[src/trunk]: src/sys/arch/alpha/alpha Fix entering the kernel debugger when M...

[thorpej <thorpej%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/1cd65f4d791a
branches:  trunk
changeset: 944093:1cd65f4d791a
user:      thorpej <thorpej%NetBSD.org@localhost>
date:      Fri Sep 18 00:04:58 2020 +0000

description:
Fix entering the kernel debugger when MULTIPROCESSOR is enabled; the
arguments to alpha_debug() were getting clobbered by the call to
cpu_pause_resume_all(), but they need to be passed along to ddb_trap().

diffstat:

 sys/arch/alpha/alpha/debug.s |  52 ++++++++++++++++++++++++++++++++-----------
 1 files changed, 38 insertions(+), 14 deletions(-)

diffs (103 lines):

diff -r 4cb26bb9b0fc -r 1cd65f4d791a sys/arch/alpha/alpha/debug.s
--- a/sys/arch/alpha/alpha/debug.s      Fri Sep 18 00:02:43 2020 +0000
+++ b/sys/arch/alpha/alpha/debug.s      Fri Sep 18 00:04:58 2020 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: debug.s,v 1.12 2009/08/20 21:34:03 skrll Exp $ */
+/* $NetBSD: debug.s,v 1.13 2020/09/18 00:04:58 thorpej Exp $ */
 
 /*-
  * Copyright (c) 1999, 2001 The NetBSD Foundation, Inc.
@@ -30,9 +30,10 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
-__KERNEL_RCSID(6, "$NetBSD: debug.s,v 1.12 2009/08/20 21:34:03 skrll Exp $")
+__KERNEL_RCSID(6, "$NetBSD: debug.s,v 1.13 2020/09/18 00:04:58 thorpej Exp $")
 
 #include "opt_multiprocessor.h"
+#include "opt_ddb.h"
 #include "opt_kgdb.h"
 
 /*
@@ -64,17 +65,30 @@
  *             a3      kernel trap entry point
  *             a4      frame pointer
  */
-NESTED_NOPROFILE(alpha_debug, 5, 32, ra, IM_RA|IM_S0, 0)
+NESTED_NOPROFILE(alpha_debug, 5, 64, ra,
+    IM_RA|IM_S0|IM_S1|IM_S2|IM_S3|IM_S4|IM_S5, 0)
        br      pv, 1f
 1:     LDGP(pv)
        lda     t0, FRAME_SIZE*8(a4)    /* what would sp have been? */
        stq     t0, FRAME_SP*8(a4)      /* belatedly save sp for ddb view */
-       lda     sp, -32(sp)             /* set up stack frame */
-       stq     ra, (32-8)(sp)          /* save ra */
-       stq     s0, (32-16)(sp)         /* save s0 */
+       lda     sp, -64(sp)             /* set up stack frame */
+       stq     s0, (0*8)(sp)           /* save s0 ... */
+       stq     s1, (1*8)(sp)
+       stq     s2, (2*8)(sp)
+       stq     s3, (3*8)(sp)
+       stq     s4, (4*8)(sp)
+       stq     s5, (5*8)(sp)           /* ... through s5 */
+       stq     ra, (6*8)(sp)           /* save ra */
 
        /* Remember our current stack pointer. */
-       mov     sp, s0
+       mov     sp, s5
+
+       /* Save off our arguments. */
+       mov     a0, s0
+       mov     a1, s1
+       mov     a2, s2
+       mov     a3, s3
+       mov     a4, s4
 
 #if defined(MULTIPROCESSOR)
        /* Pause all other CPUs. */
@@ -95,19 +109,24 @@
 
 2:     lda     sp, debug_stack_top     /* sp <- debug_stack_top */
 
-3:     /* Dispatch to the debugger - arguments are already in place. */
+3:     /* Dispatch to the debugger. */
 #if defined(KGDB)
-       mov     a3, a0                  /* a0 == entry (trap type) */
-       mov     a4, a1                  /* a1 == frame pointer */
+       mov     s3, a0                  /* a0 == entry (trap type) */
+       mov     s4, a1                  /* a1 == frame pointer */
        CALL(kgdb_trap)
        br      9f
 #endif
 #if defined(DDB)
+       mov     s0, a1                  /* same arguments as the call */
+       mov     s1, a1                  /* to alpha_debug() */
+       mov     s2, a2                  /* (these may have been clobbered */
+       mov     s3, a3                  /* when pausing other CPUs.) */
+       mov     s4, a4
        CALL(ddb_trap)
        br      9f
 #endif
 9:     /* Debugger return value in v0; switch back to our previous stack. */
-       mov     s0, sp
+       mov     s5, sp
 
 #if defined(MULTIPROCESSOR)
        mov     v0, s0
@@ -119,8 +138,13 @@
        mov     s0, v0
 #endif
 
-       ldq     ra, (32-8)(sp)          /* restore ra */
-       ldq     s0, (32-16)(sp)         /* restore s0 */
-       lda     sp, 32(sp)              /* pop stack frame */
+       ldq     s0, (0*8)(sp)           /* restore s0 ... */
+       ldq     s1, (1*8)(sp)
+       ldq     s2, (2*8)(sp)
+       ldq     s3, (3*8)(sp)
+       ldq     s4, (4*8)(sp)
+       ldq     s5, (5*8)(sp)           /* ... through s5 */
+       ldq     ra, (6*8)(sp)           /* restore ra */
+       lda     sp, 64(sp)              /* pop stack frame */
        RET
        END(alpha_debug)