| Message ID | 20230803073420.1558613-4-jolsa@kernel.org (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | BPF |
| Headers | show |
| Series | bpf: Add multi uprobe link | expand |
On 8/3/23 12:33 AM, Jiri Olsa wrote: > Adding new multi uprobe link that allows to attach bpf program > to multiple uprobes. > > Uprobes to attach are specified via new link_create uprobe_multi > union: > > struct { > __aligned_u64 path; > __aligned_u64 offsets; > __aligned_u64 ref_ctr_offsets; > __u32 cnt; > __u32 flags; > } uprobe_multi; > > Uprobes are defined for single binary specified in path and multiple > calling sites specified in offsets array with optional reference > counters specified in ref_ctr_offsets array. All specified arrays > have length of 'cnt'. > > The 'flags' supports single bit for now that marks the uprobe as > return probe. > > Acked-by: Andrii Nakryiko <andrii@kernel.org> > Acked-by: Yafang Shao <laoar.shao@gmail.com> > Signed-off-by: Jiri Olsa <jolsa@kernel.org> > --- > include/linux/trace_events.h | 6 + > include/uapi/linux/bpf.h | 16 +++ > kernel/bpf/syscall.c | 14 +- > kernel/trace/bpf_trace.c | 237 +++++++++++++++++++++++++++++++++ > tools/include/uapi/linux/bpf.h | 16 +++ > 5 files changed, 286 insertions(+), 3 deletions(-) > [...] > + > +static int uprobe_prog_run(struct bpf_uprobe *uprobe, > + unsigned long entry_ip, > + struct pt_regs *regs) > +{ > + struct bpf_uprobe_multi_link *link = uprobe->link; > + struct bpf_uprobe_multi_run_ctx run_ctx = { > + .entry_ip = entry_ip, > + }; > + struct bpf_prog *prog = link->link.prog; > + bool sleepable = prog->aux->sleepable; > + struct bpf_run_ctx *old_run_ctx; > + int err = 0; > + > + might_fault(); Could you explain what you try to protect here with might_fault()? In my opinion, might_fault() is unnecessary here since the calling context is process context and there is no mmap_lock held, so might_fault() won't capture anything. might_fault() is used in iter.c and trampoline.c since their calling context is more complex than here and might_fault() may actually capture issues. > + > + migrate_disable(); > + > + if (sleepable) > + rcu_read_lock_trace(); > + else > + rcu_read_lock(); Looking at trampoline.c and iter.c, typical usage is rcu_read_lock_trace()/rcu_read_lock() migrate_disable() Your above sequenence could be correct too. But it is great if we can keep consistency here. > + > + old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); > + err = bpf_prog_run(link->link.prog, regs); > + bpf_reset_run_ctx(old_run_ctx); > + > + if (sleepable) > + rcu_read_unlock_trace(); > + else > + rcu_read_unlock(); > + > + migrate_enable(); > + return err; > +} > + > +static int > +uprobe_multi_link_handler(struct uprobe_consumer *con, struct pt_regs *regs) > +{ > + struct bpf_uprobe *uprobe; > + > + uprobe = container_of(con, struct bpf_uprobe, consumer); > + return uprobe_prog_run(uprobe, instruction_pointer(regs), regs); > +} > + > +static int > +uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs) > +{ > + struct bpf_uprobe *uprobe; > + > + uprobe = container_of(con, struct bpf_uprobe, consumer); > + return uprobe_prog_run(uprobe, func, regs); > +} > + > +int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) > +{ > + struct bpf_uprobe_multi_link *link = NULL; > + unsigned long __user *uref_ctr_offsets; > + unsigned long *ref_ctr_offsets = NULL; > + struct bpf_link_primer link_primer; > + struct bpf_uprobe *uprobes = NULL; > + unsigned long __user *uoffsets; > + void __user *upath; > + u32 flags, cnt, i; > + struct path path; > + char *name; > + int err; > + > + /* no support for 32bit archs yet */ > + if (sizeof(u64) != sizeof(void *)) > + return -EOPNOTSUPP; > + > + if (prog->expected_attach_type != BPF_TRACE_UPROBE_MULTI) > + return -EINVAL; > + > + flags = attr->link_create.uprobe_multi.flags; > + if (flags & ~BPF_F_UPROBE_MULTI_RETURN) > + return -EINVAL; > + > + /* > + * path, offsets and cnt are mandatory, > + * ref_ctr_offsets is optional > + */ > + upath = u64_to_user_ptr(attr->link_create.uprobe_multi.path); > + uoffsets = u64_to_user_ptr(attr->link_create.uprobe_multi.offsets); > + cnt = attr->link_create.uprobe_multi.cnt; > + > + if (!upath || !uoffsets || !cnt) > + return -EINVAL; > + > + uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets); > + > + name = strndup_user(upath, PATH_MAX); > + if (IS_ERR(name)) { > + err = PTR_ERR(name); > + return err; > + } > + > + err = kern_path(name, LOOKUP_FOLLOW, &path); > + kfree(name); > + if (err) > + return err; > + > + if (!d_is_reg(path.dentry)) { > + err = -EBADF; > + goto error_path_put; > + } > + > + err = -ENOMEM; > + > + link = kzalloc(sizeof(*link), GFP_KERNEL); > + uprobes = kvcalloc(cnt, sizeof(*uprobes), GFP_KERNEL); > + > + if (!uprobes || !link) > + goto error_free; > + > + if (uref_ctr_offsets) { > + ref_ctr_offsets = kvcalloc(cnt, sizeof(*ref_ctr_offsets), GFP_KERNEL); > + if (!ref_ctr_offsets) > + goto error_free; > + } > + > + for (i = 0; i < cnt; i++) { > + if (uref_ctr_offsets && __get_user(ref_ctr_offsets[i], uref_ctr_offsets + i)) { > + err = -EFAULT; > + goto error_free; > + } > + if (__get_user(uprobes[i].offset, uoffsets + i)) { > + err = -EFAULT; > + goto error_free; > + } > + > + uprobes[i].link = link; > + > + if (flags & BPF_F_UPROBE_MULTI_RETURN) > + uprobes[i].consumer.ret_handler = uprobe_multi_link_ret_handler; > + else > + uprobes[i].consumer.handler = uprobe_multi_link_handler; > + } > + > + link->cnt = cnt; > + link->uprobes = uprobes; > + link->path = path; > + > + bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI, > + &bpf_uprobe_multi_link_lops, prog); > + > + err = bpf_link_prime(&link->link, &link_primer); > + if (err) > + goto error_free; > + > + for (i = 0; i < cnt; i++) { > + err = uprobe_register_refctr(d_real_inode(link->path.dentry), > + uprobes[i].offset, > + ref_ctr_offsets ? ref_ctr_offsets[i] : 0, > + &uprobes[i].consumer); > + if (err) { > + bpf_uprobe_unregister(&path, uprobes, i); > + bpf_link_cleanup(&link_primer); > + kvfree(ref_ctr_offsets); Is it possible we may miss some of below 'error_free' cleanups? In my opinion, we should replace kvfree(ref_ctr_offsets); return err; with goto error_free; Could you double check? > + return err; > + } > + } > + > + kvfree(ref_ctr_offsets); > + return bpf_link_settle(&link_primer); > + > +error_free: > + kvfree(ref_ctr_offsets); > + kvfree(uprobes); > + kfree(link); > +error_path_put: > + path_put(&path); > + return err; > +} > +#else /* !CONFIG_UPROBES */ > +int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) > +{ > + return -EOPNOTSUPP; > +} > +#endif /* CONFIG_UPROBES */ [...]
On Fri, Aug 04, 2023 at 02:55:29PM -0700, Yonghong Song wrote: SNIP > > +static int uprobe_prog_run(struct bpf_uprobe *uprobe, > > + unsigned long entry_ip, > > + struct pt_regs *regs) > > +{ > > + struct bpf_uprobe_multi_link *link = uprobe->link; > > + struct bpf_uprobe_multi_run_ctx run_ctx = { > > + .entry_ip = entry_ip, > > + }; > > + struct bpf_prog *prog = link->link.prog; > > + bool sleepable = prog->aux->sleepable; > > + struct bpf_run_ctx *old_run_ctx; > > + int err = 0; > > + > > + might_fault(); > > Could you explain what you try to protect here > with might_fault()? > > In my opinion, might_fault() is unnecessary here > since the calling context is process context and > there is no mmap_lock held, so might_fault() > won't capture anything. > > might_fault() is used in iter.c and trampoline.c > since their calling context is more complex > than here and might_fault() may actually capture > issues. hum, I followed bpf_prog_run_array_sleepable, which is called the same way.. will check > > > + > > + migrate_disable(); > > + > > + if (sleepable) > > + rcu_read_lock_trace(); > > + else > > + rcu_read_lock(); > > Looking at trampoline.c and iter.c, typical > usage is > rcu_read_lock_trace()/rcu_read_lock() > migrate_disable() > > Your above sequenence could be correct too. But it > is great if we can keep consistency here. ok, will switch that SNIP > > + link->cnt = cnt; > > + link->uprobes = uprobes; > > + link->path = path; > > + > > + bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI, > > + &bpf_uprobe_multi_link_lops, prog); > > + > > + err = bpf_link_prime(&link->link, &link_primer); > > + if (err) > > + goto error_free; > > + > > + for (i = 0; i < cnt; i++) { > > + err = uprobe_register_refctr(d_real_inode(link->path.dentry), > > + uprobes[i].offset, > > + ref_ctr_offsets ? ref_ctr_offsets[i] : 0, > > + &uprobes[i].consumer); > > + if (err) { > > + bpf_uprobe_unregister(&path, uprobes, i); > > + bpf_link_cleanup(&link_primer); > > + kvfree(ref_ctr_offsets); > > Is it possible we may miss some of below 'error_free' cleanups? > In my opinion, we should replace > kvfree(ref_ctr_offsets); > return err; > with > goto error_free; > > Could you double check? the problem here is that bpf_link_cleanup calls link's dealloc callback, so it get's released in bpf_uprobe_multi_link_dealloc.. which is missing task release :-\ I think we could init the link only after we create all the uprobes, and have single release function dealloc callback and error path in here thanks, jirka > > > + return err; > > + } > > + } > > + > > + kvfree(ref_ctr_offsets); > > + return bpf_link_settle(&link_primer); > > + > > +error_free: > > + kvfree(ref_ctr_offsets); > > + kvfree(uprobes); > > + kfree(link); > > +error_path_put: > > + path_put(&path); > > + return err; > > +} > > +#else /* !CONFIG_UPROBES */ > > +int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) > > +{ > > + return -EOPNOTSUPP; > > +} > > +#endif /* CONFIG_UPROBES */ > [...]
diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index e66d04dbe56a..5b85cf18c350 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -752,6 +752,7 @@ int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, u32 *fd_type, const char **buf, u64 *probe_offset, u64 *probe_addr); int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog); +int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog); #else static inline unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx) { @@ -798,6 +799,11 @@ bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) { return -EOPNOTSUPP; } +static inline int +bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) +{ + return -EOPNOTSUPP; +} #endif enum { diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 7abb382dc6c1..f112a0b948f3 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -1039,6 +1039,7 @@ enum bpf_attach_type { BPF_NETFILTER, BPF_TCX_INGRESS, BPF_TCX_EGRESS, + BPF_TRACE_UPROBE_MULTI, __MAX_BPF_ATTACH_TYPE }; @@ -1057,6 +1058,7 @@ enum bpf_link_type { BPF_LINK_TYPE_STRUCT_OPS = 9, BPF_LINK_TYPE_NETFILTER = 10, BPF_LINK_TYPE_TCX = 11, + BPF_LINK_TYPE_UPROBE_MULTI = 12, MAX_BPF_LINK_TYPE, }; @@ -1190,6 +1192,13 @@ enum { BPF_F_KPROBE_MULTI_RETURN = (1U << 0) }; +/* link_create.uprobe_multi.flags used in LINK_CREATE command for + * BPF_TRACE_UPROBE_MULTI attach type to create return probe. + */ +enum { + BPF_F_UPROBE_MULTI_RETURN = (1U << 0) +}; + /* link_create.netfilter.flags used in LINK_CREATE command for * BPF_PROG_TYPE_NETFILTER to enable IP packet defragmentation. */ @@ -1626,6 +1635,13 @@ union bpf_attr { }; __u64 expected_revision; } tcx; + struct { + __aligned_u64 path; + __aligned_u64 offsets; + __aligned_u64 ref_ctr_offsets; + __u32 cnt; + __u32 flags; + } uprobe_multi; }; } link_create; diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 7c01186d4078..75c83300339e 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2815,10 +2815,12 @@ static void bpf_link_free_id(int id) /* Clean up bpf_link and corresponding anon_inode file and FD. After * anon_inode is created, bpf_link can't be just kfree()'d due to deferred - * anon_inode's release() call. This helper marksbpf_link as + * anon_inode's release() call. This helper marks bpf_link as * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt * is not decremented, it's the responsibility of a calling code that failed * to complete bpf_link initialization. + * This helper eventually calls link's dealloc callback, but does not call + * link's release callback. */ void bpf_link_cleanup(struct bpf_link_primer *primer) { @@ -3757,8 +3759,12 @@ static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog, if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI && attach_type != BPF_TRACE_KPROBE_MULTI) return -EINVAL; + if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI && + attach_type != BPF_TRACE_UPROBE_MULTI) + return -EINVAL; if (attach_type != BPF_PERF_EVENT && - attach_type != BPF_TRACE_KPROBE_MULTI) + attach_type != BPF_TRACE_KPROBE_MULTI && + attach_type != BPF_TRACE_UPROBE_MULTI) return -EINVAL; return 0; case BPF_PROG_TYPE_SCHED_CLS: @@ -4954,8 +4960,10 @@ static int link_create(union bpf_attr *attr, bpfptr_t uattr) case BPF_PROG_TYPE_KPROBE: if (attr->link_create.attach_type == BPF_PERF_EVENT) ret = bpf_perf_link_attach(attr, prog); - else + else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI) ret = bpf_kprobe_multi_link_attach(attr, prog); + else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI) + ret = bpf_uprobe_multi_link_attach(attr, prog); break; default: ret = -EINVAL; diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 83bde2475ae5..0c67644ccb2e 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -23,6 +23,7 @@ #include <linux/sort.h> #include <linux/key.h> #include <linux/verification.h> +#include <linux/namei.h> #include <net/bpf_sk_storage.h> @@ -2954,3 +2955,239 @@ static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) return 0; } #endif + +#ifdef CONFIG_UPROBES +struct bpf_uprobe_multi_link; + +struct bpf_uprobe { + struct bpf_uprobe_multi_link *link; + loff_t offset; + struct uprobe_consumer consumer; +}; + +struct bpf_uprobe_multi_link { + struct path path; + struct bpf_link link; + u32 cnt; + struct bpf_uprobe *uprobes; +}; + +struct bpf_uprobe_multi_run_ctx { + struct bpf_run_ctx run_ctx; + unsigned long entry_ip; +}; + +static void bpf_uprobe_unregister(struct path *path, struct bpf_uprobe *uprobes, + u32 cnt) +{ + u32 i; + + for (i = 0; i < cnt; i++) { + uprobe_unregister(d_real_inode(path->dentry), uprobes[i].offset, + &uprobes[i].consumer); + } +} + +static void bpf_uprobe_multi_link_release(struct bpf_link *link) +{ + struct bpf_uprobe_multi_link *umulti_link; + + umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); + bpf_uprobe_unregister(&umulti_link->path, umulti_link->uprobes, umulti_link->cnt); +} + +static void bpf_uprobe_multi_link_dealloc(struct bpf_link *link) +{ + struct bpf_uprobe_multi_link *umulti_link; + + umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); + path_put(&umulti_link->path); + kvfree(umulti_link->uprobes); + kfree(umulti_link); +} + +static const struct bpf_link_ops bpf_uprobe_multi_link_lops = { + .release = bpf_uprobe_multi_link_release, + .dealloc = bpf_uprobe_multi_link_dealloc, +}; + +static int uprobe_prog_run(struct bpf_uprobe *uprobe, + unsigned long entry_ip, + struct pt_regs *regs) +{ + struct bpf_uprobe_multi_link *link = uprobe->link; + struct bpf_uprobe_multi_run_ctx run_ctx = { + .entry_ip = entry_ip, + }; + struct bpf_prog *prog = link->link.prog; + bool sleepable = prog->aux->sleepable; + struct bpf_run_ctx *old_run_ctx; + int err = 0; + + might_fault(); + + migrate_disable(); + + if (sleepable) + rcu_read_lock_trace(); + else + rcu_read_lock(); + + old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); + err = bpf_prog_run(link->link.prog, regs); + bpf_reset_run_ctx(old_run_ctx); + + if (sleepable) + rcu_read_unlock_trace(); + else + rcu_read_unlock(); + + migrate_enable(); + return err; +} + +static int +uprobe_multi_link_handler(struct uprobe_consumer *con, struct pt_regs *regs) +{ + struct bpf_uprobe *uprobe; + + uprobe = container_of(con, struct bpf_uprobe, consumer); + return uprobe_prog_run(uprobe, instruction_pointer(regs), regs); +} + +static int +uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs) +{ + struct bpf_uprobe *uprobe; + + uprobe = container_of(con, struct bpf_uprobe, consumer); + return uprobe_prog_run(uprobe, func, regs); +} + +int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) +{ + struct bpf_uprobe_multi_link *link = NULL; + unsigned long __user *uref_ctr_offsets; + unsigned long *ref_ctr_offsets = NULL; + struct bpf_link_primer link_primer; + struct bpf_uprobe *uprobes = NULL; + unsigned long __user *uoffsets; + void __user *upath; + u32 flags, cnt, i; + struct path path; + char *name; + int err; + + /* no support for 32bit archs yet */ + if (sizeof(u64) != sizeof(void *)) + return -EOPNOTSUPP; + + if (prog->expected_attach_type != BPF_TRACE_UPROBE_MULTI) + return -EINVAL; + + flags = attr->link_create.uprobe_multi.flags; + if (flags & ~BPF_F_UPROBE_MULTI_RETURN) + return -EINVAL; + + /* + * path, offsets and cnt are mandatory, + * ref_ctr_offsets is optional + */ + upath = u64_to_user_ptr(attr->link_create.uprobe_multi.path); + uoffsets = u64_to_user_ptr(attr->link_create.uprobe_multi.offsets); + cnt = attr->link_create.uprobe_multi.cnt; + + if (!upath || !uoffsets || !cnt) + return -EINVAL; + + uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets); + + name = strndup_user(upath, PATH_MAX); + if (IS_ERR(name)) { + err = PTR_ERR(name); + return err; + } + + err = kern_path(name, LOOKUP_FOLLOW, &path); + kfree(name); + if (err) + return err; + + if (!d_is_reg(path.dentry)) { + err = -EBADF; + goto error_path_put; + } + + err = -ENOMEM; + + link = kzalloc(sizeof(*link), GFP_KERNEL); + uprobes = kvcalloc(cnt, sizeof(*uprobes), GFP_KERNEL); + + if (!uprobes || !link) + goto error_free; + + if (uref_ctr_offsets) { + ref_ctr_offsets = kvcalloc(cnt, sizeof(*ref_ctr_offsets), GFP_KERNEL); + if (!ref_ctr_offsets) + goto error_free; + } + + for (i = 0; i < cnt; i++) { + if (uref_ctr_offsets && __get_user(ref_ctr_offsets[i], uref_ctr_offsets + i)) { + err = -EFAULT; + goto error_free; + } + if (__get_user(uprobes[i].offset, uoffsets + i)) { + err = -EFAULT; + goto error_free; + } + + uprobes[i].link = link; + + if (flags & BPF_F_UPROBE_MULTI_RETURN) + uprobes[i].consumer.ret_handler = uprobe_multi_link_ret_handler; + else + uprobes[i].consumer.handler = uprobe_multi_link_handler; + } + + link->cnt = cnt; + link->uprobes = uprobes; + link->path = path; + + bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI, + &bpf_uprobe_multi_link_lops, prog); + + err = bpf_link_prime(&link->link, &link_primer); + if (err) + goto error_free; + + for (i = 0; i < cnt; i++) { + err = uprobe_register_refctr(d_real_inode(link->path.dentry), + uprobes[i].offset, + ref_ctr_offsets ? ref_ctr_offsets[i] : 0, + &uprobes[i].consumer); + if (err) { + bpf_uprobe_unregister(&path, uprobes, i); + bpf_link_cleanup(&link_primer); + kvfree(ref_ctr_offsets); + return err; + } + } + + kvfree(ref_ctr_offsets); + return bpf_link_settle(&link_primer); + +error_free: + kvfree(ref_ctr_offsets); + kvfree(uprobes); + kfree(link); +error_path_put: + path_put(&path); + return err; +} +#else /* !CONFIG_UPROBES */ +int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) +{ + return -EOPNOTSUPP; +} +#endif /* CONFIG_UPROBES */ diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 7abb382dc6c1..f112a0b948f3 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -1039,6 +1039,7 @@ enum bpf_attach_type { BPF_NETFILTER, BPF_TCX_INGRESS, BPF_TCX_EGRESS, + BPF_TRACE_UPROBE_MULTI, __MAX_BPF_ATTACH_TYPE }; @@ -1057,6 +1058,7 @@ enum bpf_link_type { BPF_LINK_TYPE_STRUCT_OPS = 9, BPF_LINK_TYPE_NETFILTER = 10, BPF_LINK_TYPE_TCX = 11, + BPF_LINK_TYPE_UPROBE_MULTI = 12, MAX_BPF_LINK_TYPE, }; @@ -1190,6 +1192,13 @@ enum { BPF_F_KPROBE_MULTI_RETURN = (1U << 0) }; +/* link_create.uprobe_multi.flags used in LINK_CREATE command for + * BPF_TRACE_UPROBE_MULTI attach type to create return probe. + */ +enum { + BPF_F_UPROBE_MULTI_RETURN = (1U << 0) +}; + /* link_create.netfilter.flags used in LINK_CREATE command for * BPF_PROG_TYPE_NETFILTER to enable IP packet defragmentation. */ @@ -1626,6 +1635,13 @@ union bpf_attr { }; __u64 expected_revision; } tcx; + struct { + __aligned_u64 path; + __aligned_u64 offsets; + __aligned_u64 ref_ctr_offsets; + __u32 cnt; + __u32 flags; + } uprobe_multi; }; } link_create;
Adding new multi uprobe link that allows to attach bpf program to multiple uprobes. Uprobes to attach are specified via new link_create uprobe_multi union: struct { __aligned_u64 path; __aligned_u64 offsets; __aligned_u64 ref_ctr_offsets; __u32 cnt; __u32 flags; } uprobe_multi; Uprobes are defined for single binary specified in path and multiple calling sites specified in offsets array with optional reference counters specified in ref_ctr_offsets array. All specified arrays have length of 'cnt'. The 'flags' supports single bit for now that marks the uprobe as return probe. Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yafang Shao <laoar.shao@gmail.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> --- include/linux/trace_events.h | 6 + include/uapi/linux/bpf.h | 16 +++ kernel/bpf/syscall.c | 14 +- kernel/trace/bpf_trace.c | 237 +++++++++++++++++++++++++++++++++ tools/include/uapi/linux/bpf.h | 16 +++ 5 files changed, 286 insertions(+), 3 deletions(-)