From: Peter Zijlstra <[email protected]> This patch migrates BPF program symbols from bpf_tree to kallsym_tree. Since kallsym_tree_add/del already calls perf_event_ksymbol(), this patch also removes unnecessary perf_event_bpf_emit_ksymbols().
Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Signed-off-by: Song Liu <[email protected]> --- include/linux/bpf.h | 7 +- include/linux/filter.h | 42 ----------- kernel/bpf/core.c | 167 +++++------------------------------------ kernel/events/core.c | 35 --------- kernel/extable.c | 4 +- kernel/kallsyms.c | 19 +---- 6 files changed, 25 insertions(+), 249 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index e734f163bd0b..403e1f88a1fa 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -13,7 +13,7 @@ #include <linux/file.h> #include <linux/percpu.h> #include <linux/err.h> -#include <linux/rbtree_latch.h> +#include <linux/kallsyms.h> #include <linux/numa.h> #include <linux/wait.h> @@ -307,8 +307,9 @@ struct bpf_prog_aux { bool offload_requested; struct bpf_prog **func; void *jit_data; /* JIT specific data. arch dependent */ - struct latch_tree_node ksym_tnode; - struct list_head ksym_lnode; + + struct kallsym_node ktn; + const struct bpf_prog_ops *ops; struct bpf_map **used_maps; struct bpf_prog *prog; diff --git a/include/linux/filter.h b/include/linux/filter.h index d531d4250bff..61264a3f944c 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -932,23 +932,6 @@ static inline bool bpf_jit_kallsyms_enabled(void) return false; } -const char *__bpf_address_lookup(unsigned long addr, unsigned long *size, - unsigned long *off, char *sym); -bool is_bpf_text_address(unsigned long addr); -int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type, - char *sym); - -static inline const char * -bpf_address_lookup(unsigned long addr, unsigned long *size, - unsigned long *off, char **modname, char *sym) -{ - const char *ret = __bpf_address_lookup(addr, size, off, sym); - - if (ret && modname) - *modname = NULL; - return ret; -} - void bpf_prog_kallsyms_add(struct bpf_prog *fp); void bpf_prog_kallsyms_del(struct bpf_prog *fp); void bpf_get_prog_name(const struct bpf_prog *prog, char *sym); @@ -975,31 +958,6 @@ static inline bool bpf_jit_kallsyms_enabled(void) return false; } -static inline const char * -__bpf_address_lookup(unsigned long addr, unsigned long *size, - unsigned long *off, char *sym) -{ - return NULL; -} - -static inline bool is_bpf_text_address(unsigned long addr) -{ - return false; -} - -static inline int bpf_get_kallsym(unsigned int symnum, unsigned long *value, - char *type, char *sym) -{ - return -ERANGE; -} - -static inline const char * -bpf_address_lookup(unsigned long addr, unsigned long *size, - unsigned long *off, char **modname, char *sym) -{ - return NULL; -} - static inline void bpf_prog_kallsyms_add(struct bpf_prog *fp) { } diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 19c49313c709..e53912234a91 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -30,7 +30,6 @@ #include <linux/bpf.h> #include <linux/btf.h> #include <linux/frame.h> -#include <linux/rbtree_latch.h> #include <linux/kallsyms.h> #include <linux/rcupdate.h> #include <linux/perf_event.h> @@ -100,8 +99,6 @@ struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags) fp->aux->prog = fp; fp->jit_requested = ebpf_jit_enabled(); - INIT_LIST_HEAD_RCU(&fp->aux->ksym_lnode); - return fp; } EXPORT_SYMBOL_GPL(bpf_prog_alloc); @@ -530,86 +527,38 @@ void bpf_get_prog_name(const struct bpf_prog *prog, char *sym) *sym = 0; } -static __always_inline unsigned long -bpf_get_prog_addr_start(struct latch_tree_node *n) -{ - unsigned long symbol_start, symbol_end; - const struct bpf_prog_aux *aux; - - aux = container_of(n, struct bpf_prog_aux, ksym_tnode); - bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end); - - return symbol_start; -} - -static __always_inline bool bpf_tree_less(struct latch_tree_node *a, - struct latch_tree_node *b) -{ - return bpf_get_prog_addr_start(a) < bpf_get_prog_addr_start(b); -} - -static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n) -{ - unsigned long val = (unsigned long)key; - unsigned long symbol_start, symbol_end; - const struct bpf_prog_aux *aux; - - aux = container_of(n, struct bpf_prog_aux, ksym_tnode); - bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end); - - if (val < symbol_start) - return -1; - if (val >= symbol_end) - return 1; - - return 0; -} - -static const struct latch_tree_ops bpf_tree_ops = { - .less = bpf_tree_less, - .comp = bpf_tree_comp, -}; - -static DEFINE_SPINLOCK(bpf_lock); -static LIST_HEAD(bpf_kallsyms); -static struct latch_tree_root bpf_tree __cacheline_aligned; - -static void bpf_prog_ksym_node_add(struct bpf_prog_aux *aux) -{ - WARN_ON_ONCE(!list_empty(&aux->ksym_lnode)); - list_add_tail_rcu(&aux->ksym_lnode, &bpf_kallsyms); - latch_tree_insert(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops); -} - -static void bpf_prog_ksym_node_del(struct bpf_prog_aux *aux) -{ - if (list_empty(&aux->ksym_lnode)) - return; - - latch_tree_erase(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops); - list_del_rcu(&aux->ksym_lnode); -} static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp) { return fp->jited && !bpf_prog_was_classic(fp); } -static bool bpf_prog_kallsyms_verify_off(const struct bpf_prog *fp) +static void bpf_kn_names(struct kallsym_node *kn, char *sym, char **modname) { - return list_empty(&fp->aux->ksym_lnode) || - fp->aux->ksym_lnode.prev == LIST_POISON2; + struct bpf_prog_aux *aux = container_of(kn, struct bpf_prog_aux, ktn); + + *modname = "eBPF-jit"; + bpf_get_prog_name(aux->prog, sym); } void bpf_prog_kallsyms_add(struct bpf_prog *fp) { + unsigned long sym_start, sym_end; + if (!bpf_prog_kallsyms_candidate(fp) || !capable(CAP_SYS_ADMIN)) return; - spin_lock_bh(&bpf_lock); - bpf_prog_ksym_node_add(fp->aux); - spin_unlock_bh(&bpf_lock); + bpf_get_prog_addr_region(fp, &sym_start, &sym_end); + + fp->aux->ktn.kn_addr = sym_start; + fp->aux->ktn.kn_len = sym_end - sym_start; + fp->aux->ktn.kn_names = bpf_kn_names; +#ifdef CONFIG_PERF_EVENTS + fp->aux->ktn.ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF; +#endif + + kallsym_tree_add(&fp->aux->ktn); } void bpf_prog_kallsyms_del(struct bpf_prog *fp) @@ -617,85 +566,7 @@ void bpf_prog_kallsyms_del(struct bpf_prog *fp) if (!bpf_prog_kallsyms_candidate(fp)) return; - spin_lock_bh(&bpf_lock); - bpf_prog_ksym_node_del(fp->aux); - spin_unlock_bh(&bpf_lock); -} - -static struct bpf_prog *bpf_prog_kallsyms_find(unsigned long addr) -{ - struct latch_tree_node *n; - - if (!bpf_jit_kallsyms_enabled()) - return NULL; - - n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops); - return n ? - container_of(n, struct bpf_prog_aux, ksym_tnode)->prog : - NULL; -} - -const char *__bpf_address_lookup(unsigned long addr, unsigned long *size, - unsigned long *off, char *sym) -{ - unsigned long symbol_start, symbol_end; - struct bpf_prog *prog; - char *ret = NULL; - - rcu_read_lock(); - prog = bpf_prog_kallsyms_find(addr); - if (prog) { - bpf_get_prog_addr_region(prog, &symbol_start, &symbol_end); - bpf_get_prog_name(prog, sym); - - ret = sym; - if (size) - *size = symbol_end - symbol_start; - if (off) - *off = addr - symbol_start; - } - rcu_read_unlock(); - - return ret; -} - -bool is_bpf_text_address(unsigned long addr) -{ - bool ret; - - rcu_read_lock(); - ret = bpf_prog_kallsyms_find(addr) != NULL; - rcu_read_unlock(); - - return ret; -} - -int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type, - char *sym) -{ - struct bpf_prog_aux *aux; - unsigned int it = 0; - int ret = -ERANGE; - - if (!bpf_jit_kallsyms_enabled()) - return ret; - - rcu_read_lock(); - list_for_each_entry_rcu(aux, &bpf_kallsyms, ksym_lnode) { - if (it++ != symnum) - continue; - - bpf_get_prog_name(aux->prog, sym); - - *value = (unsigned long)aux->prog->bpf_func; - *type = BPF_SYM_ELF_TYPE; - - ret = 0; - break; - } - rcu_read_unlock(); - - return ret; + kallsym_tree_del(&fp->aux->ktn); } static atomic_long_t bpf_jit_current; @@ -806,8 +677,6 @@ void __weak bpf_jit_free(struct bpf_prog *fp) bpf_jit_binary_unlock_ro(hdr); bpf_jit_binary_free(hdr); - - WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp)); } bpf_prog_unlock_free(fp); diff --git a/kernel/events/core.c b/kernel/events/core.c index 0a8dab322111..5f6ab55f77cf 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7790,31 +7790,6 @@ static void perf_event_bpf_output(struct perf_event *event, void *data) perf_output_end(&handle); } -static void perf_event_bpf_emit_ksymbols(struct bpf_prog *prog, - enum perf_bpf_event_type type) -{ - bool unregister = type == PERF_BPF_EVENT_PROG_UNLOAD; - char sym[KSYM_NAME_LEN]; - int i; - - if (prog->aux->func_cnt == 0) { - bpf_get_prog_name(prog, sym); - perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_BPF, - (u64)(unsigned long)prog->bpf_func, - prog->jited_len, unregister, sym); - } else { - for (i = 0; i < prog->aux->func_cnt; i++) { - struct bpf_prog *subprog = prog->aux->func[i]; - - bpf_get_prog_name(subprog, sym); - perf_event_ksymbol( - PERF_RECORD_KSYMBOL_TYPE_BPF, - (u64)(unsigned long)subprog->bpf_func, - subprog->jited_len, unregister, sym); - } - } -} - void perf_event_bpf_event(struct bpf_prog *prog, enum perf_bpf_event_type type, u16 flags) @@ -7825,16 +7800,6 @@ void perf_event_bpf_event(struct bpf_prog *prog, type >= PERF_BPF_EVENT_MAX) return; - switch (type) { - case PERF_BPF_EVENT_PROG_LOAD: - case PERF_BPF_EVENT_PROG_UNLOAD: - if (atomic_read(&nr_ksymbol_events)) - perf_event_bpf_emit_ksymbols(prog, type); - break; - default: - break; - } - if (!atomic_read(&nr_bpf_events)) return; diff --git a/kernel/extable.c b/kernel/extable.c index 5271e9b649b1..c7b7bd8e24f6 100644 --- a/kernel/extable.c +++ b/kernel/extable.c @@ -135,7 +135,7 @@ int kernel_text_address(unsigned long addr) * coming back from idle, or cpu on or offlining. * * is_module_text_address() as well as the kprobe slots - * and is_bpf_text_address() require RCU to be watching. + * and is_kallsym_tree_text_address() require RCU to be watching. */ no_rcu = !rcu_is_watching(); @@ -151,8 +151,6 @@ int kernel_text_address(unsigned long addr) goto out; if (is_kprobe_optinsn_slot(addr) || is_kprobe_insn_slot(addr)) goto out; - if (is_bpf_text_address(addr)) - goto out; ret = 0; out: if (no_rcu) diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index 30611a5379fd..17bcc6815cf3 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -426,8 +426,7 @@ int kallsyms_lookup_size_offset(unsigned long addr, unsigned long *symbolsize, if (is_ksym_addr(addr)) return !!get_symbol_pos(addr, symbolsize, offset); return !!module_address_lookup(addr, symbolsize, offset, NULL, namebuf) || - !!kallsym_tree_address_lookup(addr, symbolsize, offset, NULL, namebuf) || - !!__bpf_address_lookup(addr, symbolsize, offset, namebuf); + !!kallsym_tree_address_lookup(addr, symbolsize, offset, NULL, namebuf); } /* @@ -465,11 +464,6 @@ const char *kallsyms_lookup(unsigned long addr, if (!ret) ret = kallsym_tree_address_lookup(addr, symbolsize, offset, modname, namebuf); - - if (!ret) - ret = bpf_address_lookup(addr, symbolsize, - offset, modname, namebuf); - if (!ret) ret = ftrace_mod_address_lookup(addr, symbolsize, offset, modname, namebuf); @@ -674,15 +668,6 @@ static int get_ksymbol_ftrace_mod(struct kallsym_iter *iter) return 1; } -static int get_ksymbol_bpf(struct kallsym_iter *iter) -{ - strlcpy(iter->module_name, "bpf", MODULE_NAME_LEN); - iter->exported = 0; - return bpf_get_kallsym(iter->pos - iter->pos_ftrace_mod_end, - &iter->value, &iter->type, - iter->name) < 0 ? 0 : 1; -} - /* Returns space to next name. */ static unsigned long get_ksymbol_core(struct kallsym_iter *iter) { @@ -735,7 +720,7 @@ static int update_iter_mod(struct kallsym_iter *iter, loff_t pos) get_ksymbol_ftrace_mod(iter)) return 1; - return get_ksymbol_bpf(iter); + return 0; } /* Returns false if pos at or past end of file. */ -- 2.17.1
