zig

sigcontext.h (11368B) - Raw

---

 /* 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 __ASM_SIGCONTEXT_H
 #define __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.
  *
  * Note that the values allocated for use as magic should be chosen to
  * be meaningful in ASCII to aid manual parsing, ZA doesn't follow this
  * convention due to oversight but it should be observed for future additions.
  */
 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;
 };
 
 #define POE_MAGIC	0x504f4530
 
 struct poe_context {
 	struct _aarch64_ctx head;
 	__u64 por_el0;
 };
 
 /*
  * 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 flags;
 	__u16 __reserved[2];
 };
 
 #define SVE_SIG_FLAG_SM	0x1	/* Context describes streaming mode */
 
 /* TPIDR2_EL0 context */
 #define TPIDR2_MAGIC	0x54504902
 
 struct tpidr2_context {
 	struct _aarch64_ctx head;
 	__u64 tpidr2;
 };
 
 /* FPMR context */
 #define FPMR_MAGIC	0x46504d52
 
 struct fpmr_context {
 	struct _aarch64_ctx head;
 	__u64 fpmr;
 };
 
 #define ZA_MAGIC	0x54366345
 
 struct za_context {
 	struct _aarch64_ctx head;
 	__u16 vl;
 	__u16 __reserved[3];
 };
 
 #define ZT_MAGIC	0x5a544e01
 
 struct zt_context {
 	struct _aarch64_ctx head;
 	__u16 nregs;
 	__u16 __reserved[3];
 };
 
 #define GCS_MAGIC	0x47435300
 
 struct gcs_context {
 	struct _aarch64_ctx head;
 	__u64 gcspr;
 	__u64 features_enabled;
 	__u64 reserved;
 };
 
 #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/arch/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.
  *
  * On systems with support for SME the SVE register state may reflect either
  * streaming or non-streaming mode.  In streaming mode the streaming mode
  * vector length will be used and the flag SVE_SIG_FLAG_SM will be set in
  * the flags field. It is permitted to enter or leave streaming mode in
  * a signal return, applications should take care to ensure that any difference
  * in vector length between the two modes is handled, including any resizing
  * and movement of context blocks.
  *
  * Note: for all these macros, the "vq" argument denotes the 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))
 
 /*
  * If the ZA register is enabled for the thread at signal delivery then,
  * za_context.head.size >= ZA_SIG_CONTEXT_SIZE(sve_vq_from_vl(za_context.vl))
  * and the register data may be accessed using the ZA_SIG_*() macros.
  *
  * If za_context.head.size < ZA_SIG_CONTEXT_SIZE(sve_vq_from_vl(za_context.vl))
  * then ZA was not enabled and no register data was included in which case
  * ZA register was not enabled for the thread and no register data
  * the ZA_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 za_context block if it wants to
  * enable the ZA register when it was 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:
  * za_context.vl must equal the thread's current SME vector length when
  * doing a sigreturn.
  */
 
 #define ZA_SIG_REGS_OFFSET					\
 	((sizeof(struct za_context) + (__SVE_VQ_BYTES - 1))	\
 		/ __SVE_VQ_BYTES * __SVE_VQ_BYTES)
 
 #define ZA_SIG_REGS_SIZE(vq) (((vq) * __SVE_VQ_BYTES) * ((vq) * __SVE_VQ_BYTES))
 
 #define ZA_SIG_ZAV_OFFSET(vq, n) (ZA_SIG_REGS_OFFSET + \
 				  (SVE_SIG_ZREG_SIZE(vq) * (n)))
 
 #define ZA_SIG_CONTEXT_SIZE(vq) \
 		(ZA_SIG_REGS_OFFSET + ZA_SIG_REGS_SIZE(vq))
 
 #define ZT_SIG_REG_SIZE 512
 
 #define ZT_SIG_REG_BYTES (ZT_SIG_REG_SIZE / 8)
 
 #define ZT_SIG_REGS_OFFSET sizeof(struct zt_context)
 
 #define ZT_SIG_REGS_SIZE(n) (ZT_SIG_REG_BYTES * (n))
 
 #define ZT_SIG_CONTEXT_SIZE(n) \
 	(sizeof(struct zt_context) + ZT_SIG_REGS_SIZE(n))
 
 #endif /* __ASM_SIGCONTEXT_H */