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linux/arch/arm/include/asm/ucontext.h
Imre Deak 82c6f5a5b3 ARM: 6051/1: VFP: preserve the HW context when calling signal handlers
From: Imre Deak <imre.deak@nokia.com>

Signal handlers can use floating point, so prevent them to corrupt
the main thread's VFP context. So far there were two signal stack
frame formats defined based on the VFP implementation, but the user
struct used for ptrace covers all posibilities, so use it for the
signal stack too.

Introduce also a new user struct for VFP exception registers. In
this too fields not relevant to the current VFP architecture are
ignored.

Support to save / restore the exception registers was added by
Will Deacon.

Signed-off-by: Imre Deak <imre.deak@nokia.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-04-14 11:11:30 +01:00

103 lines
2.8 KiB
C

#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, preceeded 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 */