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

From: hpa
Date: Wed Feb 01 2017 - 20:39:46 EST

On January 31, 2017 10:52:11 AM PST, Nicolas Iooss <nicolas.iooss_linux@xxxxxxx> wrote:
>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);
>>

Both are wrong... either PRIu64 or add a cast.
--
Sent from my Android device with K-9 Mail. Please excuse my brevity.