Patch "livepatch: Fix build failure on 32 bits processors" has been added to the 5.17-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    livepatch: Fix build failure on 32 bits processors

to the 5.17-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     livepatch-fix-build-failure-on-32-bits-processors.patch
and it can be found in the queue-5.17 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit ee5f21b6b2636c9bbdba168273d68a84081915d0
Author: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Date:   Mon Dec 20 16:38:02 2021 +0000

    livepatch: Fix build failure on 32 bits processors
    
    [ Upstream commit 2f293651eca3eacaeb56747dede31edace7329d2 ]
    
    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 <christophe.leroy@xxxxxxxxxx>
    Acked-by: Petr Mladek <pmladek@xxxxxxxx>
    Acked-by: Joe Lawrence <joe.lawrence@xxxxxxxxxx>
    Acked-by: Miroslav Benes <mbenes@xxxxxxx>
    Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
    Link: https://lore.kernel.org/r/5288e11b018a762ea3351cc8fb2d4f15093a4457.1640017960.git.christophe.leroy@xxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index 585494ec464f..bc475e62279d 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -190,7 +190,7 @@ static int klp_find_object_symbol(const char *objname, const char *name,
 	return -EINVAL;
 }
 
-static int klp_resolve_symbols(Elf64_Shdr *sechdrs, const char *strtab,
+static int klp_resolve_symbols(Elf_Shdr *sechdrs, const char *strtab,
 			       unsigned int symndx, Elf_Shdr *relasec,
 			       const char *sec_objname)
 {
@@ -218,7 +218,7 @@ static int klp_resolve_symbols(Elf64_Shdr *sechdrs, const char *strtab,
 	relas = (Elf_Rela *) relasec->sh_addr;
 	/* For each rela in this klp relocation section */
 	for (i = 0; i < relasec->sh_size / sizeof(Elf_Rela); i++) {
-		sym = (Elf64_Sym *)sechdrs[symndx].sh_addr + ELF_R_SYM(relas[i].r_info);
+		sym = (Elf_Sym *)sechdrs[symndx].sh_addr + ELF_R_SYM(relas[i].r_info);
 		if (sym->st_shndx != SHN_LIVEPATCH) {
 			pr_err("symbol %s is not marked as a livepatch symbol\n",
 			       strtab + sym->st_name);