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UNW_SET_REG(3)		     Programming Library		UNW_SET_REG(3)

NAME
       unw_set_reg -- set register contents

SYNOPSIS
       #include	<libunwind.h>

       int unw_set_reg(unw_cursor_t *cp, unw_regnum_t reg, unw_word_t val);

DESCRIPTION
       The  unw_set_reg()  routine sets	the value of register reg in the stack
       frame identified	by cursor cp to	the value passed in val.

       The register numbering is target-dependent and  described  in  separate
       manual  pages (e.g., libunwind-ia64(3) for the IA-64 target).  Further-
       more, the exact set of accessible registers may depend on the  type  of
       frame  that  cp	is referring to. For ordinary stack frames, it is nor-
       mally possible to access	only the preserved  (``callee-saved'')	regis-
       ters  and frame-related registers (such as the stack-pointer). However,
       for signal frames (see unw_is_signal_frame(3)), it is usually  possible
       to access all registers.

       Note  that unw_set_reg()	can only write the contents of registers whose
       values fit in a single word. See	unw_set_fpreg(3) for a	way  to	 write
       registers which do not fit this constraint.

RETURN VALUE
       On successful completion, unw_set_reg() returns 0.  Otherwise the nega-
       tive value of one of the	error-codes below is returned.

THREAD AND SIGNAL SAFETY
       unw_set_reg() is	thread-safe as well as safe to use from	a signal  han-
       dler.

ERRORS
       UNW_EUNSPEC
	       An unspecified error occurred.

       UNW_EBADREG
	       An  attempt was made to write a register	that is	either invalid
	      or not accessible	in the current frame.

       UNW_EREADONLY
	       An attempt was made to write to a read-only register.

       In addition, unw_set_reg() may return any error	returned  by  the  ac-
       cess_mem(),  access_reg(),  and access_fpreg() call-backs (see unw_cre-
       ate_addr_space(3)).

SEE ALSO
       libunwind(3),	libunwind-ia64(3),     unw_get_reg(3),	   unw_is_sig-
       nal_frame(3), unw_set_fpreg(3)

AUTHOR
       David Mosberger-Tang
       Email: dmosberger@gmail.com
       WWW: http://www.nongnu.org/libunwind/.

Programming Library		16 August 2007			UNW_SET_REG(3)

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | THREAD AND SIGNAL SAFETY | ERRORS | SEE ALSO | AUTHOR

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