61 lines
1.5 KiB
C++
61 lines
1.5 KiB
C++
#include <ucontext.h>
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namespace factor
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{
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// glibc lies about the contents of the fpstate the kernel provides, hiding the FXSR
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// environment
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struct _fpstate {
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/* Regular FPU environment */
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unsigned long cw;
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unsigned long sw;
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unsigned long tag;
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unsigned long ipoff;
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unsigned long cssel;
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unsigned long dataoff;
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unsigned long datasel;
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struct _fpreg _st[8];
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unsigned short status;
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unsigned short magic; /* 0xffff = regular FPU data only */
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/* FXSR FPU environment */
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unsigned long _fxsr_env[6]; /* FXSR FPU env is ignored */
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unsigned long mxcsr;
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unsigned long reserved;
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struct _fpxreg _fxsr_st[8]; /* FXSR FPU reg data is ignored */
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struct _xmmreg _xmm[8];
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unsigned long padding[56];
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};
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#define X86_FXSR_MAGIC 0x0000
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inline static void *ucontext_stack_pointer(void *uap)
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{
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ucontext_t *ucontext = (ucontext_t *)uap;
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return (void *)ucontext->uc_mcontext.gregs[7];
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}
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inline static unsigned int uap_fpu_status(void *uap)
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{
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ucontext_t *ucontext = (ucontext_t *)uap;
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struct _fpstate *fpregs = (struct _fpstate *)ucontext->uc_mcontext.fpregs;
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if (fpregs->magic == X86_FXSR_MAGIC)
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return fpregs->sw | fpregs->mxcsr;
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else
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return fpregs->sw;
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}
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inline static void uap_clear_fpu_status(void *uap)
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{
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ucontext_t *ucontext = (ucontext_t *)uap;
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struct _fpstate *fpregs = (struct _fpstate *)ucontext->uc_mcontext.fpregs;
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fpregs->sw = 0;
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if (fpregs->magic == X86_FXSR_MAGIC)
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fpregs->mxcsr &= 0xffffffc0;
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}
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#define UAP_PROGRAM_COUNTER(ucontext) \
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(((ucontext_t *)(ucontext))->uc_mcontext.gregs[14])
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}
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