linux/kernel/trace/trace_probe.c, branch v5.4

tracing/probe: Fix to check the difference of nr_args before adding probe

2019-09-28T21:07:53Z

Steven reported that a test triggered: ================================================================== BUG: KASAN: slab-out-of-bounds in trace_kprobe_create+0xa9e/0xe40 Read of size 8 at addr ffff8880c4f25a48 by task ftracetest/4798 CPU: 2 PID: 4798 Comm: ftracetest Not tainted 5.3.0-rc6-test+ #30 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016 Call Trace: dump_stack+0x7c/0xc0 ? trace_kprobe_create+0xa9e/0xe40 print_address_description+0x6c/0x332 ? trace_kprobe_create+0xa9e/0xe40 ? trace_kprobe_create+0xa9e/0xe40 __kasan_report.cold.6+0x1a/0x3b ? trace_kprobe_create+0xa9e/0xe40 kasan_report+0xe/0x12 trace_kprobe_create+0xa9e/0xe40 ? print_kprobe_event+0x280/0x280 ? match_held_lock+0x1b/0x240 ? find_held_lock+0xac/0xd0 ? fs_reclaim_release.part.112+0x5/0x20 ? lock_downgrade+0x350/0x350 ? kasan_unpoison_shadow+0x30/0x40 ? __kasan_kmalloc.constprop.6+0xc1/0xd0 ? trace_kprobe_create+0xe40/0xe40 ? trace_kprobe_create+0xe40/0xe40 create_or_delete_trace_kprobe+0x2e/0x60 trace_run_command+0xc3/0xe0 ? trace_panic_handler+0x20/0x20 ? kasan_unpoison_shadow+0x30/0x40 trace_parse_run_command+0xdc/0x163 vfs_write+0xe1/0x240 ksys_write+0xba/0x150 ? __ia32_sys_read+0x50/0x50 ? tracer_hardirqs_on+0x61/0x180 ? trace_hardirqs_off_caller+0x43/0x110 ? mark_held_locks+0x29/0xa0 ? do_syscall_64+0x14/0x260 do_syscall_64+0x68/0x260 Fix to check the difference of nr_args before adding probe on existing probes. This also may set the error log index bigger than the number of command parameters. In that case it sets the error position is next to the last parameter. Link: http://lkml.kernel.org/r/156966474783.3478.13217501608215769150.stgit@devnote2 Fixes: ca89bc071d5e ("tracing/kprobe: Add multi-probe per event support") Reported-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

tracing/kprobe: Fix NULL pointer access in trace_porbe_unlink()

2019-09-17T15:21:29Z

Fix NULL pointer access in trace_probe_unlink() by initializing trace_probe.list correctly in trace_probe_init(). In the error case of trace_probe_init(), it can call trace_probe_unlink() before initializing trace_probe.list member. This causes NULL pointer dereference at list_del_init() in trace_probe_unlink(). Syzbot reported : kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 8633 Comm: syz-executor797 Not tainted 5.3.0-rc8-next-20190915 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__list_del_entry_valid+0x85/0xf5 lib/list_debug.c:51 Code: 0f 84 e1 00 00 00 48 b8 22 01 00 00 00 00 ad de 49 39 c4 0f 84 e2 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 75 53 49 8b 14 24 4c 39 f2 0f 85 99 00 00 00 49 8d 7d RSP: 0018:ffff888090a7f9d8 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: ffff88809b6f90c0 RCX: ffffffff817c0ca9 RDX: 0000000000000000 RSI: ffffffff817c0a73 RDI: ffff88809b6f90c8 RBP: ffff888090a7f9f0 R08: ffff88809a04e600 R09: ffffed1015d26aed R10: ffffed1015d26aec R11: ffff8880ae935763 R12: 0000000000000000 R13: 0000000000000000 R14: ffff88809b6f90c0 R15: ffff88809b6f90d0 FS: 0000555556f99880(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000006cc090 CR3: 00000000962b2000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __list_del_entry include/linux/list.h:131 [inline] list_del_init include/linux/list.h:190 [inline] trace_probe_unlink+0x1f/0x200 kernel/trace/trace_probe.c:959 trace_probe_cleanup+0xd3/0x110 kernel/trace/trace_probe.c:973 trace_probe_init+0x3f2/0x510 kernel/trace/trace_probe.c:1011 alloc_trace_uprobe+0x5e/0x250 kernel/trace/trace_uprobe.c:353 create_local_trace_uprobe+0x109/0x4a0 kernel/trace/trace_uprobe.c:1508 perf_uprobe_init+0x131/0x210 kernel/trace/trace_event_perf.c:314 perf_uprobe_event_init+0x106/0x1a0 kernel/events/core.c:8898 perf_try_init_event+0x135/0x590 kernel/events/core.c:10184 perf_init_event kernel/events/core.c:10228 [inline] perf_event_alloc.part.0+0x1b89/0x33d0 kernel/events/core.c:10505 perf_event_alloc kernel/events/core.c:10887 [inline] __do_sys_perf_event_open+0xa2d/0x2d00 kernel/events/core.c:10989 __se_sys_perf_event_open kernel/events/core.c:10871 [inline] __x64_sys_perf_event_open+0xbe/0x150 kernel/events/core.c:10871 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Link: http://lkml.kernel.org/r/156869709721.22406.5153754822203046939.stgit@devnote2 Reported-by: syzbot+2f807f4d3a2a4e87f18f@syzkaller.appspotmail.com Fixes: ca89bc071d5e ("tracing/kprobe: Add multi-probe per event support") Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

tracing/probe: Add immediate string parameter support

2019-08-31T16:19:39Z

Add immediate string parameter (\"string") support to probe events. This allows you to specify an immediate (or dummy) parameter instead of fetching a string from memory. This feature looks odd, but imagine that you put a probe on a code to trace some string data. If the code is compiled into 2 instructions and 1 instruction has a string on memory but other has no string since it is optimized out. In that case, you can not fold those into one event, even if ftrace supported multiple probes on one event. With this feature, you can set a dummy string like foo=\"(optimized)":string instead of something like foo=+0(+0(%bp)):string. Link: http://lkml.kernel.org/r/156095691687.28024.13372712423865047991.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

tracing/probe: Add immediate parameter support

2019-08-31T16:19:39Z

Add immediate value parameter (\1234) support to probe events. This allows you to specify an immediate (or dummy) parameter instead of fetching from memory or register. This feature looks odd, but imagine when you put a probe on a code to trace some data. If the code is compiled into 2 instructions and 1 instruction has a value but other has nothing since it is optimized out. In that case, you can not fold those into one event, even if ftrace supported multiple probes on one event. With this feature, you can set a dummy value like foo=\deadbeef instead of something like foo=%di. Link: http://lkml.kernel.org/r/156095690733.28024.13258186548822649469.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

tracing/kprobe: Add per-probe delete from event

2019-08-31T16:19:38Z

Allow user to delete a probe from event. This is done by head match. For example, if we have 2 probes on an event $ cat kprobe_events p:kprobes/testprobe _do_fork r1=%ax r2=%dx p:kprobes/testprobe idle_fork r1=%ax r2=%cx Then you can remove one of them by passing the head of definition which identify the probe. $ echo "-:kprobes/testprobe idle_fork" >> kprobe_events Link: http://lkml.kernel.org/r/156095688848.28024.15798690082378432435.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

tracing/kprobe: Add multi-probe per event support

2019-08-31T16:19:38Z

Add multi-probe per one event support to kprobe events. User can define several different probes on one trace event if those events have same "event signature", e.g. # echo p:testevent _do_fork > kprobe_events # echo p:testevent fork_idle >> kprobe_events # kprobe_events p:kprobes/testevent _do_fork p:kprobes/testevent fork_idle The event signature is defined by kprobe type (retprobe or not), the number of args, argument names, and argument types. Note that this only support appending method. Delete event operation will delete all probes on the event. Link: http://lkml.kernel.org/r/156095686913.28024.9357292202316540742.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

tracing/probe: Split trace_event related data from trace_probe

2019-08-31T16:19:38Z

Split the trace_event related data from trace_probe data structure and introduce trace_probe_event data structure for its folder. This trace_probe_event data structure can have multiple trace_probe. Link: http://lkml.kernel.org/r/156095683995.28024.7552150340561557873.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

tracing/probe: Fix null pointer dereference

2019-08-31T10:51:55Z

BUG: KASAN: null-ptr-deref in trace_probe_cleanup+0x8d/0xd0 Read of size 8 at addr 0000000000000000 by task syz-executor.0/9746 trace_probe_cleanup+0x8d/0xd0 free_trace_kprobe.part.14+0x15/0x50 alloc_trace_kprobe+0x23e/0x250 Link: http://lkml.kernel.org/r/1565220563-980-1-git-send-email-danielliu861@gmail.com Fixes: e3dc9f898ef9c ("tracing/probe: Add trace_event_call accesses APIs") Signed-off-by: Xinpeng Liu Signed-off-by: Steven Rostedt (VMware)

tracing/probe: Add trace_event_call accesses APIs

2019-07-16T19:14:47Z

Add trace_event_call access APIs for trace_probe. Instead of accessing trace_probe.call directly, use those accesses by trace_probe_event_call() method. This hides the relationship of trace_event_call and trace_probe from trace_kprobe and trace_uprobe. Link: http://lkml.kernel.org/r/155931587711.28323.8335129014686133120.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

tracing/probe: Add trace flag access APIs for trace_probe

2019-07-16T19:14:47Z

Add trace_probe_test/set/clear_flag() functions for accessing trace_probe.flag field. This flags field should not be accessed directly. Link: http://lkml.kernel.org/r/155931585683.28323.314290023236905988.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)