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x86/speculation: Use generic retpoline by default on AMD
authorKim Phillips <kim.phillips@amd.com>
Mon, 28 Feb 2022 17:23:15 +0000 (11:23 -0600)
committerBorislav Petkov <bp@suse.de>
Mon, 28 Feb 2022 17:37:08 +0000 (18:37 +0100)
commit244d00b5dd4755f8df892c86cab35fb2cfd4f14b
tree72eb087e1e58cc99734ce51e1fb022717eb3a129
parent44a3918c8245ab10c6c9719dd12e7a8d291980d8
x86/speculation: Use generic retpoline by default on AMD

AMD retpoline may be susceptible to speculation. The speculation
execution window for an incorrect indirect branch prediction using
LFENCE/JMP sequence may potentially be large enough to allow
exploitation using Spectre V2.

By default, don't use retpoline,lfence on AMD.  Instead, use the
generic retpoline.

Signed-off-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
arch/x86/kernel/cpu/bugs.c