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| author |   Lai Jiangshan <laijs@linux.alibaba.com> | 2021-11-26 18:11:22 +0800 |
|---|---|---|
| committer |   Borislav Petkov <bp@suse.de> | 2021-12-03 19:13:53 +0100 |
| commit | 1367afaa2ee90d1c956dfc224e199fcb3ff3f8cc (patch) | |
| tree | 19d948b14420f3ff5327c15adfea84543e7bd4d2 /arch/x86/xen/xen-asm.S | |
| parent | x86/entry: Add a fence for kernel entry SWAPGS in paranoid_entry() (diff) | |
| download | linux-dev-1367afaa2ee90d1c956dfc224e199fcb3ff3f8cc.tar.xz linux-dev-1367afaa2ee90d1c956dfc224e199fcb3ff3f8cc.zip | |
x86/entry: Use the correct fence macro after swapgs in kernel CR3
The commit
c75890700455 ("x86/entry/64: Remove unneeded kernel CR3 switching")
removed a CR3 write in the faulting path of load_gs_index().
But the path's FENCE_SWAPGS_USER_ENTRY has no fence operation if PTI is
enabled, see spectre_v1_select_mitigation().
Rather, it depended on the serializing CR3 write of SWITCH_TO_KERNEL_CR3
and since it got removed, add a FENCE_SWAPGS_KERNEL_ENTRY call to make
sure speculation is blocked.
[ bp: Massage commit message and comment. ]
Fixes: c75890700455 ("x86/entry/64: Remove unneeded kernel CR3 switching")
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20211126101209.8613-3-jiangshanlai@gmail.com
Diffstat (limited to '')
0 files changed, 0 insertions, 0 deletions