diff options
| -rw-r--r-- | arch/powerpc/Kconfig | 14 | ||||
| -rw-r--r-- | arch/powerpc/Makefile | 5 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/ftrace.h | 6 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/vermagic.h | 4 | ||||
| -rw-r--r-- | arch/powerpc/kernel/module_64.c | 2 | ||||
| -rw-r--r-- | arch/powerpc/kernel/trace/ftrace.c | 14 | ||||
| -rw-r--r-- | arch/powerpc/kernel/trace/ftrace_entry.S | 2 | ||||
| -rwxr-xr-x | arch/powerpc/tools/gcc-check-fpatchable-function-entry.sh | 26 |
8 files changed, 64 insertions, 9 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index cb0a89946c4e..c831e20cf40f 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -186,6 +186,7 @@ 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 @@ -227,8 +228,8 @@ config PPC select HAVE_DEBUG_KMEMLEAK select HAVE_DEBUG_STACKOVERFLOW select HAVE_DYNAMIC_FTRACE - select HAVE_DYNAMIC_FTRACE_WITH_ARGS if MPROFILE_KERNEL || PPC32 - select HAVE_DYNAMIC_FTRACE_WITH_REGS if MPROFILE_KERNEL || PPC32 + select HAVE_DYNAMIC_FTRACE_WITH_ARGS if ARCH_USING_PATCHABLE_FUNCTION_ENTRY || MPROFILE_KERNEL || PPC32 + select HAVE_DYNAMIC_FTRACE_WITH_REGS if ARCH_USING_PATCHABLE_FUNCTION_ENTRY || MPROFILE_KERNEL || PPC32 select HAVE_EBPF_JIT select HAVE_EFFICIENT_UNALIGNED_ACCESS select HAVE_FAST_GUP @@ -256,7 +257,7 @@ config PPC select HAVE_MOD_ARCH_SPECIFIC select HAVE_NMI if PERF_EVENTS || (PPC64 && PPC_BOOK3S) select HAVE_OPTPROBES - select HAVE_OBJTOOL if PPC32 || MPROFILE_KERNEL + select HAVE_OBJTOOL if ARCH_USING_PATCHABLE_FUNCTION_ENTRY || MPROFILE_KERNEL || PPC32 select HAVE_OBJTOOL_MCOUNT if HAVE_OBJTOOL select HAVE_PERF_EVENTS select HAVE_PERF_EVENTS_NMI if PPC64 @@ -554,6 +555,13 @@ 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_USING_PATCHABLE_FUNCTION_ENTRY + depends on FUNCTION_TRACER && (PPC32 || PPC64_ELF_ABI_V2) + depends on $(cc-option,-fpatchable-function-entry=2) + def_bool y if PPC32 + def_bool $(success,$(srctree)/arch/powerpc/tools/gcc-check-fpatchable-function-entry.sh $(CC) -mlittle-endian) if PPC64 && CPU_LITTLE_ENDIAN + def_bool $(success,$(srctree)/arch/powerpc/tools/gcc-check-fpatchable-function-entry.sh $(CC) -mbig-endian) if PPC64 && CPU_BIG_ENDIAN + config HOTPLUG_CPU bool "Support for enabling/disabling CPUs" depends on SMP && (PPC_PSERIES || \ diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index dac7ca153886..cbd34459cce0 100644 --- a/arch/powerpc/Makefile +++ b/arch/powerpc/Makefile @@ -143,11 +143,16 @@ CFLAGS-$(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 ef9f0b97670d..9e5a39b6a311 100644 --- a/arch/powerpc/include/asm/ftrace.h +++ b/arch/powerpc/include/asm/ftrace.h @@ -11,7 +11,7 @@ #define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR /* Ignore unused weak functions which will have larger offsets */ -#ifdef CONFIG_MPROFILE_KERNEL +#if defined(CONFIG_MPROFILE_KERNEL) || defined(CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY) #define FTRACE_MCOUNT_MAX_OFFSET 16 #elif defined(CONFIG_PPC32) #define FTRACE_MCOUNT_MAX_OFFSET 8 @@ -22,7 +22,9 @@ 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; } diff --git a/arch/powerpc/include/asm/vermagic.h b/arch/powerpc/include/asm/vermagic.h index b054a8576e5d..6f250fe506bd 100644 --- a/arch/powerpc/include/asm/vermagic.h +++ b/arch/powerpc/include/asm/vermagic.h @@ -2,7 +2,9 @@ #ifndef _ASM_VERMAGIC_H #define _ASM_VERMAGIC_H -#ifdef CONFIG_MPROFILE_KERNEL +#ifdef CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY +#define MODULE_ARCH_VERMAGIC_FTRACE "patchable-function-entry " +#elif defined(CONFIG_MPROFILE_KERNEL) #define MODULE_ARCH_VERMAGIC_FTRACE "mprofile-kernel " #else #define MODULE_ARCH_VERMAGIC_FTRACE "" diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c index 92570289ce08..7112adc597a8 100644 --- a/arch/powerpc/kernel/module_64.c +++ b/arch/powerpc/kernel/module_64.c @@ -465,7 +465,7 @@ int module_frob_arch_sections(Elf64_Ehdr *hdr, return 0; } -#ifdef CONFIG_MPROFILE_KERNEL +#if defined(CONFIG_MPROFILE_KERNEL) || defined(CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY) static u32 stub_insns[] = { #ifdef CONFIG_PPC_KERNEL_PCREL diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c index cf9dce775279..82010629cf88 100644 --- a/arch/powerpc/kernel/trace/ftrace.c +++ b/arch/powerpc/kernel/trace/ftrace.c @@ -220,7 +220,12 @@ int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) int ret = 0; /* Verify instructions surrounding the ftrace location */ - if (IS_ENABLED(CONFIG_PPC32)) { + 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) @@ -250,7 +255,12 @@ int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) /* Nop-out the ftrace location */ new = ppc_inst(PPC_RAW_NOP()); addr = MCOUNT_ADDR; - if (is_offset_in_branch_range(addr - ip)) { + 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); diff --git a/arch/powerpc/kernel/trace/ftrace_entry.S b/arch/powerpc/kernel/trace/ftrace_entry.S index 4e7103c316fb..0b3d77d65a79 100644 --- a/arch/powerpc/kernel/trace/ftrace_entry.S +++ b/arch/powerpc/kernel/trace/ftrace_entry.S @@ -250,6 +250,7 @@ livepatch_handler: blr #endif /* CONFIG_LIVEPATCH */ +#ifndef CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY _GLOBAL(mcount) _GLOBAL(_mcount) EXPORT_SYMBOL(_mcount) @@ -257,6 +258,7 @@ EXPORT_SYMBOL(_mcount) mtctr r12 mtlr r0 bctr +#endif #ifdef CONFIG_FUNCTION_GRAPH_TRACER _GLOBAL(return_to_handler) 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 000000000000..06706903503b --- /dev/null +++ b/arch/powerpc/tools/gcc-check-fpatchable-function-entry.sh @@ -0,0 +1,26 @@ +#!/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 ppc64 elfv2, 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 compile option -fpatchable-function-entry exists and +# generates appropriate code +echo "int func() { return 0; }" | \ + $* -m64 -mabi=elfv2 -S -x c -O2 -fpatchable-function-entry=2 - -o - 2> /dev/null | \ + grep -q "__patchable_function_entries" + +# Test whether nops are generated after the local entry point +echo "int x; int func() { return x; }" | \ + $* -m64 -mabi=elfv2 -S -x c -O2 -fpatchable-function-entry=2 - -o - 2> /dev/null | \ + awk 'BEGIN { RS = ";" } /\.localentry.*nop.*\n[[:space:]]*nop/ { print $0 }' | \ + grep -q "func:" + +exit 0 |