diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/events/core.c | 49 | ||||
| -rw-r--r-- | kernel/events/uprobes.c | 278 | ||||
| -rw-r--r-- | kernel/trace/trace.c | 12 | ||||
| -rw-r--r-- | kernel/trace/trace_event_perf.c | 7 | ||||
| -rw-r--r-- | kernel/trace/trace_kprobe.c | 412 | ||||
| -rw-r--r-- | kernel/trace/trace_probe.c | 672 | ||||
| -rw-r--r-- | kernel/trace/trace_probe.h | 289 | ||||
| -rw-r--r-- | kernel/trace/trace_probe_tmpl.h | 216 | ||||
| -rw-r--r-- | kernel/trace/trace_stack.c | 2 | ||||
| -rw-r--r-- | kernel/trace/trace_uprobe.c | 255 |
10 files changed, 1261 insertions, 931 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 5a97f34bc14c..8c490130c4fb 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -8376,30 +8376,39 @@ static struct pmu perf_tracepoint = { * * PERF_PROBE_CONFIG_IS_RETPROBE if set, create kretprobe/uretprobe * if not set, create kprobe/uprobe + * + * The following values specify a reference counter (or semaphore in the + * terminology of tools like dtrace, systemtap, etc.) Userspace Statically + * Defined Tracepoints (USDT). Currently, we use 40 bit for the offset. + * + * PERF_UPROBE_REF_CTR_OFFSET_BITS # of bits in config as th offset + * PERF_UPROBE_REF_CTR_OFFSET_SHIFT # of bits to shift left */ enum perf_probe_config { PERF_PROBE_CONFIG_IS_RETPROBE = 1U << 0, /* [k,u]retprobe */ + PERF_UPROBE_REF_CTR_OFFSET_BITS = 32, + PERF_UPROBE_REF_CTR_OFFSET_SHIFT = 64 - PERF_UPROBE_REF_CTR_OFFSET_BITS, }; PMU_FORMAT_ATTR(retprobe, "config:0"); +#endif -static struct attribute *probe_attrs[] = { +#ifdef CONFIG_KPROBE_EVENTS +static struct attribute *kprobe_attrs[] = { &format_attr_retprobe.attr, NULL, }; -static struct attribute_group probe_format_group = { +static struct attribute_group kprobe_format_group = { .name = "format", - .attrs = probe_attrs, + .attrs = kprobe_attrs, }; -static const struct attribute_group *probe_attr_groups[] = { - &probe_format_group, +static const struct attribute_group *kprobe_attr_groups[] = { + &kprobe_format_group, NULL, }; -#endif -#ifdef CONFIG_KPROBE_EVENTS static int perf_kprobe_event_init(struct perf_event *event); static struct pmu perf_kprobe = { .task_ctx_nr = perf_sw_context, @@ -8409,7 +8418,7 @@ static struct pmu perf_kprobe = { .start = perf_swevent_start, .stop = perf_swevent_stop, .read = perf_swevent_read, - .attr_groups = probe_attr_groups, + .attr_groups = kprobe_attr_groups, }; static int perf_kprobe_event_init(struct perf_event *event) @@ -8441,6 +8450,24 @@ static int perf_kprobe_event_init(struct perf_event *event) #endif /* CONFIG_KPROBE_EVENTS */ #ifdef CONFIG_UPROBE_EVENTS +PMU_FORMAT_ATTR(ref_ctr_offset, "config:32-63"); + +static struct attribute *uprobe_attrs[] = { + &format_attr_retprobe.attr, + &format_attr_ref_ctr_offset.attr, + NULL, +}; + +static struct attribute_group uprobe_format_group = { + .name = "format", + .attrs = uprobe_attrs, +}; + +static const struct attribute_group *uprobe_attr_groups[] = { + &uprobe_format_group, + NULL, +}; + static int perf_uprobe_event_init(struct perf_event *event); static struct pmu perf_uprobe = { .task_ctx_nr = perf_sw_context, @@ -8450,12 +8477,13 @@ static struct pmu perf_uprobe = { .start = perf_swevent_start, .stop = perf_swevent_stop, .read = perf_swevent_read, - .attr_groups = probe_attr_groups, + .attr_groups = uprobe_attr_groups, }; static int perf_uprobe_event_init(struct perf_event *event) { int err; + unsigned long ref_ctr_offset; bool is_retprobe; if (event->attr.type != perf_uprobe.type) @@ -8471,7 +8499,8 @@ static int perf_uprobe_event_init(struct perf_event *event) return -EOPNOTSUPP; is_retprobe = event->attr.config & PERF_PROBE_CONFIG_IS_RETPROBE; - err = perf_uprobe_init(event, is_retprobe); + ref_ctr_offset = event->attr.config >> PERF_UPROBE_REF_CTR_OFFSET_SHIFT; + err = perf_uprobe_init(event, ref_ctr_offset, is_retprobe); if (err) return err; diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 2bf792d22087..96d4bee83489 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -73,6 +73,7 @@ struct uprobe { struct uprobe_consumer *consumers; struct inode *inode; /* Also hold a ref to inode */ loff_t offset; + loff_t ref_ctr_offset; unsigned long flags; /* @@ -88,6 +89,15 @@ struct uprobe { struct arch_uprobe arch; }; +struct delayed_uprobe { + struct list_head list; + struct uprobe *uprobe; + struct mm_struct *mm; +}; + +static DEFINE_MUTEX(delayed_uprobe_lock); +static LIST_HEAD(delayed_uprobe_list); + /* * Execute out of line area: anonymous executable mapping installed * by the probed task to execute the copy of the original instruction @@ -282,6 +292,166 @@ static int verify_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t return 1; } +static struct delayed_uprobe * +delayed_uprobe_check(struct uprobe *uprobe, struct mm_struct *mm) +{ + struct delayed_uprobe *du; + + list_for_each_entry(du, &delayed_uprobe_list, list) + if (du->uprobe == uprobe && du->mm == mm) + return du; + return NULL; +} + +static int delayed_uprobe_add(struct uprobe *uprobe, struct mm_struct *mm) +{ + struct delayed_uprobe *du; + + if (delayed_uprobe_check(uprobe, mm)) + return 0; + + du = kzalloc(sizeof(*du), GFP_KERNEL); + if (!du) + return -ENOMEM; + + du->uprobe = uprobe; + du->mm = mm; + list_add(&du->list, &delayed_uprobe_list); + return 0; +} + +static void delayed_uprobe_delete(struct delayed_uprobe *du) +{ + if (WARN_ON(!du)) + return; + list_del(&du->list); + kfree(du); +} + +static void delayed_uprobe_remove(struct uprobe *uprobe, struct mm_struct *mm) +{ + struct list_head *pos, *q; + struct delayed_uprobe *du; + + if (!uprobe && !mm) + return; + + list_for_each_safe(pos, q, &delayed_uprobe_list) { + du = list_entry(pos, struct delayed_uprobe, list); + + if (uprobe && du->uprobe != uprobe) + continue; + if (mm && du->mm != mm) + continue; + + delayed_uprobe_delete(du); + } +} + +static bool valid_ref_ctr_vma(struct uprobe *uprobe, + struct vm_area_struct *vma) +{ + unsigned long vaddr = offset_to_vaddr(vma, uprobe->ref_ctr_offset); + + return uprobe->ref_ctr_offset && + vma->vm_file && + file_inode(vma->vm_file) == uprobe->inode && + (vma->vm_flags & (VM_WRITE|VM_SHARED)) == VM_WRITE && + vma->vm_start <= vaddr && + vma->vm_end > vaddr; +} + +static struct vm_area_struct * +find_ref_ctr_vma(struct uprobe *uprobe, struct mm_struct *mm) +{ + struct vm_area_struct *tmp; + + for (tmp = mm->mmap; tmp; tmp = tmp->vm_next) + if (valid_ref_ctr_vma(uprobe, tmp)) + return tmp; + + return NULL; +} + +static int +__update_ref_ctr(struct mm_struct *mm, unsigned long vaddr, short d) +{ + void *kaddr; + struct page *page; + struct vm_area_struct *vma; + int ret; + short *ptr; + + if (!vaddr || !d) + return -EINVAL; + + ret = get_user_pages_remote(NULL, mm, vaddr, 1, + FOLL_WRITE, &page, &vma, NULL); + if (unlikely(ret <= 0)) { + /* + * We are asking for 1 page. If get_user_pages_remote() fails, + * it may return 0, in that case we have to return error. + */ + return ret == 0 ? -EBUSY : ret; + } + + kaddr = kmap_atomic(page); + ptr = kaddr + (vaddr & ~PAGE_MASK); + + if (unlikely(*ptr + d < 0)) { + pr_warn("ref_ctr going negative. vaddr: 0x%lx, " + "curr val: %d, delta: %d\n", vaddr, *ptr, d); + ret = -EINVAL; + goto out; + } + + *ptr += d; + ret = 0; +out: + kunmap_atomic(kaddr); + put_page(page); + return ret; +} + +static void update_ref_ctr_warn(struct uprobe *uprobe, + struct mm_struct *mm, short d) +{ + pr_warn("ref_ctr %s failed for inode: 0x%lx offset: " + "0x%llx ref_ctr_offset: 0x%llx of mm: 0x%pK\n", + d > 0 ? "increment" : "decrement", uprobe->inode->i_ino, + (unsigned long long) uprobe->offset, + (unsigned long long) uprobe->ref_ctr_offset, mm); +} + +static int update_ref_ctr(struct uprobe *uprobe, struct mm_struct *mm, + short d) +{ + struct vm_area_struct *rc_vma; + unsigned long rc_vaddr; + int ret = 0; + + rc_vma = find_ref_ctr_vma(uprobe, mm); + + if (rc_vma) { + rc_vaddr = offset_to_vaddr(rc_vma, uprobe->ref_ctr_offset); + ret = __update_ref_ctr(mm, rc_vaddr, d); + if (ret) + update_ref_ctr_warn(uprobe, mm, d); + + if (d > 0) + return ret; + } + + mutex_lock(&delayed_uprobe_lock); + if (d > 0) + ret = delayed_uprobe_add(uprobe, mm); + else + delayed_uprobe_remove(uprobe, mm); + mutex_unlock(&delayed_uprobe_lock); + + return ret; +} + /* * NOTE: * Expect the breakpoint instruction to be the smallest size instruction for @@ -302,9 +472,13 @@ static int verify_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr, uprobe_opcode_t opcode) { + struct uprobe *uprobe; struct page *old_page, *new_page; struct vm_area_struct *vma; - int ret; + int ret, is_register, ref_ctr_updated = 0; + + is_register = is_swbp_insn(&opcode); + uprobe = container_of(auprobe, struct uprobe, arch); retry: /* Read the page with vaddr into memory */ @@ -317,6 +491,15 @@ retry: if (ret <= 0) goto put_old; + /* We are going to replace instruction, update ref_ctr. */ + if (!ref_ctr_updated && uprobe->ref_ctr_offset) { + ret = update_ref_ctr(uprobe, mm, is_register ? 1 : -1); + if (ret) + goto put_old; + + ref_ctr_updated = 1; + } + ret = anon_vma_prepare(vma); if (ret) goto put_old; @@ -337,6 +520,11 @@ put_old: if (unlikely(ret == -EAGAIN)) goto retry; + + /* Revert back reference counter if instruction update failed. */ + if (ret && is_register && ref_ctr_updated) + update_ref_ctr(uprobe, mm, -1); + return ret; } @@ -378,8 +566,15 @@ static struct uprobe *get_uprobe(struct uprobe *uprobe) static void put_uprobe(struct uprobe *uprobe) { - if (atomic_dec_and_test(&uprobe->ref)) + if (atomic_dec_and_test(&uprobe->ref)) { + /* + * If application munmap(exec_vma) before uprobe_unregister() + * gets called, we don't get a chance to remove uprobe from + * delayed_uprobe_list from remove_breakpoint(). Do it here. + */ + delayed_uprobe_remove(uprobe, NULL); kfree(uprobe); + } } static int match_uprobe(struct uprobe *l, struct uprobe *r) @@ -484,7 +679,18 @@ static struct uprobe *insert_uprobe(struct uprobe *uprobe) return u; } -static struct uprobe *alloc_uprobe(struct inode *inode, loff_t offset) +static void +ref_ctr_mismatch_warn(struct uprobe *cur_uprobe, struct uprobe *uprobe) +{ + pr_warn("ref_ctr_offset mismatch. inode: 0x%lx offset: 0x%llx " + "ref_ctr_offset(old): 0x%llx ref_ctr_offset(new): 0x%llx\n", + uprobe->inode->i_ino, (unsigned long long) uprobe->offset, + (unsigned long long) cur_uprobe->ref_ctr_offset, + (unsigned long long) uprobe->ref_ctr_offset); +} + +static struct uprobe *alloc_uprobe(struct inode *inode, loff_t offset, + loff_t ref_ctr_offset) { struct uprobe *uprobe, *cur_uprobe; @@ -494,6 +700,7 @@ static struct uprobe *alloc_uprobe(struct inode *inode, loff_t offset) uprobe->inode = inode; uprobe->offset = offset; + uprobe->ref_ctr_offset = ref_ctr_offset; init_rwsem(&uprobe->register_rwsem); init_rwsem(&uprobe->consumer_rwsem); @@ -501,6 +708,12 @@ static struct uprobe *alloc_uprobe(struct inode *inode, loff_t offset) cur_uprobe = insert_uprobe(uprobe); /* a uprobe exists for this inode:offset combination */ if (cur_uprobe) { + if (cur_uprobe->ref_ctr_offset != uprobe->ref_ctr_offset) { + ref_ctr_mismatch_warn(cur_uprobe, uprobe); + put_uprobe(cur_uprobe); + kfree(uprobe); + return ERR_PTR(-EINVAL); + } kfree(uprobe); uprobe = cur_uprobe; } @@ -895,7 +1108,7 @@ EXPORT_SYMBOL_GPL(uprobe_unregister); * else return 0 (success) */ static int __uprobe_register(struct inode *inode, loff_t offset, - struct uprobe_consumer *uc) + loff_t ref_ctr_offset, struct uprobe_consumer *uc) { struct uprobe *uprobe; int ret; @@ -912,9 +1125,12 @@ static int __uprobe_register(struct inode *inode, loff_t offset, return -EINVAL; retry: - uprobe = alloc_uprobe(inode, offset); + uprobe = alloc_uprobe(inode, offset, ref_ctr_offset); if (!uprobe) return -ENOMEM; + if (IS_ERR(uprobe)) + return PTR_ERR(uprobe); + /* * We can race with uprobe_unregister()->delete_uprobe(). * Check uprobe_is_active() and retry if it is false. @@ -938,10 +1154,17 @@ static int __uprobe_register(struct inode *inode, loff_t offset, int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *uc) { - return __uprobe_register(inode, offset, uc); + return __uprobe_register(inode, offset, 0, uc); } EXPORT_SYMBOL_GPL(uprobe_register); +int uprobe_register_refctr(struct inode *inode, loff_t offset, + loff_t ref_ctr_offset, struct uprobe_consumer *uc) +{ + return __uprobe_register(inode, offset, ref_ctr_offset, uc); +} +EXPORT_SYMBOL_GPL(uprobe_register_refctr); + /* * uprobe_apply - unregister an already registered probe. * @inode: the file in which the probe has to be removed. @@ -1060,6 +1283,35 @@ static void build_probe_list(struct inode *inode, spin_unlock(&uprobes_treelock); } +/* @vma contains reference counter, not the probed instruction. */ +static int delayed_ref_ctr_inc(struct vm_area_struct *vma) +{ + struct list_head *pos, *q; + struct delayed_uprobe *du; + unsigned long vaddr; + int ret = 0, err = 0; + + mutex_lock(&delayed_uprobe_lock); + list_for_each_safe(pos, q, &delayed_uprobe_list) { + du = list_entry(pos, struct delayed_uprobe, list); + + if (du->mm != vma->vm_mm || + !valid_ref_ctr_vma(du->uprobe, vma)) + continue; + + vaddr = offset_to_vaddr(vma, du->uprobe->ref_ctr_offset); + ret = __update_ref_ctr(vma->vm_mm, vaddr, 1); + if (ret) { + update_ref_ctr_warn(du->uprobe, vma->vm_mm, 1); + if (!err) + err = ret; + } + delayed_uprobe_delete(du); + } + mutex_unlock(&delayed_uprobe_lock); + return err; +} + /* * Called from mmap_region/vma_adjust with mm->mmap_sem acquired. * @@ -1072,7 +1324,15 @@ int uprobe_mmap(struct vm_area_struct *vma) struct uprobe *uprobe, *u; struct inode *inode; - if (no_uprobe_events() || !valid_vma(vma, true)) + if (no_uprobe_events()) + return 0; + + if (vma->vm_file && + (vma->vm_flags & (VM_WRITE|VM_SHARED)) == VM_WRITE && + test_bit(MMF_HAS_UPROBES, &vma->vm_mm->flags)) + delayed_ref_ctr_inc(vma); + + if (!valid_vma(vma, true)) return 0; inode = file_inode(vma->vm_file); @@ -1246,6 +1506,10 @@ void uprobe_clear_state(struct mm_struct *mm) { struct xol_area *area = mm->uprobes_state.xol_area; + mutex_lock(&delayed_uprobe_lock); + delayed_uprobe_remove(NULL, mm); + mutex_unlock(&delayed_uprobe_lock); + if (!area) return; diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index bf6f1d70484d..ff1c4b20cd0a 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2727,6 +2727,7 @@ void trace_dump_stack(int skip) __ftrace_trace_stack(global_trace.trace_buffer.buffer, flags, skip, preempt_count(), NULL); } +EXPORT_SYMBOL_GPL(trace_dump_stack); static DEFINE_PER_CPU(int, user_stack_count); @@ -4621,13 +4622,18 @@ static const char readme_msg[] = "place (kretprobe): [<module>:]<symbol>[+<offset>]|<memaddr>\n" #endif #ifdef CONFIG_UPROBE_EVENTS - "\t place: <path>:<offset>\n" + " place (uprobe): <path>:<offset>[(ref_ctr_offset)]\n" #endif "\t args: <name>=fetcharg[:type]\n" "\t fetcharg: %<register>, @<address>, @<symbol>[+|-<offset>],\n" +#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API + "\t $stack<index>, $stack, $retval, $comm, $arg<N>\n" +#else "\t $stack<index>, $stack, $retval, $comm\n" - "\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, string,\n" - "\t b<bit-width>@<bit-offset>/<container-size>\n" +#endif + "\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, string, symbol,\n" + "\t b<bit-width>@<bit-offset>/<container-size>,\n" + "\t <type>\\[<array-size>\\]\n" #endif " events/\t\t- Directory containing all trace event subsystems:\n" " enable\t\t- Write 0/1 to enable/disable tracing of all events\n" diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index 69a3fe926e8c..76217bbef815 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -290,7 +290,8 @@ void perf_kprobe_destroy(struct perf_event *p_event) #endif /* CONFIG_KPROBE_EVENTS */ #ifdef CONFIG_UPROBE_EVENTS -int perf_uprobe_init(struct perf_event *p_event, bool is_retprobe) +int perf_uprobe_init(struct perf_event *p_event, + unsigned long ref_ctr_offset, bool is_retprobe) { int ret; char *path = NULL; @@ -312,8 +313,8 @@ int perf_uprobe_init(struct perf_event *p_event, bool is_retprobe) goto out; } - tp_event = create_local_trace_uprobe( - path, p_event->attr.probe_offset, is_retprobe); + tp_event = create_local_trace_uprobe(path, p_event->attr.probe_offset, + ref_ctr_offset, is_retprobe); if (IS_ERR(tp_event)) { ret = PTR_ERR(tp_event); goto out; diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index c30032367aab..fec67188c4d2 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -14,6 +14,7 @@ #include "trace_kprobe_selftest.h" #include "trace_probe.h" +#include "trace_probe_tmpl.h" #define KPROBE_EVENT_SYSTEM "kprobes" #define KRETPROBE_MAXACTIVE_MAX 4096 @@ -61,9 +62,23 @@ static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk, return strncmp(mod->name, name, len) == 0 && name[len] == ':'; } -static nokprobe_inline bool trace_kprobe_is_on_module(struct trace_kprobe *tk) +static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk) { - return !!strchr(trace_kprobe_symbol(tk), ':'); + char *p; + bool ret; + + if (!tk->symbol) + return false; + p = strchr(tk->symbol, ':'); + if (!p) + return true; + *p = '\0'; + mutex_lock(&module_mutex); + ret = !!find_module(tk->symbol); + mutex_unlock(&module_mutex); + *p = ':'; + + return ret; } static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk) @@ -120,184 +135,6 @@ static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); static int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs); -/* Memory fetching by symbol */ -struct symbol_cache { - char *symbol; - long offset; - unsigned long addr; -}; - -unsigned long update_symbol_cache(struct symbol_cache *sc) -{ - sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol); - - if (sc->addr) - sc->addr += sc->offset; - - return sc->addr; -} - -void free_symbol_cache(struct symbol_cache *sc) -{ - kfree(sc->symbol); - kfree(sc); -} - -struct symbol_cache *alloc_symbol_cache(const char *sym, long offset) -{ - struct symbol_cache *sc; - - if (!sym || strlen(sym) == 0) - return NULL; - - sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL); - if (!sc) - return NULL; - - sc->symbol = kstrdup(sym, GFP_KERNEL); - if (!sc->symbol) { - kfree(sc); - return NULL; - } - sc->offset = offset; - update_symbol_cache(sc); - - return sc; -} - -/* - * Kprobes-specific fetch functions - */ -#define DEFINE_FETCH_stack(type) \ -static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \ - void *offset, void *dest) \ -{ \ - *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \ - (unsigned int)((unsigned long)offset)); \ -} \ -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(stack, type)); - -DEFINE_BASIC_FETCH_FUNCS(stack) -/* No string on the stack entry */ -#define fetch_stack_string NULL -#define fetch_stack_string_size NULL - -#define DEFINE_FETCH_memory(type) \ -static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \ - void *addr, void *dest) \ -{ \ - type retval; \ - if (probe_kernel_address(addr, retval)) \ - *(type *)dest = 0; \ - else \ - *(type *)dest = retval; \ -} \ -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, type)); - -DEFINE_BASIC_FETCH_FUNCS(memory) -/* - * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max - * length and relative data location. - */ -static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, - void *addr, void *dest) -{ - int maxlen = get_rloc_len(*(u32 *)dest); - u8 *dst = get_rloc_data(dest); - long ret; - - if (!maxlen) - return; - - /* - * Try to get string again, since the string can be changed while - * probing. - */ - ret = strncpy_from_unsafe(dst, addr, maxlen); - - if (ret < 0) { /* Failed to fetch string */ - dst[0] = '\0'; - *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest)); - } else { - *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest)); - } -} -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string)); - -/* Return the length of string -- including null terminal byte */ -static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, - void *addr, void *dest) -{ - mm_segment_t old_fs; - int ret, len = 0; - u8 c; - - old_fs = get_fs(); - set_fs(KERNEL_DS); - pagefault_disable(); - - do { - ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1); - len++; - } while (c && ret == 0 && len < MAX_STRING_SIZE); - - pagefault_enable(); - set_fs(old_fs); - - if (ret < 0) /* Failed to check the length */ - *(u32 *)dest = 0; - else - *(u32 *)dest = len; -} -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string_size)); - -#define DEFINE_FETCH_symbol(type) \ -void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs, void *data, void *dest)\ -{ \ - struct symbol_cache *sc = data; \ - if (sc->addr) \ - fetch_memory_##type(regs, (void *)sc->addr, dest); \ - else \ - *(type *)dest = 0; \ -} \ -NOKPROBE_SYMBOL(FETCH_FUNC_NAME(symbol, type)); - -DEFINE_BASIC_FETCH_FUNCS(symbol) -DEFINE_FETCH_symbol(string) -DEFINE_FETCH_symbol(string_size) - -/* kprobes don't support file_offset fetch methods */ -#define fetch_file_offset_u8 NULL -#define fetch_file_offset_u16 NULL -#define fetch_file_offset_u32 NULL -#define fetch_file_offset_u64 NULL -#define fetch_file_offset_string NULL -#define fetch_file_offset_string_size NULL - -/* Fetch type information table */ -static const struct fetch_type kprobes_fetch_type_table[] = { - /* Special types */ - [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string, - sizeof(u32), 1, "__data_loc char[]"), - [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32, - string_size, sizeof(u32), 0, "u32"), - /* Basic types */ - ASSIGN_FETCH_TYPE(u8, u8, 0), - ASSIGN_FETCH_TYPE(u16, u16, 0), - ASSIGN_FETCH_TYPE(u32, u32, 0), - ASSIGN_FETCH_TYPE(u64, u64, 0), - ASSIGN_FETCH_TYPE(s8, u8, 1), - ASSIGN_FETCH_TYPE(s16, u16, 1), - ASSIGN_FETCH_TYPE(s32, u32, 1), - ASSIGN_FETCH_TYPE(s64, u64, 1), - ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0), - ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0), - ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0), - ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0), - - ASSIGN_FETCH_TYPE_END -}; - /* * Allocate new trace_probe and initialize it (including kprobes). */ @@ -540,8 +377,11 @@ static int __register_trace_kprobe(struct trace_kprobe *tk) return -EINVAL; } - for (i = 0; i < tk->tp.nr_args; i++) - traceprobe_update_arg(&tk->tp.args[i]); + for (i = 0; i < tk->tp.nr_args; i++) { + ret = traceprobe_update_arg(&tk->tp.args[i]); + if (ret) + return ret; + } /* Set/clear disabled flag according to tp->flag */ if (trace_probe_is_enabled(&tk->tp)) @@ -554,19 +394,13 @@ static int __register_trace_kprobe(struct trace_kprobe *tk) else ret = register_kprobe(&tk->rp.kp); - if (ret == 0) + if (ret == 0) { tk->tp.flags |= TP_FLAG_REGISTERED; - else { - if (ret == -ENOENT && trace_kprobe_is_on_module(tk)) { - pr_warn("This probe might be able to register after target module is loaded. Continue.\n"); - ret = 0; - } else if (ret == -EILSEQ) { - pr_warn("Probing address(0x%p) is not an instruction boundary.\n", - tk->rp.kp.addr); - ret = -EINVAL; - } + } else if (ret == -EILSEQ) { + pr_warn("Probing address(0x%p) is not an instruction boundary.\n", + tk->rp.kp.addr); + ret = -EINVAL; } - return ret; } @@ -629,6 +463,11 @@ static int register_trace_kprobe(struct trace_kprobe *tk) /* Register k*probe */ ret = __register_trace_kprobe(tk); + if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) { + pr_warn("This probe might be able to register after target module is loaded. Continue.\n"); + ret = 0; + } + if (ret < 0) unregister_kprobe_event(tk); else @@ -713,13 +552,15 @@ static int create_trace_kprobe(int argc, char **argv) long offset = 0; void *addr = NULL; char buf[MAX_EVENT_NAME_LEN]; + unsigned int flags = TPARG_FL_KERNEL; /* argc must be >= 1 */ if (argv[0][0] == 'p') is_return = false; - else if (argv[0][0] == 'r') + else if (argv[0][0] == 'r') { is_return = true; - else if (argv[0][0] == '-') + flags |= TPARG_FL_RETURN; + } else if (argv[0][0] == '-') is_delete = true; else { pr_info("Probe definition must be started with 'p', 'r' or" @@ -749,10 +590,13 @@ static int create_trace_kprobe(int argc, char **argv) } if (event) { - if (strchr(event, '/')) { + char *slash; + + slash = strchr(event, '/'); + if (slash) { group = event; - event = strchr(group, '/') + 1; - event[-1] = '\0'; + event = slash + 1; + slash[0] = '\0'; if (strlen(group) == 0) { pr_info("Group name is not specified\n"); return -EINVAL; @@ -802,8 +646,9 @@ static int create_trace_kprobe(int argc, char **argv) pr_info("Failed to parse either an address or a symbol.\n"); return ret; } - if (offset && is_return && - !kprobe_on_func_entry(NULL, symbol, offset)) { + if (kprobe_on_func_entry(NULL, symbol, offset)) + flags |= TPARG_FL_FENTRY; + if (offset && is_return && !(flags & TPARG_FL_FENTRY)) { pr_info("Given offset is not valid for return probe.\n"); return -EINVAL; } @@ -873,8 +718,7 @@ static int create_trace_kprobe(int argc, char **argv) /* Parse fetch argument */ ret = traceprobe_parse_probe_arg(arg, &tk->tp.size, parg, - is_return, true, - kprobes_fetch_type_table); + flags); if (ret) { pr_info("Parse error at argument[%d]. (%d)\n", i, ret); goto error; @@ -1028,6 +872,106 @@ static const struct file_operations kprobe_profile_ops = { .release = seq_release, }; +/* Kprobe specific fetch functions */ + +/* Return the length of string -- including null terminal byte */ +static nokprobe_inline int +fetch_store_strlen(unsigned long addr) +{ + mm_segment_t old_fs; + int ret, len = 0; + u8 c; + + old_fs = get_fs(); + set_fs(KERNEL_DS); + pagefault_disable(); + + do { + ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1); + len++; + } while (c && ret == 0 && len < MAX_STRING_SIZE); + + pagefault_enable(); + set_fs(old_fs); + + return (ret < 0) ? ret : len; +} + +/* + * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max + * length and relative data location. + */ +static nokprobe_inline int +fetch_store_string(unsigned long addr, void *dest, void *base) +{ + int maxlen = get_loc_len(*(u32 *)dest); + u8 *dst = get_loc_data(dest, base); + long ret; + + if (unlikely(!maxlen)) + return -ENOMEM; + /* + * Try to get string again, since the string can be changed while + * probing. + */ + ret = strncpy_from_unsafe(dst, (void *)addr, maxlen); + + if (ret >= 0) + *(u32 *)dest = make_data_loc(ret, (void *)dst - base); + return ret; +} + +static nokprobe_inline int +probe_mem_read(void *dest, void *src, size_t size) +{ + return probe_kernel_read(dest, src, size); +} + +/* Note that we don't verify it, since the code does not come from user space */ +static int +process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, + void *base) +{ + unsigned long val; + +retry: + /* 1st stage: get value from context */ + switch (code->op) { + case FETCH_OP_REG: + val = regs_get_register(regs, code->param); + break; + case FETCH_OP_STACK: + val = regs_get_kernel_stack_nth(regs, code->param); + break; + case FETCH_OP_STACKP: + val = kernel_stack_pointer(regs); + break; + case FETCH_OP_RETVAL: + val = regs_return_value(regs); + break; + case FETCH_OP_IMM: + val = code->immediate; + break; + case FETCH_OP_COMM: + val = (unsigned long)current->comm; + break; +#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API + case FETCH_OP_ARG: + val = regs_get_kernel_argument(regs, code->param); + break; +#endif + case FETCH_NOP_SYMBOL: /* Ignore a place holder */ + code++; + goto retry; + default: + return -EILSEQ; + } + code++; + + return process_fetch_insn_bottom(code, val, dest, base); +} +NOKPROBE_SYMBOL(process_fetch_insn) + /* Kprobe handler */ static nokprobe_inline void __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs, @@ -1059,7 +1003,7 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs, entry = ring_buffer_event_data(event); entry->ip = (unsigned long)tk->rp.kp.addr; - store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); + store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); event_trigger_unlock_commit_regs(trace_file, buffer, event, entry, irq_flags, pc, regs); @@ -1108,7 +1052,7 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, entry = ring_buffer_event_data(event); entry->func = (unsigned long)tk->rp.kp.addr; entry->ret_ip = (unsigned long)ri->ret_addr; - store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); + store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); event_trigger_unlock_commit_regs(trace_file, buffer, event, entry, irq_flags, pc, regs); @@ -1133,8 +1077,6 @@ print_kprobe_event(struct trace_iterator *iter, int flags, struct kprobe_trace_entry_head *field; struct trace_seq *s = &iter->seq; struct trace_probe *tp; - u8 *data; - int i; field = (struct kprobe_trace_entry_head *)iter->ent; tp = container_of(event, struct trace_probe, call.event); @@ -1146,11 +1088,9 @@ print_kprobe_event(struct trace_iterator *iter, int flags, trace_seq_putc(s, ')'); - data = (u8 *)&field[1]; - for (i = 0; i < tp->nr_args; i++) - if (!tp->args[i].type->print(s, tp->args[i].name, - data + tp->args[i].offset, field)) - goto out; + if (print_probe_args(s, tp->args, tp->nr_args, + (u8 *)&field[1], field) < 0) + goto out; trace_seq_putc(s, '\n'); out: @@ -1164,8 +1104,6 @@ print_kretprobe_event(struct trace_iterator *iter, int flags, struct kretprobe_trace_entry_head *field; struct trace_seq *s = &iter->seq; struct trace_probe *tp; - u8 *data; - int i; field = (struct kretprobe_trace_entry_head *)iter->ent; tp = container_of(event, struct trace_probe, call.event); @@ -1182,11 +1120,9 @@ print_kretprobe_event(struct trace_iterator *iter, int flags, trace_seq_putc(s, ')'); - data = (u8 *)&field[1]; - for (i = 0; i < tp->nr_args; i |