Indeed, now that IBRS_FW also exists, grepping for just IBRS catches it where it shouldn't.
However, I don't get the <IBRS> fix, I don't see any occurence of <IBRS> in the (vanilla) source code, so I'm not sure where it comes from?

Under OpenSUSE it works, as you noticed, because they don't use the vanilla code here, and so they don't use the IBRS tag but the full "Indirect Branch Restricted Speculation" text in the spectre_v2 sysfs file.

Simply adding -w in the grep options should do the trick however, selecting IBRS without IBRS_FW. Can you modify your PR accordingly if this seems right for you too?

they don't use the vanilla code here,

There is no vanilla code for IBRS. It was never merged and most likely never will. Linus wants to push on Intel by this to fix it in their CPUs instead of slowing the code down AFAIU.

FYI currently, SUSE is in the process of dropping the patches from all their branches too.

I don't get the fix,

\<IBRS\> means whole word, the same as -w, but you use multiple -es on that line, so -w would apply to all of them.

they don't use the vanilla code here,

There is no vanilla code for IBRS. It was never merged and most likely never will. Linus wants to push on Intel by this to fix it in their CPUs instead of slowing the code down AFAIU.

I remember seeing several patches on the LKML floating around the days/weeks after the disclosure, but I'm not sure they were ever merged indeed, due to catastrophic performance on non-very-recent Intel CPUs. I think even Intel advised against it after things started to quiet down. The grep IBRS comes from those patches. I'll still leave it in case people run some custom kernel version with those.

FYI currently, SUSE is in the process of dropping the patches from all their branches too.

I don't get the fix,

\<IBRS\> means whole word, the same as -w, but you use multiple -es on that line, so -w would apply to all of them.

Never stumbled upon this syntax before, I think I'm too used to PCRE-style regexes! But it works as you say, including under BSD, so it's good for me.