Re: [PATCH v2 6/9] s390/module: Use s390_kernel_write() for late relocations

[Miroslav Benes]

> +int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
> +		       unsigned int symindex, unsigned int relsec,
> +		       struct module *me)
> +{
> +	int ret;
> +	bool early = me->state == MODULE_STATE_UNFORMED;
> +	void *(*write)(void *, const void *, size_t) = memcpy;
> +
> +	if (!early) {
> +		write = s390_kernel_write;
> +		mutex_lock(&text_mutex);
> +	}
> +
> +	ret = __apply_relocate_add(sechdrs, strtab, symindex, relsec, me,
> +				   write);
> +
> +	if (!early)
> +		mutex_unlock(&text_mutex);
> +
> +	return ret;
> +}

It means that you can take text_mutex the second time here because it 
is still taken in klp_init_object_loaded(). It is removed later in the 
series though. The same applies for x86 patch.

Also, s390_kernel_write() grabs s390_kernel_write_lock spinlock before 
writing anything, so maybe text_mutex is not really needed as long as 
s390_kernel_write is called everywhere for text patching.

Miroslav