From d8a64313c171464aedd6289378a51c8f0f524acb Mon Sep 17 00:00:00 2001 From: Lukas Bulwahn Date: Thu, 11 Aug 2022 09:17:34 +0200 Subject: tracing: React to error return from traceprobe_parse_event_name() The function traceprobe_parse_event_name() may set the first two function arguments to a non-null value and still return -EINVAL to indicate an unsuccessful completion of the function. Hence, it is not sufficient to just check the result of the two function arguments for being not null, but the return value also needs to be checked. Commit 95c104c378dc ("tracing: Auto generate event name when creating a group of events") changed the error-return-value checking of the second traceprobe_parse_event_name() invocation in __trace_eprobe_create() and removed checking the return value to jump to the error handling case. Reinstate using the return value in the error-return-value checking. Link: https://lkml.kernel.org/r/20220811071734.20700-1-lukas.bulwahn@gmail.com Fixes: 95c104c378dc ("tracing: Auto generate event name when creating a group of events") Acked-by: Linyu Yuan Signed-off-by: Lukas Bulwahn Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_eprobe.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c index 4a0e9d927443..550671985fd1 100644 --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -883,7 +883,7 @@ static int __trace_eprobe_create(int argc, const char *argv[]) trace_probe_log_set_index(1); sys_event = argv[1]; ret = traceprobe_parse_event_name(&sys_event, &sys_name, buf2, 0); - if (!sys_event || !sys_name) { + if (ret || !sys_event || !sys_name) { trace_probe_log_err(0, NO_EVENT_INFO); goto parse_error; } -- cgit v1.2.3-58-ga151 From 7249921d94ff64f67b733eca0b68853a62032b3d Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" Date: Tue, 16 Aug 2022 19:28:17 -0400 Subject: tracing/perf: Fix double put of trace event when init fails If in perf_trace_event_init(), the perf_trace_event_open() fails, then it will call perf_trace_event_unreg() which will not only unregister the perf trace event, but will also call the put() function of the tp_event. The problem here is that the trace_event_try_get_ref() is called by the caller of perf_trace_event_init() and if perf_trace_event_init() returns a failure, it will then call trace_event_put(). But since the perf_trace_event_unreg() already called the trace_event_put() function, it triggers a WARN_ON(). WARNING: CPU: 1 PID: 30309 at kernel/trace/trace_dynevent.c:46 trace_event_dyn_put_ref+0x15/0x20 If perf_trace_event_reg() does not call the trace_event_try_get_ref() then the perf_trace_event_unreg() should not be calling trace_event_put(). This breaks symmetry and causes bugs like these. Pull out the trace_event_put() from perf_trace_event_unreg() and call it in the locations that perf_trace_event_unreg() is called. This not only fixes this bug, but also brings back the proper symmetry of the reg/unreg vs get/put logic. Link: https://lore.kernel.org/all/cover.1660347763.git.kjlx@templeofstupid.com/ Link: https://lkml.kernel.org/r/20220816192817.43d5e17f@gandalf.local.home Cc: stable@vger.kernel.org Fixes: 1d18538e6a092 ("tracing: Have dynamic events have a ref counter") Reported-by: Krister Johansen Reviewed-by: Krister Johansen Tested-by: Krister Johansen Acked-by: Jiri Olsa Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_event_perf.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index a114549720d6..61e3a2620fa3 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -157,7 +157,7 @@ static void perf_trace_event_unreg(struct perf_event *p_event) int i; if (--tp_event->perf_refcount > 0) - goto out; + return; tp_event->class->reg(tp_event, TRACE_REG_PERF_UNREGISTER, NULL); @@ -176,8 +176,6 @@ static void perf_trace_event_unreg(struct perf_event *p_event) perf_trace_buf[i] = NULL; } } -out: - trace_event_put_ref(tp_event); } static int perf_trace_event_open(struct perf_event *p_event) @@ -241,6 +239,7 @@ void perf_trace_destroy(struct perf_event *p_event) mutex_lock(&event_mutex); perf_trace_event_close(p_event); perf_trace_event_unreg(p_event); + trace_event_put_ref(p_event->tp_event); mutex_unlock(&event_mutex); } @@ -292,6 +291,7 @@ void perf_kprobe_destroy(struct perf_event *p_event) mutex_lock(&event_mutex); perf_trace_event_close(p_event); perf_trace_event_unreg(p_event); + trace_event_put_ref(p_event->tp_event); mutex_unlock(&event_mutex); destroy_local_trace_kprobe(p_event->tp_event); @@ -347,6 +347,7 @@ void perf_uprobe_destroy(struct perf_event *p_event) mutex_lock(&event_mutex); perf_trace_event_close(p_event); perf_trace_event_unreg(p_event); + trace_event_put_ref(p_event->tp_event); mutex_unlock(&event_mutex); destroy_local_trace_uprobe(p_event->tp_event); } -- cgit v1.2.3-58-ga151 From c3b0f72e805f0801f05fa2aa52011c4bfc694c44 Mon Sep 17 00:00:00 2001 From: Yang Jihong Date: Thu, 18 Aug 2022 11:26:59 +0800 Subject: ftrace: Fix NULL pointer dereference in is_ftrace_trampoline when ftrace is dead ftrace_startup does not remove ops from ftrace_ops_list when ftrace_startup_enable fails: register_ftrace_function ftrace_startup __register_ftrace_function ... add_ftrace_ops(&ftrace_ops_list, ops) ... ... ftrace_startup_enable // if ftrace failed to modify, ftrace_disabled is set to 1 ... return 0 // ops is in the ftrace_ops_list. When ftrace_disabled = 1, unregister_ftrace_function simply returns without doing anything: unregister_ftrace_function ftrace_shutdown if (unlikely(ftrace_disabled)) return -ENODEV; // return here, __unregister_ftrace_function is not executed, // as a result, ops is still in the ftrace_ops_list __unregister_ftrace_function ... If ops is dynamically allocated, it will be free later, in this case, is_ftrace_trampoline accesses NULL pointer: is_ftrace_trampoline ftrace_ops_trampoline do_for_each_ftrace_op(op, ftrace_ops_list) // OOPS! op may be NULL! Syzkaller reports as follows: [ 1203.506103] BUG: kernel NULL pointer dereference, address: 000000000000010b [ 1203.508039] #PF: supervisor read access in kernel mode [ 1203.508798] #PF: error_code(0x0000) - not-present page [ 1203.509558] PGD 800000011660b067 P4D 800000011660b067 PUD 130fb8067 PMD 0 [ 1203.510560] Oops: 0000 [#1] SMP KASAN PTI [ 1203.511189] CPU: 6 PID: 29532 Comm: syz-executor.2 Tainted: G B W 5.10.0 #8 [ 1203.512324] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 1203.513895] RIP: 0010:is_ftrace_trampoline+0x26/0xb0 [ 1203.514644] Code: ff eb d3 90 41 55 41 54 49 89 fc 55 53 e8 f2 00 fd ff 48 8b 1d 3b 35 5d 03 e8 e6 00 fd ff 48 8d bb 90 00 00 00 e8 2a 81 26 00 <48> 8b ab 90 00 00 00 48 85 ed 74 1d e8 c9 00 fd ff 48 8d bb 98 00 [ 1203.518838] RSP: 0018:ffffc900012cf960 EFLAGS: 00010246 [ 1203.520092] RAX: 0000000000000000 RBX: 000000000000007b RCX: ffffffff8a331866 [ 1203.521469] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 000000000000010b [ 1203.522583] RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8df18b07 [ 1203.523550] R10: fffffbfff1be3160 R11: 0000000000000001 R12: 0000000000478399 [ 1203.524596] R13: 0000000000000000 R14: ffff888145088000 R15: 0000000000000008 [ 1203.525634] FS: 00007f429f5f4700(0000) GS:ffff8881daf00000(0000) knlGS:0000000000000000 [ 1203.526801] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1203.527626] CR2: 000000000000010b CR3: 0000000170e1e001 CR4: 00000000003706e0 [ 1203.528611] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 1203.529605] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Therefore, when ftrace_startup_enable fails, we need to rollback registration process and remove ops from ftrace_ops_list. Link: https://lkml.kernel.org/r/20220818032659.56209-1-yangjihong1@huawei.com Suggested-by: Steven Rostedt Signed-off-by: Yang Jihong Signed-off-by: Steven Rostedt (Google) --- kernel/trace/ftrace.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 601ccf1b2f09..4baa99363b16 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2937,6 +2937,16 @@ int ftrace_startup(struct ftrace_ops *ops, int command) ftrace_startup_enable(command); + /* + * If ftrace is in an undefined state, we just remove ops from list + * to prevent the NULL pointer, instead of totally rolling it back and + * free trampoline, because those actions could cause further damage. + */ + if (unlikely(ftrace_disabled)) { + __unregister_ftrace_function(ops); + return -ENODEV; + } + ops->flags &= ~FTRACE_OPS_FL_ADDING; return 0; -- cgit v1.2.3-58-ga151 From 2673c60ee67e71f2ebe34386e62d348f71edee47 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" Date: Sat, 20 Aug 2022 09:43:17 -0400 Subject: tracing/eprobes: Do not allow eprobes to use $stack, or % for regs While playing with event probes (eprobes), I tried to see what would happen if I attempted to retrieve the instruction pointer (%rip) knowing that event probes do not use pt_regs. The result was: BUG: kernel NULL pointer dereference, address: 0000000000000024 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 1 PID: 1847 Comm: trace-cmd Not tainted 5.19.0-rc5-test+ #309 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016 RIP: 0010:get_event_field.isra.0+0x0/0x50 Code: ff 48 c7 c7 c0 8f 74 a1 e8 3d 8b f5 ff e8 88 09 f6 ff 4c 89 e7 e8 50 6a 13 00 48 89 ef 5b 5d 41 5c 41 5d e9 42 6a 13 00 66 90 <48> 63 47 24 8b 57 2c 48 01 c6 8b 47 28 83 f8 02 74 0e 83 f8 04 74 RSP: 0018:ffff916c394bbaf0 EFLAGS: 00010086 RAX: ffff916c854041d8 RBX: ffff916c8d9fbf50 RCX: ffff916c255d2000 RDX: 0000000000000000 RSI: ffff916c255d2008 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffff916c3a2a0c08 R09: ffff916c394bbda8 R10: 0000000000000000 R11: 0000000000000000 R12: ffff916c854041d8 R13: ffff916c854041b0 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff916c9ea40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000024 CR3: 000000011b60a002 CR4: 00000000001706e0 Call Trace: get_eprobe_size+0xb4/0x640 ? __mod_node_page_state+0x72/0xc0 __eprobe_trace_func+0x59/0x1a0 ? __mod_lruvec_page_state+0xaa/0x1b0 ? page_remove_file_rmap+0x14/0x230 ? page_remove_rmap+0xda/0x170 event_triggers_call+0x52/0xe0 trace_event_buffer_commit+0x18f/0x240 trace_event_raw_event_sched_wakeup_template+0x7a/0xb0 try_to_wake_up+0x260/0x4c0 __wake_up_common+0x80/0x180 __wake_up_common_lock+0x7c/0xc0 do_notify_parent+0x1c9/0x2a0 exit_notify+0x1a9/0x220 do_exit+0x2ba/0x450 do_group_exit+0x2d/0x90 __x64_sys_exit_group+0x14/0x20 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Obviously this is not the desired result. Move the testing for TPARG_FL_TPOINT which is only used for event probes to the top of the "$" variable check, as all the other variables are not used for event probes. Also add a check in the register parsing "%" to fail if an event probe is used. Link: https://lkml.kernel.org/r/20220820134400.564426983@goodmis.org Cc: stable@vger.kernel.org Cc: Ingo Molnar Cc: Andrew Morton Cc: Tzvetomir Stoyanov Cc: Tom Zanussi Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events") Acked-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_probe.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 850a88abd33b..dec657af363c 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -283,7 +283,14 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, int ret = 0; int len; - if (strcmp(arg, "retval") == 0) { + if (flags & TPARG_FL_TPOINT) { + if (code->data) + return -EFAULT; + code->data = kstrdup(arg, GFP_KERNEL); + if (!code->data) + return -ENOMEM; + code->op = FETCH_OP_TP_ARG; + } else if (strcmp(arg, "retval") == 0) { if (flags & TPARG_FL_RETURN) { code->op = FETCH_OP_RETVAL; } else { @@ -323,13 +330,6 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, code->op = FETCH_OP_ARG; code->param = (unsigned int)param - 1; #endif - } else if (flags & TPARG_FL_TPOINT) { - if (code->data) - return -EFAULT; - code->data = kstrdup(arg, GFP_KERNEL); - if (!code->data) - return -ENOMEM; - code->op = FETCH_OP_TP_ARG; } else goto inval_var; @@ -384,6 +384,11 @@ parse_probe_arg(char *arg, const struct fetch_type *type, break; case '%': /* named register */ + if (flags & TPARG_FL_TPOINT) { + /* eprobes do not handle registers */ + trace_probe_log_err(offs, BAD_VAR); + break; + } ret = regs_query_register_offset(arg + 1); if (ret >= 0) { code->op = FETCH_OP_REG; -- cgit v1.2.3-58-ga151 From 02333de90e5945e2fe7fc75b15b4eb9aee187f0a Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" Date: Sat, 20 Aug 2022 09:43:18 -0400 Subject: tracing/eprobes: Do not hardcode $comm as a string The variable $comm is hard coded as a string, which is true for both kprobes and uprobes, but for event probes (eprobes) it is a field name. In most cases the "comm" field would be a string, but there's no guarantee of that fact. Do not assume that comm is a string. Not to mention, it currently forces comm fields to fault, as string processing for event probes is currently broken. Link: https://lkml.kernel.org/r/20220820134400.756152112@goodmis.org Cc: stable@vger.kernel.org Cc: Ingo Molnar Cc: Andrew Morton Cc: Masami Hiramatsu Cc: Tzvetomir Stoyanov Cc: Tom Zanussi Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events") Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_probe.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index dec657af363c..4daabbb8b772 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -622,9 +622,10 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size, /* * Since $comm and immediate string can not be dereferenced, - * we can find those by strcmp. + * we can find those by strcmp. But ignore for eprobes. */ - if (strcmp(arg, "$comm") == 0 || strncmp(arg, "\\\"", 2) == 0) { + if (!(flags & TPARG_FL_TPOINT) && + (strcmp(arg, "$comm") == 0 || strncmp(arg, "\\\"", 2) == 0)) { /* The type of $comm must be "string", and not an array. */ if (parg->count || (t && strcmp(t, "string"))) goto out; -- cgit v1.2.3-58-ga151 From f04dec93466a0481763f3b56cdadf8076e28bfbf Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" Date: Sat, 20 Aug 2022 09:43:19 -0400 Subject: tracing/eprobes: Fix reading of string fields Currently when an event probe (eprobe) hooks to a string field, it does not display it as a string, but instead as a number. This makes the field rather useless. Handle the different kinds of strings, dynamic, static, relational/dynamic etc. Now when a string field is used, the ":string" type can be used to display it: echo "e:sw sched/sched_switch comm=$next_comm:string" > dynamic_events Link: https://lkml.kernel.org/r/20220820134400.959640191@goodmis.org Cc: stable@vger.kernel.org Cc: Ingo Molnar Cc: Andrew Morton Cc: Tzvetomir Stoyanov Cc: Tom Zanussi Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events") Acked-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_eprobe.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c index 550671985fd1..a1d3423ab74f 100644 --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -311,6 +311,27 @@ static unsigned long get_event_field(struct fetch_insn *code, void *rec) addr = rec + field->offset; + if (is_string_field(field)) { + switch (field->filter_type) { + case FILTER_DYN_STRING: + val = (unsigned long)(rec + (*(unsigned int *)addr & 0xffff)); + break; + case FILTER_RDYN_STRING: + val = (unsigned long)(addr + (*(unsigned int *)addr & 0xffff)); + break; + case FILTER_STATIC_STRING: + val = (unsigned long)addr; + break; + case FILTER_PTR_STRING: + val = (unsigned long)(*(char *)addr); + break; + default: + WARN_ON_ONCE(1); + return 0; + } + return val; + } + switch (field->size) { case 1: if (field->is_signed) -- cgit v1.2.3-58-ga151 From 6a832ec3d680b3a4f4fad5752672827d71bae501 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" Date: Sat, 20 Aug 2022 09:43:20 -0400 Subject: tracing/eprobes: Have event probes be consistent with kprobes and uprobes Currently, if a symbol "@" is attempted to be used with an event probe (eprobes), it will cause a NULL pointer dereference crash. Both kprobes and uprobes can reference data other than the main registers. Such as immediate address, symbols and the current task name. Have eprobes do the same thing. For "comm", if "comm" is used and the event being attached to does not have the "comm" field, then make it the "$comm" that kprobes has. This is consistent to the way histograms and filters work. Link: https://lkml.kernel.org/r/20220820134401.136924220@goodmis.org Cc: stable@vger.kernel.org Cc: Ingo Molnar Cc: Andrew Morton Cc: Masami Hiramatsu Cc: Tzvetomir Stoyanov Cc: Tom Zanussi Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events") Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_eprobe.c | 70 +++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 64 insertions(+), 6 deletions(-) diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c index a1d3423ab74f..1783e3478912 100644 --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -227,6 +227,7 @@ static int trace_eprobe_tp_arg_update(struct trace_eprobe *ep, int i) struct probe_arg *parg = &ep->tp.args[i]; struct ftrace_event_field *field; struct list_head *head; + int ret = -ENOENT; head = trace_get_fields(ep->event); list_for_each_entry(field, head, link) { @@ -236,9 +237,20 @@ static int trace_eprobe_tp_arg_update(struct trace_eprobe *ep, int i) return 0; } } + + /* + * Argument not found on event. But allow for comm and COMM + * to be used to get the current->comm. + */ + if (strcmp(parg->code->data, "COMM") == 0 || + strcmp(parg->code->data, "comm") == 0) { + parg->code->op = FETCH_OP_COMM; + ret = 0; + } + kfree(parg->code->data); parg->code->data = NULL; - return -ENOENT; + return ret; } static int eprobe_event_define_fields(struct trace_event_call *event_call) @@ -363,16 +375,38 @@ static unsigned long get_event_field(struct fetch_insn *code, void *rec) static int get_eprobe_size(struct trace_probe *tp, void *rec) { + struct fetch_insn *code; struct probe_arg *arg; int i, len, ret = 0; for (i = 0; i < tp->nr_args; i++) { arg = tp->args + i; - if (unlikely(arg->dynamic)) { + if (arg->dynamic) { unsigned long val; - val = get_event_field(arg->code, rec); - len = process_fetch_insn_bottom(arg->code + 1, val, NULL, NULL); + code = arg->code; + retry: + switch (code->op) { + case FETCH_OP_TP_ARG: + val = get_event_field(code, rec); + break; + case FETCH_OP_IMM: + val = code->immediate; + break; + case FETCH_OP_COMM: + val = (unsigned long)current->comm; + break; + case FETCH_OP_DATA: + val = (unsigned long)code->data; + break; + case FETCH_NOP_SYMBOL: /* Ignore a place holder */ + code++; + goto retry; + default: + continue; + } + code++; + len = process_fetch_insn_bottom(code, val, NULL, NULL); if (len > 0) ret += len; } @@ -390,8 +424,28 @@ process_fetch_insn(struct fetch_insn *code, void *rec, void *dest, { unsigned long val; - val = get_event_field(code, rec); - return process_fetch_insn_bottom(code + 1, val, dest, base); + retry: + switch (code->op) { + case FETCH_OP_TP_ARG: + val = get_event_field(code, rec); + break; + case FETCH_OP_IMM: + val = code->immediate; + break; + case FETCH_OP_COMM: + val = (unsigned long)current->comm; + break; + case FETCH_OP_DATA: + val = (unsigned long)code->data; + break; + case FETCH_NOP_SYMBOL: /* Ignore a place holder */ + code++; + goto retry; + default: + return -EILSEQ; + } + code++; + return process_fetch_insn_bottom(code, val, dest, base); } NOKPROBE_SYMBOL(process_fetch_insn) @@ -866,6 +920,10 @@ static int trace_eprobe_tp_update_arg(struct trace_eprobe *ep, const char *argv[ trace_probe_log_err(0, BAD_ATTACH_ARG); } + /* Handle symbols "@" */ + if (!ret) + ret = traceprobe_update_arg(&ep->tp.args[i]); + return ret; } -- cgit v1.2.3-58-ga151 From ab8384442ee512fc0fc72deeb036110843d0e7ff Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" Date: Sat, 20 Aug 2022 09:43:21 -0400 Subject: tracing/probes: Have kprobes and uprobes use $COMM too Both $comm and $COMM can be used to get current->comm in eprobes and the filtering and histogram logic. Make kprobes and uprobes consistent in this regard and allow both $comm and $COMM as well. Currently kprobes and uprobes only handle $comm, which is inconsistent with the other utilities, and can be confusing to users. Link: https://lkml.kernel.org/r/20220820134401.317014913@goodmis.org Link: https://lore.kernel.org/all/20220820220442.776e1ddaf8836e82edb34d01@kernel.org/ Cc: stable@vger.kernel.org Cc: Ingo Molnar Cc: Andrew Morton Cc: Tzvetomir Stoyanov Cc: Tom Zanussi Fixes: 533059281ee5 ("tracing: probeevent: Introduce new argument fetching code") Suggested-by: Masami Hiramatsu (Google) Acked-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_probe.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 4daabbb8b772..36dff277de46 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -314,7 +314,7 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, } } else goto inval_var; - } else if (strcmp(arg, "comm") == 0) { + } else if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) { code->op = FETCH_OP_COMM; #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API } else if (((flags & TPARG_FL_MASK) == @@ -625,7 +625,8 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size, * we can find those by strcmp. But ignore for eprobes. */ if (!(flags & TPARG_FL_TPOINT) && - (strcmp(arg, "$comm") == 0 || strncmp(arg, "\\\"", 2) == 0)) { + (strcmp(arg, "$comm") == 0 || strcmp(arg, "$COMM") == 0 || + strncmp(arg, "\\\"", 2) == 0)) { /* The type of $comm must be "string", and not an array. */ if (parg->count || (t && strcmp(t, "string"))) goto out; -- cgit v1.2.3-58-ga151 From b2380577d4fe1c0ef3fa50417f1e441c016e4cbe Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" Date: Sat, 20 Aug 2022 09:43:22 -0400 Subject: tracing: Have filter accept "common_cpu" to be consistent Make filtering consistent with histograms. As "cpu" can be a field of an event, allow for "common_cpu" to keep it from being confused with the "cpu" field of the event. Link: https://lkml.kernel.org/r/20220820134401.513062765@goodmis.org Link: https://lore.kernel.org/all/20220820220920.e42fa32b70505b1904f0a0ad@kernel.org/ Cc: stable@vger.kernel.org Cc: Ingo Molnar Cc: Andrew Morton Cc: Tzvetomir Stoyanov Cc: Tom Zanussi Fixes: 1e3bac71c5053 ("tracing/histogram: Rename "cpu" to "common_cpu"") Suggested-by: Masami Hiramatsu (Google) Acked-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_events.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 181f08186d32..0356cae0cf74 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -176,6 +176,7 @@ static int trace_define_generic_fields(void) __generic_field(int, CPU, FILTER_CPU); __generic_field(int, cpu, FILTER_CPU); + __generic_field(int, common_cpu, FILTER_CPU); __generic_field(char *, COMM, FILTER_COMM); __generic_field(char *, comm, FILTER_COMM); -- cgit v1.2.3-58-ga151