fix(DiskIO): fix readlink

[apocelipes]

No description provided.

[CarterLi]

You fix what?

[apocelipes]

char pathSysDeviceReal[PATH_MAX] = "";

equals to

char pathSysDeviceReal[PATH_MAX];
pathSysDeviceReal = 0;

and the manpages said:

readlink() does not append a null byte to buf.

So, if readlink success, we got a invalid Null-terminated string.

[apocelipes]

Or, if use this:

char pathSysDeviceReal[PATH_MAX] = { '\0' };

It will zero-filled by memset or other functions. Since PATH_MAX on some Linux distros are set to 4096, it could be a noticeable cost.

[CarterLi]

In https://www.open-std.org/jtc1/sc22/wg14/www/docs/n1124.pdf, Page 127

[apocelipes]

In https://www.open-std.org/jtc1/sc22/wg14/www/docs/n1124.pdf, Page 127

This since C11, this project using C11, so, it will be zero-filled, and in most cases it's unnecessary.

[CarterLi]

This since C11

Citation needed

[CarterLi]

And even if you want to "fix" this, the same code in physical_linux.c (committed today) should be fixed too.

[CarterLi]

Please be cautious when using words like "bug" and "fix"

[apocelipes]

This since C11

Citation needed

It's my miss, C99 said the same thing at 6.7.8-21, some old unix's CCs confuse me with their implement behaviors.

[apocelipes]

Please be cautious when using words like "bug" and "fix"

Thank u, I see.