diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/events/intel/core.c | 4 | ||||
| -rw-r--r-- | arch/x86/events/perf_event.h | 24 | ||||
| -rw-r--r-- | arch/x86/include/asm/kprobes.h | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/kprobes/common.h | 6 | ||||
| -rw-r--r-- | arch/x86/kernel/kprobes/core.c | 61 | ||||
| -rw-r--r-- | arch/x86/kernel/kprobes/ftrace.c | 32 | ||||
| -rw-r--r-- | arch/x86/kernel/kprobes/opt.c | 79 |
7 files changed, 131 insertions, 79 deletions
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c index 9fb9a1f1e47b..43445da30cea 100644 --- a/arch/x86/events/intel/core.c +++ b/arch/x86/events/intel/core.c @@ -2958,6 +2958,10 @@ static unsigned long intel_pmu_free_running_flags(struct perf_event *event) if (event->attr.use_clockid) flags &= ~PERF_SAMPLE_TIME; + if (!event->attr.exclude_kernel) + flags &= ~PERF_SAMPLE_REGS_USER; + if (event->attr.sample_regs_user & ~PEBS_REGS) + flags &= ~(PERF_SAMPLE_REGS_USER | PERF_SAMPLE_REGS_INTR); return flags; } diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h index 4196f81ec0e1..f7aaadf9331f 100644 --- a/arch/x86/events/perf_event.h +++ b/arch/x86/events/perf_event.h @@ -85,13 +85,15 @@ struct amd_nb { * Flags PEBS can handle without an PMI. * * TID can only be handled by flushing at context switch. + * REGS_USER can be handled for events limited to ring 3. * */ #define PEBS_FREERUNNING_FLAGS \ (PERF_SAMPLE_IP | PERF_SAMPLE_TID | PERF_SAMPLE_ADDR | \ PERF_SAMPLE_ID | PERF_SAMPLE_CPU | PERF_SAMPLE_STREAM_ID | \ PERF_SAMPLE_DATA_SRC | PERF_SAMPLE_IDENTIFIER | \ - PERF_SAMPLE_TRANSACTION | PERF_SAMPLE_PHYS_ADDR) + PERF_SAMPLE_TRANSACTION | PERF_SAMPLE_PHYS_ADDR | \ + PERF_SAMPLE_REGS_INTR | PERF_SAMPLE_REGS_USER) /* * A debug store configuration. @@ -110,6 +112,26 @@ struct debug_store { u64 pebs_event_reset[MAX_PEBS_EVENTS]; }; +#define PEBS_REGS \ + (PERF_REG_X86_AX | \ + PERF_REG_X86_BX | \ + PERF_REG_X86_CX | \ + PERF_REG_X86_DX | \ + PERF_REG_X86_DI | \ + PERF_REG_X86_SI | \ + PERF_REG_X86_SP | \ + PERF_REG_X86_BP | \ + PERF_REG_X86_IP | \ + PERF_REG_X86_FLAGS | \ + PERF_REG_X86_R8 | \ + PERF_REG_X86_R9 | \ + PERF_REG_X86_R10 | \ + PERF_REG_X86_R11 | \ + PERF_REG_X86_R12 | \ + PERF_REG_X86_R13 | \ + PERF_REG_X86_R14 | \ + PERF_REG_X86_R15) + /* * Per register state. */ diff --git a/arch/x86/include/asm/kprobes.h b/arch/x86/include/asm/kprobes.h index 6cf65437b5e5..9f2e3102e0bb 100644 --- a/arch/x86/include/asm/kprobes.h +++ b/arch/x86/include/asm/kprobes.h @@ -58,8 +58,8 @@ extern __visible kprobe_opcode_t optprobe_template_call[]; extern __visible kprobe_opcode_t optprobe_template_end[]; #define MAX_OPTIMIZED_LENGTH (MAX_INSN_SIZE + RELATIVE_ADDR_SIZE) #define MAX_OPTINSN_SIZE \ - (((unsigned long)&optprobe_template_end - \ - (unsigned long)&optprobe_template_entry) + \ + (((unsigned long)optprobe_template_end - \ + (unsigned long)optprobe_template_entry) + \ MAX_OPTIMIZED_LENGTH + RELATIVEJUMP_SIZE) extern const int kretprobe_blacklist_size; diff --git a/arch/x86/kernel/kprobes/common.h b/arch/x86/kernel/kprobes/common.h index 3fc0f9a794cb..595b56b37d27 100644 --- a/arch/x86/kernel/kprobes/common.h +++ b/arch/x86/kernel/kprobes/common.h @@ -84,11 +84,11 @@ extern unsigned long recover_probed_instruction(kprobe_opcode_t *buf, * Copy an instruction and adjust the displacement if the instruction * uses the %rip-relative addressing mode. */ -extern int __copy_instruction(u8 *dest, u8 *src, struct insn *insn); +extern int __copy_instruction(u8 *dest, u8 *src, u8 *real, struct insn *insn); /* Generate a relative-jump/call instruction */ -extern void synthesize_reljump(void *from, void *to); -extern void synthesize_relcall(void *from, void *to); +extern void synthesize_reljump(void *dest, void *from, void *to); +extern void synthesize_relcall(void *dest, void *from, void *to); #ifdef CONFIG_OPTPROBES extern int setup_detour_execution(struct kprobe *p, struct pt_regs *regs, int reenter); diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 0742491cbb73..bd36f3c33cd0 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -119,29 +119,29 @@ struct kretprobe_blackpoint kretprobe_blacklist[] = { const int kretprobe_blacklist_size = ARRAY_SIZE(kretprobe_blacklist); static nokprobe_inline void -__synthesize_relative_insn(void *from, void *to, u8 op) +__synthesize_relative_insn(void *dest, void *from, void *to, u8 op) { struct __arch_relative_insn { u8 op; s32 raddr; } __packed *insn; - insn = (struct __arch_relative_insn *)from; + insn = (struct __arch_relative_insn *)dest; insn->raddr = (s32)((long)(to) - ((long)(from) + 5)); insn->op = op; } /* Insert a jump instruction at address 'from', which jumps to address 'to'.*/ -void synthesize_reljump(void *from, void *to) +void synthesize_reljump(void *dest, void *from, void *to) { - __synthesize_relative_insn(from, to, RELATIVEJUMP_OPCODE); + __synthesize_relative_insn(dest, from, to, RELATIVEJUMP_OPCODE); } NOKPROBE_SYMBOL(synthesize_reljump); /* Insert a call instruction at address 'from', which calls address 'to'.*/ -void synthesize_relcall(void *from, void *to) +void synthesize_relcall(void *dest, void *from, void *to) { - __synthesize_relative_insn(from, to, RELATIVECALL_OPCODE); + __synthesize_relative_insn(dest, from, to, RELATIVECALL_OPCODE); } NOKPROBE_SYMBOL(synthesize_relcall); @@ -346,10 +346,11 @@ static int is_IF_modifier(kprobe_opcode_t *insn) /* * Copy an instruction with recovering modified instruction by kprobes * and adjust the displacement if the instruction uses the %rip-relative - * addressing mode. + * addressing mode. Note that since @real will be the final place of copied + * instruction, displacement must be adjust by @real, not @dest. * This returns the length of copied instruction, or 0 if it has an error. */ -int __copy_instruction(u8 *dest, u8 *src, struct insn *insn) +int __copy_instruction(u8 *dest, u8 *src, u8 *real, struct insn *insn) { kprobe_opcode_t buf[MAX_INSN_SIZE]; unsigned long recovered_insn = @@ -387,11 +388,11 @@ int __copy_instruction(u8 *dest, u8 *src, struct insn *insn) * have given. */ newdisp = (u8 *) src + (s64) insn->displacement.value - - (u8 *) dest; + - (u8 *) real; if ((s64) (s32) newdisp != newdisp) { pr_err("Kprobes error: new displacement does not fit into s32 (%llx)\n", newdisp); pr_err("\tSrc: %p, Dest: %p, old disp: %x\n", - src, dest, insn->displacement.value); + src, real, insn->displacement.value); return 0; } disp = (u8 *) dest + insn_offset_displacement(insn); @@ -402,20 +403,38 @@ int __copy_instruction(u8 *dest, u8 *src, struct insn *insn) } /* Prepare reljump right after instruction to boost */ -static void prepare_boost(struct kprobe *p, struct insn *insn) +static int prepare_boost(kprobe_opcode_t *buf, struct kprobe *p, + struct insn *insn) { + int len = insn->length; + if (can_boost(insn, p->addr) && - MAX_INSN_SIZE - insn->length >= RELATIVEJUMP_SIZE) { + MAX_INSN_SIZE - len >= RELATIVEJUMP_SIZE) { /* * These instructions can be executed directly if it * jumps back to correct address. */ - synthesize_reljump(p->ainsn.insn + insn->length, + synthesize_reljump(buf + len, p->ainsn.insn + len, p->addr + insn->length); + len += RELATIVEJUMP_SIZE; p->ainsn.boostable = true; } else { p->ainsn.boostable = false; } + + return len; +} + +/* Make page to RO mode when allocate it */ +void *alloc_insn_page(void) +{ + void *page; + + page = module_alloc(PAGE_SIZE); + if (page) + set_memory_ro((unsigned long)page & PAGE_MASK, 1); + + return page; } /* Recover page to RW mode before releasing it */ @@ -429,12 +448,11 @@ void free_insn_page(void *page) static int arch_copy_kprobe(struct kprobe *p) { struct insn insn; + kprobe_opcode_t buf[MAX_INSN_SIZE]; int len; - set_memory_rw((unsigned long)p->ainsn.insn & PAGE_MASK, 1); - /* Copy an instruction with recovering if other optprobe modifies it.*/ - len = __copy_instruction(p->ainsn.insn, p->addr, &insn); + len = __copy_instruction(buf, p->addr, p->ainsn.insn, &insn); if (!len) return -EINVAL; @@ -442,15 +460,16 @@ static int arch_copy_kprobe(struct kprobe *p) * __copy_instruction can modify the displacement of the instruction, * but it doesn't affect boostable check. */ - prepare_boost(p, &insn); - - set_memory_ro((unsigned long)p->ainsn.insn & PAGE_MASK, 1); + len = prepare_boost(buf, p, &insn); /* Check whether the instruction modifies Interrupt Flag or not */ - p->ainsn.if_modifier = is_IF_modifier(p->ainsn.insn); + p->ainsn.if_modifier = is_IF_modifier(buf); /* Also, displacement change doesn't affect the first byte */ - p->opcode = p->ainsn.insn[0]; + p->opcode = buf[0]; + + /* OK, write back the instruction(s) into ROX insn buffer */ + text_poke(p->ainsn.insn, buf, len); return 0; } diff --git a/arch/x86/kernel/kprobes/ftrace.c b/arch/x86/kernel/kprobes/ftrace.c index 041f7b6dfa0f..8dc0161cec8f 100644 --- a/arch/x86/kernel/kprobes/ftrace.c +++ b/arch/x86/kernel/kprobes/ftrace.c @@ -26,7 +26,7 @@ #include "common.h" static nokprobe_inline -int __skip_singlestep(struct kprobe *p, struct pt_regs *regs, +void __skip_singlestep(struct kprobe *p, struct pt_regs *regs, struct kprobe_ctlblk *kcb, unsigned long orig_ip) { /* @@ -41,33 +41,31 @@ int __skip_singlestep(struct kprobe *p, struct pt_regs *regs, __this_cpu_write(current_kprobe, NULL); if (orig_ip) regs->ip = orig_ip; - return 1; } int skip_singlestep(struct kprobe *p, struct pt_regs *regs, struct kprobe_ctlblk *kcb) { - if (kprobe_ftrace(p)) - return __skip_singlestep(p, regs, kcb, 0); - else - return 0; + if (kprobe_ftrace(p)) { + __skip_singlestep(p, regs, kcb, 0); + preempt_enable_no_resched(); + return 1; + } + return 0; } NOKPROBE_SYMBOL(skip_singlestep); -/* Ftrace callback handler for kprobes */ +/* Ftrace callback handler for kprobes -- called under preepmt disabed */ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *ops, struct pt_regs *regs) { struct kprobe *p; struct kprobe_ctlblk *kcb; - unsigned long flags; - - /* Disable irq for emulating a breakpoint and avoiding preempt */ - local_irq_save(flags); + /* Preempt is disabled by ftrace */ p = get_kprobe((kprobe_opcode_t *)ip); if (unlikely(!p) || kprobe_disabled(p)) - goto end; + return; kcb = get_kprobe_ctlblk(); if (kprobe_running()) { @@ -77,17 +75,19 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, /* Kprobe handler expects regs->ip = ip + 1 as breakpoint hit */ regs->ip = ip + sizeof(kprobe_opcode_t); + /* To emulate trap based kprobes, preempt_disable here */ + preempt_disable(); __this_cpu_write(current_kprobe, p); kcb->kprobe_status = KPROBE_HIT_ACTIVE; - if (!p->pre_handler || !p->pre_handler(p, regs)) + if (!p->pre_handler || !p->pre_handler(p, regs)) { __skip_singlestep(p, regs, kcb, orig_ip); + preempt_enable_no_resched(); + } /* * If pre_handler returns !0, it sets regs->ip and - * resets current kprobe. + * resets current kprobe, and keep preempt count +1. */ } -end: - local_irq_restore(flags); } NOKPROBE_SYMBOL(kprobe_ftrace_handler); diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c index 4f98aad38237..e941136e24d8 100644 --- a/arch/x86/kernel/kprobes/opt.c +++ b/arch/x86/kernel/kprobes/opt.c @@ -142,11 +142,11 @@ void optprobe_template_func(void); STACK_FRAME_NON_STANDARD(optprobe_template_func); #define TMPL_MOVE_IDX \ - ((long)&optprobe_template_val - (long)&optprobe_template_entry) + ((long)optprobe_template_val - (long)optprobe_template_entry) #define TMPL_CALL_IDX \ - ((long)&optprobe_template_call - (long)&optprobe_template_entry) + ((long)optprobe_template_call - (long)optprobe_template_entry) #define TMPL_END_IDX \ - ((long)&optprobe_template_end - (long)&optprobe_template_entry) + ((long)optprobe_template_end - (long)optprobe_template_entry) #define INT3_SIZE sizeof(kprobe_opcode_t) @@ -154,17 +154,15 @@ STACK_FRAME_NON_STANDARD(optprobe_template_func); static void optimized_callback(struct optimized_kprobe *op, struct pt_regs *regs) { - struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); - unsigned long flags; - /* This is possible if op is under delayed unoptimizing */ if (kprobe_disabled(&op->kp)) return; - local_irq_save(flags); + preempt_disable(); if (kprobe_running()) { kprobes_inc_nmissed_count(&op->kp); } else { + struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); /* Save skipped registers */ #ifdef CONFIG_X86_64 regs->cs = __KERNEL_CS; @@ -180,17 +178,17 @@ optimized_callback(struct optimized_kprobe *op, struct pt_regs *regs) opt_pre_handler(&op->kp, regs); __this_cpu_write(current_kprobe, NULL); } - local_irq_restore(flags); + preempt_enable_no_resched(); } NOKPROBE_SYMBOL(optimized_callback); -static int copy_optimized_instructions(u8 *dest, u8 *src) +static int copy_optimized_instructions(u8 *dest, u8 *src, u8 *real) { struct insn insn; int len = 0, ret; while (len < RELATIVEJUMP_SIZE) { - ret = __copy_instruction(dest + len, src + len, &insn); + ret = __copy_instruction(dest + len, src + len, real, &insn); if (!ret || !can_boost(&insn, src + len)) return -EINVAL; len += ret; @@ -343,57 +341,66 @@ void arch_remove_optimized_kprobe(struct optimized_kprobe *op) int arch_prepare_optimized_kprobe(struct optimized_kprobe *op, struct kprobe *__unused) { - u8 *buf; - int ret; + u8 *buf = NULL, *slot; + int ret, len; long rel; if (!can_optimize((unsigned long)op->kp.addr)) return -EILSEQ; - op->optinsn.insn = get_optinsn_slot(); - if (!op->optinsn.insn) + buf = kzalloc(MAX_OPTINSN_SIZE, GFP_KERNEL); + if (!buf) return -ENOMEM; + op->optinsn.insn = slot = get_optinsn_slot(); + if (!slot) { + ret = -ENOMEM; + goto out; + } + /* * Verify if the address gap is in 2GB range, because this uses * a relative jump. */ - rel = (long)op->optinsn.insn - (long)op->kp.addr + RELATIVEJUMP_SIZE; + rel = (long)slot - (long)op->kp.addr + RELATIVEJUMP_SIZE; if (abs(rel) > 0x7fffffff) { - __arch_remove_optimized_kprobe(op, 0); - return -ERANGE; + ret = -ERANGE; + goto err; } - buf = (u8 *)op->optinsn.insn; - set_memory_rw((unsigned long)buf & PAGE_MASK, 1); + /* Copy arch-dep-instance from template */ + memcpy(buf, optprobe_template_entry, TMPL_END_IDX); /* Copy instructions into the out-of-line buffer */ - ret = copy_optimized_instructions(buf + TMPL_END_IDX, op->kp.addr); - if (ret < 0) { - __arch_remove_optimized_kprobe(op, 0); - return ret; - } + ret = copy_optimized_instructions(buf + TMPL_END_IDX, op->kp.addr, + slot + TMPL_END_IDX); + if (ret < 0) + goto err; op->optinsn.size = ret; - - /* Copy arch-dep-instance from template */ - memcpy(buf, &optprobe_template_entry, TMPL_END_IDX); + len = TMPL_END_IDX + op->optinsn.size; /* Set probe information */ synthesize_set_arg1(buf + TMPL_MOVE_IDX, (unsigned long)op); /* Set probe function call */ - synthesize_relcall(buf + TMPL_CALL_IDX, optimized_callback); + synthesize_relcall(buf + TMPL_CALL_IDX, + slot + TMPL_CALL_IDX, optimized_callback); /* Set returning jmp instruction at the tail of out-of-line buffer */ - synthesize_reljump(buf + TMPL_END_IDX + op->optinsn.size, + synthesize_reljump(buf + len, slot + len, (u8 *)op->kp.addr + op->optinsn.size); - - set_memory_ro((unsigned long)buf & PAGE_MASK, 1); - - flush_icache_range((unsigned long) buf, - (unsigned long) buf + TMPL_END_IDX + - op->optinsn.size + RELATIVEJUMP_SIZE); - return 0; + len += RELATIVEJUMP_SIZE; + + /* We have to use text_poke for instuction buffer because it is RO */ + text_poke(slot, buf, len); + ret = 0; +out: + kfree(buf); + return ret; + +err: + __arch_remove_optimized_kprobe(op, 0); + goto out; } /* |