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authorPeter Zijlstra <peterz@infradead.org>2021-06-24 12:41:00 +0300
committerPeter Zijlstra <peterz@infradead.org>2021-09-15 16:51:44 +0300
commit9af9dcf11bda3e2c0e24c1acaacb8685ad974e93 (patch)
tree179b8ed6ba33d8297ddb28ce3c6a0719c983f6a7 /tools/objtool
parent6880fa6c56601bb8ed59df6c30fd390cc5f6dd8f (diff)
downloadlinux-9af9dcf11bda3e2c0e24c1acaacb8685ad974e93.tar.xz
x86/xen: Mark cpu_bringup_and_idle() as dead_end_function
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: Juergen Gross <jgross@suse.com> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Link: https://lore.kernel.org/r/20210624095147.693801717@infradead.org
Diffstat (limited to 'tools/objtool')
-rw-r--r--tools/objtool/check.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index e5947fbb9e7a..0e3981d91afc 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -173,6 +173,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
"rewind_stack_do_exit",
"kunit_try_catch_throw",
"xen_start_kernel",
+ "cpu_bringup_and_idle",
};
if (!func)