/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_PTRACE_H
#define _ASM_X86_PTRACE_H

#include <asm/segment.h>
#include <asm/page_types.h>
#include <uapi/asm/ptrace.h>

#ifndef __ASSEMBLER__
#ifdef __i386__

struct pt_regs {
        /*
         * NB: 32-bit x86 CPUs are inconsistent as what happens in the
         * following cases (where %seg represents a segment register):
         *
         * - pushl %seg: some do a 16-bit write and leave the high
         *   bits alone
         * - movl %seg, [mem]: some do a 16-bit write despite the movl
         * - IDT entry: some (e.g. 486) will leave the high bits of CS
         *   and (if applicable) SS undefined.
         *
         * Fortunately, x86-32 doesn't read the high bits on POP or IRET,
         * so we can just treat all of the segment registers as 16-bit
         * values.
         */
        unsigned long bx;
        unsigned long cx;
        unsigned long dx;
        unsigned long si;
        unsigned long di;
        unsigned long bp;
        unsigned long ax;
        unsigned short ds;
        unsigned short __dsh;
        unsigned short es;
        unsigned short __esh;
        unsigned short fs;
        unsigned short __fsh;
        /*
         * On interrupt, gs and __gsh store the vector number.  They never
         * store gs any more.
         */
        unsigned short gs;
        unsigned short __gsh;
        /* On interrupt, this is the error code. */
        unsigned long orig_ax;
        unsigned long ip;
        unsigned short cs;
        unsigned short __csh;
        unsigned long flags;
        unsigned long sp;
        unsigned short ss;
        unsigned short __ssh;
};

#else /* __i386__ */

struct fred_cs {
                /* CS selector */
        u64     cs      : 16,
                /* Stack level at event time */
                sl      :  2,
                /* IBT in WAIT_FOR_ENDBRANCH state */
                wfe     :  1,
                        : 45;
};

struct fred_ss {
                /* SS selector */
        u64     ss      : 16,
                /* STI state */
                sti     :  1,
                /* Set if syscall, sysenter or INT n */
                swevent :  1,
                /* Event is NMI type */
                nmi     :  1,
                        : 13,
                /* Event vector */
                vector  :  8,
                        :  8,
                /* Event type */
                type    :  4,
                        :  4,
                /* Event was incident to enclave execution */
                enclave :  1,
                /* CPU was in 64-bit mode */
                l       :  1,
                /*
                 * Nested exception during FRED delivery, not set
                 * for #DF.
                 */
                nested  :  1,
                        :  1,
                /*
                 * The length of the instruction causing the event.
                 * Only set for INTO, INT1, INT3, INT n, SYSCALL
                 * and SYSENTER.  0 otherwise.
                 */
                insnlen :  4;
};

struct pt_regs {
        /*
         * C ABI says these regs are callee-preserved. They aren't saved on
         * kernel entry unless syscall needs a complete, fully filled
         * "struct pt_regs".
         */
        unsigned long r15;
        unsigned long r14;
        unsigned long r13;
        unsigned long r12;
        unsigned long bp;
        unsigned long bx;

        /* These regs are callee-clobbered. Always saved on kernel entry. */
        unsigned long r11;
        unsigned long r10;
        unsigned long r9;
        unsigned long r8;
        unsigned long ax;
        unsigned long cx;
        unsigned long dx;
        unsigned long si;
        unsigned long di;

        /*
         * orig_ax is used on entry for:
         * - the syscall number (syscall, sysenter, int80)
         * - error_code stored by the CPU on traps and exceptions
         * - the interrupt number for device interrupts
         *
         * A FRED stack frame starts here:
         *   1) It _always_ includes an error code;
         *
         *   2) The return frame for ERET[US] starts here, but
         *      the content of orig_ax is ignored.
         */
        unsigned long orig_ax;

        /* The IRETQ return frame starts here */
        unsigned long ip;

        union {
                /* CS selector */
                u16             cs;
                /* The extended 64-bit data slot containing CS */
                u64             csx;
                /* The FRED CS extension */
                struct fred_cs  fred_cs;
        };

        unsigned long flags;
        unsigned long sp;

        union {
                /* SS selector */
                u16             ss;
                /* The extended 64-bit data slot containing SS */
                u64             ssx;
                /* The FRED SS extension */
                struct fred_ss  fred_ss;
        };

        /*
         * Top of stack on IDT systems, while FRED systems have extra fields
         * defined above for storing exception related information, e.g. CR2 or
         * DR6.
         */
};

#endif /* !__i386__ */

#ifdef CONFIG_PARAVIRT
#include <asm/paravirt-base.h>
#endif

#include <asm/proto.h>

struct cpuinfo_x86;
struct task_struct;

extern unsigned long profile_pc(struct pt_regs *regs);

extern unsigned long
convert_ip_to_linear(struct task_struct *child, struct pt_regs *regs);
extern void send_sigtrap(struct pt_regs *regs, int error_code, int si_code);


static __always_inline unsigned long regs_return_value(struct pt_regs *regs)
{
        return regs->ax;
}

static __always_inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
{
        regs->ax = rc;
}

/*
 * user_mode(regs) determines whether a register set came from user
 * mode.  On x86_32, this is true if V8086 mode was enabled OR if the
 * register set was from protected mode with RPL-3 CS value.  This
 * tricky test checks that with one comparison.
 *
 * On x86_64, vm86 mode is mercifully nonexistent, and we don't need
 * the extra check.
 */
static __always_inline int user_mode(struct pt_regs *regs)
{
#ifdef CONFIG_X86_32
        return ((regs->cs & SEGMENT_RPL_MASK) | (regs->flags & X86_VM_MASK)) >= USER_RPL;
#else
        return !!(regs->cs & 3);
#endif
}

static __always_inline int v8086_mode(struct pt_regs *regs)
{
#ifdef CONFIG_X86_32
        return (regs->flags & X86_VM_MASK);
#else
        return 0;       /* No V86 mode support in long mode */
#endif
}

static inline bool user_64bit_mode(struct pt_regs *regs)
{
#ifdef CONFIG_X86_64
#ifndef CONFIG_PARAVIRT_XXL
        /*
         * On non-paravirt systems, this is the only long mode CPL 3
         * selector.  We do not allow long mode selectors in the LDT.
         */
        return regs->cs == __USER_CS;
#else
        /* Headers are too twisted for this to go in paravirt.h. */
        return regs->cs == __USER_CS || regs->cs == pv_info.extra_user_64bit_cs;
#endif
#else /* !CONFIG_X86_64 */
        return false;
#endif
}

/*
 * Determine whether the register set came from any context that is running in
 * 64-bit mode.
 */
static inline bool any_64bit_mode(struct pt_regs *regs)
{
#ifdef CONFIG_X86_64
        return !user_mode(regs) || user_64bit_mode(regs);
#else
        return false;
#endif
}

#ifdef CONFIG_X86_64
#define current_user_stack_pointer()    current_pt_regs()->sp
#define compat_user_stack_pointer()     current_pt_regs()->sp

static __always_inline bool ip_within_syscall_gap(struct pt_regs *regs)
{
        bool ret = (regs->ip >= (unsigned long)entry_SYSCALL_64 &&
                    regs->ip <  (unsigned long)entry_SYSCALL_64_safe_stack);

        ret = ret || (regs->ip >= (unsigned long)entry_SYSRETQ_unsafe_stack &&
                      regs->ip <  (unsigned long)entry_SYSRETQ_end);
#ifdef CONFIG_IA32_EMULATION
        ret = ret || (regs->ip >= (unsigned long)entry_SYSCALL_compat &&
                      regs->ip <  (unsigned long)entry_SYSCALL_compat_safe_stack);
        ret = ret || (regs->ip >= (unsigned long)entry_SYSRETL_compat_unsafe_stack &&
                      regs->ip <  (unsigned long)entry_SYSRETL_compat_end);
#endif

        return ret;
}
#endif

static __always_inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
{
        return regs->sp;
}

static __always_inline unsigned long instruction_pointer(struct pt_regs *regs)
{
        return regs->ip;
}

static __always_inline
void instruction_pointer_set(struct pt_regs *regs, unsigned long val)
{
        regs->ip = val;
}

static __always_inline unsigned long frame_pointer(struct pt_regs *regs)
{
        return regs->bp;
}

static __always_inline unsigned long user_stack_pointer(struct pt_regs *regs)
{
        return regs->sp;
}

static __always_inline
void user_stack_pointer_set(struct pt_regs *regs, unsigned long val)
{
        regs->sp = val;
}

static __always_inline bool regs_irqs_disabled(struct pt_regs *regs)
{
        return !(regs->flags & X86_EFLAGS_IF);
}

/* Query offset/name of register from its name/offset */
extern int regs_query_register_offset(const char *name);
extern const char *regs_query_register_name(unsigned int offset);
#define MAX_REG_OFFSET (offsetof(struct pt_regs, ss))

/**
 * regs_get_register() - get register value from its offset
 * @regs:       pt_regs from which register value is gotten.
 * @offset:     offset number of the register.
 *
 * regs_get_register returns the value of a register. The @offset is the
 * offset of the register in struct pt_regs address which specified by @regs.
 * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
 */
static inline unsigned long regs_get_register(struct pt_regs *regs,
                                              unsigned int offset)
{
        if (unlikely(offset > MAX_REG_OFFSET))
                return 0;
#ifdef CONFIG_X86_32
        /* The selector fields are 16-bit. */
        if (offset == offsetof(struct pt_regs, cs) ||
            offset == offsetof(struct pt_regs, ss) ||
            offset == offsetof(struct pt_regs, ds) ||
            offset == offsetof(struct pt_regs, es) ||
            offset == offsetof(struct pt_regs, fs) ||
            offset == offsetof(struct pt_regs, gs)) {
                return *(u16 *)((unsigned long)regs + offset);

        }
#endif
        return *(unsigned long *)((unsigned long)regs + offset);
}

/**
 * regs_within_kernel_stack() - check the address in the stack
 * @regs:       pt_regs which contains kernel stack pointer.
 * @addr:       address which is checked.
 *
 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
 * If @addr is within the kernel stack, it returns true. If not, returns false.
 */
static inline int regs_within_kernel_stack(struct pt_regs *regs,
                                           unsigned long addr)
{
        return ((addr & ~(THREAD_SIZE - 1)) == (regs->sp & ~(THREAD_SIZE - 1)));
}

/**
 * regs_get_kernel_stack_nth_addr() - get the address of the Nth entry on stack
 * @regs:       pt_regs which contains kernel stack pointer.
 * @n:          stack entry number.
 *
 * regs_get_kernel_stack_nth() returns the address of the @n th entry of the
 * kernel stack which is specified by @regs. If the @n th entry is NOT in
 * the kernel stack, this returns NULL.
 */
static inline unsigned long *regs_get_kernel_stack_nth_addr(struct pt_regs *regs, unsigned int n)
{
        unsigned long *addr = (unsigned long *)regs->sp;

        addr += n;
        if (regs_within_kernel_stack(regs, (unsigned long)addr))
                return addr;
        else
                return NULL;
}

/* To avoid include hell, we can't include uaccess.h */
extern long copy_from_kernel_nofault(void *dst, const void *src, size_t size);

/**
 * regs_get_kernel_stack_nth() - get Nth entry of the stack
 * @regs:       pt_regs which contains kernel stack pointer.
 * @n:          stack entry number.
 *
 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
 * is specified by @regs. If the @n th entry is NOT in the kernel stack
 * this returns 0.
 */
static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
                                                      unsigned int n)
{
        unsigned long *addr;
        unsigned long val;
        long ret;

        addr = regs_get_kernel_stack_nth_addr(regs, n);
        if (addr) {
                ret = copy_from_kernel_nofault(&val, addr, sizeof(val));
                if (!ret)
                        return val;
        }
        return 0;
}

/**
 * regs_get_kernel_argument() - get Nth function argument in kernel
 * @regs:       pt_regs of that context
 * @n:          function argument number (start from 0)
 *
 * regs_get_argument() returns @n th argument of the function call.
 * Note that this chooses most probably assignment, in some case
 * it can be incorrect.
 * This is expected to be called from kprobes or ftrace with regs
 * where the top of stack is the return address.
 */
static inline unsigned long regs_get_kernel_argument(struct pt_regs *regs,
                                                     unsigned int n)
{
        static const unsigned int argument_offs[] = {
#ifdef __i386__
                offsetof(struct pt_regs, ax),
                offsetof(struct pt_regs, dx),
                offsetof(struct pt_regs, cx),
#define NR_REG_ARGUMENTS 3
#else
                offsetof(struct pt_regs, di),
                offsetof(struct pt_regs, si),
                offsetof(struct pt_regs, dx),
                offsetof(struct pt_regs, cx),
                offsetof(struct pt_regs, r8),
                offsetof(struct pt_regs, r9),
#define NR_REG_ARGUMENTS 6
#endif
        };

        if (n >= NR_REG_ARGUMENTS) {
                n -= NR_REG_ARGUMENTS - 1;
                return regs_get_kernel_stack_nth(regs, n);
        } else
                return regs_get_register(regs, argument_offs[n]);
}

#define arch_has_single_step()  (1)
#ifdef CONFIG_X86_DEBUGCTLMSR
#define arch_has_block_step()   (1)
#else
#define arch_has_block_step()   (boot_cpu_data.x86 >= 6)
#endif

#define ARCH_HAS_USER_SINGLE_STEP_REPORT

struct user_desc;
extern int do_get_thread_area(struct task_struct *p, int idx,
                              struct user_desc __user *info);
extern int do_set_thread_area(struct task_struct *p, int idx,
                              struct user_desc __user *info, int can_allocate);

#ifdef CONFIG_X86_64
# define do_set_thread_area_64(p, s, t) do_arch_prctl_64(p, s, t)
#else
# define do_set_thread_area_64(p, s, t) (0)
#endif

#endif /* !__ASSEMBLER__ */
#endif /* _ASM_X86_PTRACE_H */