/* * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com) * Licensed under the GPL */ #include #include "linux/sched.h" #include "linux/mm.h" #include "asm/elf.h" #include "asm/ptrace.h" #include "asm/uaccess.h" #include "asm/unistd.h" #include "sysdep/ptrace.h" #include "sysdep/sigcontext.h" #include "sysdep/sc.h" extern int arch_switch_tls(struct task_struct *from, struct task_struct *to); void arch_switch_to(struct task_struct *from, struct task_struct *to) { int err = arch_switch_tls(from, 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("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 int putreg(struct task_struct *child, int regno, unsigned long value) { regno >>= 2; switch (regno) { case FS: if (value && (value & 3) != 3) return -EIO; PT_REGS_FS(&child->thread.regs) = value; return 0; case GS: if (value && (value & 3) != 3) return -EIO; PT_REGS_GS(&child->thread.regs) = value; return 0; 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; value |= PT_REGS_EFLAGS(&child->thread.regs); break; } PT_REGS_SET(&child->thread.regs, 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 retval = ~0UL; regno >>= 2; switch (regno) { case FS: case GS: case DS: case ES: case SS: case CS: retval = 0xffff; /* fall through */ default: retval &= PT_REG(&child->thread.regs, regno); } return retval; } int peek_user(struct task_struct *child, long addr, long data) { /* read the word at location addr in the USER area. */ 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); } struct i387_fxsave_struct { unsigned short cwd; unsigned short swd; unsigned short twd; unsigned short fop; long fip; long fcs; long foo; long fos; long mxcsr; long reserved; long st_space[32]; /* 8*16 bytes for each FP-reg = 128 bytes */ long xmm_space[32]; /* 8*16 bytes for each XMM-reg = 128 bytes */ long padding[56]; }; /* * FPU tag word conversions. */ static inline unsigned short twd_i387_to_fxsr( unsigned short twd ) { unsigned int tmp; /* to avoid 16 bit prefixes in the code */ /* Transform each pair of bits into 01 (valid) or 00 (empty) */ tmp = ~twd; tmp = (tmp | (tmp>>1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */ /* and move the valid bits to the lower byte. */ tmp = (tmp | (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */ tmp = (tmp | (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */ tmp = (tmp | (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */ return tmp; } static inline unsigned long twd_fxsr_to_i387( struct i387_fxsave_struct *fxsave ) { struct _fpxreg *st = NULL; unsigned long twd = (unsigned long) fxsave->twd; unsigned long tag; unsigned long ret = 0xffff0000; int i; #define FPREG_ADDR(f, n) ((char *)&(f)->st_space + (n) * 16); for ( i = 0 ; i < 8 ; i++ ) { if ( twd & 0x1 ) { st = (struct _fpxreg *) FPREG_ADDR( fxsave, i ); switch ( st->exponent & 0x7fff ) { case 0x7fff: tag = 2; /* Special */ break; case 0x0000: if ( !st->significand[0] && !st->significand[1] && !st->significand[2] && !st->significand[3] ) { tag = 1; /* Zero */ } else { tag = 2; /* Special */ } break; default: if ( st->significand[3] & 0x8000 ) { tag = 0; /* Valid */ } else { tag = 2; /* Special */ } break; } } else { tag = 3; /* Empty */ } ret |= (tag << (2 * i)); twd = twd >> 1; } return ret; } static inline int convert_fxsr_to_user(struct _fpstate __user *buf, struct pt_regs *regs) { return 0; } static inline int convert_fxsr_from_user(struct pt_regs *regs, struct _fpstate __user *buf) { return 0; } int get_fpregs(unsigned long buf, struct task_struct *child) { int err; err = convert_fxsr_to_user((struct _fpstate __user *) buf, &child->thread.regs); if(err) return(-EFAULT); else return(0); } int set_fpregs(unsigned long buf, struct task_struct *child) { int err; err = convert_fxsr_from_user(&child->thread.regs, (struct _fpstate __user *) buf); if(err) return(-EFAULT); else return(0); } int get_fpxregs(unsigned long buf, struct task_struct *tsk) { return 0; } int set_fpxregs(unsigned long buf, struct task_struct *tsk) { return 0; } #ifdef notdef int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu) { fpu->cwd = (((SC_FP_CW(PT_REGS_SC(regs)) & 0xffff) << 16) | (SC_FP_SW(PT_REGS_SC(regs)) & 0xffff)); fpu->swd = SC_FP_CSSEL(PT_REGS_SC(regs)) & 0xffff; fpu->twd = SC_FP_IPOFF(PT_REGS_SC(regs)); fpu->fip = SC_FP_CSSEL(PT_REGS_SC(regs)) & 0xffff; fpu->fcs = SC_FP_DATAOFF(PT_REGS_SC(regs)); fpu->foo = SC_FP_DATASEL(PT_REGS_SC(regs)); fpu->fos = 0; memcpy(fpu->st_space, (void *) SC_FP_ST(PT_REGS_SC(regs)), sizeof(fpu->st_space)); return(1); } #endif int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu ) { return 1; } /* * Overrides for Emacs so that we follow Linus's tabbing style. * Emacs will notice this stuff at the end of the file and automatically * adjust the settings for this buffer only. This must remain at the end * of the file. * --------------------------------------------------------------------------- * Local variables: * c-file-style: "linux" * End: */