// SPDX-License-Identifier: GPL-2.0/* * uprobes-based tracing events * * Copyright (C) IBM Corporation, 2010-2012 * Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com> */#define pr_fmt(fmt) "trace_uprobe: " fmt #include <linux/bpf-cgroup.h>#include <linux/security.h>#include <linux/ctype.h>#include <linux/module.h>#include <linux/uaccess.h>#include <linux/uprobes.h>#include <linux/namei.h>#include <linux/string.h>#include <linux/rculist.h>#include <linux/filter.h>#include <linux/percpu.h> #include "trace_dynevent.h"#include "trace_probe.h"#include "trace_probe_tmpl.h" #define UPROBE_EVENT_SYSTEM "uprobes" struct uprobe_trace_entry_head { struct trace_entry ent; unsigned long vaddr[];}; #define SIZEOF_TRACE_ENTRY(is_return) \ (sizeof(struct uprobe_trace_entry_head) + \ sizeof(unsigned long) * (is_return ? 2 : 1)) #define DATAOF_TRACE_ENTRY(entry, is_return) \ ((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return)) static int trace_uprobe_create(const char *raw_command);static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev);static int trace_uprobe_release(struct dyn_event *ev);static bool trace_uprobe_is_busy(struct dyn_event *ev);static bool trace_uprobe_match(const char *system, const char *event, int argc, const char **argv, struct dyn_event *ev); static struct dyn_event_operations trace_uprobe_ops = { .create = trace_uprobe_create, .show = trace_uprobe_show, .is_busy = trace_uprobe_is_busy, .free = trace_uprobe_release, .match = trace_uprobe_match,}; /* * uprobe event core functions */struct trace_uprobe { struct dyn_event devent; struct uprobe_consumer consumer; struct path path; char *filename; struct uprobe *uprobe; unsigned long offset; unsigned long ref_ctr_offset; unsigned long __percpu *nhits; struct trace_probe tp;}; static bool is_trace_uprobe(struct dyn_event *ev){ return ev->ops == &trace_uprobe_ops;} static struct trace_uprobe *to_trace_uprobe(struct dyn_event *ev){ return container_of(ev, struct trace_uprobe, devent);} /** * for_each_trace_uprobe - iterate over the trace_uprobe list * @pos: the struct trace_uprobe * for each entry * @dpos: the struct dyn_event * to use as a loop cursor */#define for_each_trace_uprobe(pos, dpos) \ for_each_dyn_event(dpos) \ if (is_trace_uprobe(dpos) && (pos = to_trace_uprobe(dpos))) static int register_uprobe_event(struct trace_uprobe *tu);static int unregister_uprobe_event(struct trace_uprobe *tu); static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs, __u64 *data);static int uretprobe_dispatcher(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs, __u64 *data); #ifdef CONFIG_STACK_GROWSUPstatic unsigned long adjust_stack_addr(unsigned long addr, unsigned int n){ return addr - (n * sizeof(long));}#elsestatic unsigned long adjust_stack_addr(unsigned long addr, unsigned int n){ return addr + (n * sizeof(long));}#endif static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n){ unsigned long ret; unsigned long addr = user_stack_pointer(regs); addr = adjust_stack_addr(addr, n); if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret))) return 0; return ret;} /* * Uprobes-specific fetch functions */static nokprobe_inline intprobe_mem_read(void *dest, void *src, size_t size){ void __user *vaddr = (void __force __user *)src; return copy_from_user(dest, vaddr, size) ? -EFAULT : 0;} static nokprobe_inline intprobe_mem_read_user(void *dest, void *src, size_t size){ return probe_mem_read(dest, src, size);} /* * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max * length and relative data location. */static nokprobe_inline intfetch_store_string(unsigned long addr, void *dest, void *base){ long ret; u32 loc = *(u32 *)dest; int maxlen = get_loc_len(loc); u8 *dst = get_loc_data(dest, base); void __user *src = (void __force __user *) addr; if (unlikely(!maxlen)) return -ENOMEM; if (addr == FETCH_TOKEN_COMM) ret = strscpy(dst, current->comm, maxlen); else ret = strncpy_from_user(dst, src, maxlen); if (ret >= 0) { if (ret == maxlen) dst[ret - 1] = '\0'; else /* * Include the terminating null byte. In this case it * was copied by strncpy_from_user but not accounted * for in ret. */ ret++; *(u32 *)dest = make_data_loc(ret, (void *)dst - base); } else *(u32 *)dest = make_data_loc(0, (void *)dst - base); return ret;} static nokprobe_inline intfetch_store_string_user(unsigned long addr, void *dest, void *base){ return fetch_store_string(addr, dest, base);} /* Return the length of string -- including null terminal byte */static nokprobe_inline intfetch_store_strlen(unsigned long addr){ int len; void __user *vaddr = (void __force __user *) addr; if (addr == FETCH_TOKEN_COMM) len = strlen(current->comm) + 1; else len = strnlen_user(vaddr, MAX_STRING_SIZE); return (len > MAX_STRING_SIZE) ? 0 : len;} static nokprobe_inline intfetch_store_strlen_user(unsigned long addr){ return fetch_store_strlen(addr);} static unsigned long translate_user_vaddr(unsigned long file_offset){ unsigned long base_addr; struct uprobe_dispatch_data *udd; udd = (void *) current->utask->vaddr; base_addr = udd->bp_addr - udd->tu->offset; return base_addr + file_offset;} /* Note that we don't verify it, since the code does not come from user space */static intprocess_fetch_insn(struct fetch_insn *code, void *rec, void *edata, void *dest, void *base){ struct pt_regs *regs = rec; unsigned long val; int ret; /* 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 = get_user_stack_nth(regs, code->param); break; case FETCH_OP_STACKP: val = user_stack_pointer(regs); break; case FETCH_OP_RETVAL: val = regs_return_value(regs); break; case FETCH_OP_COMM: val = FETCH_TOKEN_COMM; break; case FETCH_OP_FOFFS: val = translate_user_vaddr(code->immediate); break; default: ret = process_common_fetch_insn(code, &val); if (ret < 0) return ret; } code++; return process_fetch_insn_bottom(code, val, dest, base);}NOKPROBE_SYMBOL(process_fetch_insn) static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter){ rwlock_init(&filter->rwlock); filter->nr_systemwide = 0; INIT_LIST_HEAD(&filter->perf_events);} static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter){ return !filter->nr_systemwide && list_empty(&filter->perf_events);} static inline bool is_ret_probe(struct trace_uprobe *tu){ return tu->consumer.ret_handler != NULL;} static bool trace_uprobe_is_busy(struct dyn_event *ev){ struct trace_uprobe *tu = to_trace_uprobe(ev); return trace_probe_is_enabled(&tu->tp);} static bool trace_uprobe_match_command_head(struct trace_uprobe *tu, int argc, const char **argv){ char buf[MAX_ARGSTR_LEN + 1]; int len; if (!argc) return true; len = strlen(tu->filename); if (strncmp(tu->filename, argv[0], len) || argv[0][len] != ':') return false; if (tu->ref_ctr_offset == 0) snprintf(buf, sizeof(buf), "0x%0*lx", (int)(sizeof(void *) * 2), tu->offset); else snprintf(buf, sizeof(buf), "0x%0*lx(0x%lx)", (int)(sizeof(void *) * 2), tu->offset, tu->ref_ctr_offset); if (strcmp(buf, &argv[0][len + 1])) return false; argc--; argv++; return trace_probe_match_command_args(&tu->tp, argc, argv);} static bool trace_uprobe_match(const char *system, const char *event, int argc, const char **argv, struct dyn_event *ev){ struct trace_uprobe *tu = to_trace_uprobe(ev); return (event[0] == '\0' || strcmp(trace_probe_name(&tu->tp), event) == 0) && (!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0) && trace_uprobe_match_command_head(tu, argc, argv);} static nokprobe_inline struct trace_uprobe *trace_uprobe_primary_from_call(struct trace_event_call *call){ struct trace_probe *tp; tp = trace_probe_primary_from_call(call); if (WARN_ON_ONCE(!tp)) return NULL; return container_of(tp, struct trace_uprobe, tp);} /* * Allocate new trace_uprobe and initialize it (including uprobes). */static struct trace_uprobe *alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret){ struct trace_uprobe *tu; int ret; tu = kzalloc(struct_size(tu, tp.args, nargs), GFP_KERNEL); if (!tu) return ERR_PTR(-ENOMEM); tu->nhits = alloc_percpu(unsigned long); if (!tu->nhits) { ret = -ENOMEM; goto error; } ret = trace_probe_init(&tu->tp, event, group, true, nargs); if (ret < 0) goto error; dyn_event_init(&tu->devent, &trace_uprobe_ops); tu->consumer.handler = uprobe_dispatcher; if (is_ret) tu->consumer.ret_handler = uretprobe_dispatcher; init_trace_uprobe_filter(tu->tp.event->filter); return tu; error: free_percpu(tu->nhits); kfree(tu); return ERR_PTR(ret);} static void free_trace_uprobe(struct trace_uprobe *tu){ if (!tu) return; path_put(&tu->path); trace_probe_cleanup(&tu->tp); kfree(tu->filename); free_percpu(tu->nhits); kfree(tu);} static struct trace_uprobe *find_probe_event(const char *event, const char *group){ struct dyn_event *pos; struct trace_uprobe *tu; for_each_trace_uprobe(tu, pos) if (strcmp(trace_probe_name(&tu->tp), event) == 0 && strcmp(trace_probe_group_name(&tu->tp), group) == 0) return tu; return NULL;} /* Unregister a trace_uprobe and probe_event */static int unregister_trace_uprobe(struct trace_uprobe *tu){ int ret; if (trace_probe_has_sibling(&tu->tp)) goto unreg; /* If there's a reference to the dynamic event */ if (trace_event_dyn_busy(trace_probe_event_call(&tu->tp))) return -EBUSY; ret = unregister_uprobe_event(tu); if (ret) return ret; unreg: dyn_event_remove(&tu->devent); trace_probe_unlink(&tu->tp); free_trace_uprobe(tu); return 0;} static bool trace_uprobe_has_same_uprobe(struct trace_uprobe *orig, struct trace_uprobe *comp){ struct trace_probe_event *tpe = orig->tp.event; struct inode *comp_inode = d_real_inode(comp->path.dentry); int i; list_for_each_entry(orig, &tpe->probes, tp.list) { if (comp_inode != d_real_inode(orig->path.dentry) || comp->offset != orig->offset) continue; /* * trace_probe_compare_arg_type() ensured that nr_args and * each argument name and type are same. Let's compare comm. */ for (i = 0; i < orig->tp.nr_args; i++) { if (strcmp(orig->tp.args[i].comm, comp->tp.args[i].comm)) break; } if (i == orig->tp.nr_args) return true; } return false;} static int append_trace_uprobe(struct trace_uprobe *tu, struct trace_uprobe *to){ int ret; ret = trace_probe_compare_arg_type(&tu->tp, &to->tp); if (ret) { /* Note that argument starts index = 2 */ trace_probe_log_set_index(ret + 1); trace_probe_log_err(0, DIFF_ARG_TYPE); return -EEXIST; } if (trace_uprobe_has_same_uprobe(to, tu)) { trace_probe_log_set_index(0); trace_probe_log_err(0, SAME_PROBE); return -EEXIST; } /* Append to existing event */ ret = trace_probe_append(&tu->tp, &to->tp); if (!ret) dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp)); return ret;} /* * Uprobe with multiple reference counter is not allowed. i.e. * If inode and offset matches, reference counter offset *must* * match as well. Though, there is one exception: If user is * replacing old trace_uprobe with new one(same group/event), * then we allow same uprobe with new reference counter as far * as the new one does not conflict with any other existing * ones. */static int validate_ref_ctr_offset(struct trace_uprobe *new){ struct dyn_event *pos; struct trace_uprobe *tmp; struct inode *new_inode = d_real_inode(new->path.dentry); for_each_trace_uprobe(tmp, pos) { if (new_inode == d_real_inode(tmp->path.dentry) && new->offset == tmp->offset && new->ref_ctr_offset != tmp->ref_ctr_offset) { pr_warn("Reference counter offset mismatch."); return -EINVAL; } } return 0;} /* Register a trace_uprobe and probe_event */static int register_trace_uprobe(struct trace_uprobe *tu){ struct trace_uprobe *old_tu; int ret; Lines 1–500 of 1711. Load more
// SPDX-License-Identifier: GPL-2.0 /* * uprobes-based tracing events * * Copyright (C) IBM Corporation, 2010-2012 * Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com> */ #define pr_fmt(fmt) "trace_uprobe: " fmt #include <linux/bpf-cgroup.h> #include <linux/security.h> #include <linux/ctype.h> #include <linux/module.h> #include <linux/uaccess.h> #include <linux/uprobes.h> #include <linux/namei.h> #include <linux/string.h> #include <linux/rculist.h> #include <linux/filter.h> #include <linux/percpu.h> #include "trace_dynevent.h" #include "trace_probe.h" #include "trace_probe_tmpl.h" #define UPROBE_EVENT_SYSTEM "uprobes" struct uprobe_trace_entry_head { struct trace_entry ent; unsigned long vaddr[]; }; #define SIZEOF_TRACE_ENTRY(is_return) \ (sizeof(struct uprobe_trace_entry_head) + \ sizeof(unsigned long) * (is_return ? 2 : 1)) #define DATAOF_TRACE_ENTRY(entry, is_return) \ ((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return)) static int trace_uprobe_create(const char *raw_command); static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev); static int trace_uprobe_release(struct dyn_event *ev); static bool trace_uprobe_is_busy(struct dyn_event *ev); static bool trace_uprobe_match(const char *system, const char *event, int argc, const char **argv, struct dyn_event *ev); static struct dyn_event_operations trace_uprobe_ops = { .create = trace_uprobe_create, .show = trace_uprobe_show, .is_busy = trace_uprobe_is_busy, .free = trace_uprobe_release, .match = trace_uprobe_match, }; /* * uprobe event core functions */ struct trace_uprobe { struct dyn_event devent; struct uprobe_consumer consumer; struct path path; char *filename; struct uprobe *uprobe; unsigned long offset; unsigned long ref_ctr_offset; unsigned long __percpu *nhits; struct trace_probe tp; }; static bool is_trace_uprobe(struct dyn_event *ev) { return ev->ops == &trace_uprobe_ops; } static struct trace_uprobe *to_trace_uprobe(struct dyn_event *ev) { return container_of(ev, struct trace_uprobe, devent); } /** * for_each_trace_uprobe - iterate over the trace_uprobe list * @pos: the struct trace_uprobe * for each entry * @dpos: the struct dyn_event * to use as a loop cursor */ #define for_each_trace_uprobe(pos, dpos) \ for_each_dyn_event(dpos) \ if (is_trace_uprobe(dpos) && (pos = to_trace_uprobe(dpos))) static int register_uprobe_event(struct trace_uprobe *tu); static int unregister_uprobe_event(struct trace_uprobe *tu); static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs, __u64 *data); static int uretprobe_dispatcher(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs, __u64 *data); #ifdef CONFIG_STACK_GROWSUP static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n) { return addr - (n * sizeof(long)); } #else static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n) { return addr + (n * sizeof(long)); } #endif static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n) { unsigned long ret; unsigned long addr = user_stack_pointer(regs); addr = adjust_stack_addr(addr, n); if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret))) return 0; return ret; } /* * Uprobes-specific fetch functions */ static nokprobe_inline int probe_mem_read(void *dest, void *src, size_t size) { void __user *vaddr = (void __force __user *)src; return copy_from_user(dest, vaddr, size) ? -EFAULT : 0; } static nokprobe_inline int probe_mem_read_user(void *dest, void *src, size_t size) { return probe_mem_read(dest, src, size); } /* * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max * length and relative data location. */ static nokprobe_inline int fetch_store_string(unsigned long addr, void *dest, void *base) { long ret; u32 loc = *(u32 *)dest; int maxlen = get_loc_len(loc); u8 *dst = get_loc_data(dest, base); void __user *src = (void __force __user *) addr; if (unlikely(!maxlen)) return -ENOMEM; if (addr == FETCH_TOKEN_COMM) ret = strscpy(dst, current->comm, maxlen); else ret = strncpy_from_user(dst, src, maxlen); if (ret >= 0) { if (ret == maxlen) dst[ret - 1] = '\0'; else /* * Include the terminating null byte. In this case it * was copied by strncpy_from_user but not accounted * for in ret. */ ret++; *(u32 *)dest = make_data_loc(ret, (void *)dst - base); } else *(u32 *)dest = make_data_loc(0, (void *)dst - base); return ret; } static nokprobe_inline int fetch_store_string_user(unsigned long addr, void *dest, void *base) { return fetch_store_string(addr, dest, base); } /* Return the length of string -- including null terminal byte */ static nokprobe_inline int fetch_store_strlen(unsigned long addr) { int len; void __user *vaddr = (void __force __user *) addr; if (addr == FETCH_TOKEN_COMM) len = strlen(current->comm) + 1; else len = strnlen_user(vaddr, MAX_STRING_SIZE); return (len > MAX_STRING_SIZE) ? 0 : len; } static nokprobe_inline int fetch_store_strlen_user(unsigned long addr) { return fetch_store_strlen(addr); } static unsigned long translate_user_vaddr(unsigned long file_offset) { unsigned long base_addr; struct uprobe_dispatch_data *udd; udd = (void *) current->utask->vaddr; base_addr = udd->bp_addr - udd->tu->offset; return base_addr + file_offset; } /* 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, void *rec, void *edata, void *dest, void *base) { struct pt_regs *regs = rec; unsigned long val; int ret; /* 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 = get_user_stack_nth(regs, code->param); break; case FETCH_OP_STACKP: val = user_stack_pointer(regs); break; case FETCH_OP_RETVAL: val = regs_return_value(regs); break; case FETCH_OP_COMM: val = FETCH_TOKEN_COMM; break; case FETCH_OP_FOFFS: val = translate_user_vaddr(code->immediate); break; default: ret = process_common_fetch_insn(code, &val); if (ret < 0) return ret; } code++; return process_fetch_insn_bottom(code, val, dest, base); } NOKPROBE_SYMBOL(process_fetch_insn) static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter) { rwlock_init(&filter->rwlock); filter->nr_systemwide = 0; INIT_LIST_HEAD(&filter->perf_events); } static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter) { return !filter->nr_systemwide && list_empty(&filter->perf_events); } static inline bool is_ret_probe(struct trace_uprobe *tu) { return tu->consumer.ret_handler != NULL; } static bool trace_uprobe_is_busy(struct dyn_event *ev) { struct trace_uprobe *tu = to_trace_uprobe(ev); return trace_probe_is_enabled(&tu->tp); } static bool trace_uprobe_match_command_head(struct trace_uprobe *tu, int argc, const char **argv) { char buf[MAX_ARGSTR_LEN + 1]; int len; if (!argc) return true; len = strlen(tu->filename); if (strncmp(tu->filename, argv[0], len) || argv[0][len] != ':') return false; if (tu->ref_ctr_offset == 0) snprintf(buf, sizeof(buf), "0x%0*lx", (int)(sizeof(void *) * 2), tu->offset); else snprintf(buf, sizeof(buf), "0x%0*lx(0x%lx)", (int)(sizeof(void *) * 2), tu->offset, tu->ref_ctr_offset); if (strcmp(buf, &argv[0][len + 1])) return false; argc--; argv++; return trace_probe_match_command_args(&tu->tp, argc, argv); } static bool trace_uprobe_match(const char *system, const char *event, int argc, const char **argv, struct dyn_event *ev) { struct trace_uprobe *tu = to_trace_uprobe(ev); return (event[0] == '\0' || strcmp(trace_probe_name(&tu->tp), event) == 0) && (!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0) && trace_uprobe_match_command_head(tu, argc, argv); } static nokprobe_inline struct trace_uprobe * trace_uprobe_primary_from_call(struct trace_event_call *call) { struct trace_probe *tp; tp = trace_probe_primary_from_call(call); if (WARN_ON_ONCE(!tp)) return NULL; return container_of(tp, struct trace_uprobe, tp); } /* * Allocate new trace_uprobe and initialize it (including uprobes). */ static struct trace_uprobe * alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret) { struct trace_uprobe *tu; int ret; tu = kzalloc(struct_size(tu, tp.args, nargs), GFP_KERNEL); if (!tu) return ERR_PTR(-ENOMEM); tu->nhits = alloc_percpu(unsigned long); if (!tu->nhits) { ret = -ENOMEM; goto error; } ret = trace_probe_init(&tu->tp, event, group, true, nargs); if (ret < 0) goto error; dyn_event_init(&tu->devent, &trace_uprobe_ops); tu->consumer.handler = uprobe_dispatcher; if (is_ret) tu->consumer.ret_handler = uretprobe_dispatcher; init_trace_uprobe_filter(tu->tp.event->filter); return tu; error: free_percpu(tu->nhits); kfree(tu); return ERR_PTR(ret); } static void free_trace_uprobe(struct trace_uprobe *tu) { if (!tu) return; path_put(&tu->path); trace_probe_cleanup(&tu->tp); kfree(tu->filename); free_percpu(tu->nhits); kfree(tu); } static struct trace_uprobe *find_probe_event(const char *event, const char *group) { struct dyn_event *pos; struct trace_uprobe *tu; for_each_trace_uprobe(tu, pos) if (strcmp(trace_probe_name(&tu->tp), event) == 0 && strcmp(trace_probe_group_name(&tu->tp), group) == 0) return tu; return NULL; } /* Unregister a trace_uprobe and probe_event */ static int unregister_trace_uprobe(struct trace_uprobe *tu) { int ret; if (trace_probe_has_sibling(&tu->tp)) goto unreg; /* If there's a reference to the dynamic event */ if (trace_event_dyn_busy(trace_probe_event_call(&tu->tp))) return -EBUSY; ret = unregister_uprobe_event(tu); if (ret) return ret; unreg: dyn_event_remove(&tu->devent); trace_probe_unlink(&tu->tp); free_trace_uprobe(tu); return 0; } static bool trace_uprobe_has_same_uprobe(struct trace_uprobe *orig, struct trace_uprobe *comp) { struct trace_probe_event *tpe = orig->tp.event; struct inode *comp_inode = d_real_inode(comp->path.dentry); int i; list_for_each_entry(orig, &tpe->probes, tp.list) { if (comp_inode != d_real_inode(orig->path.dentry) || comp->offset != orig->offset) continue; /* * trace_probe_compare_arg_type() ensured that nr_args and * each argument name and type are same. Let's compare comm. */ for (i = 0; i < orig->tp.nr_args; i++) { if (strcmp(orig->tp.args[i].comm, comp->tp.args[i].comm)) break; } if (i == orig->tp.nr_args) return true; } return false; } static int append_trace_uprobe(struct trace_uprobe *tu, struct trace_uprobe *to) { int ret; ret = trace_probe_compare_arg_type(&tu->tp, &to->tp); if (ret) { /* Note that argument starts index = 2 */ trace_probe_log_set_index(ret + 1); trace_probe_log_err(0, DIFF_ARG_TYPE); return -EEXIST; } if (trace_uprobe_has_same_uprobe(to, tu)) { trace_probe_log_set_index(0); trace_probe_log_err(0, SAME_PROBE); return -EEXIST; } /* Append to existing event */ ret = trace_probe_append(&tu->tp, &to->tp); if (!ret) dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp)); return ret; } /* * Uprobe with multiple reference counter is not allowed. i.e. * If inode and offset matches, reference counter offset *must* * match as well. Though, there is one exception: If user is * replacing old trace_uprobe with new one(same group/event), * then we allow same uprobe with new reference counter as far * as the new one does not conflict with any other existing * ones. */ static int validate_ref_ctr_offset(struct trace_uprobe *new) { struct dyn_event *pos; struct trace_uprobe *tmp; struct inode *new_inode = d_real_inode(new->path.dentry); for_each_trace_uprobe(tmp, pos) { if (new_inode == d_real_inode(tmp->path.dentry) && new->offset == tmp->offset && new->ref_ctr_offset != tmp->ref_ctr_offset) { pr_warn("Reference counter offset mismatch."); return -EINVAL; } } return 0; } /* Register a trace_uprobe and probe_event */ static int register_trace_uprobe(struct trace_uprobe *tu) { struct trace_uprobe *old_tu; int ret;