On 16/10/2024 7:40 am, Metin Kaya wrote:
On 15/10/2024 8:11 pm, Steven Rostedt wrote:From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx> The function tracefs_dynevent_get_all() will only look at the dynamic_events file if it exists to find matching probes. But becauseuprobes and kprobes both use the same prefix "p" as well as uretprobes andkretprobes (with prefix "r"), it cannot use the dynamic_events file to differentiate between the two. Have kprobes and uprobes always use their own files (kprobe_events and uprobe_events) even if dynamic_events file exists. Also cleaned up the code to be a bit more efficient.Link: https://lore.kernel.org/all/20241015123831.347ff0f4@xxxxxxxxxxxxxxxxxx/Fixes: b04f18b005c6b ("libtracefs: New APIs for dynamic events") Reported-by: Metin Kaya <metin.kaya@xxxxxxx> Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx> --- src/tracefs-dynevents.c | 113 +++++++++++++++++++++------------------- 1 file changed, 60 insertions(+), 53 deletions(-) diff --git a/src/tracefs-dynevents.c b/src/tracefs-dynevents.c index 85c1fcd9d5d5..6b9ba539fde3 100644 --- a/src/tracefs-dynevents.c +++ b/src/tracefs-dynevents.c@@ -34,23 +34,21 @@ static int dyn_generic_del(struct dyn_events_desc *, struct tracefs_dynevent *); static int dyn_synth_del(struct dyn_events_desc *, struct tracefs_dynevent *);struct dyn_events_desc { - enum tracefs_dynevent_type type; - const char *file; - const char *prefix; + enum tracefs_dynevent_type type; + const char *file; + const char *prefix;int (*del)(struct dyn_events_desc *desc, struct tracefs_dynevent *dyn);int (*parse)(struct dyn_events_desc *desc, const char *group, char *line, struct tracefs_dynevent **ret_dyn); } dynevents[] = {- {TRACEFS_DYNEVENT_KPROBE, KPROBE_EVENTS, "p", dyn_generic_del, dyn_generic_parse}, + {TRACEFS_DYNEVENT_KPROBE, KPROBE_EVENTS, "p", dyn_generic_del, dyn_generic_parse}, {TRACEFS_DYNEVENT_KRETPROBE, KPROBE_EVENTS, "r", dyn_generic_del, dyn_generic_parse}, - {TRACEFS_DYNEVENT_UPROBE, UPROBE_EVENTS, "p", dyn_generic_del, dyn_generic_parse}, + {TRACEFS_DYNEVENT_UPROBE, UPROBE_EVENTS, "p", dyn_generic_del, dyn_generic_parse}, {TRACEFS_DYNEVENT_URETPROBE, UPROBE_EVENTS, "r", dyn_generic_del, dyn_generic_parse}, - {TRACEFS_DYNEVENT_EPROBE, "", "e", dyn_generic_del, dyn_generic_parse}, - {TRACEFS_DYNEVENT_SYNTH, SYNTH_EVENTS, "", dyn_synth_del, dyn_synth_parse}, + {TRACEFS_DYNEVENT_EPROBE, "", "e", dyn_generic_del, dyn_generic_parse}, + {TRACEFS_DYNEVENT_SYNTH, SYNTH_EVENTS, "", dyn_synth_del, dyn_synth_parse},}; - -static int dyn_generic_del(struct dyn_events_desc *desc, struct tracefs_dynevent *dyn){ char *str; @@ -280,8 +278,13 @@ static void init_devent_desc(void) return; /* Use ftrace dynamic_events, if available */ - for (i = 0; i < EVENT_INDEX(TRACEFS_DYNEVENT_MAX); i++) + for (i = 0; i < EVENT_INDEX(TRACEFS_DYNEVENT_MAX); i++) { + /* kprobes and uprobes do not use default file */ + if (dynevents[i].prefix[0] == 'p' || + dynevents[i].prefix[0] == 'r') + continue; dynevents[i].file = DYNEVENTS_EVENTS; + } dynevents[EVENT_INDEX(TRACEFS_DYNEVENT_SYNTH)].prefix = "s"; }@@ -480,16 +483,15 @@ int tracefs_dynevent_destroy(struct tracefs_dynevent *devent, bool force)return desc->del(desc, devent); }-static int get_all_dynevents(enum tracefs_dynevent_type type, const char *system,- struct tracefs_dynevent ***ret_all)+static int get_dynevent(enum tracefs_dynevent_type type, const char *system,+ struct tracefs_dynevent ***ret_all, int count) { struct dyn_events_desc *desc; - struct tracefs_dynevent *devent, **tmp, **all = NULL; + struct tracefs_dynevent *devent, **tmp, **all; char *content; - int count = 0; char *line; char *next; - int ret; + int ret = -1; desc = get_devent_desc(type); if (!desc)@@ -499,6 +501,9 @@ static int get_all_dynevents(enum tracefs_dynevent_type type, const char *systemif (!content) return -1; + if (ret_all) + all = *ret_all; + line = content; do { next = strchr(line, '\n');@@ -507,11 +512,12 @@ static int get_all_dynevents(enum tracefs_dynevent_type type, const char *system ret = desc->parse(desc, system, line, ret_all ? &devent : NULL);if (!ret) { if (ret_all) { - tmp = realloc(all, (count + 1) * sizeof(*tmp)); + tmp = realloc(all, (count + 2) * sizeof(*tmp)); if (!tmp) - goto error; + break; all = tmp; all[count] = devent; + all[count + 1] = NULL; } count++; }@@ -521,12 +527,38 @@ static int get_all_dynevents(enum tracefs_dynevent_type type, const char *systemfree(content); if (ret_all) *ret_all = all; + return count; +} -error: - free(content); - free(all); - return -1;+static int get_all_dynevents(enum tracefs_dynevent_type type, const char *system,+ struct tracefs_dynevent ***ret_all) +{ + int count = 0; + int i; + + if (ret_all) + *ret_all = NULL; + + for (i = 0; i < EVENT_INDEX(TRACEFS_DYNEVENT_MAX); i++) { + if (!((1 << i) & type)) + continue; + + count = get_dynevent((1 << i), system, ret_all, count); + if (count < 0) { + count = 0; + break; + } + } + + if (!count) { + if (ret_all) { + free(*ret_all); + *ret_all = NULL; + } + count = -1; + } + return count; } /**@@ -561,41 +593,16 @@ void tracefs_dynevent_list_free(struct tracefs_dynevent **events)struct tracefs_dynevent ** tracefs_dynevent_get_all(unsigned int types, const char *system) { - struct tracefs_dynevent **events, **tmp, **all_events = NULL; - int count, all = 0; - int i; + struct tracefs_dynevent **events; + int count; - for (i = 1; i < TRACEFS_DYNEVENT_MAX; i <<= 1) { - if (types) { - if (i > types) - break; - if (!(types & i)) - continue; - } - count = get_all_dynevents(i, system, &events); - if (count > 0) { - tmp = realloc(all_events, (all + count + 1) * sizeof(*tmp)); - if (!tmp) - goto error; - all_events = tmp; - memcpy(all_events + all, events, count * sizeof(*events)); - all += count; - /* Add a NULL pointer at the end */ - all_events[all] = NULL; - free(events); - } + count = get_all_dynevents(types, system, &events); + if (count <= 0) { + free(events); + return NULL; } - return all_events; - -error: - free(events); - if (all_events) { - for (i = 0; i < all; i++) - free(all_events[i]); - free(all_events); - } - return NULL; + return events; } /**I could successfully apply the patch on 4cbebed79b1f ("libtracefs: Documentation: Add missing documentation to meson.build").The unit tests at [1] passes with this patch.Just for the records, there are some unit test failures in libtracefs (they were there even before the patch):$ sudo ./utest/trace-utest CUnit - A unit testing framework for C - Version 2.1-3 http://cunit.sourceforge.net/ Memory mapped buffers not supported Suite: tracefs library Test: Test tracefs/debugfs mounting ...FAILED 1. tracefs-utest.c:1806 - ret == 0 Test: trace cpu read ...passed Test: trace cpu read_buf_percent ...passed Test: trace cpu pipe ...passed Test: trace pid events filter ...passed Test: trace pid function filter ...passed Test: trace sql ...passed Test: trace sql trace onmax ...passed Test: trace sql trace onchange ...passed Test: trace sql snapshot onmax ...passed Test: trace sql snapshot onchange ...passed Test: trace sql save onmax ...passed Test: trace sql save onchange ...passed Test: trace sql trace and snapshot onmax ...passed Test: trace sql trace and snapshot onchange ...passed Test: tracing file / directory APIs ...passed Test: instance file / directory APIs ...passed Test: instance file descriptor ...passed Test: instance reset ...passed Test: systems and events APIs ...passed Test: tracefs_iterate_snapshot_events API ...passed Test: tracefs_iterate_raw_events API ...FAILED 1. tracefs-utest.c:235 - ret == sizeof(struct test_sample) 2. tracefs-utest.c:235 - ret == sizeof(struct test_sample) Test: Follow events ...passed Test: Follow events clear ...passed Test: tracefs_tracers API ...passed Test: tracefs_local events API ...passed Test: tracefs_instances_walk API ...passed Test: tracefs_get_clock API ...passed Test: tracing on / off ...passed Test: tracing options ...passed Test: custom system directory ...passed Test: ftrace marker ...passed Test: kprobes ...passed Test: synthetic events ...passed Test: eprobes ...passed Test: uprobes ...FAILED 1. tracefs-utest.c:2222 - ret == 0 2. tracefs-utest.c:2222 - ret == 0 Run Summary: Type Total Ran Passed Failed Inactive suites 1 1 n/a 0 0 tests 36 36 33 3 0 asserts 30341119 30341119 30341114 5 n/a Elapsed time = 124.937 seconds With that, Reviewed-by: Metin Kaya <metin.kaya@xxxxxxx> Thanks a lot for fixing it promptly![1] https://lore.kernel.org/all/20241015140840.4183007-1-metin.kaya@xxxxxxx/
Sorry, I need to revoke my Reviewed-by. Because, "trace-cmd reset" cannot destroy uretprobes after this patch.
# cd /sys/kernel/tracing/ /sys/kernel/tracing # cat uprobe_events /sys/kernel/tracing # echo 'r /bin/bash:0x4245c0' > uprobe_events /sys/kernel/tracing # cat uprobe_events r:uprobes/p_bash_0x4245c0 /bin/bash:0x00000000004245c0 /sys/kernel/tracing # trace-cmd reset /sys/kernel/tracing # cat uprobe_events r:uprobes/p_bash_0x4245c0 /bin/bash:0x00000000004245c0OTOH, "trace-cmd reset" is able to destroy uretprobes if there is also a kprobe in addition to a uretprobe:
/sys/kernel/tracing # cat dynamic_events /sys/kernel/tracing # cat uprobe_events /sys/kernel/tracing # echo 'p do_sys_open' > kprobe_events /sys/kernel/tracing # echo 'r /bin/bash:0x4245c0' > uprobe_events /sys/kernel/tracing # cat dynamic_events p:kprobes/p_do_sys_open_0 do_sys_open r:uprobes/p_bash_0x4245c0 /bin/bash:0x00000000004245c0 /sys/kernel/tracing # cat uprobe_events r:uprobes/p_bash_0x4245c0 /bin/bash:0x00000000004245c0 /sys/kernel/tracing # trace-cmd reset /sys/kernel/tracing # cat dynamic_events /sys/kernel/tracing # cat uprobe_events /sys/kernel/tracing #
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