arm64: ftrace: remove return_regs macros (49e258e0) · Commits · 戴 / test

The save_return_regs and restore_return_regs macros are only used by return_to_handler, and having them defined out-of-line only serves to obscure the logic. Before we complicate, let's clean this up and fold the logic directly into return_to_handler, saving a few lines of macro boilerplate in the process. At the same time, a missing trailing space is added to the comments, fixing a code style violation. There should be no functional change as a result of this patch. Signed-off-by:

Mark Rutland <mark.rutland@arm.com> Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Torsten Duwe <duwe@suse.de> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by:

Will Deacon <will.deacon@arm.com>

arch/arm64/kernel/entry-ftrace.S

+15 −20

Original line number	Diff line number	Diff line
		@@ -166,24 +166,6 @@ ENTRY(ftrace_stub)
		ENDPROC(ftrace_stub)

		#ifdef CONFIG_FUNCTION_GRAPH_TRACER
		/* save return value regs*/
		.macro save_return_regs
		sub sp, sp, #64
		stp x0, x1, [sp]
		stp x2, x3, [sp, #16]
		stp x4, x5, [sp, #32]
		stp x6, x7, [sp, #48]
		.endm

		/* restore return value regs*/
		.macro restore_return_regs
		ldp x0, x1, [sp]
		ldp x2, x3, [sp, #16]
		ldp x4, x5, [sp, #32]
		ldp x6, x7, [sp, #48]
		add sp, sp, #64
		.endm

		/*
		* void ftrace_graph_caller(void)
		*
		@@ -209,11 +191,24 @@ ENDPROC(ftrace_graph_caller)
		* @fp is checked against the value passed by ftrace_graph_caller().
		*/
		ENTRY(return_to_handler)
		save_return_regs
		/* save return value regs */
		sub sp, sp, #64
		stp x0, x1, [sp]
		stp x2, x3, [sp, #16]
		stp x4, x5, [sp, #32]
		stp x6, x7, [sp, #48]

		mov x0, x29 // parent's fp
		bl ftrace_return_to_handler// addr = ftrace_return_to_hander(fp);
		mov x30, x0 // restore the original return address
		restore_return_regs

		/* restore return value regs */
		ldp x0, x1, [sp]
		ldp x2, x3, [sp, #16]
		ldp x4, x5, [sp, #32]
		ldp x6, x7, [sp, #48]
		add sp, sp, #64

		ret
		END(return_to_handler)
		#endif /* CONFIG_FUNCTION_GRAPH_TRACER */

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