Change Details

According to the description of SBSS issue at https://software.intel.com/content/www/us/en/develop/articles/software-security- guidance/technical-documentation/speculative-behavior-swapgs-and-segment-registe rs.html lfence after swapgs is needed only for the case when swapgs could be speculatively executed. Since syscall entry, unlike exception and interrupt entries, executes swapgs unconditionally, there is no opportunity for speculation.

According to the description of SBSS issue at https://software.intel.com/content/www/us/en/develop/articles/software-security-guidance/technical-documentation/speculative-behavior-swapgs-and-segment-registers.html lfence after swapgs is needed only for the case when swapgs could be speculatively executed. Since syscall entry, unlike exception and interrupt entries, executes swapgs unconditionally, there is no opportunity for speculation.

According to the description of SBSS issue at https://software.intel.com/content/www/us/en/develop/articles/software-security- guidance/technical-documentation/speculative-behavior-swapgs-and-segment-registe rsrs.html lfence after swapgs is needed only for the case when swapgs could be speculatively executed. Since syscall entry, unlike exception and interrupt entries, executes swapgs unconditionally, there is no opportunity for speculation.