diff options
25 files changed, 778 insertions, 140 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 832cc461d0af..944a79a2768f 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -94,6 +94,7 @@ config PPC select OF_RESERVED_MEM select HAVE_FTRACE_MCOUNT_RECORD select HAVE_DYNAMIC_FTRACE + select HAVE_DYNAMIC_FTRACE_WITH_REGS if MPROFILE_KERNEL select HAVE_FUNCTION_TRACER select HAVE_FUNCTION_GRAPH_TRACER select SYSCTL_EXCEPTION_TRACE @@ -158,6 +159,7 @@ config PPC select ARCH_HAS_DEVMEM_IS_ALLOWED select HAVE_ARCH_SECCOMP_FILTER select ARCH_HAS_UBSAN_SANITIZE_ALL + select HAVE_LIVEPATCH if HAVE_DYNAMIC_FTRACE_WITH_REGS config GENERIC_CSUM def_bool CPU_LITTLE_ENDIAN @@ -373,6 +375,24 @@ config PPC_TRANSACTIONAL_MEM ---help--- Support user-mode Transactional Memory on POWERPC. +config DISABLE_MPROFILE_KERNEL + bool "Disable use of mprofile-kernel for kernel tracing" + depends on PPC64 && CPU_LITTLE_ENDIAN + default y + help + Selecting this options disables use of the mprofile-kernel ABI for + kernel tracing. That will cause options such as live patching + (CONFIG_LIVEPATCH) which depend on CONFIG_DYNAMIC_FTRACE_WITH_REGS to + be disabled also. + + If you have a toolchain which supports mprofile-kernel, then you can + enable this. Otherwise leave it disabled. If you're not sure, say + "N". + +config MPROFILE_KERNEL + depends on PPC64 && CPU_LITTLE_ENDIAN + def_bool !DISABLE_MPROFILE_KERNEL + config IOMMU_HELPER def_bool PPC64 @@ -1087,3 +1107,5 @@ config PPC_LIB_RHEAP bool source "arch/powerpc/kvm/Kconfig" + +source "kernel/livepatch/Kconfig" diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index 96efd8213c1c..f4e49a4153cb 100644 --- a/arch/powerpc/Makefile +++ b/arch/powerpc/Makefile @@ -133,6 +133,21 @@ else CFLAGS-$(CONFIG_GENERIC_CPU) += -mcpu=powerpc64 endif +ifdef CONFIG_MPROFILE_KERNEL + ifeq ($(shell $(srctree)/arch/powerpc/scripts/gcc-check-mprofile-kernel.sh $(CC) -I$(srctree)/include -D__KERNEL__),OK) + CC_FLAGS_FTRACE := -pg -mprofile-kernel + KBUILD_CPPFLAGS += -DCC_USING_MPROFILE_KERNEL + else + # If the user asked for mprofile-kernel but the toolchain doesn't + # support it, emit a warning and deliberately break the build later + # with mprofile-kernel-not-supported. We would prefer to make this an + # error right here, but then the user would never be able to run + # oldconfig to change their configuration. + $(warning Compiler does not support mprofile-kernel, set CONFIG_DISABLE_MPROFILE_KERNEL) + CC_FLAGS_FTRACE := -mprofile-kernel-not-supported + endif +endif + CFLAGS-$(CONFIG_CELL_CPU) += $(call cc-option,-mcpu=cell) CFLAGS-$(CONFIG_POWER4_CPU) += $(call cc-option,-mcpu=power4) CFLAGS-$(CONFIG_POWER5_CPU) += $(call cc-option,-mcpu=power5) diff --git a/arch/powerpc/include/asm/code-patching.h b/arch/powerpc/include/asm/code-patching.h index 840a5509b3f1..994c60a857ce 100644 --- a/arch/powerpc/include/asm/code-patching.h +++ b/arch/powerpc/include/asm/code-patching.h @@ -99,4 +99,25 @@ static inline unsigned long ppc_global_function_entry(void *func) #endif } +#ifdef CONFIG_PPC64 +/* + * Some instruction encodings commonly used in dynamic ftracing + * and function live patching. + */ + +/* This must match the definition of STK_GOT in <asm/ppc_asm.h> */ +#if defined(_CALL_ELF) && _CALL_ELF == 2 +#define R2_STACK_OFFSET 24 +#else +#define R2_STACK_OFFSET 40 +#endif + +#define PPC_INST_LD_TOC (PPC_INST_LD | ___PPC_RT(__REG_R2) | \ + ___PPC_RA(__REG_R1) | R2_STACK_OFFSET) + +/* usually preceded by a mflr r0 */ +#define PPC_INST_STD_LR (PPC_INST_STD | ___PPC_RS(__REG_R0) | \ + ___PPC_RA(__REG_R1) | PPC_LR_STKOFF) +#endif /* CONFIG_PPC64 */ + #endif /* _ASM_POWERPC_CODE_PATCHING_H */ diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/asm/ftrace.h index ef89b1465573..50ca7585abe2 100644 --- a/arch/powerpc/include/asm/ftrace.h +++ b/arch/powerpc/include/asm/ftrace.h @@ -46,6 +46,8 @@ extern void _mcount(void); #ifdef CONFIG_DYNAMIC_FTRACE +# define FTRACE_ADDR ((unsigned long)ftrace_caller) +# define FTRACE_REGS_ADDR FTRACE_ADDR static inline unsigned long ftrace_call_adjust(unsigned long addr) { /* reloction of mcount call site is the same as the address */ @@ -58,6 +60,9 @@ struct dyn_arch_ftrace { #endif /* CONFIG_DYNAMIC_FTRACE */ #endif /* __ASSEMBLY__ */ +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +#define ARCH_SUPPORTS_FTRACE_OPS 1 +#endif #endif #if defined(CONFIG_FTRACE_SYSCALLS) && defined(CONFIG_PPC64) && !defined(__ASSEMBLY__) diff --git a/arch/powerpc/include/asm/livepatch.h b/arch/powerpc/include/asm/livepatch.h new file mode 100644 index 000000000000..a402f7f94896 --- /dev/null +++ b/arch/powerpc/include/asm/livepatch.h @@ -0,0 +1,62 @@ +/* + * livepatch.h - powerpc-specific Kernel Live Patching Core + * + * Copyright (C) 2015-2016, SUSE, IBM Corp. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <http://www.gnu.org/licenses/>. + */ +#ifndef _ASM_POWERPC_LIVEPATCH_H +#define _ASM_POWERPC_LIVEPATCH_H + +#include <linux/module.h> +#include <linux/ftrace.h> + +#ifdef CONFIG_LIVEPATCH +static inline int klp_check_compiler_support(void) +{ + return 0; +} + +static inline int klp_write_module_reloc(struct module *mod, unsigned long + type, unsigned long loc, unsigned long value) +{ + /* This requires infrastructure changes; we need the loadinfos. */ + return -ENOSYS; +} + +static inline void klp_arch_set_pc(struct pt_regs *regs, unsigned long ip) +{ + regs->nip = ip; +} + +#define klp_get_ftrace_location klp_get_ftrace_location +static inline unsigned long klp_get_ftrace_location(unsigned long faddr) +{ + /* + * Live patch works only with -mprofile-kernel on PPC. In this case, + * the ftrace location is always within the first 16 bytes. + */ + return ftrace_location_range(faddr, faddr + 16); +} + +static inline void klp_init_thread_info(struct thread_info *ti) +{ + /* + 1 to account for STACK_END_MAGIC */ + ti->livepatch_sp = (unsigned long *)(ti + 1) + 1; +} +#else +static void klp_init_thread_info(struct thread_info *ti) { } +#endif /* CONFIG_LIVEPATCH */ + +#endif /* _ASM_POWERPC_LIVEPATCH_H */ diff --git a/arch/powerpc/include/asm/module.h b/arch/powerpc/include/asm/module.h index dcfcad139bcc..5b6b5a427b54 100644 --- a/arch/powerpc/include/asm/module.h +++ b/arch/powerpc/include/asm/module.h @@ -78,10 +78,18 @@ struct mod_arch_specific { # endif /* MODULE */ #endif -bool is_module_trampoline(u32 *insns); -int module_trampoline_target(struct module *mod, u32 *trampoline, +int module_trampoline_target(struct module *mod, unsigned long trampoline, unsigned long *target); +#ifdef CONFIG_DYNAMIC_FTRACE +int module_finalize_ftrace(struct module *mod, const Elf_Shdr *sechdrs); +#else +static inline int module_finalize_ftrace(struct module *mod, const Elf_Shdr *sechdrs) +{ + return 0; +} +#endif + struct exception_table_entry; void sort_ex_table(struct exception_table_entry *start, struct exception_table_entry *finish); diff --git a/arch/powerpc/include/asm/sections.h b/arch/powerpc/include/asm/sections.h index a5e930aca804..abf5866e08c6 100644 --- a/arch/powerpc/include/asm/sections.h +++ b/arch/powerpc/include/asm/sections.h @@ -22,6 +22,18 @@ static inline int in_kernel_text(unsigned long addr) return 0; } +static inline unsigned long kernel_toc_addr(void) +{ + /* Defined by the linker, see vmlinux.lds.S */ + extern unsigned long __toc_start; + + /* + * The TOC register (r2) points 32kB into the TOC, so that 64kB of + * the TOC can be addressed using a single machine instruction. + */ + return (unsigned long)(&__toc_start) + 0x8000UL; +} + static inline int overlaps_interrupt_vector_text(unsigned long start, unsigned long end) { diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h index 7efee4a3240b..8febc3f66d53 100644 --- a/arch/powerpc/include/asm/thread_info.h +++ b/arch/powerpc/include/asm/thread_info.h @@ -43,7 +43,9 @@ struct thread_info { int preempt_count; /* 0 => preemptable, <0 => BUG */ unsigned long local_flags; /* private flags for thread */ - +#ifdef CONFIG_LIVEPATCH + unsigned long *livepatch_sp; +#endif /* low level flags - has atomic operations done on it */ unsigned long flags ____cacheline_aligned_in_smp; }; diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index 794f22adf99d..2da380fcc34c 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile @@ -16,14 +16,14 @@ endif ifdef CONFIG_FUNCTION_TRACER # Do not trace early boot code -CFLAGS_REMOVE_cputable.o = -pg -mno-sched-epilog -CFLAGS_REMOVE_prom_init.o = -pg -mno-sched-epilog -CFLAGS_REMOVE_btext.o = -pg -mno-sched-epilog -CFLAGS_REMOVE_prom.o = -pg -mno-sched-epilog +CFLAGS_REMOVE_cputable.o = -mno-sched-epilog $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_prom_init.o = -mno-sched-epilog $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_btext.o = -mno-sched-epilog $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_prom.o = -mno-sched-epilog $(CC_FLAGS_FTRACE) # do not trace tracer code -CFLAGS_REMOVE_ftrace.o = -pg -mno-sched-epilog +CFLAGS_REMOVE_ftrace.o = -mno-sched-epilog $(CC_FLAGS_FTRACE) # timers used by tracing -CFLAGS_REMOVE_time.o = -pg -mno-sched-epilog +CFLAGS_REMOVE_time.o = -mno-sched-epilog $(CC_FLAGS_FTRACE) endif obj-y := cputable.o ptrace.o syscalls.o \ diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c index 07cebc3514f3..723efac2d917 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -86,6 +86,10 @@ int main(void) DEFINE(KSP_LIMIT, offsetof(struct thread_struct, ksp_limit)); #endif /* CONFIG_PPC64 */ +#ifdef CONFIG_LIVEPATCH + DEFINE(TI_livepatch_sp, offsetof(struct thread_info, livepatch_sp)); +#endif + DEFINE(KSP, offsetof(struct thread_struct, ksp)); DEFINE(PT_REGS, offsetof(struct thread_struct, regs)); #ifdef CONFIG_BOOKE diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index 0d525ce3717f..47dbede3bddd 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -20,6 +20,7 @@ #include <linux/errno.h> #include <linux/err.h> +#include <linux/magic.h> #include <asm/unistd.h> #include <asm/processor.h> #include <asm/page.h> @@ -1143,8 +1144,12 @@ _GLOBAL(enter_prom) #ifdef CONFIG_DYNAMIC_FTRACE _GLOBAL(mcount) _GLOBAL(_mcount) - blr + mflr r12 + mtctr r12 + mtlr r0 + bctr +#ifndef CC_USING_MPROFILE_KERNEL _GLOBAL_TOC(ftrace_caller) /* Taken from output of objdump from lib64/glibc */ mflr r3 @@ -1166,8 +1171,213 @@ _GLOBAL(ftrace_graph_stub) ld r0, 128(r1) mtlr r0 addi r1, r1, 112 + +#else /* CC_USING_MPROFILE_KERNEL */ +/* + * + * ftrace_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_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(0,r1) + SAVE_8GPRS(8,r1) + SAVE_8GPRS(16,r1) + SAVE_8GPRS(24,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 & pt_regs->link */ + std r7, _NIP(r1) + std r7, _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_call +ftrace_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_8GPRS(0,r1) + REST_8GPRS(8,r1) + REST_8GPRS(16,r1) + REST_8GPRS(24,r1) + + /* Restore callee's TOC */ + ld r2, 24(r1) + + /* Pop our stack frame */ + addi r1, r1, SWITCH_FRAME_SIZE + + /* Restore original LR for return to B */ + ld r0, LRSAVE(r1) + mtlr r0 + +#ifdef CONFIG_LIVEPATCH + /* Based on the cmpd above, if the NIP was altered handle livepatch */ + bne- livepatch_handler +#endif + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + stdu r1, -112(r1) +.globl ftrace_graph_call +ftrace_graph_call: + b ftrace_graph_stub +_GLOBAL(ftrace_graph_stub) + addi r1, r1, 112 +#endif + + ld r0,LRSAVE(r1) /* restore callee's lr at _mcount site */ + mtlr r0 + bctr /* jump after _mcount site */ +#endif /* CC_USING_MPROFILE_KERNEL */ + _GLOBAL(ftrace_stub) blr + +#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 & r12 are free + * + * r0 can't be used as the base register for a DS-form load or store, so + * we temporarily shuffle r1 (stack pointer) into r0 and then put it back. + */ +livepatch_handler: + CURRENT_THREAD_INFO(r12, r1) + + /* Save stack pointer into r0 */ + mr r0, r1 + + /* Allocate 3 x 8 bytes */ + ld r1, TI_livepatch_sp(r12) + addi r1, r1, 24 + std r1, TI_livepatch_sp(r12) + + /* Save toc & real LR on livepatch stack */ + std r2, -24(r1) + mflr r12 + std r12, -16(r1) + + /* Store stack end marker */ + lis r12, STACK_END_MAGIC@h + ori r12, r12, STACK_END_MAGIC@l + std r12, -8(r1) + + /* Restore real stack pointer */ + mr r1, r0 + + /* 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 r0 and r12, and we can use r2 until we + * restore it. + */ + + CURRENT_THREAD_INFO(r12, r1) + + /* Save stack pointer into r0 */ + mr r0, r1 + + ld r1, 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(r1) +1: tdne r12, r2 + EMIT_BUG_ENTRY 1b, __FILE__, __LINE__ - 1, 0 + + /* Restore LR & toc from livepatch stack */ + ld r12, -16(r1) + mtlr r12 + ld r2, -24(r1) + + /* Pop livepatch stack frame */ + CURRENT_THREAD_INFO(r12, r0) + subi r1, r1, 24 + std r1, TI_livepatch_sp(r12) + + /* Restore real stack pointer */ + mr r1, r0 + + /* Return to original caller of live patched function */ + blr +#endif + + #else _GLOBAL_TOC(_mcount) /* Taken from output of objdump from lib64/glibc */ @@ -1198,6 +1408,7 @@ _GLOBAL(ftrace_stub) #endif /* CONFIG_DYNAMIC_FTRACE */ #ifdef CONFIG_FUNCTION_GRAPH_TRACER +#ifndef CC_USING_MPROFILE_KERNEL _GLOBAL(ftrace_graph_caller) /* load r4 with local address */ ld r4, 128(r1) @@ -1222,6 +1433,56 @@ _GLOBAL(ftrace_graph_caller) addi r1, r1, 112 blr +#else /* CC_USING_MPROFILE_KERNEL */ +_GLOBAL(ftrace_graph_caller) + /* 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 */ + + 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 /* CC_USING_MPROFILE_KERNEL */ + _GLOBAL(return_to_handler) /* need to save return values */ std r4, -32(r1) diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c index 44d4d8eb3c85..9dac18dabd03 100644 --- a/arch/powerpc/kernel/ftrace.c +++ b/arch/powerpc/kernel/ftrace.c @@ -61,8 +61,11 @@ ftrace_modify_code(unsigned long ip, unsigned int old, unsigned int new) return -EFAULT; /* Make sure it is what we expect it to be */ - if (replaced != old) + if (replaced != old) { + pr_err("%p: replaced (%#x) != old (%#x)", + (void *)ip, replaced, old); return -EINVAL; + } /* replace the text with the new text */ if (patch_instruction((unsigned int *)ip, new)) @@ -106,14 +109,15 @@ static int __ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr) { - unsigned int op; - unsigned long entry, ptr; + unsigned long entry, ptr, tramp; unsigned long ip = rec->ip; - void *tramp; + unsigned int op, pop; /* read where this goes */ - if (probe_kernel_read(&op, (void *)ip, sizeof(int))) + 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)) { @@ -122,14 +126,9 @@ __ftrace_make_nop(struct module *mod, } /* lets find where the pointer goes */ - tramp = (void *)find_bl_target(ip, op); - - pr_devel("ip:%lx jumps to %p", ip, tramp); + tramp = find_bl_target(ip, op); - if (!is_module_trampoline(tramp)) { - pr_err("Not a trampoline\n"); - return -EINVAL; - } + pr_devel("ip:%lx jumps to %lx", ip, tramp); if (module_trampoline_target(mod, tramp, &ptr)) { pr_err("Failed to get trampoline target\n"); @@ -158,10 +157,42 @@ __ftrace_make_nop(struct module *mod, * * Use a b +8 to jump over the load. */ - op = 0x48000008; /* b +8 */ - if (patch_instruction((unsigned int *)ip, op)) + 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) { + unsigned int inst; + + if (probe_kernel_read(&inst, (void *)(ip - 4), 4)) { + pr_err("Fetching instruction at %lx failed.\n", ip - 4); + return -EFAULT; + } + + /* We expect either a mlfr r0, or a std r0, LRSAVE(r1) */ + if (inst != PPC_INST_MFLR && inst != PPC_INST_STD_LR) { + pr_err("Unexpected instructions around bl _mcount\n" + "when enabling dynamic ftrace!\t" + "(%08x,bl,%08x)\n", inst, op); + return -EINVAL; + } + + /* When using -mkernel_profile there is no load to jump over */ + pop = PPC_INST_NOP; + } + + if (patch_instruction((unsigned int *)ip, pop)) { + pr_err("Patching NOP failed.\n"); return -EPERM; + } return 0; } @@ -287,16 +318,15 @@ int ftrace_make_nop(struct module *mod, #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 CC_USING_MPROFILE_KERNEL static int -__ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) +expected_nop_sequence(void *ip, unsigned int op0, unsigned int op1) { - unsigned int op[2]; - void *ip = (void *)rec->ip; - - /* read where this goes */ - if (probe_kernel_read(op, ip, sizeof(op))) - return -EFAULT; - /* * We expect to see: * @@ -306,8 +336,34 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) * The load offset is different depending on the ABI. For simplicity * just mask it out when doing the compare. */ - if ((op[0] != 0x48000008) || ((op[1] & 0xffff0000) != 0xe8410000)) { - pr_err("Unexpected call sequence: %x %x\n", op[0], op[1]); + 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; +} +#endif + +static int +__ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) +{ + unsigned int op[2]; + void *ip = (void *)rec->ip; + + /* read where this goes */ + if (probe_kernel_read(op, ip, sizeof(op))) + return -EFAULT; + + if (!expected_nop_sequence(ip, op[0], op[1])) { + pr_err("Unexpected call sequence at %p: %x %x\n", + ip, op[0], op[1]); return -EINVAL; } @@ -330,7 +386,16 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) return 0; } -#else + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, + unsigned long addr) +{ + return ftrace_make_call(rec, addr); +} +#endif + +#else /* !CONFIG_PPC64: */ static int __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) { @@ -455,20 +520,13 @@ void ftrace_replace_code(int enable) } } +/* + * Use the default ftrace_modify_all_code, but without + * stop_machine(). + */ void arch_ftrace_update_code(int command) { - if (command & FTRACE_UPDATE_CALLS) - ftrace_replace_code(1); - else if (command & FTRACE_DISABLE_CALLS) - ftrace_replace_code(0); - - if (command & FTRACE_UPDATE_TRACE_FUNC) - ftrace_update_ftrace_func(ftrace_trace_function); - - if (command & FTRACE_START_FUNC_RET) - ftrace_enable_ftrace_graph_caller(); - else if (command & FTRACE_STOP_FUNC_RET) - ftrace_disable_ftrace_graph_caller(); + ftrace_modify_all_code(command); } int __init ftrace_dyn_arch_init(void) diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c index 290559df1e8b..3cb46a3b1de7 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -66,6 +66,7 @@ #include <asm/udbg.h> #include <asm/smp.h> #include <asm/debug.h> +#include <asm/livepatch.h> #ifdef CONFIG_PPC64 #include <asm/paca.h> @@ -607,10 +608,12 @@ void irq_ctx_init(void) memset((void *)softirq_ctx[i], 0, THREAD_SIZE); tp = softirq_ctx[i]; tp->cpu = i; + klp_init_thread_info(tp); memset((void *)hardirq_ctx[i], 0, THREAD_SIZE); tp = hardirq_ctx[i]; tp->cpu = i; + klp_init_thread_info(tp); } } diff --git a/arch/powerpc/kernel/module.c b/arch/powerpc/kernel/module.c index 9547381b631a..d1f1b35bf0c7 100644 --- a/arch/powerpc/kernel/module.c +++ b/arch/powerpc/kernel/module.c @@ -47,6 +47,11 @@ int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, struct module *me) { const Elf_Shdr *sect; + int rc; + + rc = module_finalize_ftrace(me, sechdrs); + if (rc) + return rc; /* Apply feature fixups */ sect = find_section(hdr, sechdrs, "__ftr_fixup"); diff --git a/arch/powerpc/kernel/module_32.c b/arch/powerpc/kernel/module_32.c index 2c01665eb410..5a7a78f12562 100644 --- a/arch/powerpc/kernel/module_32.c +++ b/arch/powerpc/kernel/module_32.c @@ -181,7 +181,7 @@ static inline int entry_matches(struct ppc_plt_entry *entry, Elf32_Addr val) /* Set up a trampoline in the PLT to bounce us to the distant function */ static uint32_t do_plt_call(void *location, Elf32_Addr val, - Elf32_Shdr *sechdrs, + const Elf32_Shdr *sechdrs, struct module *mod) { struct ppc_plt_entry *entry; @@ -294,11 +294,19 @@ int apply_relocate_add(Elf32_Shdr *sechdrs, return -ENOEXEC; } } + + return 0; +} + #ifdef CONFIG_DYNAMIC_FTRACE - module->arch.tramp = - do_plt_call(module->core_layout.base, - (unsigned long)ftrace_caller, - sechdrs, module); -#endif +int module_finalize_ftrace(struct module *module, const Elf_Shdr *sechdrs) +{ + module->arch.tramp = do_plt_call(module->core_layout.base, + (unsigned long)ftrace_caller, + sechdrs, module); + if (!module->arch.tramp) + return -ENOENT; + return 0; } +#endif diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c index 08b7a40de5f8..9ce9a25f58b5 100644 --- a/arch/powerpc/kernel/module_64.c +++ b/arch/powerpc/kernel/module_64.c @@ -31,6 +31,7 @@ #include <asm/code-patching.h> #include <linux/sort.h> #include <asm/setup.h> +#include <asm/sections.h> /* FIXME: We don't do .init separately. To do this, we'd need to have a separate r2 value in the init and core section, and stub between @@ -41,7 +42,6 @@ --RR. */ #if defined(_CALL_ELF) && _CALL_ELF == 2 -#define R2_STACK_OFFSET 24 /* An address is simply the address of the function. */ typedef unsigned long func_desc_t; @@ -73,7 +73,6 @@ static unsigned int local_entry_offset(const Elf64_Sym *sym) return PPC64_LOCAL_ENTRY_OFFSET(sym->st_other); } #else -#define R2_STACK_OFFSET 40 /* An address is address of the OPD entry, which contains address of fn. |