x86/entry/64: Provide sane error entry/exit (424c7d0a) · Commits · 戴 / test

arch/x86/entry/entry_64.S

+19 −3

Original line number	Diff line number	Diff line
		@@ -499,8 +499,9 @@ SYM_CODE_END(spurious_entries_start)
		* @vector: Vector number
		* @cfunc: C function to be called
		* @has_error_code: Hardware pushed error code on stack
		* @sane: Sane variant which handles irq tracing, context tracking in C
		*/
		.macro idtentry_body vector cfunc has_error_code:req
		.macro idtentry_body vector cfunc has_error_code:req sane=0

		call error_entry
		UNWIND_HINT_REGS
		@@ -514,6 +515,7 @@ SYM_CODE_END(spurious_entries_start)
		GET_CR2_INTO(%r12);
		.endif

		.if \sane == 0
		TRACE_IRQS_OFF

		#ifdef CONFIG_CONTEXT_TRACKING
		@@ -522,6 +524,7 @@ SYM_CODE_END(spurious_entries_start)
		CALL_enter_from_user_mode
		.Lfrom_kernel_no_ctxt_tracking_\@:
		#endif
		.endif

		movq %rsp, %rdi /* pt_regs pointer into 1st argument*/

		@@ -538,7 +541,11 @@ SYM_CODE_END(spurious_entries_start)

		call \cfunc

		.if \sane == 0
		jmp error_exit
		.else
		jmp error_return
		.endif
		.endm

		/**
		@@ -547,11 +554,12 @@ SYM_CODE_END(spurious_entries_start)
		* @asmsym: ASM symbol for the entry point
		* @cfunc: C function to be called
		* @has_error_code: Hardware pushed error code on stack
		* @sane: Sane variant which handles irq tracing, context tracking in C
		*
		* The macro emits code to set up the kernel context for straight forward
		* and simple IDT entries. No IST stack, no paranoid entry checks.
		*/
		.macro idtentry vector asmsym cfunc has_error_code:req
		.macro idtentry vector asmsym cfunc has_error_code:req sane=0
		SYM_CODE_START(\asmsym)
		UNWIND_HINT_IRET_REGS offset=\has_error_code*8
		ASM_CLAC
		@@ -574,7 +582,7 @@ SYM_CODE_START(\asmsym)
		.Lfrom_usermode_no_gap_\@:
		.endif

		idtentry_body \vector \cfunc \has_error_code
		idtentry_body \vector \cfunc \has_error_code \sane

		_ASM_NOKPROBE(\asmsym)
		SYM_CODE_END(\asmsym)
		@@ -1403,6 +1411,14 @@ SYM_CODE_START_LOCAL(error_exit)
		jmp .Lretint_user
		SYM_CODE_END(error_exit)

		SYM_CODE_START_LOCAL(error_return)
		UNWIND_HINT_REGS
		DEBUG_ENTRY_ASSERT_IRQS_OFF
		testb $3, CS(%rsp)
		jz restore_regs_and_return_to_kernel
		jmp swapgs_restore_regs_and_return_to_usermode
		SYM_CODE_END(error_return)

		/*
		* Runs on exception stack. Xen PV does not go through this path at all,
		* so we can use real assembly here.

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