Subject: [PATCH 07/22] arm64: entry: Move trampoline macros out of ifdef'd section
From: James Morse <james.morse@arm.com>
Date: 18/11/2021, 15:02

Git-commit: 13d7a08352a83ef2252aeb464a5e08dfc06b5dfd
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
Patch-mainline: Queued in a subsystem tree
References: bsc#1191580 CVE-2022-0001 CVE-2022-0002

The macros for building the kpti trampoline are all behind
CONFIG_UNMAP_KERNEL_AT_EL0, and in a region that outputs to the
.entry.tramp.text section.

Move the macros out so they can be used to generate other kinds of
trampoline. Only the symbols need to be guarded by
CONFIG_UNMAP_KERNEL_AT_EL0 and appear in the .entry.tramp.text section.

Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Matthias Brugger <mbrugger@suse.com>
---
 arch/arm64/kernel/entry.S |   11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -1025,12 +1025,6 @@ ENDPROC(el0_svc)
 
 	.popsection				// .entry.text
 
-#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
-/*
- * Exception vectors trampoline.
- */
-	.pushsection ".entry.tramp.text", "ax"
-
 	.macro tramp_map_kernel, tmp
 	mrs	\tmp, ttbr1_el1
 	add	\tmp, \tmp, #(PAGE_SIZE + RESERVED_TTBR0_SIZE)
@@ -1124,6 +1118,11 @@ alternative_else_nop_endif
 	.endr
 	.endm
 
+#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
+/*
+ * Exception vectors trampoline.
+ */
+	.pushsection ".entry.tramp.text", "ax"
 	.align	11
 ENTRY(tramp_vectors)
 	generate_tramp_vector