4 ms·
You can’t set FS/GS from user space on x64-64 until the FSGSBASE instructions were introduced in Ivy Bridge. The kernel only needs to be involved as its privile
by etaoins 8y ago
You can’t set FS/GS from user space on x64-64 until the FSGSBASE instructions were introduced in Ivy Bridge. The kernel only needs to be involved as its privilege is needed to set the register; the kernel doesn’t “know” that they’re being used for TLS.