// SPDX-License-Identifier: GPL-2.0 /* * Code for replacing ftrace calls with jumps. * * Copyright (C) 2007-2008 Steven Rostedt * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef CONFIG_DYNAMIC_FTRACE /* * 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 struct ppc_inst ftrace_call_replace(unsigned long ip, unsigned long addr, int link) { struct ppc_inst op; addr = ppc_function_entry((void *)addr); /* if (link) set op to 'bl' else 'b' */ create_branch(&op, (u32 *)ip, addr, link ? 1 : 0); return op; } static int ftrace_modify_code(unsigned long ip, struct ppc_inst old, struct ppc_inst new) { struct ppc_inst 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 (%s) != old (%s)", (void *)ip, ppc_inst_as_str(replaced), ppc_inst_as_str(old)); return -EINVAL; } /* replace the text with the new text */ if (patch_instruction((u32 *)ip, new)) return -EPERM; return 0; } /* * Helper functions that are the same for both PPC64 and PPC32. */ static int test_24bit_addr(unsigned long ip, unsigned long addr) { struct ppc_inst op; addr = ppc_function_entry((void *)addr); /* use the create_branch to verify that this offset can be branched */ return create_branch(&op, (u32 *)ip, addr, 0) == 0; } static int is_bl_op(struct ppc_inst op) { return (ppc_inst_val(op) & 0xfc000003) == 0x48000001; } static int is_b_op(struct ppc_inst op) { return (ppc_inst_val(op) & 0xfc000003) == 0x48000000; } static unsigned long find_bl_target(unsigned long ip, struct ppc_inst op) { int offset; offset = (ppc_inst_val(op) & 0x03fffffc); /* make it signed */ if (offset & 0x02000000) offset |= 0xfe000000; return ip + (long)offset; } #ifdef CONFIG_MODULES #ifdef CONFIG_PPC64 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; struct ppc_inst 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 that this is still a 24bit jump */ if (!is_bl_op(op)) { pr_err("Not expected bl: opcode is %s\n", ppc_inst_as_str(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; } #ifdef CONFIG_MPROFILE_KERNEL /* When using -mkernel_profile there is no load to jump over */ pop = ppc_inst(PPC_RAW_NOP()); 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 %s around bl _mcount\n", ppc_inst_as_str(op)); return -EINVAL; } #else /* * Our original call site looks like: * * bl * 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. */ pop = ppc_inst(PPC_INST_BRANCH | 8); /* b +8 */ /* * 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 %s\n", PPC_INST_LD_TOC, ppc_inst_as_str(op)); return -EINVAL; } #endif /* CONFIG_MPROFILE_KERNEL */ if (patch_instruction((u32 *)ip, pop)) { pr_err("Patching NOP failed.\n"); return -EPERM; } return 0; } #else /* !PPC64 */ static int __ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr) { struct ppc_inst op; unsigned int jmp[4]; unsigned long ip = rec->ip; unsigned long tramp; if (copy_from_kernel_nofault(&op, (void *)ip, MCOUNT_INSN_SIZE)) return -EFAULT; /* Make sure that that this is still a 24bit jump */ if (!is_bl_op(op)) { pr_err("Not expected bl: opcode is %s\n", ppc_inst_as_str(op)); return -EINVAL; } /* lets find where the pointer goes */ tramp = find_bl_target(ip, op); /* * On PPC32 the trampoline looks like: * 0x3d, 0x80, 0x00, 0x00 lis r12,sym@ha * 0x39, 0x8c, 0x00, 0x00 addi r12,r12,sym@l * 0x7d, 0x89, 0x03, 0xa6 mtctr r12 * 0x4e, 0x80, 0x04, 0x20 bctr */ pr_devel("ip:%lx jumps to %lx", ip, tramp); /* Find where the trampoline jumps to */ if (copy_from_kernel_nofault(jmp, (void *)tramp, sizeof(jmp))) { pr_err("Failed to read %lx\n", tramp); return -EFAULT; } pr_devel(" %08x %08x ", jmp[0], jmp[1]); /* verify that this is what we expect it to be */ if (((jmp[0] & 0xffff0000) != 0x3d800000) || ((jmp[1] & 0xffff0000) != 0x398c0000) || (jmp[2] != 0x7d8903a6) || (jmp[3] != 0x4e800420)) { pr_err("Not a trampoline\n"); return -EINVAL; } tramp = (jmp[1] & 0xffff) | ((jmp[0] & 0xffff) << 16); if (tramp & 0x8000) tramp -= 0x10000; pr_devel(" %lx ", tramp); if (tramp != addr) { pr_err("Trampoline location %08lx does not match addr\n", tramp); return -EINVAL; } op = ppc_inst(PPC_RAW_NOP()); if (patch_instruction((u32 *)ip, op)) return -EPERM; return 0; } #endif /* PPC64 */ #endif /* CONFIG_MODULES */ static unsigned long find_ftrace_tramp(unsigned long ip) { int i; struct ppc_inst instr; /* * 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 (create_branch(&instr, (void *)ip, ftrace_tramps[i], 0) == 0) 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; struct ppc_inst op; unsigned long ptr; struct ppc_inst instr; static unsigned long ftrace_plt_tramps[NUM_FTRACE_TRAMPS]; /* Is this a known long jump tramp? */ for (i = 0; i < NUM_FTRACE_TRAMPS; i++) if (ftrace_tramps[i] == tramp) return 0; /* Is this a known plt tramp? */ for (i = 0; i < NUM_FTRACE_TRAMPS; i++) if (!ftrace_plt_tramps[i]) break; else if (ftrace_plt_tramps[i] == tramp) return -1; /* 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 */ #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS ptr = ppc_global_function_entry((void *)ftrace_regs_caller); #else ptr = ppc_global_function_entry((void *)ftrace_caller); #endif if (create_branch(&instr, (void *)tramp, ptr, 0)) { pr_debug("%ps is not reachable from existing mcount tramp\n", (void *)ptr); return -1; } 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; struct ppc_inst 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 that this is still a 24bit jump */ if (!is_bl_op(op)) { pr_err("Not expected bl: opcode is %s\n", ppc_inst_as_str(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; struct ppc_inst 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); #ifdef CONFIG_MODULES /* * 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); #else /* We should not get here without modules */ return -EINVAL; #endif /* CONFIG_MODULES */ } #ifdef CONFIG_MODULES #ifdef CONFIG_PPC64 /* * 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. */ #ifndef CONFIG_MPROFILE_KERNEL static int expected_nop_sequence(void *ip, struct ppc_inst op0, struct ppc_inst op1) { /* * We expect to see: * * b +8 * ld r2,XX(r1) * * The load offset is different depending on the ABI. For simplicity * just mask it out when doing the compare. */ if (!ppc_inst_equal(op0, ppc_inst(0x48000008)) || (ppc_inst_val(op1) & 0xffff0000) != 0xe8410000) return 0; return 1; } #else static int expected_nop_sequence(void *ip, struct ppc_inst op0, struct ppc_inst op1) { /* look for patched "NOP" on ppc64 with -mprofile-kernel */ if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_NOP()))) return 0; return 1; } #endif static int __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) { struct ppc_inst op[2]; struct ppc_inst instr; 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 (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: %s %s\n", ip, ppc_inst_as_str(op[0]), ppc_inst_as_str(op[1])); return -EINVAL; } /* If we never set up ftrace trampoline(s), then bail */ #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS if (!mod->arch.tramp || !mod->arch.tramp_regs) { #else if (!mod->arch.tramp) { #endif pr_err("No ftrace trampoline\n"); return -EINVAL; } #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS if (rec->flags & FTRACE_FL_REGS) tramp = mod->arch.tramp_regs; else #endif 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; } /* Ensure branch is within 24 bits */ if (create_branch(&instr, ip, tramp, BRANCH_SET_LINK)) { pr_err("Branch out of range\n"); return -EINVAL; } if (patch_branch(ip, tramp, BRANCH_SET_LINK)) { pr_err("REL24 out of range!\n"); return -EINVAL; } return 0; } #else /* !CONFIG_PPC64: */ static int __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) { int err; struct ppc_inst op; u32 *ip = (u32 *)rec->ip; /* read where this goes */ if (copy_inst_from_kernel_nofault(&op, ip)) return -EFAULT; /* It should be pointing to a nop */ if (!ppc_inst_equal(op, ppc_inst(PPC_RAW_NOP()))) { pr_err("Expected NOP but have %s\n", ppc_inst_as_str(op)); return -EINVAL; } /* If we never set up a trampoline to ftrace_caller, then bail */ if (!rec->arch.mod->arch.tramp) { pr_err("No ftrace trampoline\n"); return -EINVAL; } /* create the branch to the trampoline */ err = create_branch(&op, ip, rec->arch.mod->arch.tramp, BRANCH_SET_LINK); if (err) { pr_err("REL24 out of range!\n"); return -EINVAL; } pr_devel("write to %lx\n", rec->ip); if (patch_instruction(ip, op)) return -EPERM; return 0; } #endif /* CONFIG_PPC64 */ #endif /* CONFIG_MODULES */ static int __ftrace_make_call_kernel(struct dyn_ftrace *rec, unsigned long addr) { struct ppc_inst 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) { #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS entry = ppc_global_function_entry((void *)ftrace_regs_caller); if (ptr != entry) { #endif pr_err("Unknown ftrace addr to patch: %ps\n", (void *)ptr); return -EINVAL; #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS } #endif } /* 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: %s\n", ip, ppc_inst_as_str(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; struct ppc_inst 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); #ifdef CONFIG_MODULES /* * 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); #else /* We should not get here without modules */ return -EINVAL; #endif /* CONFIG_MODULES */ } #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) { struct ppc_inst 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 that this is still a 24bit jump */ if (!is_bl_op(op)) { pr_err("Not expected bl: opcode is %s\n", ppc_inst_as_str(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; } /* Ensure branch is within 24 bits */ if (create_branch(&op, (u32 *)ip, tramp, BRANCH_SET_LINK)) { pr_err("Branch out of range\n"); return -EINVAL; } if (patch_branch((u32 *)ip, tramp, BRANCH_SET_LINK)) { pr_err("REL24 out of range!\n"); return -EINVAL; } return 0; } #endif int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, unsigned long addr) { unsigned long ip = rec->ip; struct ppc_inst 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; } #ifdef CONFIG_MODULES /* * 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); #else /* We should not get here without modules */ return -EINVAL; #endif /* CONFIG_MODULES */ } #endif int ftrace_update_ftrace_func(ftrace_func_t func) { unsigned long ip = (unsigned long)(&ftrace_call); struct ppc_inst 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); #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS /* Also update the regs callback function */ if (!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); } #endif 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[] = { 0xe98d0000 | PACATOC, /* ld r12,PACATOC(r13) */ 0x3d8c0000, /* addis r12,r12, */ 0x398c0000, /* addi r12,r12, */ 0x7d8903a6, /* mtctr r12 */ 0x4e800420, /* bctr */ }; #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS unsigned long addr = ppc_global_function_entry((void *)ftrace_regs_caller); #else unsigned long addr = ppc_global_function_entry((void *)ftrace_caller); #endif long reladdr = addr - kernel_toc_addr(); if (reladdr > 0x7FFFFFFF || reladdr < -(0x80000000L)) { 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; } #else int __init ftrace_dyn_arch_init(void) { return 0; } #endif #endif /* CONFIG_DYNAMIC_FTRACE */ #ifdef CONFIG_FUNCTION_GRAPH_TRACER extern void ftrace_graph_call(void); extern void ftrace_graph_stub(void); int ftrace_enable_ftrace_graph_caller(void) { unsigned long ip = (unsigned long)(&ftrace_graph_call); unsigned long addr = (unsigned long)(&ftrace_graph_caller); unsigned long stub = (unsigned long)(&ftrace_graph_stub); struct ppc_inst old, new; old = ftrace_call_replace(ip, stub, 0); new = ftrace_call_replace(ip, addr, 0); return ftrace_modify_code(ip, old, new); } int ftrace_disable_ftrace_graph_caller(void) { unsigned long ip = (unsigned long)(&ftrace_graph_call); unsigned long addr = (unsigned long)(&ftrace_graph_caller); unsigned long stub = (unsigned long)(&ftrace_graph_stub); struct ppc_inst old, new; old = ftrace_call_replace(ip, addr, 0); new = ftrace_call_replace(ip, stub, 0); return ftrace_modify_code(ip, old, new); } /* * 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. */ unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip, unsigned long sp) { unsigned long return_hooker; if (unlikely(ftrace_graph_is_dead())) goto out; if (unlikely(atomic_read(¤t->tracing_graph_pause))) goto out; return_hooker = ppc_function_entry(return_to_handler); if (!function_graph_enter(parent, ip, 0, (unsigned long *)sp)) parent = return_hooker; out: return parent; } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ #ifdef 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 /* PPC64_ELF_ABI_v1 */