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 AARCH64_HOST_SIGNAL_H 12 #define AARCH64_HOST_SIGNAL_H 13 14 /* Pre-3.16 kernel headers don't have these, so provide fallback definitions */ 15 #ifndef ESR_MAGIC 16 #define ESR_MAGIC 0x45535201 17 struct esr_context { 18 struct _aarch64_ctx head; 19 uint64_t esr; 20 }; 21 #endif 22 23 static inline struct _aarch64_ctx *first_ctx(ucontext_t *uc) 24 { 25 return (struct _aarch64_ctx *)&uc->uc_mcontext.__reserved; 26 } 27 28 static inline struct _aarch64_ctx *next_ctx(struct _aarch64_ctx *hdr) 29 { 30 return (struct _aarch64_ctx *)((char *)hdr + hdr->size); 31 } 32 33 static inline uintptr_t host_signal_pc(ucontext_t *uc) 34 { 35 return uc->uc_mcontext.pc; 36 } 37 38 static inline void host_signal_set_pc(ucontext_t *uc, uintptr_t pc) 39 { 40 uc->uc_mcontext.pc = pc; 41 } 42 43 static inline bool host_signal_write(siginfo_t *info, ucontext_t *uc) 44 { 45 struct _aarch64_ctx *hdr; 46 uint32_t insn; 47 48 /* Find the esr_context, which has the WnR bit in it */ 49 for (hdr = first_ctx(uc); hdr->magic; hdr = next_ctx(hdr)) { 50 if (hdr->magic == ESR_MAGIC) { 51 struct esr_context const *ec = (struct esr_context const *)hdr; 52 uint64_t esr = ec->esr; 53 54 /* For data aborts ESR.EC is 0b10010x: then bit 6 is the WnR bit */ 55 return extract32(esr, 27, 5) == 0x12 && extract32(esr, 6, 1) == 1; 56 } 57 } 58 59 /* 60 * Fall back to parsing instructions; will only be needed 61 * for really ancient (pre-3.16) kernels. 62 */ 63 insn = *(uint32_t *)host_signal_pc(uc); 64 65 return (insn & 0xbfff0000) == 0x0c000000 /* C3.3.1 */ 66 || (insn & 0xbfe00000) == 0x0c800000 /* C3.3.2 */ 67 || (insn & 0xbfdf0000) == 0x0d000000 /* C3.3.3 */ 68 || (insn & 0xbfc00000) == 0x0d800000 /* C3.3.4 */ 69 || (insn & 0x3f400000) == 0x08000000 /* C3.3.6 */ 70 || (insn & 0x3bc00000) == 0x39000000 /* C3.3.13 */ 71 || (insn & 0x3fc00000) == 0x3d800000 /* ... 128bit */ 72 /* Ignore bits 10, 11 & 21, controlling indexing. */ 73 || (insn & 0x3bc00000) == 0x38000000 /* C3.3.8-12 */ 74 || (insn & 0x3fe00000) == 0x3c800000 /* ... 128bit */ 75 /* Ignore bits 23 & 24, controlling indexing. */ 76 || (insn & 0x3a400000) == 0x28000000; /* C3.3.7,14-16 */ 77 } 78 79 #endif 80