Module Name: src
Committed By: palle
Date: Sun Jan 31 19:08:05 UTC 2021
Modified Files:
src/sys/arch/sparc64/doc: TODO
Log Message:
sun4v: update TODO with analysis of sun4v crashes
To generate a diff of this commit:
cvs rdiff -u -r1.31 -r1.32 src/sys/arch/sparc64/doc/TODO
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/sparc64/doc/TODO
diff -u src/sys/arch/sparc64/doc/TODO:1.31 src/sys/arch/sparc64/doc/TODO:1.32
--- src/sys/arch/sparc64/doc/TODO:1.31 Mon Jan 4 15:13:50 2021
+++ src/sys/arch/sparc64/doc/TODO Sun Jan 31 19:08:05 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: TODO,v 1.31 2021/01/04 15:13:50 skrll Exp $ */
+/* $NetBSD: TODO,v 1.32 2021/01/31 19:08:05 palle Exp $ */
Things to be done:
@@ -11,9 +11,22 @@ sun4u:
- GENERIC.UP kernel hangs on v445 (missing interrupt?)
sun4v:
- - current status: The kernel boots and starts the init process.
- The following processes seem to crash on and on so more debugging to be done...
-
+ - current status:
+ The kernel boots and starts userland.
+ During the execution of the sysinst process, a sub-process crashes.
+ The crash happens when a call to sysctl from /bin/sh causes a mmu trap.
+ Part of the TRAP_SETUP() call in sun4v_datatrap issues a 'save' instruction.
+ Since %cansave is 0 (%canrestore is 6 and %otherwin is 0) a SPILL trap is generated.
+ The current code ends up in the pcbspill codepath (which is based on code from openbsd).
+ This code assumes that it is the register window in the OTHERWIN window that must be spilled
+ to the pcb.
+ Since %otherwin in this scenario actually is zero, we end up putting incorrect register
+ window values to the pcb.
+ So - this code should not save data to the pcb when %otherwin is 0 - it should spill the
+ values to the stack of the user process. Special care should be taken here, since we
+ may end up with a mmu fault again if the stack address is not present in the mmu, so
+ perhaps spilling to the physical address of the stack will work.
+ Time will show if this is correct...
- 64-bit kernel support
- 32-bit kernel support
- libkvm
