lkml.org 
[lkml]   [2021]   [Jun]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH v2 01/24] x86/xen: Mark cpu_bringup_and_idle() as dead_end_function
    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

    \
     
     \ /
      Last update: 2021-06-30 13:48    [W:3.862 / U:0.004 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site