366 lines
9.8 KiB
C
366 lines
9.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_X86_PTRACE_H
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#define _ASM_X86_PTRACE_H
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#include <asm/segment.h>
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#include <asm/page_types.h>
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#include <uapi/asm/ptrace.h>
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#ifndef __ASSEMBLY__
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#ifdef __i386__
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struct pt_regs {
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/*
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* NB: 32-bit x86 CPUs are inconsistent as what happens in the
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* following cases (where %seg represents a segment register):
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*
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* - pushl %seg: some do a 16-bit write and leave the high
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* bits alone
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* - movl %seg, [mem]: some do a 16-bit write despite the movl
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* - IDT entry: some (e.g. 486) will leave the high bits of CS
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* and (if applicable) SS undefined.
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*
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* Fortunately, x86-32 doesn't read the high bits on POP or IRET,
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* so we can just treat all of the segment registers as 16-bit
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* values.
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*/
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unsigned long bx;
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unsigned long cx;
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unsigned long dx;
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unsigned long si;
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unsigned long di;
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unsigned long bp;
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unsigned long ax;
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unsigned short ds;
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unsigned short __dsh;
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unsigned short es;
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unsigned short __esh;
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unsigned short fs;
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unsigned short __fsh;
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/* On interrupt, gs and __gsh store the vector number. */
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unsigned short gs;
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unsigned short __gsh;
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/* On interrupt, this is the error code. */
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unsigned long orig_ax;
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unsigned long ip;
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unsigned short cs;
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unsigned short __csh;
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unsigned long flags;
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unsigned long sp;
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unsigned short ss;
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unsigned short __ssh;
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};
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#else /* __i386__ */
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struct pt_regs {
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/*
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* C ABI says these regs are callee-preserved. They aren't saved on kernel entry
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* unless syscall needs a complete, fully filled "struct pt_regs".
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*/
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unsigned long r15;
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unsigned long r14;
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unsigned long r13;
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unsigned long r12;
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unsigned long bp;
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unsigned long bx;
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/* These regs are callee-clobbered. Always saved on kernel entry. */
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unsigned long r11;
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unsigned long r10;
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unsigned long r9;
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unsigned long r8;
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unsigned long ax;
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unsigned long cx;
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unsigned long dx;
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unsigned long si;
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unsigned long di;
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/*
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* On syscall entry, this is syscall#. On CPU exception, this is error code.
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* On hw interrupt, it's IRQ number:
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*/
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unsigned long orig_ax;
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/* Return frame for iretq */
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unsigned long ip;
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unsigned long cs;
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unsigned long flags;
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unsigned long sp;
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unsigned long ss;
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/* top of stack page */
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};
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#endif /* !__i386__ */
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#ifdef CONFIG_PARAVIRT
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#include <asm/paravirt_types.h>
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#endif
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struct cpuinfo_x86;
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struct task_struct;
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extern unsigned long profile_pc(struct pt_regs *regs);
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extern unsigned long
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convert_ip_to_linear(struct task_struct *child, struct pt_regs *regs);
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extern void send_sigtrap(struct pt_regs *regs, int error_code, int si_code);
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static inline unsigned long regs_return_value(struct pt_regs *regs)
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{
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return regs->ax;
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}
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static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
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{
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regs->ax = rc;
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}
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/*
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* user_mode(regs) determines whether a register set came from user
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* mode. On x86_32, this is true if V8086 mode was enabled OR if the
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* register set was from protected mode with RPL-3 CS value. This
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* tricky test checks that with one comparison.
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*
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* On x86_64, vm86 mode is mercifully nonexistent, and we don't need
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* the extra check.
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*/
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static inline int user_mode(struct pt_regs *regs)
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{
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#ifdef CONFIG_X86_32
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return ((regs->cs & SEGMENT_RPL_MASK) | (regs->flags & X86_VM_MASK)) >= USER_RPL;
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#else
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return !!(regs->cs & 3);
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#endif
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}
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static inline int v8086_mode(struct pt_regs *regs)
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{
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#ifdef CONFIG_X86_32
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return (regs->flags & X86_VM_MASK);
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#else
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return 0; /* No V86 mode support in long mode */
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#endif
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}
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static inline bool user_64bit_mode(struct pt_regs *regs)
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{
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#ifdef CONFIG_X86_64
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#ifndef CONFIG_PARAVIRT_XXL
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/*
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* On non-paravirt systems, this is the only long mode CPL 3
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* selector. We do not allow long mode selectors in the LDT.
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*/
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return regs->cs == __USER_CS;
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#else
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/* Headers are too twisted for this to go in paravirt.h. */
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return regs->cs == __USER_CS || regs->cs == pv_info.extra_user_64bit_cs;
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#endif
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#else /* !CONFIG_X86_64 */
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return false;
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#endif
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}
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#ifdef CONFIG_X86_64
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#define current_user_stack_pointer() current_pt_regs()->sp
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#define compat_user_stack_pointer() current_pt_regs()->sp
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#endif
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static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
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{
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return regs->sp;
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}
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static inline unsigned long instruction_pointer(struct pt_regs *regs)
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{
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return regs->ip;
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}
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static inline void instruction_pointer_set(struct pt_regs *regs,
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unsigned long val)
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{
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regs->ip = val;
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}
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static inline unsigned long frame_pointer(struct pt_regs *regs)
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{
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return regs->bp;
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}
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static inline unsigned long user_stack_pointer(struct pt_regs *regs)
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{
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return regs->sp;
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}
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static inline void user_stack_pointer_set(struct pt_regs *regs,
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unsigned long val)
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{
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regs->sp = val;
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}
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/* Query offset/name of register from its name/offset */
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extern int regs_query_register_offset(const char *name);
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extern const char *regs_query_register_name(unsigned int offset);
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#define MAX_REG_OFFSET (offsetof(struct pt_regs, ss))
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/**
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* regs_get_register() - get register value from its offset
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* @regs: pt_regs from which register value is gotten.
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* @offset: offset number of the register.
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*
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* regs_get_register returns the value of a register. The @offset is the
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* offset of the register in struct pt_regs address which specified by @regs.
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* If @offset is bigger than MAX_REG_OFFSET, this returns 0.
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*/
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static inline unsigned long regs_get_register(struct pt_regs *regs,
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unsigned int offset)
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{
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if (unlikely(offset > MAX_REG_OFFSET))
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return 0;
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#ifdef CONFIG_X86_32
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/* The selector fields are 16-bit. */
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if (offset == offsetof(struct pt_regs, cs) ||
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offset == offsetof(struct pt_regs, ss) ||
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offset == offsetof(struct pt_regs, ds) ||
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offset == offsetof(struct pt_regs, es) ||
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offset == offsetof(struct pt_regs, fs) ||
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offset == offsetof(struct pt_regs, gs)) {
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return *(u16 *)((unsigned long)regs + offset);
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}
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#endif
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return *(unsigned long *)((unsigned long)regs + offset);
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}
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/**
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* regs_within_kernel_stack() - check the address in the stack
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* @regs: pt_regs which contains kernel stack pointer.
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* @addr: address which is checked.
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*
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* regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
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* If @addr is within the kernel stack, it returns true. If not, returns false.
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*/
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static inline int regs_within_kernel_stack(struct pt_regs *regs,
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unsigned long addr)
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{
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return ((addr & ~(THREAD_SIZE - 1)) == (regs->sp & ~(THREAD_SIZE - 1)));
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}
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/**
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* regs_get_kernel_stack_nth_addr() - get the address of the Nth entry on stack
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* @regs: pt_regs which contains kernel stack pointer.
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* @n: stack entry number.
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*
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* regs_get_kernel_stack_nth() returns the address of the @n th entry of the
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* kernel stack which is specified by @regs. If the @n th entry is NOT in
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* the kernel stack, this returns NULL.
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*/
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static inline unsigned long *regs_get_kernel_stack_nth_addr(struct pt_regs *regs, unsigned int n)
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{
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unsigned long *addr = (unsigned long *)regs->sp;
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addr += n;
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if (regs_within_kernel_stack(regs, (unsigned long)addr))
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return addr;
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else
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return NULL;
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}
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/* To avoid include hell, we can't include uaccess.h */
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extern long probe_kernel_read(void *dst, const void *src, size_t size);
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/**
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* regs_get_kernel_stack_nth() - get Nth entry of the stack
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* @regs: pt_regs which contains kernel stack pointer.
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* @n: stack entry number.
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*
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* regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
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* is specified by @regs. If the @n th entry is NOT in the kernel stack
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* this returns 0.
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*/
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static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
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unsigned int n)
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{
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unsigned long *addr;
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unsigned long val;
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long ret;
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addr = regs_get_kernel_stack_nth_addr(regs, n);
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if (addr) {
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ret = probe_kernel_read(&val, addr, sizeof(val));
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if (!ret)
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return val;
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}
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return 0;
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}
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/**
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* regs_get_kernel_argument() - get Nth function argument in kernel
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* @regs: pt_regs of that context
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* @n: function argument number (start from 0)
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*
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* regs_get_argument() returns @n th argument of the function call.
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* Note that this chooses most probably assignment, in some case
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* it can be incorrect.
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* This is expected to be called from kprobes or ftrace with regs
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* where the top of stack is the return address.
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*/
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static inline unsigned long regs_get_kernel_argument(struct pt_regs *regs,
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unsigned int n)
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{
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static const unsigned int argument_offs[] = {
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#ifdef __i386__
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offsetof(struct pt_regs, ax),
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offsetof(struct pt_regs, cx),
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offsetof(struct pt_regs, dx),
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#define NR_REG_ARGUMENTS 3
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#else
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offsetof(struct pt_regs, di),
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offsetof(struct pt_regs, si),
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offsetof(struct pt_regs, dx),
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offsetof(struct pt_regs, cx),
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offsetof(struct pt_regs, r8),
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offsetof(struct pt_regs, r9),
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#define NR_REG_ARGUMENTS 6
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#endif
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};
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if (n >= NR_REG_ARGUMENTS) {
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n -= NR_REG_ARGUMENTS - 1;
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return regs_get_kernel_stack_nth(regs, n);
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} else
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return regs_get_register(regs, argument_offs[n]);
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}
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#define arch_has_single_step() (1)
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#ifdef CONFIG_X86_DEBUGCTLMSR
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#define arch_has_block_step() (1)
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#else
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#define arch_has_block_step() (boot_cpu_data.x86 >= 6)
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#endif
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#define ARCH_HAS_USER_SINGLE_STEP_REPORT
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/*
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* When hitting ptrace_stop(), we cannot return using SYSRET because
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* that does not restore the full CPU state, only a minimal set. The
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* ptracer can change arbitrary register values, which is usually okay
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* because the usual ptrace stops run off the signal delivery path which
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* forces IRET; however, ptrace_event() stops happen in arbitrary places
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* in the kernel and don't force IRET path.
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*
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* So force IRET path after a ptrace stop.
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*/
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#define arch_ptrace_stop_needed(code, info) \
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({ \
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force_iret(); \
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false; \
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})
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struct user_desc;
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extern int do_get_thread_area(struct task_struct *p, int idx,
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struct user_desc __user *info);
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extern int do_set_thread_area(struct task_struct *p, int idx,
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struct user_desc __user *info, int can_allocate);
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#endif /* !__ASSEMBLY__ */
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#endif /* _ASM_X86_PTRACE_H */
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