Re: [PATCH v4 01/10] objtool: Handle various symbol types of rodata

[Tiezhu Yang]

On 11/26/2024 02:44 PM, Josh Poimboeuf wrote:
> On Fri, Nov 22, 2024 at 12:49:56PM +0800, Tiezhu Yang wrote:
> > @@ -2094,12 +2095,19 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn,
> >  		if (prev_offset && reloc_offset(reloc) != prev_offset + 8)
> >  			break;
> >
> > +		if (reloc->sym->type == STT_SECTION) {
> > +			/* Addend field in the relocation entry associated with the symbol */
> > +			offset = reloc_addend(reloc);
> > +		} else {
> > +			/* The address of the symbol in the relocation entry */
> > +			offset = reloc->sym->offset;
>
> The comments don't seem helpful.

Will remove it.

> In the case of STT_SECTION, sym->offset is always zero.  Therefore the
> if-else can be converted to a simple unconditional statement:
>
> 	offset = reloc->sym->offset + reloc_addend(reloc);

OK, let me test it.

> 'prev_offset' needs to be updated as well.

I am not sure I understand your comment correctly, I can not see
what should to do about 'prev_offset'.

> > @@ -2137,6 +2145,7 @@ static struct reloc *find_jump_table(struct objtool_file *file,
> >  {
> >  	struct reloc *table_reloc;
> >  	struct instruction *dest_insn, *orig_insn = insn;
> > +	unsigned long offset;
> >
> >  	/*
> >  	 * Backward search using the @first_jump_src links, these help avoid
> > @@ -2160,7 +2169,16 @@ static struct reloc *find_jump_table(struct objtool_file *file,
> >  		table_reloc = arch_find_switch_table(file, insn);
> >  		if (!table_reloc)
> >  			continue;
> > -		dest_insn = find_insn(file, table_reloc->sym->sec, reloc_addend(table_reloc));
> > +
> > +		if (table_reloc->sym->type == STT_SECTION) {
> > +			/* Addend field in the relocation entry associated with the symbol */
> > +			offset = reloc_addend(table_reloc);
> > +		} else {
> > +			/* The address of the symbol in the relocation entry */
> > +			offset = table_reloc->sym->offset;
> > +		}
>
> Same comment here.

OK, will do it.

Thanks,
Tiezhu