Re: [PATCH v3 1/1] x86, relocs: add printf attribute to die()

[Nicolas Iooss]

Hello,

As I have not received any comment on the patch I sent in December, I am
wondering whether I did anything wrong with it. How can I get it queued
for the next merge window?

Thanks,
Nicolas

On 18/12/16 20:47, Nicolas Iooss wrote:
> Adding such an attribute helps to detect errors in the format string at
> build time. After doing this, the compiler complains about such issues:
> 
>     arch/x86/tools/relocs.c:460:5: error: format specifies type 'int'
>     but the argument has type 'Elf64_Xword' (aka 'unsigned long')
>     [-Werror,-Wformat]
>                                     sec->shdr.sh_size);
>                                     ^~~~~~~~~~~~~~~~~
>     arch/x86/tools/relocs.c:464:5: error: format specifies type 'int'
>     but the argument has type 'Elf64_Off' (aka 'unsigned long')
>     [-Werror,-Wformat]
>                                     sec->shdr.sh_offset, strerror(errno));
>                                     ^~~~~~~~~~~~~~~~~~~
> 
> When relocs.c is included by relocs_32.c, sec->shdr.sh_size and
> sec->shdr.sh_offset are 32-bit unsigned integers. When the file is
> included by relocs_64.c, these expressions are 64-bit unsigned integers.
> 
> Introduce a PRIuELF macro to define the right format to use when
> printing sh_size and sh_offset values.
> 
> While at it, constify the format attribute of die().
> 
> Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@xxxxxxx>
> ---
> I sent the first versions of this patch in September (cf.
> https://patchwork.kernel.org/patch/9312665/) but it has not been
> applied.
> 
> As commit adee8705d251 ("x86/build: Annotate die() with noreturn to fix
> build warning on clang") introduced the noreturn attribute to die(),
> this patch now only adds the printf attribute.
> 
>  arch/x86/tools/relocs.c        | 14 +++++++-------
>  arch/x86/tools/relocs.h        |  3 ++-
>  arch/x86/tools/relocs_32.c     |  3 +++
>  arch/x86/tools/relocs_64.c     |  3 +++
>  arch/x86/tools/relocs_common.c |  2 +-
>  5 files changed, 16 insertions(+), 9 deletions(-)
> 
> diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
> index 0c2fae8d929d..4cad603b8d58 100644
> --- a/arch/x86/tools/relocs.c
> +++ b/arch/x86/tools/relocs.c
> @@ -397,7 +397,7 @@ static void read_shdrs(FILE *fp)
>  		    ehdr.e_shnum);
>  	}
>  	if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0) {
> -		die("Seek to %d failed: %s\n",
> +		die("Seek to %"PRIuELF" failed: %s\n",
>  			ehdr.e_shoff, strerror(errno));
>  	}
>  	for (i = 0; i < ehdr.e_shnum; i++) {
> @@ -431,11 +431,11 @@ static void read_strtabs(FILE *fp)
>  		}
>  		sec->strtab = malloc(sec->shdr.sh_size);
>  		if (!sec->strtab) {
> -			die("malloc of %d bytes for strtab failed\n",
> +			die("malloc of %"PRIuELF" bytes for strtab failed\n",
>  				sec->shdr.sh_size);
>  		}
>  		if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
> -			die("Seek to %d failed: %s\n",
> +			die("Seek to %"PRIuELF" failed: %s\n",
>  				sec->shdr.sh_offset, strerror(errno));
>  		}
>  		if (fread(sec->strtab, 1, sec->shdr.sh_size, fp)
> @@ -456,11 +456,11 @@ static void read_symtabs(FILE *fp)
>  		}
>  		sec->symtab = malloc(sec->shdr.sh_size);
>  		if (!sec->symtab) {
> -			die("malloc of %d bytes for symtab failed\n",
> +			die("malloc of %"PRIuELF" bytes for symtab failed\n",
>  				sec->shdr.sh_size);
>  		}
>  		if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
> -			die("Seek to %d failed: %s\n",
> +			die("Seek to %"PRIuELF" failed: %s\n",
>  				sec->shdr.sh_offset, strerror(errno));
>  		}
>  		if (fread(sec->symtab, 1, sec->shdr.sh_size, fp)
> @@ -489,11 +489,11 @@ static void read_relocs(FILE *fp)
>  		}
>  		sec->reltab = malloc(sec->shdr.sh_size);
>  		if (!sec->reltab) {
> -			die("malloc of %d bytes for relocs failed\n",
> +			die("malloc of %"PRIuELF" bytes for relocs failed\n",
>  				sec->shdr.sh_size);
>  		}
>  		if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
> -			die("Seek to %d failed: %s\n",
> +			die("Seek to %"PRIuELF" failed: %s\n",
>  				sec->shdr.sh_offset, strerror(errno));
>  		}
>  		if (fread(sec->reltab, 1, sec->shdr.sh_size, fp)
> diff --git a/arch/x86/tools/relocs.h b/arch/x86/tools/relocs.h
> index 1d23bf953a4a..f41416c31608 100644
> --- a/arch/x86/tools/relocs.h
> +++ b/arch/x86/tools/relocs.h
> @@ -16,7 +16,8 @@
>  #include <regex.h>
>  #include <tools/le_byteshift.h>
>  
> -void die(char *fmt, ...) __attribute__((noreturn));
> +void die(const char *fmt, ...) __attribute__((noreturn))
> +	__attribute__((format(printf, 1, 2)));
>  
>  #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
>  
> diff --git a/arch/x86/tools/relocs_32.c b/arch/x86/tools/relocs_32.c
> index b2ade2bb4162..8024ec473e6a 100644
> --- a/arch/x86/tools/relocs_32.c
> +++ b/arch/x86/tools/relocs_32.c
> @@ -14,4 +14,7 @@
>  #define ELF_ST_BIND(o)		ELF32_ST_BIND(o)
>  #define ELF_ST_VISIBILITY(o)	ELF32_ST_VISIBILITY(o)
>  
> +/* printf format for Elf32_Off */
> +#define PRIuELF PRIu32
> +
>  #include "relocs.c"
> diff --git a/arch/x86/tools/relocs_64.c b/arch/x86/tools/relocs_64.c
> index 56b61b743c4c..2cf4de5c9d99 100644
> --- a/arch/x86/tools/relocs_64.c
> +++ b/arch/x86/tools/relocs_64.c
> @@ -14,4 +14,7 @@
>  #define ELF_ST_BIND(o)          ELF64_ST_BIND(o)
>  #define ELF_ST_VISIBILITY(o)    ELF64_ST_VISIBILITY(o)
>  
> +/* printf format for Elf64_Off */
> +#define PRIuELF PRIu64
> +
>  #include "relocs.c"
> diff --git a/arch/x86/tools/relocs_common.c b/arch/x86/tools/relocs_common.c
> index acab636bcb34..30adb44eff79 100644
> --- a/arch/x86/tools/relocs_common.c
> +++ b/arch/x86/tools/relocs_common.c
> @@ -1,6 +1,6 @@
>  #include "relocs.h"
>  
> -void die(char *fmt, ...)
> +void die(const char *fmt, ...)
>  {
>  	va_list ap;
>  	va_start(ap, fmt);
>