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Diffstat (limited to 'arch/x86/include/asm/ptrace.h')
| -rw-r--r-- | arch/x86/include/asm/ptrace.h | 395 |
1 files changed, 395 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..f4db78b09 --- /dev/null +++ b/arch/x86/include/asm/ptrace.h @@ -0,0 +1,395 @@ +/* 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; + /* + * 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 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 + +#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 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 __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 inline unsigned long kernel_stack_pointer(struct pt_regs *regs) +{ + return regs->sp; +} + +static inline unsigned long instruction_pointer(struct pt_regs *regs) +{ + return regs->ip; +} + +static inline void instruction_pointer_set(struct pt_regs *regs, + unsigned long val) +{ + regs->ip = val; +} + +static inline unsigned long frame_pointer(struct pt_regs *regs) +{ + return regs->bp; +} + +static inline unsigned long user_stack_pointer(struct pt_regs *regs) +{ + return regs->sp; +} + +static 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 /* !__ASSEMBLY__ */ +#endif /* _ASM_X86_PTRACE_H */ |