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kvanheesnickalcock
kvanhees
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dtrace, arm: arm64 port
This provides an arm64 implementation of DTrace. Signed-off-by: Nick Alcock <[email protected]> Signed-off-by: Kris Van Hees <[email protected]> Signed-off-by: Tomas Jedlicka <[email protected]> Signed-off-by: Eugene Loh <[email protected]> Signed-off-by: David Mc Lean <[email protected]> Signed-off-by: Vincent Lim <[email protected]>
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-14
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‎arch/arm64/Kconfig

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@@ -282,6 +282,9 @@ config PGTABLE_LEVELS
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config ARCH_SUPPORTS_UPROBES
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def_bool y
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config ARCH_SUPPORTS_DTRACE
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def_bool y
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config ARCH_PROC_KCORE_TEXT
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def_bool y
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‎arch/arm64/dtrace/Makefile.arch

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#
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# Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
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#
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DTARCHDIR = ../arch/arm64/dtrace
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ccflags-y += -Iarch/arm64/dtrace/include -Idtrace
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dtrace-obj += dtrace_asm_arm64.o dtrace_isa_arm64.o
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fasttrap-obj += fasttrap_arm64.o
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fbt-obj += fbt_arm64.o
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sdt-obj += sdt_arm64.o
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dtrace-y += $(addprefix $(DTARCHDIR)/, $(dtrace-obj))
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fasttrap-y += $(addprefix $(DTARCHDIR)/, $(fasttrap-obj))
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fbt-y += $(addprefix $(DTARCHDIR)/, $(fbt-obj))
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sdt-y += $(addprefix $(DTARCHDIR)/, $(sdt-obj))

‎arch/arm64/dtrace/dtrace_asm_arm64.S

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/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Dynamic Tracing for Linux - ARM64 specific assembly
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*
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* Copyright (c) 2017 Oracle and/or its affiliates. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/linkage.h>
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ENTRY(dtrace_caller)
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mov x0, #-1
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ret
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ENDPROC(dtrace_caller)
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ENTRY(dtrace_copy)
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ret
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ENDPROC(dtrace_copy)
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ENTRY(dtrace_copystr)
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ret
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ENDPROC(dtrace_copystr)
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ENTRY(dtrace_fuword8_nocheck)
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ldrb w0, [x0]
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ret
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ENDPROC(dtrace_fuword8_nocheck)
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ENTRY(dtrace_fuword16_nocheck)
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ldrh w0, [x0]
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ret
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ENDPROC(dtrace_fuword16_nocheck)
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ENTRY(dtrace_fuword32_nocheck)
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ldr w0, [x0]
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ret
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ENDPROC(dtrace_fuword32_nocheck)
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ENTRY(dtrace_fuword64_nocheck)
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ldr x0, [x0]
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ret
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ENDPROC(dtrace_fuword64_nocheck)

‎arch/arm64/dtrace/dtrace_isa_arm64.c

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/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* FILE: dtrace_isa_arm64.c
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* DESCRIPTION: DTrace - arm64 architecture specific support functions
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*
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* Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <asm/stacktrace.h>
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#include <linux/ptrace.h>
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#include "dtrace.h"
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uintptr_t _userlimit = 0x0000ffffffffffffLL;
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void dtrace_copyin_arch(uintptr_t uaddr, uintptr_t kaddr, size_t size,
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volatile uint16_t *flags)
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{
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}
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void dtrace_copyinstr_arch(uintptr_t uaddr, uintptr_t kaddr, size_t size,
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volatile uint16_t *flags)
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{
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}
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void dtrace_copyout(uintptr_t uaddr, uintptr_t kaddr, size_t size,
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volatile uint16_t *flags)
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{
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}
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void dtrace_copyoutstr(uintptr_t uaddr, uintptr_t kaddr, size_t size,
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volatile uint16_t *flags)
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{
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}
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#define DTRACE_FUWORD(bits) \
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uint##bits##_t dtrace_fuword##bits(void *uaddr) \
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{ \
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extern uint##bits##_t dtrace_fuword##bits##_nocheck(void *);\
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\
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if ((uintptr_t)uaddr > _userlimit) { \
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DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR); \
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this_cpu_core->cpuc_dtrace_illval = (uintptr_t)uaddr; \
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} \
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\
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return dtrace_fuword##bits##_nocheck(uaddr); \
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}
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DTRACE_FUWORD(8)
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DTRACE_FUWORD(16)
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DTRACE_FUWORD(32)
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DTRACE_FUWORD(64)
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static int dtrace_unwind_frame(struct task_struct *task,
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struct stackframe *frame)
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{
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unsigned long fp = frame->fp;
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if (fp & 0xf)
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return -EINVAL;
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DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
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frame->fp = READ_ONCE_NOCHECK(*(unsigned long *)(fp));
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frame->pc = READ_ONCE_NOCHECK(*(unsigned long *)(fp + 8));
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DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
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if (!frame->fp && !frame->pc)
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return -EINVAL;
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return 0;
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}
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uint64_t dtrace_getarg(int argno, int aframes)
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{
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uint64_t *st;
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uint64_t val;
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int i;
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struct stackframe frame;
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struct task_struct *task = current;
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if (argno < 7)
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return 0;
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if (this_cpu_core->cpu_dtrace_regs)
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st = (uint64_t *)this_cpu_core->cpu_dtrace_regs->regs[29];
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else {
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frame.fp = (unsigned long)__builtin_frame_address(0);
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frame.pc = (unsigned long)dtrace_getarg;
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aframes += 1; /* Count this function. */
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for (i = 0; i < aframes; i++) {
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if (dtrace_unwind_frame(task, &frame) < 0)
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break;
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}
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/*
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* If we cannot traverse the expected number of stack frames,
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* there is something wrong with the stack.
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*/
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if (i < aframes) {
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DTRACE_CPUFLAG_SET(CPU_DTRACE_BADSTACK);
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return 0;
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}
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st = (uint64_t *)frame.fp;
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}
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/*
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* The first 7 arguments (arg0 through arg6) are passed in registers
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* to dtrace_probe(). The remaining arguments (arg7 through arg9) are
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* passed on the stack.
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*
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* Stack layout:
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* bp[0] = pushed fp from caller
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* bp[1] = return address
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* bp[2] = 8th argument (arg7 -> argno = 7)
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* bp[3] = 9th argument (arg8 -> argno = 8)
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* ...
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*/
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DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
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val = READ_ONCE_NOCHECK(st[2 + (argno - 7)]);
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DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
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return val;
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}
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ulong_t dtrace_getreg(struct task_struct *task, uint_t reg)
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{
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struct pt_regs *rp = task_pt_regs(task);
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return regs_get_register(rp, reg * sizeof(uint64_t));
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}
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void pdata_init(dtrace_module_t *pdata, struct module *mp)
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{
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/*
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* Throw away existing data as we don't support reusal at
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* the moment.
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*/
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if (mp->pdata != NULL)
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pdata_cleanup(pdata, mp);
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pdata->sdt_tab = NULL;
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pdata->fbt_tab = NULL;
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}
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void pdata_cleanup(dtrace_module_t *pdata, struct module *mp)
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{
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if (pdata->sdt_tab != NULL)
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dtrace_free_text(pdata->sdt_tab);
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if (pdata->fbt_tab != NULL)
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dtrace_free_text(pdata->fbt_tab);
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}

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