[PATCH v4 04/27] x86: entry, annotate THUNKs

Jiri Slaby
2017-10-02T09:12:52Z

Place SYM_CODE_START_NOALIGN and SYM_CODE_END around the THUNK macro
body, given it generates:
1) non-C-like functions, and
2) was not marked as aligned.

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 NOTYPE GLOBAL DEFAULT 1 trace_hardirqs_on_thunk
001c 28 NOTYPE GLOBAL DEFAULT 1 trace_hardirqs_off_thunk
0038 24 NOTYPE GLOBAL DEFAULT 1 lockdep_sys_exit_thunk
0050 24 NOTYPE GLOBAL DEFAULT 1 ___preempt_schedule
0068 24 NOTYPE GLOBAL DEFAULT 1 ___preempt_schedule_notrace

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <x86@kernel.org>
---
arch/x86/entry/thunk_32.S | 4 ++--
arch/x86/entry/thunk_64.S | 8 ++++----
2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/x86/entry/thunk_32.S b/arch/x86/entry/thunk_32.S
index fee6bc79b987..422354b204f4 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 be36bf4e0957..ea5e2b0e6611 100644
--- a/arch/x86/entry/thunk_64.S
+++ b/arch/x86/entry/thunk_64.S
@@ -12,9 +12,7 @@

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

@@ -36,6 +34,7 @@
call \func
jmp .L_restore
_ASM_NOKPROBE(\name)
+SYM_CODE_END(\name)
.endm

#ifdef CONFIG_TRACE_IRQFLAGS
@@ -57,7 +56,7 @@
#if defined(CONFIG_TRACE_IRQFLAGS) \
|| defined(CONFIG_DEBUG_LOCK_ALLOC) \
|| defined(CONFIG_PREEMPT)
-.L_restore:
+SYM_CODE_START_LOCAL_NOALIGN(.L_restore)
popq %r11
popq %r10
popq %r9
@@ -70,4 +69,5 @@
popq %rbp
ret
_ASM_NOKPROBE(.L_restore)
+SYM_CODE_END(.L_restore)
#endif
--
2.14.2