From 8977ab65b894d889c3919581bf545ed106a9a1a5 Mon Sep 17 00:00:00 2001 From: Vasily Gorbik Date: Tue, 10 Nov 2020 17:05:35 +0100 Subject: s390/decompressor: add stacktrace support Decompressor works on a single statically allocated stack. Stacktrace implementation with -mbackchain just takes few lines of code. Linux version 5.10.0-rc3-22793-g0f84a355b776-dirty (gor@tuxmaker) #27 SMP PREEMPT Mon Nov 9 17:30:18 CET 2020 Kernel fault: interruption code 0005 ilc:2 PSW : 0000000180000000 0000000000012f92 (parse_boot_command_line+0x27a/0x46c) 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 000000000001a62c 000000000000bf60 0000000000000000 00000000000003c0 0000000000000000 0000000000000080 000000000002322d 000000007f29ef20 0000000000efd018 000000000311c000 0000000000010070 0000000000012f82 000000000000bea8 Call Trace: (sp:000000000000bea8 [<000000000002016e>] 000000000002016e) sp:000000000000bf18 [<0000000000012408>] startup_kernel+0x88/0x2fc sp:000000000000bf60 [<00000000000100c4>] startup_normal+0xb0/0xb0 Reviewed-by: Alexander Egorenkov Signed-off-by: Vasily Gorbik Signed-off-by: Heiko Carstens --- arch/s390/boot/pgm_check_info.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'arch/s390/boot/pgm_check_info.c') diff --git a/arch/s390/boot/pgm_check_info.c b/arch/s390/boot/pgm_check_info.c index 8ba8136adb4d..d8bfc5673956 100644 --- a/arch/s390/boot/pgm_check_info.c +++ b/arch/s390/boot/pgm_check_info.c @@ -2,6 +2,7 @@ #include #include #include +#include #include #include #include @@ -121,6 +122,27 @@ out: sclp_early_printk(buf); } +static noinline void print_stacktrace(void) +{ + struct stack_info boot_stack = { STACK_TYPE_TASK, BOOT_STACK_OFFSET, + BOOT_STACK_OFFSET + BOOT_STACK_SIZE }; + unsigned long sp = S390_lowcore.gpregs_save_area[15]; + bool first = true; + + decompressor_printk("Call Trace:\n"); + while (!(sp & 0x7) && on_stack(&boot_stack, sp, sizeof(struct stack_frame))) { + struct stack_frame *sf = (struct stack_frame *)sp; + + decompressor_printk(first ? "(sp:%016lx [<%016lx>] %pS)\n" : + " sp:%016lx [<%016lx>] %pS\n", + sp, sf->gprs[8], (void *)sf->gprs[8]); + if (sf->back_chain <= sp) + break; + sp = sf->back_chain; + first = false; + } +} + void print_pgm_check_info(void) { unsigned long *gpregs = (unsigned long *)S390_lowcore.gpregs_save_area; @@ -148,4 +170,5 @@ void print_pgm_check_info(void) gpregs[8], gpregs[9], gpregs[10], gpregs[11]); decompressor_printk(" %016lx %016lx %016lx %016lx\n", gpregs[12], gpregs[13], gpregs[14], gpregs[15]); + print_stacktrace(); } -- cgit v1.2.3