git: 74d971fe1561 - main - x86: Add external retpoline thunk

The branch main has been updated by emaste:

URL: https://cgit.FreeBSD.org/src/commit/?id=74d971fe156113cc63add2e6701e369c93c4f52b

commit 74d971fe156113cc63add2e6701e369c93c4f52b
Author:     Ed Maste <emaste@FreeBSD.org>
AuthorDate: 2018-03-14 14:53:34 +0000
Commit:     Ed Maste <emaste@FreeBSD.org>
CommitDate: 2026-10-09 14:50:40 +0000

    x86: Add external retpoline thunk
    
    This allows use of -mindirect-branch=thunk-extern, and is only a few
    bytes of dead code if not used.
    
    Reviewed by:    kib
    Sponsored by:   The FreeBSD Foundation
    Differential Revision: https://reviews.freebsd.org/D60524
---
 sys/amd64/amd64/support.S | 10 ++++++++++
 sys/i386/i386/support.S   | 10 ++++++++++
 2 files changed, 20 insertions(+)

diff --git a/sys/amd64/amd64/support.S b/sys/amd64/amd64/support.S
index 1d7d05843ba8..b037e03f87f2 100644
--- a/sys/amd64/amd64/support.S
+++ b/sys/amd64/amd64/support.S
@@ -1996,4 +1996,14 @@ ENTRY(cpu_sync_core)
 	iretq
 END(cpu_sync_core)
 
+/* External Retpoline thunk */
+ENTRY(__x86_indirect_thunk_r11)
+	callq	2f
+1:	pause
+	lfence
+	jmp	1b
+2:	movq	%r11, (%rsp)
+	retq
+END(__x86_indirect_thunk_r11)
+
 	.section .note.GNU-stack,"",%progbits
diff --git a/sys/i386/i386/support.S b/sys/i386/i386/support.S
index e5e39c9ec5d4..cb6420750f77 100644
--- a/sys/i386/i386/support.S
+++ b/sys/i386/i386/support.S
@@ -587,4 +587,14 @@ ENTRY(cpu_sync_core)
 	iretl
 END(cpu_sync_core)
 
+/* External retpoline thunk */
+ENTRY(__x86_indirect_thunk_eax)
+	calll	2f
+1:	pause
+	lfence
+	jmp	1b
+2:	movl	%eax, (%esp)
+	retl
+END(__x86_indirect_thunk_eax)
+
 	.section .note.GNU-stack,"",%progbits