ucontext.h

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#ifndef _ASMARM_UCONTEXT_H
#define _ASMARM_UCONTEXT_H

#include <asm/fpstate.h>

/*
 * struct sigcontext only has room for the basic registers, but struct
 * ucontext now has room for all registers which need to be saved and
 * restored.  Coprocessor registers are stored in uc_regspace.  Each
 * coprocessor's saved state should start with a documented 32-bit magic
 * number, followed by a 32-bit word giving the coproccesor's saved size.
 * uc_regspace may be expanded if necessary, although this takes some
 * coordination with glibc.
 */

struct ucontext {
    unsigned long     uc_flags;
    struct ucontext  *uc_link;
    stack_t       uc_stack;
    struct sigcontext uc_mcontext;
    sigset_t      uc_sigmask;
    /* Allow for uc_sigmask growth.  Glibc uses a 1024-bit sigset_t.  */
    int       __unused[32 - (sizeof (sigset_t) / sizeof (int))];
    /* Last for extensibility.  Eight byte aligned because some
       coprocessors require eight byte alignment.  */
    unsigned long     uc_regspace[128] __attribute__((__aligned__(8)));
};

#ifdef __KERNEL__

/*
 * Coprocessor save state.  The magic values and specific
 * coprocessor's layouts are part of the userspace ABI.  Each one of
 * these should be a multiple of eight bytes and aligned to eight
 * bytes, to prevent unpredictable padding in the signal frame.
 */

#ifdef CONFIG_CRUNCH
#define CRUNCH_MAGIC        0x5065cf03
#define CRUNCH_STORAGE_SIZE (CRUNCH_SIZE + 8)

struct crunch_sigframe {
    unsigned long   magic;
    unsigned long   size;
    struct crunch_state storage;
} __attribute__((__aligned__(8)));
#endif

#ifdef CONFIG_IWMMXT
/* iwmmxt_area is 0x98 bytes long, preceded by 8 bytes of signature */
#define IWMMXT_MAGIC        0x12ef842a
#define IWMMXT_STORAGE_SIZE (IWMMXT_SIZE + 8)

struct iwmmxt_sigframe {
    unsigned long   magic;
    unsigned long   size;
    struct iwmmxt_struct storage;
} __attribute__((__aligned__(8)));
#endif /* CONFIG_IWMMXT */

#ifdef CONFIG_VFP
#define VFP_MAGIC       0x56465001

struct vfp_sigframe
{
    unsigned long       magic;
    unsigned long       size;
    struct user_vfp     ufp;
    struct user_vfp_exc ufp_exc;
} __attribute__((__aligned__(8)));

/*
 *  8 byte for magic and size, 264 byte for ufp, 12 bytes for ufp_exc,
 *  4 bytes padding.
 */
#define VFP_STORAGE_SIZE    sizeof(struct vfp_sigframe)

#endif /* CONFIG_VFP */

/*
 * Auxiliary signal frame.  This saves stuff like FP state.
 * The layout of this structure is not part of the user ABI,
 * because the config options aren't.  uc_regspace is really
 * one of these.
 */
struct aux_sigframe {
#ifdef CONFIG_CRUNCH
    struct crunch_sigframe  crunch;
#endif
#ifdef CONFIG_IWMMXT
    struct iwmmxt_sigframe  iwmmxt;
#endif
#ifdef CONFIG_VFP
    struct vfp_sigframe vfp;
#endif
    /* Something that isn't a valid magic number for any coprocessor.  */
    unsigned long       end_magic;
} __attribute__((__aligned__(8)));

#endif

#endif /* !_ASMARM_UCONTEXT_H */