Le 19/05/2023 à 21:26, Naveen N Rao a écrit : > [Vous ne recevez pas souvent de courriers de nav...@kernel.org. Découvrez > pourquoi ceci est important à https://aka.ms/LearnAboutSenderIdentification ] > > Refactor ftrace code and move to using ftrace_replace_code() to help > simplify and make the code more maintainable. > > - The existing ftrace.c code is moved to a separate file so that ppc64 > elfv1 and clang -pg only support continue. This makes it possible to > converge ppc32 and ppc64 support further. > - Drop code to re-purpose compiler-generated long branches for ftrace > use in support of large kernels. We still retain the ftrace stubs at > the end of .text, so we now support kernels upto ~64MB. > - Add ftrace_init_nop() to keep boot-time validations and init separate > from runtime. > - Implement ftrace_replace_code() to simplify overall ftrace setup. This > will be especially useful when adding ability to nop out 'mflr r0' > later, and for other subsequent ftrace features. > - Add support for -fpatchable-function-entry. On ppc64, this needs gcc > v13.1 so that the nops are generated at LEP. This also moves ppc32 to > using the same two-instruction sequence as that of ppc64. > > This applies atop patches 1-3 of Nick's series for elfv2 conversion, as > well as Nick's patch enabling -mprofile-kernel for elfv2 BE: > - https://lore.kernel.org/all/20230505071850.228734-1-npig...@gmail.com/ > - https://lore.kernel.org/all/20230506011814.8766-1-npig...@gmail.com/ > > This builds for me and passes a quick test, posting this as an early > RFC. > > Signed-off-by: Naveen N Rao <nav...@kernel.org>
Looks good, works on PPC32 but I observed some performance degradation, around 25% more time needed to activate function tracer and around 10% more time needed to de-activate function tracer (by writting function/nop into /sys/kernel/debug/tracing/current_tracer. Note that the trampoline at end of .text is only on PPC64 at the moment, so if PPC32 kernel goes beyond 32M we will have a problem (it happens with allyesconfig). It should be easy to extend it to PPC32. At the begining of ftrace_replace_code(), don't you miss: if (unlikely(ftrace_disabled)) return; Below fix needed in order to build: diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c index a9d57f338bd7..81d5bd69b660 100644 --- a/arch/powerpc/kernel/trace/ftrace.c +++ b/arch/powerpc/kernel/trace/ftrace.c @@ -96,7 +96,6 @@ static unsigned long find_ftrace_tramp(unsigned long ip) static int ftrace_get_call_inst(struct dyn_ftrace *rec, unsigned long addr, ppc_inst_t *call_inst) { - struct module *mod = rec->arch.mod; unsigned long ip = rec->ip; unsigned long stub; @@ -112,7 +111,11 @@ static int ftrace_get_call_inst(struct dyn_ftrace *rec, unsigned long addr, ppc_ } } else if (IS_ENABLED(CONFIG_MODULES)) { /* Module code would be going to one of the module stubs */ +#ifdef CONFIG_MODULES + struct module *mod = rec->arch.mod; + stub = (addr == (unsigned long)ftrace_caller ? mod->arch.tramp : mod->arch.tramp_regs); +#endif } else { return -EINVAL; } Christophe > --- > arch/powerpc/Kconfig | 10 + > arch/powerpc/Makefile | 5 + > arch/powerpc/include/asm/ftrace.h | 10 +- > arch/powerpc/include/asm/module.h | 4 - > arch/powerpc/kernel/trace/Makefile | 8 +- > arch/powerpc/kernel/trace/ftrace.c | 816 +++++------------ > arch/powerpc/kernel/trace/ftrace_pg.c | 846 ++++++++++++++++++ > .../gcc-check-fpatchable-function-entry.sh | 20 + > 8 files changed, 1106 insertions(+), 613 deletions(-) > create mode 100644 arch/powerpc/kernel/trace/ftrace_pg.c > create mode 100755 arch/powerpc/tools/gcc-check-fpatchable-function-entry.sh > > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > index 902b6b99f7ecd5..6db94723af7d30 100644 > --- a/arch/powerpc/Kconfig > +++ b/arch/powerpc/Kconfig > @@ -187,6 +187,7 @@ config PPC > select DYNAMIC_FTRACE if FUNCTION_TRACER > select EDAC_ATOMIC_SCRUB > select EDAC_SUPPORT > + select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY if > ARCH_USING_PATCHABLE_FUNCTION_ENTRY > select GENERIC_ATOMIC64 if PPC32 > select GENERIC_CLOCKEVENTS_BROADCAST if SMP > select GENERIC_CMOS_UPDATE > @@ -552,6 +553,15 @@ config MPROFILE_KERNEL > def_bool > $(success,$(srctree)/arch/powerpc/tools/gcc-check-mprofile-kernel.sh $(CC) > -mlittle-endian) if CPU_LITTLE_ENDIAN > def_bool > $(success,$(srctree)/arch/powerpc/tools/gcc-check-mprofile-kernel.sh $(CC) > -mbig-endian) if CPU_BIG_ENDIAN > > +config ARCH_HAS_PATCHABLE_FUNCTION_ENTRY_AT_LEP > + depends on PPC64_ELF_ABI_V2 && FUNCTION_TRACER > + def_bool > $(success,$(srctree)/arch/powerpc/tools/gcc-check-fpatchable-function-entry.sh > $(CC) -mlittle-endian) if CPU_LITTLE_ENDIAN > + def_bool > $(success,$(srctree)/arch/powerpc/tools/gcc-check-fpatchable-function-entry.sh > $(CC) -mbig-endian) if CPU_BIG_ENDIAN > + > +config ARCH_USING_PATCHABLE_FUNCTION_ENTRY > + depends on FUNCTION_TRACER && (PPC32 || PPC64_ELF_ABI_V2) > + def_bool ARCH_HAS_PATCHABLE_FUNCTION_ENTRY_AT_LEP || (PPC32 && > $(cc-option, -fpatchable-function-entry=2)) > + > config HOTPLUG_CPU > bool "Support for enabling/disabling CPUs" > depends on SMP && (PPC_PSERIES || \ > diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile > index dca73f673d7046..de39478b1c9e9f 100644 > --- a/arch/powerpc/Makefile > +++ b/arch/powerpc/Makefile > @@ -148,11 +148,16 @@ CFLAGS-$(CONFIG_PPC32) += $(call cc-option, > $(MULTIPLEWORD)) > CFLAGS-$(CONFIG_PPC32) += $(call cc-option,-mno-readonly-in-sdata) > > ifdef CONFIG_FUNCTION_TRACER > +ifdef CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY > +KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY > +CC_FLAGS_FTRACE := -fpatchable-function-entry=2 > +else > CC_FLAGS_FTRACE := -pg > ifdef CONFIG_MPROFILE_KERNEL > CC_FLAGS_FTRACE += -mprofile-kernel > endif > endif > +endif > > CFLAGS-$(CONFIG_TARGET_CPU_BOOL) += -mcpu=$(CONFIG_TARGET_CPU) > AFLAGS-$(CONFIG_TARGET_CPU_BOOL) += -mcpu=$(CONFIG_TARGET_CPU) > diff --git a/arch/powerpc/include/asm/ftrace.h > b/arch/powerpc/include/asm/ftrace.h > index 91c049d51d0e10..d1a16543a37b00 100644 > --- a/arch/powerpc/include/asm/ftrace.h > +++ b/arch/powerpc/include/asm/ftrace.h > @@ -22,18 +22,26 @@ extern void _mcount(void); > > static inline unsigned long ftrace_call_adjust(unsigned long addr) > { > - /* relocation of mcount call site is the same as the address */ > + if (IS_ENABLED(CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY)) > + addr += MCOUNT_INSN_SIZE; > + > return addr; > } > > unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip, > unsigned long sp); > > +struct module; > +struct dyn_ftrace; > struct dyn_arch_ftrace { > struct module *mod; > }; > > #ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS > +#define ftrace_need_init_nop() (true) > +int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec); > +#define ftrace_init_nop ftrace_init_nop > + > struct ftrace_regs { > struct pt_regs regs; > }; > diff --git a/arch/powerpc/include/asm/module.h > b/arch/powerpc/include/asm/module.h > index ac53606c259430..a8e2e8339fb7f4 100644 > --- a/arch/powerpc/include/asm/module.h > +++ b/arch/powerpc/include/asm/module.h > @@ -75,10 +75,6 @@ struct mod_arch_specific { > #endif > > #ifdef CONFIG_DYNAMIC_FTRACE > -# ifdef MODULE > - asm(".section .ftrace.tramp,\"ax\",@nobits; .align 3; .previous"); > -# endif /* MODULE */ > - > int module_trampoline_target(struct module *mod, unsigned long trampoline, > unsigned long *target); > int module_finalize_ftrace(struct module *mod, const Elf_Shdr *sechdrs); > diff --git a/arch/powerpc/kernel/trace/Makefile > b/arch/powerpc/kernel/trace/Makefile > index b16a9f9c0b35f2..2296bbbd775ac8 100644 > --- a/arch/powerpc/kernel/trace/Makefile > +++ b/arch/powerpc/kernel/trace/Makefile > @@ -8,13 +8,13 @@ ifdef CONFIG_FUNCTION_TRACER > CFLAGS_REMOVE_ftrace.o = $(CC_FLAGS_FTRACE) > endif > > -obj32-$(CONFIG_FUNCTION_TRACER) += ftrace_mprofile.o > +obj32-$(CONFIG_FUNCTION_TRACER) += ftrace_mprofile.o ftrace.o > ifdef CONFIG_MPROFILE_KERNEL > -obj64-$(CONFIG_FUNCTION_TRACER) += ftrace_mprofile.o > +obj64-$(CONFIG_FUNCTION_TRACER) += ftrace_mprofile.o ftrace.o > else > -obj64-$(CONFIG_FUNCTION_TRACER) += ftrace_64_pg.o > +obj64-$(CONFIG_FUNCTION_TRACER) += ftrace_64_pg.o ftrace_pg.o > endif > -obj-$(CONFIG_FUNCTION_TRACER) += ftrace_low.o ftrace.o > +obj-$(CONFIG_FUNCTION_TRACER) += ftrace_low.o > obj-$(CONFIG_TRACING) += trace_clock.o > > obj-$(CONFIG_PPC64) += $(obj64-y) > diff --git a/arch/powerpc/kernel/trace/ftrace.c > b/arch/powerpc/kernel/trace/ftrace.c > index a47f303734233b..a9d57f338bd78e 100644 > --- a/arch/powerpc/kernel/trace/ftrace.c > +++ b/arch/powerpc/kernel/trace/ftrace.c > @@ -28,64 +28,52 @@ > #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 > +#define NUM_FTRACE_TRAMPS 2 > static unsigned long ftrace_tramps[NUM_FTRACE_TRAMPS]; > > -static ppc_inst_t > -ftrace_call_replace(unsigned long ip, unsigned long addr, int link) > +static ppc_inst_t ftrace_create_branch_inst(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' */ > + WARN_ON(!is_offset_in_branch_range(addr - ip)); > 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) > +static inline int ftrace_read_inst(unsigned long ip, ppc_inst_t *op) > { > - 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)) > + if (copy_inst_from_kernel_nofault(op, (void *)ip)) { > + pr_err("0x%lx: fetching instruction failed\n", 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); > + return 0; > } > > -/* > - * Helper functions that are the same for both PPC64 and PPC32. > - */ > -static int test_24bit_addr(unsigned long ip, unsigned long addr) > +static inline int ftrace_validate_inst(unsigned long ip, ppc_inst_t inst) > { > - addr = ppc_function_entry((void *)addr); > + ppc_inst_t op; > + int ret; > > - return is_offset_in_branch_range(addr - ip); > + 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; > + } > + > + return ret; > +} > + > +static inline int ftrace_modify_code(unsigned long ip, ppc_inst_t old, > ppc_inst_t new) > +{ > + int ret = ftrace_validate_inst(ip, old); > + > + if (!ret) > + ret = patch_instruction((u32 *)ip, new); > + > + return ret; > } > > static int is_bl_op(ppc_inst_t op) > @@ -93,138 +81,11 @@ static int is_bl_op(ppc_inst_t op) > return (ppc_inst_val(op) & ~PPC_LI_MASK) == PPC_RAW_BL(0); > } > > -static int is_b_op(ppc_inst_t op) > -{ > - return (ppc_inst_val(op) & ~PPC_LI_MASK) == PPC_RAW_BRANCH(0); > -} > - > -static unsigned long find_bl_target(unsigned long ip, ppc_inst_t op) > -{ > - int offset; > - > - offset = PPC_LI(ppc_inst_val(op)); > - /* make it signed */ > - if (offset & 0x02000000) > - offset |= 0xfe000000; > - > - return ip + (long)offset; > -} > - > -#ifdef CONFIG_MODULES > -static int > -__ftrace_make_nop(struct module *mod, > - struct dyn_ftrace *rec, unsigned long addr) > -{ > - unsigned long entry, ptr, tramp; > - unsigned long ip = rec->ip; > - ppc_inst_t op, pop; > - > - /* read where this goes */ > - if (copy_inst_from_kernel_nofault(&op, (void *)ip)) { > - pr_err("Fetching opcode failed.\n"); > - return -EFAULT; > - } > - > - /* Make sure that this is still a 24bit jump */ > - if (!is_bl_op(op)) { > - pr_err("Not expected bl: opcode is %08lx\n", > ppc_inst_as_ulong(op)); > - return -EINVAL; > - } > - > - /* lets find where the pointer goes */ > - tramp = find_bl_target(ip, op); > - > - pr_devel("ip:%lx jumps to %lx", ip, tramp); > - > - if (module_trampoline_target(mod, tramp, &ptr)) { > - pr_err("Failed to get trampoline target\n"); > - return -EFAULT; > - } > - > - pr_devel("trampoline target %lx", ptr); > - > - entry = ppc_global_function_entry((void *)addr); > - /* This should match what was called */ > - if (ptr != entry) { > - pr_err("addr %lx does not match expected %lx\n", ptr, entry); > - return -EINVAL; > - } > - > - if (IS_ENABLED(CONFIG_MPROFILE_KERNEL)) { > - if (copy_inst_from_kernel_nofault(&op, (void *)(ip - 4))) { > - pr_err("Fetching instruction at %lx failed.\n", ip - > 4); > - return -EFAULT; > - } > - > - /* We expect either a mflr r0, or a std r0, LRSAVE(r1) */ > - if (!ppc_inst_equal(op, ppc_inst(PPC_RAW_MFLR(_R0))) && > - !ppc_inst_equal(op, ppc_inst(PPC_INST_STD_LR))) { > - pr_err("Unexpected instruction %08lx around bl > _mcount\n", > - ppc_inst_as_ulong(op)); > - return -EINVAL; > - } > - } else if (IS_ENABLED(CONFIG_PPC64)) { > - /* > - * Check what is in the next instruction. We can see ld > r2,40(r1), but > - * on first pass after boot we will see mflr r0. > - */ > - if (copy_inst_from_kernel_nofault(&op, (void *)(ip + 4))) { > - pr_err("Fetching op failed.\n"); > - return -EFAULT; > - } > - > - if (!ppc_inst_equal(op, ppc_inst(PPC_INST_LD_TOC))) { > - pr_err("Expected %08lx found %08lx\n", > PPC_INST_LD_TOC, > - ppc_inst_as_ulong(op)); > - return -EINVAL; > - } > - } > - > - /* > - * When using -mprofile-kernel or PPC32 there is no load to jump over. > - * > - * Otherwise our original call site looks like: > - * > - * bl <tramp> > - * ld r2,XX(r1) > - * > - * Milton Miller pointed out that we can not simply nop the branch. > - * If a task was preempted when calling a trace function, the nops > - * will remove the way to restore the TOC in r2 and the r2 TOC will > - * get corrupted. > - * > - * Use a b +8 to jump over the load. > - * XXX: could make PCREL depend on MPROFILE_KERNEL > - * XXX: check PCREL && MPROFILE_KERNEL calling sequence > - */ > - 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--) > + for (i = 0; i < NUM_FTRACE_TRAMPS; i++) > if (!ftrace_tramps[i]) > continue; > else if (is_offset_in_branch_range(ftrace_tramps[i] - ip)) > @@ -233,449 +94,200 @@ static unsigned long find_ftrace_tramp(unsigned long > ip) > return 0; > } > > -static int add_ftrace_tramp(unsigned long tramp) > +static int ftrace_get_call_inst(struct dyn_ftrace *rec, unsigned long addr, > ppc_inst_t *call_inst) > { > - int i; > - > - for (i = 0; i < NUM_FTRACE_TRAMPS; i++) > - if (!ftrace_tramps[i]) { > - ftrace_tramps[i] = tramp; > - return 0; > - } > - > - return -1; > -} > - > -/* > - * If this is a compiler generated long_branch trampoline (essentially, a > - * trampoline that has a branch to _mcount()), we re-write the branch to > - * instead go to ftrace_[regs_]caller() and note down the location of this > - * trampoline. > - */ > -static int setup_mcount_compiler_tramp(unsigned long tramp) > -{ > - int i; > - ppc_inst_t op; > - unsigned long ptr; > - > - /* Is this a known long jump tramp? */ > - for (i = 0; i < NUM_FTRACE_TRAMPS; i++) > - if (ftrace_tramps[i] == tramp) > - return 0; > - > - /* New trampoline -- read where this goes */ > - if (copy_inst_from_kernel_nofault(&op, (void *)tramp)) { > - pr_debug("Fetching opcode failed.\n"); > - return -1; > - } > - > - /* Is this a 24 bit branch? */ > - if (!is_b_op(op)) { > - pr_debug("Trampoline is not a long branch tramp.\n"); > - return -1; > - } > - > - /* lets find where the pointer goes */ > - ptr = find_bl_target(tramp, op); > - > - if (ptr != ppc_global_function_entry((void *)_mcount)) { > - pr_debug("Trampoline target %p is not _mcount\n", (void > *)ptr); > - return -1; > - } > - > - /* Let's re-write the tramp to go to ftrace_[regs_]caller */ > - if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS)) > - ptr = ppc_global_function_entry((void *)ftrace_regs_caller); > - else > - ptr = ppc_global_function_entry((void *)ftrace_caller); > - > - if (patch_branch((u32 *)tramp, ptr, 0)) { > - pr_debug("REL24 out of range!\n"); > - return -1; > - } > - > - if (add_ftrace_tramp(tramp)) { > - pr_debug("No tramp locations left\n"); > - return -1; > - } > - > - return 0; > -} > - > -static int __ftrace_make_nop_kernel(struct dyn_ftrace *rec, unsigned long > addr) > -{ > - unsigned long tramp, ip = rec->ip; > - ppc_inst_t op; > - > - /* Read where this goes */ > - if (copy_inst_from_kernel_nofault(&op, (void *)ip)) { > - pr_err("Fetching opcode failed.\n"); > - return -EFAULT; > - } > - > - /* Make sure that this is still a 24bit jump */ > - if (!is_bl_op(op)) { > - pr_err("Not expected bl: opcode is %08lx\n", > ppc_inst_as_ulong(op)); > - return -EINVAL; > - } > - > - /* Let's find where the pointer goes */ > - tramp = find_bl_target(ip, op); > - > - pr_devel("ip:%lx jumps to %lx", ip, tramp); > - > - if (setup_mcount_compiler_tramp(tramp)) { > - /* Are other trampolines reachable? */ > - if (!find_ftrace_tramp(ip)) { > - pr_err("No ftrace trampolines reachable from %ps\n", > - (void *)ip); > - return -EINVAL; > - } > - } > - > - if (patch_instruction((u32 *)ip, ppc_inst(PPC_RAW_NOP()))) { > - pr_err("Patching NOP failed.\n"); > - return -EPERM; > - } > - > - return 0; > -} > - > -int ftrace_make_nop(struct module *mod, > - struct dyn_ftrace *rec, unsigned long addr) > -{ > - unsigned long ip = rec->ip; > - ppc_inst_t old, new; > - > - /* > - * If the calling address is more that 24 bits away, > - * then we had to use a trampoline to make the call. > - * Otherwise just update the call site. > - */ > - if (test_24bit_addr(ip, addr)) { > - /* within range */ > - old = ftrace_call_replace(ip, addr, 1); > - new = ppc_inst(PPC_RAW_NOP()); > - return ftrace_modify_code(ip, old, new); > - } else if (core_kernel_text(ip)) { > - return __ftrace_make_nop_kernel(rec, addr); > - } else if (!IS_ENABLED(CONFIG_MODULES)) { > - return -EINVAL; > - } > - > - /* > - * Out of range jumps are called from modules. > - * We should either already have a pointer to the module > - * or it has been passed in. > - */ > - if (!rec->arch.mod) { > - if (!mod) { > - pr_err("No module loaded addr=%lx\n", addr); > - return -EFAULT; > - } > - rec->arch.mod = mod; > - } else if (mod) { > - if (mod != rec->arch.mod) { > - pr_err("Record mod %p not equal to passed in mod > %p\n", > - rec->arch.mod, mod); > - return -EINVAL; > - } > - /* nothing to do if mod == rec->arch.mod */ > - } else > - mod = rec->arch.mod; > - > - return __ftrace_make_nop(mod, rec, addr); > -} > - > -#ifdef CONFIG_MODULES > -/* > - * Examine the existing instructions for __ftrace_make_call. > - * They should effectively be a NOP, and follow formal constraints, > - * depending on the ABI. Return false if they don't. > - */ > -static bool expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1) > -{ > - if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS)) > - return ppc_inst_equal(op0, ppc_inst(PPC_RAW_NOP())); > - else > - return ppc_inst_equal(op0, ppc_inst(PPC_RAW_BRANCH(8))) && > - ppc_inst_equal(op1, ppc_inst(PPC_INST_LD_TOC)); > -} > - > -static int > -__ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) > -{ > - ppc_inst_t op[2]; > - void *ip = (void *)rec->ip; > - unsigned long entry, ptr, tramp; > struct module *mod = rec->arch.mod; > - > - /* read where this goes */ > - if (copy_inst_from_kernel_nofault(op, ip)) > - return -EFAULT; > - > - if (!IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) && > - copy_inst_from_kernel_nofault(op + 1, ip + 4)) > - return -EFAULT; > - > - if (!expected_nop_sequence(ip, op[0], op[1])) { > - pr_err("Unexpected call sequence at %p: %08lx %08lx\n", ip, > - ppc_inst_as_ulong(op[0]), ppc_inst_as_ulong(op[1])); > - return -EINVAL; > - } > - > - /* If we never set up ftrace trampoline(s), then bail */ > - if (!mod->arch.tramp || > - (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) && > !mod->arch.tramp_regs)) { > - pr_err("No ftrace trampoline\n"); > - return -EINVAL; > - } > - > - if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) && rec->flags & > FTRACE_FL_REGS) > - tramp = mod->arch.tramp_regs; > - else > - tramp = mod->arch.tramp; > - > - if (module_trampoline_target(mod, tramp, &ptr)) { > - pr_err("Failed to get trampoline target\n"); > - return -EFAULT; > - } > - > - pr_devel("trampoline target %lx", ptr); > - > - entry = ppc_global_function_entry((void *)addr); > - /* This should match what was called */ > - if (ptr != entry) { > - pr_err("addr %lx does not match expected %lx\n", ptr, entry); > - return -EINVAL; > - } > - > - if (patch_branch(ip, tramp, BRANCH_SET_LINK)) { > - pr_err("REL24 out of range!\n"); > - return -EINVAL; > - } > - > - return 0; > -} > -#else > -static int __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) > -{ > - return 0; > -} > -#endif /* CONFIG_MODULES */ > - > -static int __ftrace_make_call_kernel(struct dyn_ftrace *rec, unsigned long > addr) > -{ > - ppc_inst_t op; > - void *ip = (void *)rec->ip; > - unsigned long tramp, entry, ptr; > - > - /* Make sure we're being asked to patch branch to a known ftrace addr > */ > - entry = ppc_global_function_entry((void *)ftrace_caller); > - ptr = ppc_global_function_entry((void *)addr); > - > - if (ptr != entry && IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS)) > - entry = ppc_global_function_entry((void *)ftrace_regs_caller); > - > - if (ptr != entry) { > - pr_err("Unknown ftrace addr to patch: %ps\n", (void *)ptr); > - return -EINVAL; > - } > - > - /* Make sure we have a nop */ > - if (copy_inst_from_kernel_nofault(&op, ip)) { > - pr_err("Unable to read ftrace location %p\n", ip); > - return -EFAULT; > - } > - > - if (!ppc_inst_equal(op, ppc_inst(PPC_RAW_NOP()))) { > - pr_err("Unexpected call sequence at %p: %08lx\n", > - ip, ppc_inst_as_ulong(op)); > - return -EINVAL; > - } > - > - tramp = find_ftrace_tramp((unsigned long)ip); > - if (!tramp) { > - pr_err("No ftrace trampolines reachable from %ps\n", ip); > - return -EINVAL; > - } > - > - if (patch_branch(ip, tramp, BRANCH_SET_LINK)) { > - pr_err("Error patching branch to ftrace tramp!\n"); > - return -EINVAL; > - } > - > - return 0; > -} > - > -int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) > -{ > unsigned long ip = rec->ip; > - ppc_inst_t old, new; > + unsigned long stub; > > - /* > - * 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); > + if (is_offset_in_branch_range(addr - ip)) { > + /* Within range */ > + stub = addr; > } 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 */ > + /* We would be branching to one of our ftrace stubs */ > + stub = find_ftrace_tramp(ip); > + if (!stub) { > + pr_err("0x%lx: No ftrace stubs reachable\n", ip); > + return -EINVAL; > + } > + } else if (IS_ENABLED(CONFIG_MODULES)) { > + /* Module code would be going to one of the module stubs */ > + stub = (addr == (unsigned long)ftrace_caller ? > mod->arch.tramp : mod->arch.tramp_regs); > + } else { > return -EINVAL; > } > > - /* > - * Out of range jumps are called from modules. > - * Being that we are converting from nop, it had better > - * already have a module defined. > - */ > - if (!rec->arch.mod) { > - pr_err("No module loaded\n"); > - return -EINVAL; > - } > - > - return __ftrace_make_call(rec, addr); > + *call_inst = ftrace_create_branch_inst(ip, stub, 1); > + return 0; > } > > #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) > +int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, > unsigned long addr) > { > - ppc_inst_t op; > - unsigned long ip = rec->ip; > - unsigned long entry, ptr, tramp; > - struct module *mod = rec->arch.mod; > + /* This should never be called since we override > ftrace_replace_code() */ > + WARN_ON(1); > + return -EINVAL; > +} > +#endif > > - /* If we never set up ftrace trampolines, then bail */ > - if (!mod->arch.tramp || !mod->arch.tramp_regs) { > - pr_err("No ftrace trampoline\n"); > +int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) > +{ > + ppc_inst_t old, new; > + int ret; > + > + /* This can only ever be called during module load */ > + if (WARN_ON(!IS_ENABLED(CONFIG_MODULES) || core_kernel_text(rec->ip))) > + return -EINVAL; > + > + old = ppc_inst(PPC_RAW_NOP()); > + ret = ftrace_get_call_inst(rec, addr, &new); > + if (ret) > + return ret; > + > + return ftrace_modify_code(rec->ip, old, new); > +} > + > +int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned > long addr) > +{ > + /* > + * This should never be called since we override > ftrace_replace_code(), > + * as well as ftrace_init_nop() > + */ > + WARN_ON(1); > + return -EINVAL; > +} > + > +void ftrace_replace_code(int enable) > +{ > + ppc_inst_t old, new, nop_inst, call_inst, new_call_inst; > + 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); > + update = ftrace_test_record(rec, enable); > + ip = rec->ip; > + new_addr = 0; > + > + switch (update) { > + case FTRACE_UPDATE_IGNORE: > + default: > + continue; > + case FTRACE_UPDATE_MODIFY_CALL: > + addr = ftrace_get_addr_curr(rec); > + new_addr = ftrace_get_addr_new(rec); > + break; > + case FTRACE_UPDATE_MAKE_CALL: > + addr = ftrace_get_addr_new(rec); > + break; > + case FTRACE_UPDATE_MAKE_NOP: > + addr = ftrace_get_addr_curr(rec); > + break; > + } > + nop_inst = ppc_inst(PPC_RAW_NOP()); > + ret = ftrace_get_call_inst(rec, addr, &call_inst); > + if (!ret && new_addr) > + ret = ftrace_get_call_inst(rec, new_addr, > &new_call_inst); > + if (ret) > + goto out; > + > + switch (update) { > + case FTRACE_UPDATE_MODIFY_CALL: > + old = call_inst; > + new = new_call_inst; > + break; > + case FTRACE_UPDATE_MAKE_CALL: > + old = nop_inst; > + new = call_inst; > + break; > + case FTRACE_UPDATE_MAKE_NOP: > + new = nop_inst; > + old = call_inst; > + break; > + } > + > + /* old == new when going to .ftrace.text stub for modify */ > + if (!ppc_inst_equal(old, new)) > + ret = ftrace_modify_code(ip, old, new); > + if (ret) > + goto out; > + ftrace_update_record(rec, enable); > + } > + > +out: > + if (ret) > + ftrace_bug(ret, rec); > + return; > +} > + > +int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) > +{ > + 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 */ > + 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) > + ret = ftrace_validate_inst(ip - 4, > ppc_inst(PPC_RAW_STW(_R0, _R1, 4))); > + } else if (IS_ENABLED(CONFIG_MPROFILE_KERNEL)) { > + /* Expected sequence: 'mflr r0', 'bl _mcount' */ > + ret = ftrace_validate_inst(ip - 4, > ppc_inst(PPC_RAW_MFLR(_R0))); > + } else { > return -EINVAL; > } > > - /* read where this goes */ > - if (copy_inst_from_kernel_nofault(&op, (void *)ip)) { > - pr_err("Fetching opcode failed.\n"); > - return -EFAULT; > - } > + if (ret) > + return ret; > > - /* 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"); > + if (!core_kernel_text(ip)) { > + if (!mod) { > + pr_err("0x%lx: No module provided for non-kernel > address\n", ip); > 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; > - } > + rec->arch.mod = mod; > } > > - /* 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)) { > + /* 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 toolchain-generated stub, or to > the module _mcount > + * stub. Let's just confirm we have a 'bl' here. > */ > - return 0; > - } else if (!IS_ENABLED(CONFIG_MODULES)) { > - /* We should not get here without modules */ > + 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; > } > > - /* > - * 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); > + return ret; > } > -#endif > > int ftrace_update_ftrace_func(ftrace_func_t func) > { > @@ -684,14 +296,14 @@ int ftrace_update_ftrace_func(ftrace_func_t func) > int ret; > > old = ppc_inst_read((u32 *)&ftrace_call); > - new = ftrace_call_replace(ip, (unsigned long)func, 1); > + new = ftrace_create_branch_inst(ip, ppc_function_entry(func), 1); > ret = ftrace_modify_code(ip, old, new); > > /* Also update the regs callback function */ > if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) && !ret) { > ip = (unsigned long)(&ftrace_regs_call); > old = ppc_inst_read((u32 *)&ftrace_regs_call); > - new = ftrace_call_replace(ip, (unsigned long)func, 1); > + new = ftrace_create_branch_inst(ip, ppc_function_entry(func), > 1); > ret = ftrace_modify_code(ip, old, new); > } > > @@ -723,6 +335,17 @@ void ftrace_free_init_tramp(void) > } > } > > +static void __init add_ftrace_tramp(unsigned long tramp) > +{ > + int i; > + > + for (i = 0; i < NUM_FTRACE_TRAMPS; i++) > + if (!ftrace_tramps[i]) { > + ftrace_tramps[i] = tramp; > + return; > + } > +} > + > int __init ftrace_dyn_arch_init(void) > { > int i; > @@ -745,14 +368,9 @@ int __init ftrace_dyn_arch_init(void) > }; > #endif > > - unsigned long addr; > + unsigned long addr = FTRACE_REGS_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); > - > if (IS_ENABLED(CONFIG_PPC_KERNEL_PCREL)) { > for (i = 0; i < 2; i++) { > reladdr = addr - (unsigned long)tramp[i]; > @@ -804,8 +422,8 @@ static int ftrace_modify_ftrace_graph_caller(bool enable) > 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); > + old = ftrace_create_branch_inst(ip, enable ? stub : addr, 0); > + new = ftrace_create_branch_inst(ip, enable ? addr : stub, 0); > > return ftrace_modify_code(ip, old, new); > } > @@ -864,13 +482,3 @@ unsigned long prepare_ftrace_return(unsigned long > parent, unsigned long ip, > } > #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_pg.c > b/arch/powerpc/kernel/trace/ftrace_pg.c > new file mode 100644 > index 00000000000000..7b85c3b460a3c0 > --- /dev/null > +++ b/arch/powerpc/kernel/trace/ftrace_pg.c > @@ -0,0 +1,846 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Code for replacing ftrace calls with jumps. > + * > + * Copyright (C) 2007-2008 Steven Rostedt <srost...@redhat.com> > + * > + * Thanks goes out to P.A. Semi, Inc for supplying me with a PPC64 box. > + * > + * Added function graph tracer code, taken from x86 that was written > + * by Frederic Weisbecker, and ported to PPC by Steven Rostedt. > + * > + */ > + > +#define pr_fmt(fmt) "ftrace-powerpc: " fmt > + > +#include <linux/spinlock.h> > +#include <linux/hardirq.h> > +#include <linux/uaccess.h> > +#include <linux/module.h> > +#include <linux/ftrace.h> > +#include <linux/percpu.h> > +#include <linux/init.h> > +#include <linux/list.h> > + > +#include <asm/cacheflush.h> > +#include <asm/code-patching.h> > +#include <asm/ftrace.h> > +#include <asm/syscall.h> > +#include <asm/inst.h> > + > +/* > + * We generally only have a single long_branch tramp and at most 2 or 3 plt > + * tramps generated. But, we don't use the plt tramps currently. We also > allot > + * 2 tramps after .text and .init.text. So, we only end up with around 3 > usable > + * tramps in total. Set aside 8 just to be sure. > + */ > +#define NUM_FTRACE_TRAMPS 8 > +static unsigned long ftrace_tramps[NUM_FTRACE_TRAMPS]; > + > +static ppc_inst_t > +ftrace_call_replace(unsigned long ip, unsigned long addr, int link) > +{ > + ppc_inst_t op; > + > + addr = ppc_function_entry((void *)addr); > + > + /* if (link) set op to 'bl' else 'b' */ > + create_branch(&op, (u32 *)ip, addr, link ? BRANCH_SET_LINK : 0); > + > + return op; > +} > + > +static inline int > +ftrace_modify_code(unsigned long ip, ppc_inst_t old, ppc_inst_t new) > +{ > + ppc_inst_t replaced; > + > + /* > + * Note: > + * We are paranoid about modifying text, as if a bug was to happen, it > + * could cause us to read or write to someplace that could cause harm. > + * Carefully read and modify the code with probe_kernel_*(), and make > + * sure what we read is what we expected it to be before modifying it. > + */ > + > + /* read the text we want to modify */ > + if (copy_inst_from_kernel_nofault(&replaced, (void *)ip)) > + return -EFAULT; > + > + /* Make sure it is what we expect it to be */ > + if (!ppc_inst_equal(replaced, old)) { > + pr_err("%p: replaced (%08lx) != old (%08lx)", (void *)ip, > + ppc_inst_as_ulong(replaced), ppc_inst_as_ulong(old)); > + return -EINVAL; > + } > + > + /* replace the text with the new text */ > + return patch_instruction((u32 *)ip, new); > +} > + > +/* > + * Helper functions that are the same for both PPC64 and PPC32. > + */ > +static int test_24bit_addr(unsigned long ip, unsigned long addr) > +{ > + addr = ppc_function_entry((void *)addr); > + > + return is_offset_in_branch_range(addr - ip); > +} > + > +static int is_bl_op(ppc_inst_t op) > +{ > + return (ppc_inst_val(op) & ~PPC_LI_MASK) == PPC_RAW_BL(0); > +} > + > +static int is_b_op(ppc_inst_t op) > +{ > + return (ppc_inst_val(op) & ~PPC_LI_MASK) == PPC_RAW_BRANCH(0); > +} > + > +static unsigned long find_bl_target(unsigned long ip, ppc_inst_t op) > +{ > + int offset; > + > + offset = PPC_LI(ppc_inst_val(op)); > + /* make it signed */ > + if (offset & 0x02000000) > + offset |= 0xfe000000; > + > + return ip + (long)offset; > +} > + > +#ifdef CONFIG_MODULES > +static int > +__ftrace_make_nop(struct module *mod, > + struct dyn_ftrace *rec, unsigned long addr) > +{ > + unsigned long entry, ptr, tramp; > + unsigned long ip = rec->ip; > + ppc_inst_t op, pop; > + > + /* read where this goes */ > + if (copy_inst_from_kernel_nofault(&op, (void *)ip)) { > + pr_err("Fetching opcode failed.\n"); > + return -EFAULT; > + } > + > + /* Make sure that this is still a 24bit jump */ > + if (!is_bl_op(op)) { > + pr_err("Not expected bl: opcode is %08lx\n", > ppc_inst_as_ulong(op)); > + return -EINVAL; > + } > + > + /* lets find where the pointer goes */ > + tramp = find_bl_target(ip, op); > + > + pr_devel("ip:%lx jumps to %lx", ip, tramp); > + > + if (module_trampoline_target(mod, tramp, &ptr)) { > + pr_err("Failed to get trampoline target\n"); > + return -EFAULT; > + } > + > + pr_devel("trampoline target %lx", ptr); > + > + entry = ppc_global_function_entry((void *)addr); > + /* This should match what was called */ > + if (ptr != entry) { > + pr_err("addr %lx does not match expected %lx\n", ptr, entry); > + return -EINVAL; > + } > + > + if (IS_ENABLED(CONFIG_MPROFILE_KERNEL)) { > + if (copy_inst_from_kernel_nofault(&op, (void *)(ip - 4))) { > + pr_err("Fetching instruction at %lx failed.\n", ip - > 4); > + return -EFAULT; > + } > + > + /* We expect either a mflr r0, or a std r0, LRSAVE(r1) */ > + if (!ppc_inst_equal(op, ppc_inst(PPC_RAW_MFLR(_R0))) && > + !ppc_inst_equal(op, ppc_inst(PPC_INST_STD_LR))) { > + pr_err("Unexpected instruction %08lx around bl > _mcount\n", > + ppc_inst_as_ulong(op)); > + return -EINVAL; > + } > + } else if (IS_ENABLED(CONFIG_PPC64)) { > + /* > + * Check what is in the next instruction. We can see ld > r2,40(r1), but > + * on first pass after boot we will see mflr r0. > + */ > + if (copy_inst_from_kernel_nofault(&op, (void *)(ip + 4))) { > + pr_err("Fetching op failed.\n"); > + return -EFAULT; > + } > + > + if (!ppc_inst_equal(op, ppc_inst(PPC_INST_LD_TOC))) { > + pr_err("Expected %08lx found %08lx\n", > PPC_INST_LD_TOC, > + ppc_inst_as_ulong(op)); > + return -EINVAL; > + } > + } > + > + /* > + * When using -mprofile-kernel or PPC32 there is no load to jump over. > + * > + * Otherwise our original call site looks like: > + * > + * bl <tramp> > + * ld r2,XX(r1) > + * > + * Milton Miller pointed out that we can not simply nop the branch. > + * If a task was preempted when calling a trace function, the nops > + * will remove the way to restore the TOC in r2 and the r2 TOC will > + * get corrupted. > + * > + * Use a b +8 to jump over the load. > + */ > + if (IS_ENABLED(CONFIG_MPROFILE_KERNEL) || IS_ENABLED(CONFIG_PPC32)) > + pop = ppc_inst(PPC_RAW_NOP()); > + else > + pop = ppc_inst(PPC_RAW_BRANCH(8)); /* b +8 */ > + > + if (patch_instruction((u32 *)ip, pop)) { > + pr_err("Patching NOP failed.\n"); > + return -EPERM; > + } > + > + return 0; > +} > +#else > +static int __ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, > unsigned long addr) > +{ > + return 0; > +} > +#endif /* CONFIG_MODULES */ > + > +static unsigned long find_ftrace_tramp(unsigned long ip) > +{ > + int i; > + > + /* > + * We have the compiler generated long_branch tramps at the end > + * and we prefer those > + */ > + for (i = NUM_FTRACE_TRAMPS - 1; i >= 0; i--) > + if (!ftrace_tramps[i]) > + continue; > + else if (is_offset_in_branch_range(ftrace_tramps[i] - ip)) > + return ftrace_tramps[i]; > + > + return 0; > +} > + > +static int add_ftrace_tramp(unsigned long tramp) > +{ > + int i; > + > + for (i = 0; i < NUM_FTRACE_TRAMPS; i++) > + if (!ftrace_tramps[i]) { > + ftrace_tramps[i] = tramp; > + return 0; > + } > + > + return -1; > +} > + > +/* > + * If this is a compiler generated long_branch trampoline (essentially, a > + * trampoline that has a branch to _mcount()), we re-write the branch to > + * instead go to ftrace_[regs_]caller() and note down the location of this > + * trampoline. > + */ > +static int setup_mcount_compiler_tramp(unsigned long tramp) > +{ > + int i; > + ppc_inst_t op; > + unsigned long ptr; > + > + /* Is this a known long jump tramp? */ > + for (i = 0; i < NUM_FTRACE_TRAMPS; i++) > + if (ftrace_tramps[i] == tramp) > + return 0; > + > + /* New trampoline -- read where this goes */ > + if (copy_inst_from_kernel_nofault(&op, (void *)tramp)) { > + pr_debug("Fetching opcode failed.\n"); > + return -1; > + } > + > + /* Is this a 24 bit branch? */ > + if (!is_b_op(op)) { > + pr_debug("Trampoline is not a long branch tramp.\n"); > + return -1; > + } > + > + /* lets find where the pointer goes */ > + ptr = find_bl_target(tramp, op); > + > + if (ptr != ppc_global_function_entry((void *)_mcount)) { > + pr_debug("Trampoline target %p is not _mcount\n", (void > *)ptr); > + return -1; > + } > + > + /* Let's re-write the tramp to go to ftrace_[regs_]caller */ > + if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS)) > + ptr = ppc_global_function_entry((void *)ftrace_regs_caller); > + else > + ptr = ppc_global_function_entry((void *)ftrace_caller); > + > + if (patch_branch((u32 *)tramp, ptr, 0)) { > + pr_debug("REL24 out of range!\n"); > + return -1; > + } > + > + if (add_ftrace_tramp(tramp)) { > + pr_debug("No tramp locations left\n"); > + return -1; > + } > + > + return 0; > +} > + > +static int __ftrace_make_nop_kernel(struct dyn_ftrace *rec, unsigned long > addr) > +{ > + unsigned long tramp, ip = rec->ip; > + ppc_inst_t op; > + > + /* Read where this goes */ > + if (copy_inst_from_kernel_nofault(&op, (void *)ip)) { > + pr_err("Fetching opcode failed.\n"); > + return -EFAULT; > + } > + > + /* Make sure that this is still a 24bit jump */ > + if (!is_bl_op(op)) { > + pr_err("Not expected bl: opcode is %08lx\n", > ppc_inst_as_ulong(op)); > + return -EINVAL; > + } > + > + /* Let's find where the pointer goes */ > + tramp = find_bl_target(ip, op); > + > + pr_devel("ip:%lx jumps to %lx", ip, tramp); > + > + if (setup_mcount_compiler_tramp(tramp)) { > + /* Are other trampolines reachable? */ > + if (!find_ftrace_tramp(ip)) { > + pr_err("No ftrace trampolines reachable from %ps\n", > + (void *)ip); > + return -EINVAL; > + } > + } > + > + if (patch_instruction((u32 *)ip, ppc_inst(PPC_RAW_NOP()))) { > + pr_err("Patching NOP failed.\n"); > + return -EPERM; > + } > + > + return 0; > +} > + > +int ftrace_make_nop(struct module *mod, > + struct dyn_ftrace *rec, unsigned long addr) > +{ > + unsigned long ip = rec->ip; > + ppc_inst_t old, new; > + > + /* > + * If the calling address is more that 24 bits away, > + * then we had to use a trampoline to make the call. > + * Otherwise just update the call site. > + */ > + if (test_24bit_addr(ip, addr)) { > + /* within range */ > + old = ftrace_call_replace(ip, addr, 1); > + new = ppc_inst(PPC_RAW_NOP()); > + return ftrace_modify_code(ip, old, new); > + } else if (core_kernel_text(ip)) { > + return __ftrace_make_nop_kernel(rec, addr); > + } else if (!IS_ENABLED(CONFIG_MODULES)) { > + return -EINVAL; > + } > + > + /* > + * Out of range jumps are called from modules. > + * We should either already have a pointer to the module > + * or it has been passed in. > + */ > + if (!rec->arch.mod) { > + if (!mod) { > + pr_err("No module loaded addr=%lx\n", addr); > + return -EFAULT; > + } > + rec->arch.mod = mod; > + } else if (mod) { > + if (mod != rec->arch.mod) { > + pr_err("Record mod %p not equal to passed in mod > %p\n", > + rec->arch.mod, mod); > + return -EINVAL; > + } > + /* nothing to do if mod == rec->arch.mod */ > + } else > + mod = rec->arch.mod; > + > + return __ftrace_make_nop(mod, rec, addr); > +} > + > +#ifdef CONFIG_MODULES > +/* > + * Examine the existing instructions for __ftrace_make_call. > + * They should effectively be a NOP, and follow formal constraints, > + * depending on the ABI. Return false if they don't. > + */ > +static bool expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1) > +{ > + if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS)) > + return ppc_inst_equal(op0, ppc_inst(PPC_RAW_NOP())); > + else > + return ppc_inst_equal(op0, ppc_inst(PPC_RAW_BRANCH(8))) && > + ppc_inst_equal(op1, ppc_inst(PPC_INST_LD_TOC)); > +} > + > +static int > +__ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) > +{ > + ppc_inst_t op[2]; > + void *ip = (void *)rec->ip; > + unsigned long entry, ptr, tramp; > + struct module *mod = rec->arch.mod; > + > + /* read where this goes */ > + if (copy_inst_from_kernel_nofault(op, ip)) > + return -EFAULT; > + > + if (!IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) && > + copy_inst_from_kernel_nofault(op + 1, ip + 4)) > + return -EFAULT; > + > + if (!expected_nop_sequence(ip, op[0], op[1])) { > + pr_err("Unexpected call sequence at %p: %08lx %08lx\n", ip, > + ppc_inst_as_ulong(op[0]), ppc_inst_as_ulong(op[1])); > + return -EINVAL; > + } > + > + /* If we never set up ftrace trampoline(s), then bail */ > + if (!mod->arch.tramp || > + (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) && > !mod->arch.tramp_regs)) { > + pr_err("No ftrace trampoline\n"); > + return -EINVAL; > + } > + > + if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) && rec->flags & > FTRACE_FL_REGS) > + tramp = mod->arch.tramp_regs; > + else > + tramp = mod->arch.tramp; > + > + if (module_trampoline_target(mod, tramp, &ptr)) { > + pr_err("Failed to get trampoline target\n"); > + return -EFAULT; > + } > + > + pr_devel("trampoline target %lx", ptr); > + > + entry = ppc_global_function_entry((void *)addr); > + /* This should match what was called */ > + if (ptr != entry) { > + pr_err("addr %lx does not match expected %lx\n", ptr, entry); > + return -EINVAL; > + } > + > + if (patch_branch(ip, tramp, BRANCH_SET_LINK)) { > + pr_err("REL24 out of range!\n"); > + return -EINVAL; > + } > + > + return 0; > +} > +#else > +static int __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) > +{ > + return 0; > +} > +#endif /* CONFIG_MODULES */ > + > +static int __ftrace_make_call_kernel(struct dyn_ftrace *rec, unsigned long > addr) > +{ > + ppc_inst_t op; > + void *ip = (void *)rec->ip; > + unsigned long tramp, entry, ptr; > + > + /* Make sure we're being asked to patch branch to a known ftrace addr > */ > + entry = ppc_global_function_entry((void *)ftrace_caller); > + ptr = ppc_global_function_entry((void *)addr); > + > + if (ptr != entry && IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS)) > + entry = ppc_global_function_entry((void *)ftrace_regs_caller); > + > + if (ptr != entry) { > + pr_err("Unknown ftrace addr to patch: %ps\n", (void *)ptr); > + return -EINVAL; > + } > + > + /* Make sure we have a nop */ > + if (copy_inst_from_kernel_nofault(&op, ip)) { > + pr_err("Unable to read ftrace location %p\n", ip); > + return -EFAULT; > + } > + > + if (!ppc_inst_equal(op, ppc_inst(PPC_RAW_NOP()))) { > + pr_err("Unexpected call sequence at %p: %08lx\n", > + ip, ppc_inst_as_ulong(op)); > + return -EINVAL; > + } > + > + tramp = find_ftrace_tramp((unsigned long)ip); > + if (!tramp) { > + pr_err("No ftrace trampolines reachable from %ps\n", ip); > + return -EINVAL; > + } > + > + if (patch_branch(ip, tramp, BRANCH_SET_LINK)) { > + pr_err("Error patching branch to ftrace tramp!\n"); > + return -EINVAL; > + } > + > + return 0; > +} > + > +int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) > +{ > + unsigned long ip = rec->ip; > + ppc_inst_t old, new; > + > + /* > + * If the calling address is more that 24 bits away, > + * then we had to use a trampoline to make the call. > + * Otherwise just update the call site. > + */ > + if (test_24bit_addr(ip, addr)) { > + /* within range */ > + old = ppc_inst(PPC_RAW_NOP()); > + new = ftrace_call_replace(ip, addr, 1); > + return ftrace_modify_code(ip, old, new); > + } else if (core_kernel_text(ip)) { > + return __ftrace_make_call_kernel(rec, addr); > + } else if (!IS_ENABLED(CONFIG_MODULES)) { > + /* We should not get here without modules */ > + return -EINVAL; > + } > + > + /* > + * Out of range jumps are called from modules. > + * Being that we are converting from nop, it had better > + * already have a module defined. > + */ > + if (!rec->arch.mod) { > + pr_err("No module loaded\n"); > + return -EINVAL; > + } > + > + return __ftrace_make_call(rec, addr); > +} > + > +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS > +#ifdef CONFIG_MODULES > +static int > +__ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, > + unsigned long addr) > +{ > + ppc_inst_t op; > + unsigned long ip = rec->ip; > + unsigned long entry, ptr, tramp; > + struct module *mod = rec->arch.mod; > + > + /* If we never set up ftrace trampolines, then bail */ > + if (!mod->arch.tramp || !mod->arch.tramp_regs) { > + pr_err("No ftrace trampoline\n"); > + return -EINVAL; > + } > + > + /* read where this goes */ > + if (copy_inst_from_kernel_nofault(&op, (void *)ip)) { > + pr_err("Fetching opcode failed.\n"); > + return -EFAULT; > + } > + > + /* Make sure that this is still a 24bit jump */ > + if (!is_bl_op(op)) { > + pr_err("Not expected bl: opcode is %08lx\n", > ppc_inst_as_ulong(op)); > + return -EINVAL; > + } > + > + /* lets find where the pointer goes */ > + tramp = find_bl_target(ip, op); > + entry = ppc_global_function_entry((void *)old_addr); > + > + pr_devel("ip:%lx jumps to %lx", ip, tramp); > + > + if (tramp != entry) { > + /* old_addr is not within range, so we must have used a > trampoline */ > + if (module_trampoline_target(mod, tramp, &ptr)) { > + pr_err("Failed to get trampoline target\n"); > + return -EFAULT; > + } > + > + pr_devel("trampoline target %lx", ptr); > + > + /* This should match what was called */ > + if (ptr != entry) { > + pr_err("addr %lx does not match expected %lx\n", ptr, > entry); > + return -EINVAL; > + } > + } > + > + /* The new target may be within range */ > + if (test_24bit_addr(ip, addr)) { > + /* within range */ > + if (patch_branch((u32 *)ip, addr, BRANCH_SET_LINK)) { > + pr_err("REL24 out of range!\n"); > + return -EINVAL; > + } > + > + return 0; > + } > + > + if (rec->flags & FTRACE_FL_REGS) > + tramp = mod->arch.tramp_regs; > + else > + tramp = mod->arch.tramp; > + > + if (module_trampoline_target(mod, tramp, &ptr)) { > + pr_err("Failed to get trampoline target\n"); > + return -EFAULT; > + } > + > + pr_devel("trampoline target %lx", ptr); > + > + entry = ppc_global_function_entry((void *)addr); > + /* This should match what was called */ > + if (ptr != entry) { > + pr_err("addr %lx does not match expected %lx\n", ptr, entry); > + return -EINVAL; > + } > + > + if (patch_branch((u32 *)ip, tramp, BRANCH_SET_LINK)) { > + pr_err("REL24 out of range!\n"); > + return -EINVAL; > + } > + > + return 0; > +} > +#else > +static int __ftrace_modify_call(struct dyn_ftrace *rec, unsigned long > old_addr, unsigned long addr) > +{ > + return 0; > +} > +#endif > + > +int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, > + unsigned long addr) > +{ > + unsigned long ip = rec->ip; > + ppc_inst_t old, new; > + > + /* > + * If the calling address is more that 24 bits away, > + * then we had to use a trampoline to make the call. > + * Otherwise just update the call site. > + */ > + if (test_24bit_addr(ip, addr) && test_24bit_addr(ip, old_addr)) { > + /* within range */ > + old = ftrace_call_replace(ip, old_addr, 1); > + new = ftrace_call_replace(ip, addr, 1); > + return ftrace_modify_code(ip, old, new); > + } else if (core_kernel_text(ip)) { > + /* > + * We always patch out of range locations to go to the regs > + * variant, so there is nothing to do here > + */ > + return 0; > + } else if (!IS_ENABLED(CONFIG_MODULES)) { > + /* We should not get here without modules */ > + return -EINVAL; > + } > + > + /* > + * Out of range jumps are called from modules. > + */ > + if (!rec->arch.mod) { > + pr_err("No module loaded\n"); > + return -EINVAL; > + } > + > + return __ftrace_modify_call(rec, old_addr, addr); > +} > +#endif > + > +int ftrace_update_ftrace_func(ftrace_func_t func) > +{ > + unsigned long ip = (unsigned long)(&ftrace_call); > + ppc_inst_t old, new; > + int ret; > + > + old = ppc_inst_read((u32 *)&ftrace_call); > + new = ftrace_call_replace(ip, (unsigned long)func, 1); > + ret = ftrace_modify_code(ip, old, new); > + > + /* Also update the regs callback function */ > + if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) && !ret) { > + ip = (unsigned long)(&ftrace_regs_call); > + old = ppc_inst_read((u32 *)&ftrace_regs_call); > + new = ftrace_call_replace(ip, (unsigned long)func, 1); > + ret = ftrace_modify_code(ip, old, new); > + } > + > + return ret; > +} > + > +/* > + * Use the default ftrace_modify_all_code, but without > + * stop_machine(). > + */ > +void arch_ftrace_update_code(int command) > +{ > + ftrace_modify_all_code(command); > +} > + > +#ifdef CONFIG_PPC64 > +#define PACATOC offsetof(struct paca_struct, kernel_toc) > + > +extern unsigned int ftrace_tramp_text[], ftrace_tramp_init[]; > + > +void ftrace_free_init_tramp(void) > +{ > + int i; > + > + for (i = 0; i < NUM_FTRACE_TRAMPS && ftrace_tramps[i]; i++) > + if (ftrace_tramps[i] == (unsigned long)ftrace_tramp_init) { > + ftrace_tramps[i] = 0; > + return; > + } > +} > + > +int __init ftrace_dyn_arch_init(void) > +{ > + int i; > + unsigned int *tramp[] = { ftrace_tramp_text, ftrace_tramp_init }; > + u32 stub_insns[] = { > + PPC_RAW_LD(_R12, _R13, PACATOC), > + PPC_RAW_ADDIS(_R12, _R12, 0), > + PPC_RAW_ADDI(_R12, _R12, 0), > + PPC_RAW_MTCTR(_R12), > + PPC_RAW_BCTR() > + }; > + unsigned long addr; > + long reladdr; > + > + if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS)) > + addr = ppc_global_function_entry((void *)ftrace_regs_caller); > + else > + addr = ppc_global_function_entry((void *)ftrace_caller); > + > + reladdr = addr - kernel_toc_addr(); > + > + if (reladdr >= SZ_2G || reladdr < -(long)SZ_2G) { > + pr_err("Address of %ps out of range of kernel_toc.\n", > + (void *)addr); > + return -1; > + } > + > + for (i = 0; i < 2; i++) { > + memcpy(tramp[i], stub_insns, sizeof(stub_insns)); > + tramp[i][1] |= PPC_HA(reladdr); > + tramp[i][2] |= PPC_LO(reladdr); > + add_ftrace_tramp((unsigned long)tramp[i]); > + } > + > + return 0; > +} > +#endif > + > +#ifdef CONFIG_FUNCTION_GRAPH_TRACER > + > +extern void ftrace_graph_call(void); > +extern void ftrace_graph_stub(void); > + > +static int ftrace_modify_ftrace_graph_caller(bool enable) > +{ > + unsigned long ip = (unsigned long)(&ftrace_graph_call); > + unsigned long addr = (unsigned long)(&ftrace_graph_caller); > + unsigned long stub = (unsigned long)(&ftrace_graph_stub); > + ppc_inst_t old, new; > + > + if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_ARGS)) > + return 0; > + > + old = ftrace_call_replace(ip, enable ? stub : addr, 0); > + new = ftrace_call_replace(ip, enable ? addr : stub, 0); > + > + return ftrace_modify_code(ip, old, new); > +} > + > +int ftrace_enable_ftrace_graph_caller(void) > +{ > + return ftrace_modify_ftrace_graph_caller(true); > +} > + > +int ftrace_disable_ftrace_graph_caller(void) > +{ > + return ftrace_modify_ftrace_graph_caller(false); > +} > + > +/* > + * Hook the return address and push it in the stack of return addrs > + * in current thread info. Return the address we want to divert to. > + */ > +static unsigned long > +__prepare_ftrace_return(unsigned long parent, unsigned long ip, unsigned > long sp) > +{ > + unsigned long return_hooker; > + int bit; > + > + if (unlikely(ftrace_graph_is_dead())) > + goto out; > + > + if (unlikely(atomic_read(¤t->tracing_graph_pause))) > + goto out; > + > + bit = ftrace_test_recursion_trylock(ip, parent); > + if (bit < 0) > + goto out; > + > + return_hooker = ppc_function_entry(return_to_handler); > + > + if (!function_graph_enter(parent, ip, 0, (unsigned long *)sp)) > + parent = return_hooker; > + > + ftrace_test_recursion_unlock(bit); > +out: > + return parent; > +} > + > +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS > +void ftrace_graph_func(unsigned long ip, unsigned long parent_ip, > + struct ftrace_ops *op, struct ftrace_regs *fregs) > +{ > + fregs->regs.link = __prepare_ftrace_return(parent_ip, ip, > fregs->regs.gpr[1]); > +} > +#else > +unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip, > + unsigned long sp) > +{ > + return __prepare_ftrace_return(parent, ip, sp); > +} > +#endif > +#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ > + > +#ifdef CONFIG_PPC64_ELF_ABI_V1 > +char *arch_ftrace_match_adjust(char *str, const char *search) > +{ > + if (str[0] == '.' && search[0] != '.') > + return str + 1; > + else > + return str; > +} > +#endif /* CONFIG_PPC64_ELF_ABI_V1 */ > diff --git a/arch/powerpc/tools/gcc-check-fpatchable-function-entry.sh > b/arch/powerpc/tools/gcc-check-fpatchable-function-entry.sh > new file mode 100755 > index 00000000000000..410e349cc48428 > --- /dev/null > +++ b/arch/powerpc/tools/gcc-check-fpatchable-function-entry.sh > @@ -0,0 +1,20 @@ > +#!/bin/bash > +# SPDX-License-Identifier: GPL-2.0 > + > +set -e > +set -o pipefail > + > +# To debug, uncomment the following line > +# set -x > + > +# Output from -fpatchable-function-entry can only vary on 64le, so this > should > +# not be invoked for other targets. Therefore we can pass in -m64 and -mabi > +# explicitly, to take care of toolchains defaulting to other targets. > + > +# Test whether the nops are generated before the global entry point. > +echo "int x; int func() { return x; }" | \ > + $* -m64 -mabi=elfv2 -S -x c -O2 -fpatchable-function-entry=2,2 - -o - 2> > /dev/null | \ > + awk 'BEGIN { RS = ";" } /nop\n[[:space:]]*nop\n.*\nfunc:/ { print $0 }' > | \ > + grep -q "func:" || exit 0 > + > +exit 1 > > base-commit: 6d40746dbb75f85a18a0df005f1a8d6147abec22 > prerequisite-patch-id: 3862cf6dc646260228e50b70c316cf15b1d7f384 > prerequisite-patch-id: 859f60071f4e425c806fc7fe6c59e268232050a4 > prerequisite-patch-id: ef23f712e50f106d689a550dae0f816285c1db3b > prerequisite-patch-id: 8c6d31bb6ac4e4bef086fe502efa660ae99a96ca > -- > 2.40.1 >