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/*
* host-signal.h: signal info dependent on the host architecture
*
* Copyright (c) 2003-2005 Fabrice Bellard
* Copyright (c) 2021 Linaro Limited
*
* This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
* See the COPYING file in the top-level directory.
*/
#ifndef AARCH64_HOST_SIGNAL_H
#define AARCH64_HOST_SIGNAL_H
/* The third argument to a SA_SIGINFO handler is ucontext_t. */
typedef ucontext_t host_sigcontext;
/* Pre-3.16 kernel headers don't have these, so provide fallback definitions */
#ifndef ESR_MAGIC
#define ESR_MAGIC 0x45535201
struct esr_context {
struct _aarch64_ctx head;
uint64_t esr;
};
#endif
static inline struct _aarch64_ctx *first_ctx(host_sigcontext *uc)
{
return (struct _aarch64_ctx *)&uc->uc_mcontext.__reserved;
}
static inline struct _aarch64_ctx *next_ctx(struct _aarch64_ctx *hdr)
{
return (struct _aarch64_ctx *)((char *)hdr + hdr->size);
}
static inline uintptr_t host_signal_pc(host_sigcontext *uc)
{
return uc->uc_mcontext.pc;
}
static inline void host_signal_set_pc(host_sigcontext *uc, uintptr_t pc)
{
uc->uc_mcontext.pc = pc;
}
static inline void *host_signal_mask(host_sigcontext *uc)
{
return &uc->uc_sigmask;
}
static inline bool host_signal_write(siginfo_t *info, host_sigcontext *uc)
{
struct _aarch64_ctx *hdr;
uint32_t insn;
/* Find the esr_context, which has the WnR bit in it */
for (hdr = first_ctx(uc); hdr->magic; hdr = next_ctx(hdr)) {
if (hdr->magic == ESR_MAGIC) {
struct esr_context const *ec = (struct esr_context const *)hdr;
uint64_t esr = ec->esr;
/* For data aborts ESR.EC is 0b10010x: then bit 6 is the WnR bit */
return extract32(esr, 27, 5) == 0x12 && extract32(esr, 6, 1) == 1;
}
}
/*
* Fall back to parsing instructions; will only be needed
* for really ancient (pre-3.16) kernels.
*/
insn = *(uint32_t *)host_signal_pc(uc);
return (insn & 0xbfff0000) == 0x0c000000 /* C3.3.1 */
|| (insn & 0xbfe00000) == 0x0c800000 /* C3.3.2 */
|| (insn & 0xbfdf0000) == 0x0d000000 /* C3.3.3 */
|| (insn & 0xbfc00000) == 0x0d800000 /* C3.3.4 */
|| (insn & 0x3f400000) == 0x08000000 /* C3.3.6 */
|| (insn & 0x3bc00000) == 0x39000000 /* C3.3.13 */
|| (insn & 0x3fc00000) == 0x3d800000 /* ... 128bit */
/* Ignore bits 10, 11 & 21, controlling indexing. */
|| (insn & 0x3bc00000) == 0x38000000 /* C3.3.8-12 */
|| (insn & 0x3fe00000) == 0x3c800000 /* ... 128bit */
/* Ignore bits 23 & 24, controlling indexing. */
|| (insn & 0x3a400000) == 0x28000000; /* C3.3.7,14-16 */
}
#endif