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powerpc: Split ftrace bits into a separate file

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entry_*.S now includes a lot more than just kernel entry/exit code. As a
first step at cleaning this up, let's split out the ftrace bits into
separate files. Also move all related tracing code into a new trace/
subdirectory.

No functional changes.

Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Naveen N. Rao 2017-04-25 19:25:53 +05:30 committed by Michael Ellerman
parent 2505820f7c
commit 7853f9c029
8 changed files with 532 additions and 493 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
arch/powerpc/kernel/Makefile
View File

@ -25,8 +25,6 @@ CFLAGS_REMOVE_cputable.o = -mno-sched-epilog $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_prom_init.o = -mno-sched-epilog $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_btext.o = -mno-sched-epilog $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_prom.o = -mno-sched-epilog $(CC_FLAGS_FTRACE)
# do not trace tracer code
CFLAGS_REMOVE_ftrace.o = -mno-sched-epilog $(CC_FLAGS_FTRACE)
# timers used by tracing
CFLAGS_REMOVE_time.o = -mno-sched-epilog $(CC_FLAGS_FTRACE)
endif
@ -119,10 +117,7 @@ obj64-$(CONFIG_AUDIT) += compat_audit.o
obj-$(CONFIG_PPC_IO_WORKAROUNDS) += io-workarounds.o
obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o
obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o
obj-$(CONFIG_FTRACE_SYSCALLS) += ftrace.o
obj-$(CONFIG_TRACING) += trace_clock.o
obj-y += trace/
ifneq ($(CONFIG_PPC_INDIRECT_PIO),y)
obj-y += iomap.o
@ -143,8 +138,6 @@ obj-$(CONFIG_KVM_GUEST) += kvm.o kvm_emul.o
# Disable GCOV & sanitizers in odd or sensitive code
GCOV_PROFILE_prom_init.o := n
UBSAN_SANITIZE_prom_init.o := n
GCOV_PROFILE_ftrace.o := n
UBSAN_SANITIZE_ftrace.o := n
GCOV_PROFILE_machine_kexec_64.o := n
UBSAN_SANITIZE_machine_kexec_64.o := n
GCOV_PROFILE_machine_kexec_32.o := n

107
arch/powerpc/kernel/entry_32.S
View File

@ -31,7 +31,6 @@
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
#include <asm/unistd.h>
#include <asm/ftrace.h>
#include <asm/ptrace.h>
#include <asm/export.h>
@ -1315,109 +1314,3 @@ machine_check_in_rtas:
/* XXX load up BATs and panic */
#endif /* CONFIG_PPC_RTAS */
#ifdef CONFIG_FUNCTION_TRACER
#ifdef CONFIG_DYNAMIC_FTRACE
_GLOBAL(mcount)
_GLOBAL(_mcount)
/*
* It is required that _mcount on PPC32 must preserve the
* link register. But we have r0 to play with. We use r0
* to push the return address back to the caller of mcount
* into the ctr register, restore the link register and
* then jump back using the ctr register.
*/
mflr r0
mtctr r0
lwz r0, 4(r1)
mtlr r0
bctr
_GLOBAL(ftrace_caller)
MCOUNT_SAVE_FRAME
/* r3 ends up with link register */
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
MCOUNT_RESTORE_FRAME
/* old link register ends up in ctr reg */
bctr
#else
_GLOBAL(mcount)
_GLOBAL(_mcount)
MCOUNT_SAVE_FRAME
subi r3, r3, MCOUNT_INSN_SIZE
LOAD_REG_ADDR(r5, ftrace_trace_function)
lwz r5,0(r5)
mtctr r5
bctrl
nop
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
b ftrace_graph_caller
#endif
MCOUNT_RESTORE_FRAME
bctr
#endif
EXPORT_SYMBOL(_mcount)
_GLOBAL(ftrace_stub)
blr
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
_GLOBAL(ftrace_graph_caller)
/* load r4 with local address */
lwz r4, 44(r1)
subi r4, r4, MCOUNT_INSN_SIZE
/* Grab the LR out of the caller stack frame */
lwz r3,52(r1)
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.
*/
stw r3,52(r1)
MCOUNT_RESTORE_FRAME
/* old link register ends up in ctr reg */
bctr
_GLOBAL(return_to_handler)
/* need to save return values */
stwu r1, -32(r1)
stw r3, 20(r1)
stw r4, 16(r1)
stw r31, 12(r1)
mr r31, r1
bl ftrace_return_to_handler
nop
/* return value has real return address */
mtlr r3
lwz r3, 20(r1)
lwz r4, 16(r1)
lwz r31,12(r1)
lwz r1, 0(r1)
/* Jump back to real return address */
blr
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
#endif /* CONFIG_FUNCTION_TRACER */

378
arch/powerpc/kernel/entry_64.S
View File

@ -20,7 +20,6 @@
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/magic.h>
#include <asm/unistd.h>
#include <asm/processor.h>
#include <asm/page.h>
@ -33,7 +32,6 @@
#include <asm/bug.h>
#include <asm/ptrace.h>
#include <asm/irqflags.h>
#include <asm/ftrace.h>
#include <asm/hw_irq.h>
#include <asm/context_tracking.h>
#include <asm/tm.h>
@ -1173,379 +1171,3 @@ _GLOBAL(enter_prom)
ld r0,16(r1)
mtlr r0
blr
#ifdef CONFIG_FUNCTION_TRACER
#ifdef CONFIG_DYNAMIC_FTRACE
_GLOBAL(mcount)
_GLOBAL(_mcount)
EXPORT_SYMBOL(_mcount)
mflr r12
mtctr r12
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
_GLOBAL_TOC(_mcount)
EXPORT_SYMBOL(_mcount)
/* 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
LOAD_REG_ADDR(r5,ftrace_trace_function)
ld r5,0(r5)
ld r5,0(r5)
mtctr r5
bctrl
nop
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
b ftrace_graph_caller
#endif
ld r0, 128(r1)
mtlr r0
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)
std r3, -24(r1)
/* save TOC */
std r2, -16(r1)
std r31, -8(r1)
mr r31, r1
stdu r1, -112(r1)
/*
* We might be called from a module.
* Switch to our TOC to run inside the core kernel.
*/
ld r2, PACATOC(r13)
bl ftrace_return_to_handler
nop
/* return value has real return address */
mtlr r3
ld r1, 0(r1)
ld r4, -32(r1)
ld r3, -24(r1)
ld r2, -16(r1)
ld r31, -8(r1)
/* Jump back to real return address */
blr
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
#endif /* CONFIG_FUNCTION_TRACER */

24
arch/powerpc/kernel/trace/Makefile Normal file
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@ -0,0 +1,24 @@
#
# Makefile for the powerpc trace subsystem
#
subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror
ifdef CONFIG_FUNCTION_TRACER
# do not trace tracer code
CFLAGS_REMOVE_ftrace.o = -mno-sched-epilog $(CC_FLAGS_FTRACE)
endif
obj32-$(CONFIG_FUNCTION_TRACER) += ftrace_32.o
obj64-$(CONFIG_FUNCTION_TRACER) += ftrace_64.o
obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o
obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o
obj-$(CONFIG_FTRACE_SYSCALLS) += ftrace.o
obj-$(CONFIG_TRACING) += trace_clock.o
obj-$(CONFIG_PPC64) += $(obj64-y)
obj-$(CONFIG_PPC32) += $(obj32-y)
# Disable GCOV & sanitizers in odd or sensitive code
GCOV_PROFILE_ftrace.o := n
UBSAN_SANITIZE_ftrace.o := n

0
arch/powerpc/kernel/ftrace.c → arch/powerpc/kernel/trace/ftrace.c
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118
arch/powerpc/kernel/trace/ftrace_32.S Normal file
View File

@ -0,0 +1,118 @@
/*
* Split from entry_32.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/reg.h>
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
#include <asm/ftrace.h>
#include <asm/export.h>
#ifdef CONFIG_DYNAMIC_FTRACE
_GLOBAL(mcount)
_GLOBAL(_mcount)
/*
* It is required that _mcount on PPC32 must preserve the
* link register. But we have r0 to play with. We use r0
* to push the return address back to the caller of mcount
* into the ctr register, restore the link register and
* then jump back using the ctr register.
*/
mflr r0
mtctr r0
lwz r0, 4(r1)
mtlr r0
bctr
_GLOBAL(ftrace_caller)
MCOUNT_SAVE_FRAME
/* r3 ends up with link register */
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
MCOUNT_RESTORE_FRAME
/* old link register ends up in ctr reg */
bctr
#else
_GLOBAL(mcount)
_GLOBAL(_mcount)
MCOUNT_SAVE_FRAME
subi r3, r3, MCOUNT_INSN_SIZE
LOAD_REG_ADDR(r5, ftrace_trace_function)
lwz r5,0(r5)
mtctr r5
bctrl
nop
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
b ftrace_graph_caller
#endif
MCOUNT_RESTORE_FRAME
bctr
#endif
EXPORT_SYMBOL(_mcount)
_GLOBAL(ftrace_stub)
blr
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
_GLOBAL(ftrace_graph_caller)
/* load r4 with local address */
lwz r4, 44(r1)
subi r4, r4, MCOUNT_INSN_SIZE
/* Grab the LR out of the caller stack frame */
lwz r3,52(r1)
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.
*/
stw r3,52(r1)
MCOUNT_RESTORE_FRAME
/* old link register ends up in ctr reg */
bctr
_GLOBAL(return_to_handler)
/* need to save return values */
stwu r1, -32(r1)
stw r3, 20(r1)
stw r4, 16(r1)
stw r31, 12(r1)
mr r31, r1
bl ftrace_return_to_handler
nop
/* return value has real return address */
mtlr r3
lwz r3, 20(r1)
lwz r4, 16(r1)
lwz r31,12(r1)
lwz r1, 0(r1)
/* Jump back to real return address */
blr
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */

389
arch/powerpc/kernel/trace/ftrace_64.S Normal file
View File

@ -0,0 +1,389 @@
/*
* Split from entry_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(mcount)
_GLOBAL(_mcount)
EXPORT_SYMBOL(_mcount)
mflr r12
mtctr r12
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
_GLOBAL_TOC(_mcount)
EXPORT_SYMBOL(_mcount)
/* 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
LOAD_REG_ADDR(r5,ftrace_trace_function)
ld r5,0(r5)
ld r5,0(r5)
mtctr r5
bctrl
nop
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
b ftrace_graph_caller
#endif
ld r0, 128(r1)
mtlr r0
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)
std r3, -24(r1)
/* save TOC */
std r2, -16(r1)
std r31, -8(r1)
mr r31, r1
stdu r1, -112(r1)
/*
* We might be called from a module.
* Switch to our TOC to run inside the core kernel.
*/
ld r2, PACATOC(r13)
bl ftrace_return_to_handler
nop
/* return value has real return address */
mtlr r3
ld r1, 0(r1)
ld r4, -32(r1)
ld r3, -24(r1)
ld r2, -16(r1)
ld r31, -8(r1)
/* Jump back to real return address */
blr
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */

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arch/powerpc/kernel/trace_clock.c → arch/powerpc/kernel/trace/trace_clock.c
View File