On 07/05/2020 14:22, Jan Beulich wrote: > On 02.05.2020 00:58, Andrew Cooper wrote: >> @@ -114,6 +114,16 @@ >> sub $1, %ecx >> jnz .L\@_fill_rsb_loop >> mov %\tmp, %rsp /* Restore old %rsp */ >> + >> +#ifdef CONFIG_XEN_SHSTK >> + mov $1, %ecx >> + rdsspd %ecx >> + cmp $1, %ecx >> + je .L\@_shstk_done >> + mov $64, %ecx /* 64 * 4 bytes, given incsspd */ >> + incsspd %ecx /* Restore old SSP */ >> +.L\@_shstk_done: >> +#endif > The latest here I wonder why you don't use alternatives patching. > I thought that's what you've introduced the synthetic feature > flag for.
We're already in the middle of an alternative and they don't nest. More importantly, this path gets used on the BSP, after patching and before CET gets enabled. ~Andrew
