[PATCH v2 1/1] ARM64/ftrace: ftrace support on ARM64.
Ganapatrao Kulkarni
ganapatrao.kulkarni at caviumnetworks.com
Thu Oct 17 04:00:30 EDT 2013
From: Ganapatrao Kulkarni <ganapatrao.kulkarni at cavium.com>
This patch adds the support for ftrace on ARM64.
This patch implements arm64 support for function trace,
dynamic function trace, function graph trace
and dynamic function graph trace.
This patch has been tested on Simulator.
Signed-off-by: Ganapatrao Kulkarni <ganapatrao.kulkarni at cavium.com>
---
arch/arm64/Kconfig | 5 +
arch/arm64/include/asm/ftrace.h | 78 +++++++++++++++
arch/arm64/include/asm/stacktrace.h | 1 +
arch/arm64/kernel/Makefile | 10 +-
arch/arm64/kernel/arm64ksyms.c | 5 +
arch/arm64/kernel/entry.S | 187 +++++++++++++++++++++++++++++++++++
arch/arm64/kernel/ftrace.c | 191 ++++++++++++++++++++++++++++++++++++
arch/arm64/kernel/insn.c | 48 +++++++++
arch/arm64/kernel/insn.h | 38 +++++++
arch/arm64/kernel/return_address.c | 67 +++++++++++++
scripts/recordmcount.c | 4 +
scripts/recordmcount.h | 3 +-
scripts/recordmcount.pl | 5 +
13 files changed, 640 insertions(+), 2 deletions(-)
create mode 100644 arch/arm64/include/asm/ftrace.h
create mode 100644 arch/arm64/kernel/ftrace.c
create mode 100644 arch/arm64/kernel/insn.c
create mode 100644 arch/arm64/kernel/insn.h
create mode 100644 arch/arm64/kernel/return_address.c
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 9737e97..84bb061 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -18,10 +18,15 @@ config ARM64
select GENERIC_TIME_VSYSCALL
select HARDIRQS_SW_RESEND
select HAVE_ARCH_TRACEHOOK
+ select HAVE_C_RECORDMCOUNT
select HAVE_DEBUG_BUGVERBOSE
select HAVE_DEBUG_KMEMLEAK
select HAVE_DMA_API_DEBUG
select HAVE_DMA_ATTRS
+ select HAVE_DYNAMIC_FTRACE
+ select HAVE_FTRACE_MCOUNT_RECORD
+ select HAVE_FUNCTION_GRAPH_TRACER
+ select HAVE_FUNCTION_TRACER
select HAVE_GENERIC_DMA_COHERENT
select HAVE_GENERIC_HARDIRQS
select HAVE_HW_BREAKPOINT if PERF_EVENTS
diff --git a/arch/arm64/include/asm/ftrace.h b/arch/arm64/include/asm/ftrace.h
new file mode 100644
index 0000000..9ba9bf2
--- /dev/null
+++ b/arch/arm64/include/asm/ftrace.h
@@ -0,0 +1,78 @@
+/*
+ * Based on arch/arm/include/asm/ftrace.h
+ *
+ * Copyright (C) 2008 Abhishek Sagar <sagar.abhishek at gmail.com>
+ * Copyright (C) 2010 Rabin Vincent <rabin at rab.in>
+ * Copyright (C) 2013 Cavium Inc
+ * Author: Ganapatrao Kulkarni <ganapatrao.kulkarni at cavium.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+#ifndef _ASM_ARM_FTRACE
+#define _ASM_ARM_FTRACE
+
+#ifdef CONFIG_FUNCTION_TRACER
+#define MCOUNT_ADDR ((unsigned long) _mcount)
+#define MCOUNT_INSN_SIZE 4 /* sizeof mcount call */
+#define ARM64_NOP_OPCODE 0xd503201f /* nop */
+
+#ifndef __ASSEMBLY__
+extern void _mcount(void);
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+
+extern unsigned long ftrace_graph_call;
+extern void ftrace_graph_caller(void);
+
+struct dyn_arch_ftrace {
+ /* No extra data needed */
+};
+
+static inline unsigned long ftrace_call_adjust(unsigned long addr)
+{
+ return addr;
+}
+
+#endif /* ifdef CONFIG_DYNAMIC_FTRACE */
+#endif /* ifndef__ASSEMBLY__ */
+#endif /* ifdef CONFIG_FUNCTION_TRACER */
+
+#ifndef __ASSEMBLY__
+
+#ifdef CONFIG_FRAME_POINTER
+
+void *return_address(unsigned int);
+
+#else /* #ifdef CONFIG_FRAME_POINTER */
+
+extern inline void *return_address(unsigned int level)
+{
+ return NULL;
+}
+
+#endif /* #ifdef CONFIG_FRAME_POINTER */
+
+#define HAVE_ARCH_CALLER_ADDR
+
+#define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
+#define CALLER_ADDR1 ((unsigned long)return_address(1))
+#define CALLER_ADDR2 ((unsigned long)return_address(2))
+#define CALLER_ADDR3 ((unsigned long)return_address(3))
+#define CALLER_ADDR4 ((unsigned long)return_address(4))
+#define CALLER_ADDR5 ((unsigned long)return_address(5))
+#define CALLER_ADDR6 ((unsigned long)return_address(6))
+
+#endif /* ifndef __ASSEMBLY__ */
+
+#endif /* _ASM_ARM_FTRACE */
diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h
index 7318f6d..fec7e84 100644
--- a/arch/arm64/include/asm/stacktrace.h
+++ b/arch/arm64/include/asm/stacktrace.h
@@ -19,6 +19,7 @@
struct stackframe {
unsigned long fp;
unsigned long sp;
+ unsigned long lr;
unsigned long pc;
};
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index 7b4b564..678c218 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -5,17 +5,25 @@
CPPFLAGS_vmlinux.lds := -DTEXT_OFFSET=$(TEXT_OFFSET)
AFLAGS_head.o := -DTEXT_OFFSET=$(TEXT_OFFSET)
+ifdef CONFIG_FUNCTION_TRACER
+CFLAGS_REMOVE_ftrace.o = -pg
+CFLAGS_REMOVE_insn.o = -pg
+CFLAGS_REMOVE_return_address.o = -pg
+endif
+
# Object file lists.
arm64-obj-y := cputable.o debug-monitors.o entry.o irq.o fpsimd.o \
entry-fpsimd.o process.o ptrace.o setup.o signal.o \
sys.o stacktrace.o time.o traps.o io.o vdso.o \
- hyp-stub.o psci.o
+ hyp-stub.o psci.o return_address.o
arm64-obj-$(CONFIG_COMPAT) += sys32.o kuser32.o signal32.o \
sys_compat.o
arm64-obj-$(CONFIG_MODULES) += arm64ksyms.o module.o
arm64-obj-$(CONFIG_SMP) += smp.o smp_spin_table.o smp_psci.o
arm64-obj-$(CONFIG_HW_PERF_EVENTS) += perf_event.o
+arm64-obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o insn.o
+arm64-obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o insn.o
arm64-obj-$(CONFIG_HAVE_HW_BREAKPOINT)+= hw_breakpoint.o
arm64-obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
diff --git a/arch/arm64/kernel/arm64ksyms.c b/arch/arm64/kernel/arm64ksyms.c
index 41b4f62..c5f8887 100644
--- a/arch/arm64/kernel/arm64ksyms.c
+++ b/arch/arm64/kernel/arm64ksyms.c
@@ -58,3 +58,8 @@ EXPORT_SYMBOL(clear_bit);
EXPORT_SYMBOL(test_and_clear_bit);
EXPORT_SYMBOL(change_bit);
EXPORT_SYMBOL(test_and_change_bit);
+
+#ifdef CONFIG_FUNCTION_TRACER
+EXPORT_SYMBOL(_mcount);
+#endif
+
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 6ad781b..1cc80b3 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -28,6 +28,7 @@
#include <asm/thread_info.h>
#include <asm/unistd.h>
#include <asm/unistd32.h>
+#include <asm/ftrace.h>
/*
* Bad Abort numbers
@@ -690,3 +691,189 @@ ENDPROC(sys_rt_sigreturn_wrapper)
ENTRY(handle_arch_irq)
.quad 0
+
+
+#ifdef CONFIG_FUNCTION_TRACER
+/*
+ * When compiling with -pg, gcc inserts a call to the mcount routine at the
+ * start of every function. In _mcount, apart from the function's address (in
+ * lr), we need to get hold of the function's caller's address.
+ *
+ * Make sure, your GNU compiler inserts the _mcount and x30(lr) stored beneath
+ * the stack frame when compiled with -pg option as below,
+ *
+ * ## echo 'main(){}' | ./aarch64-linux-gnu-gcc -x c -S -o - - -pg
+ * .cpu thunder+fp+simd+crypto+crc
+ * .file ""
+ * .global _mcount
+ * .text
+ * .align 2
+ * .global main
+ * .type main, %function
+ * main:
+ * stp x29, x30, [sp, -16]!
+ * add x29, sp, 0
+ * mov x0, x30
+ * bl _mcount
+ * ldp x29, x30, [sp], 16
+ * ret
+ * .size main, .-main
+ *
+ *
+ * Stack content after mcount_enter
+ *
+ * |------------------| x29 + 16
+ * | |
+ * | x30 | <= lr of instrumented func
+ * | |
+ * |------------------| x29 + 8
+ * | |
+ * | x29 | <= sp of instrumented func
+ * | |
+ * |------------------| x29 + 0 <= frame pointer/stack base address
+ * | |
+ * | x2 | <= used as temporary register
+ * | |
+ * |------------------| x29 - 8
+ * | |
+ * | x1 | <= used as temporary register
+ * | |
+ * |------------------| x29 - 16
+ * | |
+ * | lr | <= lr of _mcount/__ftrace_caller
+ * | |
+ * |------------------| x29 - 24
+ * | |
+ * | x0 | <= used as temporary register
+ * | |
+ * |------------------| x29 - 32
+ *
+ */
+
+.macro mcount_adjust_addr xd, xn
+ sub \xd, \xn, #MCOUNT_INSN_SIZE
+.endm
+
+.macro mcount_enter
+ push x1, x2
+ push x0, lr
+.endm
+
+.macro mcount_exit
+ pop x0, lr
+ pop x1, x2
+ ret
+.endm
+
+.macro __mcount
+ mcount_enter
+ ldr x0, =ftrace_trace_function
+ ldr x2, [x0]
+ adr x0, .Lftrace_stub
+ cmp x0, x2
+ bne 1f
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ ldr x1, =ftrace_graph_return
+ ldr x2, [x1]
+ cmp x0, x2
+ bne ftrace_graph_caller
+
+ ldr x1, =ftrace_graph_entry
+ ldr x2, [x1]
+ ldr x0, =ftrace_graph_entry_stub
+ cmp x0, x2
+ bne ftrace_graph_caller
+#endif
+ mcount_exit
+
+1: ldr x1, [x29, #8] /* lr of instrumented func */
+ mcount_adjust_addr x0, lr /* lr of _mcount */
+ adr lr, 2f
+ br x2
+2: mcount_exit
+.endm
+
+.macro __ftrace_caller
+ mcount_enter
+ ldr x1, [x29, #8] /* lr of instrumented func */
+#ifdef CONFIG_DYNAMIC_FTRACE
+ /* lr of _mcount, called from __ftrace_caller, saved in mcount_enter */
+ ldr x0, [x29, #-24]
+ mcount_adjust_addr x0, x0
+#else
+ /* lr of _moucnt, called from __mcount, untouched lr */
+ mcount_adjust_addr x0, lr
+#endif
+ .globl ftrace_call
+ftrace_call:
+ nop
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ .globl ftrace_graph_call
+ftrace_graph_call:
+ nop
+#endif
+ mcount_exit
+.endm
+
+.macro __ftrace_graph_caller
+ /* &lr of instrumented routine (&parent) */
+ add x0, x29, #8
+#ifdef CONFIG_DYNAMIC_FTRACE
+ /* lr of _mcount, called from __ftrace_caller, saved in mcount_enter */
+ ldr x1, [x29, #-24]
+ mcount_adjust_addr x1, x1
+#else
+ /* lr of _moucnt, called from __mcount, untouched lr */
+ mcount_adjust_addr x1, lr
+#endif
+ ldr x2, [x29] /* frame pointer*/
+ push x29, x30 /* push x29 and x30 */
+ mov x29, sp /* updated fp to current sp */
+ bl prepare_ftrace_return
+ pop x29, x30 /* restore x29 and x30 */
+ mcount_exit
+.endm
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ .globl return_to_handler
+return_to_handler:
+ push x0, x1
+ mov x0, x29 /* frame pointer */
+ push x29, x30 /* push x29 and x30 */
+ mov x29, sp /* updated fp to current sp */
+ bl ftrace_return_to_handler
+ pop x29, x30 /* restore x29 and x30 */
+ mov lr, x0
+ pop x0, x1
+ ret
+#endif
+
+ENTRY(_mcount)
+#ifdef CONFIG_DYNAMIC_FTRACE
+ ret
+#else
+ __mcount
+#endif
+ENDPROC(_mcount)
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+ENTRY(ftrace_caller)
+ __ftrace_caller
+ENDPROC(ftrace_caller)
+#endif
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ENTRY(ftrace_graph_caller)
+ __ftrace_graph_caller
+ENDPROC(ftrace_graph_caller)
+#endif
+
+ENTRY(ftrace_stub)
+.Lftrace_stub:
+ ret
+ENDPROC(ftrace_stub)
+
+.purgem mcount_enter
+.purgem mcount_exit
+#endif /* CONFIG_FUNCTION_TRACER */
diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c
new file mode 100644
index 0000000..f8da28f
--- /dev/null
+++ b/arch/arm64/kernel/ftrace.c
@@ -0,0 +1,191 @@
+/*
+ * Dynamic and Graph function tracing support.
+ *
+ * Based on arch/arm/kernel/ftrace.c
+ *
+ * Copyright (C) 2008 Abhishek Sagar <sagar.abhishek at gmail.com>
+ * Copyright (C) 2010 Rabin Vincent <rabin at rab.in>
+ * Copyright (C) 2013 Cavium Inc
+ * Author: Ganapatrao Kulkarni <ganapatrao.kulkarni at cavium.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Defines low-level handling of mcount calls when the kernel
+ * is compiled with the -pg flag. When using dynamic ftrace, the
+ * mcount call-sites get patched with NOP till they are enabled.
+ * All code mutation routines here are called under stop_machine().
+ */
+
+#include <linux/ftrace.h>
+#include <linux/uaccess.h>
+
+#include <asm/cacheflush.h>
+#include <asm/ftrace.h>
+
+#include "insn.h"
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+
+static unsigned long ftrace_nop_replace(struct dyn_ftrace *rec)
+{
+ return ARM64_NOP_OPCODE;
+}
+
+static unsigned long ftrace_call_replace(unsigned long pc, unsigned long addr)
+{
+ return arm_gen_branch_link(pc, addr);
+}
+
+static int ftrace_modify_code(unsigned long pc, unsigned int old,
+ unsigned int new, bool validate)
+{
+ unsigned int replaced;
+
+#ifdef CONFIG_CPU_BIG_ENDIAN
+ old = swab32(old);
+ new = swab32(new);
+#endif
+
+ if (validate) {
+ if (probe_kernel_read(&replaced, (void *)pc, MCOUNT_INSN_SIZE))
+ return -EFAULT;
+
+ if (replaced != old)
+ return -EINVAL;
+ }
+
+ if (probe_kernel_write((void *)pc, &new, MCOUNT_INSN_SIZE))
+ return -EPERM;
+
+ flush_icache_range(pc, pc + MCOUNT_INSN_SIZE);
+
+ return 0;
+}
+
+int ftrace_update_ftrace_func(ftrace_func_t func)
+{
+ unsigned long pc;
+ unsigned int new;
+ int ret = 0;
+
+ pc = (unsigned long)&ftrace_call;
+ new = ftrace_call_replace(pc, (unsigned long)func);
+ ret = ftrace_modify_code(pc, 0, new, false);
+
+ return ret;
+}
+
+int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned int new, old;
+ unsigned long ip = rec->ip;
+ int ret;
+
+ old = ftrace_nop_replace(rec);
+ new = ftrace_call_replace(ip, addr);
+ ret = ftrace_modify_code(rec->ip, old, new, true);
+
+ return ret;
+}
+
+int ftrace_make_nop(struct module *mod,
+ struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned long ip = rec->ip;
+ unsigned int old;
+ unsigned int new;
+ int ret;
+
+ old = ftrace_call_replace(ip, addr);
+ new = ftrace_nop_replace(rec);
+ ret = ftrace_modify_code(ip, old, new, true);
+
+ return ret;
+}
+
+int __init ftrace_dyn_arch_init(void *data)
+{
+ *(unsigned long *)data = 0;
+
+ return 0;
+}
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
+ unsigned long frame_pointer)
+{
+ unsigned long return_hooker = (unsigned long) &return_to_handler;
+ struct ftrace_graph_ent trace;
+ unsigned long old;
+ int err;
+
+ if (unlikely(atomic_read(¤t->tracing_graph_pause)))
+ return;
+
+ old = *parent;
+ *parent = return_hooker;
+
+ trace.func = self_addr;
+ trace.depth = current->curr_ret_stack + 1;
+
+ /* Only trace if the calling function expects to */
+ if (!ftrace_graph_entry(&trace)) {
+ *parent = old;
+ return;
+ }
+
+ err = ftrace_push_return_trace(old, self_addr, &trace.depth,
+ frame_pointer);
+ if (err == -EBUSY) {
+ *parent = old;
+ return;
+ }
+}
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+static int __ftrace_modify_caller(unsigned long *callsite,
+ void (*func) (void), bool enable)
+{
+ unsigned long caller_fn = (unsigned long) func;
+ unsigned long pc = (unsigned long) callsite;
+ unsigned int branch = arm_gen_branch(pc, caller_fn);
+ unsigned int nop = ARM64_NOP_OPCODE;
+ unsigned int old = enable ? nop : branch;
+ unsigned int new = enable ? branch : nop;
+
+ return ftrace_modify_code(pc, old, new, true);
+}
+
+static int ftrace_modify_graph_caller(bool enable)
+{
+ int ret;
+
+ ret = __ftrace_modify_caller(&ftrace_graph_call,
+ ftrace_graph_caller,
+ enable);
+
+ return ret;
+}
+
+int ftrace_enable_ftrace_graph_caller(void)
+{
+ return ftrace_modify_graph_caller(true);
+}
+
+int ftrace_disable_ftrace_graph_caller(void)
+{
+ return ftrace_modify_graph_caller(false);
+}
+#endif /* CONFIG_DYNAMIC_FTRACE */
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c
new file mode 100644
index 0000000..02843e1
--- /dev/null
+++ b/arch/arm64/kernel/insn.c
@@ -0,0 +1,48 @@
+/*
+ * Based on arch/arm/kernel/insn.c
+ *
+ * Copyright (C) 2013 Cavium Inc
+ * Author: Ganapatrao Kulkarni <ganapatrao.kulkarni at cavium.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <linux/bug.h>
+#include <linux/kernel.h>
+
+static unsigned int
+__arm_gen_branch_arm(unsigned long pc, unsigned long addr, bool link)
+{
+ unsigned int opcode = 0x14000000;
+ int offset;
+
+ if (link)
+ opcode |= 1 << 31;
+
+ offset = (long)addr - (long)(pc);
+ /* bl label on arm64 is of width 26 bits/imm26 */
+ if (unlikely(offset < -67108863 || offset > 67108859)) {
+ WARN_ON_ONCE(1);
+ return 0;
+ }
+
+ offset = (offset >> 2) & 0x03ffffff; /* imm26 */
+ return opcode | offset;
+}
+
+unsigned int
+__arm_gen_branch(unsigned long pc, unsigned long addr, bool link)
+{
+ return __arm_gen_branch_arm(pc, addr, link);
+}
diff --git a/arch/arm64/kernel/insn.h b/arch/arm64/kernel/insn.h
new file mode 100644
index 0000000..4deaef8
--- /dev/null
+++ b/arch/arm64/kernel/insn.h
@@ -0,0 +1,38 @@
+/*
+ * Based on arch/arm/kernel/insn.h
+ *
+ * Copyright (C) 2013 Cavium Inc
+ * Author: Ganapatrao Kulkarni <ganapatrao.kulkarni at cavium.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+#ifndef __ASM_ARM_INSN_H
+#define __ASM_ARM_INSN_H
+
+unsigned long
+__arm_gen_branch(unsigned long pc, unsigned long addr, bool link);
+
+static inline unsigned long
+arm_gen_branch(unsigned long pc, unsigned long addr)
+{
+ return __arm_gen_branch(pc, addr, false);
+}
+
+static inline unsigned long
+arm_gen_branch_link(unsigned long pc, unsigned long addr)
+{
+ return __arm_gen_branch(pc, addr, true);
+}
+
+#endif
diff --git a/arch/arm64/kernel/return_address.c b/arch/arm64/kernel/return_address.c
new file mode 100644
index 0000000..4e613cd
--- /dev/null
+++ b/arch/arm64/kernel/return_address.c
@@ -0,0 +1,67 @@
+/*
+ * Copy of arch/arm/kernel/return_address.c
+ *
+ * Copyright (C) 2009 Uwe Kleine-Koenig <u.kleine-koenig at pengutronix.de>
+ * for Pengutronix
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+#include <linux/export.h>
+#include <linux/ftrace.h>
+
+#ifdef CONFIG_FRAME_POINTER
+#include <linux/sched.h>
+
+#include <asm/stacktrace.h>
+
+struct return_address_data {
+ unsigned int level;
+ void *addr;
+};
+
+static int save_return_addr(struct stackframe *frame, void *d)
+{
+ struct return_address_data *data = d;
+
+ if (!data->level) {
+ data->addr = (void *)frame->pc;
+
+ return 1;
+ } else {
+ --data->level;
+ return 0;
+ }
+}
+
+void *return_address(unsigned int level)
+{
+ struct return_address_data data;
+ struct stackframe frame;
+ register unsigned long current_sp asm ("sp");
+
+ data.level = level + 2;
+ data.addr = NULL;
+
+ frame.fp = (unsigned long)__builtin_frame_address(0);
+ frame.sp = current_sp;
+ frame.lr = (unsigned long)__builtin_return_address(0);
+ frame.pc = (unsigned long)return_address;
+
+ walk_stackframe(&frame, save_return_addr, &data);
+
+ if (!data.level)
+ return data.addr;
+ else
+ return NULL;
+}
+#else /* ifdef CONFIG_FRAME_POINTER */
+
+void *return_address(unsigned int level)
+{
+ return NULL;
+}
+#endif /* ifdef CONFIG_FRAME_POINTER */
+EXPORT_SYMBOL_GPL(return_address);
+
diff --git a/scripts/recordmcount.c b/scripts/recordmcount.c
index 9c22317..b92d9f7 100644
--- a/scripts/recordmcount.c
+++ b/scripts/recordmcount.c
@@ -347,6 +347,10 @@ do_file(char const *const fname)
case EM_ARM: reltype = R_ARM_ABS32;
altmcount = "__gnu_mcount_nc";
break;
+ case EM_AARCH64:
+ reltype = R_AARCH64_ABS64;
+ altmcount = "_mcount";
+ break;
case EM_IA_64: reltype = R_IA64_IMM64; gpfx = '_'; break;
case EM_METAG: reltype = R_METAG_ADDR32;
altmcount = "_mcount_wrapper";
diff --git a/scripts/recordmcount.h b/scripts/recordmcount.h
index 9d1421e..5b7752c 100644
--- a/scripts/recordmcount.h
+++ b/scripts/recordmcount.h
@@ -433,7 +433,8 @@ static unsigned find_secsym_ndx(unsigned const txtndx,
/* avoid STB_WEAK */
&& (STB_LOCAL == st_bind || STB_GLOBAL == st_bind)) {
/* function symbols on ARM have quirks, avoid them */
- if (w2(ehdr->e_machine) == EM_ARM
+ if ((w2(ehdr->e_machine) == EM_ARM
+ || w2(ehdr->e_machine) == EM_AARCH64)
&& ELF_ST_TYPE(symp->st_info) == STT_FUNC)
continue;
diff --git a/scripts/recordmcount.pl b/scripts/recordmcount.pl
index 858966a..294c077 100755
--- a/scripts/recordmcount.pl
+++ b/scripts/recordmcount.pl
@@ -279,6 +279,11 @@ if ($arch eq "x86_64") {
$mcount_regex = "^\\s*([0-9a-fA-F]+):\\s*R_ARM_(CALL|PC24|THM_CALL)" .
"\\s+(__gnu_mcount_nc|mcount)\$";
+} elsif ($arch eq "arm64") {
+ $alignment = 2;
+ $section_type = '%progbits';
+ $mcount_regex = "^\\s*([0-9a-fA-F]+):\\s*R_AARCH64_CALL26\\s+__mcount\$";
+
} elsif ($arch eq "ia64") {
$mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s_mcount\$";
$type = "data8";
--
1.8.1.4
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