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Diffstat (limited to '')
| -rw-r--r-- | arch/arm64/include/uapi/asm/sigcontext.h | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/arch/arm64/include/uapi/asm/sigcontext.h b/arch/arm64/include/uapi/asm/sigcontext.h new file mode 100644 index 000000000..0c796c795 --- /dev/null +++ b/arch/arm64/include/uapi/asm/sigcontext.h @@ -0,0 +1,252 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +/* + * Copyright (C) 2012 ARM Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ +#ifndef _UAPI__ASM_SIGCONTEXT_H +#define _UAPI__ASM_SIGCONTEXT_H + +#ifndef __ASSEMBLY__ + +#include <linux/types.h> + +/* + * Signal context structure - contains all info to do with the state + * before the signal handler was invoked. + */ +struct sigcontext { + __u64 fault_address; + /* AArch64 registers */ + __u64 regs[31]; + __u64 sp; + __u64 pc; + __u64 pstate; + /* 4K reserved for FP/SIMD state and future expansion */ + __u8 __reserved[4096] __attribute__((__aligned__(16))); +}; + +/* + * Allocation of __reserved[]: + * (Note: records do not necessarily occur in the order shown here.) + * + * size description + * + * 0x210 fpsimd_context + * 0x10 esr_context + * 0x8a0 sve_context (vl <= 64) (optional) + * 0x20 extra_context (optional) + * 0x10 terminator (null _aarch64_ctx) + * + * 0x510 (reserved for future allocation) + * + * New records that can exceed this space need to be opt-in for userspace, so + * that an expanded signal frame is not generated unexpectedly. The mechanism + * for opting in will depend on the extension that generates each new record. + * The above table documents the maximum set and sizes of records than can be + * generated when userspace does not opt in for any such extension. + */ + +/* + * Header to be used at the beginning of structures extending the user + * context. Such structures must be placed after the rt_sigframe on the stack + * and be 16-byte aligned. The last structure must be a dummy one with the + * magic and size set to 0. + */ +struct _aarch64_ctx { + __u32 magic; + __u32 size; +}; + +#define FPSIMD_MAGIC 0x46508001 + +struct fpsimd_context { + struct _aarch64_ctx head; + __u32 fpsr; + __u32 fpcr; + __uint128_t vregs[32]; +}; + +/* + * Note: similarly to all other integer fields, each V-register is stored in an + * endianness-dependent format, with the byte at offset i from the start of the + * in-memory representation of the register value containing + * + * bits [(7 + 8 * i) : (8 * i)] of the register on little-endian hosts; or + * bits [(127 - 8 * i) : (120 - 8 * i)] on big-endian hosts. + */ + +/* ESR_EL1 context */ +#define ESR_MAGIC 0x45535201 + +struct esr_context { + struct _aarch64_ctx head; + __u64 esr; +}; + +/* + * extra_context: describes extra space in the signal frame for + * additional structures that don't fit in sigcontext.__reserved[]. + * + * Note: + * + * 1) fpsimd_context, esr_context and extra_context must be placed in + * sigcontext.__reserved[] if present. They cannot be placed in the + * extra space. Any other record can be placed either in the extra + * space or in sigcontext.__reserved[], unless otherwise specified in + * this file. + * + * 2) There must not be more than one extra_context. + * + * 3) If extra_context is present, it must be followed immediately in + * sigcontext.__reserved[] by the terminating null _aarch64_ctx. + * + * 4) The extra space to which datap points must start at the first + * 16-byte aligned address immediately after the terminating null + * _aarch64_ctx that follows the extra_context structure in + * __reserved[]. The extra space may overrun the end of __reserved[], + * as indicated by a sufficiently large value for the size field. + * + * 5) The extra space must itself be terminated with a null + * _aarch64_ctx. + */ +#define EXTRA_MAGIC 0x45585401 + +struct extra_context { + struct _aarch64_ctx head; + __u64 datap; /* 16-byte aligned pointer to extra space cast to __u64 */ + __u32 size; /* size in bytes of the extra space */ + __u32 __reserved[3]; +}; + +#define SVE_MAGIC 0x53564501 + +struct sve_context { + struct _aarch64_ctx head; + __u16 vl; + __u16 __reserved[3]; +}; + +#endif /* !__ASSEMBLY__ */ + +#include <asm/sve_context.h> + +/* + * The SVE architecture leaves space for future expansion of the + * vector length beyond its initial architectural limit of 2048 bits + * (16 quadwords). + * + * See linux/Documentation/arm64/sve.rst for a description of the VL/VQ + * terminology. + */ +#define SVE_VQ_BYTES __SVE_VQ_BYTES /* bytes per quadword */ + +#define SVE_VQ_MIN __SVE_VQ_MIN +#define SVE_VQ_MAX __SVE_VQ_MAX + +#define SVE_VL_MIN __SVE_VL_MIN +#define SVE_VL_MAX __SVE_VL_MAX + +#define SVE_NUM_ZREGS __SVE_NUM_ZREGS +#define SVE_NUM_PREGS __SVE_NUM_PREGS + +#define sve_vl_valid(vl) __sve_vl_valid(vl) +#define sve_vq_from_vl(vl) __sve_vq_from_vl(vl) +#define sve_vl_from_vq(vq) __sve_vl_from_vq(vq) + +/* + * If the SVE registers are currently live for the thread at signal delivery, + * sve_context.head.size >= + * SVE_SIG_CONTEXT_SIZE(sve_vq_from_vl(sve_context.vl)) + * and the register data may be accessed using the SVE_SIG_*() macros. + * + * If sve_context.head.size < + * SVE_SIG_CONTEXT_SIZE(sve_vq_from_vl(sve_context.vl)), + * the SVE registers were not live for the thread and no register data + * is included: in this case, the SVE_SIG_*() macros should not be + * used except for this check. + * + * The same convention applies when returning from a signal: a caller + * will need to remove or resize the sve_context block if it wants to + * make the SVE registers live when they were previously non-live or + * vice-versa. This may require the caller to allocate fresh + * memory and/or move other context blocks in the signal frame. + * + * Changing the vector length during signal return is not permitted: + * sve_context.vl must equal the thread's current vector length when + * doing a sigreturn. + * + * + * Note: for all these macros, the "vq" argument denotes the SVE + * vector length in quadwords (i.e., units of 128 bits). + * + * The correct way to obtain vq is to use sve_vq_from_vl(vl). The + * result is valid if and only if sve_vl_valid(vl) is true. This is + * guaranteed for a struct sve_context written by the kernel. + * + * + * Additional macros describe the contents and layout of the payload. + * For each, SVE_SIG_x_OFFSET(args) is the start offset relative to + * the start of struct sve_context, and SVE_SIG_x_SIZE(args) is the + * size in bytes: + * + * x type description + * - ---- ----------- + * REGS the entire SVE context + * + * ZREGS __uint128_t[SVE_NUM_ZREGS][vq] all Z-registers + * ZREG __uint128_t[vq] individual Z-register Zn + * + * PREGS uint16_t[SVE_NUM_PREGS][vq] all P-registers + * PREG uint16_t[vq] individual P-register Pn + * + * FFR uint16_t[vq] first-fault status register + * + * Additional data might be appended in the future. + * + * Unlike vregs[] in fpsimd_context, each SVE scalable register (Z-, P- or FFR) + * is encoded in memory in an endianness-invariant format, with the byte at + * offset i from the start of the in-memory representation containing bits + * [(7 + 8 * i) : (8 * i)] of the register value. + */ + +#define SVE_SIG_ZREG_SIZE(vq) __SVE_ZREG_SIZE(vq) +#define SVE_SIG_PREG_SIZE(vq) __SVE_PREG_SIZE(vq) +#define SVE_SIG_FFR_SIZE(vq) __SVE_FFR_SIZE(vq) + +#define SVE_SIG_REGS_OFFSET \ + ((sizeof(struct sve_context) + (__SVE_VQ_BYTES - 1)) \ + / __SVE_VQ_BYTES * __SVE_VQ_BYTES) + +#define SVE_SIG_ZREGS_OFFSET \ + (SVE_SIG_REGS_OFFSET + __SVE_ZREGS_OFFSET) +#define SVE_SIG_ZREG_OFFSET(vq, n) \ + (SVE_SIG_REGS_OFFSET + __SVE_ZREG_OFFSET(vq, n)) +#define SVE_SIG_ZREGS_SIZE(vq) __SVE_ZREGS_SIZE(vq) + +#define SVE_SIG_PREGS_OFFSET(vq) \ + (SVE_SIG_REGS_OFFSET + __SVE_PREGS_OFFSET(vq)) +#define SVE_SIG_PREG_OFFSET(vq, n) \ + (SVE_SIG_REGS_OFFSET + __SVE_PREG_OFFSET(vq, n)) +#define SVE_SIG_PREGS_SIZE(vq) __SVE_PREGS_SIZE(vq) + +#define SVE_SIG_FFR_OFFSET(vq) \ + (SVE_SIG_REGS_OFFSET + __SVE_FFR_OFFSET(vq)) + +#define SVE_SIG_REGS_SIZE(vq) \ + (__SVE_FFR_OFFSET(vq) + __SVE_FFR_SIZE(vq)) + +#define SVE_SIG_CONTEXT_SIZE(vq) \ + (SVE_SIG_REGS_OFFSET + SVE_SIG_REGS_SIZE(vq)) + +#endif /* _UAPI__ASM_SIGCONTEXT_H */ |