Subject: Re: linux-next: manual merge of the tip tree with the powerpc-objtool tree

From: Stephen Rothwell <[email-masked]>
Date: Fri, 16 Dec 2022 10:09:05 +1100

Hi all,

On Thu, 24 Nov 2022 12:29:31 +1100 Stephen Rothwell <[email-masked]> wrote:
> 
> Today's linux-next merge of the tip tree got a conflict in:
> 
>   tools/objtool/check.c
> 
> between commit:
> 
>   efb11fdb3e1a ("objtool: Fix SEGFAULT")
> 
> from the powerpc-objtool tree and commit:
> 
>   dbcdbdfdf137 ("objtool: Rework instruction -> symbol mapping")
> 
> from the tip tree.
> 
> I fixed it up (see below) and can carry the fix as necessary. This
> is now fixed as far as linux-next is concerned, but any non trivial
> conflicts should be mentioned to your upstream maintainer when your tree
> is submitted for merging.  You may also want to consider cooperating
> with the maintainer of the conflicting tree to minimise any particularly
> complex conflicts.
> 
> -- 
> Cheers,
> Stephen Rothwell
> 
> diff --cc tools/objtool/check.c
> index 7580c66ca5c8,4f1a7384426b..000000000000
> --- a/tools/objtool/check.c
> +++ b/tools/objtool/check.c
> @@@ -207,7 -204,7 +204,7 @@@ static bool __dead_end_function(struct 
>   		return false;
>   
>   	insn = find_insn(file, func->sec, func->offset);
> - 	if (!insn || !insn->func)
>  -	if (!insn_func(insn))
> ++	if (!insn || !insn_func(insn))
>   		return false;
>   
>   	func_for_each_insn(file, func, insn) {
> @@@ -850,11 -861,73 +861,73 @@@ static int create_ibt_endbr_seal_sectio
>   	return 0;
>   }
>   
> + static int create_cfi_sections(struct objtool_file *file)
> + {
> + 	struct section *sec, *s;
> + 	struct symbol *sym;
> + 	unsigned int *loc;
> + 	int idx;
> + 
> + 	sec = find_section_by_name(file->elf, ".cfi_sites");
> + 	if (sec) {
> + 		INIT_LIST_HEAD(&file->call_list);
> + 		WARN("file already has .cfi_sites section, skipping");
> + 		return 0;
> + 	}
> + 
> + 	idx = 0;
> + 	for_each_sec(file, s) {
> + 		if (!s->text)
> + 			continue;
> + 
> + 		list_for_each_entry(sym, &s->symbol_list, list) {
> + 			if (sym->type != STT_FUNC)
> + 				continue;
> + 
> + 			if (strncmp(sym->name, "__cfi_", 6))
> + 				continue;
> + 
> + 			idx++;
> + 		}
> + 	}
> + 
> + 	sec = elf_create_section(file->elf, ".cfi_sites", 0, sizeof(unsigned int), idx);
> + 	if (!sec)
> + 		return -1;
> + 
> + 	idx = 0;
> + 	for_each_sec(file, s) {
> + 		if (!s->text)
> + 			continue;
> + 
> + 		list_for_each_entry(sym, &s->symbol_list, list) {
> + 			if (sym->type != STT_FUNC)
> + 				continue;
> + 
> + 			if (strncmp(sym->name, "__cfi_", 6))
> + 				continue;
> + 
> + 			loc = (unsigned int *)sec->data->d_buf + idx;
> + 			memset(loc, 0, sizeof(unsigned int));
> + 
> + 			if (elf_add_reloc_to_insn(file->elf, sec,
> + 						  idx * sizeof(unsigned int),
> + 						  R_X86_64_PC32,
> + 						  s, sym->offset))
> + 				return -1;
> + 
> + 			idx++;
> + 		}
> + 	}
> + 
> + 	return 0;
> + }
> + 
>   static int create_mcount_loc_sections(struct objtool_file *file)
>   {
>  -	struct section *sec;
>  -	unsigned long *loc;
>  +	int addrsize = elf_class_addrsize(file->elf);
>   	struct instruction *insn;
>  +	struct section *sec;
>   	int idx;
>   
>   	sec = find_section_by_name(file->elf, "__mcount_loc");

This is now a conflict between the powerpc tree and Linus' tree.

-- 
Cheers,
Stephen Rothwell