681 lines
18 KiB
C
681 lines
18 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Code for replacing ftrace calls with jumps.
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*
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* Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
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*
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* Thanks goes out to P.A. Semi, Inc for supplying me with a PPC64 box.
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*
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* Added function graph tracer code, taken from x86 that was written
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* by Frederic Weisbecker, and ported to PPC by Steven Rostedt.
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*
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*/
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#define pr_fmt(fmt) "ftrace-powerpc: " fmt
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#include <linux/spinlock.h>
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#include <linux/hardirq.h>
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#include <linux/uaccess.h>
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#include <linux/module.h>
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#include <linux/ftrace.h>
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#include <linux/percpu.h>
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#include <linux/init.h>
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#include <linux/list.h>
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#include <asm/cacheflush.h>
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#include <asm/text-patching.h>
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#include <asm/ftrace.h>
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#include <asm/syscall.h>
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#include <asm/inst.h>
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#include <asm/sections.h>
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#define NUM_FTRACE_TRAMPS 2
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static unsigned long ftrace_tramps[NUM_FTRACE_TRAMPS];
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unsigned long ftrace_call_adjust(unsigned long addr)
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{
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if (addr >= (unsigned long)__exittext_begin && addr < (unsigned long)__exittext_end)
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return 0;
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if (IS_ENABLED(CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY) &&
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!IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE)) {
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addr += MCOUNT_INSN_SIZE;
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if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS))
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addr += MCOUNT_INSN_SIZE;
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}
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return addr;
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}
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static ppc_inst_t ftrace_create_branch_inst(unsigned long ip, unsigned long addr, int link)
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{
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ppc_inst_t op;
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WARN_ON(!is_offset_in_branch_range(addr - ip));
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create_branch(&op, (u32 *)ip, addr, link ? BRANCH_SET_LINK : 0);
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return op;
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}
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static inline int ftrace_read_inst(unsigned long ip, ppc_inst_t *op)
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{
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if (copy_inst_from_kernel_nofault(op, (void *)ip)) {
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pr_err("0x%lx: fetching instruction failed\n", ip);
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return -EFAULT;
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}
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return 0;
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}
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static inline int ftrace_validate_inst(unsigned long ip, ppc_inst_t inst)
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{
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ppc_inst_t op;
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int ret;
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ret = ftrace_read_inst(ip, &op);
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if (!ret && !ppc_inst_equal(op, inst)) {
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pr_err("0x%lx: expected (%08lx) != found (%08lx)\n",
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ip, ppc_inst_as_ulong(inst), ppc_inst_as_ulong(op));
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ret = -EINVAL;
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}
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return ret;
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}
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static inline int ftrace_modify_code(unsigned long ip, ppc_inst_t old, ppc_inst_t new)
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{
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int ret = ftrace_validate_inst(ip, old);
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if (!ret && !ppc_inst_equal(old, new))
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ret = patch_instruction((u32 *)ip, new);
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return ret;
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}
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static int is_bl_op(ppc_inst_t op)
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{
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return (ppc_inst_val(op) & ~PPC_LI_MASK) == PPC_RAW_BL(0);
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}
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static unsigned long find_ftrace_tramp(unsigned long ip)
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{
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int i;
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for (i = 0; i < NUM_FTRACE_TRAMPS; i++)
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if (!ftrace_tramps[i])
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continue;
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else if (is_offset_in_branch_range(ftrace_tramps[i] - ip))
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return ftrace_tramps[i];
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return 0;
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}
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#ifdef CONFIG_MODULES
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static unsigned long ftrace_lookup_module_stub(unsigned long ip, unsigned long addr)
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{
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struct module *mod = NULL;
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preempt_disable();
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mod = __module_text_address(ip);
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preempt_enable();
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if (!mod)
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pr_err("No module loaded at addr=%lx\n", ip);
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return (addr == (unsigned long)ftrace_caller ? mod->arch.tramp : mod->arch.tramp_regs);
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}
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#else
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static unsigned long ftrace_lookup_module_stub(unsigned long ip, unsigned long addr)
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{
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return 0;
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}
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#endif
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static unsigned long ftrace_get_ool_stub(struct dyn_ftrace *rec)
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{
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#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE
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return rec->arch.ool_stub;
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#else
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BUILD_BUG();
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#endif
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}
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static int ftrace_get_call_inst(struct dyn_ftrace *rec, unsigned long addr, ppc_inst_t *call_inst)
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{
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unsigned long ip;
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unsigned long stub;
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if (IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE))
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ip = ftrace_get_ool_stub(rec) + MCOUNT_INSN_SIZE; /* second instruction in stub */
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else
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ip = rec->ip;
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if (!is_offset_in_branch_range(addr - ip) && addr != FTRACE_ADDR &&
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addr != FTRACE_REGS_ADDR) {
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/* This can only happen with ftrace direct */
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if (!IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS)) {
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pr_err("0x%lx (0x%lx): Unexpected target address 0x%lx\n",
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ip, rec->ip, addr);
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return -EINVAL;
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}
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addr = FTRACE_ADDR;
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}
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if (is_offset_in_branch_range(addr - ip))
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/* Within range */
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stub = addr;
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else if (core_kernel_text(ip))
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/* We would be branching to one of our ftrace stubs */
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stub = find_ftrace_tramp(ip);
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else
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stub = ftrace_lookup_module_stub(ip, addr);
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if (!stub) {
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pr_err("0x%lx (0x%lx): No ftrace stubs reachable\n", ip, rec->ip);
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return -EINVAL;
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}
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*call_inst = ftrace_create_branch_inst(ip, stub, 1);
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return 0;
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}
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static int ftrace_init_ool_stub(struct module *mod, struct dyn_ftrace *rec)
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{
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#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE
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static int ool_stub_text_index, ool_stub_text_end_index, ool_stub_inittext_index;
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int ret = 0, ool_stub_count, *ool_stub_index;
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ppc_inst_t inst;
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/*
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* See ftrace_entry.S if changing the below instruction sequence, as we rely on
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* decoding the last branch instruction here to recover the correct function ip.
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*/
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struct ftrace_ool_stub *ool_stub, ool_stub_template = {
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.insn = {
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PPC_RAW_MFLR(_R0),
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PPC_RAW_NOP(), /* bl ftrace_caller */
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PPC_RAW_MTLR(_R0),
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PPC_RAW_NOP() /* b rec->ip + 4 */
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}
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};
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WARN_ON(rec->arch.ool_stub);
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if (is_kernel_inittext(rec->ip)) {
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ool_stub = ftrace_ool_stub_inittext;
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ool_stub_index = &ool_stub_inittext_index;
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ool_stub_count = ftrace_ool_stub_inittext_count;
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} else if (is_kernel_text(rec->ip)) {
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/*
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* ftrace records are sorted, so we first use up the stub area within .text
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* (ftrace_ool_stub_text) before using the area at the end of .text
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* (ftrace_ool_stub_text_end), unless the stub is out of range of the record.
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*/
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if (ool_stub_text_index >= ftrace_ool_stub_text_count ||
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!is_offset_in_branch_range((long)rec->ip -
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(long)&ftrace_ool_stub_text[ool_stub_text_index])) {
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ool_stub = ftrace_ool_stub_text_end;
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ool_stub_index = &ool_stub_text_end_index;
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ool_stub_count = ftrace_ool_stub_text_end_count;
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} else {
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ool_stub = ftrace_ool_stub_text;
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ool_stub_index = &ool_stub_text_index;
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ool_stub_count = ftrace_ool_stub_text_count;
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}
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#ifdef CONFIG_MODULES
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} else if (mod) {
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ool_stub = mod->arch.ool_stubs;
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ool_stub_index = &mod->arch.ool_stub_index;
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ool_stub_count = mod->arch.ool_stub_count;
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#endif
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} else {
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return -EINVAL;
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}
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ool_stub += (*ool_stub_index)++;
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if (WARN_ON(*ool_stub_index > ool_stub_count))
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return -EINVAL;
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if (!is_offset_in_branch_range((long)rec->ip - (long)&ool_stub->insn[0]) ||
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!is_offset_in_branch_range((long)(rec->ip + MCOUNT_INSN_SIZE) -
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(long)&ool_stub->insn[3])) {
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pr_err("%s: ftrace ool stub out of range (%p -> %p).\n",
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__func__, (void *)rec->ip, (void *)&ool_stub->insn[0]);
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return -EINVAL;
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}
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rec->arch.ool_stub = (unsigned long)&ool_stub->insn[0];
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/* bl ftrace_caller */
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if (!mod)
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ret = ftrace_get_call_inst(rec, (unsigned long)ftrace_caller, &inst);
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#ifdef CONFIG_MODULES
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else
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/*
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* We can't use ftrace_get_call_inst() since that uses
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* __module_text_address(rec->ip) to look up the module.
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* But, since the module is not fully formed at this stage,
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* the lookup fails. We know the target though, so generate
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* the branch inst directly.
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*/
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inst = ftrace_create_branch_inst(ftrace_get_ool_stub(rec) + MCOUNT_INSN_SIZE,
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mod->arch.tramp, 1);
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#endif
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ool_stub_template.insn[1] = ppc_inst_val(inst);
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/* b rec->ip + 4 */
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if (!ret && create_branch(&inst, &ool_stub->insn[3], rec->ip + MCOUNT_INSN_SIZE, 0))
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return -EINVAL;
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ool_stub_template.insn[3] = ppc_inst_val(inst);
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if (!ret)
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ret = patch_instructions((u32 *)ool_stub, (u32 *)&ool_stub_template,
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sizeof(ool_stub_template), false);
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return ret;
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#else /* !CONFIG_PPC_FTRACE_OUT_OF_LINE */
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BUILD_BUG();
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#endif
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}
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#ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS
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static const struct ftrace_ops *powerpc_rec_get_ops(struct dyn_ftrace *rec)
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{
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const struct ftrace_ops *ops = NULL;
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if (rec->flags & FTRACE_FL_CALL_OPS_EN) {
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ops = ftrace_find_unique_ops(rec);
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WARN_ON_ONCE(!ops);
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}
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if (!ops)
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ops = &ftrace_list_ops;
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return ops;
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}
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static int ftrace_rec_set_ops(struct dyn_ftrace *rec, const struct ftrace_ops *ops)
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{
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if (IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE))
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return patch_ulong((void *)(ftrace_get_ool_stub(rec) - sizeof(unsigned long)),
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(unsigned long)ops);
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else
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return patch_ulong((void *)(rec->ip - MCOUNT_INSN_SIZE - sizeof(unsigned long)),
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(unsigned long)ops);
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}
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static int ftrace_rec_set_nop_ops(struct dyn_ftrace *rec)
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{
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return ftrace_rec_set_ops(rec, &ftrace_nop_ops);
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}
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static int ftrace_rec_update_ops(struct dyn_ftrace *rec)
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{
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return ftrace_rec_set_ops(rec, powerpc_rec_get_ops(rec));
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}
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#else
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static int ftrace_rec_set_nop_ops(struct dyn_ftrace *rec) { return 0; }
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static int ftrace_rec_update_ops(struct dyn_ftrace *rec) { return 0; }
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#endif
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#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
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int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, unsigned long addr)
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{
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/* This should never be called since we override ftrace_replace_code() */
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WARN_ON(1);
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return -EINVAL;
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}
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#endif
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int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
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{
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ppc_inst_t old, new;
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unsigned long ip = rec->ip;
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int ret = 0;
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/* This can only ever be called during module load */
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if (WARN_ON(!IS_ENABLED(CONFIG_MODULES) || core_kernel_text(ip)))
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return -EINVAL;
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old = ppc_inst(PPC_RAW_NOP());
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if (IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE)) {
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ip = ftrace_get_ool_stub(rec) + MCOUNT_INSN_SIZE; /* second instruction in stub */
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ret = ftrace_get_call_inst(rec, (unsigned long)ftrace_caller, &old);
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}
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ret |= ftrace_get_call_inst(rec, addr, &new);
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if (!ret)
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ret = ftrace_modify_code(ip, old, new);
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ret = ftrace_rec_update_ops(rec);
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if (ret)
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return ret;
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if (!ret && IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE))
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ret = ftrace_modify_code(rec->ip, ppc_inst(PPC_RAW_NOP()),
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ppc_inst(PPC_RAW_BRANCH((long)ftrace_get_ool_stub(rec) - (long)rec->ip)));
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return ret;
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}
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int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr)
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{
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/*
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* This should never be called since we override ftrace_replace_code(),
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* as well as ftrace_init_nop()
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*/
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WARN_ON(1);
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return -EINVAL;
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}
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void ftrace_replace_code(int enable)
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{
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ppc_inst_t old, new, call_inst, new_call_inst;
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ppc_inst_t nop_inst = ppc_inst(PPC_RAW_NOP());
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unsigned long ip, new_addr, addr;
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struct ftrace_rec_iter *iter;
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struct dyn_ftrace *rec;
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int ret = 0, update;
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for_ftrace_rec_iter(iter) {
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rec = ftrace_rec_iter_record(iter);
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ip = rec->ip;
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if (rec->flags & FTRACE_FL_DISABLED && !(rec->flags & FTRACE_FL_ENABLED))
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continue;
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addr = ftrace_get_addr_curr(rec);
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new_addr = ftrace_get_addr_new(rec);
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update = ftrace_update_record(rec, enable);
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if (IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE) && update != FTRACE_UPDATE_IGNORE) {
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ip = ftrace_get_ool_stub(rec) + MCOUNT_INSN_SIZE;
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ret = ftrace_get_call_inst(rec, (unsigned long)ftrace_caller, &nop_inst);
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if (ret)
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goto out;
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}
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switch (update) {
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case FTRACE_UPDATE_IGNORE:
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default:
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continue;
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case FTRACE_UPDATE_MODIFY_CALL:
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ret = ftrace_get_call_inst(rec, new_addr, &new_call_inst);
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ret |= ftrace_get_call_inst(rec, addr, &call_inst);
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ret |= ftrace_rec_update_ops(rec);
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old = call_inst;
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new = new_call_inst;
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break;
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case FTRACE_UPDATE_MAKE_NOP:
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ret = ftrace_get_call_inst(rec, addr, &call_inst);
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ret |= ftrace_rec_set_nop_ops(rec);
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old = call_inst;
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new = nop_inst;
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break;
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case FTRACE_UPDATE_MAKE_CALL:
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ret = ftrace_get_call_inst(rec, new_addr, &call_inst);
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ret |= ftrace_rec_update_ops(rec);
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old = nop_inst;
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new = call_inst;
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break;
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}
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if (!ret)
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ret = ftrace_modify_code(ip, old, new);
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if (!ret && IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE) &&
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(update == FTRACE_UPDATE_MAKE_NOP || update == FTRACE_UPDATE_MAKE_CALL)) {
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/* Update the actual ftrace location */
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call_inst = ppc_inst(PPC_RAW_BRANCH((long)ftrace_get_ool_stub(rec) -
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(long)rec->ip));
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nop_inst = ppc_inst(PPC_RAW_NOP());
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ip = rec->ip;
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if (update == FTRACE_UPDATE_MAKE_NOP)
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ret = ftrace_modify_code(ip, call_inst, nop_inst);
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else
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ret = ftrace_modify_code(ip, nop_inst, call_inst);
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if (ret)
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goto out;
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}
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if (ret)
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goto out;
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}
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out:
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if (ret)
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ftrace_bug(ret, rec);
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return;
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}
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int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec)
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{
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unsigned long addr, ip = rec->ip;
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ppc_inst_t old, new;
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int ret = 0;
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/* Verify instructions surrounding the ftrace location */
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if (IS_ENABLED(CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY)) {
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/* Expect nops */
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if (!IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE))
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ret = ftrace_validate_inst(ip - 4, ppc_inst(PPC_RAW_NOP()));
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if (!ret)
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ret = ftrace_validate_inst(ip, ppc_inst(PPC_RAW_NOP()));
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} else if (IS_ENABLED(CONFIG_PPC32)) {
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/* Expected sequence: 'mflr r0', 'stw r0,4(r1)', 'bl _mcount' */
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ret = ftrace_validate_inst(ip - 8, ppc_inst(PPC_RAW_MFLR(_R0)));
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if (ret)
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return ret;
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ret = ftrace_modify_code(ip - 4, ppc_inst(PPC_RAW_STW(_R0, _R1, 4)),
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ppc_inst(PPC_RAW_NOP()));
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} else if (IS_ENABLED(CONFIG_MPROFILE_KERNEL)) {
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/* Expected sequence: 'mflr r0', ['std r0,16(r1)'], 'bl _mcount' */
|
|
ret = ftrace_read_inst(ip - 4, &old);
|
|
if (!ret && !ppc_inst_equal(old, ppc_inst(PPC_RAW_MFLR(_R0)))) {
|
|
/* Gcc v5.x emit the additional 'std' instruction, gcc v6.x don't */
|
|
ret = ftrace_validate_inst(ip - 8, ppc_inst(PPC_RAW_MFLR(_R0)));
|
|
if (ret)
|
|
return ret;
|
|
ret = ftrace_modify_code(ip - 4, ppc_inst(PPC_RAW_STD(_R0, _R1, 16)),
|
|
ppc_inst(PPC_RAW_NOP()));
|
|
}
|
|
} else {
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* Set up out-of-line stub */
|
|
if (IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE))
|
|
return ftrace_init_ool_stub(mod, rec);
|
|
|
|
/* Nop-out the ftrace location */
|
|
new = ppc_inst(PPC_RAW_NOP());
|
|
addr = MCOUNT_ADDR;
|
|
if (IS_ENABLED(CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY)) {
|
|
/* we instead patch-in the 'mflr r0' */
|
|
old = ppc_inst(PPC_RAW_NOP());
|
|
new = ppc_inst(PPC_RAW_MFLR(_R0));
|
|
ret = ftrace_modify_code(ip - 4, old, new);
|
|
} else if (is_offset_in_branch_range(addr - ip)) {
|
|
/* Within range */
|
|
old = ftrace_create_branch_inst(ip, addr, 1);
|
|
ret = ftrace_modify_code(ip, old, new);
|
|
} else if (core_kernel_text(ip) || (IS_ENABLED(CONFIG_MODULES) && mod)) {
|
|
/*
|
|
* We would be branching to a linker-generated stub, or to the module _mcount
|
|
* stub. Let's just confirm we have a 'bl' here.
|
|
*/
|
|
ret = ftrace_read_inst(ip, &old);
|
|
if (ret)
|
|
return ret;
|
|
if (!is_bl_op(old)) {
|
|
pr_err("0x%lx: expected (bl) != found (%08lx)\n", ip, ppc_inst_as_ulong(old));
|
|
return -EINVAL;
|
|
}
|
|
ret = patch_instruction((u32 *)ip, new);
|
|
} else {
|
|
return -EINVAL;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
int ftrace_update_ftrace_func(ftrace_func_t func)
|
|
{
|
|
unsigned long ip = (unsigned long)(&ftrace_call);
|
|
ppc_inst_t old, new;
|
|
int ret;
|
|
|
|
/*
|
|
* When using CALL_OPS, the function to call is associated with the
|
|
* call site, and we don't have a global function pointer to update.
|
|
*/
|
|
if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS))
|
|
return 0;
|
|
|
|
old = ppc_inst_read((u32 *)&ftrace_call);
|
|
new = ftrace_create_branch_inst(ip, ppc_function_entry(func), 1);
|
|
ret = ftrace_modify_code(ip, old, new);
|
|
|
|
/* Also update the regs callback function */
|
|
if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) && !ret) {
|
|
ip = (unsigned long)(&ftrace_regs_call);
|
|
old = ppc_inst_read((u32 *)&ftrace_regs_call);
|
|
new = ftrace_create_branch_inst(ip, ppc_function_entry(func), 1);
|
|
ret = ftrace_modify_code(ip, old, new);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Use the default ftrace_modify_all_code, but without
|
|
* stop_machine().
|
|
*/
|
|
void arch_ftrace_update_code(int command)
|
|
{
|
|
ftrace_modify_all_code(command);
|
|
}
|
|
|
|
void ftrace_free_init_tramp(void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < NUM_FTRACE_TRAMPS && ftrace_tramps[i]; i++)
|
|
if (ftrace_tramps[i] == (unsigned long)ftrace_tramp_init) {
|
|
ftrace_tramps[i] = 0;
|
|
return;
|
|
}
|
|
}
|
|
|
|
static void __init add_ftrace_tramp(unsigned long tramp)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < NUM_FTRACE_TRAMPS; i++)
|
|
if (!ftrace_tramps[i]) {
|
|
ftrace_tramps[i] = tramp;
|
|
return;
|
|
}
|
|
}
|
|
|
|
int __init ftrace_dyn_arch_init(void)
|
|
{
|
|
unsigned int *tramp[] = { ftrace_tramp_text, ftrace_tramp_init };
|
|
unsigned long addr = FTRACE_REGS_ADDR;
|
|
long reladdr;
|
|
int i;
|
|
u32 stub_insns[] = {
|
|
#ifdef CONFIG_PPC_KERNEL_PCREL
|
|
/* pla r12,addr */
|
|
PPC_PREFIX_MLS | __PPC_PRFX_R(1),
|
|
PPC_INST_PADDI | ___PPC_RT(_R12),
|
|
PPC_RAW_MTCTR(_R12),
|
|
PPC_RAW_BCTR()
|
|
#elif defined(CONFIG_PPC64)
|
|
PPC_RAW_LD(_R12, _R13, offsetof(struct paca_struct, kernel_toc)),
|
|
PPC_RAW_ADDIS(_R12, _R12, 0),
|
|
PPC_RAW_ADDI(_R12, _R12, 0),
|
|
PPC_RAW_MTCTR(_R12),
|
|
PPC_RAW_BCTR()
|
|
#else
|
|
PPC_RAW_LIS(_R12, 0),
|
|
PPC_RAW_ADDI(_R12, _R12, 0),
|
|
PPC_RAW_MTCTR(_R12),
|
|
PPC_RAW_BCTR()
|
|
#endif
|
|
};
|
|
|
|
if (IS_ENABLED(CONFIG_PPC_KERNEL_PCREL)) {
|
|
for (i = 0; i < 2; i++) {
|
|
reladdr = addr - (unsigned long)tramp[i];
|
|
|
|
if (reladdr >= (long)SZ_8G || reladdr < -(long)SZ_8G) {
|
|
pr_err("Address of %ps out of range of pcrel address.\n",
|
|
(void *)addr);
|
|
return -1;
|
|
}
|
|
|
|
memcpy(tramp[i], stub_insns, sizeof(stub_insns));
|
|
tramp[i][0] |= IMM_H18(reladdr);
|
|
tramp[i][1] |= IMM_L(reladdr);
|
|
add_ftrace_tramp((unsigned long)tramp[i]);
|
|
}
|
|
} else if (IS_ENABLED(CONFIG_PPC64)) {
|
|
reladdr = addr - kernel_toc_addr();
|
|
|
|
if (reladdr >= (long)SZ_2G || reladdr < -(long long)SZ_2G) {
|
|
pr_err("Address of %ps out of range of kernel_toc.\n",
|
|
(void *)addr);
|
|
return -1;
|
|
}
|
|
|
|
for (i = 0; i < 2; i++) {
|
|
memcpy(tramp[i], stub_insns, sizeof(stub_insns));
|
|
tramp[i][1] |= PPC_HA(reladdr);
|
|
tramp[i][2] |= PPC_LO(reladdr);
|
|
add_ftrace_tramp((unsigned long)tramp[i]);
|
|
}
|
|
} else {
|
|
for (i = 0; i < 2; i++) {
|
|
memcpy(tramp[i], stub_insns, sizeof(stub_insns));
|
|
tramp[i][0] |= PPC_HA(addr);
|
|
tramp[i][1] |= PPC_LO(addr);
|
|
add_ftrace_tramp((unsigned long)tramp[i]);
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
|
|
struct ftrace_ops *op, struct ftrace_regs *fregs)
|
|
{
|
|
unsigned long sp = arch_ftrace_regs(fregs)->regs.gpr[1];
|
|
int bit;
|
|
|
|
if (unlikely(ftrace_graph_is_dead()))
|
|
goto out;
|
|
|
|
if (unlikely(atomic_read(¤t->tracing_graph_pause)))
|
|
goto out;
|
|
|
|
bit = ftrace_test_recursion_trylock(ip, parent_ip);
|
|
if (bit < 0)
|
|
goto out;
|
|
|
|
if (!function_graph_enter(parent_ip, ip, 0, (unsigned long *)sp))
|
|
parent_ip = ppc_function_entry(return_to_handler);
|
|
|
|
ftrace_test_recursion_unlock(bit);
|
|
out:
|
|
arch_ftrace_regs(fregs)->regs.link = parent_ip;
|
|
}
|
|
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
|