diff options
Diffstat (limited to 'arch/x86/kernel/i387.c')
| -rw-r--r-- | arch/x86/kernel/i387.c | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c index f2f8540a7f3..7a8a193b514 100644 --- a/arch/x86/kernel/i387.c +++ b/arch/x86/kernel/i387.c @@ -164,6 +164,11 @@ int init_fpu(struct task_struct *tsk) return 0; } +/* + * The xstateregs_active() routine is the same as the fpregs_active() routine, + * as the "regset->n" for the xstate regset will be updated based on the feature + * capabilites supported by the xsave. + */ int fpregs_active(struct task_struct *target, const struct user_regset *regset) { return tsk_used_math(target) ? regset->n : 0; @@ -224,6 +229,84 @@ int xfpregs_set(struct task_struct *target, const struct user_regset *regset, 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) +{ + int ret; + + if (!cpu_has_xsave) + return -ENODEV; + + ret = init_fpu(target); + if (ret) + return ret; + + /* + * First copy the fxsave bytes 0..463. + */ + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, + &target->thread.xstate->xsave, 0, + offsetof(struct user_xstateregs, + i387.xstate_fx_sw)); + if (ret) + return ret; + + /* + * Copy the 48bytes defined by software. + */ + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, + xstate_fx_sw_bytes, + offsetof(struct user_xstateregs, + i387.xstate_fx_sw), + offsetof(struct user_xstateregs, + xsave_hdr)); + if (ret) + return ret; + + /* + * Copy the rest of xstate memory layout. + */ + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, + &target->thread.xstate->xsave.xsave_hdr, + offsetof(struct user_xstateregs, + xsave_hdr), -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) +{ + int ret; + struct xsave_hdr_struct *xsave_hdr; + + if (!cpu_has_xsave) + return -ENODEV; + + ret = init_fpu(target); + if (ret) + return ret; + + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, + &target->thread.xstate->xsave, 0, -1); + + /* + * mxcsr reserved bits must be masked to zero for security reasons. + */ + target->thread.xstate->fxsave.mxcsr &= mxcsr_feature_mask; + + xsave_hdr = &target->thread.xstate->xsave.xsave_hdr; + + xsave_hdr->xstate_bv &= pcntxt_mask; + /* + * These bits must be zero. + */ + xsave_hdr->reserved1[0] = xsave_hdr->reserved1[1] = 0; + + return ret; +} + #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION /* |