In the copy(9) function, make sure to remember curproc accross the bcopy()

call, instead of &curproc. The copy routine may sleep and we may resume on
a different processor. This has been plaguing the alpha MULTIPROCESSOR kernels
since the very beginning; it's amazing this did not cause more havoc.

Joint debugging and hair pulling with dlg@ and deraadt@; ok dlg@

diff --git a/sys/arch/alpha/alpha/locore.s b/sys/arch/alpha/alpha/locore.s
index f19900a..8505a39 100644 (file)
--- a/sys/arch/alpha/alpha/locore.s
+++ b/sys/arch/alpha/alpha/locore.s
@@ -1,4 +1,4 @@
-/* $OpenBSD: locore.s,v 1.41 2015/06/11 17:26:17 deraadt Exp $ */
+/* $OpenBSD: locore.s,v 1.42 2015/06/23 19:49:41 miod Exp $ */
 /* $NetBSD: locore.s,v 1.94 2001/04/26 03:10:44 ross Exp $ */
 
 /*-
@@ -892,20 +892,18 @@ NESTED(copyinstr, 4, 16, ra, IM_RA|IM_S0, 0)
        stq     s0, (16-16)(sp)                 /* save s0                   */
        /* Note: GET_CURPROC clobbers v0, t0, t8...t11. */
        GET_CURPROC
-       mov     v0, s0
+       ldq     s0, 0(v0)
        ldiq    t0, VM_MAX_ADDRESS              /* make sure that src addr   */
        cmpult  a0, t0, t1                      /* is in user space.         */
        beq     t1, copyerr                     /* if it's not, error out.   */
        lda     v0, copyerr                     /* set up fault handler.     */
        .set noat
-       ldq     at_reg, 0(s0)
-       ldq     at_reg, P_ADDR(at_reg)
+       ldq     at_reg, P_ADDR(s0)
        stq     v0, U_PCB_ONFAULT(at_reg)
        .set at
        CALL(copystr)                           /* do the copy.              */
        .set noat
-       ldq     at_reg, 0(s0)                   /* kill the fault handler.   */
-       ldq     at_reg, P_ADDR(at_reg)
+       ldq     at_reg, P_ADDR(s0)
        stq     zero, U_PCB_ONFAULT(at_reg)
        .set at
        ldq     ra, (16-8)(sp)                  /* restore ra.               */
@@ -921,20 +919,18 @@ NESTED(copyoutstr, 4, 16, ra, IM_RA|IM_S0, 0)
        stq     s0, (16-16)(sp)                 /* save s0                   */
        /* Note: GET_CURPROC clobbers v0, t0, t8...t11. */
        GET_CURPROC
-       mov     v0, s0
+       ldq     s0, 0(v0)
        ldiq    t0, VM_MAX_ADDRESS              /* make sure that dest addr  */
        cmpult  a1, t0, t1                      /* is in user space.         */
        beq     t1, copyerr                     /* if it's not, error out.   */
        lda     v0, copyerr                     /* set up fault handler.     */
        .set noat
-       ldq     at_reg, 0(s0)
-       ldq     at_reg, P_ADDR(at_reg)
+       ldq     at_reg, P_ADDR(s0)
        stq     v0, U_PCB_ONFAULT(at_reg)
        .set at
        CALL(copystr)                           /* do the copy.              */
        .set noat
-       ldq     at_reg, 0(s0)                   /* kill the fault handler.   */
-       ldq     at_reg, P_ADDR(at_reg)
+       ldq     at_reg, P_ADDR(s0)              /* kill the fault handler.   */
        stq     zero, U_PCB_ONFAULT(at_reg)
        .set at
        ldq     ra, (16-8)(sp)                  /* restore ra.               */
@@ -961,18 +957,16 @@ NESTED(kcopy, 3, 32, ra, IM_RA|IM_S0|IM_S1, 0)
        stq     s1, (32-24)(sp)                 /* save s1                   */
        /* Note: GET_CURPROC clobbers v0, t0, t8...t11. */
        GET_CURPROC
-       mov     v0, s1
+       ldq     s1, 0(v0)
        lda     v0, kcopyerr                    /* set up fault handler.     */
        .set noat
-       ldq     at_reg, 0(s1)
-       ldq     at_reg, P_ADDR(at_reg)
+       ldq     at_reg, P_ADDR(s1)
        ldq     s0, U_PCB_ONFAULT(at_reg)       /* save old handler.         */
        stq     v0, U_PCB_ONFAULT(at_reg)
        .set at
        CALL(bcopy)                             /* do the copy.              */
        .set noat
-       ldq     at_reg, 0(s1)                   /* restore the old handler.  */
-       ldq     at_reg, P_ADDR(at_reg)
+       ldq     at_reg, P_ADDR(s1)              /* restore the old handler.  */
        stq     s0, U_PCB_ONFAULT(at_reg)
        .set at
        ldq     ra, (32-8)(sp)                  /* restore ra.               */
@@ -986,8 +980,7 @@ NESTED(kcopy, 3, 32, ra, IM_RA|IM_S0|IM_S1, 0)
 LEAF(kcopyerr, 0)
        LDGP(pv)
        .set noat
-       ldq     at_reg, 0(s1)                   /* restore the old handler.  */
-       ldq     at_reg, P_ADDR(at_reg)
+       ldq     at_reg, P_ADDR(s1)              /* restore the old handler.  */
        stq     s0, U_PCB_ONFAULT(at_reg)
        .set at
        ldq     ra, (32-8)(sp)                  /* restore ra.               */
@@ -1005,20 +998,18 @@ NESTED(copyin, 3, 16, ra, IM_RA|IM_S0, 0)
        stq     s0, (16-16)(sp)                 /* save s0                   */
        /* Note: GET_CURPROC clobbers v0, t0, t8...t11. */
        GET_CURPROC
-       mov     v0, s0
+       ldq     s0, 0(v0)
        ldiq    t0, VM_MAX_ADDRESS              /* make sure that src addr   */
        cmpult  a0, t0, t1                      /* is in user space.         */
        beq     t1, copyerr                     /* if it's not, error out.   */
        lda     v0, copyerr                     /* set up fault handler.     */
        .set noat
-       ldq     at_reg, 0(s0)
-       ldq     at_reg, P_ADDR(at_reg)
+       ldq     at_reg, P_ADDR(s0)
        stq     v0, U_PCB_ONFAULT(at_reg)
        .set at
        CALL(bcopy)                             /* do the copy.              */
        .set noat
-       ldq     at_reg, 0(s0)                   /* kill the fault handler.   */
-       ldq     at_reg, P_ADDR(at_reg)
+       ldq     at_reg, P_ADDR(s0)              /* kill the fault handler.   */
        stq     zero, U_PCB_ONFAULT(at_reg)
        .set at
        ldq     ra, (16-8)(sp)                  /* restore ra.               */
@@ -1035,20 +1026,18 @@ NESTED(copyout, 3, 16, ra, IM_RA|IM_S0, 0)
        stq     s0, (16-16)(sp)                 /* save s0                   */
        /* Note: GET_CURPROC clobbers v0, t0, t8...t11. */
        GET_CURPROC
-       mov     v0, s0
+       ldq     s0, 0(v0)
        ldiq    t0, VM_MAX_ADDRESS              /* make sure that dest addr  */
        cmpult  a1, t0, t1                      /* is in user space.         */
        beq     t1, copyerr                     /* if it's not, error out.   */
        lda     v0, copyerr                     /* set up fault handler.     */
        .set noat
-       ldq     at_reg, 0(s0)
-       ldq     at_reg, P_ADDR(at_reg)
+       ldq     at_reg, P_ADDR(s0)
        stq     v0, U_PCB_ONFAULT(at_reg)
        .set at
        CALL(bcopy)                             /* do the copy.              */
        .set noat
-       ldq     at_reg, 0(s0)                   /* kill the fault handler.   */
-       ldq     at_reg, P_ADDR(at_reg)
+       ldq     at_reg, P_ADDR(s0)              /* kill the fault handler.   */
        stq     zero, U_PCB_ONFAULT(at_reg)
        .set at
        ldq     ra, (16-8)(sp)                  /* restore ra.               */
@@ -1061,8 +1050,7 @@ NESTED(copyout, 3, 16, ra, IM_RA|IM_S0, 0)
 LEAF(copyerr, 0)
        LDGP(pv)
        .set noat
-       ldq     at_reg, 0(s0)                   /* kill the fault handler.   */
-       ldq     at_reg, P_ADDR(at_reg)
+       ldq     at_reg, P_ADDR(s0)              /* kill the fault handler.   */
        stq     zero, U_PCB_ONFAULT(at_reg)
        .set at
        ldq     ra, (16-8)(sp)                  /* restore ra.               */