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Groups > linux.kernel > #1592774 > unrolled thread
| Started by | Nicolas Iooss <nicolas.iooss_linux@m4x.org> |
|---|---|
| First post | 2017-03-05 15:40 +0100 |
| Last post | 2017-03-07 20:20 +0100 |
| Articles | 3 — 2 participants |
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[PATCH v4 1/1] x86, relocs: add printf attribute to die() Nicolas Iooss <nicolas.iooss_linux@m4x.org> - 2017-03-05 15:40 +0100
Re: [PATCH v4 1/1] x86, relocs: add printf attribute to die() Ingo Molnar <mingo@kernel.org> - 2017-03-07 14:30 +0100
Re: [PATCH v4 1/1] x86, relocs: add printf attribute to die() Nicolas Iooss <nicolas.iooss_linux@m4x.org> - 2017-03-07 20:20 +0100
| From | Nicolas Iooss <nicolas.iooss_linux@m4x.org> |
|---|---|
| Date | 2017-03-05 15:40 +0100 |
| Subject | [PATCH v4 1/1] x86, relocs: add printf attribute to die() |
| Message-ID | <thFuh-1BG-5@gated-at.bofh.it> |
Adding such an attribute helps to detect errors in the format string at
build time. After doing this, the compiler complains about some 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.
Add casts to unsigned long long, which length is always 64-bit, and use
%llu to format sec->shdr.sh_size and sec->shdr.sh_offset in relocs.c.
While at it, constify the format attribute of die().
Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
---
arch/x86/tools/relocs.c | 31 +++++++++++++++++--------------
arch/x86/tools/relocs.h | 3 ++-
arch/x86/tools/relocs_common.c | 2 +-
3 files changed, 20 insertions(+), 16 deletions(-)
diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
index 73eb7fd4aec4..3cc02065c677 100644
--- a/arch/x86/tools/relocs.c
+++ b/arch/x86/tools/relocs.c
@@ -397,8 +397,8 @@ 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",
- ehdr.e_shoff, strerror(errno));
+ die("Seek to %llu failed: %s\n",
+ (unsigned long long)ehdr.e_shoff, strerror(errno));
}
for (i = 0; i < ehdr.e_shnum; i++) {
struct section *sec = &secs[i];
@@ -431,12 +431,13 @@ 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",
- sec->shdr.sh_size);
+ die("malloc of %llu bytes for strtab failed\n",
+ (unsigned long long)sec->shdr.sh_size);
}
if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
- die("Seek to %d failed: %s\n",
- sec->shdr.sh_offset, strerror(errno));
+ die("Seek to %llu failed: %s\n",
+ (unsigned long long)sec->shdr.sh_offset,
+ strerror(errno));
}
if (fread(sec->strtab, 1, sec->shdr.sh_size, fp)
!= sec->shdr.sh_size) {
@@ -456,12 +457,13 @@ 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",
- sec->shdr.sh_size);
+ die("malloc of %llu bytes for symtab failed\n",
+ (unsigned long long)sec->shdr.sh_size);
}
if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
- die("Seek to %d failed: %s\n",
- sec->shdr.sh_offset, strerror(errno));
+ die("Seek to %llu failed: %s\n",
+ (unsigned long long)sec->shdr.sh_offset,
+ strerror(errno));
}
if (fread(sec->symtab, 1, sec->shdr.sh_size, fp)
!= sec->shdr.sh_size) {
@@ -489,12 +491,13 @@ 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",
- sec->shdr.sh_size);
+ die("malloc of %llu bytes for relocs failed\n",
+ (unsigned long long)sec->shdr.sh_size);
}
if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
- die("Seek to %d failed: %s\n",
- sec->shdr.sh_offset, strerror(errno));
+ die("Seek to %llu failed: %s\n",
+ (unsigned long long)sec->shdr.sh_offset,
+ strerror(errno));
}
if (fread(sec->reltab, 1, sec->shdr.sh_size, fp)
!= sec->shdr.sh_size) {
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_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);
--
2.11.1
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| From | Ingo Molnar <mingo@kernel.org> |
|---|---|
| Date | 2017-03-07 14:30 +0100 |
| Message-ID | <tinlE-83G-13@gated-at.bofh.it> |
| In reply to | #1592774 |
* Nicolas Iooss <nicolas.iooss_linux@m4x.org> wrote:
> Adding such an attribute helps to detect errors in the format string at
> build time. After doing this, the compiler complains about some 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.
>
> Add casts to unsigned long long, which length is always 64-bit, and use
> %llu to format sec->shdr.sh_size and sec->shdr.sh_offset in relocs.c.
>
> While at it, constify the format attribute of die().
>
> Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
> ---
> arch/x86/tools/relocs.c | 31 +++++++++++++++++--------------
> arch/x86/tools/relocs.h | 3 ++-
> arch/x86/tools/relocs_common.c | 2 +-
> 3 files changed, 20 insertions(+), 16 deletions(-)
>
> diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
> index 73eb7fd4aec4..3cc02065c677 100644
> --- a/arch/x86/tools/relocs.c
> +++ b/arch/x86/tools/relocs.c
> @@ -397,8 +397,8 @@ 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",
> - ehdr.e_shoff, strerror(errno));
> + die("Seek to %llu failed: %s\n",
> + (unsigned long long)ehdr.e_shoff, strerror(errno));
Isn't "(u64)" shorter to write?
Thanks,
Ingo
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| From | Nicolas Iooss <nicolas.iooss_linux@m4x.org> |
|---|---|
| Date | 2017-03-07 20:20 +0100 |
| Message-ID | <tisOm-3ze-25@gated-at.bofh.it> |
| In reply to | #1594238 |
On Tue, Mar 7, 2017 at 10:16 AM, Ingo Molnar <mingo@kernel.org> wrote:
>
> * Nicolas Iooss <nicolas.iooss_linux@m4x.org> wrote:
>
>> Adding such an attribute helps to detect errors in the format string at
>> build time. After doing this, the compiler complains about some 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.
>>
>> Add casts to unsigned long long, which length is always 64-bit, and use
>> %llu to format sec->shdr.sh_size and sec->shdr.sh_offset in relocs.c.
>>
>> While at it, constify the format attribute of die().
>>
>> Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
>> ---
>> arch/x86/tools/relocs.c | 31 +++++++++++++++++--------------
>> arch/x86/tools/relocs.h | 3 ++-
>> arch/x86/tools/relocs_common.c | 2 +-
>> 3 files changed, 20 insertions(+), 16 deletions(-)
>>
>> diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
>> index 73eb7fd4aec4..3cc02065c677 100644
>> --- a/arch/x86/tools/relocs.c
>> +++ b/arch/x86/tools/relocs.c
>> @@ -397,8 +397,8 @@ 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",
>> - ehdr.e_shoff, strerror(errno));
>> + die("Seek to %llu failed: %s\n",
>> + (unsigned long long)ehdr.e_shoff, strerror(errno));
>
> Isn't "(u64)" shorter to write?
u64 does not seem to be defined in this file right now. Adding
"#include <linux/types.h>" defines u64 and __u64 in the following way:
- "typedef uint64_t u64;" from tools/include/linux/types.h
- "typedef unsigned long long __u64;" from /usr/include/asm-generic/int-ll64.h
uint64_t is unsigned long on x86-64 and gcc complains when using %llu
on such a type, so using a cast to u64 forces using PRIu64 too.
Nevertheless "(__u64)" is shorter than "(unsigned long long)" and
seems to work fine in my quick tests because it is always unsigned
long long (on both x86-32 and x86-64). Would you prefer to use this
cast?
Thanks,
Nicolas
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