diff options
author | Daniel Borkmann <daniel@iogearbox.net> | 2021-08-17 01:45:08 +0300 |
---|---|---|
committer | Daniel Borkmann <daniel@iogearbox.net> | 2021-08-17 01:45:17 +0300 |
commit | 3a4ce01b24a7b61b798dc9b106001584d0a9f43b (patch) | |
tree | 52231ab0e774f99c6e66d5ca4ca9f2ffcdefc4a3 | |
parent | 1bda52f80471260bcc7391f4e6919effedfc88d8 (diff) | |
parent | 4bd11e08e0bb1862fe72495014e33795e412bffb (diff) | |
download | linux-3a4ce01b24a7b61b798dc9b106001584d0a9f43b.tar.xz |
Merge branch 'bpf-perf-link'
Andrii Nakryiko says:
====================
This patch set implements an ability for users to specify custom black box u64
value for each BPF program attachment, bpf_cookie, which is available to BPF
program at runtime. This is a feature that's critically missing for cases when
some sort of generic processing needs to be done by the common BPF program
logic (or even exactly the same BPF program) across multiple BPF hooks (e.g.,
many uniformly handled kprobes) and it's important to be able to distinguish
between each BPF hook at runtime (e.g., for additional configuration lookup).
The choice of restricting this to a fixed-size 8-byte u64 value is an explicit
design decision. Making this configurable by users adds unnecessary complexity
(extra memory allocations, extra complications on the verifier side to validate
accesses to variable-sized data area) while not really opening up new
possibilities. If user's use case requires storing more data per attachment,
it's possible to use either global array, or ARRAY/HASHMAP BPF maps, where
bpf_cookie would be used as an index into respective storage, populated by
user-space code before creating BPF link. This gives user all the flexibility
and control while keeping BPF verifier and BPF helper API simple.
Currently, similar functionality can only be achieved through:
- code-generation and BPF program cloning, which is very complicated and
unmaintainable;
- on-the-fly C code generation and further runtime compilation, which is
what BCC uses and allows to do pretty simply. The big downside is a very
heavy-weight Clang/LLVM dependency and inefficient memory usage (due to
many BPF program clones and the compilation process itself);
- in some cases (kprobes and sometimes uprobes) it's possible to do function
IP lookup to get function-specific configuration. This doesn't work for
all the cases (e.g., when attaching uprobes to shared libraries) and has
higher runtime overhead and additional programming complexity due to
BPF_MAP_TYPE_HASHMAP lookups. Up until recently, before bpf_get_func_ip()
BPF helper was added, it was also very complicated and unstable (API-wise)
to get traced function's IP from fentry/fexit and kretprobe.
With libbpf and BPF CO-RE, runtime compilation is not an option, so to be able
to build generic tracing tooling simply and efficiently, ability to provide
additional bpf_cookie value for each *attachment* (as opposed to each BPF
program) is extremely important. Two immediate users of this functionality are
going to be libbpf-based USDT library (currently in development) and retsnoop
([0]), but I'm sure more applications will come once users get this feature in
their kernels.
To achieve above described, all perf_event-based BPF hooks are made available
through a new BPF_LINK_TYPE_PERF_EVENT BPF link, which allows to use common
LINK_CREATE command for program attachments and generally brings
perf_event-based attachments into a common BPF link infrastructure.
With that, LINK_CREATE gets ability to pass throught bpf_cookie value during
link creation (BPF program attachment) time. bpf_get_attach_cookie() BPF
helper is added to allow fetching this value at runtime from BPF program side.
BPF cookie is stored either on struct perf_event itself and fetched from the
BPF program context, or is passed through ambient BPF run context, added in
c7603cfa04e7 ("bpf: Add ambient BPF runtime context stored in current").
On the libbpf side of things, BPF perf link is utilized whenever is supported
by the kernel instead of using PERF_EVENT_IOC_SET_BPF ioctl on perf_event FD.
All the tracing attach APIs are extended with OPTS and bpf_cookie is passed
through corresponding opts structs.
Last part of the patch set adds few self-tests utilizing new APIs.
There are also a few refactorings along the way to make things cleaner and
easier to work with, both in kernel (BPF_PROG_RUN and BPF_PROG_RUN_ARRAY), and
throughout libbpf and selftests.
Follow-up patches will extend bpf_cookie to fentry/fexit programs.
While adding uprobe_opts, also extend it with ref_ctr_offset for specifying
USDT semaphore (reference counter) offset. Update attach_probe selftests to
validate its functionality. This is another feature (along with bpf_cookie)
required for implementing libbpf-based USDT solution.
[0] https://github.com/anakryiko/retsnoop
v4->v5:
- rebase on latest bpf-next to resolve merge conflict;
- add ref_ctr_offset to uprobe_opts and corresponding selftest;
v3->v4:
- get rid of BPF_PROG_RUN macro in favor of bpf_prog_run() (Daniel);
- move #ifdef CONFIG_BPF_SYSCALL check into bpf_set_run_ctx (Daniel);
v2->v3:
- user_ctx -> bpf_cookie, bpf_get_user_ctx -> bpf_get_attach_cookie (Peter);
- fix BPF_LINK_TYPE_PERF_EVENT value fix (Jiri);
- use bpf_prog_run() from bpf_prog_run_pin_on_cpu() (Yonghong);
v1->v2:
- fix build failures on non-x86 arches by gating on CONFIG_PERF_EVENTS.
====================
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
40 files changed, 1315 insertions, 357 deletions
diff --git a/Documentation/networking/filter.rst b/Documentation/networking/filter.rst index 5f13905b12e0..ce2b8e8bb9ab 100644 --- a/Documentation/networking/filter.rst +++ b/Documentation/networking/filter.rst @@ -638,8 +638,8 @@ extension, PTP dissector/classifier, and much more. They are all internally converted by the kernel into the new instruction set representation and run in the eBPF interpreter. For in-kernel handlers, this all works transparently by using bpf_prog_create() for setting up the filter, resp. -bpf_prog_destroy() for destroying it. The macro -BPF_PROG_RUN(filter, ctx) transparently invokes eBPF interpreter or JITed +bpf_prog_destroy() for destroying it. The function +bpf_prog_run(filter, ctx) transparently invokes eBPF interpreter or JITed code to run the filter. 'filter' is a pointer to struct bpf_prog that we got from bpf_prog_create(), and 'ctx' the given context (e.g. skb pointer). All constraints and restrictions from bpf_check_classic() apply diff --git a/drivers/media/rc/bpf-lirc.c b/drivers/media/rc/bpf-lirc.c index afae0afe3f81..3eff08d7b8e5 100644 --- a/drivers/media/rc/bpf-lirc.c +++ b/drivers/media/rc/bpf-lirc.c @@ -160,7 +160,7 @@ static int lirc_bpf_attach(struct rc_dev *rcdev, struct bpf_prog *prog) goto unlock; } - ret = bpf_prog_array_copy(old_array, NULL, prog, &new_array); + ret = bpf_prog_array_copy(old_array, NULL, prog, 0, &new_array); if (ret < 0) goto unlock; @@ -193,7 +193,7 @@ static int lirc_bpf_detach(struct rc_dev *rcdev, struct bpf_prog *prog) } old_array = lirc_rcu_dereference(raw->progs); - ret = bpf_prog_array_copy(old_array, prog, NULL, &new_array); + ret = bpf_prog_array_copy(old_array, prog, NULL, 0, &new_array); /* * Do not use bpf_prog_array_delete_safe() as we would end up * with a dummy entry in the array, and the we would free the @@ -217,7 +217,7 @@ void lirc_bpf_run(struct rc_dev *rcdev, u32 sample) raw->bpf_sample = sample; if (raw->progs) - BPF_PROG_RUN_ARRAY(raw->progs, &raw->bpf_sample, BPF_PROG_RUN); + BPF_PROG_RUN_ARRAY(raw->progs, &raw->bpf_sample, bpf_prog_run); } /* diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c index e9e81573f21e..fb52cd175b45 100644 --- a/drivers/net/ppp/ppp_generic.c +++ b/drivers/net/ppp/ppp_generic.c @@ -1744,7 +1744,7 @@ ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) a four-byte PPP header on each packet */ *(u8 *)skb_push(skb, 2) = 1; if (ppp->pass_filter && - BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { + bpf_prog_run(ppp->pass_filter, skb) == 0) { if (ppp->debug & 1) netdev_printk(KERN_DEBUG, ppp->dev, "PPP: outbound frame " @@ -1754,7 +1754,7 @@ ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) } /* if this packet passes the active filter, record the time */ if (!(ppp->active_filter && - BPF_PROG_RUN(ppp->active_filter, skb) == 0)) + bpf_prog_run(ppp->active_filter, skb) == 0)) ppp->last_xmit = jiffies; skb_pull(skb, 2); #else @@ -2468,7 +2468,7 @@ ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) *(u8 *)skb_push(skb, 2) = 0; if (ppp->pass_filter && - BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { + bpf_prog_run(ppp->pass_filter, skb) == 0) { if (ppp->debug & 1) netdev_printk(KERN_DEBUG, ppp->dev, "PPP: inbound frame " @@ -2477,7 +2477,7 @@ ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) return; } if (!(ppp->active_filter && - BPF_PROG_RUN(ppp->active_filter, skb) == 0)) + bpf_prog_run(ppp->active_filter, skb) == 0)) ppp->last_recv = jiffies; __skb_pull(skb, 2); } else diff --git a/drivers/net/team/team_mode_loadbalance.c b/drivers/net/team/team_mode_loadbalance.c index 32aef8ac4a14..b095a4b4957b 100644 --- a/drivers/net/team/team_mode_loadbalance.c +++ b/drivers/net/team/team_mode_loadbalance.c @@ -197,7 +197,7 @@ static unsigned int lb_get_skb_hash(struct lb_priv *lb_priv, fp = rcu_dereference_bh(lb_priv->fp); if (unlikely(!fp)) return 0; - lhash = BPF_PROG_RUN(fp, skb); + lhash = bpf_prog_run(fp, skb); c = (char *) &lhash; return c[0] ^ c[1] ^ c[2] ^ c[3]; } diff --git a/include/linux/bpf.h b/include/linux/bpf.h index c8cc09013210..f4c16f19f83e 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1103,7 +1103,7 @@ u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, /* an array of programs to be executed under rcu_lock. * * Typical usage: - * ret = BPF_PROG_RUN_ARRAY(&bpf_prog_array, ctx, BPF_PROG_RUN); + * ret = BPF_PROG_RUN_ARRAY(&bpf_prog_array, ctx, bpf_prog_run); * * the structure returned by bpf_prog_array_alloc() should be populated * with program pointers and the last pointer must be NULL. @@ -1114,7 +1114,10 @@ u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, */ struct bpf_prog_array_item { struct bpf_prog *prog; - struct bpf_cgroup_storage *cgroup_storage[MAX_BPF_CGROUP_STORAGE_TYPE]; + union { + struct bpf_cgroup_storage *cgroup_storage[MAX_BPF_CGROUP_STORAGE_TYPE]; + u64 bpf_cookie; + }; }; struct bpf_prog_array { @@ -1140,73 +1143,133 @@ int bpf_prog_array_copy_info(struct bpf_prog_array *array, int bpf_prog_array_copy(struct bpf_prog_array *old_array, struct bpf_prog *exclude_prog, struct bpf_prog *include_prog, + u64 bpf_cookie, struct bpf_prog_array **new_array); struct bpf_run_ctx {}; struct bpf_cg_run_ctx { struct bpf_run_ctx run_ctx; - struct bpf_prog_array_item *prog_item; + const struct bpf_prog_array_item *prog_item; +}; + +struct bpf_trace_run_ctx { + struct bpf_run_ctx run_ctx; + u64 bpf_cookie; }; +static inline struct bpf_run_ctx *bpf_set_run_ctx(struct bpf_run_ctx *new_ctx) +{ + struct bpf_run_ctx *old_ctx = NULL; + +#ifdef CONFIG_BPF_SYSCALL + old_ctx = current->bpf_ctx; + current->bpf_ctx = new_ctx; +#endif + return old_ctx; +} + +static inline void bpf_reset_run_ctx(struct bpf_run_ctx *old_ctx) +{ +#ifdef CONFIG_BPF_SYSCALL + current->bpf_ctx = old_ctx; +#endif +} + /* BPF program asks to bypass CAP_NET_BIND_SERVICE in bind. */ #define BPF_RET_BIND_NO_CAP_NET_BIND_SERVICE (1 << 0) /* BPF program asks to set CN on the packet. */ #define BPF_RET_SET_CN (1 << 0) -#define BPF_PROG_RUN_ARRAY_FLAGS(array, ctx, func, ret_flags) \ - ({ \ - struct bpf_prog_array_item *_item; \ - struct bpf_prog *_prog; \ - struct bpf_prog_array *_array; \ - struct bpf_run_ctx *old_run_ctx; \ - struct bpf_cg_run_ctx run_ctx; \ - u32 _ret = 1; \ - u32 func_ret; \ - migrate_disable(); \ - rcu_read_lock(); \ - _array = rcu_dereference(array); \ - _item = &_array->items[0]; \ - old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); \ - while ((_prog = READ_ONCE(_item->prog))) { \ - run_ctx.prog_item = _item; \ - func_ret = func(_prog, ctx); \ - _ret &= (func_ret & 1); \ - *(ret_flags) |= (func_ret >> 1); \ - _item++; \ - } \ - bpf_reset_run_ctx(old_run_ctx); \ - rcu_read_unlock(); \ - migrate_enable(); \ - _ret; \ - }) - -#define __BPF_PROG_RUN_ARRAY(array, ctx, func, check_non_null, set_cg_storage) \ - ({ \ - struct bpf_prog_array_item *_item; \ - struct bpf_prog *_prog; \ - struct bpf_prog_array *_array; \ - struct bpf_run_ctx *old_run_ctx; \ - struct bpf_cg_run_ctx run_ctx; \ - u32 _ret = 1; \ - migrate_disable(); \ - rcu_read_lock(); \ - _array = rcu_dereference(array); \ - if (unlikely(check_non_null && !_array))\ - goto _out; \ - _item = &_array->items[0]; \ - old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);\ - while ((_prog = READ_ONCE(_item->prog))) { \ - run_ctx.prog_item = _item; \ - _ret &= func(_prog, ctx); \ - _item++; \ - } \ - bpf_reset_run_ctx(old_run_ctx); \ -_out: \ - rcu_read_unlock(); \ - migrate_enable(); \ - _ret; \ - }) +typedef u32 (*bpf_prog_run_fn)(const struct bpf_prog *prog, const void *ctx); + +static __always_inline u32 +BPF_PROG_RUN_ARRAY_CG_FLAGS(const struct bpf_prog_array __rcu *array_rcu, + const void *ctx, bpf_prog_run_fn run_prog, + u32 *ret_flags) +{ + const struct bpf_prog_array_item *item; + const struct bpf_prog *prog; + const struct bpf_prog_array *array; + struct bpf_run_ctx *old_run_ctx; + struct bpf_cg_run_ctx run_ctx; + u32 ret = 1; + u32 func_ret; + + migrate_disable(); + rcu_read_lock(); + array = rcu_dereference(array_rcu); + item = &array->items[0]; + old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); + while ((prog = READ_ONCE(item->prog))) { + run_ctx.prog_item = item; + func_ret = run_prog(prog, ctx); + ret &= (func_ret & 1); + *(ret_flags) |= (func_ret >> 1); + item++; + } + bpf_reset_run_ctx(old_run_ctx); + rcu_read_unlock(); + migrate_enable(); + return ret; +} + +static __always_inline u32 +BPF_PROG_RUN_ARRAY_CG(const struct bpf_prog_array __rcu *array_rcu, + const void *ctx, bpf_prog_run_fn run_prog) +{ + const struct bpf_prog_array_item *item; + const struct bpf_prog *prog; + const struct bpf_prog_array *array; + struct bpf_run_ctx *old_run_ctx; + struct bpf_cg_run_ctx run_ctx; + u32 ret = 1; + + migrate_disable(); + rcu_read_lock(); + array = rcu_dereference(array_rcu); + item = &array->items[0]; + old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); + while ((prog = READ_ONCE(item->prog))) { + run_ctx.prog_item = item; + ret &= run_prog(prog, ctx); + item++; + } + bpf_reset_run_ctx(old_run_ctx); + rcu_read_unlock(); + migrate_enable(); + return ret; +} + +static __always_inline u32 +BPF_PROG_RUN_ARRAY(const struct bpf_prog_array __rcu *array_rcu, + const void *ctx, bpf_prog_run_fn run_prog) +{ + const struct bpf_prog_array_item *item; + const struct bpf_prog *prog; + const struct bpf_prog_array *array; + struct bpf_run_ctx *old_run_ctx; + struct bpf_trace_run_ctx run_ctx; + u32 ret = 1; + + migrate_disable(); + rcu_read_lock(); + array = rcu_dereference(array_rcu); + if (unlikely(!array)) + goto out; + old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); + item = &array->items[0]; + while ((prog = READ_ONCE(item->prog))) { + run_ctx.bpf_cookie = item->bpf_cookie; + ret &= run_prog(prog, ctx); + item++; + } + bpf_reset_run_ctx(old_run_ctx); +out: + rcu_read_unlock(); + migrate_enable(); + return ret; +} /* To be used by __cgroup_bpf_run_filter_skb for EGRESS BPF progs * so BPF programs can request cwr for TCP packets. @@ -1235,7 +1298,7 @@ _out: \ u32 _flags = 0; \ bool _cn; \ u32 _ret; \ - _ret = BPF_PROG_RUN_ARRAY_FLAGS(array, ctx, func, &_flags); \ + _ret = BPF_PROG_RUN_ARRAY_CG_FLAGS(array, ctx, func, &_flags); \ _cn = _flags & BPF_RET_SET_CN; \ if (_ret) \ _ret = (_cn ? NET_XMIT_CN : NET_XMIT_SUCCESS); \ @@ -1244,12 +1307,6 @@ _out: \ _ret; \ }) -#define BPF_PROG_RUN_ARRAY(array, ctx, func) \ - __BPF_PROG_RUN_ARRAY(array, ctx, func, false, true) - -#define BPF_PROG_RUN_ARRAY_CHECK(array, ctx, func) \ - __BPF_PROG_RUN_ARRAY(array, ctx, func, true, false) - #ifdef CONFIG_BPF_SYSCALL DECLARE_PER_CPU(int, bpf_prog_active); extern struct mutex bpf_stats_enabled_mutex; @@ -1284,20 +1341,6 @@ static inline void bpf_enable_instrumentation(void) migrate_enable(); } -static inline struct bpf_run_ctx *bpf_set_run_ctx(struct bpf_run_ctx *new_ctx) -{ - struct bpf_run_ctx *old_ctx; - - old_ctx = current->bpf_ctx; - current->bpf_ctx = new_ctx; - return old_ctx; -} - -static inline void bpf_reset_run_ctx(struct bpf_run_ctx *old_ctx) -{ - current->bpf_ctx = old_ctx; -} - extern const struct file_operations bpf_map_fops; extern const struct file_operations bpf_prog_fops; extern const struct file_operations bpf_iter_fops; @@ -2059,9 +2102,6 @@ extern const struct bpf_func_proto bpf_btf_find_by_name_kind_proto; extern const struct bpf_func_proto bpf_sk_setsockopt_proto; extern const struct bpf_func_proto bpf_sk_getsockopt_proto; -const struct bpf_func_proto *bpf_tracing_func_proto( - enum bpf_func_id func_id, const struct bpf_prog *prog); - const struct bpf_func_proto *tracing_prog_func_proto( enum bpf_func_id func_id, const struct bpf_prog *prog); diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h index ae3ac3a2018c..9c81724e4b98 100644 --- a/include/linux/bpf_types.h +++ b/include/linux/bpf_types.h @@ -136,3 +136,6 @@ BPF_LINK_TYPE(BPF_LINK_TYPE_ITER, iter) BPF_LINK_TYPE(BPF_LINK_TYPE_NETNS, netns) BPF_LINK_TYPE(BPF_LINK_TYPE_XDP, xdp) #endif +#ifdef CONFIG_PERF_EVENTS +BPF_LINK_TYPE(BPF_LINK_TYPE_PERF_EVENT, perf) +#endif diff --git a/include/linux/filter.h b/include/linux/filter.h index 1797e8506929..7d248941ecea 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -600,25 +600,38 @@ struct sk_filter { DECLARE_STATIC_KEY_FALSE(bpf_stats_enabled_key); -#define __BPF_PROG_RUN(prog, ctx, dfunc) ({ \ - u32 __ret; \ - cant_migrate(); \ - if (static_branch_unlikely(&bpf_stats_enabled_key)) { \ - struct bpf_prog_stats *__stats; \ - u64 __start = sched_clock(); \ - __ret = dfunc(ctx, (prog)->insnsi, (prog)->bpf_func); \ - __stats = this_cpu_ptr(prog->stats); \ - u64_stats_update_begin(&__stats->syncp); \ - __stats->cnt++; \ - __stats->nsecs += sched_clock() - __start; \ - u64_stats_update_end(&__stats->syncp); \ - } else { \ - __ret = dfunc(ctx, (prog)->insnsi, (prog)->bpf_func); \ - } \ - __ret; }) - -#define BPF_PROG_RUN(prog, ctx) \ - __BPF_PROG_RUN(prog, ctx, bpf_dispatcher_nop_func) +typedef unsigned int (*bpf_dispatcher_fn)(const void *ctx, + const struct bpf_insn *insnsi, + unsigned int (*bpf_func)(const void *, + const struct bpf_insn *)); + +static __always_inline u32 __bpf_prog_run(const struct bpf_prog *prog, + const void *ctx, + bpf_dispatcher_fn dfunc) +{ + u32 ret; + + cant_migrate(); + if (static_branch_unlikely(&bpf_stats_enabled_key)) { + struct bpf_prog_stats *stats; + u64 start = sched_clock(); + + ret = dfunc(ctx, prog->insnsi, prog->bpf_func); + stats = this_cpu_ptr(prog->stats); + u64_stats_update_begin(&stats->syncp); + stats->cnt++; + stats->nsecs += sched_clock() - start; + u64_stats_update_end(&stats->syncp); + } else { + ret = dfunc(ctx, prog->insnsi, prog->bpf_func); + } + return ret; +} + +static __always_inline u32 bpf_prog_run(const struct bpf_prog *prog, const void *ctx) +{ + return __bpf_prog_run(prog, ctx, bpf_dispatcher_nop_func); +} /* * Use in preemptible and therefore migratable context to make sure that @@ -637,7 +650,7 @@ static inline u32 bpf_prog_run_pin_on_cpu(const struct bpf_prog *prog, u32 ret; migrate_disable(); - ret = __BPF_PROG_RUN(prog, ctx, bpf_dispatcher_nop_func); + ret = bpf_prog_run(prog, ctx); migrate_enable(); return ret; } @@ -710,7 +723,7 @@ static inline void bpf_restore_data_end( cb->data_end = saved_data_end; } -static inline u8 *bpf_skb_cb(struct sk_buff *skb) +static inline u8 *bpf_skb_cb(const struct sk_buff *skb) { /* eBPF programs may read/write skb->cb[] area to transfer meta * data between tail calls. Since this also needs to work with @@ -731,8 +744,9 @@ static inline u8 *bpf_skb_cb(struct sk_buff *skb) /* Must be invoked with migration disabled */ static inline u32 __bpf_prog_run_save_cb(const struct bpf_prog *prog, - struct sk_buff *skb) + const void *ctx) { + const struct sk_buff *skb = ctx; u8 *cb_data = bpf_skb_cb(skb); u8 cb_saved[BPF_SKB_CB_LEN]; u32 res; @@ -742,7 +756,7 @@ static inline u32 __bpf_prog_run_save_cb(const struct bpf_prog *prog, memset(cb_data, 0, sizeof(cb_saved)); } - res = BPF_PROG_RUN(prog, skb); + res = bpf_prog_run(prog, skb); if (unlikely(prog->cb_access)) memcpy(cb_data, cb_saved, sizeof(cb_saved)); @@ -787,7 +801,7 @@ static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog, * under local_bh_disable(), which provides the needed RCU protection * for accessing map entries. */ - u32 act = __BPF_PROG_RUN(prog, xdp, BPF_DISPATCHER_FUNC(xdp)); + u32 act = __bpf_prog_run(prog, xdp, BPF_DISPATCHER_FUNC(xdp)); if (static_branch_unlikely(&bpf_master_redirect_enabled_key)) { if (act == XDP_TX && netif_is_bond_slave(xdp->rxq->dev)) @@ -1440,7 +1454,7 @@ static inline bool bpf_sk_lookup_run_v4(struct net *net, int protocol, }; u32 act; - act = BPF_PROG_SK_LOOKUP_RUN_ARRAY(run_array, ctx, BPF_PROG_RUN); + act = BPF_PROG_SK_LOOKUP_RUN_ARRAY(run_array, ctx, bpf_prog_run); if (act == SK_PASS) { selected_sk = ctx.selected_sk; no_reuseport = ctx.no_reuseport; @@ -1478,7 +1492,7 @@ static inline bool bpf_sk_lookup_run_v6(struct net *net, int protocol, }; u32 act; - act = BPF_PROG_SK_LOOKUP_RUN_ARRAY(run_array, ctx, BPF_PROG_RUN); + act = BPF_PROG_SK_LOOKUP_RUN_ARRAY(run_array, ctx, bpf_prog_run); if (act == SK_PASS) { selected_sk = ctx.selected_sk; no_reuseport = ctx.no_reuseport; diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 2d510ad750ed..fe156a8170aa 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -762,6 +762,7 @@ struct perf_event { #ifdef CONFIG_BPF_SYSCALL perf_overflow_handler_t orig_overflow_handler; struct bpf_prog *prog; + u64 bpf_cookie; #endif #ifdef CONFIG_EVENT_TRACING diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index ad413b382a3c..8e0631a4b046 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -675,7 +675,7 @@ trace_trigger_soft_disabled(struct trace_event_file *file) #ifdef CONFIG_BPF_EVENTS unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx); -int perf_event_attach_bpf_prog(struct perf_event *event, struct bpf_prog *prog); +int perf_event_attach_bpf_prog(struct perf_event *event, struct bpf_prog *prog, u64 bpf_cookie); void perf_event_detach_bpf_prog(struct perf_event *event); int perf_event_query_prog_array(struct perf_event *event, void __user *info); int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog); @@ -692,7 +692,7 @@ static inline unsigned int trace_call_bpf(struct trace_event_call *call, void *c } static inline int -perf_event_attach_bpf_prog(struct perf_event *event, struct bpf_prog *prog) +perf_event_attach_bpf_prog(struct perf_event *event, struct bpf_prog *prog, u64 bpf_cookie) { return -EOPNOTSUPP; } @@ -803,6 +803,9 @@ extern void ftrace_profile_free_filter(struct perf_event *event); void perf_trace_buf_update(void *record, u16 type); void *perf_trace_buf_alloc(int size, struct pt_regs **regs, int *rctxp); +int perf_event_set_bpf_prog(struct perf_event *event, struct bpf_prog *prog, u64 bpf_cookie); +void perf_event_free_bpf_prog(struct perf_event *event); + void bpf_trace_run1(struct bpf_prog *prog, u64 arg1); void bpf_trace_run2(struct bpf_prog *prog, u64 arg1, u64 arg2); void bpf_trace_run3(struct bpf_prog *prog, u64 arg1, u64 arg2, diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 2db6925e04f4..c4f7892edb2b 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -993,6 +993,7 @@ enum bpf_attach_type { BPF_SK_SKB_VERDICT, BPF_SK_REUSEPORT_SELECT, BPF_SK_REUSEPORT_SELECT_OR_MIGRATE, + BPF_PERF_EVENT, __MAX_BPF_ATTACH_TYPE }; @@ -1006,6 +1007,7 @@ enum bpf_link_type { BPF_LINK_TYPE_ITER = 4, BPF_LINK_TYPE_NETNS = 5, BPF_LINK_TYPE_XDP = 6, + BPF_LINK_TYPE_PERF_EVENT = 7, MAX_BPF_LINK_TYPE, }; @@ -1446,6 +1448,13 @@ union bpf_attr { __aligned_u64 iter_info; /* extra bpf_iter_link_info */ __u32 iter_info_len; /* iter_info length */ }; + struct { + /* black box user-provided value passed through + * to BPF program at the execution time and + * accessible through bpf_get_attach_cookie() BPF helper + */ + __u64 bpf_cookie; + } perf_event; }; } link_create; @@ -4847,6 +4856,21 @@ union bpf_attr { * Get address of the traced function (for tracing and kprobe programs). * Return * Address of the traced function. + * + * u64 bpf_get_attach_cookie(void *ctx) + * Description + * Get bpf_cookie value provided (optionally) during the program + * attachment. It might be different for each individual + * attachment, even if BPF program itself is the same. + * Expects BPF program context *ctx* as a first argument. + * + * Supported for the following program types: + * - kprobe/uprobe; + * - tracepoint; + * - perf_event. + * Return + * Value specified by user at BPF link creation/attachment time + * or 0, if it was not specified. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -5023,6 +5047,7 @@ union bpf_attr { FN(timer_start), \ FN(timer_cancel), \ FN(get_func_ip), \ + FN(get_attach_cookie), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c index 2e9d47bb40ff..b2ee45064e06 100644 --- a/kernel/bpf/bpf_iter.c +++ b/kernel/bpf/bpf_iter.c @@ -686,7 +686,7 @@ int bpf_iter_run_prog(struct bpf_prog *prog, void *ctx) rcu_read_lock(); migrate_disable(); - ret = BPF_PROG_RUN(prog, ctx); + ret = bpf_prog_run(prog, ctx); migrate_enable(); rcu_read_unlock(); diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index 9f6070369caa..a1dedba4c174 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -1012,8 +1012,8 @@ int __cgroup_bpf_run_filter_skb(struct sock *sk, ret = BPF_PROG_CGROUP_INET_EGRESS_RUN_ARRAY( cgrp->bpf.effective[type], skb, __bpf_prog_run_save_cb); } else { - ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], skb, - __bpf_prog_run_save_cb); + ret = BPF_PROG_RUN_ARRAY_CG(cgrp->bpf.effective[type], skb, + __bpf_prog_run_save_cb); ret = (ret == 1 ? 0 : -EPERM); } bpf_restore_data_end(skb, saved_data_end); @@ -1043,7 +1043,7 @@ int __cgroup_bpf_run_filter_sk(struct sock *sk, struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data); int ret; - ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], sk, BPF_PROG_RUN); + ret = BPF_PROG_RUN_ARRAY_CG(cgrp->bpf.effective[type], sk, bpf_prog_run); return ret == 1 ? 0 : -EPERM; } EXPORT_SYMBOL(__cgroup_bpf_run_filter_sk); @@ -1090,8 +1090,8 @@ int __cgroup_bpf_run_filter_sock_addr(struct sock *sk, } cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data); - ret = BPF_PROG_RUN_ARRAY_FLAGS(cgrp->bpf.effective[type], &ctx, - BPF_PROG_RUN, flags); + ret = BPF_PROG_RUN_ARRAY_CG_FLAGS(cgrp->bpf.effective[type], &ctx, + bpf_prog_run, flags); return ret == 1 ? 0 : -EPERM; } @@ -1120,8 +1120,8 @@ int __cgroup_bpf_run_filter_sock_ops(struct sock *sk, struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data); int ret; - ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], sock_ops, - BPF_PROG_RUN); + ret = BPF_PROG_RUN_ARRAY_CG(cgrp->bpf.effective[type], sock_ops, + bpf_prog_run); return ret == 1 ? 0 : -EPERM; } EXPORT_SYMBOL(__cgroup_bpf_run_filter_sock_ops); @@ -1139,8 +1139,8 @@ int __cgroup_bpf_check_dev_permission(short dev_type, u32 major, u32 minor, rcu_read_lock(); cgrp = task_dfl_cgroup(current); - allow = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], &ctx, - BPF_PROG_RUN); + allow = BPF_PROG_RUN_ARRAY_CG(cgrp->bpf.effective[type], &ctx, + bpf_prog_run); rcu_read_unlock(); return !allow; @@ -1271,7 +1271,7 @@ int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head, rcu_read_lock(); cgrp = task_dfl_cgroup(current); - ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], &ctx, BPF_PROG_RUN); + ret = BPF_PROG_RUN_ARRAY_CG(cgrp->bpf.effective[type], &ctx, bpf_prog_run); rcu_read_unlock(); kfree(ctx.cur_val); @@ -1385,8 +1385,8 @@ int __cgroup_bpf_run_filter_setsockopt(struct sock *sk, int *level, } lock_sock(sk); - ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[BPF_CGROUP_SETSOCKOPT], - &ctx, BPF_PROG_RUN); + ret = BPF_PROG_RUN_ARRAY_CG(cgrp->bpf.effective[BPF_CGROUP_SETSOCKOPT], + &ctx, bpf_prog_run); release_sock(sk); if (!ret) { @@ -1495,8 +1495,8 @@ int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level, } lock_sock(sk); - ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[BPF_CGROUP_GETSOCKOPT], - &ctx, BPF_PROG_RUN); + ret = BPF_PROG_RUN_ARRAY_CG(cgrp->bpf.effective[BPF_CGROUP_GETSOCKOPT], + &ctx, bpf_prog_run); release_sock(sk); if (!ret) { @@ -1556,8 +1556,8 @@ int __cgroup_bpf_run_filter_getsockopt_kern(struct sock *sk, int level, * be called if that data shouldn't be "exported". */ - ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[BPF_CGROUP_GETSOCKOPT], - &ctx, BPF_PROG_RUN); + ret = BPF_PROG_RUN_ARRAY_CG(cgrp->bpf.effective[BPF_CGROUP_GETSOCKOPT], + &ctx, bpf_prog_run); if (!ret) return -EPERM; diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 82af6279992d..91f24c7b38a1 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -1879,7 +1879,7 @@ static void bpf_prog_select_func(struct bpf_prog *fp) * @err: pointer to error variable * * Try to JIT eBPF program, if JIT is not available, use interpreter. - * The BPF program will be executed via BPF_PROG_RUN() macro. + * The BPF program will be executed via bpf_prog_run() function. * * Return: the &fp argument along with &err set to 0 for success or * a negative errno code on failure @@ -2119,13 +2119,13 @@ int bpf_prog_array_update_at(struct bpf_prog_array *array, int index, int bpf_prog_array_copy(struct bpf_prog_array *old_array, struct bpf_prog *exclude_prog, struct bpf_prog *include_prog, + u64 bpf_cookie, struct bpf_prog_array **new_array) { int new_prog_cnt, carry_prog_cnt = 0; - struct bpf_prog_array_item *existing; + struct bpf_prog_array_item *existing, *new; struct bpf_prog_array *array; bool found_exclude = false; - int new_prog_idx = 0; /* Figure out how many existing progs we need to carry over to * the new array. @@ -2162,20 +2162,27 @@ int bpf_prog_array_copy(struct bpf_prog_array *old_array, array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL); if (!array) return -ENOMEM; + new = array->items; /* Fill in the new prog array */ if (carry_prog_cnt) { existing = old_array->items; - for (; existing->prog; existing++) - if (existing->prog != exclude_prog && - existing->prog != &dummy_bpf_prog.prog) { - array->items[new_prog_idx++].prog = - existing->prog; - } + for (; existing->prog; existing++) { + if (existing->prog == exclude_prog || + existing->prog == &dummy_bpf_prog.prog) + continue; + + new->prog = existing->prog; + new->bpf_cookie = existing->bpf_cookie; + new++; + } } - if (include_prog) - array->items[new_prog_idx++].prog = include_prog; - array->items[new_prog_idx].prog = NULL; + if (include_prog) { + new->prog = include_prog; + new->bpf_cookie = bpf_cookie; + new++; + } + new->prog = NULL; *new_array = array; return 0; } diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 9a2068e39d23..7420e1334ab2 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2906,6 +2906,79 @@ static const struct bpf_link_ops bpf_raw_tp_link_lops = { .fill_link_info = bpf_raw_tp_link_fill_link_info, }; +#ifdef CONFIG_PERF_EVENTS +struct bpf_perf_link { + struct bpf_link link; + struct file *perf_file; +}; + +static void bpf_perf_link_release(struct bpf_link *link) +{ + struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); + struct perf_event *event = perf_link->perf_file->private_data; + + perf_event_free_bpf_prog(event); + fput(perf_link->perf_file); +} + +static void bpf_perf_link_dealloc(struct bpf_link *link) +{ + struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); + + kfree(perf_link); +} + +static const struct bpf_link_ops bpf_perf_link_lops = { + .release = bpf_perf_link_release, + .dealloc = bpf_perf_link_dealloc, +}; + +static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) +{ + struct bpf_link_primer link_primer; + struct bpf_perf_link *link; + struct perf_event *event; + struct file *perf_file; + int err; + + if (attr->link_create.flags) + return -EINVAL; + + perf_file = perf_event_get(attr->link_create.target_fd); + if (IS_ERR(perf_file)) + return PTR_ERR(perf_file); + + link = kzalloc(sizeof(*link), GFP_USER); + if (!link) { + err = -ENOMEM; + goto out_put_file; + } + bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog); + link->perf_file = perf_file; + + err = bpf_link_prime(&link->link, &link_primer); + if (err) { + kfree(link); + goto out_put_file; + } + + event = perf_file->private_data; + err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie); + if (err) { + bpf_link_cleanup(&link_primer); + goto out_put_file; + } + /* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */ + bpf_prog_inc(prog); + + return bpf_link_settle(&link_primer); + +out_put_file: + fput(perf_file); + return err; +} +#endif /* CONFIG_PERF_EVENTS */ + #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.prog_fd static int bpf_raw_tracepoint_open(const union bpf_attr *attr) @@ -4147,15 +4220,26 @@ static int link_create(union bpf_attr *attr, bpfptr_t uattr) if (ret) goto out; - if (prog->type == BPF_PROG_TYPE_EXT) { + switch (prog->type) { + case BPF_PROG_TYPE_EXT: ret = tracing_bpf_link_attach(attr, uattr, prog); goto out; - } - - ptype = attach_type_to_prog_type(attr->link_create.attach_type); - if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type) { - ret = -EINVAL; - 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; + 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) { + ret = -EINVAL; + goto out; + } + break; } switch (ptype) { @@ -4180,6 +4264,13 @@ 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 default: ret = -EINVAL; } diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index b2535acfe9db..fe1e857324e6 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -548,7 +548,7 @@ static void notrace inc_misses_counter(struct bpf_prog *prog) u64_stats_update_end(&stats->syncp); } -/* The logic is similar to BPF_PROG_RUN, but with an explicit +/* The logic is similar to bpf_prog_run(), but with an explicit * rcu_read_lock() and migrate_disable() which are required * for the trampoline. The macro is split into * call __bpf_prog_enter diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 5ea2238a6656..f5a0077c9981 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -12383,7 +12383,7 @@ static int jit_subprogs(struct bpf_verifier_env *env) subprog_end = env->subprog_info[i + 1].start; len = subprog_end - subprog_start; - /* BPF_PROG_RUN doesn't call subprogs directly, + /* bpf_prog_run() doesn't call subprogs directly, * hence main prog stats include the runtime of subprogs. * subprogs don't have IDs and not reachable via prog_get_next_id * func[i]->stats will never be accessed and stays NULL diff --git a/kernel/events/core.c b/kernel/events/core.c index 1cb1f9b8392e..2d1e63dd97f2 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -4697,7 +4697,6 @@ errout: } static void perf_event_free_filter(struct perf_event *event); -static void perf_event_free_bpf_prog(struct perf_event *event); static void free_event_rcu(struct rcu_head *head) { @@ -5574,7 +5573,6 @@ static inline int perf_fget_light(int fd, struct fd *p) static int perf_event_set_output(struct perf_event *event, struct perf_event *output_event); static int perf_event_set_filter(struct perf_event *event, void __user *arg); -static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd); static int perf_copy_attr(struct perf_event_attr __user *uattr, struct perf_event_attr *attr); @@ -5637,7 +5635,22 @@ static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned lon return perf_event_set_filter(event, (void __user *)arg); case PERF_EVENT_IOC_SET_BPF: - return perf_event_set_bpf_prog(event, arg); + { + struct bpf_prog *prog; + int err; + + prog = bpf_prog_get(arg); + if (IS_ERR(prog)) + return PTR_ERR(prog); + + err = perf_event_set_bpf_prog(event, prog, 0); + if (err) { + bpf_prog_put(prog); + return err; + } + + return 0; + } case PERF_EVENT_IOC_PAUSE_OUTPUT: { struct perf_buffer *rb; @@ -9913,7 +9926,7 @@ static void bpf_overflow_handler(struct perf_event *event, if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) goto out; rcu_read_lock(); - ret = BPF_PROG_RUN(event->prog, &ctx); + ret = bpf_prog_run(event->prog, &ctx); rcu_read_unlock(); out: __this_cpu_dec(bpf_prog_active); @@ -9923,10 +9936,10 @@ out: event->orig_overflow_handler(event, data, regs); } -static int perf_event_set_bpf_handler(struct perf_event *event, u32 prog_fd) +static int perf_event_set_bpf_handler(struct perf_event *event, + struct bpf_prog *prog, + u64 bpf_cookie) { - struct bpf_prog *prog; - if (event->overflow_handler_context) /* hw breakpoint or kernel counter */ return -EINVAL; @@ -9934,9 +9947,8 @@ static int perf_event_set_bpf_handler(struct perf_event *event, u32 prog_fd) if (event->prog) return -EEXIST; - prog = bpf_prog_get_type(prog_fd, BPF_PROG_TYPE_PERF_EVENT); - if (IS_ERR(prog)) - return PTR_ERR(prog); + if (prog->type != BPF_PROG_TYPE_PERF_EVENT) + return -EINVAL; if (event->attr.precise_ip && prog->call_get_stack && @@ -9952,11 +9964,11 @@ static int perf_event_set_bpf_handler(struct perf_event *event, u32 prog_fd) * attached to perf_sample_data, do not allow attaching BPF * program that calls bpf_get_[stack|stackid]. */ - bpf_prog_put(prog); return -EPROTO; } event->prog = prog; + event->bpf_cookie = bpf_cookie; event->orig_overflow_handler = READ_ONCE(event->overflow_handler); WRITE_ONCE(event->overflow_handler, bpf_overflow_handler); return 0; @@ -9974,7 +9986,9 @@ static void perf_event_free_bpf_handler(struct perf_event *event) bpf_prog_put(prog); } #else -static int perf_event_set_bpf_handler(struct perf_event *event, u32 prog_fd) +static int perf_event_set_bpf_handler(struct perf_event *event, + struct bpf_prog *prog, + u64 bpf_cookie) { return -EOPNOTSUPP; } @@ -10002,14 +10016,13 @@ static inline bool perf_event_is_tracing(struct perf_event *event) return false; } -static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) +int perf_event_set_bpf_prog(struct perf_event *event, struct bpf_prog *prog, + u64 bpf_cookie) { bool is_kprobe, is_tracepoint, is_syscall_tp; - struct bpf_prog *prog; - int ret; if (!perf_event_is_tracing(event)) - return perf_event_set_bpf_handler(event, prog_fd); + return perf_event_set_bpf_handler(event, prog, bpf_cookie); is_kprobe = event->tp_event->flags & TRACE_EVENT_FL_UKPROBE; is_tracepoint = event->tp_event->flags & TRACE_EVENT_FL_TRACEPOINT; @@ -10018,41 +10031,27 @@ static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) /* bpf programs can only be attached to u/kprobe or tracepoint */ return -EINVAL; - prog = bpf_prog_get(prog_fd); - if (IS_ERR(prog)) - return PTR_ERR(prog); - if ((is_kprobe && prog->type != BPF_PROG_TYPE_KPROBE) || (is_tracepoint && prog->type != BPF_PROG_TYPE_TRACEPOINT) || - (is_syscall_tp && prog->type != BPF_PROG_TYPE_TRACEPOINT)) { - /* valid fd, but invalid bpf program type */ - bpf_prog_put(prog); + (is_syscall_tp && prog->type != BPF_PROG_TYPE_TRACEPOINT)) return -EINVAL; - } /* Kprobe override only works for kprobes, not uprobes. */ if (prog->kprobe_override && - !(event->tp_event->flags & TRACE_EVENT_FL_KPROBE)) { - bpf_prog_put(prog); + !(event->tp_event->flags & TRACE_EVENT_FL_KPROBE)) return -EINVAL; - } if (is_tracepoint || is_syscall_tp) { int off = trace_event_get_offsets(event->tp_event); - if (prog->aux->max_ctx_offset > off) { - bpf_prog_put(prog); + if (prog->aux->max_ctx_offset > off) return -EACCES; - } } - ret = perf_event_attach_bpf_prog(event, prog); - if (ret) - bpf_prog_put(prog); - return ret; + return perf_event_attach_bpf_prog(event, prog, bpf_cookie); } -static void perf_event_free_bpf_prog(struct perf_event *event) +void perf_event_free_bpf_prog(struct perf_event *event) { if (!perf_event_is_tracing(event)) { perf_event_free_bpf_handler(event); @@ -10071,12 +10070,13 @@ static void perf_event_free_filter(struct perf_event *event) { } -static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) +int perf_event_set_bpf_prog(struct perf_event *event, struct bpf_prog *prog, + u64 bpf_cookie) { return -ENOENT; } -static void perf_event_free_bpf_prog(struct perf_event *event) +void perf_event_free_bpf_prog(struct perf_event *event) { } #endif /* CONFIG_EVENT_TRACING */ diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 0da94e1d6af9..cbc73c08c4a4 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -124,7 +124,7 @@ unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx) * out of events when it was updated in between this and the * rcu_dereference() which is accepted risk. */ - ret = BPF_PROG_RUN_ARRAY_CHECK(call->prog_array, ctx, BPF_PROG_RUN); + ret = BPF_PROG_RUN_ARRAY(call->prog_array, ctx, bpf_prog_run); out: __this_cpu_dec(bpf_prog_active); @@ -975,7 +975,34 @@ static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { .arg1_type = ARG_PTR_TO_CTX, }; -const struct bpf_func_proto * +BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx) +{ + struct bpf_trace_run_ctx *run_ctx; + + run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); + return run_ctx->bpf_cookie; +} + +static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = { + .func = bpf_get_attach_cookie_trace, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, +}; + +BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx) +{ + return ctx->event->bpf_cookie; +} + +static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = { + .func = bpf_get_attach_cookie_pe, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, +}; + +static const struct bpf_func_proto * bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) { switch (func_id) { @@ -1109,6 +1136,8 @@ kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) #endif case BPF_FUNC_get_func_ip: return &bpf_get_func_ip_proto_kprobe; + case BPF_FUNC_get_attach_cookie: + return &bpf_get_attach_cookie_proto_trace; default: return bpf_tracing_func_proto(func_id, prog); } @@ -1219,6 +1248,8 @@ tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_get_stackid_proto_tp; case BPF_FUNC_get_stack: return &bpf_get_stack_proto_tp; + case BPF_FUNC_get_attach_cookie: + return &bpf_get_attach_cookie_proto_trace; default: return bpf_tracing_func_proto(func_id, prog); } @@ -1326,6 +1357,8 @@ pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_perf_prog_read_value_proto; case BPF_FUNC_read_branch_records: return &bpf_read_branch_records_proto; + case BPF_FUNC_get_attach_cookie: + return &bpf_get_attach_cookie_proto_pe; default: return bpf_tracing_func_proto(func_id, prog); } @@ -1675,7 +1708,8 @@ static DEFINE_MUTEX(bpf_event_mutex); #define BPF_TRACE_MAX_PROGS 64 int perf_event_attach_bpf_prog(struct perf_event *event, - struct bpf_prog *prog) + struct bpf_prog *prog, + u64 bpf_cookie) { struct bpf_prog_array *old_array; struct bpf_prog_array *new_array; @@ -1702,12 +1736,13 @@ int perf_event_attach_bpf_prog(struct perf_event *event, goto unlock; } - ret = bpf_prog_array_copy(old_array, NULL, prog, &new_array); + ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array); if (ret < 0) goto unlock; /* set the new array to event->tp_event and set event->prog */ event->prog = prog; + event->bpf_cookie = bpf_cookie; rcu_assign_pointer(event->tp_event->prog_array, new_array); bpf_prog_array_free(old_array); @@ -1728,7 +1763,7 @@ void perf_event_detach_bpf_prog(struct perf_event *event) goto unlock; old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); - ret = bpf_prog_array_copy(old_array, event->prog, NULL, &new_array); + ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array); if (ret == -ENOENT) goto unlock; if (ret < 0) { @@ -1816,7 +1851,7 @@ void __bpf_trace_run(struct bpf_prog *prog, u64 *args) { cant_sleep(); rcu_read_lock(); - (void) BPF_PROG_RUN(prog, args); + (void) bpf_prog_run(prog, args); rcu_read_unlock(); } diff --git a/lib/test_bpf.c b/lib/test_bpf.c index 77fe6fde56c5..830a18ecffc8 100644 --- a/lib/test_bpf.c +++ b/lib/test_bpf.c @@ -8616,7 +8616,7 @@ static int __run_one(const struct bpf_prog *fp, const void *data, start = ktime_get_ns(); for (i = 0; i < runs; i++) - ret = BPF_PROG_RUN(fp, data); + ret = bpf_prog_run(fp, data); finish = ktime_get_ns(); migrate_enable(); diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index 4b855af267b1..2eb0e55ef54d 100644 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -116,7 +116,7 @@ static int bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat, if (xdp) *retval = bpf_prog_run_xdp(prog, ctx); else - *retval = BPF_PROG_RUN(prog, ctx); + *retval = bpf_prog_run(prog, ctx); } while (bpf_test_timer_continue(&t, repeat, &ret, time)); bpf_reset_run_ctx(old_ctx); bpf_test_timer_leave(&t); @@ -327,7 +327,7 @@ __bpf_prog_test_run_raw_tp(void *data) struct bpf_raw_tp_test_run_info *info = data; rcu_read_lock(); - info->retval = BPF_PROG_RUN(info->prog, info->ctx); + info->retval = bpf_prog_run(info->prog, info->ctx); rcu_read_unlock(); } @@ -989,7 +989,7 @@ int bpf_prog_test_run_sk_lookup(struct bpf_prog *prog, const union bpf_attr *kat bpf_test_timer_enter(&t); do { ctx.selected_sk = NULL; - retval = BPF_PROG_SK_LOOKUP_RUN_ARRAY(progs, ctx, BPF_PROG_RUN); + retval = BPF_PROG_SK_LOOKUP_RUN_ARRAY(progs, ctx, bpf_prog_run); } while (bpf_test_timer_continue(&t, repeat, &ret, &duration)); bpf_test_timer_leave(&t); diff --git a/net/core/filter.c b/net/core/filter.c index 3aca07c44fad..5cf38e8886f1 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -114,7 +114,7 @@ EXPORT_SYMBOL_GPL(copy_bpf_fprog_from_user); * Run the eBPF program and then cut skb->data to correct size returned by * the program. If pkt_len is 0 we toss packet. If skb->len is smaller * than pkt_len we keep whole skb->data. This is the socket level - * wrapper to BPF_PROG_RUN. It returns 0 if the packet should + * wrapper to bpf_prog_run. It returns 0 if the packet should * be accepted or -EPERM if the packet should be tossed. * */ @@ -10115,7 +10115,7 @@ struct sock *bpf_run_sk_reuseport(struct sock_reuseport *reuse, struct sock *sk, enum sk_action action; bpf_init_reuseport_kern(&reuse_kern, reuse, sk, skb, migrating_sk, hash); - action = BPF_PROG_RUN(prog, &reuse_kern); + action = bpf_prog_run(prog, &reuse_kern); if (action == SK_PASS) return reuse_kern.selected_sk; diff --git a/net/core/ptp_classifier.c b/net/core/ptp_classifier.c index e33fde06d528..dd4cf01d1e0a 100644 --- a/net/core/ptp_classifier.c +++ b/net/core/ptp_classifier.c @@ -103,7 +103,7 @@ static struct bpf_prog *ptp_insns __read_mostly; unsigned int ptp_classify_raw(const struct sk_buff *skb) { - return BPF_PROG_RUN(ptp_insns, skb); + return bpf_prog_run(ptp_insns, skb); } EXPORT_SYMBOL_GPL(ptp_classify_raw); diff --git a/net/netfilter/xt_bpf.c b/net/netfilter/xt_bpf.c index 13cf3f9b5938..849ac552a154 100644 --- a/net/netfilter/xt_bpf.c +++ b/net/netfilter/xt_bpf.c @@ -90,7 +90,7 @@ static bool bpf_mt(const struct sk_buff *skb, struct xt_action_param *par) { const struct xt_bpf_info *info = par->matchinfo; - return BPF_PROG_RUN(info->filter, skb); + return bpf_prog_run(info->filter, skb); } static bool bpf_mt_v1(const struct sk_buff *skb, struct xt_action_param *par) diff --git a/net/sched/act_bpf.c b/net/sched/act_bpf.c index 040807aa15b9..5c36013339e1 100644 --- a/net/sched/act_bpf.c +++ b/net/sched/act_bpf.c @@ -47,11 +47,11 @@ static int tcf_bpf_act(struct sk_buff *skb, const struct tc_action *act, if (at_ingress) { __skb_push(skb, skb->mac_len); bpf_compute_data_pointers(skb); - filter_res = BPF_PROG_RUN(filter, skb); + filter_res = bpf_prog_run(filter, skb); __skb_pull(skb, skb->mac_len); } else { bpf_compute_data_pointers(skb); - filter_res = BPF_PROG_RUN(filter, skb); + filter_res = bpf_prog_run(filter, skb); } if (skb_sk_is_prefetched(skb) && filter_res != TC_ACT_OK) skb_orphan(skb); diff --git a/net/sched/cls_bpf.c b/net/sched/cls_bpf.c index 3b472bafdc9d..df19a847829e 100644 --- a/net/sched/cls_bpf.c +++ b/net/sched/cls_bpf.c @@ -96,11 +96,11 @@ static int cls_bpf_classify(struct sk_buff *skb, const struct tcf_proto *tp, /* It is safe to push/pull even if skb_shared() */ __skb_push(skb, skb->mac_len); bpf_compute_data_pointers(skb); - filter_res = BPF_PROG_RUN(prog->filter, skb); + filter_res = bpf_prog_run(prog->filter, skb); __skb_pull(skb, skb->mac_len); } else { bpf_compute_data_pointers(skb); - filter_res = BPF_PROG_RUN(prog->filter, skb); + filter_res = bpf_prog_run(prog->filter, skb); } if (prog->exts_integrated) { diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 2db6925e04f4..c4f7892edb2b 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -993,6 +993,7 @@ enum bpf_attach_type { BPF_SK_SKB_VERDICT, BPF_SK_REUSEPORT_SELECT, BPF_SK_REUSEPORT_SELECT_OR_MIGRATE, + BPF_PERF_EVENT, __MAX_BPF_ATTACH_TYPE }; @@ -1006,6 +1007,7 @@ enum bpf_link_type { BPF_LINK_TYPE_ITER = 4, BPF_LINK_TYPE_NETNS = 5, BPF_LINK_TYPE_XDP = 6, + BPF_LINK_TYPE_PERF_EVENT = 7, MAX_BPF_LINK_TYPE, }; @@ -1446,6 +1448,13 @@ union bpf_attr { __aligned_u64 iter_info; /* extra bpf_iter_link_info */ __u32 iter_info_len; /* iter_info length */ }; + struct { + /* black box user-provided value passed through + * to BPF program at the execution time and + * accessible through bpf_get_attach_cookie() BPF helper + */ + __u64 bpf_cookie; + } perf_event; }; } link_create; @@ -4847,6 +4856,21 @@ union bpf_attr { * Get address of the traced function (for tracing and kprobe programs). * Return * Address of the traced function. + * + * u64 bpf_get_attach_cookie(void *ctx) + * Description + * Get bpf_cookie value provided (optionally) during the program + * attachment. It might be different for each individual + * attachment, even if BPF program itself is the same. + * Expects BPF program context *ctx* as a first argument. + * + * Supported for the following program types: + * - kprobe/uprobe; + * - tracepoint; + * - perf_event. + * Return + * Value specified by user at BPF link creation/attachment time + * or 0, if it was not specified. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -5023,6 +5047,7 @@ union bpf_attr { FN(timer_start), \ FN(timer_cancel), \ FN(get_func_ip), \ + FN(get_attach_cookie), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile index ec14aa725bb0..74c3b73a5fbe 100644 --- a/tools/lib/bpf/Makefile +++ b/tools/lib/bpf/Makefile @@ -4,8 +4,9 @@ RM ?= rm srctree = $(abs_srctree) +VERSION_SCRIPT := libbpf.map LIBBPF_VERSION := $(shell \ - grep -oE '^LIBBPF_([0-9.]+)' libbpf.map | \ + grep -oE '^LIBBPF_([0-9.]+)' $(VERSION_SCRIPT) | \ sort -rV | head -n1 | cut -d'_' -f2) LIBBPF_MAJOR_VERSION := $(firstword $(subst ., ,$(LIBBPF_VERSION))) @@ -110,7 +111,6 @@ SHARED_OBJDIR := $(OUTPUT)sharedobjs/ STATIC_OBJDIR := $(OUTPUT)staticobjs/ BPF_IN_SHARED := $(SHARED_OBJDIR)libbpf-in.o BPF_IN_STATIC := $(STATIC_OBJDIR)libbpf-in.o -VERSION_SCRIPT := libbpf.map BPF_HELPER_DEFS := $(OUTPUT)bpf_helper_defs.h LIB_TARGET := $(addprefix $(OUTPUT),$(LIB_TARGET)) @@ -163,10 +163,10 @@ $(BPF_HELPER_DEFS): $(srctree)/tools/include/uapi/linux/bpf.h $(OUTPUT)libbpf.so: $(OUTPUT)libbpf.so.$(LIBBPF_VERSION) -$(OUTPUT)libbpf.so.$(LIBBPF_VERSION): $(BPF_IN_SHARED) +$(OUTPUT)libbpf.so.$(LIBBPF_VERSION): $(BPF_IN_SHARED) $(VERSION_SCRIPT) $(QUIET_LINK)$(CC) $(LDFLAGS) \ --shared -Wl,-soname,libbpf.so.$(LIBBPF_MAJOR_VERSION) \ - -Wl,--version-script=$(VERSION_SCRIPT) $^ -lelf -lz -o $@ + -Wl,--version-script=$(VERSION_SCRIPT) $< -lelf -lz -o $@ @ln -sf $(@F) $(OUTPUT)libbpf.so @ln -sf $(@F) $(OUTPUT)libbpf.so.$(LIBBPF_MAJOR_VERSION) @@ -181,7 +181,7 @@ $(OUTPUT)libbpf.pc: check: check_abi -check_abi: $(OUTPUT)libbpf.so +check_abi: $(OUTPUT)libbpf.so $(VERSION_SCRIPT) @if [ "$(GLOBAL_SYM_COUNT)" != "$(VERSIONED_SYM_COUNT)" ]; then \ echo "Warning: Num of global symbols in $(BPF_IN_SHARED)" \ "($(GLOBAL_SYM_COUNT)) does NOT match with num of" \ diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 86dcac44f32f..2401fad090c5 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -684,8 +684,13 @@ int bpf_link_create(int prog_fd, int target_fd, iter_info_len = OPTS_GET(opts, iter_info_len, 0); target_btf_id = OPTS_GET(opts, target_btf_id, 0); - if (iter_info_len && target_btf_id) - return libbpf_err(-EINVAL); + /* validate we don't have unexpected combinations of non-zero fields */ + if (iter_info_len || target_btf_id) { + if (iter_info_len && target_btf_id) + return libbpf_err(-EINVAL); + if (!OPTS_ZEROED(opts, target_btf_id)) + return libbpf_err(-EINVAL); + } memset(&attr, 0, sizeof(attr)); attr.link_create.prog_fd = prog_fd; @@ -693,14 +698,27 @@ int bpf_link_create(int prog_fd, int target_fd, attr.link_create.attach_type = attach_type; attr.link_create.flags = OPTS_GET(opts, flags, 0); - if (iter_info_len) { - attr.link_create.iter_info = - ptr_to_u64(OPTS_GET(opts, iter_info, (void *)0)); - attr.link_create.iter_info_len = iter_info_len; - } else if (target_btf_id) { + if (target_btf_id) { attr.link_create.target_btf_id = target_btf_id; + goto proceed; } + switch (attach_type) { + case BPF_TRACE_ITER: + attr.link_create.iter_info = ptr_to_u64(OPTS_GET(opts, iter_info, (void *)0)); + attr.link_create.iter_info_len = iter_info_len; + break; + case BPF_PERF_EVENT: + attr.link_create.perf_event.bpf_cookie = OPTS_GET(opts, perf_event.bpf_cookie, 0); + if (!OPTS_ZEROED(opts, perf_event)) + return libbpf_err(-EINVAL); + break; + default: + if (!OPTS_ZEROED(opts, flags)) + return libbpf_err(-EINVAL); + break; + } +proceed: fd = sys_bpf(BPF_LINK_CREATE, &attr, sizeof(attr)); return libbpf_err_errno(fd); } diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h index 4f758f8f50cd..6fffb3cdf39b 100644 --- a/tools/lib/bpf/bpf.h +++ b/tools/lib/bpf/bpf.h @@ -177,8 +177,14 @@ struct bpf_link_create_opts { union bpf_iter_link_info *iter_info; __u32 iter_info_len; __u32 target_btf_id; + union { + struct { + __u64 bpf_cookie; + } perf_event; + }; + size_t :0; }; -#define bpf_link_create_opts__last_field target_btf_id +#define bpf_link_create_opts__last_field perf_event LIBBPF_API int bpf_link_create(int prog_fd, int target_fd, enum bpf_attach_type attach_type, diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index ff3c0ee79d85..88d8825fc6f6 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -193,6 +193,8 @@ enum kern_feature_id { FEAT_MODULE_BTF, /* BTF_KIND_FLOAT support */ FEAT_BTF_FLOAT, + /* BPF perf link support */ + FEAT_PERF_LINK, __FEAT_CNT, }; @@ -4337,6 +4339,37 @@ static int probe_module_btf(void) return !err; } +static int probe_perf_link(void) +{ + struct bpf_load_program_attr attr; + struct bpf_insn insns[] = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }; + int prog_fd, link_fd, err; + + memset(&attr, 0, sizeof(attr)); + attr.prog_type = BPF_PROG_TYPE_TRACEPOINT; + attr.insns = insns; + attr.insns_cnt = ARRAY_SIZE(insns); + attr.license = "GPL"; + prog_fd = bpf_load_program_xattr(&attr, NULL, 0); + if (prog_fd < 0) + return -errno; + + /* use invalid perf_event FD to get EBADF, if link is supported; + * otherwise EINVAL should be returned + */ + link_fd = bpf_link_create(prog_fd, -1, BPF_PERF_EVENT, NULL); + err = -errno; /* close() can clobber errno */ + + if (link_fd >= 0) + close(link_fd); + close(prog_fd); + + return link_fd < 0 && err == -EBADF; +} + enum kern_feature_result { FEAT_UNKNOWN = 0, FEAT_SUPPORTED = 1, @@ -4387,6 +4420,9 @@ static struct kern_feature_desc { [FEAT_BTF_FLOAT] = { "BTF_KIND_FLOAT support", probe_kern_btf_float, }, + [FEAT_PERF_LINK] = { + "BPF perf link support", probe_perf_link, + }, }; static bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id feat_id) @@ -8810,7 +8846,7 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, struct bpf_link { int (*detach)(struct bpf_link *link); - int (*destroy)(struct bpf_link *link); + void (*dealloc)(struct bpf_link *link); char *pin_path; /* NULL, if not pinned */ int fd; /* hook FD, -1 if not applicable */ bool disconnected; @@ -8849,11 +8885,12 @@ int bpf_link__destroy(struct bpf_link *link) if (!link->disconnected && link->detach) err = link->detach(link); - if (link->destroy) - link->destroy(link); if (link->pin_path) free(link->pin_path); - free(link); + if (link->dealloc) + link->dealloc(link); + else + free(link); return libbpf_err(err); } @@ -8950,23 +8987,42 @@ int bpf_link__unpin(struct bpf_link *link) return 0; } -static int bpf_link__detach_perf_event(struct bpf_link *link) +struct bpf_link_perf { + struct bpf_link link; + int perf_event_fd; +}; + +static int bpf_link_perf_detach(struct bpf_link *link) { - int err; + struct bpf_link_perf *perf_link = container_of(link, struct bpf_link_perf, link); + int err = 0; - err = ioctl(link->fd, PERF_EVENT_IOC_DISABLE, 0); - if (err) + if (ioctl(perf_link->perf_event_fd, PERF_EVENT_IOC_DISABLE, 0) < 0) err = -errno; + if (perf_link->perf_event_fd != link->fd) + close(perf_link->perf_event_fd); close(link->fd); + return libbpf_err(err); } -struct bpf_link *bpf_program__attach_perf_event(struct bpf_program *prog, int pfd) +static void bpf_link_perf_dealloc(struct bpf_link *link) +{ + struct bpf_link_perf *perf_link = container_of(link, struct bpf_link_perf, link); + + free(perf_link); +} + +struct bpf_link *bpf_program__attach_perf_event_opts(struct bpf_program *prog, int pfd, + const struct bpf_perf_event_opts *opts) { char errmsg[STRERR_BUFSIZE]; - struct bpf_link *link; - int prog_fd, err; + struct bpf_link_perf *link; + int prog_fd, link_fd = -1, err; + + if (!OPTS_VALID(opts, bpf_perf_event_opts)) + return libbpf_err_ptr(-EINVAL); if (pfd < 0) { pr_warn("prog '%s': invalid perf event FD %d\n", @@ -8983,27 +9039,59 @@ struct bpf_link *bpf_program__attach_perf_event(struct bpf_program *prog, int pf link = calloc(1, sizeof(*link)); if (!link) return libbpf_err_ptr(-ENOMEM); - link->detach = &bpf_link__detach_perf_event; - link->fd = pfd; + link->link.detach = &bpf_link_perf_detach; + link->link.dealloc = &bpf_link_perf_dealloc; + link->perf_event_fd = pfd; - if (ioctl(pfd, PERF_EVENT_IOC_SET_BPF, prog_fd) < 0) { - err = -errno; - free(link); - pr_warn("prog '%s': failed to attach to pfd %d: %s\n", - prog->name, pfd, libbpf_strerror_r(err, errmsg, sizeof(errmsg))); - if (err == -EPROTO) - pr_warn("prog '%s': try add PERF_SAMPLE_CALLCHAIN to or remove exclude_callchain_[kernel|user] from pfd %d\n", - prog->name, pfd); - return libbpf_err_ptr(err); + if (kernel_supports(prog->obj, FEAT_PERF_LINK)) { + DECLARE_LIBBPF_OPTS(bpf_link_create_opts, link_opts, + .perf_event.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0)); + + link_fd = bpf_link_create(prog_fd, pfd, BPF_PERF_EVENT, &link_opts); + if (link_fd < 0) { + err = -errno; + pr_warn("prog '%s': failed to create BPF link for perf_event FD %d: %d (%s)\n", + prog->name, pfd, + err, libbpf_strerror_r(err, errmsg, sizeof(errmsg))); + goto err_out; + } + link->link.fd = link_fd; + } else { + if (OPTS_GET(opts, bpf_cookie, 0)) { + pr_warn("prog '%s': user context value is not supported\n", prog->name); + err = -EOPNOTSUPP; + goto err_out; + } + + if (ioctl(pfd, PERF_EVENT_IOC_SET_BPF, prog_fd) < 0) { + err = -errno; + pr_warn("prog '%s': failed to attach to perf_event FD %d: %s\n", + prog->name, pfd, libbpf_strerror_r(err, errmsg, sizeof(errmsg))); + if (err == -EPROTO) + pr_warn("prog '%s': try add PERF_SAMPLE_CALLCHAIN to or remove exclude_callchain_[kernel|user] from pfd %d\n", + prog->name, pfd); + goto err_out; + } + link->link.fd = pfd; } if (ioctl(pfd, PERF_EVENT_IOC_ENABLE, 0) < 0) { err = -errno; - free(link); - pr_warn("prog '%s': failed to enable pfd %d: %s\n", + pr_warn("prog '%s': failed to enable perf_event FD %d: %s\n", prog->name, pfd, libbpf_strerror_r(err, errmsg, sizeof(errmsg))); - return libbpf_err_ptr(err); + goto err_out; } - return link; + + return &link->link; +err_out: + if (link_fd >= 0) + close(link_fd); + free(link); + return libbpf_err_ptr(err); +} + +struct bpf_link *bpf_program__attach_perf_event(struct bpf_program *prog, int pfd) +{ + return bpf_program__attach_perf_event_opts(prog, pfd, NULL); } /* @@ -9064,13 +9152,19 @@ static int determine_uprobe_retprobe_bit(void) return parse_uint_from_file(file, "config:%d\n"); } +#define PERF_UPROBE_REF_CTR_OFFSET_BITS 32 +#define PERF_UPROBE_REF_CTR_OFFSET_SHIFT 32 + static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name, - uint64_t offset, int pid) + uint64_t offset, int pid, size_t ref_ctr_off) { struct perf_event_attr attr = {}; char errmsg[STRERR_BUFSIZE]; int type, pfd, err; + if (ref_ctr_off >= (1ULL << PERF_UPROBE_REF_CTR_OFFSET_BITS)) + return -EINVAL; + type = uprobe ? determine_uprobe_perf_type() : determine_kprobe_perf_type(); if (type < 0) { @@ -9093,6 +9187,7 @@ static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name, } attr.size = sizeof(attr); attr.type = type; + attr.config |= (__u64)ref_ctr_off << PERF_UPROBE_REF_CTR_OFFSET_SHIFT; attr.config1 = ptr_to_u64(name); /* kprobe_func or uprobe_path */ attr.config2 = offset; /* kprobe_addr or probe_offset */ @@ -9114,8 +9209,9 @@ static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name, struct bpf_link * bpf_program__attach_kprobe_opts(struct bpf_program *prog, const char *func_name, - struct bpf_kprobe_opts *opts) + const struct bpf_kprobe_opts *opts) { + DECLARE_LIBBPF_OPTS(bpf_perf_event_opts, pe_opts); char errmsg[STRERR_BUFSIZE]; struct bpf_link *link; unsigned long offset; @@ -9127,16 +9223,17 @@ bpf_program__attach_kprobe_opts(struct bpf_program *prog, retprobe = OPTS_GET(opts, retprobe, false); offset = OPTS_GET(opts, offset, 0); + pe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0); pfd = perf_event_open_probe(false /* uprobe */, retprobe, func_name, - offset, -1 /* pid */); + offset, -1 /* pid */, 0 /* ref_ctr_off */); if (pfd < 0) { pr_warn("prog '%s': failed to create %s '%s' perf event: %s\n", prog->name, retprobe ? "kretprobe" : "kprobe", func_name, libbpf_strerror_r(pfd, errmsg, sizeof(errmsg))); return libbpf_err_ptr(pfd); } - link = bpf_program__attach_perf_event(prog, pfd); + link = bpf_program__attach_perf_event_opts(prog, pfd, &pe_opts); err = libbpf_get_error(link); if (err) { close(pfd); @@ -9191,17 +9288,27 @@ static struct bpf_link *attach_kprobe(const struct bpf_sec_def *sec, return link; } -struct bpf_link *bpf_program__attach_uprobe(struct bpf_program *prog, - bool retprobe, pid_t pid, - const char *binary_path, - size_t func_offset) +LIBBPF_API struct bpf_link * +bpf_program__attach_uprobe_opts(struct bpf_program *prog, pid_t pid, + const char *binary_path, size_t func_offset, + const struct bpf_uprobe_opts *opts) { + DECLARE_LIBBPF_OPTS(bpf_perf_event_opts, pe_opts); char errmsg[STRERR_BUFSIZE]; struct bpf_link *link; + size_t ref_ctr_off; int pfd, err; + bool retprobe; - pfd = perf_event_open_probe(true /* uprobe */, retprobe, - binary_path, func_offset, pid); + if (!OPTS_VALID(opts, bpf_uprobe_opts)) + return libbpf_err_ptr(-EINVAL); + + retprobe = OPTS_GET(opts, retprobe, false); + ref_ctr_off = OPTS_GET(opts, ref_ctr_offset, 0); + pe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0); + + pfd = perf_event_open_probe(true /* uprobe */, retprobe, binary_path, + func_offset, pid, ref_ctr_off); if (pfd < 0) { pr_warn("prog '%s': failed to create %s '%s:0x%zx' perf event: %s\n", prog->name, retprobe ? "uretprobe" : "uprobe", @@ -9209,7 +9316,7 @@ struct bpf_link *bpf_program__attach_uprobe(struct bpf_program *prog, libbpf_strerror_r(pfd, errmsg, sizeof(errmsg))); return libbpf_err_ptr(pfd); } - link = bpf_program__attach_perf_event(prog, pfd); + link = bpf_program__attach_perf_event_opts(prog, pfd, &pe_opts); err = libbpf_get_error(link); if (err) { close(pfd); @@ -9222,6 +9329,16 @@ struct bpf_link *bpf_program__attach_uprobe(struct bpf_program *prog, return link; } +struct bpf_link *bpf_program__attach_uprobe(struct bpf_program *prog, + bool retprobe, pid_t pid, + const char *binary_path, + size_t func_offset) +{ + DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, opts, .retprobe = retprobe); + + return bpf_program__attach_uprobe_opts(prog, pid, binary_path, func_offset, &opts); +} + static int determine_tracepoint_id(const char *tp_category, const char *tp_name) { @@ -9272,14 +9389,21 @@ static int perf_event_open_tracepoint(const char *tp_category, return pfd; } -struct bpf_link *bpf_program__attach_tracepoint(struct bpf_program *prog, - const char *tp_category, - const char *tp_name) +struct bpf_link *bpf_program__attach_tracepoint_opts(struct bpf_program *prog, + const char *tp_category, + const char *tp_name, + const struct bpf_tracepoint_opts *opts) { + DECLARE_LIBBPF_OPTS(bpf_perf_event_opts, pe_opts); char errmsg[STRERR_BUFSIZE]; struct bpf_link *link; int pfd, err; + if (!OPTS_VALID(opts, bpf_tracepoint_opts)) + return libbpf_err_ptr(-EINVAL); + + pe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0); + pfd = perf_event_open_tracepoint(tp_category, tp_name); if (pfd < 0) { pr_warn("prog '%s': failed to create tracepoint '%s/%s' perf event: %s\n", @@ -9287,7 +9411,7 @@ struct bpf_link *bpf_program__attach_tracepoint(struct bpf_program *prog, libbpf_strerror_r(pfd, errmsg, sizeof(errmsg))); return libbpf_err_ptr(pfd); } - link = bpf_program__attach_perf_event(prog, pfd); + link = bpf_program__attach_perf_event_opts(prog, pfd, &pe_opts); err = libbpf_get_error(link); if (err) { close(pfd); @@ -9299,6 +9423,13 @@ struct bpf_link *bpf_program__attach_tracepoint(struct bpf_program *prog, return link; } +struct bpf_link *bpf_program__attach_tracepoint(struct bpf_program *prog, + const char *tp_category, + const char *tp_name) +{ + return bpf_program__attach_tracepoint_opts(prog, tp_category, tp_name, NULL); +} + static struct bpf_link *attach_tp(const struct bpf_sec_def *sec, struct bpf_program *prog) { diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 1271d99bb7aa..f177d897c5f7 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -104,17 +104,6 @@ struct bpf_object_open_opts { }; #define bpf_object_open_opts__last_field btf_custom_path -struct bpf_kprobe_opts { - /* size of this struct, for forward/backward compatiblity */ - size_t sz; - /* function's offset to install kprobe to */ - unsigned long offset; - /* kprobe is return probe */ - bool retprobe; - size_t :0; -}; -#define bpf_kprobe_opts__last_field retprobe - LIBBPF_API struct bpf_object *bpf_object__open(const char *path); LIBBPF_API struct bpf_object * bpf_object__open_file(const char *path, const struct bpf_object_open_opts *opts); @@ -255,24 +244,86 @@ LIBBPF_API int bpf_link__destroy(struct bpf_link *link); LIBBPF_API struct bpf_link * bpf_program__attach(struct bpf_program *prog); + +struct bpf_perf_event_opts { + /* size of this struct, for forward/backward compatiblity */ + size_t sz; + /* custom user-provided value fetchable through bpf_get_attach_cookie() */ + __u64 bpf_cookie; +}; +#define bpf_perf_event_opts__last_field bpf_cookie + LIBBPF_API struct bpf_link * bpf_program__attach_perf_event(struct bpf_program *prog, int pfd); + +LIBBPF_API struct bpf_link * +bpf_program__attach_perf_event_opts(struct bpf_program *prog, int pfd, + const struct bpf_perf_event_opts *opts); + +struct bpf_kprobe_opts { + /* size of this struct, for forward/backward compatiblity */ + size_t sz; + /* custom user-provided value fetchable through bpf_get_attach_cookie() */ + __u64 bpf_cookie; + /* function's offset to install kprobe to */ + unsigned long offset; + /* kprobe is return probe */ + bool retprobe; + size_t :0; +}; +#define bpf_kprobe_opts__last_field retprobe + LIBBPF_API struct bpf_link * bpf_program__attach_kprobe(struct bpf_program *prog, bool retprobe, const char *func_name); LIBBPF_API struct bpf_link * bpf_program__attach_kprobe_opts(struct bpf_program *prog, const char *func_name, - struct bpf_kprobe_opts *opts); + const struct bpf_kprobe_opts *opts); + +struct bpf_uprobe_opts { + /* size of this struct, for forward/backward compatiblity */ + size_t sz; + /* offset of kernel reference counted USDT semaphore, added in + * a6ca88b241d5 ("trace_uprobe: support reference counter in fd-based uprobe") + */ + size_t ref_ctr_offset; + /* custom user-provided value fetchable through bpf_get_attach_cookie() */ + __u64 bpf_cookie; + /* uprobe is return probe, invoked at function return time */ + bool retprobe; + size_t :0; +}; +#define bpf_uprobe_opts__last_field retprobe + LIBBPF_API struct bpf_link * bpf_program__attach_uprobe(struct bpf_program *prog, bool retprobe, pid_t pid, const char *binary_path, size_t func_offset); LIBBPF_API struct bpf_link * +bpf_program__attach_uprobe_opts(struct bpf_program *prog, pid_t pid, + const char *binary_path, size_t func_offset, + const struct bpf_uprobe_opts *opts); + +struct bpf_tracepoint_opts { + /* size of this struct, for forward/backward compatiblity */ + size_t sz; + /* custom user-provided value fetchable through bpf_get_attach_cookie() */ + __u64 bpf_cookie; +}; +#define bpf_tracepoint_opts__last_field bpf_cookie + +LIBBPF_API struct bpf_link * bpf_program__attach_tracepoint(struct bpf_program *prog, const char *tp_category, const char *tp_name); LIBBPF_API struct bpf_link * +bpf_program__attach_tracepoint_opts(struct bpf_program *prog, + const char *tp_category, + const char *tp_name, + const struct bpf_tracepoint_opts *opts); + +LIBBPF_API struct bpf_link * bpf_program__attach_raw_tracepoint(struct bpf_program *prog, const char *tp_name); LIBBPF_API struct bpf_link * diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 58e0fb2c482f..bbc53bb25f68 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -374,6 +374,9 @@ LIBBPF_0.5.0 { bpf_map__pin_path; bpf_map_lookup_and_delete_elem_flags; bpf_program__attach_kprobe_opts; + bpf_program__attach_perf_event_opts; + bpf_program__attach_tracepoint_opts; + bpf_program__attach_uprobe_opts; bpf_object__gen_loader; btf__load_from_kernel_by_id; btf__load_from_kernel_by_id_split; diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h index f7b691d5f9eb..533b0211f40a 100644 --- a/tools/lib/bpf/libbpf_internal.h +++ b/tools/lib/bpf/libbpf_internal.h @@ -196,6 +196,17 @@ void *libbpf_add_mem(void **data, size_t *cap_cnt, size_t elem_sz, size_t cur_cnt, size_t max_cnt, size_t add_cnt); int libbpf_ensure_mem(void **data, size_t *cap_cnt, size_t elem_sz, size_t need_cnt); +static inline bool libbpf_is_mem_zeroed(const char *p, ssize_t len) +{ + while (len > 0) { + if (*p) + return false; + p++; + len--; + } + return true; +} + static inline bool libbpf_validate_opts(const char *opts, size_t opts_sz, size_t user_sz, const char *type_name) @@ -204,16 +215,9 @@ static inline bool libbpf_validate_opts(const char *opts, pr_warn("%s size (%zu) is too small\n", type_name, user_sz); return false; } - if (user_sz > opts_sz) { - size_t i; - - for (i = opts_sz; i < user_sz; i++) { - if (opts[i]) { - pr_warn("%s has non-zero extra bytes\n", - type_name); - return false; - } - } + if (!libbpf_is_mem_zeroed(opts + opts_sz, (ssize_t)user_sz - opts_sz)) { + pr_warn("%s has non-zero extra bytes\n", type_name); + return false; } return true; } @@ -233,6 +237,14 @@ static inline bool libbpf_validate_opts(const char *opts, (opts)->field = value; \ } while (0) +#define OPTS_ZEROED(opts, last_nonzero_field) \ +({ \ + ssize_t __off = offsetofend(typeof(*(opts)), last_nonzero_field); \ + !(opts) || libbpf_is_mem_zeroed((const void *)opts + __off, \ + (opts)->sz - __off); \ +}) + + int parse_cpu_mask_str(const char *s, bool **mask, int *mask_sz); int parse_cpu_mask_file(const char *fcpu, bool **mask, int *mask_sz); int libbpf__load_raw_btf(const char *raw_types, size_t types_len, diff --git a/tools/testing/selftests/bpf/prog_tests/attach_probe.c b/tools/testing/selftests/bpf/prog_tests/attach_probe.c index ec11e20d2b92..bf307bb9e446 100644 --- a/tools/testing/selftests/bpf/prog_tests/attach_probe.c +++ b/tools/testing/selftests/bpf/prog_tests/attach_probe.c @@ -2,79 +2,28 @@ #include <test_progs.h> #include "test_attach_probe.skel.h" -#if defined(__powerpc64__) && defined(_CALL_ELF) && _CALL_ELF == 2 - -#define OP_RT_RA_MASK 0xffff0000UL -#define LIS_R2 0x3c400000UL -#define ADDIS_R2_R12 0x3c4c0000UL -#define ADDI_R2_R2 0x38420000UL - -static ssize_t get_offset(ssize_t addr, ssize_t base) -{ - u32 *insn = (u32 *) addr; - - /* - * A PPC64 ABIv2 function may have a local and a global entry - * point. We need to use the local entry point when patching - * functions, so identify and step over the global entry point - * sequence. - * - * The global entry point sequence is always of the form: - * - * addis r2,r12,XXXX - * addi r2,r2,XXXX - * - * A linker optimisation may convert the addis to lis: - * - * lis r2,XXXX - * addi r2,r2,XXXX - */ - if ((((*insn & OP_RT_RA_MASK) == ADDIS_R2_R12) || - ((*insn & OP_RT_RA_MASK) == LIS_R2)) && - ((*(insn + 1) & OP_RT_RA_MASK) == ADDI_R2_R2)) - return (ssize_t)(insn + 2) - base; - else - return addr - base; -} -#else -#define get_offset(addr, base) (addr - base) -#endif - -ssize_t get_base_addr() { - size_t start, offset; - char buf[256]; - FILE *f; - - f = fopen("/proc/self/maps", "r"); - if (!f) - return -errno; - - while (fscanf(f, "%zx-%*x %s %zx %*[^\n]\n", - &start, buf, &offset) == 3) { - if (strcmp(buf, "r-xp") == 0) { - fclose(f); - return start - offset; - } - } - - fclose(f); - return -EINVAL; -} +/* this is how USDT semaphore is actually defined, except volatile modifier */ +volatile unsigned short uprobe_ref_ctr __attribute__((unused)) __attribute((section(".probes"))); void test_attach_probe(void) { + DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts); int duration = 0; struct bpf_link *kprobe_link, *kretprobe_link; struct bpf_link *uprobe_link, *uretprobe_link; struct test_attach_probe* skel; size_t uprobe_offset; - ssize_t base_addr; + ssize_t base_addr, ref_ctr_offset; base_addr = get_base_addr(); if (CHECK(base_addr < 0, "get_base_addr", "failed to find base addr: %zd", base_addr)) return; - uprobe_offset = get_offset((size_t)&get_base_addr, base_addr); + uprobe_offset = get_uprobe_offset(&get_base_addr, base_addr); + + ref_ctr_offset = get_rel_offset((uintptr_t)&uprobe_ref_ctr); + if (!ASSERT_GE(ref_ctr_offset, 0, "ref_ctr_offset")) + return; skel = test_attach_probe__open_and_load(); if (CHECK(!skel, "skel_open", "failed to open skeleton\n")) @@ -96,20 +45,28 @@ void test_attach_probe(void) goto cleanup; skel->links.handle_kretprobe = kretprobe_link; - uprobe_link = bpf_program__attach_uprobe(skel->progs.handle_uprobe, - false /* retprobe */, - 0 /* self pid */, - "/proc/self/exe", - uprobe_offset); + ASSERT_EQ(uprobe_ref_ctr, 0, "uprobe_ref_ctr_before"); + + uprobe_opts.retprobe = false; + uprobe_opts.ref_ctr_offset = ref_ctr_offset; + uprobe_link = bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe, + 0 /* self pid */, + "/proc/self/exe", + uprobe_offset, + &uprobe_opts); if (!ASSERT_OK_PTR(uprobe_link, "attach_uprobe")) goto cleanup; skel->links.handle_uprobe = uprobe_link; - uretprobe_link = bpf_program__attach_uprobe(skel->progs.handle_uretprobe, - true /* retprobe */, - -1 /* any pid */, - "/proc/self/exe", - uprobe_offset); + ASSERT_GT(uprobe_ref_ctr, 0, "uprobe_ref_ctr_after"); + + /* if uprobe uses ref_ctr, uretprobe has to use ref_ctr as well */ + uprobe_opts.retprobe = true; + uprobe_opts.ref_ctr_offset = ref_ctr_offset; + uretprobe_link = bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe, + -1 /* any pid */, + "/proc/self/exe", + uprobe_offset, &uprobe_opts); if (!ASSERT_OK_PTR(uretprobe_link, "attach_uretprobe")) goto cleanup; skel->links.handle_uretprobe = uretprobe_link; @@ -136,4 +93,5 @@ void test_attach_probe(void) cleanup: test_attach_probe__destroy(skel); + ASSERT_EQ(uprobe_ref_ctr, 0, "uprobe_ref_ctr_cleanup"); } diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c b/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c new file mode 100644 index 000000000000..5eea3c3a40fe --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c @@ -0,0 +1,254 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2021 Facebook */ +#define _GNU_SOURCE +#include <pthread.h> +#include <sched.h> +#include <sys/syscall.h> +#include <unistd.h> +#include <test_progs.h> +#include "test_bpf_cookie.skel.h" + +static void kprobe_subtest(struct test_bpf_cookie *skel) +{ + DECLARE_LIBBPF_OPTS(bpf_kprobe_opts, opts); + struct bpf_link *link1 = NULL, *link2 = NULL; + struct bpf_link *retlink1 = NULL, *retlink2 = NULL; + + /* attach two kprobes */ + opts.bpf_cookie = 0x1; + opts.retprobe = false; + link1 = bpf_program__attach_kprobe_opts(skel->progs.handle_kprobe, + SYS_NANOSLEEP_KPROBE_NAME, &opts); + if (!ASSERT_OK_PTR(link1, "link1")) + goto cleanup; + + opts.bpf_cookie = 0x2; + opts.retprobe = false; + link2 = bpf_program__attach_kprobe_opts(skel->progs.handle_kprobe, + SYS_NANOSLEEP_KPROBE_NAME, &opts); + if (!ASSERT_OK_PTR(link2, "link2")) + goto cleanup; + + /* attach two kretprobes */ + opts.bpf_cookie = 0x10; + opts.retprobe = true; + retlink1 = bpf_program__attach_kprobe_opts(skel->progs.handle_kretprobe, + SYS_NANOSLEEP_KPROBE_NAME, &opts); + if (!ASSERT_OK_PTR(retlink1, "retlink1")) + goto cleanup; + + opts.bpf_cookie = 0x20; + opts.retprobe = true; + retlink2 = bpf_program__attach_kprobe_opts(skel->progs.handle_kretprobe, + SYS_NANOSLEEP_KPROBE_NAME, &opts); + if (!ASSERT_OK_PTR(retlink2, "retlink2")) + goto cleanup; + + /* trigger kprobe && kretprobe */ + usleep(1); + + ASSERT_EQ(skel->bss->kprobe_res, 0x1 | 0x2, "kprobe_res"); + ASSERT_EQ(skel->bss->kretprobe_res, 0x10 | 0x20, "kretprobe_res"); + +cleanup: + bpf_link__destroy(link1); + bpf_link__destroy(link2); + bpf_link__destroy(retlink1); + bpf_link__destroy(retlink2); +} + +static void uprobe_subtest(struct test_bpf_cookie *skel) +{ + DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, opts); + struct bpf_link *link1 = NULL, *link2 = NULL; + struct bpf_link *retlink1 = NULL, *retlink2 = NULL; + size_t uprobe_offset; + ssize_t base_addr; + + base_addr = get_base_addr(); + uprobe_offset = get_uprobe_offset(&get_base_addr, base_addr); + + /* attach two uprobes */ + opts.bpf_cookie = 0x100; + opts.retprobe = false; + link1 = bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe, 0 /* self pid */, + "/proc/self/exe", uprobe_offset, &opts); + if (!ASSERT_OK_PTR(link1, "link1")) + goto cleanup; + + opts.bpf_cookie = 0x200; + opts.retprobe = false; + link2 = bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe, -1 /* any pid */, + "/proc/self/exe", uprobe_offset, &opts); + if (!ASSERT_OK_PTR(link2, "link2")) + goto cleanup; + + /* attach two uretprobes */ + opts.bpf_cookie = 0x1000; + opts.retprobe = true; + retlink1 = bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe, -1 /* any pid */, + "/proc/self/exe", uprobe_offset, &opts); + if (!ASSERT_OK_PTR(retlink1, "retlink1")) + goto cleanup; + + opts.bpf_cookie = 0x2000; + opts.retprobe = true; + retlink2 = bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe, 0 /* self pid */, + "/proc/self/exe", uprobe_offset, &opts); + if (!ASSERT_OK_PTR(retlink2, "retlink2")) + goto cleanup; + + /* trigger uprobe && uretprobe */ + get_base_addr(); + + ASSERT_EQ(skel->bss->uprobe_res, 0x100 | 0x200, "uprobe_res"); + ASSERT_EQ(skel->bss->uretprobe_res, 0x1000 | 0x2000, "uretprobe_res"); + +cleanup: + bpf_link__destroy(link1); + bpf_link__destroy(link2); + bpf_link__destroy(retlink1); + bpf_link__destroy(retlink2); +} + +static void tp_subtest(struct test_bpf_cookie *skel) +{ + DECLARE_LIBBPF_OPTS(bpf_tracepoint_opts, opts); + struct bpf_link *link1 = NULL, *link2 = NULL, *link3 = NULL; + + /* attach first tp prog */ + opts.bpf_cookie = 0x10000; + link1 = bpf_program__attach_tracepoint_opts(skel->progs.handle_tp1, + "syscalls", "sys_enter_nanosleep", &opts); + if (!ASSERT_OK_PTR(link1, "link1")) + goto cleanup; + + /* attach second tp prog */ + opts.bpf_cookie = 0x20000; + link2 = bpf_program__attach_tracepoint_opts(skel->progs.handle_tp2, + "syscalls", "sys_enter_nanosleep", &opts); + if (!ASSERT_OK_PTR(link2, "link2")) + goto cleanup; + + /* trigger tracepoints */ + usleep(1); + + ASSERT_EQ(skel->bss->tp_res, 0x10000 | 0x20000, "tp_res1"); + + /* now we detach first prog and will attach third one, which causes + * two internal calls to bpf_prog_array_copy(), shuffling + * bpf_prog_array_items around. We test here that we don't lose track + * of associated bpf_cookies. + */ + bpf_link__destroy(link1); + link1 = NULL; + kern_sync_rcu(); + skel->bss->tp_res = 0; + + /* attach third tp prog */ + opts.bpf_cookie = 0x40000; + link3 = bpf_program__attach_tracepoint_opts(skel->progs.handle_tp3, + "syscalls", "sys_enter_nanosleep", &opts); + if (!ASSERT_OK_PTR(link3, "link3")) + goto cleanup; + + /* trigger tracepoints */ + usleep(1); + + ASSERT_EQ(skel->bss->tp_res, 0x20000 | 0x40000, "tp_res2"); + +cleanup: + bpf_link__destroy(link1); + bpf_link__destroy(link2); + bpf_link__destroy(link3); +} + +static void burn_cpu(void) +{ + volatile int j = 0; + cpu_set_t cpu_set; + int i, err; + + /* generate some branches on cpu 0 */ + CPU_ZERO(&cpu_set); + CPU_SET(0, &cpu_set); + err = pthread_setaffinity_np(pthread_self(), sizeof(cpu_set), &cpu_set); + ASSERT_OK(err, "set_thread_affinity"); + + /* spin the loop for a while (random high number) */ + for (i = 0; i < 1000000; ++i) + ++j; +} + +static void pe_subtest(struct test_bpf_cookie *skel) +{ + DECLARE_LIBBPF_OPTS(bpf_perf_event_opts, opts); + struct bpf_link *link = NULL; + struct perf_event_attr attr; + int pfd = -1; + + /* create perf event */ + memset(&attr, 0, sizeof(attr)); + attr.size = sizeof(attr); + attr.type = PERF_TYPE_SOFTWARE; + attr.config = PERF_COUNT_SW_CPU_CLOCK; + attr.freq = 1; + attr.sample_freq = 4000; + pfd = syscall(__NR_perf_event_open, &attr, -1, 0, -1, PERF_FLAG_FD_CLOEXEC); + if (!ASSERT_GE(pfd, 0, "perf_fd")) + goto cleanup; + + opts.bpf_cookie = 0x100000; + link = bpf_program__attach_perf_event_opts(skel->progs.handle_pe, pfd, &opts); + if (!ASSERT_OK_PTR(link, "link1")) + goto cleanup; + + burn_cpu(); /* trigger BPF prog */ + + ASSERT_EQ(skel->bss->pe_res, 0x100000, "pe_res1"); + + /* prevent bpf_link__destroy() closing pfd itself */ + bpf_link__disconnect(link); + /* close BPF link's FD explicitly */ + close(bpf_link__fd(link)); + /* free up memory used by struct bpf_link */ + bpf_link__destroy(link); + link = NULL; + kern_sync_rcu(); + skel->bss->pe_res = 0; + + opts.bpf_cookie = 0x200000; + link = bpf_program__attach_perf_event_opts(skel->progs.handle_pe, pfd, &opts); + if (!ASSERT_OK_PTR(link, "link2")) + goto cleanup; + + burn_cpu(); /* trigger BPF prog */ + + ASSERT_EQ(skel->bss->pe_res, 0x200000, "pe_res2"); + +cleanup: + close(pfd); + bpf_link__destroy(link); +} + +void test_bpf_cookie(void) +{ + struct test_bpf_cookie *skel; + + skel = test_bpf_cookie__open_and_load(); + if (!ASSERT_OK_PTR(skel, "skel_open")) + return; + + skel->bss->my_tid = syscall(SYS_gettid); + + if (test__start_subtest("kprobe")) + kprobe_subtest(skel); + if (test__start_subtest("uprobe")) + uprobe_subtest(skel); + if (test__start_subtest("tracepoint")) + tp_subtest(skel); + if (test__start_subtest("perf_event")) + pe_subtest(skel); + + test_bpf_cookie__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/prog_tests/perf_link.c b/tools/testing/selftests/bpf/prog_tests/perf_link.c new file mode 100644 index 000000000000..b1abd0c46607 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/perf_link.c @@ -0,0 +1,89 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2021 Facebook */ +#define _GNU_SOURCE +#include <pthread.h> +#include <sched.h> +#include <test_progs.h> +#include "test_perf_link.skel.h" + +static void burn_cpu(void) +{ + volatile int j = 0; + cpu_set_t cpu_set; + int i, err; + + /* generate some branches on cpu 0 */ + CPU_ZERO(&cpu_set); + CPU_SET(0, &cpu_set); + err = pthread_setaffinity_np(pthread_self(), sizeof(cpu_set), &cpu_set); + ASSERT_OK(err, "set_thread_affinity"); + + /* spin the loop for a while (random high number) */ + for (i = 0; i < 1000000; ++i) + ++j; +} + +void test_perf_link(void) +{ + struct test_perf_link *skel = NULL; + struct perf_event_attr attr; + int pfd = -1, link_fd = -1, err; + int run_cnt_before, run_cnt_after; + struct bpf_link_info info; + __u32 info_len = sizeof(info); + + /* create perf event */ + memset(&attr, 0, sizeof(attr)); + attr.size = sizeof(attr); + attr.type = PERF_TYPE_SOFTWARE; + attr.config = PERF_COUNT_SW_CPU_CLOCK; + attr.freq = 1; + attr.sample_freq = 4000; + pfd = syscall(__NR_perf_event_open, &attr, -1, 0, -1, PERF_FLAG_FD_CLOEXEC); + if (!ASSERT_GE(pfd, 0, "perf_fd")) + goto cleanup; + + skel = test_perf_link__open_and_load(); + if (!ASSERT_OK_PTR(skel, "skel_load")) + goto cleanup; + + link_fd = bpf_link_create(bpf_program__fd(skel->progs.handler), pfd, + BPF_PERF_EVENT, NULL); + if (!ASSERT_GE(link_fd, 0, "link_fd")) + goto cleanup; + + memset(&info, 0, sizeof(info)); + err = bpf_obj_get_info_by_fd(link_fd, &info, &info_len); + if (!ASSERT_OK(err, "link_get_info")) + goto cleanup; + + ASSERT_EQ(info.type, BPF_LINK_TYPE_PERF_EVENT, "link_type"); + ASSERT_GT(info.id, 0, "link_id"); + ASSERT_GT(info.prog_id, 0, "link_prog_id"); + + /* ensure we get at least one perf_event prog execution */ + burn_cpu(); + ASSERT_GT(skel->bss->run_cnt, 0, "run_cnt"); + + /* perf_event is still active, but we close link and BPF program + * shouldn't be executed anymore + */ + close(link_fd); + link_fd = -1; + + /* make sure there are no stragglers */ + kern_sync_rcu(); + + run_cnt_before = skel->bss->run_cnt; + burn_cpu(); + run_cnt_after = skel->bss->run_cnt; + + ASSERT_EQ(run_cnt_before, run_cnt_after, "run_cnt_before_after"); + +cleanup: + if (link_fd >= 0) + close(link_fd); + if (pfd >= 0) + close(pfd); + test_perf_link__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/test_bpf_cookie.c b/tools/testing/selftests/bpf/progs/test_bpf_cookie.c new file mode 100644 index 000000000000..2d3a7710e2ce --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_bpf_cookie.c @@ -0,0 +1,85 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2021 Facebook */ + +#include "vmlinux.h" +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> + +int my_tid; + +int kprobe_res; +int kprobe_multi_res; +int kretprobe_res; +int uprobe_res; +int uretprobe_res; +int tp_res; +int pe_res; + +static void update(void *ctx, int *res) +{ + if (my_tid != (u32)bpf_get_current_pid_tgid()) + return; + + *res |= bpf_get_attach_cookie(ctx); +} + +SEC("kprobe/sys_nanosleep") +int handle_kprobe(struct pt_regs *ctx) +{ + update(ctx, &kprobe_res); + return 0; +} + +SEC("kretprobe/sys_nanosleep") +int handle_kretprobe(struct pt_regs *ctx) +{ + update(ctx, &kretprobe_res); + return 0; +} + +SEC("uprobe/trigger_func") +int handle_uprobe(struct pt_regs *ctx) +{ + update(ctx, &uprobe_res); + return 0; +} + +SEC("uretprobe/trigger_func") +int handle_uretprobe(struct pt_regs *ctx) +{ + update(ctx, &uretprobe_res); + return 0; +} + +/* bpf_prog_array, used by kernel internally to keep track of attached BPF + * programs to a given BPF hook (e.g., for tracepoints) doesn't allow the same + * BPF program to be attached multiple times. So have three identical copies + * ready to attach to the same tracepoint. + */ +SEC("tp/syscalls/sys_enter_nanosleep") +int handle_tp1(struct pt_regs *ctx) +{ + update(ctx, &tp_res); + return 0; +} +SEC("tp/syscalls/sys_enter_nanosleep") +int handle_tp2(struct pt_regs *ctx) +{ + update(ctx, &tp_res); + return 0; +} +SEC("tp/syscalls/sys_enter_nanosleep") +int handle_tp3(void *ctx) +{ + update(ctx, &tp_res); + return 1; +} + +SEC("perf_event") +int handle_pe(struct pt_regs *ctx) +{ + update(ctx, &pe_res); + return 0; +} + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/progs/test_perf_link.c b/tools/testing/selftests/bpf/progs/test_perf_link.c new file mode 100644 index 000000000000..c1db9fd98d0c --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_perf_link.c @@ -0,0 +1,16 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2021 Facebook */ +#include "vmlinux.h" +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> + +int run_cnt = 0; + +SEC("perf_event") +int handler(struct pt_regs *ctx) +{ + __sync_fetch_and_add(&run_cnt, 1); + return 0; +} + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c index 1bbd1d9830c8..e7a19b04d4ea 100644 --- a/tools/testing/selftests/bpf/trace_helpers.c +++ b/tools/testing/selftests/bpf/trace_helpers.c @@ -136,3 +136,90 @@ void read_trace_pipe(void) } } } + +#if defined(__powerpc64__) && defined(_CALL_ELF) && _CALL_ELF == 2 + +#define OP_RT_RA_MASK 0xffff0000UL +#define LIS_R2 0x3c400000UL +#define ADDIS_R2_R12 0x3c4c0000UL +#define ADDI_R2_R2 0x38420000UL + +ssize_t get_uprobe_offset(const void *addr, ssize_t base) +{ + u32 *insn = (u32 *)(uintptr_t)addr; + + /* + * A PPC64 ABIv2 function may have a local and a global entry + * point. We need to use the local entry point when patching + * functions, so identify and step over the global entry point + * sequence. + * + * The global entry point sequence is always of the form: + * + * addis r2,r12,XXXX + * addi r2,r2,XXXX + * + * A linker optimisation may convert the addis to lis: + * + * lis r2,XXXX + * addi r2,r2,XXXX + */ + if ((((*insn & OP_RT_RA_MASK) == ADDIS_R2_R12) || + ((*insn & OP_RT_RA_MASK) == LIS_R2)) && + ((*(insn + 1) & OP_RT_RA_MASK) == ADDI_R2_R2)) + return (ssize_t)(insn + 2) - base; + else + return (uintptr_t)addr - base; +} + +#else + +ssize_t get_uprobe_offset(const void *addr, ssize_t base) +{ + return (uintptr_t)addr - base; +} + +#endif + +ssize_t get_base_addr(void) +{ + size_t start, offset; + char buf[256]; + FILE *f; + + f = fopen("/proc/self/maps", "r"); + if (!f) + return -errno; + + while (fscanf(f, "%zx-%*x %s %zx %*[^\n]\n", + &start, buf, &offset) == 3) { + if (strcmp(buf, "r-xp") == 0) { + fclose(f); + return start - offset; + } + } + + fclose(f); + return -EINVAL; +} + +ssize_t get_rel_offset(uintptr_t addr) +{ + size_t start, end, offset; + char buf[256]; + FILE *f; + + f = fopen("/proc/self/maps", "r"); + if (!f) + return -errno; + + while (fscanf(f, "%zx-%zx %s %zx %*[^\n]\n", &start, &end, buf, &offset) == 4) { + if (addr >= start && addr < end) { + fclose(f); + return (size_t)addr - start + offset; + } + } + + fclose(f); + return -EINVAL; +} diff --git a/tools/testing/selftests/bpf/trace_helpers.h b/tools/testing/selftests/bpf/trace_helpers.h index f62fdef9e589..d907b445524d 100644 --- a/tools/testing/selftests/bpf/trace_helpers.h +++ b/tools/testing/selftests/bpf/trace_helpers.h @@ -18,4 +18,8 @@ int kallsyms_find(const char *sym, unsigned long long *addr); void read_trace_pipe(void); +ssize_t get_uprobe_offset(const void *addr, ssize_t base); +ssize_t get_base_addr(void); +ssize_t get_rel_offset(uintptr_t addr); + #endif |