Early sclp console messages are printed in line mode on z/VM and LPAR,
but under kvm newlines matter. Add a missing newline between "kernel
version" and "Kernel fault".
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
startup pgm check handler is active since the very beginning of kernel
code execution until uncompressed kernel sets up s390_base_pgm_handler.
It is useful not just for the decompressor debugging itself, but also for
early code of uncompressed kernel, in particular Kasan initialization. But
since there is no stack trace or symbolic representation of failing psw
address it is impossible to figure out faulty code location without
knowing Kaslr kernel base. So, let's add it to the startup pgm check
info printed as well.
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Try to print out startup pgm check info including exact linux kernel
version, pgm interruption code and ilc, psw and general registers. Like
the following:
Linux version 5.3.0-rc7-07282-ge7b4d41d61bd-dirty (gor@tuxmaker) #3 SMP PREEMPT Thu Sep 5 16:07:34 CEST 2019
Kernel fault: interruption code 0005 ilc:2
PSW : 0000000180000000 0000000000012e52
R:0 T:0 IO:0 EX:0 Key:0 M:0 W:0 P:0 AS:0 CC:0 PM:0 RI:0 EA:3
GPRS: 0000000000000000 00ffffffffffffff 0000000000000000 0000000000019a58
000000000000bf68 0000000000000000 0000000000000000 0000000000000000
0000000000000000 0000000000000000 000000000001a041 0000000000000000
0000000004c9c000 0000000000010070 0000000000012e42 000000000000beb0
This info makes it apparent that kernel startup failed and might help
to understand what went wrong without actual standalone dump.
Printing code runs on its own stack of 1 page (at unused 0x5000), which
should be sufficient for sclp_early_printk usage (typical stack usage
observed has been around 512 bytes).
The code has pgm check recursion prevention, despite pgm check info
printing failure (follow on pgm check) or success it restores original
faulty psw and gprs and does disabled wait.
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
