--- /dev/null
+/*
+ * FPU register's regset abstraction, for ptrace, core dumps, etc.
+ */
+#include <asm/fpu/internal.h>
+#include <asm/fpu/signal.h>
+#include <asm/fpu/regset.h>
+
+/*
+ * The xstateregs_active() routine is the same as the regset_fpregs_active() routine,
+ * as the "regset->n" for the xstate regset will be updated based on the feature
+ * capabilites supported by the xsave.
+ */
+int regset_fpregs_active(struct task_struct *target, const struct user_regset *regset)
+{
+ struct fpu *target_fpu = &target->thread.fpu;
+
+ return target_fpu->fpstate_active ? regset->n : 0;
+}
+
+int regset_xregset_fpregs_active(struct task_struct *target, const struct user_regset *regset)
+{
+ struct fpu *target_fpu = &target->thread.fpu;
+
+ return (cpu_has_fxsr && target_fpu->fpstate_active) ? regset->n : 0;
+}
+
+int xfpregs_get(struct task_struct *target, const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ void *kbuf, void __user *ubuf)
+{
+ struct fpu *fpu = &target->thread.fpu;
+
+ if (!cpu_has_fxsr)
+ return -ENODEV;
+
+ fpu__activate_fpstate_read(fpu);
+ fpstate_sanitize_xstate(fpu);
+
+ return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ &fpu->state.fxsave, 0, -1);
+}
+
+int xfpregs_set(struct task_struct *target, const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ const void *kbuf, const void __user *ubuf)
+{
+ struct fpu *fpu = &target->thread.fpu;
+ int ret;
+
+ if (!cpu_has_fxsr)
+ return -ENODEV;
+
+ fpu__activate_fpstate_write(fpu);
+ fpstate_sanitize_xstate(fpu);
+
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &fpu->state.fxsave, 0, -1);
+
+ /*
+ * mxcsr reserved bits must be masked to zero for security reasons.
+ */
+ fpu->state.fxsave.mxcsr &= mxcsr_feature_mask;
+
+ /*
+ * update the header bits in the xsave header, indicating the
+ * presence of FP and SSE state.
+ */
+ if (cpu_has_xsave)
+ fpu->state.xsave.header.xfeatures |= XFEATURE_MASK_FPSSE;
+
+ return ret;
+}
+
+int xstateregs_get(struct task_struct *target, const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ void *kbuf, void __user *ubuf)
+{
+ struct fpu *fpu = &target->thread.fpu;
+ struct xregs_state *xsave;
+ int ret;
+
+ if (!cpu_has_xsave)
+ return -ENODEV;
+
+ fpu__activate_fpstate_read(fpu);
+
+ xsave = &fpu->state.xsave;
+
+ /*
+ * Copy the 48bytes defined by the software first into the xstate
+ * memory layout in the thread struct, so that we can copy the entire
+ * xstateregs to the user using one user_regset_copyout().
+ */
+ memcpy(&xsave->i387.sw_reserved,
+ xstate_fx_sw_bytes, sizeof(xstate_fx_sw_bytes));
+ /*
+ * Copy the xstate memory layout.
+ */
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, xsave, 0, -1);
+ return ret;
+}
+
+int xstateregs_set(struct task_struct *target, const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ const void *kbuf, const void __user *ubuf)
+{
+ struct fpu *fpu = &target->thread.fpu;
+ struct xregs_state *xsave;
+ int ret;
+
+ if (!cpu_has_xsave)
+ return -ENODEV;
+
+ fpu__activate_fpstate_write(fpu);
+
+ xsave = &fpu->state.xsave;
+
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, xsave, 0, -1);
+ /*
+ * mxcsr reserved bits must be masked to zero for security reasons.
+ */
+ xsave->i387.mxcsr &= mxcsr_feature_mask;
+ xsave->header.xfeatures &= xfeatures_mask;
+ /*
+ * These bits must be zero.
+ */
+ memset(&xsave->header.reserved, 0, 48);
+
+ return ret;
+}
+
+#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
+
+/*
+ * 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;
+}
+
+#define FPREG_ADDR(f, n) ((void *)&(f)->st_space + (n) * 16)
+#define FP_EXP_TAG_VALID 0
+#define FP_EXP_TAG_ZERO 1
+#define FP_EXP_TAG_SPECIAL 2
+#define FP_EXP_TAG_EMPTY 3
+
+static inline u32 twd_fxsr_to_i387(struct fxregs_state *fxsave)
+{
+ struct _fpxreg *st;
+ u32 tos = (fxsave->swd >> 11) & 7;
+ u32 twd = (unsigned long) fxsave->twd;
+ u32 tag;
+ u32 ret = 0xffff0000u;
+ int i;
+
+ for (i = 0; i < 8; i++, twd >>= 1) {
+ if (twd & 0x1) {
+ st = FPREG_ADDR(fxsave, (i - tos) & 7);
+
+ switch (st->exponent & 0x7fff) {
+ case 0x7fff:
+ tag = FP_EXP_TAG_SPECIAL;
+ break;
+ case 0x0000:
+ if (!st->significand[0] &&
+ !st->significand[1] &&
+ !st->significand[2] &&
+ !st->significand[3])
+ tag = FP_EXP_TAG_ZERO;
+ else
+ tag = FP_EXP_TAG_SPECIAL;
+ break;
+ default:
+ if (st->significand[3] & 0x8000)
+ tag = FP_EXP_TAG_VALID;
+ else
+ tag = FP_EXP_TAG_SPECIAL;
+ break;
+ }
+ } else {
+ tag = FP_EXP_TAG_EMPTY;
+ }
+ ret |= tag << (2 * i);
+ }
+ return ret;
+}
+
+/*
+ * FXSR floating point environment conversions.
+ */
+
+void
+convert_from_fxsr(struct user_i387_ia32_struct *env, struct task_struct *tsk)
+{
+ struct fxregs_state *fxsave = &tsk->thread.fpu.state.fxsave;
+ struct _fpreg *to = (struct _fpreg *) &env->st_space[0];
+ struct _fpxreg *from = (struct _fpxreg *) &fxsave->st_space[0];
+ int i;
+
+ env->cwd = fxsave->cwd | 0xffff0000u;
+ env->swd = fxsave->swd | 0xffff0000u;
+ env->twd = twd_fxsr_to_i387(fxsave);
+
+#ifdef CONFIG_X86_64
+ env->fip = fxsave->rip;
+ env->foo = fxsave->rdp;
+ /*
+ * should be actually ds/cs at fpu exception time, but
+ * that information is not available in 64bit mode.
+ */
+ env->fcs = task_pt_regs(tsk)->cs;
+ if (tsk == current) {
+ savesegment(ds, env->fos);
+ } else {
+ env->fos = tsk->thread.ds;
+ }
+ env->fos |= 0xffff0000;
+#else
+ env->fip = fxsave->fip;
+ env->fcs = (u16) fxsave->fcs | ((u32) fxsave->fop << 16);
+ env->foo = fxsave->foo;
+ env->fos = fxsave->fos;
+#endif
+
+ for (i = 0; i < 8; ++i)
+ memcpy(&to[i], &from[i], sizeof(to[0]));
+}
+
+void convert_to_fxsr(struct task_struct *tsk,
+ const struct user_i387_ia32_struct *env)
+
+{
+ struct fxregs_state *fxsave = &tsk->thread.fpu.state.fxsave;
+ struct _fpreg *from = (struct _fpreg *) &env->st_space[0];
+ struct _fpxreg *to = (struct _fpxreg *) &fxsave->st_space[0];
+ int i;
+
+ fxsave->cwd = env->cwd;
+ fxsave->swd = env->swd;
+ fxsave->twd = twd_i387_to_fxsr(env->twd);
+ fxsave->fop = (u16) ((u32) env->fcs >> 16);
+#ifdef CONFIG_X86_64
+ fxsave->rip = env->fip;
+ fxsave->rdp = env->foo;
+ /* cs and ds ignored */
+#else
+ fxsave->fip = env->fip;
+ fxsave->fcs = (env->fcs & 0xffff);
+ fxsave->foo = env->foo;
+ fxsave->fos = env->fos;
+#endif
+
+ for (i = 0; i < 8; ++i)
+ memcpy(&to[i], &from[i], sizeof(from[0]));
+}
+
+int fpregs_get(struct task_struct *target, const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ void *kbuf, void __user *ubuf)
+{
+ struct fpu *fpu = &target->thread.fpu;
+ struct user_i387_ia32_struct env;
+
+ fpu__activate_fpstate_read(fpu);
+
+ if (!static_cpu_has(X86_FEATURE_FPU))
+ return fpregs_soft_get(target, regset, pos, count, kbuf, ubuf);
+
+ if (!cpu_has_fxsr)
+ return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ &fpu->state.fsave, 0,
+ -1);
+
+ fpstate_sanitize_xstate(fpu);
+
+ if (kbuf && pos == 0 && count == sizeof(env)) {
+ convert_from_fxsr(kbuf, target);
+ return 0;
+ }
+
+ convert_from_fxsr(&env, target);
+
+ return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &env, 0, -1);
+}
+
+int fpregs_set(struct task_struct *target, const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ const void *kbuf, const void __user *ubuf)
+{
+ struct fpu *fpu = &target->thread.fpu;
+ struct user_i387_ia32_struct env;
+ int ret;
+
+ fpu__activate_fpstate_write(fpu);
+ fpstate_sanitize_xstate(fpu);
+
+ if (!static_cpu_has(X86_FEATURE_FPU))
+ return fpregs_soft_set(target, regset, pos, count, kbuf, ubuf);
+
+ if (!cpu_has_fxsr)
+ return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &fpu->state.fsave, 0,
+ -1);
+
+ if (pos > 0 || count < sizeof(env))
+ convert_from_fxsr(&env, target);
+
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &env, 0, -1);
+ if (!ret)
+ convert_to_fxsr(target, &env);
+
+ /*
+ * update the header bit in the xsave header, indicating the
+ * presence of FP.
+ */
+ if (cpu_has_xsave)
+ fpu->state.xsave.header.xfeatures |= XFEATURE_MASK_FP;
+ return ret;
+}
+
+/*
+ * FPU state for core dumps.
+ * This is only used for a.out dumps now.
+ * It is declared generically using elf_fpregset_t (which is
+ * struct user_i387_struct) but is in fact only used for 32-bit
+ * dumps, so on 64-bit it is really struct user_i387_ia32_struct.
+ */
+int dump_fpu(struct pt_regs *regs, struct user_i387_struct *ufpu)
+{
+ struct task_struct *tsk = current;
+ struct fpu *fpu = &tsk->thread.fpu;
+ int fpvalid;
+
+ fpvalid = fpu->fpstate_active;
+ if (fpvalid)
+ fpvalid = !fpregs_get(tsk, NULL,
+ 0, sizeof(struct user_i387_ia32_struct),
+ ufpu, NULL);
+
+ return fpvalid;
+}
+EXPORT_SYMBOL(dump_fpu);
+
+#endif /* CONFIG_X86_32 || CONFIG_IA32_EMULATION */
Code Review / kvmfornfv.git / blobdiff