Home | History | Annotate | Line # | Download | only in sys 
      1 /*	$NetBSD: __sigtramp2.S,v 1.8 2021/11/20 19:26:20 thorpej Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1994, 1995, 1996 Carnegie-Mellon University.
      5  * All rights reserved.
      6  *
      7  * Author: Chris G. Demetriou
      8  *
      9  * Permission to use, copy, modify and distribute this software and
     10  * its documentation is hereby granted, provided that both the copyright
     11  * notice and this permission notice appear in all copies of the
     12  * software, derivative works or modified versions, and any portions
     13  * thereof, and that both notices appear in supporting documentation.
     14  *
     15  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
     16  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
     17  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
     18  *
     19  * Carnegie Mellon requests users of this software to return to
     20  *
     21  *  Software Distribution Coordinator  or  Software.Distribution (at) CS.CMU.EDU
     22  *  School of Computer Science
     23  *  Carnegie Mellon University
     24  *  Pittsburgh PA 15213-3890
     25  *
     26  * any improvements or extensions that they make and grant Carnegie the
     27  * rights to redistribute these changes.
     28  */
     29 
     30 #include "SYS.h"
     31 #include "assym.h"
     32 
     33 /*
     34  * The Alpha signal trampoline is invoked only to return from
     35  * the signal; the kernel calls the signal handler directly.
     36  *
     37  * On entry, the stack looks like:
     38  *
     39  *		ucontext structure	[128] == sp + sizeof(siginfo_t)]
     40  *	sp->	siginfo structure	[0]
     41  *
     42  * The DWARF register numbers for the general purpose registers are the
     43  * same as the architected register numbers.  For Alpha, there is a DWARF
     44  * pseudo-register for signal handler return addresses.
     45  */
     46 
     47 #if defined(__LIBGCC_DWARF_ALT_FRAME_RETURN_COLUMN__)
     48 #define	DWARF_SIGRETURN_REG		__LIBGCC_DWARF_ALT_FRAME_RETURN_COLUMN__
     49 #else
     50 #define	DWARF_SIGRETURN_REG		64
     51 #endif
     52 
     53 #define	CFI_OFFSET_DWARF_REG(d, r)	.cfi_offset d, r*8
     54 #define	CFI_OFFSET(r)			CFI_OFFSET_DWARF_REG(r, r)
     55 
     56 	.cfi_startproc simple
     57 	.cfi_signal_frame
     58 	.cfi_def_cfa _REG_SP, SIZEOF_SIGINFO + UC_GREGS
     59 	CFI_OFFSET(_REG_V0)
     60 	CFI_OFFSET(_REG_T0)
     61 	CFI_OFFSET(_REG_T1)
     62 	CFI_OFFSET(_REG_T2)
     63 	CFI_OFFSET(_REG_T3)
     64 	CFI_OFFSET(_REG_T4)
     65 	CFI_OFFSET(_REG_T5)
     66 	CFI_OFFSET(_REG_T6)
     67 	CFI_OFFSET(_REG_T7)
     68 	CFI_OFFSET(_REG_S0)
     69 	CFI_OFFSET(_REG_S1)
     70 	CFI_OFFSET(_REG_S2)
     71 	CFI_OFFSET(_REG_S3)
     72 	CFI_OFFSET(_REG_S4)
     73 	CFI_OFFSET(_REG_S5)
     74 	CFI_OFFSET(_REG_S6)
     75 	CFI_OFFSET(_REG_A0)
     76 	CFI_OFFSET(_REG_A1)
     77 	CFI_OFFSET(_REG_A2)
     78 	CFI_OFFSET(_REG_A3)
     79 	CFI_OFFSET(_REG_A4)
     80 	CFI_OFFSET(_REG_A5)
     81 	CFI_OFFSET(_REG_T8)
     82 	CFI_OFFSET(_REG_T9)
     83 	CFI_OFFSET(_REG_T10)
     84 	CFI_OFFSET(_REG_T11)
     85 	CFI_OFFSET(_REG_RA)
     86 	CFI_OFFSET(_REG_T12)	/* a.k.a. _REG_PV */
     87 	CFI_OFFSET(_REG_AT)
     88 	CFI_OFFSET(_REG_GP)
     89 	CFI_OFFSET(_REG_SP)
     90 	.cfi_return_column DWARF_SIGRETURN_REG
     91 	CFI_OFFSET_DWARF_REG(DWARF_SIGRETURN_REG, _REG_PC)
     92 
     93 /*
     94  * The unwind entry includes one instruction slot prior to the trampoline
     95  * because the unwinder will look up to (return PC - 1 insn) while unwinding.
     96  * Normally this would be the jump / branch, but since there isn't one in
     97  * this case, we place an explicit nop there instead.
     98  */
     99 	nop
    100 
    101 NESTED_NOPROFILE(__sigtramp_siginfo_2,0,0,ra,0,0)
    102 	ldgp	gp,0(ra)
    103 	lda	a0,(SIZEOF_SIGINFO)(sp)	/* get pointer to ucontext */
    104 	CALLSYS_NOERROR(setcontext)	/* and call setcontext() with it */
    105 	ldiq	a0,-1			/* if that failed, set an exit code */
    106 	CALLSYS_NOERROR(exit)		/* and call exit() */
    107 	.cfi_endproc
    108 END(__sigtramp_siginfo_2)
    109