diff options
Diffstat (limited to 'arch/x86/um/ptrace_32.c')
-rw-r--r-- | arch/x86/um/ptrace_32.c | 273 |
1 files changed, 273 insertions, 0 deletions
diff --git a/arch/x86/um/ptrace_32.c b/arch/x86/um/ptrace_32.c new file mode 100644 index 00000000000..a174fde2531 --- /dev/null +++ b/arch/x86/um/ptrace_32.c @@ -0,0 +1,273 @@ +/* + * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) + * Licensed under the GPL + */ + +#include "linux/mm.h" +#include "linux/sched.h" +#include "asm/uaccess.h" +#include "skas.h" + +extern int arch_switch_tls(struct task_struct *to); + +void arch_switch_to(struct task_struct *to) +{ + int err = arch_switch_tls(to); + if (!err) + return; + + if (err != -EINVAL) + printk(KERN_WARNING "arch_switch_tls failed, errno %d, " + "not EINVAL\n", -err); + else + printk(KERN_WARNING "arch_switch_tls failed, errno = EINVAL\n"); +} + +int is_syscall(unsigned long addr) +{ + unsigned short instr; + int n; + + n = copy_from_user(&instr, (void __user *) addr, sizeof(instr)); + if (n) { + /* access_process_vm() grants access to vsyscall and stub, + * while copy_from_user doesn't. Maybe access_process_vm is + * slow, but that doesn't matter, since it will be called only + * in case of singlestepping, if copy_from_user failed. + */ + n = access_process_vm(current, addr, &instr, sizeof(instr), 0); + if (n != sizeof(instr)) { + printk(KERN_ERR "is_syscall : failed to read " + "instruction from 0x%lx\n", addr); + return 1; + } + } + /* int 0x80 or sysenter */ + return (instr == 0x80cd) || (instr == 0x340f); +} + +/* determines which flags the user has access to. */ +/* 1 = access 0 = no access */ +#define FLAG_MASK 0x00044dd5 + +static const int reg_offsets[] = { + [EBX] = HOST_EBX, + [ECX] = HOST_ECX, + [EDX] = HOST_EDX, + [ESI] = HOST_ESI, + [EDI] = HOST_EDI, + [EBP] = HOST_EBP, + [EAX] = HOST_EAX, + [DS] = HOST_DS, + [ES] = HOST_ES, + [FS] = HOST_FS, + [GS] = HOST_GS, + [EIP] = HOST_IP, + [CS] = HOST_CS, + [EFL] = HOST_EFLAGS, + [UESP] = HOST_SP, + [SS] = HOST_SS, +}; + +int putreg(struct task_struct *child, int regno, unsigned long value) +{ + regno >>= 2; + switch (regno) { + case EBX: + case ECX: + case EDX: + case ESI: + case EDI: + case EBP: + case EAX: + case EIP: + case UESP: + break; + case FS: + if (value && (value & 3) != 3) + return -EIO; + break; + case GS: + if (value && (value & 3) != 3) + return -EIO; + break; + case DS: + case ES: + if (value && (value & 3) != 3) + return -EIO; + value &= 0xffff; + break; + case SS: + case CS: + if ((value & 3) != 3) + return -EIO; + value &= 0xffff; + break; + case EFL: + value &= FLAG_MASK; + child->thread.regs.regs.gp[HOST_EFLAGS] |= value; + return 0; + case ORIG_EAX: + child->thread.regs.regs.syscall = value; + return 0; + default : + panic("Bad register in putreg() : %d\n", regno); + } + child->thread.regs.regs.gp[reg_offsets[regno]] = value; + return 0; +} + +int poke_user(struct task_struct *child, long addr, long data) +{ + if ((addr & 3) || addr < 0) + return -EIO; + + if (addr < MAX_REG_OFFSET) + return putreg(child, addr, data); + else if ((addr >= offsetof(struct user, u_debugreg[0])) && + (addr <= offsetof(struct user, u_debugreg[7]))) { + addr -= offsetof(struct user, u_debugreg[0]); + addr = addr >> 2; + if ((addr == 4) || (addr == 5)) + return -EIO; + child->thread.arch.debugregs[addr] = data; + return 0; + } + return -EIO; +} + +unsigned long getreg(struct task_struct *child, int regno) +{ + unsigned long mask = ~0UL; + + regno >>= 2; + switch (regno) { + case ORIG_EAX: + return child->thread.regs.regs.syscall; + case FS: + case GS: + case DS: + case ES: + case SS: + case CS: + mask = 0xffff; + break; + case EIP: + case UESP: + case EAX: + case EBX: + case ECX: + case EDX: + case ESI: + case EDI: + case EBP: + case EFL: + break; + default: + panic("Bad register in getreg() : %d\n", regno); + } + return mask & child->thread.regs.regs.gp[reg_offsets[regno]]; +} + +/* read the word at location addr in the USER area. */ +int peek_user(struct task_struct *child, long addr, long data) +{ + unsigned long tmp; + + if ((addr & 3) || addr < 0) + return -EIO; + + tmp = 0; /* Default return condition */ + if (addr < MAX_REG_OFFSET) { + tmp = getreg(child, addr); + } + else if ((addr >= offsetof(struct user, u_debugreg[0])) && + (addr <= offsetof(struct user, u_debugreg[7]))) { + addr -= offsetof(struct user, u_debugreg[0]); + addr = addr >> 2; + tmp = child->thread.arch.debugregs[addr]; + } + return put_user(tmp, (unsigned long __user *) data); +} + +static int get_fpregs(struct user_i387_struct __user *buf, struct task_struct *child) +{ + int err, n, cpu = ((struct thread_info *) child->stack)->cpu; + struct user_i387_struct fpregs; + + err = save_fp_registers(userspace_pid[cpu], (unsigned long *) &fpregs); + if (err) + return err; + + n = copy_to_user(buf, &fpregs, sizeof(fpregs)); + if(n > 0) + return -EFAULT; + + return n; +} + +static int set_fpregs(struct user_i387_struct __user *buf, struct task_struct *child) +{ + int n, cpu = ((struct thread_info *) child->stack)->cpu; + struct user_i387_struct fpregs; + + n = copy_from_user(&fpregs, buf, sizeof(fpregs)); + if (n > 0) + return -EFAULT; + + return restore_fp_registers(userspace_pid[cpu], + (unsigned long *) &fpregs); +} + +static int get_fpxregs(struct user_fxsr_struct __user *buf, struct task_struct *child) +{ + int err, n, cpu = ((struct thread_info *) child->stack)->cpu; + struct user_fxsr_struct fpregs; + + err = save_fpx_registers(userspace_pid[cpu], (unsigned long *) &fpregs); + if (err) + return err; + + n = copy_to_user(buf, &fpregs, sizeof(fpregs)); + if(n > 0) + return -EFAULT; + + return n; +} + +static int set_fpxregs(struct user_fxsr_struct __user *buf, struct task_struct *child) +{ + int n, cpu = ((struct thread_info *) child->stack)->cpu; + struct user_fxsr_struct fpregs; + + n = copy_from_user(&fpregs, buf, sizeof(fpregs)); + if (n > 0) + return -EFAULT; + + return restore_fpx_registers(userspace_pid[cpu], + (unsigned long *) &fpregs); +} + +long subarch_ptrace(struct task_struct *child, long request, + unsigned long addr, unsigned long data) +{ + int ret = -EIO; + void __user *datap = (void __user *) data; + switch (request) { + case PTRACE_GETFPREGS: /* Get the child FPU state. */ + ret = get_fpregs(datap, child); + break; + case PTRACE_SETFPREGS: /* Set the child FPU state. */ + ret = set_fpregs(datap, child); + break; + case PTRACE_GETFPXREGS: /* Get the child FPU state. */ + ret = get_fpxregs(datap, child); + break; + case PTRACE_SETFPXREGS: /* Set the child FPU state. */ + ret = set_fpxregs(datap, child); + break; + default: + ret = -EIO; + } + return ret; +} |