uc_access(3)						     Library Functions Manual						      uc_access(3)

NAME

       uc_access:    __uc_get_ar(),    __uc_get_ar_bsp(),    __uc_get_ar_bspstore(),   __uc_get_ar_ccv(),   __uc_get_ar_csd(),	 __uc_get_ar_ec(),
       __uc_get_ar_fpsr(),  __uc_get_ar_lc(),  __uc_get_ar_pfs(),  __uc_get_ar_rsc(),	__uc_get_ar_ssd(),   __uc_get_ar_unat(),   __uc_get_brs(),
       __uc_get_cfm(),	 __uc_get_cr(),   __uc_get_ed(),   __uc_get_frs(),   __uc_get_grs(),   __uc_get_ip(),  __uc_get_prs(),	__uc_get_reason(),
       __uc_get_rsebs(),   __uc_get_rsebs64(),	 __uc_get_um(),    __uc_set_ar(),    __uc_set_ar_ccv(),    __uc_set_ar_csd(),	 __uc_set_ar_ec(),
       __uc_set_ar_fpsr(),   __uc_set_ar_lc(),	 __uc_set_ar_pfs(),   __uc_set_ar_rsc(),  __uc_set_ar_ssd(),  __uc_set_ar_unat(),  __uc_set_brs(),
       __uc_set_cfm(),	__uc_set_ed(),	__uc_set_frs(),  __uc_set_grs(),  __uc_set_ip(),  __uc_set_prs(),  __uc_set_rsebs(),   __uc_set_rsebs64(),
       __uc_set_um() - user context access (ucontext_t)

SYNOPSIS

       Command: [flag]... file... [library]...

DESCRIPTION

       The Ucontext Access interfaces allow an application to access the Integrity register state contained inside the opaque structure within the
       user context structure.

       In all these interfaces, is a pointer to a passed to the application as the third argument to a signal handler, allocated by the  user  and
       filled in with or read from an application file.

       Because	a  syscall  occurs  on a function call boundary, contexts created in a syscall omit scratch registers and other specific values as
       detailed below.

       To use any of these functions, link in the ucontext access library by specifying on the compiler or linker command line.

   Individual Interface Descriptions
       Returns (in the location referenced by the
		 argument) zero if the context was created in a syscall or a non-zero value if the context was created while handling an interrup-
		 tion that occurred while running user code.

       Returns (in the
		 array) the saved values of the Static General Registers in the range through + inclusive, and (in the argument) the corresponding
		 NaT bit values.  Only Static  General	Registers  (GR1-GR31)  may  be	read  with  this  interface.   Stacked	General  Registers
		 (GR32-GR127) must be read from the RSE backing store, or the RSE Backing Store overflow area.	(See below.)

		 The  NaT bits corresponding to the requested General Registers will be in the corresponding bits of NaT.  For example, represents
		 the Nat Bit for GR5.

		 If the context was created in a syscall, scratch registers (GR2, GR3 and GR14-GR31) will read as

       Overwrites the saved values of the Static General Registers in the range
		 through + inclusive, with the contents of the first elements of the array, and overwrites the corresponding NaT  bits	with  bits
		 from  the  argument.	Only  Static  General  Registers (GR1-GR31) may be written with this interface.  Stacked General Registers
		 (GR32-GR127) must be written to the RSE backing store, or the RSE Backing Store overflow area.  (See below.)

		 The NaT bits corresponding to the specified General Registers must be in the corresponding bits of NaT.  For example, the NaT bit
		 for GR5 will be overwritten with

		 If the context was created in a syscall, an attempt to write scratch registers (GR2, GR3 and GR14-GR31) will return

       Returns (in the
		 array) the saved values of the Floating-Point Registers in the range through + inclusive.

		 If the context was created in a syscall, scratch registers (FR6-FR15 and FR32-FR127) will read as

       Overwrites the saved values of the Floating-Point Registers in the range
		 through + inclusive, with the contents of the first elements of the array.

		 If  the  context was created in a syscall, an attempt to write scratch registers (FR6-FR15 and FR32-FR127) will return An attempt
		 to set bits {127:82} of an FP value will return

       Returns (in the location referenced by the
		 argument) the saved values of the Predicate Registers.

		 If the context was created in a syscall, scratch predicates (PR6-PR15) will read as

       Overwrites the saved values of the Predicate Registers with

		 If the context was created in a syscall, an attempt to set scratch predicates (PR6-PR15) will return

		 Attempts to clear PR[0] will be silently ignored.

       Returns (in the
		 array) the saved values of the Branch Registers in the range through + inclusive.

		 If the context was created in a syscall, scratch registers (BR6-BR7) will read as

       Overwrites the saved values of the Branch Registers in the range
		 through + inclusive, with the contents of the first elements of the array.

		 If the context was created in a syscall, an attempt to write scratch registers (BR6-BR7) will return

       Returns (in the
		 argument) the saved value of the Instruction Pointer Register.

		 If the context was created while handling an interruption, will be that of the next instruction to execute.  The instruction slot
		 will  be  indicated  by a value of or in the low-order 2 bits of the For traps and interrupts, it will point to the next instruc-
		 tion.	For faults, it will point to the faulting instruction.	If the context was created  in	a  syscall,  will  be  the  return
		 pointer from the system call.	The low-order 2 bits of the will be

       Overwrites the saved value of the Instruction Pointer Register with

		 If  the context was created while handling an interruption, the instruction slot indicated by the 2 low-order bits of will be the
		 next instruction to execute.  If the context was created in a syscall, an attempt to set the instruction slot to a non-zero value
		 will return

       Returns (in the
		 argument) the saved value of the Current Frame Marker Register.

		 If the context was created in a syscall, will be the frame marker corresponding to the function that called the kernel.

       Overwrites the saved value of the Current Frame Marker Register with

       Returns (in the
		 argument) the saved value of the User Mask Register.

       Overwrites the saved User Mask Register with
		 An attempt to set reserved bits will return

       Returns (in the low-order bit of the
		 argument) the saved value of the Exception Deferral Bit.  This bit is only saved in interruption contexts.  An attempt to read it
		 from a context saved in a syscall will return

       Overwrites the saved Exception Deferral Bit value with the low-order bit of the
		 specified.  This bit is only saved in interruption contexts.  An attempt to write it in a context saved in a syscall will  return
		 An attempt to set it if CR.ISR.ED is not set will return

       Returns (in the
		 argument) the saved value of the register.

       Overwrites the saved value of the
		 register with

       Returns (in the
		 argument)  the  saved	value  of the register.  By convention, this value reflects the effects of the instruction used to enter a
		 syscall or the instruction used in handling an interruption.  To find the value that will be in when the next instruction is exe-
		 cuted the caller must:

		 1)  Call to determine whether the context was created in a syscall or while handling an interruption.

		 2)  Call to fetch the current frame marker.

		 3)  Adjust the value by (for a syscall context) or (for an interruption context).

       Returns (in the
		 argument) the saved value of the register.

       Returns (in the
		 argument) the saved value of the register.  If the context was created in a syscall, the value is undefined.

       Overwrites the saved value of the
		 register with If the context was created in a syscall, this call returns with no other side-effects.

       Returns (in the
		 argument) the saved value of the register.  If the context was created in a syscall, the value is undefined.

       Overwrites the saved value of the
		 register with If the context was created in a syscall, this call returns with no other side-effects.

       Returns (in the
		 argument) the saved value of the register.  If the context was created in a syscall, the value is undefined.

       Overwrites the saved value of the
		 register with If the context was created in a syscall, this call returns with no other side-effects.

       Returns (in the
		 argument) the saved value of the register.

       Overwrites the saved value of the
		 register with

       Returns (in the
		 argument) the saved value of the register.

       Overwrites the saved value of the
		 register with

       Returns (in the
		 argument) the saved value of the register.  In a syscall context, the value returned is undefined.  Use to read the current frame
		 marker and to read the current epilog count.

       Overwrites the saved value of the
		 register with If the context was created in a syscall, returns with no other side-effects.

       Returns (in the
		 argument) the saved value of the register.

       Overwrites the saved value of the
		 register with

       Returns (in the
		 argument) the saved value of the register.

       Overwrites the saved value of the
		 register with the low-order 6 bits of

       Returns (in the
		 argument) the saved value of the Application Register specified by

       Overwrites the saved value of the Application Register specified by
		 with

		 The following Application Registers may be specified:

							      +----+-------------+----+----+
							      |Reg |Register	 |Get |Set |
							      +----+-------------+----+----+
							      |16  |AR_RSC	 |X   |X   |
							      +----+-------------+----+----+
							      |17  |AR_BSP	 |X   |    |
							      +----+-------------+----+----+
							      |18  |AR_BSPSTORE  |X   |X   |
							      +----+-------------+----+----+
							      |25  |AR_AR_CSD(*) |X   |X   |
							      +----+-------------+----+----+
							      |26  |AR_AR_SSD(*) |X   |X   |
							      +----+-------------+----+----+
							      |32  |AR_AR_CCV(*) |X   |X   |
							      +----+-------------+----+----+
							      |36  |AR_UNAT	 |X   |X   |
							      +----+-------------+----+----+
							      |40  |AR_FPSR	 |X   |X   |
							      +----+-------------+----+----+
							      |64  |AR_PFS(+)	 |X   |X   |
							      +----+-------------+----+----+
							      |65  |AR_LC	 |X   |X   |
							      +----+-------------+----+----+
							      |66  |AR_EC	 |X   |X   |
							      +----+-------------+----+----+

			*
		 and are scratch registers.  If the context was created in a syscall, it will read as 0.  An attempt to write it will return

		 + Note the caller should consult the unwind information for the function preceding the delivery of the signal to determine if the
		 register contained valid data.

       Returns (in the
		 argument) the saved value of the Control Register specified by

		 The following Control Registers may be specified:

					    +----+---------+------------------------------------------------+
					    |Reg |Register |Notes					    |
					    +----+---------+------------------------------------------------+
					    |17  |CR_ISR   |						    |
					    +----+---------+------------------------------------------------+
					    |20  |CR_IFA   | Only valid for certain types of interruptions. |
					    +----+---------+------------------------------------------------+
					    |22  |CR_IIPA  |						    |
					    +----+---------+------------------------------------------------+
       If the context was created in a syscall, the control registers will
		 read as 0.

       When a signal handler is invoked, the kernel attempts to write all dirty RSE
		 registers  to	the original RSE backing store.  If it is unable to do this (that is, if the memory is not mapped) the kernel will
		 write remaining dirty registers to an overflow area within the These interfaces are provided to access those values saved in this
		 overflow area.

		 Use to fetch the and values.

					  +------------------------------------------+------------------------+
					  |If the address of the value you want is   |Use		      |
					  +------------------------------------------+------------------------+
					  |addr < AR.BSPSTORE			     |direct read/write       |
					  +------------------------------------------+------------------------+
					  |AR.BSPSTORE <= addr < AR.BSP 	     |__uc_[gs]et_rsebs{64}() |
					  +------------------------------------------+------------------------+
					  |Special case for the last NaT collection: |__uc_[gs]et_rsebs{64}() |
					  |addr == AR.BSP | 0x1f8		     |			      |
					  +------------------------------------------+------------------------+
       The	 bits may be split between the value and the overflow area.

				       +--------------------------------------+-----------------------------------+
				       |Address 			      |Where to find the NaT		  |
				       +--------------------------------------+-----------------------------------+
				       |addr < AR.BSPSTORE & ~0x1ff	      |direct read/write of backing store |
				       +--------------------------------------+-----------------------------------+
				       |AR.BSPSTORE & ~0x1ff <= addr < AR.BSP |__uc_[gs]et_rsebs{64}(addr|0x1f8)  |
				       +--------------------------------------+-----------------------------------+
       For 32-bit callers,
		 and will swizzle the addr argument.

		 are provided for 32-bit callers reading a generated within a 64-bit application.  They differ from in that the addr argument will
		 not be swizzled.  are only included in 32-bit versions of the library.

RETURN VALUE

       Upon successful completion, all the interfaces return 0 to indicate success and return if passed invalid arguments.

ERRORS

       The Ucontext Access interfaces will fail if any of the following conditions are encountered:

	      For any of the interfaces listed above, the
			     argument is NULL, or points to a with an invalid version or size.

	      For the	     or calls the range of registers specified by and included a value outside the range 1 to 31 inclusive.

	      For the	     call, was created by a syscall and the range of registers specified by and included a scratch register.

	      For the	     or calls the range of registers specified by and included a value outside the range 2 to 127 inclusive.

	      For the	     call, was created by a syscall and the range of registers specified by and included a scratch register or an  attempt
			     is made to set bits {127:82} of an FP value.

	      For the	     call, was created by a syscall and included a set scratch bit or bits.

	      For the	     or calls the range of registers specified by and included a value outside the range 0 to 7 inclusive.

	      For the	     call, was created by a syscall and the range of registers specified by and included a scratch register.

	      For the	     call,  was  created  by a syscall and the low-order two bits of are not zero, or was not created by a syscall and the
			     low-order two bits of are

	      For the	     call, bits outside the range 37:0 are set.

	      For the	     call, bits outside the range 5:1 are set.

	      For the	     or calls, a reserved field is non-zero.

	      For the	     or calls, an invalid register is specified.

	      For the	     call, specifies a valid register and includes reserved bits that are set.

	      For the	     or calls, was created in a system call.

	      For the	     call, includes bits set other than the low-order bit or the low-order bit is set  and  the  saved	CR.ISR.ED  bit	is
			     clear.

	      For the	     or  calls,  the  range of memory locations specified by and includes values outside the range (inclusive) and (exclu-
			     sive) or if specifying the last NaT collection location, != 1

WARNINGS

       Only minimal argument checking is performed.  The caller must take care not to write invalid or out-of-range values to any register or reg-
       ister  field.  The effects of returning from a signal handler or calling after overwriting any register with invalid or out-of-range values
       are undefined.

       is deprecated and should be used only by legacy applications.  and are the recommended replacements.

       is deprecated and should be used only by legacy applications.  and are the recommended replacements.  is deprecated and should be used only
       by legacy applications.

AUTHOR

       The UContext Access library was developed by HP.

FILES

       Prototypes for the interfaces

SEE ALSO

       getcontext(2), sigaction(2), core(4), signal(5), <ucontext.h>.

Integrity Systems Only														      uc_access(3)