diff options
Diffstat (limited to 'arch/powerpc/kernel/trace')
| -rw-r--r-- | arch/powerpc/kernel/trace/Makefile | 21 | ||||
| -rw-r--r-- | arch/powerpc/kernel/trace/ftrace.c | 1211 | ||||
| -rw-r--r-- | arch/powerpc/kernel/trace/ftrace_32.S | 95 | ||||
| -rw-r--r-- | arch/powerpc/kernel/trace/ftrace_64.S | 64 | ||||
| -rw-r--r-- | arch/powerpc/kernel/trace/ftrace_64_mprofile.S | 330 | ||||
| -rw-r--r-- | arch/powerpc/kernel/trace/ftrace_64_pg.c | 832 | ||||
| -rw-r--r-- | arch/powerpc/kernel/trace/ftrace_64_pg_entry.S (renamed from arch/powerpc/kernel/trace/ftrace_64_pg.S) | 67 | ||||
| -rw-r--r-- | arch/powerpc/kernel/trace/ftrace_entry.S | 471 |
8 files changed, 1836 insertions, 1255 deletions
diff --git a/arch/powerpc/kernel/trace/Makefile b/arch/powerpc/kernel/trace/Makefile index 858503775c58..d6c3885453bd 100644 --- a/arch/powerpc/kernel/trace/Makefile +++ b/arch/powerpc/kernel/trace/Makefile @@ -6,18 +6,18 @@ ifdef CONFIG_FUNCTION_TRACER # do not trace tracer code CFLAGS_REMOVE_ftrace.o = $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_ftrace_64_pg.o = $(CC_FLAGS_FTRACE) endif -obj32-$(CONFIG_FUNCTION_TRACER) += ftrace_32.o -obj64-$(CONFIG_FUNCTION_TRACER) += ftrace_64.o -ifdef CONFIG_MPROFILE_KERNEL -obj64-$(CONFIG_FUNCTION_TRACER) += ftrace_64_mprofile.o +ifdef CONFIG_FUNCTION_TRACER +obj32-y += ftrace.o ftrace_entry.o +ifeq ($(CONFIG_MPROFILE_KERNEL)$(CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY),) +obj64-y += ftrace_64_pg.o ftrace_64_pg_entry.o else -obj64-$(CONFIG_FUNCTION_TRACER) += ftrace_64_pg.o +obj64-y += ftrace.o ftrace_entry.o +endif endif -obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o -obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o -obj-$(CONFIG_FTRACE_SYSCALLS) += ftrace.o + obj-$(CONFIG_TRACING) += trace_clock.o obj-$(CONFIG_PPC64) += $(obj64-y) @@ -26,4 +26,9 @@ obj-$(CONFIG_PPC32) += $(obj32-y) # Disable GCOV, KCOV & sanitizers in odd or sensitive code GCOV_PROFILE_ftrace.o := n KCOV_INSTRUMENT_ftrace.o := n +KCSAN_SANITIZE_ftrace.o := n UBSAN_SANITIZE_ftrace.o := n +GCOV_PROFILE_ftrace_64_pg.o := n +KCOV_INSTRUMENT_ftrace_64_pg.o := n +KCSAN_SANITIZE_ftrace_64_pg.o := n +UBSAN_SANITIZE_ftrace_64_pg.o := n diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c index 7ea0ca044b65..6dca92d5a6e8 100644 --- a/arch/powerpc/kernel/trace/ftrace.c +++ b/arch/powerpc/kernel/trace/ftrace.c @@ -22,834 +22,531 @@ #include <linux/init.h> #include <linux/list.h> -#include <asm/asm-prototypes.h> #include <asm/cacheflush.h> -#include <asm/code-patching.h> +#include <asm/text-patching.h> #include <asm/ftrace.h> #include <asm/syscall.h> +#include <asm/inst.h> +#include <asm/sections.h> - -#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 +#define NUM_FTRACE_TRAMPS 2 static unsigned long ftrace_tramps[NUM_FTRACE_TRAMPS]; -static unsigned int -ftrace_call_replace(unsigned long ip, unsigned long addr, int link) -{ - unsigned int op; - - addr = ppc_function_entry((void *)addr); - - /* if (link) set op to 'bl' else 'b' */ - op = create_branch((unsigned int *)ip, addr, link ? 1 : 0); - - return op; -} - -static int -ftrace_modify_code(unsigned long ip, unsigned int old, unsigned int new) +unsigned long ftrace_call_adjust(unsigned long addr) { - unsigned int 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 (probe_kernel_read(&replaced, (void *)ip, MCOUNT_INSN_SIZE)) - return -EFAULT; + if (addr >= (unsigned long)__exittext_begin && addr < (unsigned long)__exittext_end) + return 0; - /* Make sure it is what we expect it to be */ - if (replaced != old) { - pr_err("%p: replaced (%#x) != old (%#x)", - (void *)ip, replaced, old); - return -EINVAL; + if (IS_ENABLED(CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY) && + !IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE)) { + addr += MCOUNT_INSN_SIZE; + if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS)) + addr += MCOUNT_INSN_SIZE; } - /* replace the text with the new text */ - if (patch_instruction((unsigned int *)ip, new)) - return -EPERM; - - return 0; + return addr; } -/* - * Helper functions that are the same for both PPC64 and PPC32. - */ -static int test_24bit_addr(unsigned long ip, unsigned long addr) +static ppc_inst_t ftrace_create_branch_inst(unsigned long ip, unsigned long addr, int link) { - addr = ppc_function_entry((void *)addr); + ppc_inst_t op; - /* use the create_branch to verify that this offset can be branched */ - return create_branch((unsigned int *)ip, addr, 0); -} + WARN_ON(!is_offset_in_branch_range(addr - ip)); + create_branch(&op, (u32 *)ip, addr, link ? BRANCH_SET_LINK : 0); -static int is_bl_op(unsigned int op) -{ - return (op & 0xfc000003) == 0x48000001; -} - -static int is_b_op(unsigned int op) -{ - return (op & 0xfc000003) == 0x48000000; -} - -static unsigned long find_bl_target(unsigned long ip, unsigned int op) -{ - int offset; - - offset = (op & 0x03fffffc); - /* make it signed */ - if (offset & 0x02000000) - offset |= 0xfe000000; - - return ip + (long)offset; + return op; } -#ifdef CONFIG_MODULES -#ifdef CONFIG_PPC64 -static int -__ftrace_make_nop(struct module *mod, - struct dyn_ftrace *rec, unsigned long addr) +static inline int ftrace_read_inst(unsigned long ip, ppc_inst_t *op) { - unsigned long entry, ptr, tramp; - unsigned long ip = rec->ip; - unsigned int op, pop; - - /* read where this goes */ - if (probe_kernel_read(&op, (void *)ip, sizeof(int))) { - pr_err("Fetching opcode failed.\n"); + if (copy_inst_from_kernel_nofault(op, (void *)ip)) { + pr_err("0x%lx: fetching instruction failed\n", ip); return -EFAULT; } - /* Make sure that that this is still a 24bit jump */ - if (!is_bl_op(op)) { - pr_err("Not expected bl: opcode is %x\n", 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_NOP; - - if (probe_kernel_read(&op, (void *)(ip - 4), 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 (op != PPC_INST_MFLR && op != PPC_INST_STD_LR) { - pr_err("Unexpected instruction %08x around bl _mcount\n", op); - return -EINVAL; - } -#else - /* - * 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. - */ - - pop = 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 (probe_kernel_read(&op, (void *)(ip+4), MCOUNT_INSN_SIZE)) { - pr_err("Fetching op failed.\n"); - return -EFAULT; - } - - if (op != PPC_INST_LD_TOC) { - pr_err("Expected %08x found %08x\n", PPC_INST_LD_TOC, op); - return -EINVAL; - } -#endif /* CONFIG_MPROFILE_KERNEL */ - - if (patch_instruction((unsigned int *)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) +static inline int ftrace_validate_inst(unsigned long ip, ppc_inst_t inst) { - unsigned int op; - unsigned int jmp[4]; - unsigned long ip = rec->ip; - unsigned long tramp; - - if (probe_kernel_read(&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 %x\n", 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 (probe_kernel_read(jmp, (void *)tramp, sizeof(jmp))) { - pr_err("Failed to read %lx\n", tramp); - return -EFAULT; - } - - pr_devel(" %08x %08x ", jmp[0], jmp[1]); + ppc_inst_t op; + int ret; - /* 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; + ret = ftrace_read_inst(ip, &op); + if (!ret && !ppc_inst_equal(op, inst)) { + pr_err("0x%lx: expected (%08lx) != found (%08lx)\n", + ip, ppc_inst_as_ulong(inst), ppc_inst_as_ulong(op)); + ret = -EINVAL; } - tramp = (jmp[1] & 0xffff) | - ((jmp[0] & 0xffff) << 16); - if (tramp & 0x8000) - tramp -= 0x10000; - - pr_devel(" %lx ", tramp); + return ret; +} - if (tramp != addr) { - pr_err("Trampoline location %08lx does not match addr\n", - tramp); - return -EINVAL; - } +static inline int ftrace_modify_code(unsigned long ip, ppc_inst_t old, ppc_inst_t new) +{ + int ret = ftrace_validate_inst(ip, old); - op = PPC_INST_NOP; + if (!ret && !ppc_inst_equal(old, new)) + ret = patch_instruction((u32 *)ip, new); - if (patch_instruction((unsigned int *)ip, op)) - return -EPERM; + return ret; +} - return 0; +static int is_bl_op(ppc_inst_t op) +{ + return (ppc_inst_val(op) & ~PPC_LI_MASK) == PPC_RAW_BL(0); } -#endif /* PPC64 */ -#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--) + for (i = 0; i < NUM_FTRACE_TRAMPS; i++) if (!ftrace_tramps[i]) continue; - else if (create_branch((void *)ip, ftrace_tramps[i], 0)) + 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) +#ifdef CONFIG_MODULES +static unsigned long ftrace_lookup_module_stub(unsigned long ip, unsigned long addr) { - int i; + struct module *mod = NULL; - for (i = 0; i < NUM_FTRACE_TRAMPS; i++) - if (!ftrace_tramps[i]) { - ftrace_tramps[i] = tramp; - return 0; - } + scoped_guard(rcu) + mod = __module_text_address(ip); + if (!mod) + pr_err("No module loaded at addr=%lx\n", ip); - return -1; + return (addr == (unsigned long)ftrace_caller ? mod->arch.tramp : mod->arch.tramp_regs); } - -/* - * 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) +#else +static unsigned long ftrace_lookup_module_stub(unsigned long ip, unsigned long addr) { - int i, op; - unsigned long ptr; - 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]) - break; - else 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 (probe_kernel_read(&op, (void *)tramp, sizeof(int))) { - 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; - } + return 0; +} +#endif - /* 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); +static unsigned long ftrace_get_ool_stub(struct dyn_ftrace *rec) +{ +#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE + return rec->arch.ool_stub; #else - ptr = ppc_global_function_entry((void *)ftrace_caller); + BUILD_BUG(); #endif - if (!create_branch((void *)tramp, ptr, 0)) { - pr_debug("%ps is not reachable from existing mcount tramp\n", - (void *)ptr); - return -1; - } - - if (patch_branch((unsigned int *)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) +static int ftrace_get_call_inst(struct dyn_ftrace *rec, unsigned long addr, ppc_inst_t *call_inst) { - unsigned long tramp, ip = rec->ip; - unsigned int op; + unsigned long ip; + unsigned long stub; - /* Read where this goes */ - if (probe_kernel_read(&op, (void *)ip, sizeof(int))) { - 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 %x\n", 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); + if (IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE)) + ip = ftrace_get_ool_stub(rec) + MCOUNT_INSN_SIZE; /* second instruction in stub */ + else + ip = rec->ip; + + if (!is_offset_in_branch_range(addr - ip) && addr != FTRACE_ADDR && + addr != FTRACE_REGS_ADDR) { + /* This can only happen with ftrace direct */ + if (!IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS)) { + pr_err("0x%lx (0x%lx): Unexpected target address 0x%lx\n", + ip, rec->ip, addr); return -EINVAL; } + addr = FTRACE_ADDR; } - if (patch_instruction((unsigned int *)ip, PPC_INST_NOP)) { - pr_err("Patching NOP failed.\n"); - return -EPERM; + if (is_offset_in_branch_range(addr - ip)) + /* Within range */ + stub = addr; + else if (core_kernel_text(ip)) + /* We would be branching to one of our ftrace stubs */ + stub = find_ftrace_tramp(ip); + else + stub = ftrace_lookup_module_stub(ip, addr); + + if (!stub) { + pr_err("0x%lx (0x%lx): No ftrace stubs reachable\n", ip, rec->ip); + return -EINVAL; } + *call_inst = ftrace_create_branch_inst(ip, stub, 1); return 0; } -int ftrace_make_nop(struct module *mod, - struct dyn_ftrace *rec, unsigned long addr) +static int ftrace_init_ool_stub(struct module *mod, struct dyn_ftrace *rec) { - unsigned long ip = rec->ip; - unsigned int old, new; - +#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE + static int ool_stub_text_index, ool_stub_text_end_index, ool_stub_inittext_index; + int ret = 0, ool_stub_count, *ool_stub_index; + ppc_inst_t inst; /* - * 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. + * See ftrace_entry.S if changing the below instruction sequence, as we rely on + * decoding the last branch instruction here to recover the correct function ip. */ - if (test_24bit_addr(ip, addr)) { - /* within range */ - old = ftrace_call_replace(ip, addr, 1); - new = PPC_INST_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; + struct ftrace_ool_stub *ool_stub, ool_stub_template = { + .insn = { + PPC_RAW_MFLR(_R0), + PPC_RAW_NOP(), /* bl ftrace_caller */ + PPC_RAW_MTLR(_R0), + PPC_RAW_NOP() /* b rec->ip + 4 */ } - /* 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 */ -} + WARN_ON(rec->arch.ool_stub); + if (is_kernel_inittext(rec->ip)) { + ool_stub = ftrace_ool_stub_inittext; + ool_stub_index = &ool_stub_inittext_index; + ool_stub_count = ftrace_ool_stub_inittext_count; + } else if (is_kernel_text(rec->ip)) { + /* + * ftrace records are sorted, so we first use up the stub area within .text + * (ftrace_ool_stub_text) before using the area at the end of .text + * (ftrace_ool_stub_text_end), unless the stub is out of range of the record. + */ + if (ool_stub_text_index >= ftrace_ool_stub_text_count || + !is_offset_in_branch_range((long)rec->ip - + (long)&ftrace_ool_stub_text[ool_stub_text_index])) { + ool_stub = ftrace_ool_stub_text_end; + ool_stub_index = &ool_stub_text_end_index; + ool_stub_count = ftrace_ool_stub_text_end_count; + } else { + ool_stub = ftrace_ool_stub_text; + ool_stub_index = &ool_stub_text_index; + ool_stub_count = ftrace_ool_stub_text_count; + } #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, unsigned int op0, unsigned int 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 ((op0 != 0x48000008) || ((op1 & 0xffff0000) != 0xe8410000)) - return 0; - return 1; -} -#else -static int -expected_nop_sequence(void *ip, unsigned int op0, unsigned int op1) -{ - /* look for patched "NOP" on ppc64 with -mprofile-kernel */ - if (op0 != PPC_INST_NOP) - return 0; - return 1; -} + } else if (mod) { + ool_stub = mod->arch.ool_stubs; + ool_stub_index = &mod->arch.ool_stub_index; + ool_stub_count = mod->arch.ool_stub_count; #endif + } else { + return -EINVAL; + } -static int -__ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) -{ - unsigned int op[2]; - void *ip = (void *)rec->ip; - unsigned long entry, ptr, tramp; - struct module *mod = rec->arch.mod; - - /* read where this goes */ - if (probe_kernel_read(op, ip, sizeof(op))) - return -EFAULT; + ool_stub += (*ool_stub_index)++; - if (!expected_nop_sequence(ip, op[0], op[1])) { - pr_err("Unexpected call sequence at %p: %x %x\n", - ip, op[0], op[1]); + if (WARN_ON(*ool_stub_index > ool_stub_count)) 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"); + if (!is_offset_in_branch_range((long)rec->ip - (long)&ool_stub->insn[0]) || + !is_offset_in_branch_range((long)(rec->ip + MCOUNT_INSN_SIZE) - + (long)&ool_stub->insn[3])) { + pr_err("%s: ftrace ool stub out of range (%p -> %p).\n", + __func__, (void *)rec->ip, (void *)&ool_stub->insn[0]); return -EINVAL; } -#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS - if (rec->flags & FTRACE_FL_REGS) - tramp = mod->arch.tramp_regs; + rec->arch.ool_stub = (unsigned long)&ool_stub->insn[0]; + + /* bl ftrace_caller */ + if (!mod) + ret = ftrace_get_call_inst(rec, (unsigned long)ftrace_caller, &inst); +#ifdef CONFIG_MODULES else + /* + * We can't use ftrace_get_call_inst() since that uses + * __module_text_address(rec->ip) to look up the module. + * But, since the module is not fully formed at this stage, + * the lookup fails. We know the target though, so generate + * the branch inst directly. + */ + inst = ftrace_create_branch_inst(ftrace_get_ool_stub(rec) + MCOUNT_INSN_SIZE, + mod->arch.tramp, 1); #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; - } + ool_stub_template.insn[1] = ppc_inst_val(inst); - /* Ensure branch is within 24 bits */ - if (!create_branch(ip, tramp, BRANCH_SET_LINK)) { - pr_err("Branch out of range\n"); + /* b rec->ip + 4 */ + if (!ret && create_branch(&inst, &ool_stub->insn[3], rec->ip + MCOUNT_INSN_SIZE, 0)) return -EINVAL; - } + ool_stub_template.insn[3] = ppc_inst_val(inst); - if (patch_branch(ip, tramp, BRANCH_SET_LINK)) { - pr_err("REL24 out of range!\n"); - return -EINVAL; - } + if (!ret) + ret = patch_instructions((u32 *)ool_stub, (u32 *)&ool_stub_template, + sizeof(ool_stub_template), false); - return 0; + return ret; +#else /* !CONFIG_PPC_FTRACE_OUT_OF_LINE */ + BUILD_BUG(); +#endif } -#else /* !CONFIG_PPC64: */ -static int -__ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS +static const struct ftrace_ops *powerpc_rec_get_ops(struct dyn_ftrace *rec) { - unsigned int op; - unsigned long ip = rec->ip; + const struct ftrace_ops *ops = NULL; - /* read where this goes */ - if (probe_kernel_read(&op, (void *)ip, MCOUNT_INSN_SIZE)) - return -EFAULT; - - /* It should be pointing to a nop */ - if (op != PPC_INST_NOP) { - pr_err("Expected NOP but have %x\n", op); - return -EINVAL; + if (rec->flags & FTRACE_FL_CALL_OPS_EN) { + ops = ftrace_find_unique_ops(rec); + WARN_ON_ONCE(!ops); } - /* 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; - } + if (!ops) + ops = &ftrace_list_ops; - /* create the branch to the trampoline */ - op = create_branch((unsigned int *)ip, - rec->arch.mod->arch.tramp, BRANCH_SET_LINK); - if (!op) { - pr_err("REL24 out of range!\n"); - return -EINVAL; - } - - pr_devel("write to %lx\n", rec->ip); - - if (patch_instruction((unsigned int *)ip, op)) - return -EPERM; - - return 0; + return ops; } -#endif /* CONFIG_PPC64 */ -#endif /* CONFIG_MODULES */ -static int __ftrace_make_call_kernel(struct dyn_ftrace *rec, unsigned long addr) +static int ftrace_rec_set_ops(struct dyn_ftrace *rec, const struct ftrace_ops *ops) { - unsigned int op; - void *ip = (void *)rec->ip; - unsigned long tramp, entry, ptr; + if (IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE)) + return patch_ulong((void *)(ftrace_get_ool_stub(rec) - sizeof(unsigned long)), + (unsigned long)ops); + else + return patch_ulong((void *)(rec->ip - MCOUNT_INSN_SIZE - sizeof(unsigned long)), + (unsigned long)ops); +} - /* 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); +static int ftrace_rec_set_nop_ops(struct dyn_ftrace *rec) +{ + return ftrace_rec_set_ops(rec, &ftrace_nop_ops); +} - if (ptr != entry) { -#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS - entry = ppc_global_function_entry((void *)ftrace_regs_caller); - if (ptr != entry) { +static int ftrace_rec_update_ops(struct dyn_ftrace *rec) +{ + return ftrace_rec_set_ops(rec, powerpc_rec_get_ops(rec)); +} +#else +static int ftrace_rec_set_nop_ops(struct dyn_ftrace *rec) { return 0; } +static int ftrace_rec_update_ops(struct dyn_ftrace *rec) { return 0; } #endif - pr_err("Unknown ftrace addr to patch: %ps\n", (void *)ptr); - return -EINVAL; + #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS - } +int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, unsigned long addr) +{ + /* This should never be called since we override ftrace_replace_code() */ + WARN_ON(1); + return -EINVAL; +} #endif - } - /* Make sure we have a nop */ - if (probe_kernel_read(&op, ip, sizeof(op))) { - pr_err("Unable to read ftrace location %p\n", ip); - return -EFAULT; - } +int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) +{ + ppc_inst_t old, new; + unsigned long ip = rec->ip; + int ret = 0; - if (op != PPC_INST_NOP) { - pr_err("Unexpected call sequence at %p: %x\n", ip, op); + /* This can only ever be called during module load */ + if (WARN_ON(!IS_ENABLED(CONFIG_MODULES) || core_kernel_text(ip))) return -EINVAL; - } - tramp = find_ftrace_tramp((unsigned long)ip); - if (!tramp) { - pr_err("No ftrace trampolines reachable from %ps\n", ip); - return -EINVAL; + old = ppc_inst(PPC_RAW_NOP()); + if (IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE)) { + ip = ftrace_get_ool_stub(rec) + MCOUNT_INSN_SIZE; /* second instruction in stub */ + ret = ftrace_get_call_inst(rec, (unsigned long)ftrace_caller, &old); } - if (patch_branch(ip, tramp, BRANCH_SET_LINK)) { - pr_err("Error patching branch to ftrace tramp!\n"); - return -EINVAL; - } + ret |= ftrace_get_call_inst(rec, addr, &new); - return 0; -} + if (!ret) + ret = ftrace_modify_code(ip, old, new); -int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) -{ - unsigned long ip = rec->ip; - unsigned int old, new; + ret = ftrace_rec_update_ops(rec); + if (ret) + return ret; - /* - * 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_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); + if (!ret && IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE)) + ret = ftrace_modify_code(rec->ip, ppc_inst(PPC_RAW_NOP()), + ppc_inst(PPC_RAW_BRANCH((long)ftrace_get_ool_stub(rec) - (long)rec->ip))); -#ifdef CONFIG_MODULES + return ret; +} + +int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr) +{ /* - * Out of range jumps are called from modules. - * Being that we are converting from nop, it had better - * already have a module defined. + * This should never be called since we override ftrace_replace_code(), + * as well as ftrace_init_nop() */ - 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 */ + WARN_ON(1); 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) +void ftrace_replace_code(int enable) { - unsigned int 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 (probe_kernel_read(&op, (void *)ip, sizeof(int))) { - 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 %x\n", op); - return -EINVAL; - } - - /* lets find where the pointer goes */ - tramp = find_bl_target(ip, op); - entry = ppc_global_function_entry((void *)old_addr); + ppc_inst_t old, new, call_inst, new_call_inst; + ppc_inst_t nop_inst = ppc_inst(PPC_RAW_NOP()); + unsigned long ip, new_addr, addr; + struct ftrace_rec_iter *iter; + struct dyn_ftrace *rec; + int ret = 0, update; + + for_ftrace_rec_iter(iter) { + rec = ftrace_rec_iter_record(iter); + ip = rec->ip; + + if (rec->flags & FTRACE_FL_DISABLED && !(rec->flags & FTRACE_FL_ENABLED)) + continue; - pr_devel("ip:%lx jumps to %lx", ip, tramp); + addr = ftrace_get_addr_curr(rec); + new_addr = ftrace_get_addr_new(rec); + update = ftrace_update_record(rec, enable); - 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; + if (IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE) && update != FTRACE_UPDATE_IGNORE) { + ip = ftrace_get_ool_stub(rec) + MCOUNT_INSN_SIZE; + ret = ftrace_get_call_inst(rec, (unsigned long)ftrace_caller, &nop_inst); + if (ret) + goto out; } - 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((unsigned int *)ip, addr, BRANCH_SET_LINK)) { - pr_err("REL24 out of range!\n"); - return -EINVAL; + switch (update) { + case FTRACE_UPDATE_IGNORE: + default: + continue; + case FTRACE_UPDATE_MODIFY_CALL: + ret = ftrace_get_call_inst(rec, new_addr, &new_call_inst); + ret |= ftrace_get_call_inst(rec, addr, &call_inst); + ret |= ftrace_rec_update_ops(rec); + old = call_inst; + new = new_call_inst; + break; + case FTRACE_UPDATE_MAKE_NOP: + ret = ftrace_get_call_inst(rec, addr, &call_inst); + ret |= ftrace_rec_set_nop_ops(rec); + old = call_inst; + new = nop_inst; + break; + case FTRACE_UPDATE_MAKE_CALL: + ret = ftrace_get_call_inst(rec, new_addr, &call_inst); + ret |= ftrace_rec_update_ops(rec); + old = nop_inst; + new = call_inst; + break; } - 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; - } + if (!ret) + ret = ftrace_modify_code(ip, old, new); - pr_devel("trampoline target %lx", ptr); + if (!ret && IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE) && + (update == FTRACE_UPDATE_MAKE_NOP || update == FTRACE_UPDATE_MAKE_CALL)) { + /* Update the actual ftrace location */ + call_inst = ppc_inst(PPC_RAW_BRANCH((long)ftrace_get_ool_stub(rec) - + (long)rec->ip)); + nop_inst = ppc_inst(PPC_RAW_NOP()); + ip = rec->ip; - 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 (update == FTRACE_UPDATE_MAKE_NOP) + ret = ftrace_modify_code(ip, call_inst, nop_inst); + else + ret = ftrace_modify_code(ip, nop_inst, call_inst); - /* Ensure branch is within 24 bits */ - if (!create_branch((unsigned int *)ip, tramp, BRANCH_SET_LINK)) { - pr_err("Branch out of range\n"); - return -EINVAL; - } + if (ret) + goto out; + } - if (patch_branch((unsigned int *)ip, tramp, BRANCH_SET_LINK)) { - pr_err("REL24 out of range!\n"); - return -EINVAL; + if (ret) + goto out; } - return 0; +out: + if (ret) + ftrace_bug(ret, rec); + return; } -#endif -int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, - unsigned long addr) +int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) { - unsigned long ip = rec->ip; - unsigned int old, new; + unsigned long addr, ip = rec->ip; + ppc_inst_t old, new; + int ret = 0; + + /* Verify instructions surrounding the ftrace location */ + if (IS_ENABLED(CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY)) { + /* Expect nops */ + if (!IS_ENABLED(CONFIG_PPC_FTRACE_OUT_OF_LINE)) + ret = ftrace_validate_inst(ip - 4, ppc_inst(PPC_RAW_NOP())); + if (!ret) + ret = ftrace_validate_inst(ip, ppc_inst(PPC_RAW_NOP())); + } else if (IS_ENABLED(CONFIG_PPC32)) { + /* Expected sequence: 'mflr r0', 'stw r0,4(r1)', 'bl _mcount' */ + 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_STW(_R0, _R1, 4)), + ppc_inst(PPC_RAW_NOP())); + } else if (IS_ENABLED(CONFIG_MPROFILE_KERNEL)) { + /* 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 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)) { + 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 always patch out of range locations to go to the regs - * variant, so there is nothing to do here + * We would be branching to a linker-generated stub, or to the module _mcount + * stub. Let's just confirm we have a 'bl' here. */ - return 0; - } - -#ifdef CONFIG_MODULES - /* - * Out of range jumps are called from modules. - */ - if (!rec->arch.mod) { - pr_err("No module loaded\n"); + 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 __ftrace_modify_call(rec, old_addr, addr); -#else - /* We should not get here without modules */ - return -EINVAL; -#endif /* CONFIG_MODULES */ + return ret; } -#endif int ftrace_update_ftrace_func(ftrace_func_t func) { unsigned long ip = (unsigned long)(&ftrace_call); - unsigned int old, new; + ppc_inst_t old, new; int ret; - old = *(unsigned int *)&ftrace_call; - new = ftrace_call_replace(ip, (unsigned long)func, 1); + /* + * 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); -#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS /* Also update the regs callback function */ - if (!ret) { + if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) && !ret) { ip = (unsigned long)(&ftrace_regs_call); - old = *(unsigned int *)&ftrace_regs_call; - new = ftrace_call_replace(ip, (unsigned long)func, 1); + 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); } -#endif return ret; } @@ -863,91 +560,102 @@ 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[]; - -int __init ftrace_dyn_arch_init(void) +void ftrace_free_init_tramp(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,<high> */ - 0x398c0000, /* addi r12,r12,<low> */ - 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 < NUM_FTRACE_TRAMPS && ftrace_tramps[i]; i++) + if (ftrace_tramps[i] == (unsigned long)ftrace_tramp_init) { + ftrace_tramps[i] = 0; + return; + } +} - 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]); - } +static void __init add_ftrace_tramp(unsigned long tramp) +{ + int i; - return 0; + for (i = 0; i < NUM_FTRACE_TRAMPS; i++) + if (!ftrace_tramps[i]) { + ftrace_tramps[i] = tramp; + return; + } } -#else + int __init ftrace_dyn_arch_init(void) { - return 0; -} + 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 -#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); - unsigned int old, new; + if (IS_ENABLED(CONFIG_PPC_KERNEL_PCREL)) { + for (i = 0; i < 2; i++) { + reladdr = addr - (unsigned long)tramp[i]; - old = ftrace_call_replace(ip, stub, 0); - new = ftrace_call_replace(ip, addr, 0); + 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; + } - return ftrace_modify_code(ip, old, new); -} + 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(); -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); - unsigned int old, new; + 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; + } - old = ftrace_call_replace(ip, addr, 0); - new = ftrace_call_replace(ip, stub, 0); + 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 ftrace_modify_code(ip, old, new); + return 0; } -/* - * 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) +#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 return_hooker; + unsigned long sp = arch_ftrace_regs(fregs)->regs.gpr[1]; if (unlikely(ftrace_graph_is_dead())) goto out; @@ -955,21 +663,10 @@ unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip, if (unlikely(atomic_read(¤t->tracing_graph_pause))) goto out; - return_hooker = ppc_function_entry(return_to_handler); + if (!function_graph_enter_regs(parent_ip, ip, 0, (unsigned long *)sp, fregs)) + parent_ip = ppc_function_entry(return_to_handler); - if (!function_graph_enter(parent, ip, 0, (unsigned long *)sp)) - parent = return_hooker; out: - return parent; + arch_ftrace_regs(fregs)->regs.link = parent_ip; } #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 */ diff --git a/arch/powerpc/kernel/trace/ftrace_32.S b/arch/powerpc/kernel/trace/ftrace_32.S deleted file mode 100644 index e023ae59c429..000000000000 --- a/arch/powerpc/kernel/trace/ftrace_32.S +++ /dev/null @@ -1,95 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-or-later */ -/* - * Split from entry_32.S - */ - -#include <linux/magic.h> -#include <asm/reg.h> -#include <asm/ppc_asm.h> -#include <asm/asm-offsets.h> -#include <asm/ftrace.h> -#include <asm/export.h> - -_GLOBAL(mcount) -_GLOBAL(_mcount) - /* - * It is required that _mcount on PPC32 must preserve the - * link register. But we have r0 to play with. We use r0 - * to push the return address back to the caller of mcount - * into the ctr register, restore the link register and - * then jump back using the ctr register. - */ - mflr r0 - mtctr r0 - lwz r0, 4(r1) - mtlr r0 - bctr - -_GLOBAL(ftrace_caller) - MCOUNT_SAVE_FRAME - /* r3 ends up with link register */ - subi r3, r3, MCOUNT_INSN_SIZE -.globl ftrace_call -ftrace_call: - bl ftrace_stub - nop -#ifdef CONFIG_FUNCTION_GRAPH_TRACER -.globl ftrace_graph_call -ftrace_graph_call: - b ftrace_graph_stub -_GLOBAL(ftrace_graph_stub) -#endif - MCOUNT_RESTORE_FRAME - /* old link register ends up in ctr reg */ - bctr - -EXPORT_SYMBOL(_mcount) - -_GLOBAL(ftrace_stub) - blr - -#ifdef CONFIG_FUNCTION_GRAPH_TRACER -_GLOBAL(ftrace_graph_caller) - addi r5, r1, 48 - /* load r4 with local address */ - lwz r4, 44(r1) - subi r4, r4, MCOUNT_INSN_SIZE - - /* Grab the LR out of the caller stack frame */ - lwz r3,52(r1) - - bl prepare_ftrace_return - nop - - /* - * prepare_ftrace_return gives us the address we divert to. - * Change the LR in the callers stack frame to this. - */ - stw r3,52(r1) - - MCOUNT_RESTORE_FRAME - /* old link register ends up in ctr reg */ - bctr - -_GLOBAL(return_to_handler) - /* need to save return values */ - stwu r1, -32(r1) - stw r3, 20(r1) - stw r4, 16(r1) - stw r31, 12(r1) - mr r31, r1 - - bl ftrace_return_to_handler - nop - - /* return value has real return address */ - mtlr r3 - - lwz r3, 20(r1) - lwz r4, 16(r1) - lwz r31,12(r1) - lwz r1, 0(r1) - - /* Jump back to real return address */ - blr -#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ diff --git a/arch/powerpc/kernel/trace/ftrace_64.S b/arch/powerpc/kernel/trace/ftrace_64.S deleted file mode 100644 index 25e5b9e47c06..000000000000 --- a/arch/powerpc/kernel/trace/ftrace_64.S +++ /dev/null @@ -1,64 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-or-later */ -/* - * Split from entry_64.S - */ - -#include <linux/magic.h> -#include <asm/ppc_asm.h> -#include <asm/asm-offsets.h> -#include <asm/ftrace.h> -#include <asm/ppc-opcode.h> -#include <asm/export.h> - -.pushsection ".tramp.ftrace.text","aw",@progbits; -.globl ftrace_tramp_text -ftrace_tramp_text: - .space 64 -.popsection - -.pushsection ".tramp.ftrace.init","aw",@progbits; -.globl ftrace_tramp_init -ftrace_tramp_init: - .space 64 -.popsection - -_GLOBAL(mcount) -_GLOBAL(_mcount) -EXPORT_SYMBOL(_mcount) - mflr r12 - mtctr r12 - mtlr r0 - bctr - -#ifdef CONFIG_FUNCTION_GRAPH_TRACER -_GLOBAL(return_to_handler) - /* need to save return values */ - std r4, -32(r1) - std r3, -24(r1) - /* save TOC */ - std r2, -16(r1) - std r31, -8(r1) - mr r31, r1 - stdu r1, -112(r1) - - /* - * We might be called from a module. - * Switch to our TOC to run inside the core kernel. - */ - ld r2, PACATOC(r13) - - bl ftrace_return_to_handler - nop - - /* return value has real return address */ - mtlr r3 - - ld r1, 0(r1) - ld r4, -32(r1) - ld r3, -24(r1) - ld r2, -16(r1) - ld r31, -8(r1) - - /* Jump back to real return address */ - blr -#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ diff --git a/arch/powerpc/kernel/trace/ftrace_64_mprofile.S b/arch/powerpc/kernel/trace/ftrace_64_mprofile.S deleted file mode 100644 index f9fd5f743eba..000000000000 --- a/arch/powerpc/kernel/trace/ftrace_64_mprofile.S +++ /dev/null @@ -1,330 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-or-later */ -/* - * Split from ftrace_64.S - */ - -#include <linux/magic.h> -#include <asm/ppc_asm.h> -#include <asm/asm-offsets.h> -#include <asm/ftrace.h> -#include <asm/ppc-opcode.h> -#include <asm/export.h> -#include <asm/thread_info.h> -#include <asm/bug.h> -#include <asm/ptrace.h> - -/* - * - * ftrace_caller()/ftrace_regs_caller() is the function that replaces _mcount() - * when ftrace is active. - * - * We arrive here after a function A calls function B, and we are the trace - * function for B. When we enter r1 points to A's stack frame, B has not yet - * had a chance to allocate one yet. - * - * Additionally r2 may point either to the TOC for A, or B, depending on - * whether B did a TOC setup sequence before calling us. - * - * On entry the LR points back to the _mcount() call site, and r0 holds the - * saved LR as it was on entry to B, ie. the original return address at the - * call site in A. - * - * Our job is to save the register state into a struct pt_regs (on the stack) - * and then arrange for the ftrace function to be called. - */ -_GLOBAL(ftrace_regs_caller) - /* Save the original return address in A's stack frame */ - std r0,LRSAVE(r1) - - /* Create our stack frame + pt_regs */ - stdu r1,-SWITCH_FRAME_SIZE(r1) - - /* Save all gprs to pt_regs */ - SAVE_GPR(0, r1) - SAVE_10GPRS(2, r1) - - /* Ok to continue? */ - lbz r3, PACA_FTRACE_ENABLED(r13) - cmpdi r3, 0 - beq ftrace_no_trace - - SAVE_10GPRS(12, r1) - SAVE_10GPRS(22, r1) - - /* Save previous stack pointer (r1) */ - addi r8, r1, SWITCH_FRAME_SIZE - std r8, GPR1(r1) - - /* Load special regs for save below */ - mfmsr r8 - mfctr r9 - mfxer r10 - mfcr r11 - - /* Get the _mcount() call site out of LR */ - mflr r7 - /* Save it as pt_regs->nip */ - std r7, _NIP(r1) - /* Save the read LR in pt_regs->link */ - std r0, _LINK(r1) - - /* Save callee's TOC in the ABI compliant location */ - std r2, 24(r1) - ld r2,PACATOC(r13) /* get kernel TOC in r2 */ - - addis r3,r2,function_trace_op@toc@ha - addi r3,r3,function_trace_op@toc@l - ld r5,0(r3) - -#ifdef CONFIG_LIVEPATCH - mr r14,r7 /* remember old NIP */ -#endif - /* Calculate ip from nip-4 into r3 for call below */ - subi r3, r7, MCOUNT_INSN_SIZE - - /* Put the original return address in r4 as parent_ip */ - mr r4, r0 - - /* Save special regs */ - std r8, _MSR(r1) - std r9, _CTR(r1) - std r10, _XER(r1) - std r11, _CCR(r1) - - /* Load &pt_regs in r6 for call below */ - addi r6, r1 ,STACK_FRAME_OVERHEAD - - /* ftrace_call(r3, r4, r5, r6) */ -.globl ftrace_regs_call -ftrace_regs_call: - bl ftrace_stub - nop - - /* Load ctr with the possibly modified NIP */ - ld r3, _NIP(r1) - mtctr r3 -#ifdef CONFIG_LIVEPATCH - cmpd r14, r3 /* has NIP been altered? */ -#endif - - /* Restore gprs */ - REST_GPR(0,r1) - REST_10GPRS(2,r1) - REST_10GPRS(12,r1) - REST_10GPRS(22,r1) - - /* Restore possibly modified LR */ - ld r0, _LINK(r1) - mtlr r0 - - /* Restore callee's TOC */ - ld r2, 24(r1) - - /* Pop our stack frame */ - addi r1, r1, SWITCH_FRAME_SIZE - -#ifdef CONFIG_LIVEPATCH - /* Based on the cmpd above, if the NIP was altered handle livepatch */ - bne- livepatch_handler -#endif - -ftrace_caller_common: -#ifdef CONFIG_FUNCTION_GRAPH_TRACER -.globl ftrace_graph_call -ftrace_graph_call: - b ftrace_graph_stub -_GLOBAL(ftrace_graph_stub) -#endif - - bctr /* jump after _mcount site */ - -_GLOBAL(ftrace_stub) - blr - -ftrace_no_trace: - mflr r3 - mtctr r3 - REST_GPR(3, r1) - addi r1, r1, SWITCH_FRAME_SIZE - mtlr r0 - bctr - -_GLOBAL(ftrace_caller) - /* Save the original return address in A's stack frame */ - std r0, LRSAVE(r1) - - /* Create our stack frame + pt_regs */ - stdu r1, -SWITCH_FRAME_SIZE(r1) - - /* Save all gprs to pt_regs */ - SAVE_8GPRS(3, r1) - - lbz r3, PACA_FTRACE_ENABLED(r13) - cmpdi r3, 0 - beq ftrace_no_trace - - /* Get the _mcount() call site out of LR */ - mflr r7 - std r7, _NIP(r1) - - /* Save callee's TOC in the ABI compliant location */ - std r2, 24(r1) - ld r2, PACATOC(r13) /* get kernel TOC in r2 */ - - addis r3, r2, function_trace_op@toc@ha - addi r3, r3, function_trace_op@toc@l - ld r5, 0(r3) - - /* Calculate ip from nip-4 into r3 for call below */ - subi r3, r7, MCOUNT_INSN_SIZE - - /* Put the original return address in r4 as parent_ip */ - mr r4, r0 - - /* Set pt_regs to NULL */ - li r6, 0 - - /* ftrace_call(r3, r4, r5, r6) */ -.globl ftrace_call -ftrace_call: - bl ftrace_stub - nop - - ld r3, _NIP(r1) - mtctr r3 - - /* Restore gprs */ - REST_8GPRS(3,r1) - - /* Restore callee's TOC */ - ld r2, 24(r1) - - /* Pop our stack frame */ - addi r1, r1, SWITCH_FRAME_SIZE - - /* Reload original LR */ - ld r0, LRSAVE(r1) - mtlr r0 - - /* Handle function_graph or go back */ - b ftrace_caller_common - -#ifdef CONFIG_LIVEPATCH - /* - * This function runs in the mcount context, between two functions. As - * such it can only clobber registers which are volatile and used in - * function linkage. - * - * We get here when a function A, calls another function B, but B has - * been live patched with a new function C. - * - * On entry: - * - we have no stack frame and can not allocate one - * - LR points back to the original caller (in A) - * - CTR holds the new NIP in C - * - r0, r11 & r12 are free - */ -livepatch_handler: - ld r12, PACA_THREAD_INFO(r13) - - /* Allocate 3 x 8 bytes */ - ld r11, TI_livepatch_sp(r12) - addi r11, r11, 24 - std r11, TI_livepatch_sp(r12) - - /* Save toc & real LR on livepatch stack */ - std r2, -24(r11) - mflr r12 - std r12, -16(r11) - - /* Store stack end marker */ - lis r12, STACK_END_MAGIC@h - ori r12, r12, STACK_END_MAGIC@l - std r12, -8(r11) - - /* Put ctr in r12 for global entry and branch there */ - mfctr r12 - bctrl - - /* - * Now we are returning from the patched function to the original - * caller A. We are free to use r11, r12 and we can use r2 until we - * restore it. - */ - - ld r12, PACA_THREAD_INFO(r13) - - ld r11, TI_livepatch_sp(r12) - - /* Check stack marker hasn't been trashed */ - lis r2, STACK_END_MAGIC@h - ori r2, r2, STACK_END_MAGIC@l - ld r12, -8(r11) -1: tdne r12, r2 - EMIT_BUG_ENTRY 1b, __FILE__, __LINE__ - 1, 0 - - /* Restore LR & toc from livepatch stack */ - ld r12, -16(r11) - mtlr r12 - ld r2, -24(r11) - - /* Pop livepatch stack frame */ - ld r12, PACA_THREAD_INFO(r13) - subi r11, r11, 24 - std r11, TI_livepatch_sp(r12) - - /* Return to original caller of live patched function */ - blr -#endif /* CONFIG_LIVEPATCH */ - -#ifdef CONFIG_FUNCTION_GRAPH_TRACER -_GLOBAL(ftrace_graph_caller) - stdu r1, -112(r1) - /* with -mprofile-kernel, parameter regs are still alive at _mcount */ - std r10, 104(r1) - std r9, 96(r1) - std r8, 88(r1) - std r7, 80(r1) - std r6, 72(r1) - std r5, 64(r1) - std r4, 56(r1) - std r3, 48(r1) - - /* Save callee's TOC in the ABI compliant location */ - std r2, 24(r1) - ld r2, PACATOC(r13) /* get kernel TOC in r2 */ - - addi r5, r1, 112 - mfctr r4 /* ftrace_caller has moved local addr here */ - std r4, 40(r1) - mflr r3 /* ftrace_caller has restored LR from stack */ - subi r4, r4, MCOUNT_INSN_SIZE - - bl prepare_ftrace_return - nop - - /* - * prepare_ftrace_return gives us the address we divert to. - * Change the LR to this. - */ - mtlr r3 - - ld r0, 40(r1) - mtctr r0 - ld r10, 104(r1) - ld r9, 96(r1) - ld r8, 88(r1) - ld r7, 80(r1) - ld r6, 72(r1) - ld r5, 64(r1) - ld r4, 56(r1) - ld r3, 48(r1) - - /* Restore callee's TOC */ - ld r2, 24(r1) - - addi r1, r1, 112 - mflr r0 - std r0, LRSAVE(r1) - bctr -#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ diff --git a/arch/powerpc/kernel/trace/ftrace_64_pg.c b/arch/powerpc/kernel/trace/ftrace_64_pg.c new file mode 100644 index 000000000000..5c6e545d1708 --- /dev/null +++ b/arch/powerpc/kernel/trace/ftrace_64_pg.c @@ -0,0 +1,832 @@ +// 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/text-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]; + +unsigned long ftrace_call_adjust(unsigned long addr) +{ + return addr; +} + +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 struct module *ftrace_lookup_module(struct dyn_ftrace *rec) +{ + struct module *mod; + + scoped_guard(rcu) + mod = __module_text_address(rec->ip); + if (!mod) + pr_err("No module loaded at addr=%lx\n", rec->ip); + + return mod; +} + +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; + + if (!mod) { + mod = ftrace_lookup_module(rec); + if (!mod) + 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); + + 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; + } + + 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 = ftrace_lookup_module(rec); + + if (!mod) + return -EINVAL; + + /* 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; + } + + 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 = ftrace_lookup_module(rec); + + if (!mod) + return -EINVAL; + + /* 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; + } + + 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, + struct ftrace_regs *fregs) +{ + 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_regs(parent, ip, 0, (unsigned long *)sp, fregs)) + parent = return_hooker; + +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) +{ + arch_ftrace_regs(fregs)->regs.link = __prepare_ftrace_return(parent_ip, ip, + arch_ftrace_regs(fregs)->regs.gpr[1], fregs); +} +#else +unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip, + unsigned long sp) +{ + return __prepare_ftrace_return(parent, ip, sp, NULL); +} +#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 */ diff --git a/arch/powerpc/kernel/trace/ftrace_64_pg.S b/arch/powerpc/kernel/trace/ftrace_64_pg_entry.S index 6708e24db0ab..a8a7f28404c8 100644 --- a/arch/powerpc/kernel/trace/ftrace_64_pg.S +++ b/arch/powerpc/kernel/trace/ftrace_64_pg_entry.S @@ -3,12 +3,12 @@ * Split from ftrace_64.S */ +#include <linux/export.h> #include <linux/magic.h> #include <asm/ppc_asm.h> #include <asm/asm-offsets.h> #include <asm/ftrace.h> #include <asm/ppc-opcode.h> -#include <asm/export.h> _GLOBAL_TOC(ftrace_caller) lbz r3, PACA_FTRACE_ENABLED(r13) @@ -65,3 +65,68 @@ _GLOBAL(ftrace_graph_caller) addi r1, r1, 112 blr #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ + +.pushsection ".tramp.ftrace.text","aw",@progbits; +.globl ftrace_tramp_text +ftrace_tramp_text: + .space 32 +.popsection + +.pushsection ".tramp.ftrace.init","aw",@progbits; +.globl ftrace_tramp_init +ftrace_tramp_init: + .space 32 +.popsection + +_GLOBAL(mcount) +_GLOBAL(_mcount) +EXPORT_SYMBOL(_mcount) + mflr r12 + mtctr r12 + mtlr r0 + bctr + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +_GLOBAL(return_to_handler) + /* need to save return values */ +#ifdef CONFIG_PPC64 + std r4, -32(r1) + std r3, -24(r1) + /* save TOC */ + std r2, -16(r1) + std r31, -8(r1) + mr r31, r1 + stdu r1, -112(r1) + + /* + * We might be called from a module. + * Switch to our TOC to run inside the core kernel. + */ + LOAD_PACA_TOC() +#else + stwu r1, -16(r1) + stw r3, 8(r1) + stw r4, 12(r1) +#endif + + bl ftrace_return_to_handler + nop + + /* return value has real return address */ + mtlr r3 + +#ifdef CONFIG_PPC64 + ld r1, 0(r1) + ld r4, -32(r1) + ld r3, -24(r1) + ld r2, -16(r1) + ld r31, -8(r1) +#else + lwz r3, 8(r1) + lwz r4, 12(r1) + addi r1, r1, 16 +#endif + + /* Jump back to real return address */ + blr +#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ diff --git a/arch/powerpc/kernel/trace/ftrace_entry.S b/arch/powerpc/kernel/trace/ftrace_entry.S new file mode 100644 index 000000000000..3565c67fc638 --- /dev/null +++ b/arch/powerpc/kernel/trace/ftrace_entry.S @@ -0,0 +1,471 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Split from ftrace_64.S + */ + +#include <linux/export.h> +#include <linux/magic.h> +#include <asm/ppc_asm.h> +#include <asm/asm-offsets.h> +#include <asm/ftrace.h> +#include <asm/ppc-opcode.h> +#include <asm/thread_info.h> +#include <asm/bug.h> +#include <asm/ptrace.h> + +/* + * + * ftrace_caller()/ftrace_regs_caller() is the function that replaces _mcount() + * when ftrace is active. + * + * We arrive here after a function A calls function B, and we are the trace + * function for B. When we enter r1 points to A's stack frame, B has not yet + * had a chance to allocate one yet. + * + * Additionally r2 may point either to the TOC for A, or B, depending on + * whether B did a TOC setup sequence before calling us. + * + * On entry the LR points back to the _mcount() call site, and r0 holds the + * saved LR as it was on entry to B, ie. the original return address at the + * call site in A. + * + * Our job is to save the register state into a struct pt_regs (on the stack) + * and then arrange for the ftrace function to be called. + */ +.macro ftrace_regs_entry allregs + /* Create a minimal stack frame for representing B */ + PPC_STLU r1, -STACK_FRAME_MIN_SIZE(r1) + + /* Create our stack frame + pt_regs */ + PPC_STLU r1,-SWITCH_FRAME_SIZE(r1) + + .if \allregs == 1 + SAVE_GPRS(11, 12, r1) + .endif + + /* Get the _mcount() call site out of LR */ + mflr r11 + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS + /* Load the ftrace_op */ + PPC_LL r12, -(MCOUNT_INSN_SIZE*2 + SZL)(r11) + + /* Load direct_call from the ftrace_op */ + PPC_LL r12, FTRACE_OPS_DIRECT_CALL(r12) + PPC_LCMPI r12, 0 + .if \allregs == 1 + bne .Lftrace_direct_call_regs + .else + bne .Lftrace_direct_call + .endif +#endif + + /* Save the previous LR in pt_regs->link */ + PPC_STL r0, _LINK(r1) + /* Also save it in A's stack frame */ + PPC_STL r0, SWITCH_FRAME_SIZE+STACK_FRAME_MIN_SIZE+LRSAVE(r1) + + /* Save all gprs to pt_regs */ + SAVE_GPR(0, r1) + SAVE_GPRS(3, 10, r1) + +#ifdef CONFIG_PPC64 + /* Ok to continue? */ + lbz r3, PACA_FTRACE_ENABLED(r13) + cmpdi r3, 0 + beq ftrace_no_trace +#endif + + .if \allregs == 1 + SAVE_GPR(2, r1) + SAVE_GPRS(13, 31, r1) + .else +#if defined(CONFIG_LIVEPATCH_64) || defined(CONFIG_PPC_FTRACE_OUT_OF_LINE) + SAVE_GPR(14, r1) +#endif + .endif + + /* Save previous stack pointer (r1) */ + addi r8, r1, SWITCH_FRAME_SIZE+STACK_FRAME_MIN_SIZE + PPC_STL r8, GPR1(r1) + + .if \allregs == 1 + /* Load special regs for save below */ + mfcr r7 + mfmsr r8 + mfctr r9 + mfxer r10 + .else + /* Clear MSR to flag as ftrace_caller versus frace_regs_caller */ + li r8, 0 + .endif + +#ifdef CONFIG_PPC64 + /* Save callee's TOC in the ABI compliant location */ + std r2, STK_GOT(r1) + LOAD_PACA_TOC() /* get kernel TOC in r2 */ +#endif + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS + /* r11 points to the instruction following the call to ftrace */ + PPC_LL r5, -(MCOUNT_INSN_SIZE*2 + SZL)(r11) + PPC_LL r12, FTRACE_OPS_FUNC(r5) + mtctr r12 +#else /* !CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS */ +#ifdef CONFIG_PPC64 + LOAD_REG_ADDR(r3, function_trace_op) + ld r5,0(r3) +#else + lis r3,function_trace_op@ha + lwz r5,function_trace_op@l(r3) +#endif +#endif + + /* Save special regs */ + PPC_STL r8, _MSR(r1) + .if \allregs == 1 + PPC_STL r7, _CCR(r1) + PPC_STL r9, _CTR(r1) + PPC_STL r10, _XER(r1) + .endif + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS + /* Clear orig_gpr3 to later detect ftrace_direct call */ + li r7, 0 + PPC_STL r7, ORIG_GPR3(r1) +#endif + +#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE + /* Save our real return address in nvr for return */ + .if \allregs == 0 + SAVE_GPR(15, r1) + .endif + mr r15, r11 + /* + * We want the ftrace location in the function, but our lr (in r11) + * points at the 'mtlr r0' instruction in the out of line stub. To + * recover the ftrace location, we read the branch instruction in the + * stub, and adjust our lr by the branch offset. + * + * See ftrace_init_ool_stub() for the profile sequence. + */ + lwz r8, MCOUNT_INSN_SIZE(r11) + slwi r8, r8, 6 + srawi r8, r8, 6 + add r3, r11, r8 + /* + * Override our nip to point past the branch in the original function. + * This allows reliable stack trace and the ftrace stack tracer to work as-is. + */ + addi r11, r3, MCOUNT_INSN_SIZE +#else + /* Calculate ip from nip-4 into r3 for call below */ + subi r3, r11, MCOUNT_INSN_SIZE +#endif + + /* Save NIP as pt_regs->nip */ + PPC_STL r11, _NIP(r1) + /* Also save it in B's stackframe header for proper unwind */ + PPC_STL r11, LRSAVE+SWITCH_FRAME_SIZE(r1) +#if defined(CONFIG_LIVEPATCH_64) || defined(CONFIG_PPC_FTRACE_OUT_OF_LINE) + mr r14, r11 /* remember old NIP */ +#endif + + /* Put the original return address in r4 as parent_ip */ + mr r4, r0 + + /* Load &pt_regs in r6 for call below */ + addi r6, r1, STACK_INT_FRAME_REGS +.endm + +.macro ftrace_regs_exit allregs +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS + /* Check orig_gpr3 to detect ftrace_direct call */ + PPC_LL r3, ORIG_GPR3(r1) + PPC_LCMPI cr1, r3, 0 + mtctr r3 +#endif + + /* Restore possibly modified LR */ + PPC_LL r0, _LINK(r1) + +#ifndef CONFIG_PPC_FTRACE_OUT_OF_LINE + /* Load ctr with the possibly modified NIP */ + PPC_LL r3, _NIP(r1) +#ifdef CONFIG_LIVEPATCH_64 + cmpd r14, r3 /* has NIP been altered? */ +#endif + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS + beq cr1,2f + mtlr r3 + b 3f +#endif +2: mtctr r3 + mtlr r0 +3: + +#else /* !CONFIG_PPC_FTRACE_OUT_OF_LINE */ + /* Load LR with the possibly modified NIP */ + PPC_LL r3, _NIP(r1) + cmpd r14, r3 /* has NIP been altered? */ + bne- 1f + + mr r3, r15 +1: mtlr r3 + .if \allregs == 0 + REST_GPR(15, r1) + .endif +#endif + + /* Restore gprs */ + .if \allregs == 1 + REST_GPRS(2, 31, r1) + .else + REST_GPRS(3, 10, r1) +#if defined(CONFIG_LIVEPATCH_64) || defined(CONFIG_PPC_FTRACE_OUT_OF_LINE) + REST_GPR(14, r1) +#endif + .endif + +#ifdef CONFIG_PPC64 + /* Restore callee's TOC */ + ld r2, STK_GOT(r1) +#endif + + /* Pop our stack frame */ + addi r1, r1, SWITCH_FRAME_SIZE+STACK_FRAME_MIN_SIZE + +#ifdef CONFIG_LIVEPATCH_64 + /* Based on the cmpd above, if the NIP was altered handle livepatch */ + bne- livepatch_handler +#endif + + /* jump after _mcount site */ +#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS + bnectr cr1 +#endif + /* + * Return with blr to keep the link stack balanced. The function profiling sequence + * uses 'mtlr r0' to restore LR. + */ + blr +#else + bctr +#endif +.endm + +.macro ftrace_regs_func allregs +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS + bctrl +#else + .if \allregs == 1 +.globl ftrace_regs_call +ftrace_regs_call: + .else +.globl ftrace_call +ftrace_call: + .endif + /* ftrace_call(r3, r4, r5, r6) */ + bl ftrace_stub +#endif +.endm + +_GLOBAL(ftrace_regs_caller) + ftrace_regs_entry 1 + ftrace_regs_func 1 + ftrace_regs_exit 1 + +_GLOBAL(ftrace_caller) + ftrace_regs_entry 0 + ftrace_regs_func 0 + ftrace_regs_exit 0 + +_GLOBAL(ftrace_stub) + blr + +#ifdef CONFIG_PPC64 +ftrace_no_trace: +#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE + REST_GPR(3, r1) + addi r1, r1, SWITCH_FRAME_SIZE+STACK_FRAME_MIN_SIZE + blr +#else + mflr r3 + mtctr r3 + REST_GPR(3, r1) + addi r1, r1, SWITCH_FRAME_SIZE+STACK_FRAME_MIN_SIZE + mtlr r0 + bctr +#endif +#endif + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS +.Lftrace_direct_call_regs: + mtctr r12 + REST_GPRS(11, 12, r1) + addi r1, r1, SWITCH_FRAME_SIZE+STACK_FRAME_MIN_SIZE + bctr +.Lftrace_direct_call: + mtctr r12 + addi r1, r1, SWITCH_FRAME_SIZE+STACK_FRAME_MIN_SIZE + bctr +SYM_FUNC_START(ftrace_stub_direct_tramp) + blr +SYM_FUNC_END(ftrace_stub_direct_tramp) +#endif + +#ifdef CONFIG_LIVEPATCH_64 + /* + * This function runs in the mcount context, between two functions. As + * such it can only clobber registers which are volatile and used in + * function linkage. + * + * We get here when a function A, calls another function B, but B has + * been live patched with a new function C. + * + * On entry, we have no stack frame and can not allocate one. + * + * With PPC_FTRACE_OUT_OF_LINE=n, on entry: + * - LR points back to the original caller (in A) + * - CTR holds the new NIP in C + * - r0, r11 & r12 are free + * + * With PPC_FTRACE_OUT_OF_LINE=y, on entry: + * - r0 points back to the original caller (in A) + * - LR holds the new NIP in C + * - r11 & r12 are free + */ +livepatch_handler: + ld r12, PACA_THREAD_INFO(r13) + + /* Allocate 3 x 8 bytes */ + ld r11, TI_livepatch_sp(r12) + addi r11, r11, 24 + std r11, TI_livepatch_sp(r12) + + /* Store stack end marker */ + lis r12, STACK_END_MAGIC@h + ori r12, r12, STACK_END_MAGIC@l + std r12, -8(r11) + + /* Save toc & real LR on livepatch stack */ + std r2, -24(r11) +#ifndef CONFIG_PPC_FTRACE_OUT_OF_LINE + mflr r12 + std r12, -16(r11) + mfctr r12 +#else + std r0, -16(r11) + mflr r12 + /* Put ctr in r12 for global entry and branch there */ + mtctr r12 +#endif + bctrl + + /* + * Now we are returning from the patched function to the original + * caller A. We are free to use r11, r12 and we can use r2 until we + * restore it. + */ + + ld r12, PACA_THREAD_INFO(r13) + + ld r11, TI_livepatch_sp(r12) + + /* Check stack marker hasn't been trashed */ + lis r2, STACK_END_MAGIC@h + ori r2, r2, STACK_END_MAGIC@l + ld r12, -8(r11) +1: tdne r12, r2 + EMIT_BUG_ENTRY 1b, __FILE__, __LINE__ - 1, 0 + + /* Restore LR & toc from livepatch stack */ + ld r12, -16(r11) + mtlr r12 + ld r2, -24(r11) + + /* Pop livepatch stack frame */ + ld r12, PACA_THREAD_INFO(r13) + subi r11, r11, 24 + std r11, TI_livepatch_sp(r12) + + /* Return to original caller of live patched function */ + blr +#endif /* CONFIG_LIVEPATCH */ + +#ifndef CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY +_GLOBAL(mcount) +_GLOBAL(_mcount) +EXPORT_SYMBOL(_mcount) + mflr r12 + mtctr r12 + mtlr r0 + bctr +#endif + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +_GLOBAL(return_to_handler) + /* need to save return values */ +#ifdef CONFIG_PPC64 + std r4, -32(r1) + std r3, -24(r1) + /* save TOC */ + std r2, -16(r1) + std r31, -8(r1) + mr r31, r1 + stdu r1, -112(r1) + + /* + * We might be called from a module. + * Switch to our TOC to run inside the core kernel. + */ + LOAD_PACA_TOC() +#else + stwu r1, -16(r1) + stw r3, 8(r1) + stw r4, 12(r1) +#endif + + bl ftrace_return_to_handler + nop + + /* return value has real return address */ + mtlr r3 + +#ifdef CONFIG_PPC64 + ld r1, 0(r1) + ld r4, -32(r1) + ld r3, -24(r1) + ld r2, -16(r1) + ld r31, -8(r1) +#else + lwz r3, 8(r1) + lwz r4, 12(r1) + addi r1, r1, 16 +#endif + + /* Jump back to real return address */ + blr +#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ + +#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE +SYM_DATA(ftrace_ool_stub_text_count, .long CONFIG_PPC_FTRACE_OUT_OF_LINE_NUM_RESERVE) + +SYM_START(ftrace_ool_stub_text, SYM_L_GLOBAL, .balign SZL) + .space CONFIG_PPC_FTRACE_OUT_OF_LINE_NUM_RESERVE * FTRACE_OOL_STUB_SIZE +SYM_CODE_END(ftrace_ool_stub_text) +#endif + +.pushsection ".tramp.ftrace.text","aw",@progbits; +.globl ftrace_tramp_text +ftrace_tramp_text: + .space 32 +.popsection + +.pushsection ".tramp.ftrace.init","aw",@progbits; +.globl ftrace_tramp_init +ftrace_tramp_init: + .space 32 +.popsection |