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    Subject[PATCH 5.10 023/130] objtool: Correctly handle retpoline thunk calls
    Date
    From: Peter Zijlstra <peterz@infradead.org>

    commit bcb1b6ff39da7e8a6a986eb08126fba2b5e13c32 upstream.

    Just like JMP handling, convert a direct CALL to a retpoline thunk
    into a retpoline safe indirect CALL.

    Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
    Signed-off-by: Borislav Petkov <bp@suse.de>
    Signed-off-by: Ingo Molnar <mingo@kernel.org>
    Reviewed-by: Miroslav Benes <mbenes@suse.cz>
    Link: https://lkml.kernel.org/r/20210326151259.567568238@infradead.org
    Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    ---
    tools/objtool/check.c | 12 ++++++++++++
    1 file changed, 12 insertions(+)

    --- a/tools/objtool/check.c
    +++ b/tools/objtool/check.c
    @@ -953,6 +953,18 @@ static int add_call_destinations(struct
    dest_off);
    return -1;
    }
    +
    + } else if (!strncmp(reloc->sym->name, "__x86_indirect_thunk_", 21)) {
    + /*
    + * Retpoline calls are really dynamic calls in
    + * disguise, so convert them accordingly.
    + */
    + insn->type = INSN_CALL_DYNAMIC;
    + insn->retpoline_safe = true;
    +
    + remove_insn_ops(insn);
    + continue;
    +
    } else
    insn->call_dest = reloc->sym;


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