1 /* SPDX-License-Identifier: GPL-2.0 */
14 	 * NB: 32-bit x86 CPUs are inconsistent as what happens in the
17 	 * - pushl %seg: some do a 16-bit write and leave the high
19 	 * - movl %seg, [mem]: some do a 16-bit write despite the movl
20 	 * - IDT entry: some (e.g. 486) will leave the high bits of CS
23 	 * Fortunately, x86-32 doesn't read the high bits on POP or IRET,
24 	 * so we can just treat all of the segment registers as 16-bit
41 	 * On interrupt, gs and __gsh store the vector number.  They never
49 	unsigned short cs;  member
60 		/* CS selector */
61 	u64	cs	: 16,  member
105 	 * C ABI says these regs are callee-preserved. They aren't saved on
116 	/* These regs are callee-clobbered. Always saved on kernel entry. */
129 	 * - the syscall number (syscall, sysenter, int80)
130 	 * - error_code stored by the CPU on traps and exceptions
131 	 * - the interrupt number for device interrupts
145 		/* CS selector */
146 		u16		cs;  member
147 		/* The extended 64-bit data slot containing CS */
149 		/* The FRED CS extension */
159 		/* The extended 64-bit data slot containing SS */
192 	return regs->ax;  in regs_return_value()
197 	regs->ax = rc;  in regs_set_return_value()
203  * register set was from protected mode with RPL-3 CS value.  This
212 	return ((regs->cs & SEGMENT_RPL_MASK) | (regs->flags & X86_VM_MASK)) >= USER_RPL;  in user_mode()
214 	return !!(regs->cs & 3);  in user_mode()
221 	return (regs->flags & X86_VM_MASK);  in v8086_mode()
232 	 * On non-paravirt systems, this is the only long mode CPL 3  in user_64bit_mode()
235 	return regs->cs == __USER_CS;  in user_64bit_mode()
238 	return regs->cs == __USER_CS || regs->cs == pv_info.extra_user_64bit_cs;  in user_64bit_mode()
247  * 64-bit mode.
259 #define current_user_stack_pointer()	current_pt_regs()->sp
260 #define compat_user_stack_pointer()	current_pt_regs()->sp
264 	bool ret = (regs->ip >= (unsigned long)entry_SYSCALL_64 &&  in ip_within_syscall_gap()
265 		    regs->ip <  (unsigned long)entry_SYSCALL_64_safe_stack);  in ip_within_syscall_gap()
267 	ret = ret || (regs->ip >= (unsigned long)entry_SYSRETQ_unsafe_stack &&  in ip_within_syscall_gap()
268 		      regs->ip <  (unsigned long)entry_SYSRETQ_end);  in ip_within_syscall_gap()
270 	ret = ret || (regs->ip >= (unsigned long)entry_SYSCALL_compat &&  in ip_within_syscall_gap()
271 		      regs->ip <  (unsigned long)entry_SYSCALL_compat_safe_stack);  in ip_within_syscall_gap()
272 	ret = ret || (regs->ip >= (unsigned long)entry_SYSRETL_compat_unsafe_stack &&  in ip_within_syscall_gap()
273 		      regs->ip <  (unsigned long)entry_SYSRETL_compat_end);  in ip_within_syscall_gap()
282 	return regs->sp;  in kernel_stack_pointer()
287 	return regs->ip;  in instruction_pointer()
293 	regs->ip = val;  in instruction_pointer_set()
298 	return regs->bp;  in frame_pointer()
303 	return regs->sp;  in user_stack_pointer()
309 	regs->sp = val;  in user_stack_pointer_set()
314 	return !(regs->flags & X86_EFLAGS_IF);  in regs_irqs_disabled()
323  * regs_get_register() - get register value from its offset
325  * @offset:	offset number of the register.
337 	/* The selector fields are 16-bit. */  in regs_get_register()
338 	if (offset == offsetof(struct pt_regs, cs) ||  in regs_get_register()
352  * regs_within_kernel_stack() - check the address in the stack
362 	return ((addr & ~(THREAD_SIZE - 1)) == (regs->sp & ~(THREAD_SIZE - 1)));  in regs_within_kernel_stack()
366  * regs_get_kernel_stack_nth_addr() - get the address of the Nth entry on stack
368  * @n:		stack entry number.
376 	unsigned long *addr = (unsigned long *)regs->sp;  in regs_get_kernel_stack_nth_addr()
389  * regs_get_kernel_stack_nth() - get Nth entry of the stack
391  * @n:		stack entry number.
414  * regs_get_kernel_argument() - get Nth function argument in kernel
416  * @n:		function argument number (start from 0)
445 		n -= NR_REG_ARGUMENTS - 1;  in regs_get_kernel_argument()