From ba16293dad626d3e3827cfe0a1a743c1d93e76b7 Mon Sep 17 00:00:00 2001 From: Ravi Bangoria Date: Fri, 20 Apr 2018 20:37:58 +0530 Subject: tracing: Fix kernel crash while using empty filter with perf Kernel is crashing when user tries to record 'ftrace:function' event with empty filter: # perf record -e ftrace:function --filter="" ls # dmesg BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 Oops: 0000 [#1] SMP PTI ... RIP: 0010:ftrace_profile_set_filter+0x14b/0x2d0 RSP: 0018:ffffa4a7c0da7d20 EFLAGS: 00010246 RAX: ffffa4a7c0da7d64 RBX: 0000000000000000 RCX: 0000000000000006 RDX: 0000000000000000 RSI: 0000000000000092 RDI: ffff8c48ffc968f0 ... Call Trace: _perf_ioctl+0x54a/0x6b0 ? rcu_all_qs+0x5/0x30 ... After patch: # perf record -e ftrace:function --filter="" ls failed to set filter "" on event ftrace:function with 22 (Invalid argument) Also, if user tries to echo "" > filter, it used to throw an error. This behavior got changed by commit 80765597bc58 ("tracing: Rewrite filter logic to be simpler and faster"). This patch restores the behavior as a side effect: Before patch: # echo "" > filter # After patch: # echo "" > filter bash: echo: write error: Invalid argument # Link: http://lkml.kernel.org/r/20180420150758.19787-1-ravi.bangoria@linux.ibm.com Fixes: 80765597bc58 ("tracing: Rewrite filter logic to be simpler and faster") Signed-off-by: Ravi Bangoria Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_events_filter.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index 9b4716bb8bb0..1f951b3df60c 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -1499,14 +1499,14 @@ static int process_preds(struct trace_event_call *call, return ret; } - if (!nr_preds) { - prog = NULL; - } else { - prog = predicate_parse(filter_string, nr_parens, nr_preds, + if (!nr_preds) + return -EINVAL; + + prog = predicate_parse(filter_string, nr_parens, nr_preds, parse_pred, call, pe); - if (IS_ERR(prog)) - return PTR_ERR(prog); - } + if (IS_ERR(prog)) + return PTR_ERR(prog); + rcu_assign_pointer(filter->prog, prog); return 0; } -- cgit v1.2.3-59-g8ed1b From bcbd385b61bbdef3491d662203ac2e8186e5be59 Mon Sep 17 00:00:00 2001 From: Thomas Richter Date: Thu, 19 Apr 2018 12:55:56 +0200 Subject: kprobes: Fix random address output of blacklist file File /sys/kernel/debug/kprobes/blacklist displays random addresses: [root@s8360046 linux]# cat /sys/kernel/debug/kprobes/blacklist 0x0000000047149a90-0x00000000bfcb099a print_type_x8 .... This breaks 'perf probe' which uses the blacklist file to prohibit probes on certain functions by checking the address range. Fix this by printing the correct (unhashed) address. The file mode is read all but this is not an issue as the file hierarchy points out: # ls -ld /sys/ /sys/kernel/ /sys/kernel/debug/ /sys/kernel/debug/kprobes/ /sys/kernel/debug/kprobes/blacklist dr-xr-xr-x 12 root root 0 Apr 19 07:56 /sys/ drwxr-xr-x 8 root root 0 Apr 19 07:56 /sys/kernel/ drwx------ 16 root root 0 Apr 19 06:56 /sys/kernel/debug/ drwxr-xr-x 2 root root 0 Apr 19 06:56 /sys/kernel/debug/kprobes/ -r--r--r-- 1 root root 0 Apr 19 06:56 /sys/kernel/debug/kprobes/blacklist Everything in and below /sys/kernel/debug is rwx to root only, no group or others have access. Background: Directory /sys/kernel/debug/kprobes is created by debugfs_create_dir() which sets the mode bits to rwxr-xr-x. Maybe change that to use the parent's directory mode bits instead? Link: http://lkml.kernel.org/r/20180419105556.86664-1-tmricht@linux.ibm.com Fixes: ad67b74d2469 ("printk: hash addresses printed with %p") Cc: stable@vger.kernel.org Cc: # v4.15+ Cc: Ananth N Mavinakayanahalli Cc: Anil S Keshavamurthy Cc: David S Miller Cc: Masami Hiramatsu Cc: acme@kernel.org Signed-off-by: Thomas Richter Signed-off-by: Steven Rostedt (VMware) --- kernel/kprobes.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 102160ff5c66..ea619021d901 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -2428,7 +2428,7 @@ static int kprobe_blacklist_seq_show(struct seq_file *m, void *v) struct kprobe_blacklist_entry *ent = list_entry(v, struct kprobe_blacklist_entry, list); - seq_printf(m, "0x%p-0x%p\t%ps\n", (void *)ent->start_addr, + seq_printf(m, "0x%px-0x%px\t%ps\n", (void *)ent->start_addr, (void *)ent->end_addr, (void *)ent->start_addr); return 0; } -- cgit v1.2.3-59-g8ed1b From 9a0fd675304d410f3a9586e1b333e16f4658d56c Mon Sep 17 00:00:00 2001 From: Peter Xu Date: Thu, 15 Mar 2018 14:06:39 +0800 Subject: tracing: Fix missing tab for hwlat_detector print format It's been missing for a while but no one is touching that up. Fix it. Link: http://lkml.kernel.org/r/20180315060639.9578-1-peterx@redhat.com CC: Ingo Molnar Cc:stable@vger.kernel.org Fixes: 7b2c86250122d ("tracing: Add NMI tracing in hwlat detector") Signed-off-by: Peter Xu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_entries.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h index e954ae3d82c0..e3a658bac10f 100644 --- a/kernel/trace/trace_entries.h +++ b/kernel/trace/trace_entries.h @@ -356,7 +356,7 @@ FTRACE_ENTRY(hwlat, hwlat_entry, __field( unsigned int, seqnum ) ), - F_printk("cnt:%u\tts:%010llu.%010lu\tinner:%llu\touter:%llunmi-ts:%llu\tnmi-count:%u\n", + F_printk("cnt:%u\tts:%010llu.%010lu\tinner:%llu\touter:%llu\tnmi-ts:%llu\tnmi-count:%u\n", __entry->seqnum, __entry->tv_sec, __entry->tv_nsec, -- cgit v1.2.3-59-g8ed1b