From: Peter Zijlstra <peterz@infradead.org> stable inclusion from stable-v5.10.133 commit 38a80a3ca2cb069dd5608703b015a206a672aae5 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5YVKO Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit d4b5a5c993009ffeb5febe3b701da3faab6adb96 upstream. Make sure we can see the text changes when booting with 'debug-alternative'. Example output: [ ] SMP alternatives: retpoline at: __traceiter_initcall_level+0x1f/0x30 (ffffffff8100066f) len: 5 to: __x86_indirect_thunk_rax+0x0/0x20 [ ] SMP alternatives: ffffffff82603e58: [2:5) optimized NOPs: ff d0 0f 1f 00 [ ] SMP alternatives: ffffffff8100066f: orig: e8 cc 30 00 01 [ ] SMP alternatives: ffffffff8100066f: repl: ff d0 0f 1f 00 Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Borislav Petkov <bp@suse.de> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Tested-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/r/20211026120310.422273830@infradead.org Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> Acked-by: Xie XiuQi <xiexiuqi@huawei.com> --- arch/x86/kernel/alternative.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index 487ade1768b1..fa79a46fa5d2 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -648,9 +648,15 @@ void __init_or_module noinline apply_retpolines(s32 *start, s32 *end) continue; } + DPRINTK("retpoline at: %pS (%px) len: %d to: %pS", + addr, addr, insn.length, + addr + insn.length + insn.immediate.value); + len = patch_retpoline(addr, &insn, bytes); if (len == insn.length) { optimize_nops(bytes, len); + DUMP_BYTES(((u8*)addr), len, "%px: orig: ", addr); + DUMP_BYTES(((u8*)bytes), len, "%px: repl: ", addr); text_poke_early(addr, bytes, len); } } -- 2.20.1