| /* 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 __ASSEMBLY__ |
| #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; |
| unsigned short gs; |
| unsigned short __gsh; |
| 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 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; |
| /* |
| * On syscall entry, this is syscall#. On CPU exception, this is error code. |
| * On hw interrupt, it's IRQ number: |
| */ |
| unsigned long orig_ax; |
| /* Return frame for iretq */ |
| unsigned long ip; |
| unsigned long cs; |
| unsigned long flags; |
| unsigned long sp; |
| unsigned long ss; |
| /* top of stack page */ |
| }; |
| |
| #endif /* !__i386__ */ |
| |
| #ifdef CONFIG_PARAVIRT |
| #include <asm/paravirt_types.h> |
| #endif |
| |
| struct cpuinfo_x86; |
| struct task_struct; |
| |
| extern unsigned long profile_pc(struct pt_regs *regs); |
| #define profile_pc profile_pc |
| |
| extern unsigned long |
| convert_ip_to_linear(struct task_struct *child, struct pt_regs *regs); |
| extern void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, |
| int error_code, int si_code); |
| |
| |
| static inline unsigned long regs_return_value(struct pt_regs *regs) |
| { |
| return regs->ax; |
| } |
| |
| static 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 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 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 |
| /* |
| * 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 |
| } |
| |
| #ifdef CONFIG_X86_64 |
| #define current_user_stack_pointer() current_pt_regs()->sp |
| #define compat_user_stack_pointer() current_pt_regs()->sp |
| #endif |
| |
| #ifdef CONFIG_X86_32 |
| extern unsigned long kernel_stack_pointer(struct pt_regs *regs); |
| #else |
| static inline unsigned long kernel_stack_pointer(struct pt_regs *regs) |
| { |
| return regs->sp; |
| } |
| #endif |
| |
| #define GET_IP(regs) ((regs)->ip) |
| #define GET_FP(regs) ((regs)->bp) |
| #define GET_USP(regs) ((regs)->sp) |
| |
| #include <asm-generic/ptrace.h> |
| |
| /* 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 |
| /* |
| * Traps from the kernel do not save sp and ss. |
| * Use the helper function to retrieve sp. |
| */ |
| if (offset == offsetof(struct pt_regs, sp) && |
| regs->cs == __KERNEL_CS) |
| return kernel_stack_pointer(regs); |
| |
| /* 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)) == |
| (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))); |
| } |
| |
| /** |
| * 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 *)kernel_stack_pointer(regs); |
| addr += n; |
| if (regs_within_kernel_stack(regs, (unsigned long)addr)) |
| return *addr; |
| else |
| 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, cx), |
| offsetof(struct pt_regs, dx), |
| #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_INFO |
| |
| /* |
| * When hitting ptrace_stop(), we cannot return using SYSRET because |
| * that does not restore the full CPU state, only a minimal set. The |
| * ptracer can change arbitrary register values, which is usually okay |
| * because the usual ptrace stops run off the signal delivery path which |
| * forces IRET; however, ptrace_event() stops happen in arbitrary places |
| * in the kernel and don't force IRET path. |
| * |
| * So force IRET path after a ptrace stop. |
| */ |
| #define arch_ptrace_stop_needed(code, info) \ |
| ({ \ |
| force_iret(); \ |
| false; \ |
| }) |
| |
| 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); |
| |
| #endif /* !__ASSEMBLY__ */ |
| #endif /* _ASM_X86_PTRACE_H */ |