[PATCH v3 1/2] powerpc: split ftrace bits into a separate file
Naveen N. Rao
naveen.n.rao at linux.vnet.ibm.com
Wed Feb 22 06:01:01 AEDT 2017
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 at ellerman.id.au>
Signed-off-by: Naveen N. Rao <naveen.n.rao at linux.vnet.ibm.com>
---
arch/powerpc/kernel/Makefile | 9 +-
arch/powerpc/kernel/entry_32.S | 107 -------
arch/powerpc/kernel/entry_64.S | 380 -------------------------
arch/powerpc/kernel/trace/Makefile | 24 ++
arch/powerpc/kernel/{ => trace}/ftrace.c | 0
arch/powerpc/kernel/trace/ftrace_32.S | 118 ++++++++
arch/powerpc/kernel/trace/ftrace_64.S | 391 ++++++++++++++++++++++++++
arch/powerpc/kernel/{ => trace}/trace_clock.c | 0
8 files changed, 534 insertions(+), 495 deletions(-)
create mode 100644 arch/powerpc/kernel/trace/Makefile
rename arch/powerpc/kernel/{ => trace}/ftrace.c (100%)
create mode 100644 arch/powerpc/kernel/trace/ftrace_32.S
create mode 100644 arch/powerpc/kernel/trace/ftrace_64.S
rename arch/powerpc/kernel/{ => trace}/trace_clock.c (100%)
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index a048b37b9b27..e1a04237f09d 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -29,8 +29,6 @@ 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 $(CC_FLAGS_FTRACE)
endif
@@ -122,10 +120,7 @@ obj64-$(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
@@ -146,8 +141,6 @@ 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
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index f3e4fc1c1b4d..5a2a13bd2193 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -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>
@@ -1319,109 +1318,3 @@ 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 */
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 6432d4bf08c8..9b541d22595a 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -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>
@@ -1173,381 +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 & pt_regs->link */
- std r7, _NIP(r1)
- std r7, _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 at toc@ha
- addi r3,r3,function_trace_op at 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 callee's TOC */
- ld r2, 24(r1)
-
- /* Pop our stack frame */
- addi r1, r1, SWITCH_FRAME_SIZE
-
- /* Restore original LR for return to B */
- ld r0, LRSAVE(r1)
- mtlr r0
-
-#ifdef CONFIG_LIVEPATCH
- /* Based on the cmpd above, if the NIP was altered handle livepatch */
- bne- livepatch_handler
-#endif
-
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
- stdu r1, -112(r1)
-.globl ftrace_graph_call
-ftrace_graph_call:
- b ftrace_graph_stub
-_GLOBAL(ftrace_graph_stub)
- addi r1, r1, 112
-#endif
-
- ld r0,LRSAVE(r1) /* restore callee's lr at _mcount site */
- mtlr r0
- 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 at h
- ori r12, r12, STACK_END_MAGIC at 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 at h
- ori r2, r2, STACK_END_MAGIC at 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)
- /* 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 */
diff --git a/arch/powerpc/kernel/trace/Makefile b/arch/powerpc/kernel/trace/Makefile
new file mode 100644
index 000000000000..5f5a35254a9b
--- /dev/null
+++ b/arch/powerpc/kernel/trace/Makefile
@@ -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
diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
similarity index 100%
rename from arch/powerpc/kernel/ftrace.c
rename to arch/powerpc/kernel/trace/ftrace.c
diff --git a/arch/powerpc/kernel/trace/ftrace_32.S b/arch/powerpc/kernel/trace/ftrace_32.S
new file mode 100644
index 000000000000..afef2c076282
--- /dev/null
+++ b/arch/powerpc/kernel/trace/ftrace_32.S
@@ -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 */
diff --git a/arch/powerpc/kernel/trace/ftrace_64.S b/arch/powerpc/kernel/trace/ftrace_64.S
new file mode 100644
index 000000000000..df47433b8e13
--- /dev/null
+++ b/arch/powerpc/kernel/trace/ftrace_64.S
@@ -0,0 +1,391 @@
+/*
+ * 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 & pt_regs->link */
+ std r7, _NIP(r1)
+ std r7, _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 at toc@ha
+ addi r3,r3,function_trace_op at 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 callee's TOC */
+ ld r2, 24(r1)
+
+ /* Pop our stack frame */
+ addi r1, r1, SWITCH_FRAME_SIZE
+
+ /* Restore original LR for return to B */
+ ld r0, LRSAVE(r1)
+ mtlr r0
+
+#ifdef CONFIG_LIVEPATCH
+ /* Based on the cmpd above, if the NIP was altered handle livepatch */
+ bne- livepatch_handler
+#endif
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ stdu r1, -112(r1)
+.globl ftrace_graph_call
+ftrace_graph_call:
+ b ftrace_graph_stub
+_GLOBAL(ftrace_graph_stub)
+ addi r1, r1, 112
+#endif
+
+ ld r0,LRSAVE(r1) /* restore callee's lr at _mcount site */
+ mtlr r0
+ 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 at h
+ ori r12, r12, STACK_END_MAGIC at 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 at h
+ ori r2, r2, STACK_END_MAGIC at 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)
+ /* 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 */
diff --git a/arch/powerpc/kernel/trace_clock.c b/arch/powerpc/kernel/trace/trace_clock.c
similarity index 100%
rename from arch/powerpc/kernel/trace_clock.c
rename to arch/powerpc/kernel/trace/trace_clock.c
--
2.11.0
More information about the Linuxppc-dev
mailing list