x86/module: Fix the paravirt vs alternative order
authorPeter Zijlstra <peterz@infradead.org>
Thu, 3 Mar 2022 11:23:23 +0000 (12:23 +0100)
committerBorislav Petkov <bp@suse.de>
Tue, 8 Mar 2022 13:15:25 +0000 (14:15 +0100)
Ever since commit

  4e6292114c74 ("x86/paravirt: Add new features for paravirt patching")

there is an ordering dependency between patching paravirt ops and
patching alternatives, the module loader still violates this.

Fixes: 4e6292114c74 ("x86/paravirt: Add new features for paravirt patching")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20220303112825.068773913@infradead.org
arch/x86/kernel/module.c

index 95fa745..96d7c27 100644 (file)
@@ -273,6 +273,14 @@ int module_finalize(const Elf_Ehdr *hdr,
                        retpolines = s;
        }
 
+       /*
+        * See alternative_instructions() for the ordering rules between the
+        * various patching types.
+        */
+       if (para) {
+               void *pseg = (void *)para->sh_addr;
+               apply_paravirt(pseg, pseg + para->sh_size);
+       }
        if (retpolines) {
                void *rseg = (void *)retpolines->sh_addr;
                apply_retpolines(rseg, rseg + retpolines->sh_size);
@@ -290,11 +298,6 @@ int module_finalize(const Elf_Ehdr *hdr,
                                            tseg, tseg + text->sh_size);
        }
 
-       if (para) {
-               void *pseg = (void *)para->sh_addr;
-               apply_paravirt(pseg, pseg + para->sh_size);
-       }
-
        /* make jump label nops */
        jump_label_apply_nops(me);