) { 50 case 0x50: /* ST */ 51 case 0x42: /* STC */ 52 case 0x40: /* STH */ 53 case 0x44: /* EX */ 54 case 0xba: /* CS */ 55 case 0xbb: /* CDS */ 56 return true; 57 case 0xc4: /* RIL format insns */ 58 switch (pinsn[0] & 0xf) { 59 case 0xf: /* STRL */ 60 case 0xb: /* STGRL */ 61 case 0x7: /* STHRL */ 62 return true; 63 } 64 break; 65 case 0xc6: /* RIL-b format insns */ 66 switch (pinsn[0] & 0xf) { 67 case 0x0: /* EXRL */ 68 return true; 69 } 70 break; 71 case 0xc8: /* SSF format insns */ 72 switch (pinsn[0] & 0xf) { 73 case 0x2: /* CSST */ 74 return true; 75 } 76 break; 77 case 0xe3: /* RXY format insns */ 78 switch (pinsn[2] & 0xff) { 79 case 0x50: /* STY */ 80 case 0x24: /* STG */ 81 case 0x72: /* STCY */ 82 case 0x70: /* STHY */ 83 case 0x8e: /* STPQ */ 84 case 0x3f: /* STRVH */ 85 case 0x3e: /* STRV */ 86 case 0x2f: /* STRVG */ 87 return true; 88 } 89 break; 90 case 0xe6: 91 switch (pinsn[2] & 0xff) { 92 case 0x09: /* VSTEBRH */ 93 case 0x0a: /* VSTEBRG */ 94 case 0x0b: /* VSTEBRF */ 95 case 0x0e: /* VSTBR */ 96 case 0x0f: /* VSTER */ 97 case 0x3f: /* VSTRLR */ 98 return true; 99 } 100 break; 101 case 0xe7: 102 switch (pinsn[2] & 0xff) { 103 case 0x08: /* VSTEB */ 104 case 0x09: /* VSTEH */ 105 case 0x0a: /* VSTEG */ 106 case 0x0b: /* VSTEF */ 107 case 0x0e: /* VST */ 108 case 0x1a: /* VSCEG */ 109 case 0x1b: /* VSCEF */ 110 case 0x3e: /* VSTM */ 111 case 0x3f: /* VSTL */ 112 return true; 113 } 114 break; 115 case 0xeb: /* RSY format insns */ 116 switch (pinsn[2] & 0xff) { 117 case 0x14: /* CSY */ 118 case 0x30: /* CSG */ 119 case 0x31: /* CDSY */ 120 case 0x3e: /* CDSG */ 121 case 0xe4: /* LANG */ 122 case 0xe6: /* LAOG */ 123 case 0xe7: /* LAXG */ 124 case 0xe8: /* LAAG */ 125 case 0xea: /* LAALG */ 126 case 0xf4: /* LAN */ 127 case 0xf6: /* LAO */ 128 case 0xf7: /* LAX */ 129 case 0xfa: /* LAAL */ 130 case 0xf8: /* LAA */ 131 return true; 132 } 133 break; 134 } 135 return false; 136 } 137 138 #endif 139