Re: [PATCH v2 01/13] livepatch: Fix build failure on 32 bits processors

On Mon, 20 Dec 2021, Christophe Leroy wrote:

Trying to build livepatch on powerpc/32 results in:

	kernel/livepatch/core.c: In function 'klp_resolve_symbols':
	kernel/livepatch/core.c:221:23: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
	  221 |                 sym = (Elf64_Sym *)sechdrs[symndx].sh_addr + ELF_R_SYM(relas[i].r_info);
	      |                       ^
	kernel/livepatch/core.c:221:21: error: assignment to 'Elf32_Sym *' {aka 'struct elf32_sym *'} from incompatible pointer type 'Elf64_Sym *' {aka 'struct elf64_sym *'} [-Werror=incompatible-pointer-types]
	  221 |                 sym = (Elf64_Sym *)sechdrs[symndx].sh_addr + ELF_R_SYM(relas[i].r_info);
	      |                     ^
	kernel/livepatch/core.c: In function 'klp_apply_section_relocs':
	kernel/livepatch/core.c:312:35: error: passing argument 1 of 'klp_resolve_symbols' from incompatible pointer type [-Werror=incompatible-pointer-types]
	  312 |         ret = klp_resolve_symbols(sechdrs, strtab, symndx, sec, sec_objname);
	      |                                   ^~~~~~~
	      |                                   |
	      |                                   Elf32_Shdr * {aka struct elf32_shdr *}
	kernel/livepatch/core.c:193:44: note: expected 'Elf64_Shdr *' {aka 'struct elf64_shdr *'} but argument is of type 'Elf32_Shdr *' {aka 'struct elf32_shdr *'}
	  193 | static int klp_resolve_symbols(Elf64_Shdr *sechdrs, const char *strtab,
	      |                                ~~~~~~~~~~~~^~~~~~~

Fix it by using the right types instead of forcing 64 bits types.

Fixes: 7c8e2bdd5f0d ("livepatch: Apply vmlinux-specific KLP relocations early")
Signed-off-by: Christophe Leroy <redacted>
Acked-by: Petr Mladek <pmladek@suse.com>

Acked-by: Miroslav Benes <mbenes@suse.cz>

M