Re: [PATCH v7 01/10] livepatch: Create and include UAPI headers

[Marcos Paulo de Souza]

On Mon, Mar 06, 2023 at 09:08:15AM -0500, Joe Lawrence wrote:
> Define klp prefixes in include/uapi/linux/livepatch.h, and use them for
> replacing hard-coded values in kernel/livepatch/core.c.
> 
> Update MAINTAINERS.
> 
> Note: Add defines to uapi as these are also to be used by a newly
> introduced klp-convert script.
> 
> Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> Signed-off-by: Joao Moreira <jmoreira@xxxxxxx>
> Signed-off-by: Joe Lawrence <joe.lawrence@xxxxxxxxxx>

LGTM:

Reviewed-by: Marcos Paulo de Souza <mpdesouza@xxxxxxxx>

> ---
>  MAINTAINERS                    |  1 +
>  include/linux/livepatch.h      |  1 +
>  include/uapi/linux/livepatch.h | 15 +++++++++++++++
>  kernel/livepatch/core.c        |  4 ++--
>  4 files changed, 19 insertions(+), 2 deletions(-)
>  create mode 100644 include/uapi/linux/livepatch.h
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 135d93368d36..5bdf333fb1f3 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -12069,6 +12069,7 @@ F:	Documentation/ABI/testing/sysfs-kernel-livepatch
>  F:	Documentation/livepatch/
>  F:	arch/powerpc/include/asm/livepatch.h
>  F:	include/linux/livepatch.h
> +F:	include/uapi/linux/livepatch.h
>  F:	kernel/livepatch/
>  F:	kernel/module/livepatch.c
>  F:	lib/livepatch/
> diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h
> index 293e29960c6e..46da4c0df6c1 100644
> --- a/include/linux/livepatch.h
> +++ b/include/linux/livepatch.h
> @@ -13,6 +13,7 @@
>  #include <linux/ftrace.h>
>  #include <linux/completion.h>
>  #include <linux/list.h>
> +#include <uapi/linux/livepatch.h>
>  
>  #if IS_ENABLED(CONFIG_LIVEPATCH)
>  
> diff --git a/include/uapi/linux/livepatch.h b/include/uapi/linux/livepatch.h
> new file mode 100644
> index 000000000000..e19430918a07
> --- /dev/null
> +++ b/include/uapi/linux/livepatch.h
> @@ -0,0 +1,15 @@
> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> +
> +/*
> + * livepatch.h - Kernel Live Patching Core
> + *
> + * Copyright (C) 2016 Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> + */
> +
> +#ifndef _UAPI_LIVEPATCH_H
> +#define _UAPI_LIVEPATCH_H
> +
> +#define KLP_RELA_PREFIX		".klp.rela."
> +#define KLP_SYM_PREFIX		".klp.sym."
> +
> +#endif /* _UAPI_LIVEPATCH_H */
> diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
> index 201f0c0482fb..c565d33db582 100644
> --- a/kernel/livepatch/core.c
> +++ b/kernel/livepatch/core.c
> @@ -234,7 +234,7 @@ static int klp_resolve_symbols(Elf_Shdr *sechdrs, const char *strtab,
>  
>  		/* Format: .klp.sym.sym_objname.sym_name,sympos */
>  		cnt = sscanf(strtab + sym->st_name,
> -			     ".klp.sym.%55[^.].%511[^,],%lu",
> +			     KLP_SYM_PREFIX "%55[^.].%511[^,],%lu",
>  			     sym_objname, sym_name, &sympos);
>  		if (cnt != 3) {
>  			pr_err("symbol %s has an incorrectly formatted name\n",
> @@ -305,7 +305,7 @@ int klp_apply_section_relocs(struct module *pmod, Elf_Shdr *sechdrs,
>  	 * See comment in klp_resolve_symbols() for an explanation
>  	 * of the selected field width value.
>  	 */
> -	cnt = sscanf(shstrtab + sec->sh_name, ".klp.rela.%55[^.]",
> +	cnt = sscanf(shstrtab + sec->sh_name, KLP_RELA_PREFIX "%55[^.]",
>  		     sec_objname);
>  	if (cnt != 1) {
>  		pr_err("section %s has an incorrectly formatted name\n",
> -- 
> 2.39.2
>