x86/retpolines: Enable the default thunk warning only on relevant configs
authorBorislav Petkov (AMD) <bp@alien8.de>
Mon, 15 Apr 2024 16:15:43 +0000 (18:15 +0200)
committerBorislav Petkov (AMD) <bp@alien8.de>
Wed, 17 Apr 2024 16:02:05 +0000 (18:02 +0200)
commit6376306adde5b252ee7c73572e35d13fb13f6f18
treecf8dce67fa3fec89d162638ae8cb8ad379eea0f9
parent69129794d94c544810e68b2b4eaa7e44063f9bf2
x86/retpolines: Enable the default thunk warning only on relevant configs

The using-default-thunk warning check makes sense only with
configurations which actually enable the special return thunks.

Otherwise, it fires on unrelated 32-bit configs on which the special
return thunks won't even work (they're 64-bit only) and, what is more,
those configs even go off into the weeds when booting in the
alternatives patching code, leading to a dead machine.

Fixes: 4461438a8405 ("x86/retpoline: Ensure default return thunk isn't used at runtime")
Reported-by: Klara Modin <klarasmodin@gmail.com>
Reported-by: Erhard Furtner <erhard_f@mailbox.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Klara Modin <klarasmodin@gmail.com>
Link: https://lore.kernel.org/r/78e0d19c-b77a-4169-a80f-2eef91f4a1d6@gmail.com
Link: https://lore.kernel.org/r/20240413024956.488d474e@yea
arch/x86/lib/retpoline.S