On 2017/8/26 5:13, Thomas Gleixner wrote: > On Fri, 25 Aug 2017, zhong jiang wrote: >> From: zhong jiang <zhongjiang@xxxxxxxxxx> >> Date: Fri, 25 Aug 2017 12:05:56 +0800 >> Subject: [PATCH v2] futex: avoid undefined behaviour when shift exponent is >> negative > Please do not send patches without changing the subject line so it's clear > that there is a new patch. ok >> using a shift value < 0 or > 31 will get crap as a result. because >> it's just undefined. The issue still disturb me, so I try to fix >> it again by excluding the especially condition. > Which is obsolete now as this code is unified accross all architectures and > the shift issue is addressed in the generic version of it. So all > architectures get the same fix. See: > > http://git.kernel.org/tip/30d6e0a4190d37740e9447e4e4815f06992dd8c3 ok , I miss the above patch. > And no, we won't add that x86 fix before that unification hits mainline > because that undefined behaviour is harmless as it only affects the user > space value of the futex. IOW, the caller gets what it asked for: crap. Thank you for clarification. Regards zhongjiang > Thanks, > > tglx > > > . > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>