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Diffstat (limited to 'arch/x86/include/asm/ptrace.h')
| -rw-r--r-- | arch/x86/include/asm/ptrace.h | 319 |
1 files changed, 319 insertions, 0 deletions
diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h new file mode 100644 index 000000000..ee696efec --- /dev/null +++ b/arch/x86/include/asm/ptrace.h @@ -0,0 +1,319 @@ +/* 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_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 *)kernel_stack_pointer(regs); + + 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 probe_kernel_read(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 = probe_kernel_read(&val, addr, sizeof(val)); + if (!ret) + return val; + } + return 0; +} + +#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 */ |