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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Macros for Flexible Return and Event Delivery (FRED)
*/
#ifndef ASM_X86_FRED_H
#define ASM_X86_FRED_H
#include <linux/const.h>
#include <asm/asm.h>
#include <asm/trapnr.h>
/*
* FRED event return instruction opcodes for ERET{S,U}; supported in
* binutils >= 2.41.
*/
#define ERETS _ASM_BYTES(0xf2,0x0f,0x01,0xca)
#define ERETU _ASM_BYTES(0xf3,0x0f,0x01,0xca)
/*
* RSP is aligned to a 64-byte boundary before used to push a new stack frame
*/
#define FRED_STACK_FRAME_RSP_MASK _AT(unsigned long, (~0x3f))
/*
* Used for the return address for call emulation during code patching,
* and measured in 64-byte cache lines.
*/
#define FRED_CONFIG_REDZONE_AMOUNT 1
#define FRED_CONFIG_REDZONE (_AT(unsigned long, FRED_CONFIG_REDZONE_AMOUNT) << 6)
#define FRED_CONFIG_INT_STKLVL(l) (_AT(unsigned long, l) << 9)
#define FRED_CONFIG_ENTRYPOINT(p) _AT(unsigned long, (p))
#ifndef __ASSEMBLY__
#ifdef CONFIG_X86_FRED
#include <linux/kernel.h>
#include <linux/sched/task_stack.h>
#include <asm/ptrace.h>
struct fred_info {
/* Event data: CR2, DR6, ... */
unsigned long edata;
unsigned long resv;
};
/* Full format of the FRED stack frame */
struct fred_frame {
struct pt_regs regs;
struct fred_info info;
};
static __always_inline struct fred_info *fred_info(struct pt_regs *regs)
{
return &container_of(regs, struct fred_frame, regs)->info;
}
static __always_inline unsigned long fred_event_data(struct pt_regs *regs)
{
return fred_info(regs)->edata;
}
void asm_fred_entrypoint_user(void);
void asm_fred_entrypoint_kernel(void);
void asm_fred_entry_from_kvm(struct fred_ss);
__visible void fred_entry_from_user(struct pt_regs *regs);
__visible void fred_entry_from_kernel(struct pt_regs *regs);
__visible void __fred_entry_from_kvm(struct pt_regs *regs);
/* Can be called from noinstr code, thus __always_inline */
static __always_inline void fred_entry_from_kvm(unsigned int type, unsigned int vector)
{
struct fred_ss ss = {
.ss =__KERNEL_DS,
.type = type,
.vector = vector,
.nmi = type == EVENT_TYPE_NMI,
.lm = 1,
};
asm_fred_entry_from_kvm(ss);
}
void cpu_init_fred_exceptions(void);
void cpu_init_fred_rsps(void);
void fred_complete_exception_setup(void);
DECLARE_PER_CPU(unsigned long, fred_rsp0);
static __always_inline void fred_sync_rsp0(unsigned long rsp0)
{
__this_cpu_write(fred_rsp0, rsp0);
}
static __always_inline void fred_update_rsp0(void)
{
unsigned long rsp0 = (unsigned long) task_stack_page(current) + THREAD_SIZE;
if (cpu_feature_enabled(X86_FEATURE_FRED) && (__this_cpu_read(fred_rsp0) != rsp0)) {
wrmsrns(MSR_IA32_FRED_RSP0, rsp0);
__this_cpu_write(fred_rsp0, rsp0);
}
}
#else /* CONFIG_X86_FRED */
static __always_inline unsigned long fred_event_data(struct pt_regs *regs) { return 0; }
static inline void cpu_init_fred_exceptions(void) { }
static inline void cpu_init_fred_rsps(void) { }
static inline void fred_complete_exception_setup(void) { }
static inline void fred_entry_from_kvm(unsigned int type, unsigned int vector) { }
static inline void fred_sync_rsp0(unsigned long rsp0) { }
static inline void fred_update_rsp0(void) { }
#endif /* CONFIG_X86_FRED */
#endif /* !__ASSEMBLY__ */
#endif /* ASM_X86_FRED_H */
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