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authorVasily Gorbik <gor@linux.ibm.com>2019-08-08 20:09:08 +0200
committerHeiko Carstens <heiko.carstens@de.ibm.com>2019-09-13 12:17:37 +0200
commit724dc336b79ff965bd5773257642685cf33ed9af (patch)
tree07e170c62e17f6158f1fa8be0e489b6802c8ecfa /arch/s390/boot/head.S
parent9e323d45ba94262620a073a3f9945ca927c07c71 (diff)
downloadlinux-724dc336b79ff965bd5773257642685cf33ed9af.tar.bz2
s390/startup: add pgm check info printing
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>
Diffstat (limited to 'arch/s390/boot/head.S')
-rw-r--r--arch/s390/boot/head.S10
1 files changed, 9 insertions, 1 deletions
diff --git a/arch/s390/boot/head.S b/arch/s390/boot/head.S
index 5b79ae7b44f3..4b86a8d3c121 100644
--- a/arch/s390/boot/head.S
+++ b/arch/s390/boot/head.S
@@ -365,12 +365,20 @@ ENTRY(startup_pgm_check_handler)
stctg %c0,%c15,__LC_CREGS_SAVE_AREA-4095(%r1)
mvc __LC_GPREGS_SAVE_AREA-4095(128,%r1),__LC_SAVE_AREA_SYNC
mvc __LC_PSW_SAVE_AREA-4095(16,%r1),__LC_PGM_OLD_PSW
- lg %r1,__LC_SAVE_AREA_SYNC+8
mvc __LC_RETURN_PSW(16),__LC_PGM_OLD_PSW
ni __LC_RETURN_PSW,0xfc # remove IO and EX bits
ni __LC_RETURN_PSW+1,0xfb # remove MCHK bit
oi __LC_RETURN_PSW+1,0x2 # set wait state bit
+ larl %r2,.Lold_psw_disabled_wait
+ stg %r2,__LC_PGM_NEW_PSW+8
+ l %r15,.Ldump_info_stack-.Lold_psw_disabled_wait(%r2)
+ brasl %r14,print_pgm_check_info
+.Lold_psw_disabled_wait:
+ la %r1,4095
+ lmg %r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1)
lpswe __LC_RETURN_PSW # disabled wait
+.Ldump_info_stack:
+ .long 0x5000 + PAGE_SIZE - STACK_FRAME_OVERHEAD
ENDPROC(startup_pgm_check_handler)
#