[PATCH v8 04/28] x86/asm/entry: annotate THUNKs

From: Jiri Slaby
Date: Thu Aug 08 2019 - 06:40:38 EST


Place SYM_*_START_NOALIGN and SYM_*_END around the THUNK macro body.
Preserve @function by FUNC (64bit) and CODE (32bit). Given it was not
marked as aligned, use NOALIGN.

The common tail .L_restore is put inside SYM_CODE_START_LOCAL_NOALIGN
and SYM_CODE_END too.

The result:
Value Size Type Bind Vis Ndx Name
0000 28 FUNC GLOBAL DEFAULT 1 trace_hardirqs_on_thunk
001c 28 FUNC GLOBAL DEFAULT 1 trace_hardirqs_off_thunk
0038 24 FUNC GLOBAL DEFAULT 1 lockdep_sys_exit_thunk
0050 24 FUNC GLOBAL DEFAULT 1 ___preempt_schedule
0068 24 FUNC GLOBAL DEFAULT 1 ___preempt_schedule_notra

Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: <x86@xxxxxxxxxx>
---
arch/x86/entry/thunk_32.S | 4 ++--
arch/x86/entry/thunk_64.S | 7 ++++---
2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/arch/x86/entry/thunk_32.S b/arch/x86/entry/thunk_32.S
index 2713490611a3..e010d4ae11f1 100644
--- a/arch/x86/entry/thunk_32.S
+++ b/arch/x86/entry/thunk_32.S
@@ -10,8 +10,7 @@

/* put return address in eax (arg1) */
.macro THUNK name, func, put_ret_addr_in_eax=0
- .globl \name
-\name:
+SYM_CODE_START_NOALIGN(\name)
pushl %eax
pushl %ecx
pushl %edx
@@ -27,6 +26,7 @@
popl %eax
ret
_ASM_NOKPROBE(\name)
+SYM_CODE_END(\name)
.endm

#ifdef CONFIG_TRACE_IRQFLAGS
diff --git a/arch/x86/entry/thunk_64.S b/arch/x86/entry/thunk_64.S
index ea5c4167086c..c5c3b6e86e62 100644
--- a/arch/x86/entry/thunk_64.S
+++ b/arch/x86/entry/thunk_64.S
@@ -12,7 +12,7 @@

/* rdi: arg1 ... normal C conventions. rax is saved/restored. */
.macro THUNK name, func, put_ret_addr_in_rdi=0
- ENTRY(\name)
+SYM_FUNC_START_NOALIGN(\name)
pushq %rbp
movq %rsp, %rbp

@@ -33,7 +33,7 @@

call \func
jmp .L_restore
- ENDPROC(\name)
+SYM_FUNC_END(\name)
_ASM_NOKPROBE(\name)
.endm

@@ -56,7 +56,7 @@
#if defined(CONFIG_TRACE_IRQFLAGS) \
|| defined(CONFIG_DEBUG_LOCK_ALLOC) \
|| defined(CONFIG_PREEMPTION)
-.L_restore:
+SYM_CODE_START_LOCAL_NOALIGN(.L_restore)
popq %r11
popq %r10
popq %r9
@@ -69,4 +69,5 @@
popq %rbp
ret
_ASM_NOKPROBE(.L_restore)
+SYM_CODE_END(.L_restore)
#endif
--
2.22.0