Commit 29ea1b25 authored by Andy Lutomirski's avatar Andy Lutomirski Committed by Ingo Molnar
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x86/entry/64: Migrate 64-bit and compat syscalls to the new exit handlers and... 


x86/entry/64: Migrate 64-bit and compat syscalls to the new exit handlers and remove old assembly code

These need to be migrated together, as the compat case used to
jump into the middle of the 64-bit exit code.

Remove the old assembly code.

Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: paulmck@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/d4d1d70de08ac3640badf50048a9e8f18fe2497f.1435952415.git.luto@kernel.org


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent cb6f64ed

arch/x86/entry/entry_64.S

+8 −61
Original line number Diff line number Diff line
@@ -229,6 +229,11 @@ entry_SYSCALL_64_fastpath: 
	 */

	USERGS_SYSRET64



GLOBAL(int_ret_from_sys_call_irqs_off)

	TRACE_IRQS_ON

	ENABLE_INTERRUPTS(CLBR_NONE)

	jmp int_ret_from_sys_call



	/* Do syscall entry tracing */

tracesys:

	movq	%rsp, %rdi
@@ -272,69 +277,11 @@ tracesys_phase2: 
 * Has correct iret frame.

 */

GLOBAL(int_ret_from_sys_call)

	DISABLE_INTERRUPTS(CLBR_NONE)

int_ret_from_sys_call_irqs_off: /* jumps come here from the irqs-off SYSRET path */

	TRACE_IRQS_OFF

	movl	$_TIF_ALLWORK_MASK, %edi

	/* edi:	mask to check */

GLOBAL(int_with_check)

	LOCKDEP_SYS_EXIT_IRQ

	GET_THREAD_INFO(%rcx)

	movl	TI_flags(%rcx), %edx

	andl	%edi, %edx

	jnz	int_careful

	andl	$~TS_COMPAT, TI_status(%rcx)

	jmp	syscall_return



	/*

	 * Either reschedule or signal or syscall exit tracking needed.

	 * First do a reschedule test.

	 * edx:	work, edi: workmask

	 */

int_careful:

	bt	$TIF_NEED_RESCHED, %edx

	jnc	int_very_careful

	TRACE_IRQS_ON

	ENABLE_INTERRUPTS(CLBR_NONE)

	pushq	%rdi

	SCHEDULE_USER

	popq	%rdi

	DISABLE_INTERRUPTS(CLBR_NONE)

	TRACE_IRQS_OFF

	jmp	int_with_check



	/* handle signals and tracing -- both require a full pt_regs */

int_very_careful:

	TRACE_IRQS_ON

	ENABLE_INTERRUPTS(CLBR_NONE)

	SAVE_EXTRA_REGS

	/* Check for syscall exit trace */

	testl	$_TIF_WORK_SYSCALL_EXIT, %edx

	jz	int_signal

	pushq	%rdi

	leaq	8(%rsp), %rdi			/* &ptregs -> arg1 */

	call	syscall_trace_leave

	popq	%rdi

	andl	$~(_TIF_WORK_SYSCALL_EXIT|_TIF_SYSCALL_EMU), %edi

	jmp	int_restore_rest



int_signal:

	testl	$_TIF_DO_NOTIFY_MASK, %edx

	jz	1f

	movq	%rsp, %rdi			/* &ptregs -> arg1 */

	xorl	%esi, %esi			/* oldset -> arg2 */

	call	do_notify_resume

1:	movl	$_TIF_WORK_MASK, %edi

int_restore_rest:

	movq	%rsp, %rdi

	call	syscall_return_slowpath	/* returns with IRQs disabled */

	RESTORE_EXTRA_REGS

	DISABLE_INTERRUPTS(CLBR_NONE)

	TRACE_IRQS_OFF

	jmp	int_with_check



syscall_return:

	/* The IRETQ could re-enable interrupts: */

	DISABLE_INTERRUPTS(CLBR_ANY)

	TRACE_IRQS_IRETQ

	TRACE_IRQS_IRETQ		/* we're about to change IF */



	/*

	 * Try to use SYSRET instead of IRET if we're returning to

arch/x86/entry/entry_64_compat.S

+3 −3
Original line number Diff line number Diff line
@@ -210,10 +210,10 @@ sysexit_from_sys_call: 
	.endm



	.macro auditsys_exit exit

	testl	$(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT), ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)

	jnz	ia32_ret_from_sys_call

	TRACE_IRQS_ON

	ENABLE_INTERRUPTS(CLBR_NONE)

	testl	$(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT), ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)

	jnz	ia32_ret_from_sys_call

	movl	%eax, %esi		/* second arg, syscall return value */

	cmpl	$-MAX_ERRNO, %eax	/* is it an error ? */

	jbe	1f
@@ -232,7 +232,7 @@ sysexit_from_sys_call: 
	movq	%rax, R10(%rsp)

	movq	%rax, R9(%rsp)

	movq	%rax, R8(%rsp)

	jmp	int_with_check

	jmp	int_ret_from_sys_call_irqs_off

	.endm



sysenter_auditsys:

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