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charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 42A4D4000E X-Rspam-User: X-Rspamd-Server: rspam07 X-Stat-Signature: dn6k3yygiy5yti6jjrnnegtkk9zbpnkm X-HE-Tag: 1736867149-46208 X-HE-Meta: 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 t4KLiCQ/ d6Yj/OdL6ROx5jQxUfccXuMwWNKU6bY9CDIUQLwdpDXc3QO1SVDBgUWxPeu2rL/cONn3y0vrXmy1jy0eA3xKHpLGofFaTPRQ1Rith/mUqYXTrUJ51V50hx/YJnUPYX8wE0xUfOmphNaHL4ELmIcfbo3BYGIKIYnCLverLrrgeVVxnIUdsLf+f4Rd5UgjLB+LBoQFIPwzmthY6tqwxD0yWvII4xwC7yn+ROaWPXQzGalWxOSEVhyl3ih5z4uU8bIMaV/ziK4jvtWT3OmjrLUUWmHKHiw== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 1/14/25 06:29, Tom Lendacky wrote: >> Given the choice between "a bug in the calling code >> crashes the kernel" and "a bug in the calling code >> results in a missed TLB flush", I'm guessing the >> crash is probably better. > So instead of the negative number protection, shouldn't this just use an > unsigned int for extra_count and panic() if the value is greater than > invlpgb_count_max? The caller has some sort of logic problem and it > could possibly result in missed TLB flushes. Or if a panic() is out of > the question, maybe a WARN() and a full TLB flush to be safe? The current implementation will panic in the #GP handler though. It should be pretty easy to figure out that INVLPGB is involved with RIP or the Code: snippet. From there, you'd need to figure out what caused the #GP. I guess the one nasty thing is that a person debugging this might not have a CPUID dump handy so wouldn't actually know the number of valid addresses that INVLPGB can take. But otherwise, I'm not sure an explicit panic adds _much_ value here over an implicit one via the #GP handler. I don't know how everybody else feels about it, but I'm happy just depending on the #GP for now.