Messages in this thread Patch in this message | | | Date | Wed, 22 Apr 2020 12:23:09 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH v2] x86: fix early boot crash on gcc-10 |
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Ok,
let's try the simple and clean fix first. Nick, would that work on LLVM too?
And I hope this will remain working and the compiler won't jump over an inline asm and go nuts.
Thx.
--- diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 3b9bf8c7e29d..06d2e16bedbb 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -266,6 +266,13 @@ static void notrace start_secondary(void *unused) wmb(); cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); + + /* + * Prevent tail call to cpu_startup_entry() because the stack protector + * guard has been changed in the middle of this function and must not be + * checked before tail calling another function. + */ + asm (""); } /** -- Regards/Gruss, Boris.
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