6 // glibc lies about the contents of the fpstate the kernel provides, hiding the FXSR
9 /* Regular FPU environment */
15 unsigned long dataoff;
16 unsigned long datasel;
18 unsigned short status;
19 unsigned short magic; /* 0xffff = regular FPU data only */
21 /* FXSR FPU environment */
22 unsigned long _fxsr_env[6]; /* FXSR FPU env is ignored */
24 unsigned long reserved;
25 struct _fpxreg _fxsr_st[8]; /* FXSR FPU reg data is ignored */
26 struct _xmmreg _xmm[8];
27 unsigned long padding[56];
30 #define X86_FXSR_MAGIC 0x0000
32 inline static void *ucontext_stack_pointer(void *uap)
34 ucontext_t *ucontext = (ucontext_t *)uap;
35 return (void *)ucontext->uc_mcontext.gregs[7];
38 inline static unsigned int uap_fpu_status(void *uap)
40 ucontext_t *ucontext = (ucontext_t *)uap;
41 struct _fpstate *fpregs = (struct _fpstate *)ucontext->uc_mcontext.fpregs;
42 if (fpregs->magic == X86_FXSR_MAGIC)
43 return fpregs->sw | fpregs->mxcsr;
48 inline static void uap_clear_fpu_status(void *uap)
50 ucontext_t *ucontext = (ucontext_t *)uap;
51 struct _fpstate *fpregs = (struct _fpstate *)ucontext->uc_mcontext.fpregs;
53 if (fpregs->magic == X86_FXSR_MAGIC)
54 fpregs->mxcsr &= 0xffffffc0;
57 #define UAP_PROGRAM_COUNTER(ucontext) \
58 (((ucontext_t *)(ucontext))->uc_mcontext.gregs[14])