uapi/asm/sigcontext.h

1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
7  * hierarchy of CPU and FPU state, available to user-space (on the stack) when
26  * Bytes 464..511 in the current 512-byte layout of the FXSAVE/FXRSTOR frame
33  * last 32-bit word of this extended area (at the
34  * fpstate+extended_size-FP_XSTATE_MAGIC2_SIZE address) is set to
50 	 *  - if magic1 == 0 then it's sizeof(struct _fpstate)
51 	 *  - if magic1 == FP_XSTATE_MAGIC1 then it's sizeof(struct _xstate)
84 /* 10-byte legacy floating point register: */
90 /* 16-byte floating point register: */
97 /* 16-byte XMM register: */
105  * The 32-bit FPU frame:
125 	struct _fpxreg			_fxsr_st[8];	/* FXSR FPU reg data is ignored */
129 		__u32			padding[44];	/* Alias name for old user-space */
139  * The 64-bit FPU frame. (FXSAVE format and later)
152 	/* Note this is not the same as the 32-bit/x87/FSAVE twd: */
200  * The 32-bit signal frame:
236  * The 64-bit signal frame:
289  * The old user-space sigcontext definition, just in case user-space still
291  * field names but otherwise the same layout.
347 	 * Prior to 2.5.64 ("[PATCH] x86-64 updates for 2.5.64-bk3"),
354 	 *  - Some DOSEMU versions stash fs and gs in these slots manually,
358 	 *  - If these slots are ever needed for any other purpose,
359 	 *    there is some risk that very old 64-bit binaries could get
362 	 *    64-bit set_thread_area syscall, so it appears that there
363 	 *    is no TLS API beyond modify_ldt that works in both pre-
364 	 *    and post-2.5.64 kernels.
367 	 * save/restore, it will most likely need to be opt-in and use
374 		__u16			__pad0;	/* Alias name for old (!UC_SIGCONTEXT_SS) user-space */