Commit 76dc6d60 authored Oct 11, 2019 by Jiri Slaby Committed by Borislav Petkov Oct 18, 2019

x86/asm/entry: Annotate THUNKs



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 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

The annotation of .L_restore does not generate anything (at the moment).
Here, it just serves documentation purposes (as opening and closing
brackets of functions).

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-arch@vger.kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191011115108.12392-5-jslaby@suse.cz

parent 6ec2a968

arch/x86/entry/thunk_32.S

+2 −2

Original line number	Diff line number	Diff line
		@@ -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

arch/x86/entry/thunk_64.S

+4 −3

Original line number	Diff line number	Diff line
		@@ -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

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