diff options
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/Kconfig | 18 | ||||
| -rw-r--r-- | arch/arm64/Makefile | 2 | ||||
| -rw-r--r-- | arch/arm64/include/asm/ftrace.h | 72 | ||||
| -rw-r--r-- | arch/arm64/kernel/asm-offsets.c | 13 | ||||
| -rw-r--r-- | arch/arm64/kernel/entry-ftrace.S | 117 | ||||
| -rw-r--r-- | arch/arm64/kernel/ftrace.c | 82 | ||||
| -rw-r--r-- | arch/arm64/kernel/module.c | 3 |
7 files changed, 184 insertions, 123 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 505c8a1ccbe0..b6b3305ba701 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -181,8 +181,10 @@ config ARM64 select HAVE_DEBUG_KMEMLEAK select HAVE_DMA_CONTIGUOUS select HAVE_DYNAMIC_FTRACE + select HAVE_DYNAMIC_FTRACE_WITH_ARGS \ + if $(cc-option,-fpatchable-function-entry=2) select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \ - if DYNAMIC_FTRACE_WITH_REGS + if DYNAMIC_FTRACE_WITH_ARGS select HAVE_EFFICIENT_UNALIGNED_ACCESS select HAVE_FAST_GUP select HAVE_FTRACE_MCOUNT_RECORD @@ -233,16 +235,16 @@ config ARM64 help ARM 64-bit (AArch64) Linux support. -config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_REGS +config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS def_bool CC_IS_CLANG # https://github.com/ClangBuiltLinux/linux/issues/1507 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) - select HAVE_DYNAMIC_FTRACE_WITH_REGS + select HAVE_DYNAMIC_FTRACE_WITH_ARGS -config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_REGS +config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS def_bool CC_IS_GCC depends on $(cc-option,-fpatchable-function-entry=2) - select HAVE_DYNAMIC_FTRACE_WITH_REGS + select HAVE_DYNAMIC_FTRACE_WITH_ARGS config 64BIT def_bool y @@ -1816,7 +1818,7 @@ config ARM64_PTR_AUTH_KERNEL # which is only understood by binutils starting with version 2.33.1. depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100) depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE - depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_REGS) + depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) help If the compiler supports the -mbranch-protection or -msign-return-address flag (e.g. GCC 7 or later), then this option @@ -1826,7 +1828,7 @@ config ARM64_PTR_AUTH_KERNEL disabled with minimal loss of protection. This feature works with FUNCTION_GRAPH_TRACER option only if - DYNAMIC_FTRACE_WITH_REGS is enabled. + DYNAMIC_FTRACE_WITH_ARGS is enabled. config CC_HAS_BRANCH_PROT_PAC_RET # GCC 9 or later, clang 8 or later @@ -1924,7 +1926,7 @@ config ARM64_BTI_KERNEL depends on !CC_IS_GCC # https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9 depends on !CC_IS_CLANG || CLANG_VERSION >= 120000 - depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_REGS) + depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) help Build the kernel with Branch Target Identification annotations and enable enforcement of this for kernel code. When this option diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile index 5e56d26a2239..b1202fa84bab 100644 --- a/arch/arm64/Makefile +++ b/arch/arm64/Makefile @@ -128,7 +128,7 @@ endif CHECKFLAGS += -D__aarch64__ -ifeq ($(CONFIG_DYNAMIC_FTRACE_WITH_REGS),y) +ifeq ($(CONFIG_DYNAMIC_FTRACE_WITH_ARGS),y) KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY CC_FLAGS_FTRACE := -fpatchable-function-entry=2 endif diff --git a/arch/arm64/include/asm/ftrace.h b/arch/arm64/include/asm/ftrace.h index 329dbbd4d50b..5664729800ae 100644 --- a/arch/arm64/include/asm/ftrace.h +++ b/arch/arm64/include/asm/ftrace.h @@ -23,7 +23,7 @@ */ #define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR -#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS #define ARCH_SUPPORTS_FTRACE_OPS 1 #else #define MCOUNT_ADDR ((unsigned long)_mcount) @@ -33,8 +33,7 @@ #define MCOUNT_INSN_SIZE AARCH64_INSN_SIZE #define FTRACE_PLT_IDX 0 -#define FTRACE_REGS_PLT_IDX 1 -#define NR_FTRACE_PLTS 2 +#define NR_FTRACE_PLTS 1 /* * Currently, gcc tends to save the link register after the local variables @@ -69,7 +68,7 @@ static inline unsigned long ftrace_call_adjust(unsigned long addr) * Adjust addr to point at the BL in the callsite. * See ftrace_init_nop() for the callsite sequence. */ - if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS)) + if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_ARGS)) return addr + AARCH64_INSN_SIZE; /* * addr is the address of the mcount call instruction. @@ -78,10 +77,71 @@ static inline unsigned long ftrace_call_adjust(unsigned long addr) return addr; } -#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS struct dyn_ftrace; struct ftrace_ops; -struct ftrace_regs; + +#define arch_ftrace_get_regs(regs) NULL + +struct ftrace_regs { + /* x0 - x8 */ + unsigned long regs[9]; + unsigned long __unused; + + unsigned long fp; + unsigned long lr; + + unsigned long sp; + unsigned long pc; +}; + +static __always_inline unsigned long +ftrace_regs_get_instruction_pointer(const struct ftrace_regs *fregs) +{ + return fregs->pc; +} + +static __always_inline void +ftrace_regs_set_instruction_pointer(struct ftrace_regs *fregs, + unsigned long pc) +{ + fregs->pc = pc; +} + +static __always_inline unsigned long +ftrace_regs_get_stack_pointer(const struct ftrace_regs *fregs) +{ + return fregs->sp; +} + +static __always_inline unsigned long +ftrace_regs_get_argument(struct ftrace_regs *fregs, unsigned int n) +{ + if (n < 8) + return fregs->regs[n]; + return 0; +} + +static __always_inline unsigned long +ftrace_regs_get_return_value(const struct ftrace_regs *fregs) +{ + return fregs->regs[0]; +} + +static __always_inline void +ftrace_regs_set_return_value(struct ftrace_regs *fregs, + unsigned long ret) +{ + fregs->regs[0] = ret; +} + +static __always_inline void +ftrace_override_function_with_return(struct ftrace_regs *fregs) +{ + fregs->pc = fregs->lr; +} + +int ftrace_regs_query_register_offset(const char *name); int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec); #define ftrace_init_nop ftrace_init_nop diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index 1197e7679882..2234624536d9 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -82,6 +82,19 @@ int main(void) DEFINE(S_STACKFRAME, offsetof(struct pt_regs, stackframe)); DEFINE(PT_REGS_SIZE, sizeof(struct pt_regs)); BLANK(); +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS + DEFINE(FREGS_X0, offsetof(struct ftrace_regs, regs[0])); + DEFINE(FREGS_X2, offsetof(struct ftrace_regs, regs[2])); + DEFINE(FREGS_X4, offsetof(struct ftrace_regs, regs[4])); + DEFINE(FREGS_X6, offsetof(struct ftrace_regs, regs[6])); + DEFINE(FREGS_X8, offsetof(struct ftrace_regs, regs[8])); + DEFINE(FREGS_FP, offsetof(struct ftrace_regs, fp)); + DEFINE(FREGS_LR, offsetof(struct ftrace_regs, lr)); + DEFINE(FREGS_SP, offsetof(struct ftrace_regs, sp)); + DEFINE(FREGS_PC, offsetof(struct ftrace_regs, pc)); + DEFINE(FREGS_SIZE, sizeof(struct ftrace_regs)); + BLANK(); +#endif #ifdef CONFIG_COMPAT DEFINE(COMPAT_SIGFRAME_REGS_OFFSET, offsetof(struct compat_sigframe, uc.uc_mcontext.arm_r0)); DEFINE(COMPAT_RT_SIGFRAME_REGS_OFFSET, offsetof(struct compat_rt_sigframe, sig.uc.uc_mcontext.arm_r0)); diff --git a/arch/arm64/kernel/entry-ftrace.S b/arch/arm64/kernel/entry-ftrace.S index 795344ab4ec4..4d3050549aa6 100644 --- a/arch/arm64/kernel/entry-ftrace.S +++ b/arch/arm64/kernel/entry-ftrace.S @@ -13,83 +13,58 @@ #include <asm/ftrace.h> #include <asm/insn.h> -#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS /* * Due to -fpatchable-function-entry=2, the compiler has placed two NOPs before * the regular function prologue. For an enabled callsite, ftrace_init_nop() and * ftrace_make_call() have patched those NOPs to: * * MOV X9, LR - * BL <entry> - * - * ... where <entry> is either ftrace_caller or ftrace_regs_caller. + * BL ftrace_caller * * Each instrumented function follows the AAPCS, so here x0-x8 and x18-x30 are * live (x18 holds the Shadow Call Stack pointer), and x9-x17 are safe to * clobber. * - * We save the callsite's context into a pt_regs before invoking any ftrace - * callbacks. So that we can get a sensible backtrace, we create a stack record - * for the callsite and the ftrace entry assembly. This is not sufficient for - * reliable stacktrace: until we create the callsite stack record, its caller - * is missing from the LR and existing chain of frame records. + * We save the callsite's context into a struct ftrace_regs before invoking any + * ftrace callbacks. So that we can get a sensible backtrace, we create frame + * records for the callsite and the ftrace entry assembly. This is not + * sufficient for reliable stacktrace: until we create the callsite stack + * record, its caller is missing from the LR and existing chain of frame + * records. */ - .macro ftrace_regs_entry, allregs=0 - /* Make room for pt_regs, plus a callee frame */ - sub sp, sp, #(PT_REGS_SIZE + 16) - - /* Save function arguments (and x9 for simplicity) */ - stp x0, x1, [sp, #S_X0] - stp x2, x3, [sp, #S_X2] - stp x4, x5, [sp, #S_X4] - stp x6, x7, [sp, #S_X6] - stp x8, x9, [sp, #S_X8] - - /* Optionally save the callee-saved registers, always save the FP */ - .if \allregs == 1 - stp x10, x11, [sp, #S_X10] - stp x12, x13, [sp, #S_X12] - stp x14, x15, [sp, #S_X14] - stp x16, x17, [sp, #S_X16] - stp x18, x19, [sp, #S_X18] - stp x20, x21, [sp, #S_X20] - stp x22, x23, [sp, #S_X22] - stp x24, x25, [sp, #S_X24] - stp x26, x27, [sp, #S_X26] - stp x28, x29, [sp, #S_X28] - .else - str x29, [sp, #S_FP] - .endif - - /* Save the callsite's SP and LR */ - add x10, sp, #(PT_REGS_SIZE + 16) - stp x9, x10, [sp, #S_LR] +SYM_CODE_START(ftrace_caller) + bti c - /* Save the PC after the ftrace callsite */ - str x30, [sp, #S_PC] + /* Save original SP */ + mov x10, sp - /* Create a frame record for the callsite above pt_regs */ - stp x29, x9, [sp, #PT_REGS_SIZE] - add x29, sp, #PT_REGS_SIZE + /* Make room for ftrace regs, plus two frame records */ + sub sp, sp, #(FREGS_SIZE + 32) - /* Create our frame record within pt_regs. */ - stp x29, x30, [sp, #S_STACKFRAME] - add x29, sp, #S_STACKFRAME - .endm + /* Save function arguments */ + stp x0, x1, [sp, #FREGS_X0] + stp x2, x3, [sp, #FREGS_X2] + stp x4, x5, [sp, #FREGS_X4] + stp x6, x7, [sp, #FREGS_X6] + str x8, [sp, #FREGS_X8] -SYM_CODE_START(ftrace_regs_caller) - bti c - ftrace_regs_entry 1 - b ftrace_common -SYM_CODE_END(ftrace_regs_caller) + /* Save the callsite's FP, LR, SP */ + str x29, [sp, #FREGS_FP] + str x9, [sp, #FREGS_LR] + str x10, [sp, #FREGS_SP] -SYM_CODE_START(ftrace_caller) - bti c - ftrace_regs_entry 0 - b ftrace_common -SYM_CODE_END(ftrace_caller) + /* Save the PC after the ftrace callsite */ + str x30, [sp, #FREGS_PC] + + /* Create a frame record for the callsite above the ftrace regs */ + stp x29, x9, [sp, #FREGS_SIZE + 16] + add x29, sp, #FREGS_SIZE + 16 + + /* Create our frame record above the ftrace regs */ + stp x29, x30, [sp, #FREGS_SIZE] + add x29, sp, #FREGS_SIZE -SYM_CODE_START(ftrace_common) sub x0, x30, #AARCH64_INSN_SIZE // ip (callsite's BL insn) mov x1, x9 // parent_ip (callsite's LR) ldr_l x2, function_trace_op // op @@ -104,24 +79,24 @@ SYM_INNER_LABEL(ftrace_call, SYM_L_GLOBAL) * to restore x0-x8, x29, and x30. */ /* Restore function arguments */ - ldp x0, x1, [sp] - ldp x2, x3, [sp, #S_X2] - ldp x4, x5, [sp, #S_X4] - ldp x6, x7, [sp, #S_X6] - ldr x8, [sp, #S_X8] + ldp x0, x1, [sp, #FREGS_X0] + ldp x2, x3, [sp, #FREGS_X2] + ldp x4, x5, [sp, #FREGS_X4] + ldp x6, x7, [sp, #FREGS_X6] + ldr x8, [sp, #FREGS_X8] /* Restore the callsite's FP, LR, PC */ - ldr x29, [sp, #S_FP] - ldr x30, [sp, #S_LR] - ldr x9, [sp, #S_PC] + ldr x29, [sp, #FREGS_FP] + ldr x30, [sp, #FREGS_LR] + ldr x9, [sp, #FREGS_PC] /* Restore the callsite's SP */ - add sp, sp, #PT_REGS_SIZE + 16 + add sp, sp, #FREGS_SIZE + 32 ret x9 -SYM_CODE_END(ftrace_common) +SYM_CODE_END(ftrace_caller) -#else /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ +#else /* CONFIG_DYNAMIC_FTRACE_WITH_ARGS */ /* * Gcc with -pg will put the following code in the beginning of each function: @@ -293,7 +268,7 @@ SYM_FUNC_START(ftrace_graph_caller) mcount_exit SYM_FUNC_END(ftrace_graph_caller) #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ -#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_ARGS */ SYM_TYPED_FUNC_START(ftrace_stub) ret diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c index 8745175f4a75..5cf990d052ba 100644 --- a/arch/arm64/kernel/ftrace.c +++ b/arch/arm64/kernel/ftrace.c @@ -17,6 +17,49 @@ #include <asm/insn.h> #include <asm/patching.h> +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS +struct fregs_offset { + const char *name; + int offset; +}; + +#define FREGS_OFFSET(n, field) \ +{ \ + .name = n, \ + .offset = offsetof(struct ftrace_regs, field), \ +} + +static const struct fregs_offset fregs_offsets[] = { + FREGS_OFFSET("x0", regs[0]), + FREGS_OFFSET("x1", regs[1]), + FREGS_OFFSET("x2", regs[2]), + FREGS_OFFSET("x3", regs[3]), + FREGS_OFFSET("x4", regs[4]), + FREGS_OFFSET("x5", regs[5]), + FREGS_OFFSET("x6", regs[6]), + FREGS_OFFSET("x7", regs[7]), + FREGS_OFFSET("x8", regs[8]), + + FREGS_OFFSET("x29", fp), + FREGS_OFFSET("x30", lr), + FREGS_OFFSET("lr", lr), + + FREGS_OFFSET("sp", sp), + FREGS_OFFSET("pc", pc), +}; + +int ftrace_regs_query_register_offset(const char *name) +{ + for (int i = 0; i < ARRAY_SIZE(fregs_offsets); i++) { + const struct fregs_offset *roff = &fregs_offsets[i]; + if (!strcmp(roff->name, name)) + return roff->offset; + } + + return -EINVAL; +} +#endif + #ifdef CONFIG_DYNAMIC_FTRACE /* * Replace a single instruction, which may be a branch or NOP. @@ -70,9 +113,6 @@ static struct plt_entry *get_ftrace_plt(struct module *mod, unsigned long addr) if (addr == FTRACE_ADDR) return &plt[FTRACE_PLT_IDX]; - if (addr == FTRACE_REGS_ADDR && - IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS)) - return &plt[FTRACE_REGS_PLT_IDX]; #endif return NULL; } @@ -154,25 +194,7 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) return ftrace_modify_code(pc, old, new, true); } -#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS -int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, - unsigned long addr) -{ - unsigned long pc = rec->ip; - u32 old, new; - - if (!ftrace_find_callable_addr(rec, NULL, &old_addr)) - return -EINVAL; - if (!ftrace_find_callable_addr(rec, NULL, &addr)) - return -EINVAL; - - old = aarch64_insn_gen_branch_imm(pc, old_addr, - AARCH64_INSN_BRANCH_LINK); - new = aarch64_insn_gen_branch_imm(pc, addr, AARCH64_INSN_BRANCH_LINK); - - return ftrace_modify_code(pc, old, new, true); -} - +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS /* * The compiler has inserted two NOPs before the regular function prologue. * All instrumented functions follow the AAPCS, so x0-x8 and x19-x30 are live, @@ -228,7 +250,7 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, * * Note: 'mod' is only set at module load time. */ - if (!IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) && + if (!IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_ARGS) && IS_ENABLED(CONFIG_ARM64_MODULE_PLTS) && mod) { return aarch64_insn_patch_text_nosync((void *)pc, new); } @@ -279,19 +301,11 @@ void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent, #ifdef CONFIG_DYNAMIC_FTRACE -#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +#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) { - /* - * When DYNAMIC_FTRACE_WITH_REGS is selected, `fregs` can never be NULL - * and arch_ftrace_get_regs(fregs) will always give a non-NULL pt_regs - * in which we can safely modify the LR. - */ - struct pt_regs *regs = arch_ftrace_get_regs(fregs); - unsigned long *parent = (unsigned long *)&procedure_link_pointer(regs); - - prepare_ftrace_return(ip, parent, frame_pointer(regs)); + prepare_ftrace_return(ip, &fregs->lr, fregs->fp); } #else /* @@ -323,6 +337,6 @@ int ftrace_disable_ftrace_graph_caller(void) { return ftrace_modify_graph_caller(false); } -#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_ARGS */ #endif /* CONFIG_DYNAMIC_FTRACE */ #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c index 76b41e4ca9fa..acd0d883e9ca 100644 --- a/arch/arm64/kernel/module.c +++ b/arch/arm64/kernel/module.c @@ -497,9 +497,6 @@ static int module_init_ftrace_plt(const Elf_Ehdr *hdr, __init_plt(&plts[FTRACE_PLT_IDX], FTRACE_ADDR); - if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS)) - __init_plt(&plts[FTRACE_REGS_PLT_IDX], FTRACE_REGS_ADDR); - mod->arch.ftrace_trampolines = plts; #endif return 0; |