Memory corruption due to word sharing

[DJ Delorie]

Jan Kara <jack@suse.cz> writes:
>   we've spotted the following mismatch between what kernel folks expect
> from a compiler and what GCC really does, resulting in memory corruption on
> some architectures. Consider the following structure:
> struct x {
>     long a;
>     unsigned int b1;
>     unsigned int b2:1;
> };

If this structure were volatile, you could try
-fstrict-volatile-bitfields, which forces GCC to use the C type to
define the access width, instead of doing whatever it thinks is optimal.

Note: that flag is enabled by default for some targets already, most
notably ARM.