Commit 096ff2dd authored by Naveen N. Rao's avatar Naveen N. Rao Committed by Michael Ellerman
Browse files

powerpc/ftrace/64: Split further based on -mprofile-kernel 



Split ftrace_64.S further retaining the core ftrace 64-bit aspects
in ftrace_64.S and moving ftrace_caller() and ftrace_graph_caller() into
separate files based on -mprofile-kernel. The livepatch routines are all
now contained within the mprofile file.

Signed-off-by: default avatarNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 7853f9c0

arch/powerpc/kernel/trace/Makefile

+5 −0
Original line number Diff line number Diff line
@@ -11,6 +11,11 @@ endif 


obj32-$(CONFIG_FUNCTION_TRACER)		+= ftrace_32.o

obj64-$(CONFIG_FUNCTION_TRACER)		+= ftrace_64.o

ifdef CONFIG_MPROFILE_KERNEL

obj64-$(CONFIG_FUNCTION_TRACER)		+= ftrace_64_mprofile.o

else

obj64-$(CONFIG_FUNCTION_TRACER)		+= ftrace_64_pg.o

endif

obj-$(CONFIG_DYNAMIC_FTRACE)		+= ftrace.o

obj-$(CONFIG_FUNCTION_GRAPH_TRACER)	+= ftrace.o

obj-$(CONFIG_FTRACE_SYSCALLS)		+= ftrace.o

arch/powerpc/kernel/trace/ftrace_64.S

+1 −305
Original line number Diff line number Diff line
@@ -23,233 +23,7 @@ EXPORT_SYMBOL(_mcount) 
	mtlr	r0

	bctr



#ifndef CC_USING_MPROFILE_KERNEL

_GLOBAL_TOC(ftrace_caller)

	/* Taken from output of objdump from lib64/glibc */

	mflr	r3

	ld	r11, 0(r1)

	stdu	r1, -112(r1)

	std	r3, 128(r1)

	ld	r4, 16(r11)

	subi	r3, r3, MCOUNT_INSN_SIZE

.globl ftrace_call

ftrace_call:

	bl	ftrace_stub

	nop

#ifdef CONFIG_FUNCTION_GRAPH_TRACER

.globl ftrace_graph_call

ftrace_graph_call:

	b	ftrace_graph_stub

_GLOBAL(ftrace_graph_stub)

#endif

	ld	r0, 128(r1)

	mtlr	r0

	addi	r1, r1, 112



#else /* CC_USING_MPROFILE_KERNEL */

/*

 *

 * ftrace_caller() is the function that replaces _mcount() when ftrace is

 * active.

 *

 * We arrive here after a function A calls function B, and we are the trace

 * function for B. When we enter r1 points to A's stack frame, B has not yet

 * had a chance to allocate one yet.

 *

 * Additionally r2 may point either to the TOC for A, or B, depending on

 * whether B did a TOC setup sequence before calling us.

 *

 * On entry the LR points back to the _mcount() call site, and r0 holds the

 * saved LR as it was on entry to B, ie. the original return address at the

 * call site in A.

 *

 * Our job is to save the register state into a struct pt_regs (on the stack)

 * and then arrange for the ftrace function to be called.

 */

_GLOBAL(ftrace_caller)

	/* Save the original return address in A's stack frame */

	std	r0,LRSAVE(r1)



	/* Create our stack frame + pt_regs */

	stdu	r1,-SWITCH_FRAME_SIZE(r1)



	/* Save all gprs to pt_regs */

	SAVE_8GPRS(0,r1)

	SAVE_8GPRS(8,r1)

	SAVE_8GPRS(16,r1)

	SAVE_8GPRS(24,r1)



	/* Load special regs for save below */

	mfmsr   r8

	mfctr   r9

	mfxer   r10

	mfcr	r11



	/* Get the _mcount() call site out of LR */

	mflr	r7

	/* Save it as pt_regs->nip */

	std     r7, _NIP(r1)

	/* Save the read LR in pt_regs->link */

	std     r0, _LINK(r1)



	/* Save callee's TOC in the ABI compliant location */

	std	r2, 24(r1)

	ld	r2,PACATOC(r13)	/* get kernel TOC in r2 */



	addis	r3,r2,function_trace_op@toc@ha

	addi	r3,r3,function_trace_op@toc@l

	ld	r5,0(r3)



#ifdef CONFIG_LIVEPATCH

	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 */

	mr	r4, r0



	/* Save special regs */

	std     r8, _MSR(r1)

	std     r9, _CTR(r1)

	std     r10, _XER(r1)

	std     r11, _CCR(r1)



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

	addi    r6, r1 ,STACK_FRAME_OVERHEAD



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

.globl ftrace_call

ftrace_call:

	bl	ftrace_stub

	nop



	/* Load ctr with the possibly modified NIP */

	ld	r3, _NIP(r1)

	mtctr	r3

#ifdef CONFIG_LIVEPATCH

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

#endif



	/* Restore gprs */

	REST_8GPRS(0,r1)

	REST_8GPRS(8,r1)

	REST_8GPRS(16,r1)

	REST_8GPRS(24,r1)



	/* Restore possibly modified LR */

	ld	r0, _LINK(r1)

	mtlr	r0



	/* Restore callee's TOC */

	ld	r2, 24(r1)



	/* Pop our stack frame */

	addi r1, r1, SWITCH_FRAME_SIZE



#ifdef CONFIG_LIVEPATCH

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

	bne-	livepatch_handler

#endif



#ifdef CONFIG_FUNCTION_GRAPH_TRACER

.globl ftrace_graph_call

ftrace_graph_call:

	b	ftrace_graph_stub

_GLOBAL(ftrace_graph_stub)

#endif



	bctr			/* jump after _mcount site */

#endif /* CC_USING_MPROFILE_KERNEL */



_GLOBAL(ftrace_stub)

	blr



#ifdef CONFIG_LIVEPATCH

	/*

	 * This function runs in the mcount context, between two functions. As

	 * such it can only clobber registers which are volatile and used in

	 * function linkage.

	 *

	 * We get here when a function A, calls another function B, but B has

	 * been live patched with a new function C.

	 *

	 * On entry:

	 *  - we have no stack frame and can not allocate one

	 *  - LR points back to the original caller (in A)

	 *  - CTR holds the new NIP in C

	 *  - r0 & r12 are free

	 *

	 * r0 can't be used as the base register for a DS-form load or store, so

	 * we temporarily shuffle r1 (stack pointer) into r0 and then put it back.

	 */

livepatch_handler:

	CURRENT_THREAD_INFO(r12, r1)



	/* Save stack pointer into r0 */

	mr	r0, r1



	/* Allocate 3 x 8 bytes */

	ld	r1, TI_livepatch_sp(r12)

	addi	r1, r1, 24

	std	r1, TI_livepatch_sp(r12)



	/* Save toc & real LR on livepatch stack */

	std	r2,  -24(r1)

	mflr	r12

	std	r12, -16(r1)



	/* Store stack end marker */

	lis     r12, STACK_END_MAGIC@h

	ori     r12, r12, STACK_END_MAGIC@l

	std	r12, -8(r1)



	/* Restore real stack pointer */

	mr	r1, r0



	/* Put ctr in r12 for global entry and branch there */

	mfctr	r12

	bctrl



	/*

	 * Now we are returning from the patched function to the original

	 * caller A. We are free to use r0 and r12, and we can use r2 until we

	 * restore it.

	 */



	CURRENT_THREAD_INFO(r12, r1)



	/* Save stack pointer into r0 */

	mr	r0, r1



	ld	r1, TI_livepatch_sp(r12)



	/* Check stack marker hasn't been trashed */

	lis     r2,  STACK_END_MAGIC@h

	ori     r2,  r2, STACK_END_MAGIC@l

	ld	r12, -8(r1)

1:	tdne	r12, r2

	EMIT_BUG_ENTRY 1b, __FILE__, __LINE__ - 1, 0



	/* Restore LR & toc from livepatch stack */

	ld	r12, -16(r1)

	mtlr	r12

	ld	r2,  -24(r1)



	/* Pop livepatch stack frame */

	CURRENT_THREAD_INFO(r12, r0)

	subi	r1, r1, 24

	std	r1, TI_livepatch_sp(r12)



	/* Restore real stack pointer */

	mr	r1, r0



	/* Return to original caller of live patched function */

	blr

#endif





#else

#else /* CONFIG_DYNAMIC_FTRACE */

_GLOBAL_TOC(_mcount)

EXPORT_SYMBOL(_mcount)

	/* Taken from output of objdump from lib64/glibc */
@@ -267,7 +41,6 @@ EXPORT_SYMBOL(_mcount) 
	bctrl

	nop





#ifdef CONFIG_FUNCTION_GRAPH_TRACER

	b	ftrace_graph_caller

#endif
@@ -276,86 +49,9 @@ EXPORT_SYMBOL(_mcount) 
	addi	r1, r1, 112

_GLOBAL(ftrace_stub)

	blr



#endif /* CONFIG_DYNAMIC_FTRACE */



#ifdef CONFIG_FUNCTION_GRAPH_TRACER

#ifndef CC_USING_MPROFILE_KERNEL

_GLOBAL(ftrace_graph_caller)

	/* load r4 with local address */

	ld	r4, 128(r1)

	subi	r4, r4, MCOUNT_INSN_SIZE



	/* Grab the LR out of the caller stack frame */

	ld	r11, 112(r1)

	ld	r3, 16(r11)



	bl	prepare_ftrace_return

	nop



	/*

	 * prepare_ftrace_return gives us the address we divert to.

	 * Change the LR in the callers stack frame to this.

	 */

	ld	r11, 112(r1)

	std	r3, 16(r11)



	ld	r0, 128(r1)

	mtlr	r0

	addi	r1, r1, 112

	blr



#else /* CC_USING_MPROFILE_KERNEL */

_GLOBAL(ftrace_graph_caller)

	stdu	r1, -112(r1)

	/* with -mprofile-kernel, parameter regs are still alive at _mcount */

	std	r10, 104(r1)

	std	r9, 96(r1)

	std	r8, 88(r1)

	std	r7, 80(r1)

	std	r6, 72(r1)

	std	r5, 64(r1)

	std	r4, 56(r1)

	std	r3, 48(r1)



	/* Save callee's TOC in the ABI compliant location */

	std	r2, 24(r1)

	ld	r2, PACATOC(r13)	/* get kernel TOC in r2 */



	mfctr	r4		/* ftrace_caller has moved local addr here */

	std	r4, 40(r1)

	mflr	r3		/* ftrace_caller has restored LR from stack */

	subi	r4, r4, MCOUNT_INSN_SIZE



	bl	prepare_ftrace_return

	nop



	/*

	 * prepare_ftrace_return gives us the address we divert to.

	 * Change the LR to this.

	 */

	mtlr	r3



	ld	r0, 40(r1)

	mtctr	r0

	ld	r10, 104(r1)

	ld	r9, 96(r1)

	ld	r8, 88(r1)

	ld	r7, 80(r1)

	ld	r6, 72(r1)

	ld	r5, 64(r1)

	ld	r4, 56(r1)

	ld	r3, 48(r1)



	/* Restore callee's TOC */

	ld	r2, 24(r1)



	addi	r1, r1, 112

	mflr	r0

	std	r0, LRSAVE(r1)

	bctr

#endif /* CC_USING_MPROFILE_KERNEL */



_GLOBAL(return_to_handler)

	/* need to save return values */

	std	r4,  -32(r1)

arch/powerpc/kernel/trace/ftrace_64_mprofile.S

0 → 100644
+272 −0
Original line number Diff line number Diff line 
/*

 * Split from ftrace_64.S

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version

 * 2 of the License, or (at your option) any later version.

 */



#include <linux/magic.h>

#include <asm/ppc_asm.h>

#include <asm/asm-offsets.h>

#include <asm/ftrace.h>

#include <asm/ppc-opcode.h>

#include <asm/export.h>

#include <asm/thread_info.h>

#include <asm/bug.h>

#include <asm/ptrace.h>



#ifdef CONFIG_DYNAMIC_FTRACE

/*

 *

 * ftrace_caller() is the function that replaces _mcount() when ftrace is

 * active.

 *

 * We arrive here after a function A calls function B, and we are the trace

 * function for B. When we enter r1 points to A's stack frame, B has not yet

 * had a chance to allocate one yet.

 *

 * Additionally r2 may point either to the TOC for A, or B, depending on

 * whether B did a TOC setup sequence before calling us.

 *

 * On entry the LR points back to the _mcount() call site, and r0 holds the

 * saved LR as it was on entry to B, ie. the original return address at the

 * call site in A.

 *

 * Our job is to save the register state into a struct pt_regs (on the stack)

 * and then arrange for the ftrace function to be called.

 */

_GLOBAL(ftrace_caller)

	/* Save the original return address in A's stack frame */

	std	r0,LRSAVE(r1)



	/* Create our stack frame + pt_regs */

	stdu	r1,-SWITCH_FRAME_SIZE(r1)



	/* Save all gprs to pt_regs */

	SAVE_8GPRS(0,r1)

	SAVE_8GPRS(8,r1)

	SAVE_8GPRS(16,r1)

	SAVE_8GPRS(24,r1)



	/* Load special regs for save below */

	mfmsr   r8

	mfctr   r9

	mfxer   r10

	mfcr	r11



	/* Get the _mcount() call site out of LR */

	mflr	r7

	/* Save it as pt_regs->nip */

	std     r7, _NIP(r1)

	/* Save the read LR in pt_regs->link */

	std     r0, _LINK(r1)



	/* Save callee's TOC in the ABI compliant location */

	std	r2, 24(r1)

	ld	r2,PACATOC(r13)	/* get kernel TOC in r2 */



	addis	r3,r2,function_trace_op@toc@ha

	addi	r3,r3,function_trace_op@toc@l

	ld	r5,0(r3)



#ifdef CONFIG_LIVEPATCH

	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 */

	mr	r4, r0



	/* Save special regs */

	std     r8, _MSR(r1)

	std     r9, _CTR(r1)

	std     r10, _XER(r1)

	std     r11, _CCR(r1)



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

	addi    r6, r1 ,STACK_FRAME_OVERHEAD



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

.globl ftrace_call

ftrace_call:

	bl	ftrace_stub

	nop



	/* Load ctr with the possibly modified NIP */

	ld	r3, _NIP(r1)

	mtctr	r3

#ifdef CONFIG_LIVEPATCH

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

#endif



	/* Restore gprs */

	REST_8GPRS(0,r1)

	REST_8GPRS(8,r1)

	REST_8GPRS(16,r1)

	REST_8GPRS(24,r1)



	/* Restore possibly modified LR */

	ld	r0, _LINK(r1)

	mtlr	r0



	/* Restore callee's TOC */

	ld	r2, 24(r1)



	/* Pop our stack frame */

	addi r1, r1, SWITCH_FRAME_SIZE



#ifdef CONFIG_LIVEPATCH

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

	bne-	livepatch_handler

#endif



#ifdef CONFIG_FUNCTION_GRAPH_TRACER

.globl ftrace_graph_call

ftrace_graph_call:

	b	ftrace_graph_stub

_GLOBAL(ftrace_graph_stub)

#endif



	bctr			/* jump after _mcount site */



_GLOBAL(ftrace_stub)

	blr



#ifdef CONFIG_LIVEPATCH

	/*

	 * This function runs in the mcount context, between two functions. As

	 * such it can only clobber registers which are volatile and used in

	 * function linkage.

	 *

	 * We get here when a function A, calls another function B, but B has

	 * been live patched with a new function C.

	 *

	 * On entry:

	 *  - we have no stack frame and can not allocate one

	 *  - LR points back to the original caller (in A)

	 *  - CTR holds the new NIP in C

	 *  - r0 & r12 are free

	 *

	 * r0 can't be used as the base register for a DS-form load or store, so

	 * we temporarily shuffle r1 (stack pointer) into r0 and then put it back.

	 */

livepatch_handler:

	CURRENT_THREAD_INFO(r12, r1)



	/* Save stack pointer into r0 */

	mr	r0, r1



	/* Allocate 3 x 8 bytes */

	ld	r1, TI_livepatch_sp(r12)

	addi	r1, r1, 24

	std	r1, TI_livepatch_sp(r12)



	/* Save toc & real LR on livepatch stack */

	std	r2,  -24(r1)

	mflr	r12

	std	r12, -16(r1)



	/* Store stack end marker */

	lis     r12, STACK_END_MAGIC@h

	ori     r12, r12, STACK_END_MAGIC@l

	std	r12, -8(r1)



	/* Restore real stack pointer */

	mr	r1, r0



	/* Put ctr in r12 for global entry and branch there */

	mfctr	r12

	bctrl



	/*

	 * Now we are returning from the patched function to the original

	 * caller A. We are free to use r0 and r12, and we can use r2 until we

	 * restore it.

	 */



	CURRENT_THREAD_INFO(r12, r1)



	/* Save stack pointer into r0 */

	mr	r0, r1



	ld	r1, TI_livepatch_sp(r12)



	/* Check stack marker hasn't been trashed */

	lis     r2,  STACK_END_MAGIC@h

	ori     r2,  r2, STACK_END_MAGIC@l

	ld	r12, -8(r1)

1:	tdne	r12, r2

	EMIT_BUG_ENTRY 1b, __FILE__, __LINE__ - 1, 0



	/* Restore LR & toc from livepatch stack */

	ld	r12, -16(r1)

	mtlr	r12

	ld	r2,  -24(r1)



	/* Pop livepatch stack frame */

	CURRENT_THREAD_INFO(r12, r0)

	subi	r1, r1, 24

	std	r1, TI_livepatch_sp(r12)



	/* Restore real stack pointer */

	mr	r1, r0



	/* Return to original caller of live patched function */

	blr

#endif /* CONFIG_LIVEPATCH */



#endif /* CONFIG_DYNAMIC_FTRACE */



#ifdef CONFIG_FUNCTION_GRAPH_TRACER

_GLOBAL(ftrace_graph_caller)

	stdu	r1, -112(r1)

	/* with -mprofile-kernel, parameter regs are still alive at _mcount */

	std	r10, 104(r1)

	std	r9, 96(r1)

	std	r8, 88(r1)

	std	r7, 80(r1)

	std	r6, 72(r1)

	std	r5, 64(r1)

	std	r4, 56(r1)

	std	r3, 48(r1)



	/* Save callee's TOC in the ABI compliant location */

	std	r2, 24(r1)

	ld	r2, PACATOC(r13)	/* get kernel TOC in r2 */



	mfctr	r4		/* ftrace_caller has moved local addr here */

	std	r4, 40(r1)

	mflr	r3		/* ftrace_caller has restored LR from stack */

	subi	r4, r4, MCOUNT_INSN_SIZE



	bl	prepare_ftrace_return

	nop



	/*

	 * prepare_ftrace_return gives us the address we divert to.

	 * Change the LR to this.

	 */

	mtlr	r3



	ld	r0, 40(r1)

	mtctr	r0

	ld	r10, 104(r1)

	ld	r9, 96(r1)

	ld	r8, 88(r1)

	ld	r7, 80(r1)

	ld	r6, 72(r1)

	ld	r5, 64(r1)

	ld	r4, 56(r1)

	ld	r3, 48(r1)



	/* Restore callee's TOC */

	ld	r2, 24(r1)



	addi	r1, r1, 112

	mflr	r0

	std	r0, LRSAVE(r1)

	bctr

#endif /* CONFIG_FUNCTION_GRAPH_TRACER */

arch/powerpc/kernel/trace/ftrace_64_pg.S

0 → 100644
+68 −0
Original line number Diff line number Diff line 
/*

 * Split from ftrace_64.S

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version

 * 2 of the License, or (at your option) any later version.

 */



#include <linux/magic.h>

#include <asm/ppc_asm.h>

#include <asm/asm-offsets.h>

#include <asm/ftrace.h>

#include <asm/ppc-opcode.h>

#include <asm/export.h>



#ifdef CONFIG_DYNAMIC_FTRACE

_GLOBAL_TOC(ftrace_caller)

	/* Taken from output of objdump from lib64/glibc */

	mflr	r3

	ld	r11, 0(r1)

	stdu	r1, -112(r1)

	std	r3, 128(r1)

	ld	r4, 16(r11)

	subi	r3, r3, MCOUNT_INSN_SIZE

.globl ftrace_call

ftrace_call:

	bl	ftrace_stub

	nop

#ifdef CONFIG_FUNCTION_GRAPH_TRACER

.globl ftrace_graph_call

ftrace_graph_call:

	b	ftrace_graph_stub

_GLOBAL(ftrace_graph_stub)

#endif

	ld	r0, 128(r1)

	mtlr	r0

	addi	r1, r1, 112



_GLOBAL(ftrace_stub)

	blr

#endif /* CONFIG_DYNAMIC_FTRACE */



#ifdef CONFIG_FUNCTION_GRAPH_TRACER

_GLOBAL(ftrace_graph_caller)

	/* load r4 with local address */

	ld	r4, 128(r1)

	subi	r4, r4, MCOUNT_INSN_SIZE



	/* Grab the LR out of the caller stack frame */

	ld	r11, 112(r1)

	ld	r3, 16(r11)



	bl	prepare_ftrace_return

	nop



	/*

	 * prepare_ftrace_return gives us the address we divert to.

	 * Change the LR in the callers stack frame to this.

	 */

	ld	r11, 112(r1)

	std	r3, 16(r11)



	ld	r0, 128(r1)

	mtlr	r0

	addi	r1, r1, 112

	blr

#endif /* CONFIG_FUNCTION_GRAPH_TRACER */

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