[PATCH v3 04/26] bfd/elf-attrs.c: use ASCII character '(0x27) for single quote

[Matthieu Longo]

On 2025-06-11 10:23, Richard Earnshaw (lists) wrote:
> On 09/05/2025 16:12, Matthieu Longo wrote:
>> ---
>>   bfd/elf-attrs.c | 6 +++---
>>   1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/bfd/elf-attrs.c b/bfd/elf-attrs.c
>> index bc653d780de..b4a57f4803c 100644
>> --- a/bfd/elf-attrs.c
>> +++ b/bfd/elf-attrs.c
>> @@ -104,7 +104,7 @@ vendor_obj_attrs_v1_size (bfd *abfd, int vendor)
>>          list = list->next)
>>       size += obj_attr_v1_size (list->tag, &list->attr);
>>   
>> -  /* <size> <vendor_name> NUL 0x1 <size> */
>> +  /* <size> <vendor_name> NUL 0x1 <size>  */
>>     return (size
>>   	  ? size + 10 + strlen (vendor_name)
>>   	  : 0);
>> @@ -117,7 +117,7 @@ bfd_elf_obj_attrs_v1_size (bfd *abfd)
>>     size = vendor_obj_attrs_v1_size (abfd, OBJ_ATTR_PROC);
>>     size += vendor_obj_attrs_v1_size (abfd, OBJ_ATTR_GNU);
>>     if (size > 0)
>> -    size += sizeof(uint8_t); /* <format-version: ‘A’>  */
>> +    size += sizeof(uint8_t); /* <format-version: 'A'>  */
>>     return size;
>>   }
>>   
>> @@ -212,7 +212,7 @@ write_obj_attr_section_v1 (bfd *abfd, bfd_byte *buffer, bfd_vma size)
>>   {
>>     bfd_byte *p = buffer;
>>   
>> -  /* <format-version: ‘A’>  */
>> +  /* <format-version: 'A'>  */
>>     *(p++) = 'A';
>>   
>>     for (int vendor = OBJ_ATTR_FIRST; vendor <= OBJ_ATTR_LAST; ++vendor)
> 
> I can't approve this patch (or reject it), but I do wonder why you think it's needed.  There's nothing in the commit message to give justification for it's need.
> 
> R.

The previous discussion was here: 
https://inbox.sourceware.org/binutils/72219ed1-147d-4dd3-b503-363d981528a2@arm.com/

I forgot to update the commit message.
Please let me know if this description is good enough.

Commit title:
Remove non-ASCII characters causing false positive security warnings

Description:
Arm's internal review tool complains about diffs containing non-ASCII 
characters. The message points to a security risk explained in [1] and 
[2]. The warnings from the review tool are a reasonable protection 
against a potential avenue of surreptitious source code alteration, 
relying on the usage of confusable Unicode characters. Instances that 
are generating false positives should be removed, unless the presence of 
such characters is necessary for the job at hand.

Even if the usage of curly simple quote seems legitimate and not 
confusing, the cost of supporting it in comparison of the cost of 
removing the false positive does not tip the scale in favor of the first 
option.

This patch removes the curly simple quotes in bfd/elf-attrs.c, and 
replaces them with a single quote ASCII character (0x27).

[1]: LWN article: https://lwn.net/Articles/874951/
[2]: Associated paper: https://trojansource.codes/trojan-source.pdf