smoverlay/app-emulation/vmware-modules/files/329-02-vmmon-fix-indirect-c...

50 lines
1.8 KiB
Diff
Raw Normal View History

From 6392262b68387299ee81d5d659cb5423a2ae1c9c Mon Sep 17 00:00:00 2001
From: Michal Kubecek <mkubecek@suse.cz>
Date: Mon, 26 Mar 2018 13:33:32 +0200
Subject: [PATCH 09/10] vmmon: fix indirect call with retpoline build
Build against kernel with retpoline support issues warning
objtool: Task_Switch()+0x425: indirect call found in RETPOLINE build
This is because an indirect call in TaskSwitchToMonitor() is encoded using
inline assembler so that it bypasses retpoline generation. For this
purpose, macro CALL_NOSPEC exists since v4.15-rc8 (and has been backported
into some distribution kernels with the rest of retpoline support). Use the
macro if available and fallback to the original code if not.
---
vmmon-only/common/task.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/vmmon-only/common/task.c b/vmmon-only/common/task.c
index 98cc74a..400ebfe 100644
--- a/vmmon-only/common/task.c
+++ b/vmmon-only/common/task.c
@@ -2203,12 +2203,23 @@ TaskSwitchToMonitor(VMCrossPage *crosspage)
{
uint64 raxGetsWiped, rcxGetsWiped;
+#ifdef CALL_NOSPEC
+ __asm__ __volatile__(CALL_NOSPEC
+ : "=a" (raxGetsWiped),
+ "=c" (rcxGetsWiped)
+ : "0" (codePtr),
+ "1" (crosspage),
+ THUNK_TARGET(codePtr)
+ : "rdx", "r8", "r9", "r10", "r11", "cc", "memory");
+#else
__asm__ __volatile__("call *%%rax"
: "=a" (raxGetsWiped),
"=c" (rcxGetsWiped)
: "0" (codePtr),
"1" (crosspage)
: "rdx", "r8", "r9", "r10", "r11", "cc", "memory");
+#endif
+
}
#elif defined(_MSC_VER)
/*
--
2.17.0