[PATCH 02/29] x86/module: Fix the paravirt vs alternative order

From: Peter Zijlstra
Date: Fri Feb 18 2022 - 12:16:03 EST


Ever since commit 4e6292114c741 ("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: 4e6292114c741 ("x86/paravirt: Add new features for paravirt patching")
Cc: Juergen Gross <jgross@xxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
arch/x86/kernel/module.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)

--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -272,6 +272,10 @@ int module_finalize(const Elf_Ehdr *hdr,
retpolines = s;
}

+ 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);
@@ -289,11 +293,6 @@ 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);