// SPDX-License-Identifier: GPL-2.0
/*
* Code for replacing ftrace calls with jumps.
*
* Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
*
* Thanks goes out to P.A. Semi, Inc for supplying me with a PPC64 box.
*
* Added function graph tracer code, taken from x86 that was written
* by Frederic Weisbecker, and ported to PPC by Steven Rostedt.
*
*/
#define pr_fmt(fmt) "ftrace-powerpc: " fmt
#include <linux/spinlock.h>
#include <linux/hardirq.h>
#include <linux/uaccess.h>
#include <linux/module.h>
#include <linux/ftrace.h>
#include <linux/percpu.h>
#include <linux/init.h>
#include <linux/list.h>
#include <asm/cacheflush.h>
#include <asm/code-patching.h>
#include <asm/ftrace.h>
#include <asm/syscall.h>
#include <asm/inst.h>
/*
* We generally only have a single long_branch tramp and at most 2 or 3 plt
* tramps generated. But, we don't use the plt tramps currently. We also allot
* 2 tramps after .text and .init.text. So, we only end up with around 3 usable
* tramps in total. Set aside 8 just to be sure.
*/
#define NUM_FTRACE_TRAMPS 8
static unsigned long ftrace_tramps[NUM_FTRACE_TRAMPS];
static ppc_inst_t
ftrace_call_replace(unsigned long ip, unsigned long addr, int link)
{
ppc_inst_t op;
addr = ppc_function_entry((void *)addr);
/* if (link) set op to 'bl' else 'b' */
create_branch(&op, (u32 *)ip, addr, link ? BRANCH_SET_LINK : 0);
return op;
}
static inline int
ftrace_modify_code(unsigned long ip, ppc_inst_t old, ppc_inst_t new)
{
ppc_inst_t replaced;
/*
* Note:
* We are paranoid about modifying text, as if a bug was to happen, it
* could cause us to read or write to someplace that could cause harm.
* Carefully read and modify the code with probe_kernel_*(), and make
* sure what we read is what we expected it to be before modifying it.
*/
/* read the text we want to modify */
if (copy_inst_from_kernel_nofault(&replaced, (void *)ip))
return -EFAULT;
/* Make sure it is what we expect it to be */
if (!ppc_inst_equal(replaced, old)) {
pr_err("%p: replaced (%08lx) != old (%08lx)", (void *)ip,
ppc_inst_as_ulong(replaced), ppc_inst_as_ulong(old));
return -EINVAL;
}
/* replace the text with the new text */
return patch_instruction((u32 *)ip, new);
}
/*
* Helper functions that are the same for both PPC64 and PPC32.
*/
static int test_24bit_addr(unsigned long ip, unsigned long addr)
{
addr = ppc_function_entry((void *)addr);
return is_offset_in_branch_range(addr - ip);
}
static int is_bl_op(ppc_inst_t op)
{
return (ppc_inst_val(op) & ~PPC_LI_MASK) == PPC_RAW_BL(0);
}
static int is_b_op(ppc_inst_t op)
{
return (ppc_inst_val(op) & ~PPC_LI_MASK) == PPC_RAW_BRANCH(0);
}
static unsigned long find_bl_target(unsigned long ip, ppc_inst_t op)
{
int offset;
offset = PPC_LI(ppc_inst_val(op));
/* make it signed */
if (offset & 0x02000000)
offset |= 0xfe000000;
return ip + (long)offset;
}
#ifdef CONFIG_MODULES
static int
__ftrace_make_nop(struct module *mod,
struct dyn_ftrace *rec, unsigned long addr)
{
unsigned long entry, ptr, tramp;
unsigned long ip = rec->ip;
ppc_inst_t op, pop;
/* read where this goes */
if (copy_inst_from_kernel_nofault(&op, (void *)ip)) {
pr_err("Fetching opcode failed.\n");
return -EFAULT;
}
/* Make sure that this is still a 24bit jump */
if (!is_bl_op(op)) {
pr_err("Not expected bl: opcode is %08lx\n", ppc_inst_as_ulong(op));
return -EINVAL;
}
/* lets find where the pointer goes */
tramp = find_bl_target(ip, op);
pr_devel("ip:%lx jumps to %lx", ip, tramp);
if (module_trampoline_target(mod, tramp, &ptr)) {
pr_err("Failed to get trampoline target\n");
return -EFAULT;
}
pr_devel("trampoline target %lx", ptr);
entry = ppc_global_function_entry((void *)addr);
/* This should match what was called */
if (ptr != entry) {
pr_err("addr %lx does not match expected %lx\n", ptr, entry);
return -EINVAL;
}
if (IS_ENABLED(CONFIG_MPROFILE_KERNEL)) {
if (copy_inst_from_kernel_nofault(&op, (void *)(ip - 4))) {
pr_err("Fetching instruction at %lx failed.\n", ip - 4);
return -EFAULT;
}
/* We expect either a mflr r0, or a std r0, LRSAVE(r1) */
if (!ppc_inst_equal(op, ppc_inst(PPC_RAW_MFLR(_R0))) &&
!ppc_inst_equal(op, ppc_inst(PPC_INST_STD_LR))) {
pr_err("Unexpected instruction %08lx around bl _mcount\n",
ppc_inst_as_ulong(op));
return -EINVAL;
}
} else if (IS_ENABLED(CONFIG_PPC64)) {
/*
* Check what is in the next instruction. We can see ld r2,40(r1), but
* on first pass after boot we will see mflr r0.
*/
if (copy_inst_from_kernel_nofault(&op, (void *)(ip + 4))) {
pr_err("Fetching op failed.\n");
return -EFAULT;
}
if (!ppc_inst_equal(op, ppc_inst(PPC_INST_LD_TOC))) {
pr_err("Expected %08lx found %08lx\n", PPC_INST_LD_TOC,
ppc_inst_as_ulong(op));
return -EINVAL;
}
}
/*
* When using -mprofile-kernel or PPC32 there is no load to jump over.
*
* Otherwise our original call site looks like:
*
* bl <tramp>
* ld r2,XX(r1)
*
* Milton Miller pointed out that we can not simply nop the branch.
* If a task was preempted when calling a trace function, the nops
* will remove the way to restore the TOC in r2 and the r2 TOC will
* get corrupted.
*
* Use a b +8 to jump over the load.
*/
if (IS_ENABLED(CONFIG_MPROFILE_KERNEL) || IS_ENABLED(CONFIG_PPC32))
pop = ppc_inst(PPC_RAW_NOP());
else
pop = ppc_inst(PPC_RAW_BRANCH(8)); /* b +8 */
if (patch_instruction((u32 *)ip, pop)) {
pr_err("Patching NOP failed.\n");
return -EPERM;
}
return 0;
}
#else
static int __ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr)
{
return 0;
}
#endif /* CONFIG_MODULES */
static unsigned long find_ftrace_tramp(unsigned long ip)
{
int i;
/*
* We have the compiler generated long_branch tramps at the end
* and we prefer those
*/
for (i = NUM_FTRACE_TRAMPS - 1; i >= 0; i--)
if (!ftrace_tramps[i])
continue;
else if (is_offset_in_branch_range(ftrace_tramps[i] - ip))
return ftrace_tramps[i];
return 0;
}
static int 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 0;
}
return -1;
}
/*
* If this is a compiler generated long_branch trampoline (essentially, a
* trampoline that has a branch to _mcount()), we re-write the branch to
* instead go to ftrace_[regs_]caller() and note down the location of this
* trampoline.
*/
static int setup_mcount_compiler_tramp(unsigned long tramp)
{
int i;
ppc_inst_t op;
unsigned long ptr;
/* Is this a known long jump tramp? */
for (i = 0; i < NUM_FTRACE_TRAMPS; i++)
if (ftrace_tramps[i] == tramp)
return 0;
/* New trampoline -- read where this goes */
if (copy_inst_from_kernel_nofault(&op, (void *)tramp)) {
pr_debug("Fetching opcode failed.\n");
return -1;
}
/* Is this a 24 bit branch? */
if (!is_b_op(op)) {
pr_debug("Trampoline is not a long branch tramp.\n");
return -1;
}
/* lets find where the pointer goes */
ptr = find_bl_target(tramp, op);
if (ptr != ppc_global_function_entry((void *)_mcount)) {
pr_debug("Trampoline target %p is not _mcount\n", (void *)ptr);
return -1;
}
/* Let's re-write the tramp to go to ftrace_[regs_]caller */
if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS))
ptr = ppc_global_function_entry((void *)ftrace_regs_caller);
else
ptr = ppc_global_function_entry((void *)ftrace_caller);
if (patch_branch((u32 *)tramp, ptr, 0)) {
pr_debug("REL24 out of range!\n");
return -1;
}
if (add_ftrace_tramp(tramp)) {
pr_debug("No tramp locations left\n");
return -1;
}
return 0;
}
static int __ftrace_make_nop_kernel(struct dyn_ftrace *rec, unsigned long addr)
{
unsigned long tramp, ip = rec->ip;
ppc_inst_t op;
/* Read where this goes */
if (copy_inst_from_kernel_nofault(&op, (void *)ip)) {
pr_err("Fetching opcode failed.\n");
return -EFAULT;
}
/* Make sure that this is still a 24bit jump */
if (!is_bl_op(op)) {
pr_err("Not expected bl: opcode is %08lx\n", ppc_inst_as_ulong(op));
return -EINVAL;
}
/* Let's find where the pointer goes */
tramp = find_bl_target(ip, op);
pr_devel("ip:%lx jumps to %lx", ip, tramp);
if (setup_mcount_compiler_tramp(tramp)) {
/* Are other trampolines reachable? */
if (!find_ftrace_tramp(ip)) {
pr_err("No ftrace trampolines reachable from %ps\n",
(void *)ip);
return -EINVAL;
}
}
if (patch_instruction((u32 *)ip, ppc_inst(PPC_RAW_NOP()))) {
pr_err("Patching NOP failed.\n");
return -EPERM;
}
return 0;
}
int ftrace_make_nop(struct module *mod,
struct dyn_ftrace *rec, unsigned long addr)
{
unsigned long ip = rec->ip;
ppc_inst_t old, new;
/*
* If the calling address is more that 24 bits away,
* then we had to use a trampoline to make the call.
* Otherwise just update the call site.
*/
if (test_24bit_addr(ip, addr)) {
/* within range */
old = ftrace_call_replace(ip, addr, 1);
new = ppc_inst(PPC_RAW_NOP());
return ftrace_modify_code(ip, old, new);
} else if (core_kernel_text(ip)) {
return __ftrace_make_nop_kernel(rec, addr);
} else if (!IS_ENABLED(CONFIG_MODULES)) {
return -EINVAL;
}
/*
* Out of range jumps are called from modules.
* We should either already have a pointer to the module
* or it has been passed in.
*/
if (!rec->arch.mod) {
if (!mod) {
pr_err("No module loaded addr=%lx\n", addr);
return -EFAULT;
}
rec->arch.mod = mod;
} else if (mod) {
if (mod != rec->arch.mod) {
pr_err("Record mod %p not equal to passed in mod %p\n",
rec->arch.mod, mod);
return -EINVAL;
}
/* nothing to do if mod == rec->arch.mod */
} else
mod = rec->arch.mod;
return __ftrace_make_nop(mod, rec, addr);
}
#ifdef CONFIG_MODULES
/*
* Examine the existing instructions for __ftrace_make_call.
* They should effectively be a NOP, and follow formal constraints,
* depending on the ABI. Return false if they don't.
*/
static bool expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
{
if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS))
return ppc_inst_equal(op0, ppc_inst(PPC_RAW_NOP()));
else
return ppc_inst_equal(op0, ppc_inst(PPC_RAW_BRANCH(8))) &&
ppc_inst_equal(op1, ppc_inst(PPC_INST_LD_TOC));
}
static int
__ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
{
ppc_inst_t op[2];
void *ip = (void *)rec->ip;
unsigned long entry, ptr, tramp;
struct module *mod = rec->arch.mod;
/* read where this goes */
if (copy_inst_from_kernel_nofault(op, ip))
return -EFAULT;
if (!IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) &&
copy_inst_from_kernel_nofault(op + 1, ip + 4))
return -EFAULT;
if (!expected_nop_sequence(ip, op[0], op[1])) {
pr_err("Unexpected call sequence at %p: %08lx %08lx\n", ip,
ppc_inst_as_ulong(op[0]), ppc_inst_as_ulong(op[1]));
return -EINVAL;
}
/* If we never set up ftrace trampoline(s), then bail */
if (!mod->arch.tramp ||
(IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) && !mod->arch.tramp_regs)) {
pr_err("No ftrace trampoline\n");
return -EINVAL;
}
if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) && rec->flags & FTRACE_FL_REGS)
tramp = mod->arch.tramp_regs;
else
tramp = mod->arch.tramp;
if (module_trampoline_target(mod, tramp, &ptr)) {
pr_err("Failed to get trampoline target\n");
return -EFAULT;
}
pr_devel("trampoline target %lx", ptr);
entry = ppc_global_function_entry((void *)addr);
/* This should match what was called */
if (ptr != entry) {
pr_err("addr %lx does not match expected %lx\n", ptr, entry);
return -EINVAL;
}
if (patch_branch(ip, tramp, BRANCH_SET_LINK)) {
pr_err("REL24 out of range!\n");
return -EINVAL;
}
return 0;
}
#else
static int __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
{
return 0;
}
#endif /* CONFIG_MODULES */
static int __ftrace_make_call_kernel(struct dyn_ftrace *rec, unsigned long addr)
{
ppc_inst_t op;
void *ip = (void *)rec->ip;
unsigned long tramp, entry, ptr;
/* Make sure we're being asked to patch branch to a known ftrace addr */
entry = ppc_global_function_entry((void *)ftrace_caller);
ptr = ppc_global_function_entry((void *)addr);
if (ptr != entry && IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS))
entry = ppc_global_function_entry((void *)ftrace_regs_caller);
if (ptr != entry) {
pr_err("Unknown ftrace addr to patch: %ps\n", (void *)ptr);
return -EINVAL;
}
/* Make sure we have a nop */
if (copy_inst_from_kernel_nofault(&op, ip)) {
pr_err("Unable to read ftrace location %p\n", ip);
return -EFAULT;
}
if (!ppc_inst_equal(op, ppc_inst(PPC_RAW_NOP()))) {
pr_err("Unexpected call sequence at %p: %08lx\n",
ip, ppc_inst_as_ulong(op));
return -EINVAL;
}
tramp = find_ftrace_tramp((unsigned long)ip);
if (!tramp) {
pr_err("No ftrace trampolines reachable from %ps\n", ip);
return -EINVAL;
}
if (patch_branch(ip, tramp, BRANCH_SET_LINK)) {
pr_err("Error patching branch to ftrace tramp!\n");
return -EINVAL;
}
return 0;
}
int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
{
unsigned long ip = rec->ip;
ppc_inst_t old, new;
/*
* If the calling address is more that 24 bits away,
* then we had to use a trampoline to make the call.
* Otherwise just update the call site.
*/
if (test_24bit_addr(ip, addr)) {
/* within range */
old = ppc_inst(PPC_RAW_NOP());
new = ftrace_call_replace(ip, addr, 1);
return ftrace_modify_code(ip, old, new);
} else if (core_kernel_text(ip)) {
return __ftrace_make_call_kernel(rec, addr);
} else if (!IS_ENABLED(CONFIG_MODULES)) {
/* We should not get here without modules */
return -EINVAL;
}
/*
* Out of range jumps are called from modules.
* Being that we are converting from nop, it had better
* already have a module defined.
*/
if (!rec->arch.mod) {
pr_err("No module loaded\n");
return -EINVAL;
}
return __ftrace_make_call(rec, addr);
}
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
#ifdef CONFIG_MODULES
static int
__ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
unsigned long addr)
{
ppc_inst_t op;
unsigned long ip = rec->ip;
unsigned long entry, ptr, tramp;
struct module *mod = rec->arch.mod;
/* If we never set up ftrace trampolines, then bail */
if (!mod->arch.tramp || !mod->arch.tramp_regs) {
pr_err("No ftrace trampoline\n");
return -EINVAL;
}
/* read where this goes */
if (copy_inst_from_kernel_nofault(&op, (void *)ip)) {
pr_err("Fetching opcode failed.\n");
return -EFAULT;
}
/* Make sure that this is still a 24bit jump */
if (!is_bl_op(op)) {
pr_err("Not expected bl: opcode is %08lx\n", ppc_inst_as_ulong(op));
return -EINVAL;
}
/* lets find where the pointer goes */
tramp = find_bl_target(ip, op);
entry = ppc_global_function_entry((void *)old_addr);
pr_devel("ip:%lx jumps to %lx", ip, tramp);
if (tramp != entry) {
/* old_addr is not within range, so we must have used a trampoline */
if (module_trampoline_target(mod, tramp, &ptr)) {
pr_err("Failed to get trampoline target\n");
return -EFAULT;
}
pr_devel("trampoline target %lx", ptr);
/* This should match what was called */
if (ptr != entry) {
pr_err("addr %lx does not match expected %lx\n", ptr, entry);
return -EINVAL;
}
}
/* The new target may be within range */
if (test_24bit_addr(ip, addr)) {
/* within range */
if (patch_branch((u32 *)ip, addr, BRANCH_SET_LINK)) {
pr_err("REL24 out of range!\n");
return -EINVAL;
}
return 0;
}
if (rec->flags & FTRACE_FL_REGS)
tramp = mod->arch.tramp_regs;
else
tramp = mod->arch.tramp;
if (module_trampoline_target(mod, tramp, &ptr)) {
pr_err("Failed to get trampoline target\n");
return -EFAULT;
}
pr_devel("trampoline target %lx", ptr);
entry = ppc_global_function_entry((void *)addr);
/* This should match what was called */
if (ptr != entry) {
pr_err("addr %lx does not match expected %lx\n", ptr, entry);
return -EINVAL;
}
if (patch_branch((u32 *)ip, tramp, BRANCH_SET_LINK)) {
pr_err("REL24 out of range!\n");
return -EINVAL;
}
return 0;
}
#else
static int __ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, unsigned long addr)
{
return 0;
}
#endif
int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
unsigned long addr)
{
unsigned long ip = rec->ip;
ppc_inst_t old, new;
/*
* If the calling address is more that 24 bits away,
* then we had to use a trampoline to make the call.
* Otherwise just update the call site.
*/
if (test_24bit_addr(ip, addr) && test_24bit_addr(ip, old_addr)) {
/* within range */
old = ftrace_call_replace(ip, old_addr, 1);
new = ftrace_call_replace(ip, addr, 1);
return ftrace_modify_code(ip, old, new);
} else if (core_kernel_text(ip)) {
/*
* We always patch out of range locations to go to the regs
* variant, so there is nothing to do here
*/
return 0;
} else if (!IS_ENABLED(CONFIG_MODULES)) {
/* We should not get here without modules */
return -EINVAL;
}
/*
* Out of range jumps are called from modules.
*/
if (!rec->arch.mod) {
pr_err("No module loaded\n");
return -EINVAL;
}
return __ftrace_modify_call(rec, old_addr, addr);
}
#endif
int ftrace_update_ftrace_func(ftrace_func_t func)
{
unsigned long ip = (unsigned long)(&ftrace_call);
ppc_inst_t old, new;
int ret;
old = ppc_inst_read((u32 *)&ftrace_call);
new = ftrace_call_replace(ip, (unsigned long)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_call_replace(ip, (unsigned long)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);
}
#ifdef CONFIG_PPC64
#define PACATOC offsetof(struct paca_struct, kernel_toc)
extern unsigned int ftrace_tramp_text[], ftrace_tramp_init[];
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;
}
}
int __init ftrace_dyn_arch_init(void)
{
int i;
unsigned int *tramp[] = { ftrace_tramp_text, ftrace_tramp_init };
u32 stub_insns[] = {
PPC_RAW_LD(_R12, _R13, PACATOC),
PPC_RAW_ADDIS(_R12, _R12, 0),
PPC_RAW_ADDI(_R12, _R12, 0),
PPC_RAW_MTCTR(_R12),
PPC_RAW_BCTR()
};
unsigned long addr;
long reladdr;
if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS))
addr = ppc_global_function_entry((void *)ftrace_regs_caller);
else
addr = ppc_global_function_entry((void *)ftrace_caller);
reladdr = addr - kernel_toc_addr();
if (reladdr >= SZ_2G || reladdr < -(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]);
}
return 0;
}
#endif
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
extern void ftrace_graph_call(void);
extern void ftrace_graph_stub(void);
static int ftrace_modify_ftrace_graph_caller(bool enable)
{
unsigned long ip = (unsigned long)(&ftrace_graph_call);
unsigned long addr = (unsigned long)(&ftrace_graph_caller);
unsigned long stub = (unsigned long)(&ftrace_graph_stub);
ppc_inst_t old, new;
if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_ARGS))
return 0;
old = ftrace_call_replace(ip, enable ? stub : addr, 0);
new = ftrace_call_replace(ip, enable ? addr : stub, 0);
return ftrace_modify_code(ip, old, new);
}
int ftrace_enable_ftrace_graph_caller(void)
{
return ftrace_modify_ftrace_graph_caller(true);
}
int ftrace_disable_ftrace_graph_caller(void)
{
return ftrace_modify_ftrace_graph_caller(false);
}
/*
* Hook the return address and push it in the stack of return addrs
* in current thread info. Return the address we want to divert to.
*/
static unsigned long
__prepare_ftrace_return(unsigned long parent, unsigned long ip, unsigned long sp)
{
unsigned long return_hooker;
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);
if (bit < 0)
goto out;
return_hooker = ppc_function_entry(return_to_handler);
if (!function_graph_enter(parent, ip, 0, (unsigned long *)sp))
parent = return_hooker;
ftrace_test_recursion_unlock(bit);
out:
return parent;
}
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS
void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct ftrace_regs *fregs)
{
fregs->regs.link = __prepare_ftrace_return(parent_ip, ip, fregs->regs.gpr[1]);
}
#else
unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip,
unsigned long sp)
{
return __prepare_ftrace_return(parent, ip, sp);
}
#endif
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
#ifdef CONFIG_PPC64_ELF_ABI_V1
char *arch_ftrace_match_adjust(char *str, const char *search)
{
if (str[0] == '.' && search[0] != '.')
return str + 1;
else
return str;
}
#endif /* CONFIG_PPC64_ELF_ABI_V1 */