Commit c75388a8 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/ftrace: Prepare PPC64's ftrace_caller() for CONFIG_DYNAMIC_FTRACE_WITH_ARGS 



In order to implement CONFIG_DYNAMIC_FTRACE_WITH_ARGS, change ftrace_caller()
to handle LIVEPATCH the same way as frace_caller_regs().

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/850817333cc76593699032e8e9a70d8c36e1af1e.1640017960.git.christophe.leroy@csgroup.eu
parent d95bf254

arch/powerpc/kernel/trace/ftrace_64_mprofile.S

+19 −6
Original line number Diff line number Diff line
@@ -172,14 +172,19 @@ _GLOBAL(ftrace_caller) 
	addi	r3, r3, function_trace_op@toc@l

	ld	r5, 0(r3)



#ifdef CONFIG_LIVEPATCH_64

	SAVE_GPR(14, r1)

	mr	r14,r7		/* remember old NIP */

#endif

	/* Calculate ip from nip-4 into r3 for call below */

	subi    r3, r7, MCOUNT_INSN_SIZE



	/* Put the original return address in r4 as parent_ip */

	std	r0, _LINK(r1)

	mr	r4, r0



	/* Set pt_regs to NULL */

	li	r6, 0

	/* Load &pt_regs in r6 for call below */

	addi    r6, r1 ,STACK_FRAME_OVERHEAD



	/* ftrace_call(r3, r4, r5, r6) */

.globl ftrace_call
@@ -189,6 +194,10 @@ ftrace_call: 


	ld	r3, _NIP(r1)

	mtctr	r3

#ifdef CONFIG_LIVEPATCH_64

	cmpd	r14, r3		/* has NIP been altered? */

	REST_GPR(14, r1)

#endif



	/* Restore gprs */

	REST_GPRS(3, 10, r1)
@@ -196,13 +205,17 @@ ftrace_call: 
	/* Restore callee's TOC */

	ld	r2, 24(r1)



	/* Restore possibly modified LR */

	ld	r0, _LINK(r1)

	mtlr	r0



	/* Pop our stack frame */

	addi	r1, r1, SWITCH_FRAME_SIZE



	/* Reload original LR */

	ld	r0, LRSAVE(r1)

	mtlr	r0



#ifdef CONFIG_LIVEPATCH_64

        /* Based on the cmpd above, if the NIP was altered handle livepatch */

	bne-	livepatch_handler

#endif

	/* Handle function_graph or go back */

	b	ftrace_caller_common