diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/Kconfig | 3 | ||||
| -rw-r--r-- | arch/arm64/include/asm/cacheflush.h | 1 | ||||
| -rw-r--r-- | arch/arm64/include/asm/debug-monitors.h | 3 | ||||
| -rw-r--r-- | arch/arm64/include/asm/ptrace.h | 8 | ||||
| -rw-r--r-- | arch/arm64/include/asm/thread_info.h | 5 | ||||
| -rw-r--r-- | arch/arm64/include/asm/uprobes.h | 36 | ||||
| -rw-r--r-- | arch/arm64/kernel/probes/Makefile | 2 | ||||
| -rw-r--r-- | arch/arm64/kernel/probes/uprobes.c | 216 | ||||
| -rw-r--r-- | arch/arm64/kernel/signal.c | 3 | ||||
| -rw-r--r-- | arch/arm64/mm/flush.c | 2 |
10 files changed, 277 insertions, 2 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 969ef880d234..77a807a844ac 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -238,6 +238,9 @@ config PGTABLE_LEVELS default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 +config ARCH_SUPPORTS_UPROBES + def_bool y + source "init/Kconfig" source "kernel/Kconfig.freezer" diff --git a/arch/arm64/include/asm/cacheflush.h b/arch/arm64/include/asm/cacheflush.h index 2e5fb976a572..e9f64ecb75ce 100644 --- a/arch/arm64/include/asm/cacheflush.h +++ b/arch/arm64/include/asm/cacheflush.h @@ -71,6 +71,7 @@ extern void __flush_dcache_area(void *addr, size_t len); extern void __clean_dcache_area_poc(void *addr, size_t len); extern void __clean_dcache_area_pou(void *addr, size_t len); extern long __flush_cache_user_range(unsigned long start, unsigned long end); +extern void sync_icache_aliases(void *kaddr, unsigned long len); static inline void flush_cache_mm(struct mm_struct *mm) { diff --git a/arch/arm64/include/asm/debug-monitors.h b/arch/arm64/include/asm/debug-monitors.h index b71420a12f26..a44cf5225429 100644 --- a/arch/arm64/include/asm/debug-monitors.h +++ b/arch/arm64/include/asm/debug-monitors.h @@ -68,6 +68,9 @@ #define BRK64_ESR_MASK 0xFFFF #define BRK64_ESR_KPROBES 0x0004 #define BRK64_OPCODE_KPROBES (AARCH64_BREAK_MON | (BRK64_ESR_KPROBES << 5)) +/* uprobes BRK opcodes with ESR encoding */ +#define BRK64_ESR_UPROBES 0x0005 +#define BRK64_OPCODE_UPROBES (AARCH64_BREAK_MON | (BRK64_ESR_UPROBES << 5)) /* AArch32 */ #define DBG_ESR_EVT_BKPT 0x4 diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h index ada08b5b036d..513daf050e84 100644 --- a/arch/arm64/include/asm/ptrace.h +++ b/arch/arm64/include/asm/ptrace.h @@ -217,6 +217,14 @@ int valid_user_regs(struct user_pt_regs *regs, struct task_struct *task); #include <asm-generic/ptrace.h> +#define procedure_link_pointer(regs) ((regs)->regs[30]) + +static inline void procedure_link_pointer_set(struct pt_regs *regs, + unsigned long val) +{ + procedure_link_pointer(regs) = val; +} + #undef profile_pc extern unsigned long profile_pc(struct pt_regs *regs); diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h index e9ea5a6bd449..f6859831462e 100644 --- a/arch/arm64/include/asm/thread_info.h +++ b/arch/arm64/include/asm/thread_info.h @@ -112,6 +112,7 @@ static inline struct thread_info *current_thread_info(void) #define TIF_NEED_RESCHED 1 #define TIF_NOTIFY_RESUME 2 /* callback before returning to user */ #define TIF_FOREIGN_FPSTATE 3 /* CPU's FP state is not current's */ +#define TIF_UPROBE 4 /* uprobe breakpoint or singlestep */ #define TIF_NOHZ 7 #define TIF_SYSCALL_TRACE 8 #define TIF_SYSCALL_AUDIT 9 @@ -132,10 +133,12 @@ static inline struct thread_info *current_thread_info(void) #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT) #define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT) #define _TIF_SECCOMP (1 << TIF_SECCOMP) +#define _TIF_UPROBE (1 << TIF_UPROBE) #define _TIF_32BIT (1 << TIF_32BIT) #define _TIF_WORK_MASK (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \ - _TIF_NOTIFY_RESUME | _TIF_FOREIGN_FPSTATE) + _TIF_NOTIFY_RESUME | _TIF_FOREIGN_FPSTATE | \ + _TIF_UPROBE) #define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \ _TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP | \ diff --git a/arch/arm64/include/asm/uprobes.h b/arch/arm64/include/asm/uprobes.h new file mode 100644 index 000000000000..8d004073d0e8 --- /dev/null +++ b/arch/arm64/include/asm/uprobes.h @@ -0,0 +1,36 @@ +/* + * Copyright (C) 2014-2016 Pratyush Anand <panand@redhat.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifndef _ASM_UPROBES_H +#define _ASM_UPROBES_H + +#include <asm/debug-monitors.h> +#include <asm/insn.h> +#include <asm/probes.h> + +#define MAX_UINSN_BYTES AARCH64_INSN_SIZE + +#define UPROBE_SWBP_INSN BRK64_OPCODE_UPROBES +#define UPROBE_SWBP_INSN_SIZE AARCH64_INSN_SIZE +#define UPROBE_XOL_SLOT_BYTES MAX_UINSN_BYTES + +typedef u32 uprobe_opcode_t; + +struct arch_uprobe_task { +}; + +struct arch_uprobe { + union { + u8 insn[MAX_UINSN_BYTES]; + u8 ixol[MAX_UINSN_BYTES]; + }; + struct arch_probe_insn api; + bool simulate; +}; + +#endif diff --git a/arch/arm64/kernel/probes/Makefile b/arch/arm64/kernel/probes/Makefile index ce06312e3d34..89b6df613dde 100644 --- a/arch/arm64/kernel/probes/Makefile +++ b/arch/arm64/kernel/probes/Makefile @@ -1,3 +1,5 @@ obj-$(CONFIG_KPROBES) += kprobes.o decode-insn.o \ kprobes_trampoline.o \ simulate-insn.o +obj-$(CONFIG_UPROBES) += uprobes.o decode-insn.o \ + simulate-insn.o diff --git a/arch/arm64/kernel/probes/uprobes.c b/arch/arm64/kernel/probes/uprobes.c new file mode 100644 index 000000000000..26c998534dca --- /dev/null +++ b/arch/arm64/kernel/probes/uprobes.c @@ -0,0 +1,216 @@ +/* + * Copyright (C) 2014-2016 Pratyush Anand <panand@redhat.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include <linux/highmem.h> +#include <linux/ptrace.h> +#include <linux/uprobes.h> +#include <asm/cacheflush.h> + +#include "decode-insn.h" + +#define UPROBE_INV_FAULT_CODE UINT_MAX + +void arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr, + void *src, unsigned long len) +{ + void *xol_page_kaddr = kmap_atomic(page); + void *dst = xol_page_kaddr + (vaddr & ~PAGE_MASK); + + /* Initialize the slot */ + memcpy(dst, src, len); + + /* flush caches (dcache/icache) */ + sync_icache_aliases(dst, len); + + kunmap_atomic(xol_page_kaddr); +} + +unsigned long uprobe_get_swbp_addr(struct pt_regs *regs) +{ + return instruction_pointer(regs); +} + +int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, + unsigned long addr) +{ + probe_opcode_t insn; + + /* TODO: Currently we do not support AARCH32 instruction probing */ + if (test_bit(TIF_32BIT, &mm->context.flags)) + return -ENOTSUPP; + else if (!IS_ALIGNED(addr, AARCH64_INSN_SIZE)) + return -EINVAL; + + insn = *(probe_opcode_t *)(&auprobe->insn[0]); + + switch (arm_probe_decode_insn(insn, &auprobe->api)) { + case INSN_REJECTED: + return -EINVAL; + + case INSN_GOOD_NO_SLOT: + auprobe->simulate = true; + break; + + default: + break; + } + + return 0; +} + +int arch_uprobe_pre_xol(struct arch_uprobe *auprobe, struct pt_regs *regs) +{ + struct uprobe_task *utask = current->utask; + + /* Initialize with an invalid fault code to detect if ol insn trapped */ + current->thread.fault_code = UPROBE_INV_FAULT_CODE; + + /* Instruction points to execute ol */ + instruction_pointer_set(regs, utask->xol_vaddr); + + user_enable_single_step(current); + + return 0; +} + +int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs) +{ + struct uprobe_task *utask = current->utask; + + WARN_ON_ONCE(current->thread.fault_code != UPROBE_INV_FAULT_CODE); + + /* Instruction points to execute next to breakpoint address */ + instruction_pointer_set(regs, utask->vaddr + 4); + + user_disable_single_step(current); + + return 0; +} +bool arch_uprobe_xol_was_trapped(struct task_struct *t) +{ + /* + * Between arch_uprobe_pre_xol and arch_uprobe_post_xol, if an xol + * insn itself is trapped, then detect the case with the help of + * invalid fault code which is being set in arch_uprobe_pre_xol + */ + if (t->thread.fault_code != UPROBE_INV_FAULT_CODE) + return true; + + return false; +} + +bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs) +{ + probe_opcode_t insn; + unsigned long addr; + + if (!auprobe->simulate) + return false; + + insn = *(probe_opcode_t *)(&auprobe->insn[0]); + addr = instruction_pointer(regs); + + if (auprobe->api.handler) + auprobe->api.handler(insn, addr, regs); + + return true; +} + +void arch_uprobe_abort_xol(struct arch_uprobe *auprobe, struct pt_regs *regs) +{ + struct uprobe_task *utask = current->utask; + + /* + * Task has received a fatal signal, so reset back to probbed + * address. + */ + instruction_pointer_set(regs, utask->vaddr); + + user_disable_single_step(current); +} + +bool arch_uretprobe_is_alive(struct return_instance *ret, enum rp_check ctx, + struct pt_regs *regs) +{ + /* + * If a simple branch instruction (B) was called for retprobed + * assembly label then return true even when regs->sp and ret->stack + * are same. It will ensure that cleanup and reporting of return + * instances corresponding to callee label is done when + * handle_trampoline for called function is executed. + */ + if (ctx == RP_CHECK_CHAIN_CALL) + return regs->sp <= ret->stack; + else + return regs->sp < ret->stack; +} + +unsigned long +arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr, + struct pt_regs *regs) +{ + unsigned long orig_ret_vaddr; + + orig_ret_vaddr = procedure_link_pointer(regs); + /* Replace the return addr with trampoline addr */ + procedure_link_pointer_set(regs, trampoline_vaddr); + + return orig_ret_vaddr; +} + +int arch_uprobe_exception_notify(struct notifier_block *self, + unsigned long val, void *data) +{ + return NOTIFY_DONE; +} + +static int uprobe_breakpoint_handler(struct pt_regs *regs, + unsigned int esr) +{ + if (user_mode(regs) && uprobe_pre_sstep_notifier(regs)) + return DBG_HOOK_HANDLED; + + return DBG_HOOK_ERROR; +} + +static int uprobe_single_step_handler(struct pt_regs *regs, + unsigned int esr) +{ + struct uprobe_task *utask = current->utask; + + if (user_mode(regs)) { + WARN_ON(utask && + (instruction_pointer(regs) != utask->xol_vaddr + 4)); + + if (uprobe_post_sstep_notifier(regs)) + return DBG_HOOK_HANDLED; + } + + return DBG_HOOK_ERROR; +} + +/* uprobe breakpoint handler hook */ +static struct break_hook uprobes_break_hook = { + .esr_mask = BRK64_ESR_MASK, + .esr_val = BRK64_ESR_UPROBES, + .fn = uprobe_breakpoint_handler, +}; + +/* uprobe single step handler hook */ +static struct step_hook uprobes_step_hook = { + .fn = uprobe_single_step_handler, +}; + +static int __init arch_init_uprobes(void) +{ + register_break_hook(&uprobes_break_hook); + register_step_hook(&uprobes_step_hook); + + return 0; +} + +device_initcall(arch_init_uprobes); diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index 404dd67080b9..c7b6de62f9d3 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -414,6 +414,9 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, } else { local_irq_enable(); + if (thread_flags & _TIF_UPROBE) + uprobe_notify_resume(regs); + if (thread_flags & _TIF_SIGPENDING) do_signal(regs); diff --git a/arch/arm64/mm/flush.c b/arch/arm64/mm/flush.c index 8377329d8c97..2d78d5a9b89f 100644 --- a/arch/arm64/mm/flush.c +++ b/arch/arm64/mm/flush.c @@ -32,7 +32,7 @@ void flush_cache_range(struct vm_area_struct *vma, unsigned long start, __flush_icache_all(); } -static void sync_icache_aliases(void *kaddr, unsigned long len) +void sync_icache_aliases(void *kaddr, unsigned long len) { unsigned long addr = (unsigned long)kaddr; |