| Message ID | 20230612151608.99661-11-laoar.shao@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | BPF |
| Headers | show |
| Series | bpf: Support ->fill_link_info for kprobe_multi and perf_event links | expand |
2023-06-12 15:16 UTC+0000 ~ Yafang Shao <laoar.shao@gmail.com> > Enhance bpftool to display comprehensive information about exposed > perf_event links, covering uprobe, kprobe, tracepoint, and generic perf > event. The resulting output will include the following details: > > $ tools/bpf/bpftool/bpftool link show > 3: perf_event prog 14 > event_type software event_config cpu-clock > bpf_cookie 0 > pids perf_event(1379330) > 4: perf_event prog 14 > event_type hw-cache event_config LLC-load-misses > bpf_cookie 0 > pids perf_event(1379330) > 5: perf_event prog 14 > event_type hardware event_config cpu-cycles > bpf_cookie 0 > pids perf_event(1379330) > 6: perf_event prog 20 > retprobe 0 file_name /home/yafang/bpf/uprobe/a.out offset 0x1338 > bpf_cookie 0 > pids uprobe(1379706) > 7: perf_event prog 21 > retprobe 1 file_name /home/yafang/bpf/uprobe/a.out offset 0x1338 > bpf_cookie 0 > pids uprobe(1379706) > 8: perf_event prog 27 > tp_name sched_switch > bpf_cookie 0 > pids tracepoint(1381734) > 10: perf_event prog 43 > retprobe 0 func_name kernel_clone addr ffffffffad0a9660 Could we swap the name and the address, for consistency with the kprobe_multi case? Also do we really need the "_name" suffix in "func_name" and "file_name" for plain output? I don't mind in JSON, but I think the result is a bit long for plain output. > bpf_cookie 0 > pids kprobe(1384186) > 11: perf_event prog 41 > retprobe 1 func_name kernel_clone addr ffffffffad0a9660 > bpf_cookie 0 > pids kprobe(1384186) > > $ tools/bpf/bpftool/bpftool link show -j > [{"id":3,"type":"perf_event","prog_id":14,"event_type":"software","event_config":"cpu-clock","bpf_cookie":0,"pids":[{"pid":1379330,"comm":"perf_event"}]},{"id":4,"type":"perf_event","prog_id":14,"event_type":"hw-cache","event_config":"LLC-load-misses","bpf_cookie":0,"pids":[{"pid":1379330,"comm":"perf_event"}]},{"id":5,"type":"perf_event","prog_id":14,"event_type":"hardware","event_config":"cpu-cycles","bpf_cookie":0,"pids":[{"pid":1379330,"comm":"perf_event"}]},{"id":6,"type":"perf_event","prog_id":20,"retprobe":0,"file_name":"/home/yafang/bpf/uprobe/a.out","offset":4920,"bpf_cookie":0,"pids":[{"pid":1379706,"comm":"uprobe"}]},{"id":7,"type":"perf_event","prog_id":21,"retprobe":1,"file_name":"/home/yafang/bpf/uprobe/a.out","offset":4920,"bpf_cookie":0,"pids":[{"pid":1379706,"comm":"uprobe"}]},{"id":8,"type":"perf_event","prog_id":27,"tp_name":"sched_switch","bpf_cookie":0,"pids":[{"pid":1381734,"comm":"tracepoint"}]},{"id":10,"type":"perf_event","prog_id":43,"retprobe":0,"func_name":"kernel_clone","offset":0,"addr":18446744072317736544,"bpf_cookie":0,"pids":[{"pid":1384186,"comm":"kprobe"}]},{"id":11,"type":"perf_event","prog_id":41,"retprobe":1,"func_name":"kernel_clone","offset":0,"addr":18446744072317736544,"bpf_cookie":0,"pids":[{"pid":1384186,"comm":"kprobe"}]}] > > For generic perf events, the displayed information in bpftool is limited to > the type and configuration, while other attributes such as sample_period, > sample_freq, etc., are not included. > > The kernel function address won't be exposed if it is not permitted by > kptr_restrict. The result as follows when kptr_restrict is 2. > > $ tools/bpf/bpftool/bpftool link show > 3: perf_event prog 14 > event_type software event_config cpu-clock > 4: perf_event prog 14 > event_type hw-cache event_config LLC-load-misses > 5: perf_event prog 14 > event_type hardware event_config cpu-cycles > 6: perf_event prog 20 > retprobe 0 file_name /home/yafang/bpf/uprobe/a.out offset 0x1338 > 7: perf_event prog 21 > retprobe 1 file_name /home/yafang/bpf/uprobe/a.out offset 0x1338 > 8: perf_event prog 27 > tp_name sched_switch > 10: perf_event prog 43 > retprobe 0 func_name kernel_clone > 11: perf_event prog 41 > retprobe 1 func_name kernel_clone > > Signed-off-by: Yafang Shao <laoar.shao@gmail.com> > --- > tools/bpf/bpftool/link.c | 213 +++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 213 insertions(+) > > diff --git a/tools/bpf/bpftool/link.c b/tools/bpf/bpftool/link.c > index 0015582..c16f71d 100644 > --- a/tools/bpf/bpftool/link.c > +++ b/tools/bpf/bpftool/link.c > @@ -15,6 +15,7 @@ > #include "json_writer.h" > #include "main.h" > #include "xlated_dumper.h" > +#include "perf.h" > > static struct hashmap *link_table; > static struct dump_data dd = {}; > @@ -207,6 +208,109 @@ static int cmp_u64(const void *A, const void *B) > jsonw_end_array(json_wtr); > } > > +static void > +show_perf_event_kprobe_json(struct bpf_link_info *info, json_writer_t *wtr) > +{ > + jsonw_uint_field(wtr, "retprobe", info->kprobe.flags & 0x1); "retprobe" should likely be a boolean here too (and below), I don't see them taking any other values than 0 or 1? > + jsonw_string_field(wtr, "func_name", > + u64_to_ptr(info->kprobe.func_name)); > + jsonw_uint_field(wtr, "offset", info->kprobe.offset); > + jsonw_uint_field(wtr, "addr", info->kprobe.addr); > +} > + > +static void > +show_perf_event_uprobe_json(struct bpf_link_info *info, json_writer_t *wtr) > +{ > + jsonw_uint_field(wtr, "retprobe", info->uprobe.flags & 0x1); > + jsonw_string_field(wtr, "file_name", > + u64_to_ptr(info->uprobe.file_name)); > + jsonw_uint_field(wtr, "offset", info->uprobe.offset); > +} > + > +static void > +show_perf_event_tp_json(struct bpf_link_info *info, json_writer_t *wtr) > +{ > + jsonw_string_field(wtr, "tp_name", > + u64_to_ptr(info->tracepoint.tp_name)); > +} > + > +static const char *perf_config_hw_cache_str(__u64 config) The returned "str" is not a "const char *"? Why not simply a "char *" and avoiding the cast when we free() it? > +{ > +#define PERF_HW_CACHE_LEN 128 Let's move the #define to the top of the file, please. > + const char *hw_cache, *result, *op; > + char *str = malloc(PERF_HW_CACHE_LEN); > + > + if (!str) { > + p_err("mem alloc failed"); > + return NULL; > + } > + hw_cache = perf_hw_cache_str(config & 0xff); > + if (hw_cache) > + snprintf(str, PERF_HW_CACHE_LEN, "%s-", hw_cache); > + else > + snprintf(str, PERF_HW_CACHE_LEN, "%lld-", config & 0xff); > + op = perf_hw_cache_op_str((config >> 8) & 0xff); > + if (op) > + snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str), > + "%s-", op); > + else > + snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str), > + "%lld-", (config >> 8) & 0xff); > + result = perf_hw_cache_op_result_str(config >> 16); > + if (result) > + snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str), > + "%s", result); > + else > + snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str), > + "%lld", config >> 16); > + > + return str; > +} > + > +static const char *perf_config_str(__u32 type, __u64 config) > +{ > + const char *perf_config; > + > + switch (type) { > + case PERF_TYPE_HARDWARE: > + perf_config = perf_hw_str(config); > + break; > + case PERF_TYPE_SOFTWARE: > + perf_config = perf_sw_str(config); > + break; > + case PERF_TYPE_HW_CACHE: > + perf_config = perf_config_hw_cache_str(config); > + break; > + default: > + perf_config = NULL; > + break; > + } > + return perf_config; > +} > + > +static void > +show_perf_event_event_json(struct bpf_link_info *info, json_writer_t *wtr) > +{ > + __u64 config = info->perf_event.config; > + __u32 type = info->perf_event.type; > + const char *perf_type, *perf_config; > + > + perf_type = perf_type_str(type); > + if (perf_type) > + jsonw_string_field(wtr, "event_type", perf_type); > + else > + jsonw_uint_field(wtr, "event_type", type); > + > + perf_config = perf_config_str(type, config); > + if (perf_config) > + jsonw_string_field(wtr, "event_config", perf_config); > + else > + jsonw_uint_field(wtr, "event_config", config); > + > + if (type == PERF_TYPE_HW_CACHE && perf_config) > + free((void *)perf_config); > +} > + > static int show_link_close_json(int fd, struct bpf_link_info *info) > { > struct bpf_prog_info prog_info; > @@ -262,6 +366,16 @@ static int show_link_close_json(int fd, struct bpf_link_info *info) > case BPF_LINK_TYPE_KPROBE_MULTI: > show_kprobe_multi_json(info, json_wtr); > break; > + case BPF_LINK_TYPE_PERF_EVENT: > + if (info->perf_link_type == BPF_PERF_LINK_PERF_EVENT) > + show_perf_event_event_json(info, json_wtr); > + else if (info->perf_link_type == BPF_PERF_LINK_TRACEPOINT) > + show_perf_event_tp_json(info, json_wtr); > + else if (info->perf_link_type == BPF_PERF_LINK_KPROBE) > + show_perf_event_kprobe_json(info, json_wtr); > + else if (info->perf_link_type == BPF_PERF_LINK_UPROBE) > + show_perf_event_uprobe_json(info, json_wtr); It would be clearer to me with another switch/case I think (same for plain output), but I don't mind much. > + break; > default: > break; > } > @@ -433,6 +547,71 @@ static void show_kprobe_multi_plain(struct bpf_link_info *info) > } > } > > +static void show_perf_event_kprobe_plain(struct bpf_link_info *info) > +{ > + const char *buf; > + __u32 retprobe; > + > + buf = (const char *)u64_to_ptr(info->kprobe.func_name); > + if (buf[0] == '\0' && !info->kprobe.addr) > + return; > + > + retprobe = info->kprobe.flags & 0x1; > + printf("\n\tretprobe %u func_name %s ", retprobe, buf); > + if (info->kprobe.offset) > + printf("offset %#x ", info->kprobe.offset); > + if (info->kprobe.addr) > + printf("addr %llx ", info->kprobe.addr); > +} > + > +static void show_perf_event_uprobe_plain(struct bpf_link_info *info) > +{ > + const char *buf; > + __u32 retprobe; > + > + buf = (const char *)u64_to_ptr(info->uprobe.file_name); > + if (buf[0] == '\0') > + return; > + > + retprobe = info->uprobe.flags & 0x1; > + printf("\n\tretprobe %u file_name %s ", retprobe, buf); > + if (info->uprobe.offset) > + printf("offset %#x ", info->kprobe.offset); > +} > + > +static void show_perf_event_tp_plain(struct bpf_link_info *info) > +{ > + const char *buf; > + > + buf = (const char *)u64_to_ptr(info->tracepoint.tp_name); > + if (buf[0] == '\0') > + return; > + > + printf("\n\ttp_name %s ", buf); > +} > + > +static void show_perf_event_event_plain(struct bpf_link_info *info) > +{ > + __u64 config = info->perf_event.config; > + __u32 type = info->perf_event.type; > + const char *perf_type, *perf_config; > + > + perf_type = perf_type_str(type); > + if (perf_type) > + printf("\n\tevent_type %s ", perf_type); > + else > + printf("\n\tevent_type %u ", type); > + > + perf_config = perf_config_str(type, config); > + if (perf_config) > + printf("event_config %s ", perf_config); > + else > + printf("event_config %llu ", config); > + > + if (type == PERF_TYPE_HW_CACHE && perf_config) > + free((void *)perf_config); > +} > + > static int show_link_close_plain(int fd, struct bpf_link_info *info) > { > struct bpf_prog_info prog_info; > @@ -481,6 +660,16 @@ static int show_link_close_plain(int fd, struct bpf_link_info *info) > case BPF_LINK_TYPE_KPROBE_MULTI: > show_kprobe_multi_plain(info); > break; > + case BPF_LINK_TYPE_PERF_EVENT: > + if (info->perf_link_type == BPF_PERF_LINK_PERF_EVENT) > + show_perf_event_event_plain(info); > + else if (info->perf_link_type == BPF_PERF_LINK_TRACEPOINT) > + show_perf_event_tp_plain(info); > + else if (info->perf_link_type == BPF_PERF_LINK_KPROBE) > + show_perf_event_kprobe_plain(info); > + else if (info->perf_link_type == BPF_PERF_LINK_UPROBE) > + show_perf_event_uprobe_plain(info); > + break; > default: > break; > } > @@ -508,6 +697,7 @@ static int do_show_link(int fd) > int err; > > memset(&info, 0, sizeof(info)); > + buf[0] = '\0'; > again: > err = bpf_link_get_info_by_fd(fd, &info, &len); > if (err) { > @@ -542,7 +732,30 @@ static int do_show_link(int fd) > goto again; > } > } > + if (info.type == BPF_LINK_TYPE_PERF_EVENT) { > + if (info.perf_link_type == BPF_PERF_LINK_PERF_EVENT) > + goto out; > + if (info.perf_link_type == BPF_PERF_LINK_TRACEPOINT && > + !info.tracepoint.tp_name) { > + info.tracepoint.tp_name = (unsigned long)&buf; > + info.tracepoint.name_len = sizeof(buf); > + goto again; > + } > + if (info.perf_link_type == BPF_PERF_LINK_KPROBE && > + !info.kprobe.func_name) { > + info.kprobe.func_name = (unsigned long)&buf; > + info.kprobe.name_len = sizeof(buf); > + goto again; > + } > + if (info.perf_link_type == BPF_PERF_LINK_UPROBE && > + !info.uprobe.file_name) { > + info.uprobe.file_name = (unsigned long)&buf; > + info.uprobe.name_len = sizeof(buf); Maybe increase the size of buf to accommodate for long paths? > + goto again; > + } > + } > > +out: > if (json_output) > show_link_close_json(fd, &info); > else Thanks for this work!
On Tue, Jun 13, 2023 at 9:42 PM Quentin Monnet <quentin@isovalent.com> wrote: > > 2023-06-12 15:16 UTC+0000 ~ Yafang Shao <laoar.shao@gmail.com> > > Enhance bpftool to display comprehensive information about exposed > > perf_event links, covering uprobe, kprobe, tracepoint, and generic perf > > event. The resulting output will include the following details: > > > > $ tools/bpf/bpftool/bpftool link show > > 3: perf_event prog 14 > > event_type software event_config cpu-clock > > bpf_cookie 0 > > pids perf_event(1379330) > > 4: perf_event prog 14 > > event_type hw-cache event_config LLC-load-misses > > bpf_cookie 0 > > pids perf_event(1379330) > > 5: perf_event prog 14 > > event_type hardware event_config cpu-cycles > > bpf_cookie 0 > > pids perf_event(1379330) > > 6: perf_event prog 20 > > retprobe 0 file_name /home/yafang/bpf/uprobe/a.out offset 0x1338 > > bpf_cookie 0 > > pids uprobe(1379706) > > 7: perf_event prog 21 > > retprobe 1 file_name /home/yafang/bpf/uprobe/a.out offset 0x1338 > > bpf_cookie 0 > > pids uprobe(1379706) > > 8: perf_event prog 27 > > tp_name sched_switch > > bpf_cookie 0 > > pids tracepoint(1381734) > > 10: perf_event prog 43 > > retprobe 0 func_name kernel_clone addr ffffffffad0a9660 > > Could we swap the name and the address, for consistency with the > kprobe_multi case? Agree. Will change it. > > Also do we really need the "_name" suffix in "func_name" and "file_name" > for plain output? I don't mind in JSON, but I think the result is a bit > long for plain output. They are really a bit long. Will remove the "_name" suffix. > > > bpf_cookie 0 > > pids kprobe(1384186) > > 11: perf_event prog 41 > > retprobe 1 func_name kernel_clone addr ffffffffad0a9660 > > bpf_cookie 0 > > pids kprobe(1384186) > > > > $ tools/bpf/bpftool/bpftool link show -j > > [{"id":3,"type":"perf_event","prog_id":14,"event_type":"software","event_config":"cpu-clock","bpf_cookie":0,"pids":[{"pid":1379330,"comm":"perf_event"}]},{"id":4,"type":"perf_event","prog_id":14,"event_type":"hw-cache","event_config":"LLC-load-misses","bpf_cookie":0,"pids":[{"pid":1379330,"comm":"perf_event"}]},{"id":5,"type":"perf_event","prog_id":14,"event_type":"hardware","event_config":"cpu-cycles","bpf_cookie":0,"pids":[{"pid":1379330,"comm":"perf_event"}]},{"id":6,"type":"perf_event","prog_id":20,"retprobe":0,"file_name":"/home/yafang/bpf/uprobe/a.out","offset":4920,"bpf_cookie":0,"pids":[{"pid":1379706,"comm":"uprobe"}]},{"id":7,"type":"perf_event","prog_id":21,"retprobe":1,"file_name":"/home/yafang/bpf/uprobe/a.out","offset":4920,"bpf_cookie":0,"pids":[{"pid":1379706,"comm":"uprobe"}]},{"id":8,"type":"perf_event","prog_id":27,"tp_name":"sched_switch","bpf_cookie":0,"pids":[{"pid":1381734,"comm":"tracepoint"}]},{"id":10,"type":"perf_event","prog_id":43,"retprobe":0,"func_name":"kernel_clone","offset":0,"addr":18446744072317736544,"bpf_cookie":0,"pids":[{"pid":1384186,"comm":"kprobe"}]},{"id":11,"type":"perf_event","prog_id":41,"retprobe":1,"func_name":"kernel_clone","offset":0,"addr":18446744072317736544,"bpf_cookie":0,"pids":[{"pid":1384186,"comm":"kprobe"}]}] > > > > For generic perf events, the displayed information in bpftool is limited to > > the type and configuration, while other attributes such as sample_period, > > sample_freq, etc., are not included. > > > > The kernel function address won't be exposed if it is not permitted by > > kptr_restrict. The result as follows when kptr_restrict is 2. > > > > $ tools/bpf/bpftool/bpftool link show > > 3: perf_event prog 14 > > event_type software event_config cpu-clock > > 4: perf_event prog 14 > > event_type hw-cache event_config LLC-load-misses > > 5: perf_event prog 14 > > event_type hardware event_config cpu-cycles > > 6: perf_event prog 20 > > retprobe 0 file_name /home/yafang/bpf/uprobe/a.out offset 0x1338 > > 7: perf_event prog 21 > > retprobe 1 file_name /home/yafang/bpf/uprobe/a.out offset 0x1338 > > 8: perf_event prog 27 > > tp_name sched_switch > > 10: perf_event prog 43 > > retprobe 0 func_name kernel_clone > > 11: perf_event prog 41 > > retprobe 1 func_name kernel_clone > > > > Signed-off-by: Yafang Shao <laoar.shao@gmail.com> > > --- > > tools/bpf/bpftool/link.c | 213 +++++++++++++++++++++++++++++++++++++++++++++++ > > 1 file changed, 213 insertions(+) > > > > diff --git a/tools/bpf/bpftool/link.c b/tools/bpf/bpftool/link.c > > index 0015582..c16f71d 100644 > > --- a/tools/bpf/bpftool/link.c > > +++ b/tools/bpf/bpftool/link.c > > @@ -15,6 +15,7 @@ > > #include "json_writer.h" > > #include "main.h" > > #include "xlated_dumper.h" > > +#include "perf.h" > > > > static struct hashmap *link_table; > > static struct dump_data dd = {}; > > @@ -207,6 +208,109 @@ static int cmp_u64(const void *A, const void *B) > > jsonw_end_array(json_wtr); > > } > > > > +static void > > +show_perf_event_kprobe_json(struct bpf_link_info *info, json_writer_t *wtr) > > +{ > > + jsonw_uint_field(wtr, "retprobe", info->kprobe.flags & 0x1); > > "retprobe" should likely be a boolean here too (and below), I don't see > them taking any other values than 0 or 1? Right. Should use boolean instead. > > > + jsonw_string_field(wtr, "func_name", > > + u64_to_ptr(info->kprobe.func_name)); > > + jsonw_uint_field(wtr, "offset", info->kprobe.offset); > > + jsonw_uint_field(wtr, "addr", info->kprobe.addr); > > +} > > + > > +static void > > +show_perf_event_uprobe_json(struct bpf_link_info *info, json_writer_t *wtr) > > +{ > > + jsonw_uint_field(wtr, "retprobe", info->uprobe.flags & 0x1); > > + jsonw_string_field(wtr, "file_name", > > + u64_to_ptr(info->uprobe.file_name)); > > + jsonw_uint_field(wtr, "offset", info->uprobe.offset); > > +} > > + > > +static void > > +show_perf_event_tp_json(struct bpf_link_info *info, json_writer_t *wtr) > > +{ > > + jsonw_string_field(wtr, "tp_name", > > + u64_to_ptr(info->tracepoint.tp_name)); > > +} > > + > > +static const char *perf_config_hw_cache_str(__u64 config) > > The returned "str" is not a "const char *"? Why not simply a "char *" > and avoiding the cast when we free() it? Good point. Will change it. > > > +{ > > +#define PERF_HW_CACHE_LEN 128 > > Let's move the #define to the top of the file, please. Agree. > > > + const char *hw_cache, *result, *op; > > + char *str = malloc(PERF_HW_CACHE_LEN); > > + > > + if (!str) { > > + p_err("mem alloc failed"); > > + return NULL; > > + } > > + hw_cache = perf_hw_cache_str(config & 0xff); > > + if (hw_cache) > > + snprintf(str, PERF_HW_CACHE_LEN, "%s-", hw_cache); > > + else > > + snprintf(str, PERF_HW_CACHE_LEN, "%lld-", config & 0xff); > > + op = perf_hw_cache_op_str((config >> 8) & 0xff); > > + if (op) > > + snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str), > > + "%s-", op); > > + else > > + snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str), > > + "%lld-", (config >> 8) & 0xff); > > + result = perf_hw_cache_op_result_str(config >> 16); > > + if (result) > > + snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str), > > + "%s", result); > > + else > > + snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str), > > + "%lld", config >> 16); > > + > > + return str; > > +} > > + > > +static const char *perf_config_str(__u32 type, __u64 config) > > +{ > > + const char *perf_config; > > + > > + switch (type) { > > + case PERF_TYPE_HARDWARE: > > + perf_config = perf_hw_str(config); > > + break; > > + case PERF_TYPE_SOFTWARE: > > + perf_config = perf_sw_str(config); > > + break; > > + case PERF_TYPE_HW_CACHE: > > + perf_config = perf_config_hw_cache_str(config); > > + break; > > + default: > > + perf_config = NULL; > > + break; > > + } > > + return perf_config; > > +} > > + > > +static void > > +show_perf_event_event_json(struct bpf_link_info *info, json_writer_t *wtr) > > +{ > > + __u64 config = info->perf_event.config; > > + __u32 type = info->perf_event.type; > > + const char *perf_type, *perf_config; > > + > > + perf_type = perf_type_str(type); > > + if (perf_type) > > + jsonw_string_field(wtr, "event_type", perf_type); > > + else > > + jsonw_uint_field(wtr, "event_type", type); > > + > > + perf_config = perf_config_str(type, config); > > + if (perf_config) > > + jsonw_string_field(wtr, "event_config", perf_config); > > + else > > + jsonw_uint_field(wtr, "event_config", config); > > + > > + if (type == PERF_TYPE_HW_CACHE && perf_config) > > + free((void *)perf_config); > > +} > > + > > static int show_link_close_json(int fd, struct bpf_link_info *info) > > { > > struct bpf_prog_info prog_info; > > @@ -262,6 +366,16 @@ static int show_link_close_json(int fd, struct bpf_link_info *info) > > case BPF_LINK_TYPE_KPROBE_MULTI: > > show_kprobe_multi_json(info, json_wtr); > > break; > > + case BPF_LINK_TYPE_PERF_EVENT: > > + if (info->perf_link_type == BPF_PERF_LINK_PERF_EVENT) > > + show_perf_event_event_json(info, json_wtr); > > + else if (info->perf_link_type == BPF_PERF_LINK_TRACEPOINT) > > + show_perf_event_tp_json(info, json_wtr); > > + else if (info->perf_link_type == BPF_PERF_LINK_KPROBE) > > + show_perf_event_kprobe_json(info, json_wtr); > > + else if (info->perf_link_type == BPF_PERF_LINK_UPROBE) > > + show_perf_event_uprobe_json(info, json_wtr); > > It would be clearer to me with another switch/case I think (same for > plain output), but I don't mind much. Agree. Will use switch-case instead. > > > + break; > > default: > > break; > > } > > @@ -433,6 +547,71 @@ static void show_kprobe_multi_plain(struct bpf_link_info *info) > > } > > } > > > > +static void show_perf_event_kprobe_plain(struct bpf_link_info *info) > > +{ > > + const char *buf; > > + __u32 retprobe; > > + > > + buf = (const char *)u64_to_ptr(info->kprobe.func_name); > > + if (buf[0] == '\0' && !info->kprobe.addr) > > + return; > > + > > + retprobe = info->kprobe.flags & 0x1; > > + printf("\n\tretprobe %u func_name %s ", retprobe, buf); > > + if (info->kprobe.offset) > > + printf("offset %#x ", info->kprobe.offset); > > + if (info->kprobe.addr) > > + printf("addr %llx ", info->kprobe.addr); > > +} > > + > > +static void show_perf_event_uprobe_plain(struct bpf_link_info *info) > > +{ > > + const char *buf; > > + __u32 retprobe; > > + > > + buf = (const char *)u64_to_ptr(info->uprobe.file_name); > > + if (buf[0] == '\0') > > + return; > > + > > + retprobe = info->uprobe.flags & 0x1; > > + printf("\n\tretprobe %u file_name %s ", retprobe, buf); > > + if (info->uprobe.offset) > > + printf("offset %#x ", info->kprobe.offset); > > +} > > + > > +static void show_perf_event_tp_plain(struct bpf_link_info *info) > > +{ > > + const char *buf; > > + > > + buf = (const char *)u64_to_ptr(info->tracepoint.tp_name); > > + if (buf[0] == '\0') > > + return; > > + > > + printf("\n\ttp_name %s ", buf); > > +} > > + > > +static void show_perf_event_event_plain(struct bpf_link_info *info) > > +{ > > + __u64 config = info->perf_event.config; > > + __u32 type = info->perf_event.type; > > + const char *perf_type, *perf_config; > > + > > + perf_type = perf_type_str(type); > > + if (perf_type) > > + printf("\n\tevent_type %s ", perf_type); > > + else > > + printf("\n\tevent_type %u ", type); > > + > > + perf_config = perf_config_str(type, config); > > + if (perf_config) > > + printf("event_config %s ", perf_config); > > + else > > + printf("event_config %llu ", config); > > + > > + if (type == PERF_TYPE_HW_CACHE && perf_config) > > + free((void *)perf_config); > > +} > > + > > static int show_link_close_plain(int fd, struct bpf_link_info *info) > > { > > struct bpf_prog_info prog_info; > > @@ -481,6 +660,16 @@ static int show_link_close_plain(int fd, struct bpf_link_info *info) > > case BPF_LINK_TYPE_KPROBE_MULTI: > > show_kprobe_multi_plain(info); > > break; > > + case BPF_LINK_TYPE_PERF_EVENT: > > + if (info->perf_link_type == BPF_PERF_LINK_PERF_EVENT) > > + show_perf_event_event_plain(info); > > + else if (info->perf_link_type == BPF_PERF_LINK_TRACEPOINT) > > + show_perf_event_tp_plain(info); > > + else if (info->perf_link_type == BPF_PERF_LINK_KPROBE) > > + show_perf_event_kprobe_plain(info); > > + else if (info->perf_link_type == BPF_PERF_LINK_UPROBE) > > + show_perf_event_uprobe_plain(info); > > + break; > > default: > > break; > > } > > @@ -508,6 +697,7 @@ static int do_show_link(int fd) > > int err; > > > > memset(&info, 0, sizeof(info)); > > + buf[0] = '\0'; > > again: > > err = bpf_link_get_info_by_fd(fd, &info, &len); > > if (err) { > > @@ -542,7 +732,30 @@ static int do_show_link(int fd) > > goto again; > > } > > } > > + if (info.type == BPF_LINK_TYPE_PERF_EVENT) { > > + if (info.perf_link_type == BPF_PERF_LINK_PERF_EVENT) > > + goto out; > > + if (info.perf_link_type == BPF_PERF_LINK_TRACEPOINT && > > + !info.tracepoint.tp_name) { > > + info.tracepoint.tp_name = (unsigned long)&buf; > > + info.tracepoint.name_len = sizeof(buf); > > + goto again; > > + } > > + if (info.perf_link_type == BPF_PERF_LINK_KPROBE && > > + !info.kprobe.func_name) { > > + info.kprobe.func_name = (unsigned long)&buf; > > + info.kprobe.name_len = sizeof(buf); > > + goto again; > > + } > > + if (info.perf_link_type == BPF_PERF_LINK_UPROBE && > > + !info.uprobe.file_name) { > > + info.uprobe.file_name = (unsigned long)&buf; > > + info.uprobe.name_len = sizeof(buf); > > Maybe increase the size of buf to accommodate for long paths? Agree. Should increase it to PATH_MAX. > > > + goto again; > > + } > > + } > > > > +out: > > if (json_output) > > show_link_close_json(fd, &info); > > else > > Thanks for this work! Many thanks for your review.
On Mon, Jun 12, 2023 at 8:16 AM Yafang Shao <laoar.shao@gmail.com> wrote: > > Enhance bpftool to display comprehensive information about exposed > perf_event links, covering uprobe, kprobe, tracepoint, and generic perf > event. The resulting output will include the following details: > > $ tools/bpf/bpftool/bpftool link show > 3: perf_event prog 14 > event_type software event_config cpu-clock > bpf_cookie 0 > pids perf_event(1379330) > 4: perf_event prog 14 > event_type hw-cache event_config LLC-load-misses > bpf_cookie 0 > pids perf_event(1379330) > 5: perf_event prog 14 > event_type hardware event_config cpu-cycles how about "event hardware:cpu-cycles" for events > bpf_cookie 0 > pids perf_event(1379330) > 6: perf_event prog 20 > retprobe 0 file_name /home/yafang/bpf/uprobe/a.out offset 0x1338 for uprobes: "uprobe /home/yafang/bpf/uprobe/a.out+0x1338" for retprobes: "uretprobe /home/yafang/bpf/uprobe/a.out+0x1338" > bpf_cookie 0 > pids uprobe(1379706) > 7: perf_event prog 21 > retprobe 1 file_name /home/yafang/bpf/uprobe/a.out offset 0x1338 > bpf_cookie 0 > pids uprobe(1379706) > 8: perf_event prog 27 > tp_name sched_switch "tracepoint sched_switch" ? > bpf_cookie 0 > pids tracepoint(1381734) > 10: perf_event prog 43 > retprobe 0 func_name kernel_clone addr ffffffffad0a9660 similar to uprobes: "kprobe kernel_clone 0xffffffffad0a9660" "kretprobe kernel_clone 0xffffffffad0a9660" That is, make this more human readable instead of mechanically translated from kernel info? retprobe 1/0 is quite cumbersome, "uprobe" vs "uretprobe" makes more sense? JSON is where it could be completely mechanically translated, IMO. > bpf_cookie 0 > pids kprobe(1384186) > 11: perf_event prog 41 > retprobe 1 func_name kernel_clone addr ffffffffad0a9660 > bpf_cookie 0 > pids kprobe(1384186) > > $ tools/bpf/bpftool/bpftool link show -j > [{"id":3,"type":"perf_event","prog_id":14,"event_type":"software","event_config":"cpu-clock","bpf_cookie":0,"pids":[{"pid":1379330,"comm":"perf_event"}]},{"id":4,"type":"perf_event","prog_id":14,"event_type":"hw-cache","event_config":"LLC-load-misses","bpf_cookie":0,"pids":[{"pid":1379330,"comm":"perf_event"}]},{"id":5,"type":"perf_event","prog_id":14,"event_type":"hardware","event_config":"cpu-cycles","bpf_cookie":0,"pids":[{"pid":1379330,"comm":"perf_event"}]},{"id":6,"type":"perf_event","prog_id":20,"retprobe":0,"file_name":"/home/yafang/bpf/uprobe/a.out","offset":4920,"bpf_cookie":0,"pids":[{"pid":1379706,"comm":"uprobe"}]},{"id":7,"type":"perf_event","prog_id":21,"retprobe":1,"file_name":"/home/yafang/bpf/uprobe/a.out","offset":4920,"bpf_cookie":0,"pids":[{"pid":1379706,"comm":"uprobe"}]},{"id":8,"type":"perf_event","prog_id":27,"tp_name":"sched_switch","bpf_cookie":0,"pids":[{"pid":1381734,"comm":"tracepoint"}]},{"id":10,"type":"perf_event","prog_id":43,"retprobe":0,"func_name":"kernel_clone","offset":0,"addr":18446744072317736544,"bpf_cookie":0,"pids":[{"pid":1384186,"comm":"kprobe"}]},{"id":11,"type":"perf_event","prog_id":41,"retprobe":1,"func_name":"kernel_clone","offset":0,"addr":18446744072317736544,"bpf_cookie":0,"pids":[{"pid":1384186,"comm":"kprobe"}]}] > > For generic perf events, the displayed information in bpftool is limited to > the type and configuration, while other attributes such as sample_period, > sample_freq, etc., are not included. > > The kernel function address won't be exposed if it is not permitted by > kptr_restrict. The result as follows when kptr_restrict is 2. > > $ tools/bpf/bpftool/bpftool link show > 3: perf_event prog 14 > event_type software event_config cpu-clock > 4: perf_event prog 14 > event_type hw-cache event_config LLC-load-misses > 5: perf_event prog 14 > event_type hardware event_config cpu-cycles > 6: perf_event prog 20 > retprobe 0 file_name /home/yafang/bpf/uprobe/a.out offset 0x1338 > 7: perf_event prog 21 > retprobe 1 file_name /home/yafang/bpf/uprobe/a.out offset 0x1338 > 8: perf_event prog 27 > tp_name sched_switch > 10: perf_event prog 43 > retprobe 0 func_name kernel_clone > 11: perf_event prog 41 > retprobe 1 func_name kernel_clone > > Signed-off-by: Yafang Shao <laoar.shao@gmail.com> > --- > tools/bpf/bpftool/link.c | 213 +++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 213 insertions(+) > [...]
On Sat, Jun 17, 2023 at 4:41 AM Andrii Nakryiko <andrii.nakryiko@gmail.com> wrote: > > On Mon, Jun 12, 2023 at 8:16 AM Yafang Shao <laoar.shao@gmail.com> wrote: > > > > Enhance bpftool to display comprehensive information about exposed > > perf_event links, covering uprobe, kprobe, tracepoint, and generic perf > > event. The resulting output will include the following details: > > > > $ tools/bpf/bpftool/bpftool link show > > 3: perf_event prog 14 > > event_type software event_config cpu-clock > > bpf_cookie 0 > > pids perf_event(1379330) > > 4: perf_event prog 14 > > event_type hw-cache event_config LLC-load-misses > > bpf_cookie 0 > > pids perf_event(1379330) > > 5: perf_event prog 14 > > event_type hardware event_config cpu-cycles > > how about > > "event hardware:cpu-cycles" for events Agree. That is better. > > > bpf_cookie 0 > > pids perf_event(1379330) > > 6: perf_event prog 20 > > retprobe 0 file_name /home/yafang/bpf/uprobe/a.out offset 0x1338 > > for uprobes: "uprobe /home/yafang/bpf/uprobe/a.out+0x1338" > for retprobes: "uretprobe /home/yafang/bpf/uprobe/a.out+0x1338" Agree. > > > bpf_cookie 0 > > pids uprobe(1379706) > > 7: perf_event prog 21 > > retprobe 1 file_name /home/yafang/bpf/uprobe/a.out offset 0x1338 > > bpf_cookie 0 > > pids uprobe(1379706) > > 8: perf_event prog 27 > > tp_name sched_switch > > "tracepoint sched_switch" ? Agree. > > > bpf_cookie 0 > > pids tracepoint(1381734) > > 10: perf_event prog 43 > > retprobe 0 func_name kernel_clone addr ffffffffad0a9660 > > similar to uprobes: > > "kprobe kernel_clone 0xffffffffad0a9660" > "kretprobe kernel_clone 0xffffffffad0a9660" > > > That is, make this more human readable instead of mechanically > translated from kernel info? retprobe 1/0 is quite cumbersome, > "uprobe" vs "uretprobe" makes more sense? Agree. Will do it. > > JSON is where it could be completely mechanically translated, IMO. Agree.
On Sat, Jun 17, 2023 at 11:20 AM Yafang Shao <laoar.shao@gmail.com> wrote: > > On Sat, Jun 17, 2023 at 4:41 AM Andrii Nakryiko > <andrii.nakryiko@gmail.com> wrote: > > > > On Mon, Jun 12, 2023 at 8:16 AM Yafang Shao <laoar.shao@gmail.com> wrote: > > > > > > Enhance bpftool to display comprehensive information about exposed > > > perf_event links, covering uprobe, kprobe, tracepoint, and generic perf > > > event. The resulting output will include the following details: > > > > > > $ tools/bpf/bpftool/bpftool link show > > > 3: perf_event prog 14 > > > event_type software event_config cpu-clock > > > bpf_cookie 0 > > > pids perf_event(1379330) > > > 4: perf_event prog 14 > > > event_type hw-cache event_config LLC-load-misses > > > bpf_cookie 0 > > > pids perf_event(1379330) > > > 5: perf_event prog 14 > > > event_type hardware event_config cpu-cycles > > > > how about > > > > "event hardware:cpu-cycles" for events > > Agree. That is better. > > > > > > bpf_cookie 0 > > > pids perf_event(1379330) > > > 6: perf_event prog 20 > > > retprobe 0 file_name /home/yafang/bpf/uprobe/a.out offset 0x1338 > > > > for uprobes: "uprobe /home/yafang/bpf/uprobe/a.out+0x1338" > > for retprobes: "uretprobe /home/yafang/bpf/uprobe/a.out+0x1338" > > Agree. BTW, should we also change the output of `bpftool perf show` that way? - Old $ bpftool perf show pid 11898 fd 7: prog_id 6 kprobe func kernel_clone offset 0 pid 11898 fd 9: prog_id 5 kretprobe func kernel_clone offset 0 pid 11966 fd 9: prog_id 13 uprobe filename /home/dev/waken/bpf/uprobe/a.out offset 4920 pid 11966 fd 11: prog_id 14 uretprobe filename /home/dev/waken/bpf/uprobe/a.out offset 4920 - New ? $ bpftool perf show pid 11898 fd 7: prog_id 6 kprobe kernel_clone pid 11898 fd 9: prog_id 5 kretprobe kernel_clone pid 11966 fd 9: prog_id 13 uprobe /home/dev/waken/bpf/uprobe/a.out+0x1338 pid 11966 fd 11: prog_id 14 uretprobe /home/dev/waken/bpf/uprobe/a.out+0x1338 > > > > > > bpf_cookie 0 > > > pids uprobe(1379706) > > > 7: perf_event prog 21 > > > retprobe 1 file_name /home/yafang/bpf/uprobe/a.out offset 0x1338 > > > bpf_cookie 0 > > > pids uprobe(1379706) > > > 8: perf_event prog 27 > > > tp_name sched_switch > > > > "tracepoint sched_switch" ? > > Agree. > > > > > > bpf_cookie 0 > > > pids tracepoint(1381734) > > > 10: perf_event prog 43 > > > retprobe 0 func_name kernel_clone addr ffffffffad0a9660 > > > > similar to uprobes: > > > > "kprobe kernel_clone 0xffffffffad0a9660" > > "kretprobe kernel_clone 0xffffffffad0a9660" > > > > > > That is, make this more human readable instead of mechanically > > translated from kernel info? retprobe 1/0 is quite cumbersome, > > "uprobe" vs "uretprobe" makes more sense? > > Agree. Will do it. > > > > > JSON is where it could be completely mechanically translated, IMO. > > Agree. > > -- > Regards > Yafang
diff --git a/tools/bpf/bpftool/link.c b/tools/bpf/bpftool/link.c index 0015582..c16f71d 100644 --- a/tools/bpf/bpftool/link.c +++ b/tools/bpf/bpftool/link.c @@ -15,6 +15,7 @@ #include "json_writer.h" #include "main.h" #include "xlated_dumper.h" +#include "perf.h" static struct hashmap *link_table; static struct dump_data dd = {}; @@ -207,6 +208,109 @@ static int cmp_u64(const void *A, const void *B) jsonw_end_array(json_wtr); } +static void +show_perf_event_kprobe_json(struct bpf_link_info *info, json_writer_t *wtr) +{ + jsonw_uint_field(wtr, "retprobe", info->kprobe.flags & 0x1); + jsonw_string_field(wtr, "func_name", + u64_to_ptr(info->kprobe.func_name)); + jsonw_uint_field(wtr, "offset", info->kprobe.offset); + jsonw_uint_field(wtr, "addr", info->kprobe.addr); +} + +static void +show_perf_event_uprobe_json(struct bpf_link_info *info, json_writer_t *wtr) +{ + jsonw_uint_field(wtr, "retprobe", info->uprobe.flags & 0x1); + jsonw_string_field(wtr, "file_name", + u64_to_ptr(info->uprobe.file_name)); + jsonw_uint_field(wtr, "offset", info->uprobe.offset); +} + +static void +show_perf_event_tp_json(struct bpf_link_info *info, json_writer_t *wtr) +{ + jsonw_string_field(wtr, "tp_name", + u64_to_ptr(info->tracepoint.tp_name)); +} + +static const char *perf_config_hw_cache_str(__u64 config) +{ +#define PERF_HW_CACHE_LEN 128 + const char *hw_cache, *result, *op; + char *str = malloc(PERF_HW_CACHE_LEN); + + if (!str) { + p_err("mem alloc failed"); + return NULL; + } + hw_cache = perf_hw_cache_str(config & 0xff); + if (hw_cache) + snprintf(str, PERF_HW_CACHE_LEN, "%s-", hw_cache); + else + snprintf(str, PERF_HW_CACHE_LEN, "%lld-", config & 0xff); + op = perf_hw_cache_op_str((config >> 8) & 0xff); + if (op) + snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str), + "%s-", op); + else + snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str), + "%lld-", (config >> 8) & 0xff); + result = perf_hw_cache_op_result_str(config >> 16); + if (result) + snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str), + "%s", result); + else + snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str), + "%lld", config >> 16); + + return str; +} + +static const char *perf_config_str(__u32 type, __u64 config) +{ + const char *perf_config; + + switch (type) { + case PERF_TYPE_HARDWARE: + perf_config = perf_hw_str(config); + break; + case PERF_TYPE_SOFTWARE: + perf_config = perf_sw_str(config); + break; + case PERF_TYPE_HW_CACHE: + perf_config = perf_config_hw_cache_str(config); + break; + default: + perf_config = NULL; + break; + } + return perf_config; +} + +static void +show_perf_event_event_json(struct bpf_link_info *info, json_writer_t *wtr) +{ + __u64 config = info->perf_event.config; + __u32 type = info->perf_event.type; + const char *perf_type, *perf_config; + + perf_type = perf_type_str(type); + if (perf_type) + jsonw_string_field(wtr, "event_type", perf_type); + else + jsonw_uint_field(wtr, "event_type", type); + + perf_config = perf_config_str(type, config); + if (perf_config) + jsonw_string_field(wtr, "event_config", perf_config); + else + jsonw_uint_field(wtr, "event_config", config); + + if (type == PERF_TYPE_HW_CACHE && perf_config) + free((void *)perf_config); +} + static int show_link_close_json(int fd, struct bpf_link_info *info) { struct bpf_prog_info prog_info; @@ -262,6 +366,16 @@ static int show_link_close_json(int fd, struct bpf_link_info *info) case BPF_LINK_TYPE_KPROBE_MULTI: show_kprobe_multi_json(info, json_wtr); break; + case BPF_LINK_TYPE_PERF_EVENT: + if (info->perf_link_type == BPF_PERF_LINK_PERF_EVENT) + show_perf_event_event_json(info, json_wtr); + else if (info->perf_link_type == BPF_PERF_LINK_TRACEPOINT) + show_perf_event_tp_json(info, json_wtr); + else if (info->perf_link_type == BPF_PERF_LINK_KPROBE) + show_perf_event_kprobe_json(info, json_wtr); + else if (info->perf_link_type == BPF_PERF_LINK_UPROBE) + show_perf_event_uprobe_json(info, json_wtr); + break; default: break; } @@ -433,6 +547,71 @@ static void show_kprobe_multi_plain(struct bpf_link_info *info) } } +static void show_perf_event_kprobe_plain(struct bpf_link_info *info) +{ + const char *buf; + __u32 retprobe; + + buf = (const char *)u64_to_ptr(info->kprobe.func_name); + if (buf[0] == '\0' && !info->kprobe.addr) + return; + + retprobe = info->kprobe.flags & 0x1; + printf("\n\tretprobe %u func_name %s ", retprobe, buf); + if (info->kprobe.offset) + printf("offset %#x ", info->kprobe.offset); + if (info->kprobe.addr) + printf("addr %llx ", info->kprobe.addr); +} + +static void show_perf_event_uprobe_plain(struct bpf_link_info *info) +{ + const char *buf; + __u32 retprobe; + + buf = (const char *)u64_to_ptr(info->uprobe.file_name); + if (buf[0] == '\0') + return; + + retprobe = info->uprobe.flags & 0x1; + printf("\n\tretprobe %u file_name %s ", retprobe, buf); + if (info->uprobe.offset) + printf("offset %#x ", info->kprobe.offset); +} + +static void show_perf_event_tp_plain(struct bpf_link_info *info) +{ + const char *buf; + + buf = (const char *)u64_to_ptr(info->tracepoint.tp_name); + if (buf[0] == '\0') + return; + + printf("\n\ttp_name %s ", buf); +} + +static void show_perf_event_event_plain(struct bpf_link_info *info) +{ + __u64 config = info->perf_event.config; + __u32 type = info->perf_event.type; + const char *perf_type, *perf_config; + + perf_type = perf_type_str(type); + if (perf_type) + printf("\n\tevent_type %s ", perf_type); + else + printf("\n\tevent_type %u ", type); + + perf_config = perf_config_str(type, config); + if (perf_config) + printf("event_config %s ", perf_config); + else + printf("event_config %llu ", config); + + if (type == PERF_TYPE_HW_CACHE && perf_config) + free((void *)perf_config); +} + static int show_link_close_plain(int fd, struct bpf_link_info *info) { struct bpf_prog_info prog_info; @@ -481,6 +660,16 @@ static int show_link_close_plain(int fd, struct bpf_link_info *info) case BPF_LINK_TYPE_KPROBE_MULTI: show_kprobe_multi_plain(info); break; + case BPF_LINK_TYPE_PERF_EVENT: + if (info->perf_link_type == BPF_PERF_LINK_PERF_EVENT) + show_perf_event_event_plain(info); + else if (info->perf_link_type == BPF_PERF_LINK_TRACEPOINT) + show_perf_event_tp_plain(info); + else if (info->perf_link_type == BPF_PERF_LINK_KPROBE) + show_perf_event_kprobe_plain(info); + else if (info->perf_link_type == BPF_PERF_LINK_UPROBE) + show_perf_event_uprobe_plain(info); + break; default: break; } @@ -508,6 +697,7 @@ static int do_show_link(int fd) int err; memset(&info, 0, sizeof(info)); + buf[0] = '\0'; again: err = bpf_link_get_info_by_fd(fd, &info, &len); if (err) { @@ -542,7 +732,30 @@ static int do_show_link(int fd) goto again; } } + if (info.type == BPF_LINK_TYPE_PERF_EVENT) { + if (info.perf_link_type == BPF_PERF_LINK_PERF_EVENT) + goto out; + if (info.perf_link_type == BPF_PERF_LINK_TRACEPOINT && + !info.tracepoint.tp_name) { + info.tracepoint.tp_name = (unsigned long)&buf; + info.tracepoint.name_len = sizeof(buf); + goto again; + } + if (info.perf_link_type == BPF_PERF_LINK_KPROBE && + !info.kprobe.func_name) { + info.kprobe.func_name = (unsigned long)&buf; + info.kprobe.name_len = sizeof(buf); + goto again; + } + if (info.perf_link_type == BPF_PERF_LINK_UPROBE && + !info.uprobe.file_name) { + info.uprobe.file_name = (unsigned long)&buf; + info.uprobe.name_len = sizeof(buf); + goto again; + } + } +out: if (json_output) show_link_close_json(fd, &info); else
Enhance bpftool to display comprehensive information about exposed perf_event links, covering uprobe, kprobe, tracepoint, and generic perf event. The resulting output will include the following details: $ tools/bpf/bpftool/bpftool link show 3: perf_event prog 14 event_type software event_config cpu-clock bpf_cookie 0 pids perf_event(1379330) 4: perf_event prog 14 event_type hw-cache event_config LLC-load-misses bpf_cookie 0 pids perf_event(1379330) 5: perf_event prog 14 event_type hardware event_config cpu-cycles bpf_cookie 0 pids perf_event(1379330) 6: perf_event prog 20 retprobe 0 file_name /home/yafang/bpf/uprobe/a.out offset 0x1338 bpf_cookie 0 pids uprobe(1379706) 7: perf_event prog 21 retprobe 1 file_name /home/yafang/bpf/uprobe/a.out offset 0x1338 bpf_cookie 0 pids uprobe(1379706) 8: perf_event prog 27 tp_name sched_switch bpf_cookie 0 pids tracepoint(1381734) 10: perf_event prog 43 retprobe 0 func_name kernel_clone addr ffffffffad0a9660 bpf_cookie 0 pids kprobe(1384186) 11: perf_event prog 41 retprobe 1 func_name kernel_clone addr ffffffffad0a9660 bpf_cookie 0 pids kprobe(1384186) $ tools/bpf/bpftool/bpftool link show -j [{"id":3,"type":"perf_event","prog_id":14,"event_type":"software","event_config":"cpu-clock","bpf_cookie":0,"pids":[{"pid":1379330,"comm":"perf_event"}]},{"id":4,"type":"perf_event","prog_id":14,"event_type":"hw-cache","event_config":"LLC-load-misses","bpf_cookie":0,"pids":[{"pid":1379330,"comm":"perf_event"}]},{"id":5,"type":"perf_event","prog_id":14,"event_type":"hardware","event_config":"cpu-cycles","bpf_cookie":0,"pids":[{"pid":1379330,"comm":"perf_event"}]},{"id":6,"type":"perf_event","prog_id":20,"retprobe":0,"file_name":"/home/yafang/bpf/uprobe/a.out","offset":4920,"bpf_cookie":0,"pids":[{"pid":1379706,"comm":"uprobe"}]},{"id":7,"type":"perf_event","prog_id":21,"retprobe":1,"file_name":"/home/yafang/bpf/uprobe/a.out","offset":4920,"bpf_cookie":0,"pids":[{"pid":1379706,"comm":"uprobe"}]},{"id":8,"type":"perf_event","prog_id":27,"tp_name":"sched_switch","bpf_cookie":0,"pids":[{"pid":1381734,"comm":"tracepoint"}]},{"id":10,"type":"perf_event","prog_id":43,"retprobe":0,"func_name":"kernel_clone","offset":0,"addr":18446744072317736544,"bpf_cookie":0,"pids":[{"pid":1384186,"comm":"kprobe"}]},{"id":11,"type":"perf_event","prog_id":41,"retprobe":1,"func_name":"kernel_clone","offset":0,"addr":18446744072317736544,"bpf_cookie":0,"pids":[{"pid":1384186,"comm":"kprobe"}]}] For generic perf events, the displayed information in bpftool is limited to the type and configuration, while other attributes such as sample_period, sample_freq, etc., are not included. The kernel function address won't be exposed if it is not permitted by kptr_restrict. The result as follows when kptr_restrict is 2. $ tools/bpf/bpftool/bpftool link show 3: perf_event prog 14 event_type software event_config cpu-clock 4: perf_event prog 14 event_type hw-cache event_config LLC-load-misses 5: perf_event prog 14 event_type hardware event_config cpu-cycles 6: perf_event prog 20 retprobe 0 file_name /home/yafang/bpf/uprobe/a.out offset 0x1338 7: perf_event prog 21 retprobe 1 file_name /home/yafang/bpf/uprobe/a.out offset 0x1338 8: perf_event prog 27 tp_name sched_switch 10: perf_event prog 43 retprobe 0 func_name kernel_clone 11: perf_event prog 41 retprobe 1 func_name kernel_clone Signed-off-by: Yafang Shao <laoar.shao@gmail.com> --- tools/bpf/bpftool/link.c | 213 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 213 insertions(+)