From 6fe7c745f2acb73e4cc961d7f91125eef5a8861f Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Tue, 10 Aug 2021 11:07:14 +0900 Subject: tracing/boot: Fix a hist trigger dependency for boot time tracing Fixes a build error when CONFIG_HIST_TRIGGERS=n with boot-time tracing. Since the trigger_process_regex() is defined only when CONFIG_HIST_TRIGGERS=y, if it is disabled, the 'actions' event option also must be disabled. Link: https://lkml.kernel.org/r/162856123376.203126.582144262622247352.stgit@devnote2 Fixes: 81a59555ff15 ("tracing/boot: Add per-event settings") Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_boot.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) (limited to 'kernel/trace/trace_boot.c') diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index 94ef2d099e32..d713714cba67 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -205,12 +205,15 @@ trace_boot_init_one_event(struct trace_array *tr, struct xbc_node *gnode, pr_err("Failed to apply filter: %s\n", buf); } - xbc_node_for_each_array_value(enode, "actions", anode, p) { - if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) - pr_err("action string is too long: %s\n", p); - else if (trigger_process_regex(file, buf) < 0) - pr_err("Failed to apply an action: %s\n", buf); - } + if (IS_ENABLED(CONFIG_HIST_TRIGGERS)) { + xbc_node_for_each_array_value(enode, "actions", anode, p) { + if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) + pr_err("action string is too long: %s\n", p); + else if (trigger_process_regex(file, buf) < 0) + pr_err("Failed to apply an action: %s\n", buf); + } + } else if (xbc_node_find_value(enode, "actions", NULL)) + pr_err("Failed to apply event actions because CONFIG_HIST_TRIGGERS is not set.\n"); if (xbc_node_find_value(enode, "enable", NULL)) { if (trace_event_enable_disable(file, 1, 0) < 0) -- cgit v1.2.3 From e66ed86ca6c52488249e95f7b3a6a3d7d6ab5e1e Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Tue, 10 Aug 2021 11:07:21 +0900 Subject: tracing/boot: Add per-event histogram action options Add a hist-trigger action syntax support to boot-time tracing. Currently, boot-time tracing supports per-event actions as option strings. However, for the histogram action, it has a special syntax and usually needs a long action definition. To make it readable and fit to the bootconfig syntax, this introduces a new options for histogram. Here are the histogram action options for boot-time tracing. ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist { keys = [,...] values = [,...] sort = [,...] size = name = var { = ... } pause|continue|clear onmax|onchange { var = ; [= ] } onmatch { event = ; [= ] } filter = } Where is one of below; trace = , [, ...] save = [, ...] snapshot Link: https://lkml.kernel.org/r/162856124106.203126.10501871028479029087.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_boot.c | 231 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 231 insertions(+) (limited to 'kernel/trace/trace_boot.c') diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index d713714cba67..3d0e51368f51 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -171,6 +171,231 @@ trace_boot_add_synth_event(struct xbc_node *node, const char *event) } #endif +#ifdef CONFIG_HIST_TRIGGERS +static int __init __printf(3, 4) +append_printf(char **bufp, char *end, const char *fmt, ...) +{ + va_list args; + int ret; + + if (*bufp == end) + return -ENOSPC; + + va_start(args, fmt); + ret = vsnprintf(*bufp, end - *bufp, fmt, args); + if (ret < end - *bufp) { + *bufp += ret; + } else { + *bufp = end; + ret = -ERANGE; + } + va_end(args); + + return ret; +} + +static int __init +append_str_nospace(char **bufp, char *end, const char *str) +{ + char *p = *bufp; + int len; + + while (p < end - 1 && *str != '\0') { + if (!isspace(*str)) + *(p++) = *str; + str++; + } + *p = '\0'; + if (p == end - 1) { + *bufp = end; + return -ENOSPC; + } + len = p - *bufp; + *bufp = p; + return (int)len; +} + +static int __init +trace_boot_hist_add_array(struct xbc_node *hnode, char **bufp, + char *end, const char *key) +{ + struct xbc_node *knode, *anode; + const char *p; + char sep; + + knode = xbc_node_find_child(hnode, key); + if (knode) { + anode = xbc_node_get_child(knode); + if (!anode) { + pr_err("hist.%s requires value(s).\n", key); + return -EINVAL; + } + + append_printf(bufp, end, ":%s", key); + sep = '='; + xbc_array_for_each_value(anode, p) { + append_printf(bufp, end, "%c%s", sep, p); + if (sep == '=') + sep = ','; + } + } else + return -ENOENT; + + return 0; +} + +static int __init +trace_boot_hist_add_handler(struct xbc_node *hnode, char **bufp, + char *end, const char *param) +{ + struct xbc_node *knode, *anode; + const char *p; + char sep; + + /* Compose 'handler' parameter */ + p = xbc_node_find_value(hnode, param, NULL); + if (!p) { + pr_err("hist.%s requires '%s' option.\n", + xbc_node_get_data(hnode), param); + return -EINVAL; + } + append_printf(bufp, end, ":%s(%s)", xbc_node_get_data(hnode), p); + + /* Compose 'action' parameter */ + knode = xbc_node_find_child(hnode, "trace"); + if (!knode) + knode = xbc_node_find_child(hnode, "save"); + + if (knode) { + anode = xbc_node_get_child(knode); + if (!anode || !xbc_node_is_value(anode)) { + pr_err("hist.%s.%s requires value(s).\n", + xbc_node_get_data(hnode), + xbc_node_get_data(knode)); + return -EINVAL; + } + + append_printf(bufp, end, ".%s", xbc_node_get_data(knode)); + sep = '('; + xbc_array_for_each_value(anode, p) { + append_printf(bufp, end, "%c%s", sep, p); + if (sep == '(') + sep = ','; + } + append_printf(bufp, end, ")"); + } else if (xbc_node_find_child(hnode, "snapshot")) { + append_printf(bufp, end, ".snapshot()"); + } else { + pr_err("hist.%s requires an action.\n", + xbc_node_get_data(hnode)); + return -EINVAL; + } + + return 0; +} + +/* + * Histogram boottime tracing syntax. + * + * ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist { + * keys = [,...] + * values = [,...] + * sort = [,...] + * size = + * name = + * var { = ... } + * pause|continue|clear + * onmax|onchange { var = ; [= ] } + * onmatch { event = ; [= ] } + * filter = + * } + * + * Where are; + * + * trace = , [, ...] + * save = [, ...] + * snapshot + */ +static int __init +trace_boot_compose_hist_cmd(struct xbc_node *hnode, char *buf, size_t size) +{ + struct xbc_node *node, *knode; + char *end = buf + size; + const char *p; + int ret = 0; + + append_printf(&buf, end, "hist"); + + ret = trace_boot_hist_add_array(hnode, &buf, end, "keys"); + if (ret < 0) { + if (ret == -ENOENT) + pr_err("hist requires keys.\n"); + return -EINVAL; + } + + ret = trace_boot_hist_add_array(hnode, &buf, end, "values"); + if (ret == -EINVAL) + return ret; + ret = trace_boot_hist_add_array(hnode, &buf, end, "sort"); + if (ret == -EINVAL) + return ret; + + p = xbc_node_find_value(hnode, "size", NULL); + if (p) + append_printf(&buf, end, ":size=%s", p); + + p = xbc_node_find_value(hnode, "name", NULL); + if (p) + append_printf(&buf, end, ":name=%s", p); + + node = xbc_node_find_child(hnode, "var"); + if (node) { + xbc_node_for_each_key_value(node, knode, p) { + /* Expression must not include spaces. */ + append_printf(&buf, end, ":%s=", + xbc_node_get_data(knode)); + append_str_nospace(&buf, end, p); + } + } + + /* Histogram control attributes (mutual exclusive) */ + if (xbc_node_find_child(hnode, "pause")) + append_printf(&buf, end, ":pause"); + else if (xbc_node_find_child(hnode, "continue")) + append_printf(&buf, end, ":continue"); + else if (xbc_node_find_child(hnode, "clear")) + append_printf(&buf, end, ":clear"); + + /* Histogram handler and actions */ + node = xbc_node_find_child(hnode, "onmax"); + if (node && trace_boot_hist_add_handler(node, &buf, end, "var") < 0) + return -EINVAL; + node = xbc_node_find_child(hnode, "onchange"); + if (node && trace_boot_hist_add_handler(node, &buf, end, "var") < 0) + return -EINVAL; + node = xbc_node_find_child(hnode, "onmatch"); + if (node && trace_boot_hist_add_handler(node, &buf, end, "event") < 0) + return -EINVAL; + + p = xbc_node_find_value(hnode, "filter", NULL); + if (p) + append_printf(&buf, end, " if %s", p); + + if (buf == end) { + pr_err("hist exceeds the max command length.\n"); + return -E2BIG; + } + + return 0; +} +#else +static int __init +trace_boot_compose_hist_cmd(struct xbc_node *hnode, char *buf, size_t size) +{ + return -EOPNOTSUPP; +} +#endif + static void __init trace_boot_init_one_event(struct trace_array *tr, struct xbc_node *gnode, struct xbc_node *enode) @@ -212,6 +437,12 @@ trace_boot_init_one_event(struct trace_array *tr, struct xbc_node *gnode, else if (trigger_process_regex(file, buf) < 0) pr_err("Failed to apply an action: %s\n", buf); } + anode = xbc_node_find_child(enode, "hist"); + if (anode && + trace_boot_compose_hist_cmd(anode, buf, ARRAY_SIZE(buf)) == 0) { + if (trigger_process_regex(file, buf) < 0) + pr_err("Failed to apply hist trigger: %s\n", buf); + } } else if (xbc_node_find_value(enode, "actions", NULL)) pr_err("Failed to apply event actions because CONFIG_HIST_TRIGGERS is not set.\n"); -- cgit v1.2.3 From 8993665abcce793f00815b3504a486dce70cc2b9 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Tue, 10 Aug 2021 11:07:29 +0900 Subject: tracing/boot: Support multiple handlers for per-event histogram Support multiple handlers for per-event histogram in boot-time tracing. Since the histogram can register multiple same handler-actions with different parameters, this expands the syntax to support such cases. With this update, the 'onmax', 'onchange' and 'onmatch' handler subkeys under per-event histogram option will take a number subkeys optionally as below. (see [.N]) ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist { onmax|onchange[.N] { var = ; [= ] } onmatch[.N] { event = ; [= ] } } The 'N' must be a digit (or digit started word). Thus user can add several handler-actions to the histogram, for example, ftrace.event.SOMEGROUP.SOMEEVENT.hist { keys = SOME_ID; lat = common_timestamp.usecs-$ts0 onmatch.1 { event = GROUP1.STARTEVENT1 trace = latency_event, SOME_ID, $lat } onmatch.2 { event = GROUP2.STARTEVENT2 trace = latency_event, SOME_ID, $lat } } Then, it can trace the elapsed time from GROUP1.STARTEVENT1 to SOMEGROUP.SOMEEVENT, and from GROUP2.STARTEVENT2 to SOMEGROUP.SOMEEVENT with SOME_ID key. Link: https://lkml.kernel.org/r/162856124905.203126.14913731908137885922.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_boot.c | 43 +++++++++++++++++++++++++++++++++++-------- 1 file changed, 35 insertions(+), 8 deletions(-) (limited to 'kernel/trace/trace_boot.c') diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index 3d0e51368f51..f024f27b3602 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -245,8 +245,9 @@ trace_boot_hist_add_array(struct xbc_node *hnode, char **bufp, } static int __init -trace_boot_hist_add_handler(struct xbc_node *hnode, char **bufp, - char *end, const char *param) +trace_boot_hist_add_one_handler(struct xbc_node *hnode, char **bufp, + char *end, const char *handler, + const char *param) { struct xbc_node *knode, *anode; const char *p; @@ -259,7 +260,7 @@ trace_boot_hist_add_handler(struct xbc_node *hnode, char **bufp, xbc_node_get_data(hnode), param); return -EINVAL; } - append_printf(bufp, end, ":%s(%s)", xbc_node_get_data(hnode), p); + append_printf(bufp, end, ":%s(%s)", handler, p); /* Compose 'action' parameter */ knode = xbc_node_find_child(hnode, "trace"); @@ -294,6 +295,32 @@ trace_boot_hist_add_handler(struct xbc_node *hnode, char **bufp, return 0; } +static int __init +trace_boot_hist_add_handlers(struct xbc_node *hnode, char **bufp, + char *end, const char *param) +{ + struct xbc_node *node; + const char *p, *handler; + int ret; + + handler = xbc_node_get_data(hnode); + + xbc_node_for_each_subkey(hnode, node) { + p = xbc_node_get_data(node); + if (!isdigit(p[0])) + continue; + /* All digit started node should be instances. */ + ret = trace_boot_hist_add_one_handler(node, bufp, end, handler, param); + if (ret < 0) + break; + } + + if (xbc_node_find_child(hnode, param)) + ret = trace_boot_hist_add_one_handler(hnode, bufp, end, handler, param); + + return ret; +} + /* * Histogram boottime tracing syntax. * @@ -305,8 +332,8 @@ trace_boot_hist_add_handler(struct xbc_node *hnode, char **bufp, * name = * var { = ... } * pause|continue|clear - * onmax|onchange { var = ; [= ] } - * onmatch { event = ; [= ] } + * onmax|onchange[.N] { var = ; [= ] } + * onmatch[.N] { event = ; [= ] } * filter = * } * @@ -368,13 +395,13 @@ trace_boot_compose_hist_cmd(struct xbc_node *hnode, char *buf, size_t size) /* Histogram handler and actions */ node = xbc_node_find_child(hnode, "onmax"); - if (node && trace_boot_hist_add_handler(node, &buf, end, "var") < 0) + if (node && trace_boot_hist_add_handlers(node, &buf, end, "var") < 0) return -EINVAL; node = xbc_node_find_child(hnode, "onchange"); - if (node && trace_boot_hist_add_handler(node, &buf, end, "var") < 0) + if (node && trace_boot_hist_add_handlers(node, &buf, end, "var") < 0) return -EINVAL; node = xbc_node_find_child(hnode, "onmatch"); - if (node && trace_boot_hist_add_handler(node, &buf, end, "event") < 0) + if (node && trace_boot_hist_add_handlers(node, &buf, end, "event") < 0) return -EINVAL; p = xbc_node_find_value(hnode, "filter", NULL); -- cgit v1.2.3 From 17abd7c36c77c393fa65cde462059395d6437dba Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Tue, 10 Aug 2021 11:07:36 +0900 Subject: tracing/boot: Support multiple histograms for each event Add multiple histograms support for each event. This allows user to set multiple histograms to an event. ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist[.N] { ... } The 'N' is a digit started string and it can be omitted for the default histogram. For example, multiple hist triggers example in the Documentation/trace/histogram.rst can be written as below; ftrace.event.net.netif_receive_skb.hist { 1 { keys = skbaddr.hex values = len filter = len < 0 } 2 { keys = skbaddr.hex values = len filter = len > 4096 } 3 { keys = skbaddr.hex values = len filter = len == 256 } 4 { keys = skbaddr.hex values = len } 5 { keys = len values = common_preempt_count } } Link: https://lkml.kernel.org/r/162856125628.203126.15846930277378572120.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_boot.c | 41 ++++++++++++++++++++++++++++++++--------- 1 file changed, 32 insertions(+), 9 deletions(-) (limited to 'kernel/trace/trace_boot.c') diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index f024f27b3602..1a2b270e9cda 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -324,7 +324,7 @@ trace_boot_hist_add_handlers(struct xbc_node *hnode, char **bufp, /* * Histogram boottime tracing syntax. * - * ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist { + * ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist[.N] { * keys = [,...] * values = [,...] * sort = [,...] @@ -415,11 +415,37 @@ trace_boot_compose_hist_cmd(struct xbc_node *hnode, char *buf, size_t size) return 0; } + +static void __init +trace_boot_init_histograms(struct trace_event_file *file, + struct xbc_node *hnode, char *buf, size_t size) +{ + struct xbc_node *node; + const char *p; + + xbc_node_for_each_subkey(hnode, node) { + p = xbc_node_get_data(node); + if (!isdigit(p[0])) + continue; + /* All digit started node should be instances. */ + if (trace_boot_compose_hist_cmd(node, buf, size) == 0) { + if (trigger_process_regex(file, buf) < 0) + pr_err("Failed to apply hist trigger: %s\n", buf); + } + } + + if (xbc_node_find_child(hnode, "keys")) { + if (trace_boot_compose_hist_cmd(hnode, buf, size) == 0) + if (trigger_process_regex(file, buf) < 0) + pr_err("Failed to apply hist trigger: %s\n", buf); + } +} #else -static int __init -trace_boot_compose_hist_cmd(struct xbc_node *hnode, char *buf, size_t size) +static void __init +trace_boot_init_histograms(struct trace_event_file *file, + struct xbc_node *hnode, char *buf, size_t size) { - return -EOPNOTSUPP; + /* do nothing */ } #endif @@ -465,11 +491,8 @@ trace_boot_init_one_event(struct trace_array *tr, struct xbc_node *gnode, pr_err("Failed to apply an action: %s\n", buf); } anode = xbc_node_find_child(enode, "hist"); - if (anode && - trace_boot_compose_hist_cmd(anode, buf, ARRAY_SIZE(buf)) == 0) { - if (trigger_process_regex(file, buf) < 0) - pr_err("Failed to apply hist trigger: %s\n", buf); - } + if (anode) + trace_boot_init_histograms(file, anode, buf, ARRAY_SIZE(buf)); } else if (xbc_node_find_value(enode, "actions", NULL)) pr_err("Failed to apply event actions because CONFIG_HIST_TRIGGERS is not set.\n"); -- cgit v1.2.3 From 64dc7f6958ef56512137ed6ec228127cef7724e9 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Tue, 10 Aug 2021 11:07:44 +0900 Subject: tracing/boot: Show correct histogram error command Since trigger_process_regex() modifies given trigger actions while parsing, the error message couldn't show what command was passed to the trigger_process_regex() when it returns an error. To fix that, show the backed up trigger action command instead of parsed buffer. Link: https://lkml.kernel.org/r/162856126413.203126.9465564928450701424.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_boot.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) (limited to 'kernel/trace/trace_boot.c') diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index 1a2b270e9cda..1060b0446032 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -422,6 +422,7 @@ trace_boot_init_histograms(struct trace_event_file *file, { struct xbc_node *node; const char *p; + char *tmp; xbc_node_for_each_subkey(hnode, node) { p = xbc_node_get_data(node); @@ -429,15 +430,20 @@ trace_boot_init_histograms(struct trace_event_file *file, continue; /* All digit started node should be instances. */ if (trace_boot_compose_hist_cmd(node, buf, size) == 0) { + tmp = kstrdup(buf, GFP_KERNEL); if (trigger_process_regex(file, buf) < 0) - pr_err("Failed to apply hist trigger: %s\n", buf); + pr_err("Failed to apply hist trigger: %s\n", tmp); + kfree(tmp); } } if (xbc_node_find_child(hnode, "keys")) { - if (trace_boot_compose_hist_cmd(hnode, buf, size) == 0) + if (trace_boot_compose_hist_cmd(hnode, buf, size) == 0) { + tmp = kstrdup(buf, GFP_KERNEL); if (trigger_process_regex(file, buf) < 0) - pr_err("Failed to apply hist trigger: %s\n", buf); + pr_err("Failed to apply hist trigger: %s\n", tmp); + kfree(tmp); + } } } #else @@ -488,7 +494,7 @@ trace_boot_init_one_event(struct trace_array *tr, struct xbc_node *gnode, if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) pr_err("action string is too long: %s\n", p); else if (trigger_process_regex(file, buf) < 0) - pr_err("Failed to apply an action: %s\n", buf); + pr_err("Failed to apply an action: %s\n", p); } anode = xbc_node_find_child(enode, "hist"); if (anode) -- cgit v1.2.3 From cfd799837dbc48499abb05d1891b3d9992354d3a Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 9 Sep 2021 04:38:03 +0900 Subject: tracing/boot: Fix to loop on only subkeys Since the commit e5efaeb8a8f5 ("bootconfig: Support mixing a value and subkeys under a key") allows to co-exist a value node and key nodes under a node, xbc_node_for_each_child() is not only returning key node but also a value node. In the boot-time tracing using xbc_node_for_each_child() to iterate the events, groups and instances, but those must be key nodes. Thus it must use xbc_node_for_each_subkey(). Link: https://lkml.kernel.org/r/163112988361.74896.2267026262061819145.stgit@devnote2 Fixes: e5efaeb8a8f5 ("bootconfig: Support mixing a value and subkeys under a key") Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_boot.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel/trace/trace_boot.c') diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index 1060b0446032..388e65d05978 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -522,14 +522,14 @@ trace_boot_init_events(struct trace_array *tr, struct xbc_node *node) if (!node) return; /* per-event key starts with "event.GROUP.EVENT" */ - xbc_node_for_each_child(node, gnode) { + xbc_node_for_each_subkey(node, gnode) { data = xbc_node_get_data(gnode); if (!strcmp(data, "enable")) { enable_all = true; continue; } enable = false; - xbc_node_for_each_child(gnode, enode) { + xbc_node_for_each_subkey(gnode, enode) { data = xbc_node_get_data(enode); if (!strcmp(data, "enable")) { enable = true; @@ -625,7 +625,7 @@ trace_boot_init_instances(struct xbc_node *node) if (!node) return; - xbc_node_for_each_child(node, inode) { + xbc_node_for_each_subkey(node, inode) { p = xbc_node_get_data(inode); if (!p || *p == '\0') continue; -- cgit v1.2.3 From a3928f877e7b153dbc243d6329b3777ac75b6004 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 9 Sep 2021 22:36:23 +0900 Subject: tracing/boot: Fix trace_boot_hist_add_array() to check array is value trace_boot_hist_add_array() uses the combination of xbc_node_find_child() and xbc_node_get_child() to get the child node of the key node. But since it missed to check the child node is data node or not, user can pass the subkey node for the array node (anode). To avoid this issue, check the array node is a data node. Actually, there is xbc_node_find_value(node, key, vnode), which ensures the @vnode is a value node, so use it in trace_boot_hist_add_array() to fix this issue. Link: https://lkml.kernel.org/r/163119458308.161018.1516455973625940212.stgit@devnote2 Fixes: e66ed86ca6c5 ("tracing/boot: Add per-event histogram action options") Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_boot.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'kernel/trace/trace_boot.c') diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index 388e65d05978..a6be48b24774 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -219,13 +219,12 @@ static int __init trace_boot_hist_add_array(struct xbc_node *hnode, char **bufp, char *end, const char *key) { - struct xbc_node *knode, *anode; + struct xbc_node *anode; const char *p; char sep; - knode = xbc_node_find_child(hnode, key); - if (knode) { - anode = xbc_node_get_child(knode); + p = xbc_node_find_value(hnode, key, &anode); + if (p) { if (!anode) { pr_err("hist.%s requires value(s).\n", key); return -EINVAL; -- cgit v1.2.3 From 5f8895b27da2656e5e2be029acfb68c016f03326 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 9 Sep 2021 22:36:30 +0900 Subject: tracing/boot: Fix to check the histogram control param is a leaf node Since xbc_node_find_child() doesn't ensure the returned node is a leaf node (key-value pair or do not have subkeys), use xbc_node_find_value to ensure the histogram control parameter is a leaf node in trace_boot_compose_hist_cmd(). Link: https://lkml.kernel.org/r/163119459059.161018.18341288218424528962.stgit@devnote2 Fixes: e66ed86ca6c5 ("tracing/boot: Add per-event histogram action options") Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_boot.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel/trace/trace_boot.c') diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index a6be48b24774..db6ee372dc6d 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -385,11 +385,11 @@ trace_boot_compose_hist_cmd(struct xbc_node *hnode, char *buf, size_t size) } /* Histogram control attributes (mutual exclusive) */ - if (xbc_node_find_child(hnode, "pause")) + if (xbc_node_find_value(hnode, "pause", NULL)) append_printf(&buf, end, ":pause"); - else if (xbc_node_find_child(hnode, "continue")) + else if (xbc_node_find_value(hnode, "continue", NULL)) append_printf(&buf, end, ":continue"); - else if (xbc_node_find_child(hnode, "clear")) + else if (xbc_node_find_value(hnode, "clear", NULL)) append_printf(&buf, end, ":clear"); /* Histogram handler and actions */ -- cgit v1.2.3 From 5dfe50b05588010f347cb2f436434bf22b7a84ed Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 9 Sep 2021 22:36:38 +0900 Subject: bootconfig: Rename xbc_node_find_child() to xbc_node_find_subkey() Rename xbc_node_find_child() to xbc_node_find_subkey() for clarifying that function returns a key node (no value node). Since there are xbc_node_for_each_child() (loop on all child nodes) and xbc_node_for_each_subkey() (loop on only subkey nodes), this name distinction is necessary to avoid confusing users. Link: https://lkml.kernel.org/r/163119459826.161018.11200274779483115300.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_boot.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) (limited to 'kernel/trace/trace_boot.c') diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index db6ee372dc6d..8d252f63cd78 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -262,9 +262,9 @@ trace_boot_hist_add_one_handler(struct xbc_node *hnode, char **bufp, append_printf(bufp, end, ":%s(%s)", handler, p); /* Compose 'action' parameter */ - knode = xbc_node_find_child(hnode, "trace"); + knode = xbc_node_find_subkey(hnode, "trace"); if (!knode) - knode = xbc_node_find_child(hnode, "save"); + knode = xbc_node_find_subkey(hnode, "save"); if (knode) { anode = xbc_node_get_child(knode); @@ -283,7 +283,7 @@ trace_boot_hist_add_one_handler(struct xbc_node *hnode, char **bufp, sep = ','; } append_printf(bufp, end, ")"); - } else if (xbc_node_find_child(hnode, "snapshot")) { + } else if (xbc_node_find_subkey(hnode, "snapshot")) { append_printf(bufp, end, ".snapshot()"); } else { pr_err("hist.%s requires an action.\n", @@ -314,7 +314,7 @@ trace_boot_hist_add_handlers(struct xbc_node *hnode, char **bufp, break; } - if (xbc_node_find_child(hnode, param)) + if (xbc_node_find_subkey(hnode, param)) ret = trace_boot_hist_add_one_handler(hnode, bufp, end, handler, param); return ret; @@ -374,7 +374,7 @@ trace_boot_compose_hist_cmd(struct xbc_node *hnode, char *buf, size_t size) if (p) append_printf(&buf, end, ":name=%s", p); - node = xbc_node_find_child(hnode, "var"); + node = xbc_node_find_subkey(hnode, "var"); if (node) { xbc_node_for_each_key_value(node, knode, p) { /* Expression must not include spaces. */ @@ -393,13 +393,13 @@ trace_boot_compose_hist_cmd(struct xbc_node *hnode, char *buf, size_t size) append_printf(&buf, end, ":clear"); /* Histogram handler and actions */ - node = xbc_node_find_child(hnode, "onmax"); + node = xbc_node_find_subkey(hnode, "onmax"); if (node && trace_boot_hist_add_handlers(node, &buf, end, "var") < 0) return -EINVAL; - node = xbc_node_find_child(hnode, "onchange"); + node = xbc_node_find_subkey(hnode, "onchange"); if (node && trace_boot_hist_add_handlers(node, &buf, end, "var") < 0) return -EINVAL; - node = xbc_node_find_child(hnode, "onmatch"); + node = xbc_node_find_subkey(hnode, "onmatch"); if (node && trace_boot_hist_add_handlers(node, &buf, end, "event") < 0) return -EINVAL; @@ -436,7 +436,7 @@ trace_boot_init_histograms(struct trace_event_file *file, } } - if (xbc_node_find_child(hnode, "keys")) { + if (xbc_node_find_subkey(hnode, "keys")) { if (trace_boot_compose_hist_cmd(hnode, buf, size) == 0) { tmp = kstrdup(buf, GFP_KERNEL); if (trigger_process_regex(file, buf) < 0) @@ -495,7 +495,7 @@ trace_boot_init_one_event(struct trace_array *tr, struct xbc_node *gnode, else if (trigger_process_regex(file, buf) < 0) pr_err("Failed to apply an action: %s\n", p); } - anode = xbc_node_find_child(enode, "hist"); + anode = xbc_node_find_subkey(enode, "hist"); if (anode) trace_boot_init_histograms(file, anode, buf, ARRAY_SIZE(buf)); } else if (xbc_node_find_value(enode, "actions", NULL)) @@ -517,7 +517,7 @@ trace_boot_init_events(struct trace_array *tr, struct xbc_node *node) bool enable, enable_all = false; const char *data; - node = xbc_node_find_child(node, "event"); + node = xbc_node_find_subkey(node, "event"); if (!node) return; /* per-event key starts with "event.GROUP.EVENT" */ @@ -620,7 +620,7 @@ trace_boot_init_instances(struct xbc_node *node) struct trace_array *tr; const char *p; - node = xbc_node_find_child(node, "instance"); + node = xbc_node_find_subkey(node, "instance"); if (!node) return; -- cgit v1.2.3