From: Peter Zijlstra <peterz@infradead.org>
Date: Thu, 3 Mar 2022 11:23:23 +0000 (+0100)
Subject: x86/module: Fix the paravirt vs alternative order
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=df3817ab226f8d7cb9164d88ff3958aa2b9ad8cc;p=linux.git

x86/module: Fix the paravirt vs alternative order

commit 5adf349439d29f92467e864f728dfc23180f3ef9 upstream.

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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
index 867a341a0c7e8..32e546e416296 100644
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -270,6 +270,14 @@ int module_finalize(const Elf_Ehdr *hdr,
 			orc_ip = 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 (alt) {
 		/* patch .altinstructions */
 		void *aseg = (void *)alt->sh_addr;
@@ -283,11 +291,6 @@ 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);