[PATCH v3 11/19] x86: Move return_thunk to __pitext section

Ard Biesheuvel
2024-01-29T18:05:56Z

From: Ard Biesheuvel <ardb@kernel.org>

The x86 return thunk will function correctly even when it is called via
a different virtual mapping than the one it was linked at, so it can
safely be moved to .pi.text. This allows other code in that section to
call it.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
arch/x86/kernel/vmlinux.lds.S | 2 +-
arch/x86/lib/retpoline.S | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index a349dbfc6d5a..77262e804250 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -134,7 +134,7 @@ SECTIONS
SOFTIRQENTRY_TEXT
#ifdef CONFIG_RETPOLINE
*(.text..__x86.indirect_thunk)
- *(.text..__x86.return_thunk)
+ *(.pi.text..__x86.return_thunk)
#endif
STATIC_CALL_TEXT

diff --git a/arch/x86/lib/retpoline.S b/arch/x86/lib/retpoline.S
index 7b2589877d06..003b35445bbb 100644
--- a/arch/x86/lib/retpoline.S
+++ b/arch/x86/lib/retpoline.S
@@ -136,7 +136,7 @@ SYM_CODE_END(__x86_indirect_jump_thunk_array)
* relocations for same-section JMPs and that breaks the returns
* detection logic in apply_returns() and in objtool.
*/
- .section .text..__x86.return_thunk
+ .section .pi.text..__x86.return_thunk, "ax"

#ifdef CONFIG_CPU_SRSO

--
2.43.0.429.g432eaa2c6b-goog