Messages in this thread | | | Date | Wed, 30 Jun 2021 13:47:08 +0200 (CEST) | From | Miroslav Benes <> | Subject | Re: [PATCH v2 01/24] x86/xen: Mark cpu_bringup_and_idle() as dead_end_function |
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On Thu, 24 Jun 2021, Peter Zijlstra wrote:
> The asm_cpu_bringup_and_idle() function is required to push the return > value on the stack in order to make ORC happy, but the only reason > objtool doesn't complain is because of a happy accident. > > The thing is that asm_cpu_bringup_and_idle() doesn't return, so > validate_branch() never terminates and falls through to the next > function, which in the normal case is the hypercall_page. And that, as > it happens, is 4095 NOPs and a RET. > > Make asm_cpu_bringup_and_idle() terminate on it's own, by making the > function it calls as a dead-end. This way we no longer rely on what > code happens to come after. > > Fixes: c3881eb58d56 ("x86/xen: Make the secondary CPU idle tasks reliable") > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
M
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