From a0019cd7d41a191253859349535d76ee28ab7d96 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 16 Mar 2022 13:24:07 +0100 Subject: [PATCH 01/13] lib/sort: Add priv pointer to swap function Adding support to have priv pointer in swap callback function. Following the initial change on cmp callback functions [1] and adding SWAP_WRAPPER macro to identify sort call of sort_r. Signed-off-by: Jiri Olsa Signed-off-by: Alexei Starovoitov Reviewed-by: Masami Hiramatsu Link: https://lore.kernel.org/bpf/20220316122419.933957-2-jolsa@kernel.org [1] 4333fb96ca10 ("media: lib/sort.c: implement sort() variant taking context argument") --- include/linux/sort.h | 2 +- include/linux/types.h | 1 + lib/sort.c | 40 ++++++++++++++++++++++++++++++---------- 3 files changed, 32 insertions(+), 11 deletions(-) diff --git a/include/linux/sort.h b/include/linux/sort.h index b5898725fe9db..e163287ac6c18 100644 --- a/include/linux/sort.h +++ b/include/linux/sort.h @@ -6,7 +6,7 @@ void sort_r(void *base, size_t num, size_t size, cmp_r_func_t cmp_func, - swap_func_t swap_func, + swap_r_func_t swap_func, const void *priv); void sort(void *base, size_t num, size_t size, diff --git a/include/linux/types.h b/include/linux/types.h index ac825ad90e44a..ea8cf60a8a795 100644 --- a/include/linux/types.h +++ b/include/linux/types.h @@ -226,6 +226,7 @@ struct callback_head { typedef void (*rcu_callback_t)(struct rcu_head *head); typedef void (*call_rcu_func_t)(struct rcu_head *head, rcu_callback_t func); +typedef void (*swap_r_func_t)(void *a, void *b, int size, const void *priv); typedef void (*swap_func_t)(void *a, void *b, int size); typedef int (*cmp_r_func_t)(const void *a, const void *b, const void *priv); diff --git a/lib/sort.c b/lib/sort.c index aa18153864d22..b399bf10d6759 100644 --- a/lib/sort.c +++ b/lib/sort.c @@ -122,16 +122,27 @@ static void swap_bytes(void *a, void *b, size_t n) * a pointer, but small integers make for the smallest compare * instructions. */ -#define SWAP_WORDS_64 (swap_func_t)0 -#define SWAP_WORDS_32 (swap_func_t)1 -#define SWAP_BYTES (swap_func_t)2 +#define SWAP_WORDS_64 (swap_r_func_t)0 +#define SWAP_WORDS_32 (swap_r_func_t)1 +#define SWAP_BYTES (swap_r_func_t)2 +#define SWAP_WRAPPER (swap_r_func_t)3 + +struct wrapper { + cmp_func_t cmp; + swap_func_t swap; +}; /* * The function pointer is last to make tail calls most efficient if the * compiler decides not to inline this function. */ -static void do_swap(void *a, void *b, size_t size, swap_func_t swap_func) +static void do_swap(void *a, void *b, size_t size, swap_r_func_t swap_func, const void *priv) { + if (swap_func == SWAP_WRAPPER) { + ((const struct wrapper *)priv)->swap(a, b, (int)size); + return; + } + if (swap_func == SWAP_WORDS_64) swap_words_64(a, b, size); else if (swap_func == SWAP_WORDS_32) @@ -139,7 +150,7 @@ static void do_swap(void *a, void *b, size_t size, swap_func_t swap_func) else if (swap_func == SWAP_BYTES) swap_bytes(a, b, size); else - swap_func(a, b, (int)size); + swap_func(a, b, (int)size, priv); } #define _CMP_WRAPPER ((cmp_r_func_t)0L) @@ -147,7 +158,7 @@ static void do_swap(void *a, void *b, size_t size, swap_func_t swap_func) static int do_cmp(const void *a, const void *b, cmp_r_func_t cmp, const void *priv) { if (cmp == _CMP_WRAPPER) - return ((cmp_func_t)(priv))(a, b); + return ((const struct wrapper *)priv)->cmp(a, b); return cmp(a, b, priv); } @@ -198,7 +209,7 @@ static size_t parent(size_t i, unsigned int lsbit, size_t size) */ void sort_r(void *base, size_t num, size_t size, cmp_r_func_t cmp_func, - swap_func_t swap_func, + swap_r_func_t swap_func, const void *priv) { /* pre-scale counters for performance */ @@ -208,6 +219,10 @@ void sort_r(void *base, size_t num, size_t size, if (!a) /* num < 2 || size == 0 */ return; + /* called from 'sort' without swap function, let's pick the default */ + if (swap_func == SWAP_WRAPPER && !((struct wrapper *)priv)->swap) + swap_func = NULL; + if (!swap_func) { if (is_aligned(base, size, 8)) swap_func = SWAP_WORDS_64; @@ -230,7 +245,7 @@ void sort_r(void *base, size_t num, size_t size, if (a) /* Building heap: sift down --a */ a -= size; else if (n -= size) /* Sorting: Extract root to --n */ - do_swap(base, base + n, size, swap_func); + do_swap(base, base + n, size, swap_func, priv); else /* Sort complete */ break; @@ -257,7 +272,7 @@ void sort_r(void *base, size_t num, size_t size, c = b; /* Where "a" belongs */ while (b != a) { /* Shift it into place */ b = parent(b, lsbit, size); - do_swap(base + b, base + c, size, swap_func); + do_swap(base + b, base + c, size, swap_func, priv); } } } @@ -267,6 +282,11 @@ void sort(void *base, size_t num, size_t size, cmp_func_t cmp_func, swap_func_t swap_func) { - return sort_r(base, num, size, _CMP_WRAPPER, swap_func, cmp_func); + struct wrapper w = { + .cmp = cmp_func, + .swap = swap_func, + }; + + return sort_r(base, num, size, _CMP_WRAPPER, SWAP_WRAPPER, &w); } EXPORT_SYMBOL(sort); From aecf489f2ce51436402818c96639ed6303b540f8 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 16 Mar 2022 13:24:08 +0100 Subject: [PATCH 02/13] kallsyms: Skip the name search for empty string When kallsyms_lookup_name is called with empty string, it will do futile search for it through all the symbols. Skipping the search for empty string. Signed-off-by: Jiri Olsa Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20220316122419.933957-3-jolsa@kernel.org --- kernel/kallsyms.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index 951c93216fc4d..79f2eb617a62a 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -212,6 +212,10 @@ unsigned long kallsyms_lookup_name(const char *name) unsigned long i; unsigned int off; + /* Skip the search for empty string. */ + if (!*name) + return 0; + for (i = 0, off = 0; i < kallsyms_num_syms; i++) { off = kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf)); From 0dcac272540613d41c05e89679e4ddb978b612f1 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 16 Mar 2022 13:24:09 +0100 Subject: [PATCH 03/13] bpf: Add multi kprobe link Adding new link type BPF_LINK_TYPE_KPROBE_MULTI that attaches kprobe program through fprobe API. The fprobe API allows to attach probe on multiple functions at once very fast, because it works on top of ftrace. On the other hand this limits the probe point to the function entry or return. The kprobe program gets the same pt_regs input ctx as when it's attached through the perf API. Adding new attach type BPF_TRACE_KPROBE_MULTI that allows attachment kprobe to multiple function with new link. User provides array of addresses or symbols with count to attach the kprobe program to. The new link_create uapi interface looks like: struct { __u32 flags; __u32 cnt; __aligned_u64 syms; __aligned_u64 addrs; } kprobe_multi; The flags field allows single BPF_TRACE_KPROBE_MULTI bit to create return multi kprobe. Signed-off-by: Masami Hiramatsu Signed-off-by: Jiri Olsa Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220316122419.933957-4-jolsa@kernel.org --- include/linux/bpf_types.h | 1 + include/linux/trace_events.h | 7 ++ include/uapi/linux/bpf.h | 13 ++ kernel/bpf/syscall.c | 26 +++- kernel/trace/bpf_trace.c | 211 +++++++++++++++++++++++++++++++++ tools/include/uapi/linux/bpf.h | 13 ++ 6 files changed, 266 insertions(+), 5 deletions(-) diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h index 48a91c51c015d..3e24ad0c4b3c1 100644 --- a/include/linux/bpf_types.h +++ b/include/linux/bpf_types.h @@ -140,3 +140,4 @@ BPF_LINK_TYPE(BPF_LINK_TYPE_XDP, xdp) #ifdef CONFIG_PERF_EVENTS BPF_LINK_TYPE(BPF_LINK_TYPE_PERF_EVENT, perf) #endif +BPF_LINK_TYPE(BPF_LINK_TYPE_KPROBE_MULTI, kprobe_multi) diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index dcea51fb60e27..8f0e9e7cb4937 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -15,6 +15,7 @@ struct array_buffer; struct tracer; struct dentry; struct bpf_prog; +union bpf_attr; const char *trace_print_flags_seq(struct trace_seq *p, const char *delim, unsigned long flags, @@ -738,6 +739,7 @@ void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp); int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, u32 *fd_type, const char **buf, u64 *probe_offset, u64 *probe_addr); +int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog); #else static inline unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx) { @@ -779,6 +781,11 @@ static inline int bpf_get_perf_event_info(const struct perf_event *event, { return -EOPNOTSUPP; } +static inline int +bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) +{ + return -EOPNOTSUPP; +} #endif enum { diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 99fab54ae9c07..d77f47af77525 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -997,6 +997,7 @@ enum bpf_attach_type { BPF_SK_REUSEPORT_SELECT, BPF_SK_REUSEPORT_SELECT_OR_MIGRATE, BPF_PERF_EVENT, + BPF_TRACE_KPROBE_MULTI, __MAX_BPF_ATTACH_TYPE }; @@ -1011,6 +1012,7 @@ enum bpf_link_type { BPF_LINK_TYPE_NETNS = 5, BPF_LINK_TYPE_XDP = 6, BPF_LINK_TYPE_PERF_EVENT = 7, + BPF_LINK_TYPE_KPROBE_MULTI = 8, MAX_BPF_LINK_TYPE, }; @@ -1118,6 +1120,11 @@ enum bpf_link_type { */ #define BPF_F_XDP_HAS_FRAGS (1U << 5) +/* link_create.kprobe_multi.flags used in LINK_CREATE command for + * BPF_TRACE_KPROBE_MULTI attach type to create return probe. + */ +#define BPF_F_KPROBE_MULTI_RETURN (1U << 0) + /* When BPF ldimm64's insn[0].src_reg != 0 then this can have * the following extensions: * @@ -1475,6 +1482,12 @@ union bpf_attr { */ __u64 bpf_cookie; } perf_event; + struct { + __u32 flags; + __u32 cnt; + __aligned_u64 syms; + __aligned_u64 addrs; + } kprobe_multi; }; } link_create; diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 9beb585be5a69..b8bb67ee6c57b 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -32,6 +32,7 @@ #include #include #include +#include #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \ (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \ @@ -3022,6 +3023,11 @@ static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *pro fput(perf_file); return err; } +#else +static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) +{ + return -EOPNOTSUPP; +} #endif /* CONFIG_PERF_EVENTS */ #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.prog_fd @@ -4255,7 +4261,7 @@ static int tracing_bpf_link_attach(const union bpf_attr *attr, bpfptr_t uattr, return -EINVAL; } -#define BPF_LINK_CREATE_LAST_FIELD link_create.iter_info_len +#define BPF_LINK_CREATE_LAST_FIELD link_create.kprobe_multi.addrs static int link_create(union bpf_attr *attr, bpfptr_t uattr) { enum bpf_prog_type ptype; @@ -4279,7 +4285,6 @@ static int link_create(union bpf_attr *attr, bpfptr_t uattr) ret = tracing_bpf_link_attach(attr, uattr, prog); goto out; case BPF_PROG_TYPE_PERF_EVENT: - case BPF_PROG_TYPE_KPROBE: case BPF_PROG_TYPE_TRACEPOINT: if (attr->link_create.attach_type != BPF_PERF_EVENT) { ret = -EINVAL; @@ -4287,6 +4292,14 @@ static int link_create(union bpf_attr *attr, bpfptr_t uattr) } ptype = prog->type; break; + case BPF_PROG_TYPE_KPROBE: + if (attr->link_create.attach_type != BPF_PERF_EVENT && + attr->link_create.attach_type != BPF_TRACE_KPROBE_MULTI) { + ret = -EINVAL; + goto out; + } + ptype = prog->type; + break; default: ptype = attach_type_to_prog_type(attr->link_create.attach_type); if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type) { @@ -4318,13 +4331,16 @@ static int link_create(union bpf_attr *attr, bpfptr_t uattr) ret = bpf_xdp_link_attach(attr, prog); break; #endif -#ifdef CONFIG_PERF_EVENTS case BPF_PROG_TYPE_PERF_EVENT: case BPF_PROG_TYPE_TRACEPOINT: - case BPF_PROG_TYPE_KPROBE: ret = bpf_perf_link_attach(attr, prog); break; -#endif + case BPF_PROG_TYPE_KPROBE: + if (attr->link_create.attach_type == BPF_PERF_EVENT) + ret = bpf_perf_link_attach(attr, prog); + else + ret = bpf_kprobe_multi_link_attach(attr, prog); + break; default: ret = -EINVAL; } diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index a2024ba32a20d..fffa2171fae41 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -17,6 +17,7 @@ #include #include #include +#include #include @@ -2181,3 +2182,213 @@ static int __init bpf_event_init(void) fs_initcall(bpf_event_init); #endif /* CONFIG_MODULES */ + +#ifdef CONFIG_FPROBE +struct bpf_kprobe_multi_link { + struct bpf_link link; + struct fprobe fp; + unsigned long *addrs; +}; + +static void bpf_kprobe_multi_link_release(struct bpf_link *link) +{ + struct bpf_kprobe_multi_link *kmulti_link; + + kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); + unregister_fprobe(&kmulti_link->fp); +} + +static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link) +{ + struct bpf_kprobe_multi_link *kmulti_link; + + kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); + kvfree(kmulti_link->addrs); + kfree(kmulti_link); +} + +static const struct bpf_link_ops bpf_kprobe_multi_link_lops = { + .release = bpf_kprobe_multi_link_release, + .dealloc = bpf_kprobe_multi_link_dealloc, +}; + +static int +kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, + struct pt_regs *regs) +{ + int err; + + if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { + err = 0; + goto out; + } + + migrate_disable(); + rcu_read_lock(); + err = bpf_prog_run(link->link.prog, regs); + rcu_read_unlock(); + migrate_enable(); + + out: + __this_cpu_dec(bpf_prog_active); + return err; +} + +static void +kprobe_multi_link_handler(struct fprobe *fp, unsigned long entry_ip, + struct pt_regs *regs) +{ + unsigned long saved_ip = instruction_pointer(regs); + struct bpf_kprobe_multi_link *link; + + /* + * Because fprobe's regs->ip is set to the next instruction of + * dynamic-ftrace instruction, correct entry ip must be set, so + * that the bpf program can access entry address via regs as same + * as kprobes. + * + * Both kprobe and kretprobe see the entry ip of traced function + * as instruction pointer. + */ + instruction_pointer_set(regs, entry_ip); + + link = container_of(fp, struct bpf_kprobe_multi_link, fp); + kprobe_multi_link_prog_run(link, regs); + + instruction_pointer_set(regs, saved_ip); +} + +static int +kprobe_multi_resolve_syms(const void *usyms, u32 cnt, + unsigned long *addrs) +{ + unsigned long addr, size; + const char **syms; + int err = -ENOMEM; + unsigned int i; + char *func; + + size = cnt * sizeof(*syms); + syms = kvzalloc(size, GFP_KERNEL); + if (!syms) + return -ENOMEM; + + func = kmalloc(KSYM_NAME_LEN, GFP_KERNEL); + if (!func) + goto error; + + if (copy_from_user(syms, usyms, size)) { + err = -EFAULT; + goto error; + } + + for (i = 0; i < cnt; i++) { + err = strncpy_from_user(func, syms[i], KSYM_NAME_LEN); + if (err == KSYM_NAME_LEN) + err = -E2BIG; + if (err < 0) + goto error; + err = -EINVAL; + addr = kallsyms_lookup_name(func); + if (!addr) + goto error; + if (!kallsyms_lookup_size_offset(addr, &size, NULL)) + goto error; + addr = ftrace_location_range(addr, addr + size - 1); + if (!addr) + goto error; + addrs[i] = addr; + } + + err = 0; +error: + kvfree(syms); + kfree(func); + return err; +} + +int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) +{ + struct bpf_kprobe_multi_link *link = NULL; + struct bpf_link_primer link_primer; + unsigned long *addrs; + u32 flags, cnt, size; + void __user *uaddrs; + void __user *usyms; + int err; + + /* no support for 32bit archs yet */ + if (sizeof(u64) != sizeof(void *)) + return -EOPNOTSUPP; + + if (prog->expected_attach_type != BPF_TRACE_KPROBE_MULTI) + return -EINVAL; + + flags = attr->link_create.kprobe_multi.flags; + if (flags & ~BPF_F_KPROBE_MULTI_RETURN) + return -EINVAL; + + uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs); + usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms); + if (!!uaddrs == !!usyms) + return -EINVAL; + + cnt = attr->link_create.kprobe_multi.cnt; + if (!cnt) + return -EINVAL; + + size = cnt * sizeof(*addrs); + addrs = kvmalloc(size, GFP_KERNEL); + if (!addrs) + return -ENOMEM; + + if (uaddrs) { + if (copy_from_user(addrs, uaddrs, size)) { + err = -EFAULT; + goto error; + } + } else { + err = kprobe_multi_resolve_syms(usyms, cnt, addrs); + if (err) + goto error; + } + + link = kzalloc(sizeof(*link), GFP_KERNEL); + if (!link) { + err = -ENOMEM; + goto error; + } + + bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI, + &bpf_kprobe_multi_link_lops, prog); + + err = bpf_link_prime(&link->link, &link_primer); + if (err) + goto error; + + if (flags & BPF_F_KPROBE_MULTI_RETURN) + link->fp.exit_handler = kprobe_multi_link_handler; + else + link->fp.entry_handler = kprobe_multi_link_handler; + + link->addrs = addrs; + + err = register_fprobe_ips(&link->fp, addrs, cnt); + if (err) { + bpf_link_cleanup(&link_primer); + return err; + } + + return bpf_link_settle(&link_primer); + +error: + kfree(link); + kvfree(addrs); + return err; +} +#else /* !CONFIG_FPROBE */ +int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) +{ + return -EOPNOTSUPP; +} +#endif diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 99fab54ae9c07..d77f47af77525 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -997,6 +997,7 @@ enum bpf_attach_type { BPF_SK_REUSEPORT_SELECT, BPF_SK_REUSEPORT_SELECT_OR_MIGRATE, BPF_PERF_EVENT, + BPF_TRACE_KPROBE_MULTI, __MAX_BPF_ATTACH_TYPE }; @@ -1011,6 +1012,7 @@ enum bpf_link_type { BPF_LINK_TYPE_NETNS = 5, BPF_LINK_TYPE_XDP = 6, BPF_LINK_TYPE_PERF_EVENT = 7, + BPF_LINK_TYPE_KPROBE_MULTI = 8, MAX_BPF_LINK_TYPE, }; @@ -1118,6 +1120,11 @@ enum bpf_link_type { */ #define BPF_F_XDP_HAS_FRAGS (1U << 5) +/* link_create.kprobe_multi.flags used in LINK_CREATE command for + * BPF_TRACE_KPROBE_MULTI attach type to create return probe. + */ +#define BPF_F_KPROBE_MULTI_RETURN (1U << 0) + /* When BPF ldimm64's insn[0].src_reg != 0 then this can have * the following extensions: * @@ -1475,6 +1482,12 @@ union bpf_attr { */ __u64 bpf_cookie; } perf_event; + struct { + __u32 flags; + __u32 cnt; + __aligned_u64 syms; + __aligned_u64 addrs; + } kprobe_multi; }; } link_create; From 42a5712094e89ef0a125ac0f9d0873f9233368b1 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 16 Mar 2022 13:24:10 +0100 Subject: [PATCH 04/13] bpf: Add bpf_get_func_ip kprobe helper for multi kprobe link Adding support to call bpf_get_func_ip helper from kprobe programs attached by multi kprobe link. Signed-off-by: Jiri Olsa Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220316122419.933957-5-jolsa@kernel.org --- kernel/trace/bpf_trace.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index fffa2171fae41..2507509322288 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1037,6 +1037,18 @@ static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { .arg1_type = ARG_PTR_TO_CTX, }; +BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs) +{ + return instruction_pointer(regs); +} + +static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = { + .func = bpf_get_func_ip_kprobe_multi, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, +}; + BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx) { struct bpf_trace_run_ctx *run_ctx; @@ -1280,7 +1292,9 @@ kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_override_return_proto; #endif case BPF_FUNC_get_func_ip: - return &bpf_get_func_ip_proto_kprobe; + return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ? + &bpf_get_func_ip_proto_kprobe_multi : + &bpf_get_func_ip_proto_kprobe; case BPF_FUNC_get_attach_cookie: return &bpf_get_attach_cookie_proto_trace; default: From 97ee4d20ee67eb462581a7af01442de6586e390b Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 16 Mar 2022 13:24:11 +0100 Subject: [PATCH 05/13] bpf: Add support to inline bpf_get_func_ip helper on x86 Adding support to inline it on x86, because it's single load instruction. Signed-off-by: Jiri Olsa Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20220316122419.933957-6-jolsa@kernel.org --- kernel/bpf/verifier.c | 21 ++++++++++++++++++++- kernel/trace/bpf_trace.c | 1 + 2 files changed, 21 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index cf92f9c01556f..0287176bfe9a5 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -13678,7 +13678,7 @@ static int do_misc_fixups(struct bpf_verifier_env *env) continue; } - /* Implement bpf_get_func_ip inline. */ + /* Implement tracing bpf_get_func_ip inline. */ if (prog_type == BPF_PROG_TYPE_TRACING && insn->imm == BPF_FUNC_get_func_ip) { /* Load IP address from ctx - 16 */ @@ -13693,6 +13693,25 @@ static int do_misc_fixups(struct bpf_verifier_env *env) continue; } +#ifdef CONFIG_X86 + /* Implement kprobe_multi bpf_get_func_ip inline. */ + if (prog_type == BPF_PROG_TYPE_KPROBE && + eatype == BPF_TRACE_KPROBE_MULTI && + insn->imm == BPF_FUNC_get_func_ip) { + /* Load IP address from ctx (struct pt_regs) ip */ + insn_buf[0] = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, + offsetof(struct pt_regs, ip)); + + new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, 1); + if (!new_prog) + return -ENOMEM; + + env->prog = prog = new_prog; + insn = new_prog->insnsi + i + delta; + continue; + } +#endif + patch_call_imm: fn = env->ops->get_func_proto(insn->imm, env->prog); /* all functions that have prototype and verifier allowed diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 2507509322288..0e7f8c9bc756d 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1039,6 +1039,7 @@ static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs) { + /* This helper call is inlined by verifier on x86. */ return instruction_pointer(regs); } From ca74823c6e16dd42b7cf60d9fdde80e2a81a67bb Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 16 Mar 2022 13:24:12 +0100 Subject: [PATCH 06/13] bpf: Add cookie support to programs attached with kprobe multi link Adding support to call bpf_get_attach_cookie helper from kprobe programs attached with kprobe multi link. The cookie is provided by array of u64 values, where each value is paired with provided function address or symbol with the same array index. When cookie array is provided it's sorted together with addresses (check bpf_kprobe_multi_cookie_swap). This way we can find cookie based on the address in bpf_get_attach_cookie helper. Suggested-by: Andrii Nakryiko Signed-off-by: Jiri Olsa Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20220316122419.933957-7-jolsa@kernel.org --- include/uapi/linux/bpf.h | 1 + kernel/bpf/syscall.c | 2 +- kernel/trace/bpf_trace.c | 114 ++++++++++++++++++++++++++++++++- tools/include/uapi/linux/bpf.h | 1 + 4 files changed, 116 insertions(+), 2 deletions(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index d77f47af77525..7604e7d5438f8 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -1487,6 +1487,7 @@ union bpf_attr { __u32 cnt; __aligned_u64 syms; __aligned_u64 addrs; + __aligned_u64 cookies; } kprobe_multi; }; } link_create; diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index b8bb67ee6c57b..cdaa1152436aa 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -4261,7 +4261,7 @@ static int tracing_bpf_link_attach(const union bpf_attr *attr, bpfptr_t uattr, return -EINVAL; } -#define BPF_LINK_CREATE_LAST_FIELD link_create.kprobe_multi.addrs +#define BPF_LINK_CREATE_LAST_FIELD link_create.kprobe_multi.cookies static int link_create(union bpf_attr *attr, bpfptr_t uattr) { enum bpf_prog_type ptype; diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 0e7f8c9bc756d..9a7b6be655e41 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -18,6 +18,8 @@ #include #include #include +#include +#include #include @@ -78,6 +80,7 @@ u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, u64 flags, const struct btf **btf, s32 *btf_id); +static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx, u64 ip); /** * trace_call_bpf - invoke BPF program @@ -1050,6 +1053,18 @@ static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = { .arg1_type = ARG_PTR_TO_CTX, }; +BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs) +{ + return bpf_kprobe_multi_cookie(current->bpf_ctx, instruction_pointer(regs)); +} + +static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = { + .func = bpf_get_attach_cookie_kprobe_multi, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, +}; + BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx) { struct bpf_trace_run_ctx *run_ctx; @@ -1297,7 +1312,9 @@ kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) &bpf_get_func_ip_proto_kprobe_multi : &bpf_get_func_ip_proto_kprobe; case BPF_FUNC_get_attach_cookie: - return &bpf_get_attach_cookie_proto_trace; + return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ? + &bpf_get_attach_cookie_proto_kmulti : + &bpf_get_attach_cookie_proto_trace; default: return bpf_tracing_func_proto(func_id, prog); } @@ -2203,6 +2220,13 @@ struct bpf_kprobe_multi_link { struct bpf_link link; struct fprobe fp; unsigned long *addrs; + /* + * The run_ctx here is used to get struct bpf_kprobe_multi_link in + * get_attach_cookie helper, so it can't be used to store data. + */ + struct bpf_run_ctx run_ctx; + u64 *cookies; + u32 cnt; }; static void bpf_kprobe_multi_link_release(struct bpf_link *link) @@ -2219,6 +2243,7 @@ static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link) kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); kvfree(kmulti_link->addrs); + kvfree(kmulti_link->cookies); kfree(kmulti_link); } @@ -2227,10 +2252,60 @@ static const struct bpf_link_ops bpf_kprobe_multi_link_lops = { .dealloc = bpf_kprobe_multi_link_dealloc, }; +static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv) +{ + const struct bpf_kprobe_multi_link *link = priv; + unsigned long *addr_a = a, *addr_b = b; + u64 *cookie_a, *cookie_b; + unsigned long tmp1; + u64 tmp2; + + cookie_a = link->cookies + (addr_a - link->addrs); + cookie_b = link->cookies + (addr_b - link->addrs); + + /* swap addr_a/addr_b and cookie_a/cookie_b values */ + tmp1 = *addr_a; *addr_a = *addr_b; *addr_b = tmp1; + tmp2 = *cookie_a; *cookie_a = *cookie_b; *cookie_b = tmp2; +} + +static int __bpf_kprobe_multi_cookie_cmp(const void *a, const void *b) +{ + const unsigned long *addr_a = a, *addr_b = b; + + if (*addr_a == *addr_b) + return 0; + return *addr_a < *addr_b ? -1 : 1; +} + +static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv) +{ + return __bpf_kprobe_multi_cookie_cmp(a, b); +} + +static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx, u64 ip) +{ + struct bpf_kprobe_multi_link *link; + unsigned long *addr; + u64 *cookie; + + if (WARN_ON_ONCE(!ctx)) + return 0; + link = container_of(ctx, struct bpf_kprobe_multi_link, run_ctx); + if (!link->cookies) + return 0; + addr = bsearch(&ip, link->addrs, link->cnt, sizeof(ip), + __bpf_kprobe_multi_cookie_cmp); + if (!addr) + return 0; + cookie = link->cookies + (addr - link->addrs); + return *cookie; +} + static int kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, struct pt_regs *regs) { + struct bpf_run_ctx *old_run_ctx; int err; if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { @@ -2240,7 +2315,9 @@ kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, migrate_disable(); rcu_read_lock(); + old_run_ctx = bpf_set_run_ctx(&link->run_ctx); err = bpf_prog_run(link->link.prog, regs); + bpf_reset_run_ctx(old_run_ctx); rcu_read_unlock(); migrate_enable(); @@ -2326,9 +2403,11 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr { struct bpf_kprobe_multi_link *link = NULL; struct bpf_link_primer link_primer; + void __user *ucookies; unsigned long *addrs; u32 flags, cnt, size; void __user *uaddrs; + u64 *cookies = NULL; void __user *usyms; int err; @@ -2368,6 +2447,19 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr goto error; } + ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies); + if (ucookies) { + cookies = kvmalloc(size, GFP_KERNEL); + if (!cookies) { + err = -ENOMEM; + goto error; + } + if (copy_from_user(cookies, ucookies, size)) { + err = -EFAULT; + goto error; + } + } + link = kzalloc(sizeof(*link), GFP_KERNEL); if (!link) { err = -ENOMEM; @@ -2387,6 +2479,21 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr link->fp.entry_handler = kprobe_multi_link_handler; link->addrs = addrs; + link->cookies = cookies; + link->cnt = cnt; + + if (cookies) { + /* + * Sorting addresses will trigger sorting cookies as well + * (check bpf_kprobe_multi_cookie_swap). This way we can + * find cookie based on the address in bpf_get_attach_cookie + * helper. + */ + sort_r(addrs, cnt, sizeof(*addrs), + bpf_kprobe_multi_cookie_cmp, + bpf_kprobe_multi_cookie_swap, + link); + } err = register_fprobe_ips(&link->fp, addrs, cnt); if (err) { @@ -2399,6 +2506,7 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr error: kfree(link); kvfree(addrs); + kvfree(cookies); return err; } #else /* !CONFIG_FPROBE */ @@ -2406,4 +2514,8 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr { return -EOPNOTSUPP; } +static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx, u64 ip) +{ + return 0; +} #endif diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index d77f47af77525..7604e7d5438f8 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -1487,6 +1487,7 @@ union bpf_attr { __u32 cnt; __aligned_u64 syms; __aligned_u64 addrs; + __aligned_u64 cookies; } kprobe_multi; }; } link_create; From 85153ac06283408e6ccaf002b02fd85f0bdab94b Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 16 Mar 2022 13:24:13 +0100 Subject: [PATCH 07/13] libbpf: Add libbpf_kallsyms_parse function Move the kallsyms parsing in internal libbpf_kallsyms_parse function, so it can be used from other places. It will be used in following changes. Signed-off-by: Jiri Olsa Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220316122419.933957-8-jolsa@kernel.org --- tools/lib/bpf/libbpf.c | 62 ++++++++++++++++++++------------- tools/lib/bpf/libbpf_internal.h | 5 +++ 2 files changed, 43 insertions(+), 24 deletions(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 43161fdd44bbf..1ca520a29fdbc 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -7171,12 +7171,10 @@ static int bpf_object__sanitize_maps(struct bpf_object *obj) return 0; } -static int bpf_object__read_kallsyms_file(struct bpf_object *obj) +int libbpf_kallsyms_parse(kallsyms_cb_t cb, void *ctx) { char sym_type, sym_name[500]; unsigned long long sym_addr; - const struct btf_type *t; - struct extern_desc *ext; int ret, err = 0; FILE *f; @@ -7195,35 +7193,51 @@ static int bpf_object__read_kallsyms_file(struct bpf_object *obj) if (ret != 3) { pr_warn("failed to read kallsyms entry: %d\n", ret); err = -EINVAL; - goto out; + break; } - ext = find_extern_by_name(obj, sym_name); - if (!ext || ext->type != EXT_KSYM) - continue; - - t = btf__type_by_id(obj->btf, ext->btf_id); - if (!btf_is_var(t)) - continue; - - if (ext->is_set && ext->ksym.addr != sym_addr) { - pr_warn("extern (ksym) '%s' resolution is ambiguous: 0x%llx or 0x%llx\n", - sym_name, ext->ksym.addr, sym_addr); - err = -EINVAL; - goto out; - } - if (!ext->is_set) { - ext->is_set = true; - ext->ksym.addr = sym_addr; - pr_debug("extern (ksym) %s=0x%llx\n", sym_name, sym_addr); - } + err = cb(sym_addr, sym_type, sym_name, ctx); + if (err) + break; } -out: fclose(f); return err; } +static int kallsyms_cb(unsigned long long sym_addr, char sym_type, + const char *sym_name, void *ctx) +{ + struct bpf_object *obj = ctx; + const struct btf_type *t; + struct extern_desc *ext; + + ext = find_extern_by_name(obj, sym_name); + if (!ext || ext->type != EXT_KSYM) + return 0; + + t = btf__type_by_id(obj->btf, ext->btf_id); + if (!btf_is_var(t)) + return 0; + + if (ext->is_set && ext->ksym.addr != sym_addr) { + pr_warn("extern (ksym) '%s' resolution is ambiguous: 0x%llx or 0x%llx\n", + sym_name, ext->ksym.addr, sym_addr); + return -EINVAL; + } + if (!ext->is_set) { + ext->is_set = true; + ext->ksym.addr = sym_addr; + pr_debug("extern (ksym) %s=0x%llx\n", sym_name, sym_addr); + } + return 0; +} + +static int bpf_object__read_kallsyms_file(struct bpf_object *obj) +{ + return libbpf_kallsyms_parse(kallsyms_cb, obj); +} + static int find_ksym_btf_id(struct bpf_object *obj, const char *ksym_name, __u16 kind, struct btf **res_btf, struct module_btf **res_mod_btf) diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h index 4fda8bdf0a0dc..b6247dc7f8eb0 100644 --- a/tools/lib/bpf/libbpf_internal.h +++ b/tools/lib/bpf/libbpf_internal.h @@ -449,6 +449,11 @@ __s32 btf__find_by_name_kind_own(const struct btf *btf, const char *type_name, extern enum libbpf_strict_mode libbpf_mode; +typedef int (*kallsyms_cb_t)(unsigned long long sym_addr, char sym_type, + const char *sym_name, void *ctx); + +int libbpf_kallsyms_parse(kallsyms_cb_t cb, void *arg); + /* handle direct returned errors */ static inline int libbpf_err(int ret) { From 5117c26e877352bcabd4871e6bcdebed4857a88d Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 16 Mar 2022 13:24:14 +0100 Subject: [PATCH 08/13] libbpf: Add bpf_link_create support for multi kprobes Adding new kprobe_multi struct to bpf_link_create_opts object to pass multiple kprobe data to link_create attr uapi. Signed-off-by: Jiri Olsa Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20220316122419.933957-9-jolsa@kernel.org --- tools/lib/bpf/bpf.c | 9 +++++++++ tools/lib/bpf/bpf.h | 9 ++++++++- 2 files changed, 17 insertions(+), 1 deletion(-) diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index f69ce3a013859..cf27251adb92e 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -854,6 +854,15 @@ int bpf_link_create(int prog_fd, int target_fd, if (!OPTS_ZEROED(opts, perf_event)) return libbpf_err(-EINVAL); break; + case BPF_TRACE_KPROBE_MULTI: + attr.link_create.kprobe_multi.flags = OPTS_GET(opts, kprobe_multi.flags, 0); + attr.link_create.kprobe_multi.cnt = OPTS_GET(opts, kprobe_multi.cnt, 0); + attr.link_create.kprobe_multi.syms = ptr_to_u64(OPTS_GET(opts, kprobe_multi.syms, 0)); + attr.link_create.kprobe_multi.addrs = ptr_to_u64(OPTS_GET(opts, kprobe_multi.addrs, 0)); + attr.link_create.kprobe_multi.cookies = ptr_to_u64(OPTS_GET(opts, kprobe_multi.cookies, 0)); + if (!OPTS_ZEROED(opts, kprobe_multi)) + return libbpf_err(-EINVAL); + break; default: if (!OPTS_ZEROED(opts, flags)) return libbpf_err(-EINVAL); diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h index 5253cb4a4c0a6..f4b4afb6d4ba7 100644 --- a/tools/lib/bpf/bpf.h +++ b/tools/lib/bpf/bpf.h @@ -413,10 +413,17 @@ struct bpf_link_create_opts { struct { __u64 bpf_cookie; } perf_event; + struct { + __u32 flags; + __u32 cnt; + const char **syms; + const unsigned long *addrs; + const __u64 *cookies; + } kprobe_multi; }; size_t :0; }; -#define bpf_link_create_opts__last_field perf_event +#define bpf_link_create_opts__last_field kprobe_multi.cookies LIBBPF_API int bpf_link_create(int prog_fd, int target_fd, enum bpf_attach_type attach_type, From ddc6b04989eb099368d3e6b6eaf5a6b181a36f91 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 16 Mar 2022 13:24:15 +0100 Subject: [PATCH 09/13] libbpf: Add bpf_program__attach_kprobe_multi_opts function Adding bpf_program__attach_kprobe_multi_opts function for attaching kprobe program to multiple functions. struct bpf_link * bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, const char *pattern, const struct bpf_kprobe_multi_opts *opts); User can specify functions to attach with 'pattern' argument that allows wildcards (*?' supported) or provide symbols or addresses directly through opts argument. These 3 options are mutually exclusive. When using symbols or addresses, user can also provide cookie value for each symbol/address that can be retrieved later in bpf program with bpf_get_attach_cookie helper. struct bpf_kprobe_multi_opts { size_t sz; const char **syms; const unsigned long *addrs; const __u64 *cookies; size_t cnt; bool retprobe; size_t :0; }; Symbols, addresses and cookies are provided through opts object (syms/addrs/cookies) as array pointers with specified count (cnt). Each cookie value is paired with provided function address or symbol with the same array index. The program can be also attached as return probe if 'retprobe' is set. For quick usage with NULL opts argument, like: bpf_program__attach_kprobe_multi_opts(prog, "ksys_*", NULL) the 'prog' will be attached as kprobe to 'ksys_*' functions. Also adding new program sections for automatic attachment: kprobe.multi/ kretprobe.multi/ The symbol_pattern is used as 'pattern' argument in bpf_program__attach_kprobe_multi_opts function. Signed-off-by: Jiri Olsa Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20220316122419.933957-10-jolsa@kernel.org --- tools/lib/bpf/libbpf.c | 160 +++++++++++++++++++++++++++++++++++++++ tools/lib/bpf/libbpf.h | 23 ++++++ tools/lib/bpf/libbpf.map | 1 + 3 files changed, 184 insertions(+) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 1ca520a29fdbc..f3a31478e23b7 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -8610,6 +8610,7 @@ static int attach_kprobe(const struct bpf_program *prog, long cookie, struct bpf static int attach_tp(const struct bpf_program *prog, long cookie, struct bpf_link **link); static int attach_raw_tp(const struct bpf_program *prog, long cookie, struct bpf_link **link); static int attach_trace(const struct bpf_program *prog, long cookie, struct bpf_link **link); +static int attach_kprobe_multi(const struct bpf_program *prog, long cookie, struct bpf_link **link); static int attach_lsm(const struct bpf_program *prog, long cookie, struct bpf_link **link); static int attach_iter(const struct bpf_program *prog, long cookie, struct bpf_link **link); @@ -8621,6 +8622,8 @@ static const struct bpf_sec_def section_defs[] = { SEC_DEF("uprobe/", KPROBE, 0, SEC_NONE), SEC_DEF("kretprobe/", KPROBE, 0, SEC_NONE, attach_kprobe), SEC_DEF("uretprobe/", KPROBE, 0, SEC_NONE), + SEC_DEF("kprobe.multi/", KPROBE, BPF_TRACE_KPROBE_MULTI, SEC_NONE, attach_kprobe_multi), + SEC_DEF("kretprobe.multi/", KPROBE, BPF_TRACE_KPROBE_MULTI, SEC_NONE, attach_kprobe_multi), SEC_DEF("tc", SCHED_CLS, 0, SEC_NONE), SEC_DEF("classifier", SCHED_CLS, 0, SEC_NONE | SEC_SLOPPY_PFX | SEC_DEPRECATED), SEC_DEF("action", SCHED_ACT, 0, SEC_NONE | SEC_SLOPPY_PFX), @@ -10224,6 +10227,139 @@ struct bpf_link *bpf_program__attach_kprobe(const struct bpf_program *prog, return bpf_program__attach_kprobe_opts(prog, func_name, &opts); } +/* Adapted from perf/util/string.c */ +static bool glob_match(const char *str, const char *pat) +{ + while (*str && *pat && *pat != '*') { + if (*pat == '?') { /* Matches any single character */ + str++; + pat++; + continue; + } + if (*str != *pat) + return false; + str++; + pat++; + } + /* Check wild card */ + if (*pat == '*') { + while (*pat == '*') + pat++; + if (!*pat) /* Tail wild card matches all */ + return true; + while (*str) + if (glob_match(str++, pat)) + return true; + } + return !*str && !*pat; +} + +struct kprobe_multi_resolve { + const char *pattern; + unsigned long *addrs; + size_t cap; + size_t cnt; +}; + +static int +resolve_kprobe_multi_cb(unsigned long long sym_addr, char sym_type, + const char *sym_name, void *ctx) +{ + struct kprobe_multi_resolve *res = ctx; + int err; + + if (!glob_match(sym_name, res->pattern)) + return 0; + + err = libbpf_ensure_mem((void **) &res->addrs, &res->cap, sizeof(unsigned long), + res->cnt + 1); + if (err) + return err; + + res->addrs[res->cnt++] = (unsigned long) sym_addr; + return 0; +} + +struct bpf_link * +bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, + const char *pattern, + const struct bpf_kprobe_multi_opts *opts) +{ + LIBBPF_OPTS(bpf_link_create_opts, lopts); + struct kprobe_multi_resolve res = { + .pattern = pattern, + }; + struct bpf_link *link = NULL; + char errmsg[STRERR_BUFSIZE]; + const unsigned long *addrs; + int err, link_fd, prog_fd; + const __u64 *cookies; + const char **syms; + bool retprobe; + size_t cnt; + + if (!OPTS_VALID(opts, bpf_kprobe_multi_opts)) + return libbpf_err_ptr(-EINVAL); + + syms = OPTS_GET(opts, syms, false); + addrs = OPTS_GET(opts, addrs, false); + cnt = OPTS_GET(opts, cnt, false); + cookies = OPTS_GET(opts, cookies, false); + + if (!pattern && !addrs && !syms) + return libbpf_err_ptr(-EINVAL); + if (pattern && (addrs || syms || cookies || cnt)) + return libbpf_err_ptr(-EINVAL); + if (!pattern && !cnt) + return libbpf_err_ptr(-EINVAL); + if (addrs && syms) + return libbpf_err_ptr(-EINVAL); + + if (pattern) { + err = libbpf_kallsyms_parse(resolve_kprobe_multi_cb, &res); + if (err) + goto error; + if (!res.cnt) { + err = -ENOENT; + goto error; + } + addrs = res.addrs; + cnt = res.cnt; + } + + retprobe = OPTS_GET(opts, retprobe, false); + + lopts.kprobe_multi.syms = syms; + lopts.kprobe_multi.addrs = addrs; + lopts.kprobe_multi.cookies = cookies; + lopts.kprobe_multi.cnt = cnt; + lopts.kprobe_multi.flags = retprobe ? BPF_F_KPROBE_MULTI_RETURN : 0; + + link = calloc(1, sizeof(*link)); + if (!link) { + err = -ENOMEM; + goto error; + } + link->detach = &bpf_link__detach_fd; + + prog_fd = bpf_program__fd(prog); + link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_KPROBE_MULTI, &lopts); + if (link_fd < 0) { + err = -errno; + pr_warn("prog '%s': failed to attach: %s\n", + prog->name, libbpf_strerror_r(err, errmsg, sizeof(errmsg))); + goto error; + } + link->fd = link_fd; + free(res.addrs); + return link; + +error: + free(link); + free(res.addrs); + return libbpf_err_ptr(err); +} + static int attach_kprobe(const struct bpf_program *prog, long cookie, struct bpf_link **link) { DECLARE_LIBBPF_OPTS(bpf_kprobe_opts, opts); @@ -10255,6 +10391,30 @@ static int attach_kprobe(const struct bpf_program *prog, long cookie, struct bpf return libbpf_get_error(*link); } +static int attach_kprobe_multi(const struct bpf_program *prog, long cookie, struct bpf_link **link) +{ + LIBBPF_OPTS(bpf_kprobe_multi_opts, opts); + const char *spec; + char *pattern; + int n; + + opts.retprobe = str_has_pfx(prog->sec_name, "kretprobe.multi/"); + if (opts.retprobe) + spec = prog->sec_name + sizeof("kretprobe.multi/") - 1; + else + spec = prog->sec_name + sizeof("kprobe.multi/") - 1; + + n = sscanf(spec, "%m[a-zA-Z0-9_.*?]", &pattern); + if (n < 1) { + pr_warn("kprobe multi pattern is invalid: %s\n", pattern); + return -EINVAL; + } + + *link = bpf_program__attach_kprobe_multi_opts(prog, pattern, &opts); + free(pattern); + return libbpf_get_error(*link); +} + static void gen_uprobe_legacy_event_name(char *buf, size_t buf_sz, const char *binary_path, uint64_t offset) { diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index c1b0c2ef14d85..d5239fb4abdc9 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -425,6 +425,29 @@ bpf_program__attach_kprobe_opts(const struct bpf_program *prog, const char *func_name, const struct bpf_kprobe_opts *opts); +struct bpf_kprobe_multi_opts { + /* size of this struct, for forward/backward compatibility */ + size_t sz; + /* array of function symbols to attach */ + const char **syms; + /* array of function addresses to attach */ + const unsigned long *addrs; + /* array of user-provided values fetchable through bpf_get_attach_cookie */ + const __u64 *cookies; + /* number of elements in syms/addrs/cookies arrays */ + size_t cnt; + /* create return kprobes */ + bool retprobe; + size_t :0; +}; + +#define bpf_kprobe_multi_opts__last_field retprobe + +LIBBPF_API struct bpf_link * +bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, + const char *pattern, + const struct bpf_kprobe_multi_opts *opts); + struct bpf_uprobe_opts { /* size of this struct, for forward/backward compatiblity */ size_t sz; diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index df1b947792c86..554c56e6e5d33 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -444,4 +444,5 @@ LIBBPF_0.8.0 { global: libbpf_register_prog_handler; libbpf_unregister_prog_handler; + bpf_program__attach_kprobe_multi_opts; } LIBBPF_0.7.0; From f7a11eeccb11185437f4da1c80b66b857d1e906f Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 16 Mar 2022 13:24:16 +0100 Subject: [PATCH 10/13] selftests/bpf: Add kprobe_multi attach test Adding kprobe_multi attach test that uses new fprobe interface to attach kprobe program to multiple functions. The test is attaching programs to bpf_fentry_test* functions and uses single trampoline program bpf_prog_test_run to trigger bpf_fentry_test* functions. Signed-off-by: Jiri Olsa Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20220316122419.933957-11-jolsa@kernel.org --- .../bpf/prog_tests/kprobe_multi_test.c | 141 ++++++++++++++++++ .../selftests/bpf/progs/kprobe_multi.c | 95 ++++++++++++ tools/testing/selftests/bpf/trace_helpers.c | 7 + 3 files changed, 243 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c create mode 100644 tools/testing/selftests/bpf/progs/kprobe_multi.c diff --git a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c new file mode 100644 index 0000000000000..ded6b8c8ec055 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c @@ -0,0 +1,141 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include "kprobe_multi.skel.h" +#include "trace_helpers.h" + +static void kprobe_multi_test_run(struct kprobe_multi *skel) +{ + LIBBPF_OPTS(bpf_test_run_opts, topts); + int err, prog_fd; + + prog_fd = bpf_program__fd(skel->progs.trigger); + err = bpf_prog_test_run_opts(prog_fd, &topts); + ASSERT_OK(err, "test_run"); + ASSERT_EQ(topts.retval, 0, "test_run"); + + ASSERT_EQ(skel->bss->kprobe_test1_result, 1, "kprobe_test1_result"); + ASSERT_EQ(skel->bss->kprobe_test2_result, 1, "kprobe_test2_result"); + ASSERT_EQ(skel->bss->kprobe_test3_result, 1, "kprobe_test3_result"); + ASSERT_EQ(skel->bss->kprobe_test4_result, 1, "kprobe_test4_result"); + ASSERT_EQ(skel->bss->kprobe_test5_result, 1, "kprobe_test5_result"); + ASSERT_EQ(skel->bss->kprobe_test6_result, 1, "kprobe_test6_result"); + ASSERT_EQ(skel->bss->kprobe_test7_result, 1, "kprobe_test7_result"); + ASSERT_EQ(skel->bss->kprobe_test8_result, 1, "kprobe_test8_result"); + + ASSERT_EQ(skel->bss->kretprobe_test1_result, 1, "kretprobe_test1_result"); + ASSERT_EQ(skel->bss->kretprobe_test2_result, 1, "kretprobe_test2_result"); + ASSERT_EQ(skel->bss->kretprobe_test3_result, 1, "kretprobe_test3_result"); + ASSERT_EQ(skel->bss->kretprobe_test4_result, 1, "kretprobe_test4_result"); + ASSERT_EQ(skel->bss->kretprobe_test5_result, 1, "kretprobe_test5_result"); + ASSERT_EQ(skel->bss->kretprobe_test6_result, 1, "kretprobe_test6_result"); + ASSERT_EQ(skel->bss->kretprobe_test7_result, 1, "kretprobe_test7_result"); + ASSERT_EQ(skel->bss->kretprobe_test8_result, 1, "kretprobe_test8_result"); +} + +static void test_skel_api(void) +{ + struct kprobe_multi *skel = NULL; + int err; + + skel = kprobe_multi__open_and_load(); + if (!ASSERT_OK_PTR(skel, "kprobe_multi__open_and_load")) + goto cleanup; + + skel->bss->pid = getpid(); + err = kprobe_multi__attach(skel); + if (!ASSERT_OK(err, "kprobe_multi__attach")) + goto cleanup; + + kprobe_multi_test_run(skel); + +cleanup: + kprobe_multi__destroy(skel); +} + +static void test_link_api(struct bpf_link_create_opts *opts) +{ + int prog_fd, link1_fd = -1, link2_fd = -1; + struct kprobe_multi *skel = NULL; + + skel = kprobe_multi__open_and_load(); + if (!ASSERT_OK_PTR(skel, "fentry_raw_skel_load")) + goto cleanup; + + skel->bss->pid = getpid(); + prog_fd = bpf_program__fd(skel->progs.test_kprobe); + link1_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_KPROBE_MULTI, opts); + if (!ASSERT_GE(link1_fd, 0, "link_fd")) + goto cleanup; + + opts->kprobe_multi.flags = BPF_F_KPROBE_MULTI_RETURN; + prog_fd = bpf_program__fd(skel->progs.test_kretprobe); + link2_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_KPROBE_MULTI, opts); + if (!ASSERT_GE(link2_fd, 0, "link_fd")) + goto cleanup; + + kprobe_multi_test_run(skel); + +cleanup: + if (link1_fd != -1) + close(link1_fd); + if (link2_fd != -1) + close(link2_fd); + kprobe_multi__destroy(skel); +} + +#define GET_ADDR(__sym, __addr) ({ \ + __addr = ksym_get_addr(__sym); \ + if (!ASSERT_NEQ(__addr, 0, "kallsyms load failed for " #__sym)) \ + return; \ +}) + +static void test_link_api_addrs(void) +{ + LIBBPF_OPTS(bpf_link_create_opts, opts); + unsigned long long addrs[8]; + + GET_ADDR("bpf_fentry_test1", addrs[0]); + GET_ADDR("bpf_fentry_test2", addrs[1]); + GET_ADDR("bpf_fentry_test3", addrs[2]); + GET_ADDR("bpf_fentry_test4", addrs[3]); + GET_ADDR("bpf_fentry_test5", addrs[4]); + GET_ADDR("bpf_fentry_test6", addrs[5]); + GET_ADDR("bpf_fentry_test7", addrs[6]); + GET_ADDR("bpf_fentry_test8", addrs[7]); + + opts.kprobe_multi.addrs = (const unsigned long*) addrs; + opts.kprobe_multi.cnt = ARRAY_SIZE(addrs); + test_link_api(&opts); +} + +static void test_link_api_syms(void) +{ + LIBBPF_OPTS(bpf_link_create_opts, opts); + const char *syms[8] = { + "bpf_fentry_test1", + "bpf_fentry_test2", + "bpf_fentry_test3", + "bpf_fentry_test4", + "bpf_fentry_test5", + "bpf_fentry_test6", + "bpf_fentry_test7", + "bpf_fentry_test8", + }; + + opts.kprobe_multi.syms = syms; + opts.kprobe_multi.cnt = ARRAY_SIZE(syms); + test_link_api(&opts); +} + +void test_kprobe_multi_test(void) +{ + if (!ASSERT_OK(load_kallsyms(), "load_kallsyms")) + return; + + if (test__start_subtest("skel_api")) + test_skel_api(); + if (test__start_subtest("link_api_addrs")) + test_link_api_syms(); + if (test__start_subtest("link_api_syms")) + test_link_api_addrs(); +} diff --git a/tools/testing/selftests/bpf/progs/kprobe_multi.c b/tools/testing/selftests/bpf/progs/kprobe_multi.c new file mode 100644 index 0000000000000..6616c082c8c2c --- /dev/null +++ b/tools/testing/selftests/bpf/progs/kprobe_multi.c @@ -0,0 +1,95 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include + +char _license[] SEC("license") = "GPL"; + +extern const void bpf_fentry_test1 __ksym; +extern const void bpf_fentry_test2 __ksym; +extern const void bpf_fentry_test3 __ksym; +extern const void bpf_fentry_test4 __ksym; +extern const void bpf_fentry_test5 __ksym; +extern const void bpf_fentry_test6 __ksym; +extern const void bpf_fentry_test7 __ksym; +extern const void bpf_fentry_test8 __ksym; + +int pid = 0; + +__u64 kprobe_test1_result = 0; +__u64 kprobe_test2_result = 0; +__u64 kprobe_test3_result = 0; +__u64 kprobe_test4_result = 0; +__u64 kprobe_test5_result = 0; +__u64 kprobe_test6_result = 0; +__u64 kprobe_test7_result = 0; +__u64 kprobe_test8_result = 0; + +__u64 kretprobe_test1_result = 0; +__u64 kretprobe_test2_result = 0; +__u64 kretprobe_test3_result = 0; +__u64 kretprobe_test4_result = 0; +__u64 kretprobe_test5_result = 0; +__u64 kretprobe_test6_result = 0; +__u64 kretprobe_test7_result = 0; +__u64 kretprobe_test8_result = 0; + +static void kprobe_multi_check(void *ctx, bool is_return) +{ + if (bpf_get_current_pid_tgid() >> 32 != pid) + return; + + __u64 addr = bpf_get_func_ip(ctx); + +#define SET(__var, __addr) ({ \ + if ((const void *) addr == __addr) \ + __var = 1; \ +}) + + if (is_return) { + SET(kretprobe_test1_result, &bpf_fentry_test1); + SET(kretprobe_test2_result, &bpf_fentry_test2); + SET(kretprobe_test3_result, &bpf_fentry_test3); + SET(kretprobe_test4_result, &bpf_fentry_test4); + SET(kretprobe_test5_result, &bpf_fentry_test5); + SET(kretprobe_test6_result, &bpf_fentry_test6); + SET(kretprobe_test7_result, &bpf_fentry_test7); + SET(kretprobe_test8_result, &bpf_fentry_test8); + } else { + SET(kprobe_test1_result, &bpf_fentry_test1); + SET(kprobe_test2_result, &bpf_fentry_test2); + SET(kprobe_test3_result, &bpf_fentry_test3); + SET(kprobe_test4_result, &bpf_fentry_test4); + SET(kprobe_test5_result, &bpf_fentry_test5); + SET(kprobe_test6_result, &bpf_fentry_test6); + SET(kprobe_test7_result, &bpf_fentry_test7); + SET(kprobe_test8_result, &bpf_fentry_test8); + } + +#undef SET +} + +/* + * No tests in here, just to trigger 'bpf_fentry_test*' + * through tracing test_run + */ +SEC("fentry/bpf_modify_return_test") +int BPF_PROG(trigger) +{ + return 0; +} + +SEC("kprobe.multi/bpf_fentry_tes??") +int test_kprobe(struct pt_regs *ctx) +{ + kprobe_multi_check(ctx, false); + return 0; +} + +SEC("kretprobe.multi/bpf_fentry_test*") +int test_kretprobe(struct pt_regs *ctx) +{ + kprobe_multi_check(ctx, true); + return 0; +} diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c index ca6abae9b09cb..3d6217e3aff7a 100644 --- a/tools/testing/selftests/bpf/trace_helpers.c +++ b/tools/testing/selftests/bpf/trace_helpers.c @@ -34,6 +34,13 @@ int load_kallsyms(void) if (!f) return -ENOENT; + /* + * This is called/used from multiplace places, + * load symbols just once. + */ + if (sym_cnt) + return 0; + while (fgets(buf, sizeof(buf), f)) { if (sscanf(buf, "%p %c %s", &addr, &symbol, func) != 3) break; From 2c6401c966ae1fbe07eb3b8a07256dc41b596928 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 16 Mar 2022 13:24:17 +0100 Subject: [PATCH 11/13] selftests/bpf: Add kprobe_multi bpf_cookie test Adding bpf_cookie test for programs attached by kprobe_multi links. Signed-off-by: Jiri Olsa Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20220316122419.933957-12-jolsa@kernel.org --- .../selftests/bpf/prog_tests/bpf_cookie.c | 109 ++++++++++++++++++ .../selftests/bpf/progs/kprobe_multi.c | 41 ++++--- 2 files changed, 131 insertions(+), 19 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c b/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c index 0612e79a92812..6671d4dc0b5d6 100644 --- a/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c +++ b/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c @@ -7,6 +7,7 @@ #include #include #include "test_bpf_cookie.skel.h" +#include "kprobe_multi.skel.h" /* uprobe attach point */ static void trigger_func(void) @@ -63,6 +64,112 @@ static void kprobe_subtest(struct test_bpf_cookie *skel) bpf_link__destroy(retlink2); } +static void kprobe_multi_test_run(struct kprobe_multi *skel) +{ + LIBBPF_OPTS(bpf_test_run_opts, topts); + int err, prog_fd; + + prog_fd = bpf_program__fd(skel->progs.trigger); + err = bpf_prog_test_run_opts(prog_fd, &topts); + ASSERT_OK(err, "test_run"); + ASSERT_EQ(topts.retval, 0, "test_run"); + + ASSERT_EQ(skel->bss->kprobe_test1_result, 1, "kprobe_test1_result"); + ASSERT_EQ(skel->bss->kprobe_test2_result, 1, "kprobe_test2_result"); + ASSERT_EQ(skel->bss->kprobe_test3_result, 1, "kprobe_test3_result"); + ASSERT_EQ(skel->bss->kprobe_test4_result, 1, "kprobe_test4_result"); + ASSERT_EQ(skel->bss->kprobe_test5_result, 1, "kprobe_test5_result"); + ASSERT_EQ(skel->bss->kprobe_test6_result, 1, "kprobe_test6_result"); + ASSERT_EQ(skel->bss->kprobe_test7_result, 1, "kprobe_test7_result"); + ASSERT_EQ(skel->bss->kprobe_test8_result, 1, "kprobe_test8_result"); + + ASSERT_EQ(skel->bss->kretprobe_test1_result, 1, "kretprobe_test1_result"); + ASSERT_EQ(skel->bss->kretprobe_test2_result, 1, "kretprobe_test2_result"); + ASSERT_EQ(skel->bss->kretprobe_test3_result, 1, "kretprobe_test3_result"); + ASSERT_EQ(skel->bss->kretprobe_test4_result, 1, "kretprobe_test4_result"); + ASSERT_EQ(skel->bss->kretprobe_test5_result, 1, "kretprobe_test5_result"); + ASSERT_EQ(skel->bss->kretprobe_test6_result, 1, "kretprobe_test6_result"); + ASSERT_EQ(skel->bss->kretprobe_test7_result, 1, "kretprobe_test7_result"); + ASSERT_EQ(skel->bss->kretprobe_test8_result, 1, "kretprobe_test8_result"); +} + +static void kprobe_multi_link_api_subtest(void) +{ + int prog_fd, link1_fd = -1, link2_fd = -1; + struct kprobe_multi *skel = NULL; + LIBBPF_OPTS(bpf_link_create_opts, opts); + unsigned long long addrs[8]; + __u64 cookies[8]; + + if (!ASSERT_OK(load_kallsyms(), "load_kallsyms")) + goto cleanup; + + skel = kprobe_multi__open_and_load(); + if (!ASSERT_OK_PTR(skel, "fentry_raw_skel_load")) + goto cleanup; + + skel->bss->pid = getpid(); + skel->bss->test_cookie = true; + +#define GET_ADDR(__sym, __addr) ({ \ + __addr = ksym_get_addr(__sym); \ + if (!ASSERT_NEQ(__addr, 0, "ksym_get_addr " #__sym)) \ + goto cleanup; \ +}) + + GET_ADDR("bpf_fentry_test1", addrs[0]); + GET_ADDR("bpf_fentry_test2", addrs[1]); + GET_ADDR("bpf_fentry_test3", addrs[2]); + GET_ADDR("bpf_fentry_test4", addrs[3]); + GET_ADDR("bpf_fentry_test5", addrs[4]); + GET_ADDR("bpf_fentry_test6", addrs[5]); + GET_ADDR("bpf_fentry_test7", addrs[6]); + GET_ADDR("bpf_fentry_test8", addrs[7]); + +#undef GET_ADDR + + cookies[0] = 1; + cookies[1] = 2; + cookies[2] = 3; + cookies[3] = 4; + cookies[4] = 5; + cookies[5] = 6; + cookies[6] = 7; + cookies[7] = 8; + + opts.kprobe_multi.addrs = (const unsigned long *) &addrs; + opts.kprobe_multi.cnt = ARRAY_SIZE(addrs); + opts.kprobe_multi.cookies = (const __u64 *) &cookies; + prog_fd = bpf_program__fd(skel->progs.test_kprobe); + + link1_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_KPROBE_MULTI, &opts); + if (!ASSERT_GE(link1_fd, 0, "link1_fd")) + goto cleanup; + + cookies[0] = 8; + cookies[1] = 7; + cookies[2] = 6; + cookies[3] = 5; + cookies[4] = 4; + cookies[5] = 3; + cookies[6] = 2; + cookies[7] = 1; + + opts.kprobe_multi.flags = BPF_F_KPROBE_MULTI_RETURN; + prog_fd = bpf_program__fd(skel->progs.test_kretprobe); + + link2_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_KPROBE_MULTI, &opts); + if (!ASSERT_GE(link2_fd, 0, "link2_fd")) + goto cleanup; + + kprobe_multi_test_run(skel); + +cleanup: + close(link1_fd); + close(link2_fd); + kprobe_multi__destroy(skel); +} + static void uprobe_subtest(struct test_bpf_cookie *skel) { DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, opts); @@ -249,6 +356,8 @@ void test_bpf_cookie(void) if (test__start_subtest("kprobe")) kprobe_subtest(skel); + if (test__start_subtest("multi_kprobe_link_api")) + kprobe_multi_link_api_subtest(); if (test__start_subtest("uprobe")) uprobe_subtest(skel); if (test__start_subtest("tracepoint")) diff --git a/tools/testing/selftests/bpf/progs/kprobe_multi.c b/tools/testing/selftests/bpf/progs/kprobe_multi.c index 6616c082c8c2c..af27d2c6fce8d 100644 --- a/tools/testing/selftests/bpf/progs/kprobe_multi.c +++ b/tools/testing/selftests/bpf/progs/kprobe_multi.c @@ -16,6 +16,7 @@ extern const void bpf_fentry_test7 __ksym; extern const void bpf_fentry_test8 __ksym; int pid = 0; +bool test_cookie = false; __u64 kprobe_test1_result = 0; __u64 kprobe_test2_result = 0; @@ -40,31 +41,33 @@ static void kprobe_multi_check(void *ctx, bool is_return) if (bpf_get_current_pid_tgid() >> 32 != pid) return; + __u64 cookie = test_cookie ? bpf_get_attach_cookie(ctx) : 0; __u64 addr = bpf_get_func_ip(ctx); -#define SET(__var, __addr) ({ \ - if ((const void *) addr == __addr) \ - __var = 1; \ +#define SET(__var, __addr, __cookie) ({ \ + if (((const void *) addr == __addr) && \ + (!test_cookie || (cookie == __cookie))) \ + __var = 1; \ }) if (is_return) { - SET(kretprobe_test1_result, &bpf_fentry_test1); - SET(kretprobe_test2_result, &bpf_fentry_test2); - SET(kretprobe_test3_result, &bpf_fentry_test3); - SET(kretprobe_test4_result, &bpf_fentry_test4); - SET(kretprobe_test5_result, &bpf_fentry_test5); - SET(kretprobe_test6_result, &bpf_fentry_test6); - SET(kretprobe_test7_result, &bpf_fentry_test7); - SET(kretprobe_test8_result, &bpf_fentry_test8); + SET(kretprobe_test1_result, &bpf_fentry_test1, 8); + SET(kretprobe_test2_result, &bpf_fentry_test2, 7); + SET(kretprobe_test3_result, &bpf_fentry_test3, 6); + SET(kretprobe_test4_result, &bpf_fentry_test4, 5); + SET(kretprobe_test5_result, &bpf_fentry_test5, 4); + SET(kretprobe_test6_result, &bpf_fentry_test6, 3); + SET(kretprobe_test7_result, &bpf_fentry_test7, 2); + SET(kretprobe_test8_result, &bpf_fentry_test8, 1); } else { - SET(kprobe_test1_result, &bpf_fentry_test1); - SET(kprobe_test2_result, &bpf_fentry_test2); - SET(kprobe_test3_result, &bpf_fentry_test3); - SET(kprobe_test4_result, &bpf_fentry_test4); - SET(kprobe_test5_result, &bpf_fentry_test5); - SET(kprobe_test6_result, &bpf_fentry_test6); - SET(kprobe_test7_result, &bpf_fentry_test7); - SET(kprobe_test8_result, &bpf_fentry_test8); + SET(kprobe_test1_result, &bpf_fentry_test1, 1); + SET(kprobe_test2_result, &bpf_fentry_test2, 2); + SET(kprobe_test3_result, &bpf_fentry_test3, 3); + SET(kprobe_test4_result, &bpf_fentry_test4, 4); + SET(kprobe_test5_result, &bpf_fentry_test5, 5); + SET(kprobe_test6_result, &bpf_fentry_test6, 6); + SET(kprobe_test7_result, &bpf_fentry_test7, 7); + SET(kprobe_test8_result, &bpf_fentry_test8, 8); } #undef SET From 9271a0c7ae7a914782759d8fe22ef28fffab82fe Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 16 Mar 2022 13:24:18 +0100 Subject: [PATCH 12/13] selftests/bpf: Add attach test for bpf_program__attach_kprobe_multi_opts Adding tests for bpf_program__attach_kprobe_multi_opts function, that test attach with pattern, symbols and addrs. Signed-off-by: Jiri Olsa Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20220316122419.933957-13-jolsa@kernel.org --- .../bpf/prog_tests/kprobe_multi_test.c | 204 +++++++++++++++++- 1 file changed, 193 insertions(+), 11 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c index ded6b8c8ec055..b9876b55fc0c8 100644 --- a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c +++ b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c @@ -3,7 +3,7 @@ #include "kprobe_multi.skel.h" #include "trace_helpers.h" -static void kprobe_multi_test_run(struct kprobe_multi *skel) +static void kprobe_multi_test_run(struct kprobe_multi *skel, bool test_return) { LIBBPF_OPTS(bpf_test_run_opts, topts); int err, prog_fd; @@ -22,14 +22,16 @@ static void kprobe_multi_test_run(struct kprobe_multi *skel) ASSERT_EQ(skel->bss->kprobe_test7_result, 1, "kprobe_test7_result"); ASSERT_EQ(skel->bss->kprobe_test8_result, 1, "kprobe_test8_result"); - ASSERT_EQ(skel->bss->kretprobe_test1_result, 1, "kretprobe_test1_result"); - ASSERT_EQ(skel->bss->kretprobe_test2_result, 1, "kretprobe_test2_result"); - ASSERT_EQ(skel->bss->kretprobe_test3_result, 1, "kretprobe_test3_result"); - ASSERT_EQ(skel->bss->kretprobe_test4_result, 1, "kretprobe_test4_result"); - ASSERT_EQ(skel->bss->kretprobe_test5_result, 1, "kretprobe_test5_result"); - ASSERT_EQ(skel->bss->kretprobe_test6_result, 1, "kretprobe_test6_result"); - ASSERT_EQ(skel->bss->kretprobe_test7_result, 1, "kretprobe_test7_result"); - ASSERT_EQ(skel->bss->kretprobe_test8_result, 1, "kretprobe_test8_result"); + if (test_return) { + ASSERT_EQ(skel->bss->kretprobe_test1_result, 1, "kretprobe_test1_result"); + ASSERT_EQ(skel->bss->kretprobe_test2_result, 1, "kretprobe_test2_result"); + ASSERT_EQ(skel->bss->kretprobe_test3_result, 1, "kretprobe_test3_result"); + ASSERT_EQ(skel->bss->kretprobe_test4_result, 1, "kretprobe_test4_result"); + ASSERT_EQ(skel->bss->kretprobe_test5_result, 1, "kretprobe_test5_result"); + ASSERT_EQ(skel->bss->kretprobe_test6_result, 1, "kretprobe_test6_result"); + ASSERT_EQ(skel->bss->kretprobe_test7_result, 1, "kretprobe_test7_result"); + ASSERT_EQ(skel->bss->kretprobe_test8_result, 1, "kretprobe_test8_result"); + } } static void test_skel_api(void) @@ -46,7 +48,7 @@ static void test_skel_api(void) if (!ASSERT_OK(err, "kprobe_multi__attach")) goto cleanup; - kprobe_multi_test_run(skel); + kprobe_multi_test_run(skel, true); cleanup: kprobe_multi__destroy(skel); @@ -73,7 +75,7 @@ static void test_link_api(struct bpf_link_create_opts *opts) if (!ASSERT_GE(link2_fd, 0, "link_fd")) goto cleanup; - kprobe_multi_test_run(skel); + kprobe_multi_test_run(skel, true); cleanup: if (link1_fd != -1) @@ -127,6 +129,178 @@ static void test_link_api_syms(void) test_link_api(&opts); } +static void +test_attach_api(const char *pattern, struct bpf_kprobe_multi_opts *opts) +{ + struct bpf_link *link1 = NULL, *link2 = NULL; + struct kprobe_multi *skel = NULL; + + skel = kprobe_multi__open_and_load(); + if (!ASSERT_OK_PTR(skel, "fentry_raw_skel_load")) + goto cleanup; + + skel->bss->pid = getpid(); + link1 = bpf_program__attach_kprobe_multi_opts(skel->progs.test_kprobe, + pattern, opts); + if (!ASSERT_OK_PTR(link1, "bpf_program__attach_kprobe_multi_opts")) + goto cleanup; + + if (opts) { + opts->retprobe = true; + link2 = bpf_program__attach_kprobe_multi_opts(skel->progs.test_kretprobe, + pattern, opts); + if (!ASSERT_OK_PTR(link2, "bpf_program__attach_kprobe_multi_opts")) + goto cleanup; + } + + kprobe_multi_test_run(skel, !!opts); + +cleanup: + bpf_link__destroy(link2); + bpf_link__destroy(link1); + kprobe_multi__destroy(skel); +} + +static void test_attach_api_pattern(void) +{ + LIBBPF_OPTS(bpf_kprobe_multi_opts, opts); + + test_attach_api("bpf_fentry_test*", &opts); + test_attach_api("bpf_fentry_test?", NULL); +} + +static void test_attach_api_addrs(void) +{ + LIBBPF_OPTS(bpf_kprobe_multi_opts, opts); + unsigned long long addrs[8]; + + GET_ADDR("bpf_fentry_test1", addrs[0]); + GET_ADDR("bpf_fentry_test2", addrs[1]); + GET_ADDR("bpf_fentry_test3", addrs[2]); + GET_ADDR("bpf_fentry_test4", addrs[3]); + GET_ADDR("bpf_fentry_test5", addrs[4]); + GET_ADDR("bpf_fentry_test6", addrs[5]); + GET_ADDR("bpf_fentry_test7", addrs[6]); + GET_ADDR("bpf_fentry_test8", addrs[7]); + + opts.addrs = (const unsigned long *) addrs; + opts.cnt = ARRAY_SIZE(addrs); + test_attach_api(NULL, &opts); +} + +static void test_attach_api_syms(void) +{ + LIBBPF_OPTS(bpf_kprobe_multi_opts, opts); + const char *syms[8] = { + "bpf_fentry_test1", + "bpf_fentry_test2", + "bpf_fentry_test3", + "bpf_fentry_test4", + "bpf_fentry_test5", + "bpf_fentry_test6", + "bpf_fentry_test7", + "bpf_fentry_test8", + }; + + opts.syms = syms; + opts.cnt = ARRAY_SIZE(syms); + test_attach_api(NULL, &opts); +} + +static void test_attach_api_fails(void) +{ + LIBBPF_OPTS(bpf_kprobe_multi_opts, opts); + struct kprobe_multi *skel = NULL; + struct bpf_link *link = NULL; + unsigned long long addrs[2]; + const char *syms[2] = { + "bpf_fentry_test1", + "bpf_fentry_test2", + }; + __u64 cookies[2]; + + addrs[0] = ksym_get_addr("bpf_fentry_test1"); + addrs[1] = ksym_get_addr("bpf_fentry_test2"); + + if (!ASSERT_FALSE(!addrs[0] || !addrs[1], "ksym_get_addr")) + goto cleanup; + + skel = kprobe_multi__open_and_load(); + if (!ASSERT_OK_PTR(skel, "fentry_raw_skel_load")) + goto cleanup; + + skel->bss->pid = getpid(); + + /* fail_1 - pattern and opts NULL */ + link = bpf_program__attach_kprobe_multi_opts(skel->progs.test_kprobe, + NULL, NULL); + if (!ASSERT_ERR_PTR(link, "fail_1")) + goto cleanup; + + if (!ASSERT_EQ(libbpf_get_error(link), -EINVAL, "fail_1_error")) + goto cleanup; + + /* fail_2 - both addrs and syms set */ + opts.addrs = (const unsigned long *) addrs; + opts.syms = syms; + opts.cnt = ARRAY_SIZE(syms); + opts.cookies = NULL; + + link = bpf_program__attach_kprobe_multi_opts(skel->progs.test_kprobe, + NULL, &opts); + if (!ASSERT_ERR_PTR(link, "fail_2")) + goto cleanup; + + if (!ASSERT_EQ(libbpf_get_error(link), -EINVAL, "fail_2_error")) + goto cleanup; + + /* fail_3 - pattern and addrs set */ + opts.addrs = (const unsigned long *) addrs; + opts.syms = NULL; + opts.cnt = ARRAY_SIZE(syms); + opts.cookies = NULL; + + link = bpf_program__attach_kprobe_multi_opts(skel->progs.test_kprobe, + "ksys_*", &opts); + if (!ASSERT_ERR_PTR(link, "fail_3")) + goto cleanup; + + if (!ASSERT_EQ(libbpf_get_error(link), -EINVAL, "fail_3_error")) + goto cleanup; + + /* fail_4 - pattern and cnt set */ + opts.addrs = NULL; + opts.syms = NULL; + opts.cnt = ARRAY_SIZE(syms); + opts.cookies = NULL; + + link = bpf_program__attach_kprobe_multi_opts(skel->progs.test_kprobe, + "ksys_*", &opts); + if (!ASSERT_ERR_PTR(link, "fail_4")) + goto cleanup; + + if (!ASSERT_EQ(libbpf_get_error(link), -EINVAL, "fail_4_error")) + goto cleanup; + + /* fail_5 - pattern and cookies */ + opts.addrs = NULL; + opts.syms = NULL; + opts.cnt = 0; + opts.cookies = cookies; + + link = bpf_program__attach_kprobe_multi_opts(skel->progs.test_kprobe, + "ksys_*", &opts); + if (!ASSERT_ERR_PTR(link, "fail_5")) + goto cleanup; + + if (!ASSERT_EQ(libbpf_get_error(link), -EINVAL, "fail_5_error")) + goto cleanup; + +cleanup: + bpf_link__destroy(link); + kprobe_multi__destroy(skel); +} + void test_kprobe_multi_test(void) { if (!ASSERT_OK(load_kallsyms(), "load_kallsyms")) @@ -138,4 +312,12 @@ void test_kprobe_multi_test(void) test_link_api_syms(); if (test__start_subtest("link_api_syms")) test_link_api_addrs(); + if (test__start_subtest("attach_api_pattern")) + test_attach_api_pattern(); + if (test__start_subtest("attach_api_addrs")) + test_attach_api_addrs(); + if (test__start_subtest("attach_api_syms")) + test_attach_api_syms(); + if (test__start_subtest("attach_api_fails")) + test_attach_api_fails(); } From 318c812cebfcfdf42f254e6c1e6490a46e7714f8 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 16 Mar 2022 13:24:19 +0100 Subject: [PATCH 13/13] selftests/bpf: Add cookie test for bpf_program__attach_kprobe_multi_opts Adding bpf_cookie test for programs attached by bpf_program__attach_kprobe_multi_opts API. Signed-off-by: Jiri Olsa Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20220316122419.933957-14-jolsa@kernel.org --- .../selftests/bpf/prog_tests/bpf_cookie.c | 68 +++++++++++++++++++ 1 file changed, 68 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c b/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c index 6671d4dc0b5d6..923a6139b2d8f 100644 --- a/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c +++ b/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c @@ -170,6 +170,72 @@ static void kprobe_multi_link_api_subtest(void) kprobe_multi__destroy(skel); } +static void kprobe_multi_attach_api_subtest(void) +{ + struct bpf_link *link1 = NULL, *link2 = NULL; + LIBBPF_OPTS(bpf_kprobe_multi_opts, opts); + LIBBPF_OPTS(bpf_test_run_opts, topts); + struct kprobe_multi *skel = NULL; + const char *syms[8] = { + "bpf_fentry_test1", + "bpf_fentry_test2", + "bpf_fentry_test3", + "bpf_fentry_test4", + "bpf_fentry_test5", + "bpf_fentry_test6", + "bpf_fentry_test7", + "bpf_fentry_test8", + }; + __u64 cookies[8]; + + skel = kprobe_multi__open_and_load(); + if (!ASSERT_OK_PTR(skel, "fentry_raw_skel_load")) + goto cleanup; + + skel->bss->pid = getpid(); + skel->bss->test_cookie = true; + + cookies[0] = 1; + cookies[1] = 2; + cookies[2] = 3; + cookies[3] = 4; + cookies[4] = 5; + cookies[5] = 6; + cookies[6] = 7; + cookies[7] = 8; + + opts.syms = syms; + opts.cnt = ARRAY_SIZE(syms); + opts.cookies = cookies; + + link1 = bpf_program__attach_kprobe_multi_opts(skel->progs.test_kprobe, + NULL, &opts); + if (!ASSERT_OK_PTR(link1, "bpf_program__attach_kprobe_multi_opts")) + goto cleanup; + + cookies[0] = 8; + cookies[1] = 7; + cookies[2] = 6; + cookies[3] = 5; + cookies[4] = 4; + cookies[5] = 3; + cookies[6] = 2; + cookies[7] = 1; + + opts.retprobe = true; + + link2 = bpf_program__attach_kprobe_multi_opts(skel->progs.test_kretprobe, + NULL, &opts); + if (!ASSERT_OK_PTR(link2, "bpf_program__attach_kprobe_multi_opts")) + goto cleanup; + + kprobe_multi_test_run(skel); + +cleanup: + bpf_link__destroy(link2); + bpf_link__destroy(link1); + kprobe_multi__destroy(skel); +} static void uprobe_subtest(struct test_bpf_cookie *skel) { DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, opts); @@ -358,6 +424,8 @@ void test_bpf_cookie(void) kprobe_subtest(skel); if (test__start_subtest("multi_kprobe_link_api")) kprobe_multi_link_api_subtest(); + if (test__start_subtest("multi_kprobe_attach_api")) + kprobe_multi_attach_api_subtest(); if (test__start_subtest("uprobe")) uprobe_subtest(skel); if (test__start_subtest("tracepoint"))