Commit 49542002 authored by David Mosberger's avatar David Mosberger

ia64: Fix return path of signal delivery for sigaltstack() case.

parent 35da881b
...@@ -2,7 +2,7 @@ ...@@ -2,7 +2,7 @@
* This file contains the code that gets mapped at the upper end of each task's text * This file contains the code that gets mapped at the upper end of each task's text
* region. For now, it contains the signal trampoline code only. * region. For now, it contains the signal trampoline code only.
* *
* Copyright (C) 1999-2001 Hewlett-Packard Co * Copyright (C) 1999-2002 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com> * David Mosberger-Tang <davidm@hpl.hp.com>
*/ */
...@@ -135,7 +135,7 @@ back_from_setup_rbs: ...@@ -135,7 +135,7 @@ back_from_setup_rbs:
;; ;;
ld8 r8=[base0] // restore (perhaps modified) CFM0, EC0, and CPL0 ld8 r8=[base0] // restore (perhaps modified) CFM0, EC0, and CPL0
cmp.ne p8,p0=r14,r15 // do we need to restore the rbs? cmp.ne p8,p0=r14,r15 // do we need to restore the rbs?
(p8) br.cond.spnt restore_rbs // yup -> (clobbers r14 and r16) (p8) br.cond.spnt restore_rbs // yup -> (clobbers r14-r18, f6 & f7)
;; ;;
back_from_restore_rbs: back_from_restore_rbs:
adds base0=(FR6_OFF+SIGCONTEXT_OFF),sp adds base0=(FR6_OFF+SIGCONTEXT_OFF),sp
...@@ -189,20 +189,69 @@ setup_rbs: ...@@ -189,20 +189,69 @@ setup_rbs:
.spillsp ar.rnat, RNAT_OFF+SIGCONTEXT_OFF .spillsp ar.rnat, RNAT_OFF+SIGCONTEXT_OFF
.body .body
restore_rbs: restore_rbs:
// On input:
// r14 = bsp1 (bsp at the time of return from signal handler)
// r15 = bsp0 (bsp at the time the signal occurred)
//
// Here, we need to calculate bspstore0, the value that ar.bspstore needs
// to be set to, based on bsp0 and the size of the dirty partition on
// the alternate stack (sc_loadrs >> 16). This can be done with the
// following algorithm:
//
// bspstore0 = rse_skip_regs(bsp0, -rse_num_regs(bsp1 - (loadrs >> 19), bsp1));
//
// This is what the code below does.
//
alloc r2=ar.pfs,0,0,0,0 // alloc null frame alloc r2=ar.pfs,0,0,0,0 // alloc null frame
adds r16=(LOADRS_OFF+SIGCONTEXT_OFF),sp adds r16=(LOADRS_OFF+SIGCONTEXT_OFF),sp
adds r18=(RNAT_OFF+SIGCONTEXT_OFF),sp
;; ;;
ld8 r14=[r16] ld8 r17=[r16]
adds r16=(RNAT_OFF+SIGCONTEXT_OFF),sp ld8 r16=[r18] // get new rnat
extr.u r18=r15,3,6 // r18 <- rse_slot_num(bsp0)
;; ;;
mov ar.rsc=r14 // put RSE into enforced lazy mode mov ar.rsc=r17 // put RSE into enforced lazy mode
ld8 r14=[r16] // get new rnat shr.u r17=r17,16
;; ;;
loadrs // restore dirty partition sub r14=r14,r17 // r14 (bspstore1) <- bsp1 - (sc_loadrs >> 16)
shr.u r17=r17,3 // r17 <- (sc_loadrs >> 19)
;;
loadrs // restore dirty partition
extr.u r14=r14,3,6 // r14 <- rse_slot_num(bspstore1)
;;
add r14=r14,r17 // r14 <- rse_slot_num(bspstore1) + (sc_loadrs >> 19)
;;
shr.u r14=r14,6 // r14 <- (rse_slot_num(bspstore1) + (sc_loadrs >> 19))/0x40
;;
sub r14=r14,r17 // r14 <- -rse_num_regs(bspstore1, bsp1)
movl r17=0x8208208208208209
;;
add r18=r18,r14 // r18 (delta) <- rse_slot_num(bsp0) - rse_num_regs(bspstore1,bsp1)
setf.sig f7=r17
cmp.lt p7,p0=r14,r0 // p7 <- (r14 < 0)?
;;
(p7) adds r18=-62,r18 // delta -= 62
;;
setf.sig f6=r18
;;
xmpy.h f6=f6,f7
;;
getf.sig r17=f6
;;
add r17=r17,r18
shr r18=r18,63
;;
shr r17=r17,5
;;
sub r17=r17,r18 // r17 = delta/63
;;
add r17=r14,r17 // r17 <- delta/63 - rse_num_regs(bspstore1, bsp1)
;;
shladd r15=r17,3,r15 // r15 <- bsp0 + 8*(delta/63 - rse_num_regs(bspstore1, bsp1))
;; ;;
mov ar.bspstore=r15 // switch back to old register backing store area mov ar.bspstore=r15 // switch back to old register backing store area
;; ;;
mov ar.rnat=r14 // restore RNaT mov ar.rnat=r16 // restore RNaT
mov ar.rsc=0xf // (will be restored later on from sc_ar_rsc) mov ar.rsc=0xf // (will be restored later on from sc_ar_rsc)
// invala not necessary as that will happen when returning to user-mode // invala not necessary as that will happen when returning to user-mode
br.cond.sptk back_from_restore_rbs br.cond.sptk back_from_restore_rbs
......
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