Created attachment 1522612 [details]
original file

gcc9 fails on this inline asm snippet in the kernel:

static inline bool arch_static_branch(struct static_key *key, bool branch)
{
        asm_volatile_goto("0:   brcl    0,"__stringify(JUMP_LABEL_NOP_OFFSET)"\n"
                          ".pushsection __jump_table,\"aw\"\n"
                          ".balign      8\n"
                          ".long        0b-.,%l[label]-.\n"
                          ".quad        %c0-.\n"
                          ".popsection\n"
                          : : "X" (&((char *)key)[branch]) : : label);
        return false;
label:
        return true;
}


BUILDSTDERR: ./arch/s390/include/asm/jump_label.h: Assembler messages:
BUILDSTDERR: ./arch/s390/include/asm/jump_label.h:23: Error: bad expression
BUILDSTDERR: ./arch/s390/include/asm/jump_label.h:23: Error: junk at end of line, first unrecognized character is `r'
BUILDSTDERR: make[1]: *** [scripts/Makefile.build:277: init/main.o] Error 1


This seems to be from this block:

static int __init initcall_blacklist(char *str)
{
        char *str_entry;
        struct blacklist_entry *entry;

        /* str argument is a comma-separated list of functions */
        do {
                str_entry = strsep(&str, ",");
                if (str_entry) {
                        pr_debug("blacklisting initcall %s\n", str_entry);
                        entry = memblock_alloc(sizeof(*entry),
                                               SMP_CACHE_BYTES);
                        entry->buf = memblock_alloc(strlen(str_entry) + 1,
                                                    SMP_CACHE_BYTES);
                        strcpy(entry->buf, str_entry);
                        list_add(&entry->next, &blacklisted_initcalls);
                }
        } while (str_entry);

        return 0;
}

specifically, the strsep. 

# 19 "./arch/s390/include/asm/jump_label.h" 1
        0:      brcl    0,2
.pushsection __jump_table,"aw"
.balign 8
.long   0b-.,.L249-.    #
.quad   %r10-.  # tmp98
.popsection


This looks like the bad assembly, it's generating a referenece to a register.