[ Upstream commit 6a5a148aaf ]
bpf_probe_read_kernel() has a __weak definition in core.c and another
definition with an incompatible prototype in kernel/trace/bpf_trace.c,
when CONFIG_BPF_EVENTS is enabled.
Since the two are incompatible, there cannot be a shared declaration in
a header file, but the lack of a prototype causes a W=1 warning:
kernel/bpf/core.c:1638:12: error: no previous prototype for 'bpf_probe_read_kernel' [-Werror=missing-prototypes]
On 32-bit architectures, the local prototype
u64 __weak bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr)
passes arguments in other registers as the one in bpf_trace.c
BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size,
const void *, unsafe_ptr)
which uses 64-bit arguments in pairs of registers.
As both versions of the function are fairly simple and only really
differ in one line, just move them into a header file as an inline
function that does not add any overhead for the bpf_trace.c callers
and actually avoids a function call for the other one.
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/ac25cb0f-b804-1649-3afb-1dc6138c2716@iogearbox.net/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230801111449.185301-1-arnd@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3163f635b2 ]
Warning happened in rb_end_commit() at code:
if (RB_WARN_ON(cpu_buffer, !local_read(&cpu_buffer->committing)))
WARNING: CPU: 0 PID: 139 at kernel/trace/ring_buffer.c:3142
rb_commit+0x402/0x4a0
Call Trace:
ring_buffer_unlock_commit+0x42/0x250
trace_buffer_unlock_commit_regs+0x3b/0x250
trace_event_buffer_commit+0xe5/0x440
trace_event_buffer_reserve+0x11c/0x150
trace_event_raw_event_sched_switch+0x23c/0x2c0
__traceiter_sched_switch+0x59/0x80
__schedule+0x72b/0x1580
schedule+0x92/0x120
worker_thread+0xa0/0x6f0
It is because the race between writing event into cpu buffer and swapping
cpu buffer through file per_cpu/cpu0/snapshot:
Write on CPU 0 Swap buffer by per_cpu/cpu0/snapshot on CPU 1
-------- --------
tracing_snapshot_write()
[...]
ring_buffer_lock_reserve()
cpu_buffer = buffer->buffers[cpu]; // 1. Suppose find 'cpu_buffer_a';
[...]
rb_reserve_next_event()
[...]
ring_buffer_swap_cpu()
if (local_read(&cpu_buffer_a->committing))
goto out_dec;
if (local_read(&cpu_buffer_b->committing))
goto out_dec;
buffer_a->buffers[cpu] = cpu_buffer_b;
buffer_b->buffers[cpu] = cpu_buffer_a;
// 2. cpu_buffer has swapped here.
rb_start_commit(cpu_buffer);
if (unlikely(READ_ONCE(cpu_buffer->buffer)
!= buffer)) { // 3. This check passed due to 'cpu_buffer->buffer'
[...] // has not changed here.
return NULL;
}
cpu_buffer_b->buffer = buffer_a;
cpu_buffer_a->buffer = buffer_b;
[...]
// 4. Reserve event from 'cpu_buffer_a'.
ring_buffer_unlock_commit()
[...]
cpu_buffer = buffer->buffers[cpu]; // 5. Now find 'cpu_buffer_b' !!!
rb_commit(cpu_buffer)
rb_end_commit() // 6. WARN for the wrong 'committing' state !!!
Based on above analysis, we can easily reproduce by following testcase:
``` bash
#!/bin/bash
dmesg -n 7
sysctl -w kernel.panic_on_warn=1
TR=/sys/kernel/tracing
echo 7 > ${TR}/buffer_size_kb
echo "sched:sched_switch" > ${TR}/set_event
while [ true ]; do
echo 1 > ${TR}/per_cpu/cpu0/snapshot
done &
while [ true ]; do
echo 1 > ${TR}/per_cpu/cpu0/snapshot
done &
while [ true ]; do
echo 1 > ${TR}/per_cpu/cpu0/snapshot
done &
```
To fix it, IIUC, we can use smp_call_function_single() to do the swap on
the target cpu where the buffer is located, so that above race would be
avoided.
Link: https://lore.kernel.org/linux-trace-kernel/20230831132739.4070878-1-zhengyejian1@huawei.com
Cc: <mhiramat@kernel.org>
Fixes: f1affcaaa8 ("tracing: Add snapshot in the per_cpu trace directories")
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2cf0dee989 ]
Space is printed after each mode value including the last one:
$ echo \"$(sudo cat /sys/kernel/tracing/hwlat_detector/mode)\"
"none [round-robin] per-cpu "
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Link: https://lore.kernel.org/linux-trace-kernel/20230825103432.7750-1-m.kobuk@ispras.ru
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 8fa826b734 ("trace/hwlat: Implement the mode config option")
Signed-off-by: Mikhail Kobuk <m.kobuk@ispras.ru>
Reviewed-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5125e757e6 ]
To avoid returning uninitialized or random values when querying the file
descriptor (fd) and accessing probe_addr, it is necessary to clear the
variable prior to its use.
Fixes: 41bdc4b40e ("bpf: introduce bpf subcommand BPF_TASK_FD_QUERY")
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230709025630.3735-6-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 3d07fa1dd1 upstream.
The pipe cpumask used to serialize opens between the main and percpu
trace pipes is not zeroed or initialized. This can result in
spurious -EBUSY returns if underlying memory is not fully zeroed.
This has been observed by immediate failure to read the main
trace_pipe file on an otherwise newly booted and idle system:
# cat /sys/kernel/debug/tracing/trace_pipe
cat: /sys/kernel/debug/tracing/trace_pipe: Device or resource busy
Zero the allocation of pipe_cpumask to avoid the problem.
Link: https://lore.kernel.org/linux-trace-kernel/20230831125500.986862-1-bfoster@redhat.com
Cc: stable@vger.kernel.org
Fixes: c2489bb7e6 ("tracing: Introduce pipe_cpumask to avoid race on trace_pipes")
Reviewed-by: Zheng Yejian <zhengyejian1@huawei.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is race issue when concurrently splice_read main trace_pipe and
per_cpu trace_pipes which will result in data read out being different
from what actually writen.
As suggested by Steven:
> I believe we should add a ref count to trace_pipe and the per_cpu
> trace_pipes, where if they are opened, nothing else can read it.
>
> Opening trace_pipe locks all per_cpu ref counts, if any of them are
> open, then the trace_pipe open will fail (and releases any ref counts
> it had taken).
>
> Opening a per_cpu trace_pipe will up the ref count for just that
> CPU buffer. This will allow multiple tasks to read different per_cpu
> trace_pipe files, but will prevent the main trace_pipe file from
> being opened.
But because we only need to know whether per_cpu trace_pipe is open or
not, using a cpumask instead of using ref count may be easier.
After this patch, users will find that:
- Main trace_pipe can be opened by only one user, and if it is
opened, all per_cpu trace_pipes cannot be opened;
- Per_cpu trace_pipes can be opened by multiple users, but each per_cpu
trace_pipe can only be opened by one user. And if one of them is
opened, main trace_pipe cannot be opened.
Link: https://lore.kernel.org/linux-trace-kernel/20230818022645.1948314-1-zhengyejian1@huawei.com
Suggested-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Kmemleak report a leak in graph_trace_open():
unreferenced object 0xffff0040b95f4a00 (size 128):
comm "cat", pid 204981, jiffies 4301155872 (age 99771.964s)
hex dump (first 32 bytes):
e0 05 e7 b4 ab 7d 00 00 0b 00 01 00 00 00 00 00 .....}..........
f4 00 01 10 00 a0 ff ff 00 00 00 00 65 00 10 00 ............e...
backtrace:
[<000000005db27c8b>] kmem_cache_alloc_trace+0x348/0x5f0
[<000000007df90faa>] graph_trace_open+0xb0/0x344
[<00000000737524cd>] __tracing_open+0x450/0xb10
[<0000000098043327>] tracing_open+0x1a0/0x2a0
[<00000000291c3876>] do_dentry_open+0x3c0/0xdc0
[<000000004015bcd6>] vfs_open+0x98/0xd0
[<000000002b5f60c9>] do_open+0x520/0x8d0
[<00000000376c7820>] path_openat+0x1c0/0x3e0
[<00000000336a54b5>] do_filp_open+0x14c/0x324
[<000000002802df13>] do_sys_openat2+0x2c4/0x530
[<0000000094eea458>] __arm64_sys_openat+0x130/0x1c4
[<00000000a71d7881>] el0_svc_common.constprop.0+0xfc/0x394
[<00000000313647bf>] do_el0_svc+0xac/0xec
[<000000002ef1c651>] el0_svc+0x20/0x30
[<000000002fd4692a>] el0_sync_handler+0xb0/0xb4
[<000000000c309c35>] el0_sync+0x160/0x180
The root cause is descripted as follows:
__tracing_open() { // 1. File 'trace' is being opened;
...
*iter->trace = *tr->current_trace; // 2. Tracer 'function_graph' is
// currently set;
...
iter->trace->open(iter); // 3. Call graph_trace_open() here,
// and memory are allocated in it;
...
}
s_start() { // 4. The opened file is being read;
...
*iter->trace = *tr->current_trace; // 5. If tracer is switched to
// 'nop' or others, then memory
// in step 3 are leaked!!!
...
}
To fix it, in s_start(), close tracer before switching then reopen the
new tracer after switching. And some tracers like 'wakeup' may not update
'iter->private' in some cases when reopen, then it should be cleared
to avoid being mistakenly closed again.
Link: https://lore.kernel.org/linux-trace-kernel/20230817125539.1646321-1-zhengyejian1@huawei.com
Fixes: d7350c3f45 ("tracing/core: make the read callbacks reentrants")
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
While debugging another issue I noticed that the stack trace contains one
invalid entry at the end:
<idle>-0 [008] d..4. 26.484201: wake_lat: pid=0 delta=2629976084 000000009cc24024 stack=STACK:
=> __schedule+0xac6/0x1a98
=> schedule+0x126/0x2c0
=> schedule_timeout+0x150/0x2c0
=> kcompactd+0x9ca/0xc20
=> kthread+0x2f6/0x3d8
=> __ret_from_fork+0x8a/0xe8
=> 0x6b6b6b6b6b6b6b6b
This is because the code failed to add the one element containing the
number of entries to field_size.
Link: https://lkml.kernel.org/r/20230816154928.4171614-4-svens@linux.ibm.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 00cf3d672a ("tracing: Allow synthetic events to pass around stacktraces")
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
While debugging another issue I noticed that the stack trace output
contains the number of entries on top:
<idle>-0 [000] d..4. 203.322502: wake_lat: pid=0 delta=2268270616 stack=STACK:
=> 0x10
=> __schedule+0xac6/0x1a98
=> schedule+0x126/0x2c0
=> schedule_timeout+0x242/0x2c0
=> __wait_for_common+0x434/0x680
=> __wait_rcu_gp+0x198/0x3e0
=> synchronize_rcu+0x112/0x138
=> ring_buffer_reset_online_cpus+0x140/0x2e0
=> tracing_reset_online_cpus+0x15c/0x1d0
=> tracing_set_clock+0x180/0x1d8
=> hist_register_trigger+0x486/0x670
=> event_hist_trigger_parse+0x494/0x1318
=> trigger_process_regex+0x1d4/0x258
=> event_trigger_write+0xb4/0x170
=> vfs_write+0x210/0xad0
=> ksys_write+0x122/0x208
Fix this by skipping the first element. Also replace the pointer
logic with an index variable which is easier to read.
Link: https://lkml.kernel.org/r/20230816154928.4171614-3-svens@linux.ibm.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 00cf3d672a ("tracing: Allow synthetic events to pass around stacktraces")
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The current code uses a lot of casts to access the fields member in struct
synth_trace_events with different sizes. This makes the code hard to
read, and had already introduced an endianness bug. Use a union and struct
instead.
Link: https://lkml.kernel.org/r/20230816154928.4171614-2-svens@linux.ibm.com
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 00cf3d672a ("tracing: Allow synthetic events to pass around stacktraces")
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Trace ring buffer can no longer record anything after executing
following commands at the shell prompt:
# cd /sys/kernel/tracing
# cat tracing_cpumask
fff
# echo 0 > tracing_cpumask
# echo 1 > snapshot
# echo fff > tracing_cpumask
# echo 1 > tracing_on
# echo "hello world" > trace_marker
-bash: echo: write error: Bad file descriptor
The root cause is that:
1. After `echo 0 > tracing_cpumask`, 'record_disabled' of cpu buffers
in 'tr->array_buffer.buffer' became 1 (see tracing_set_cpumask());
2. After `echo 1 > snapshot`, 'tr->array_buffer.buffer' is swapped
with 'tr->max_buffer.buffer', then the 'record_disabled' became 0
(see update_max_tr());
3. After `echo fff > tracing_cpumask`, the 'record_disabled' become -1;
Then array_buffer and max_buffer are both unavailable due to value of
'record_disabled' is not 0.
To fix it, enable or disable both array_buffer and max_buffer at the same
time in tracing_set_cpumask().
Link: https://lkml.kernel.org/r/20230805033816.3284594-2-zhengyejian1@huawei.com
Cc: <mhiramat@kernel.org>
Cc: <vnagarnaik@google.com>
Cc: <shuah@kernel.org>
Fixes: 71babb2705 ("tracing: change CPU ring buffer state from tracing_cpumask")
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Nothing scary here. Feels like the first wave of regressions
from v6.5 is addressed - one outstanding fix still to come
in TLS for the sendpage rework.
Current release - regressions:
- udp: fix __ip_append_data()'s handling of MSG_SPLICE_PAGES
- dsa: fix older DSA drivers using phylink
Previous releases - regressions:
- gro: fix misuse of CB in udp socket lookup
- mlx5: unregister devlink params in case interface is down
- Revert "wifi: ath11k: Enable threaded NAPI"
Previous releases - always broken:
- sched: cls_u32: fix match key mis-addressing
- sched: bind logic fixes for cls_fw, cls_u32 and cls_route
- add bound checks to a number of places which hand-parse netlink
- bpf: disable preemption in perf_event_output helpers code
- qed: fix scheduling in a tasklet while getting stats
- avoid using APIs which are not hardirq-safe in couple of drivers,
when we may be in a hard IRQ (netconsole)
- wifi: cfg80211: fix return value in scan logic, avoid page
allocator warning
- wifi: mt76: mt7615: do not advertise 5 GHz on first PHY
of MT7615D (DBDC)
Misc:
- drop handful of inactive maintainers, put some new in place
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
-----BEGIN PGP SIGNATURE-----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=HYkl
-----END PGP SIGNATURE-----
Merge tag 'net-6.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Jakub Kicinski:
"Including fixes from bpf and wireless.
Nothing scary here. Feels like the first wave of regressions from v6.5
is addressed - one outstanding fix still to come in TLS for the
sendpage rework.
Current release - regressions:
- udp: fix __ip_append_data()'s handling of MSG_SPLICE_PAGES
- dsa: fix older DSA drivers using phylink
Previous releases - regressions:
- gro: fix misuse of CB in udp socket lookup
- mlx5: unregister devlink params in case interface is down
- Revert "wifi: ath11k: Enable threaded NAPI"
Previous releases - always broken:
- sched: cls_u32: fix match key mis-addressing
- sched: bind logic fixes for cls_fw, cls_u32 and cls_route
- add bound checks to a number of places which hand-parse netlink
- bpf: disable preemption in perf_event_output helpers code
- qed: fix scheduling in a tasklet while getting stats
- avoid using APIs which are not hardirq-safe in couple of drivers,
when we may be in a hard IRQ (netconsole)
- wifi: cfg80211: fix return value in scan logic, avoid page
allocator warning
- wifi: mt76: mt7615: do not advertise 5 GHz on first PHY of MT7615D
(DBDC)
Misc:
- drop handful of inactive maintainers, put some new in place"
* tag 'net-6.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (98 commits)
MAINTAINERS: update TUN/TAP maintainers
test/vsock: remove vsock_perf executable on `make clean`
tcp_metrics: fix data-race in tcpm_suck_dst() vs fastopen
tcp_metrics: annotate data-races around tm->tcpm_net
tcp_metrics: annotate data-races around tm->tcpm_vals[]
tcp_metrics: annotate data-races around tm->tcpm_lock
tcp_metrics: annotate data-races around tm->tcpm_stamp
tcp_metrics: fix addr_same() helper
prestera: fix fallback to previous version on same major version
udp: Fix __ip_append_data()'s handling of MSG_SPLICE_PAGES
net/mlx5e: Set proper IPsec source port in L4 selector
net/mlx5: fs_core: Skip the FTs in the same FS_TYPE_PRIO_CHAINS fs_prio
net/mlx5: fs_core: Make find_closest_ft more generic
wifi: brcmfmac: Fix field-spanning write in brcmf_scan_params_v2_to_v1()
vxlan: Fix nexthop hash size
ip6mr: Fix skb_under_panic in ip6mr_cache_report()
s390/qeth: Don't call dev_close/dev_open (DOWN/UP)
net: tap_open(): set sk_uid from current_fsuid()
net: tun_chr_open(): set sk_uid from current_fsuid()
net: dcb: choose correct policy to parse DCB_ATTR_BCN
...
-----BEGIN PGP SIGNATURE-----
iHUEABYIAB0WIQRdM/uy1Ege0+EN1fNar9k/UBDW4wUCZMvqewAKCRBar9k/UBDW
48yeAQCnPnwzcvy+JDrdosuJEErhMv0pH3ECixNpPBpns95kzAEA9QhSYwjAhlFf
61d6hoiXj/sIibgMQT/ihODgeJ4wfQE=
=u7qn
-----END PGP SIGNATURE-----
Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Martin KaFai Lau says:
====================
pull-request: bpf 2023-08-03
We've added 5 non-merge commits during the last 7 day(s) which contain
a total of 3 files changed, 37 insertions(+), 20 deletions(-).
The main changes are:
1) Disable preemption in perf_event_output helpers code,
from Jiri Olsa
2) Add length check for SK_DIAG_BPF_STORAGE_REQ_MAP_FD parsing,
from Lin Ma
3) Multiple warning splat fixes in cpumap from Hou Tao
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
bpf, cpumap: Handle skb as well when clean up ptr_ring
bpf, cpumap: Make sure kthread is running before map update returns
bpf: Add length check for SK_DIAG_BPF_STORAGE_REQ_MAP_FD parsing
bpf: Disable preemption in bpf_event_output
bpf: Disable preemption in bpf_perf_event_output
====================
Link: https://lore.kernel.org/r/20230803181429.994607-1-martin.lau@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
- probe-events: Fix to add NULL check for some BTF API calls which can
return error code and NULL.
- ftrace selftests: Fix to check fprobe and kprobe event correctly. This
fixes a miss condition of the test command.
- kprobes: Prohibit probing on the function which starts from "__cfi_"
and "__pfx_" since those are auto generated for kernel CFI and not
executed.
-----BEGIN PGP SIGNATURE-----
iQFPBAABCgA5FiEEh7BulGwFlgAOi5DV2/sHvwUrPxsFAmTGdH4bHG1hc2FtaS5o
aXJhbWF0c3VAZ21haWwuY29tAAoJENv7B78FKz8bmMAH/0qTHII0KYQDvrNJ40tT
SDM8+4zOJEtnjVYq87+4EWBhpVEL3VbLRJaprjXh40lZJrCP3MglCF152p4bOhgb
ZrjWuTAgE0N+rBhdeUJlzy3iLzl0G9dzfA+sn1XMcW+/HSPstJcjAG6wD7ROeZzL
XCxzE+NY6Y6mYbB52DaS8Hv7g7WccaTV+KeRjokhMPt+u7/KItJ4hQb/RXtAL31S
n4thCeVllaPBuc7m2CmKwJ9jzOg7/0qpAIUGx1Z+Khy/3YfRhG1nT93GxP8hLmad
SH9kGps09WXF5f8FbjYglOmq7ioDbIUz3oXPQRZYPymV8A0EU+b+/8IsRog1ySd1
BVk=
=qKWS
-----END PGP SIGNATURE-----
Merge tag 'probes-fixes-v6.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull probe fixes from Masami Hiramatsu:
- probe-events: add NULL check for some BTF API calls which can return
error code and NULL.
- ftrace selftests: check fprobe and kprobe event correctly. This fixes
a miss condition of the test command.
- kprobes: do not allow probing functions that start with "__cfi_" or
"__pfx_" since those are auto generated for kernel CFI and not
executed.
* tag 'probes-fixes-v6.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
kprobes: Prohibit probing on CFI preamble symbol
selftests/ftrace: Fix to check fprobe event eneblement
tracing/probes: Fix to add NULL check for BTF APIs
Warning happened in trace_buffered_event_disable() at
WARN_ON_ONCE(!trace_buffered_event_ref)
Call Trace:
? __warn+0xa5/0x1b0
? trace_buffered_event_disable+0x189/0x1b0
__ftrace_event_enable_disable+0x19e/0x3e0
free_probe_data+0x3b/0xa0
unregister_ftrace_function_probe_func+0x6b8/0x800
event_enable_func+0x2f0/0x3d0
ftrace_process_regex.isra.0+0x12d/0x1b0
ftrace_filter_write+0xe6/0x140
vfs_write+0x1c9/0x6f0
[...]
The cause of the warning is in __ftrace_event_enable_disable(),
trace_buffered_event_enable() was called once while
trace_buffered_event_disable() was called twice.
Reproduction script show as below, for analysis, see the comments:
```
#!/bin/bash
cd /sys/kernel/tracing/
# 1. Register a 'disable_event' command, then:
# 1) SOFT_DISABLED_BIT was set;
# 2) trace_buffered_event_enable() was called first time;
echo 'cmdline_proc_show:disable_event:initcall:initcall_finish' > \
set_ftrace_filter
# 2. Enable the event registered, then:
# 1) SOFT_DISABLED_BIT was cleared;
# 2) trace_buffered_event_disable() was called first time;
echo 1 > events/initcall/initcall_finish/enable
# 3. Try to call into cmdline_proc_show(), then SOFT_DISABLED_BIT was
# set again!!!
cat /proc/cmdline
# 4. Unregister the 'disable_event' command, then:
# 1) SOFT_DISABLED_BIT was cleared again;
# 2) trace_buffered_event_disable() was called second time!!!
echo '!cmdline_proc_show:disable_event:initcall:initcall_finish' > \
set_ftrace_filter
```
To fix it, IIUC, we can change to call trace_buffered_event_enable() at
fist time soft-mode enabled, and call trace_buffered_event_disable() at
last time soft-mode disabled.
Link: https://lore.kernel.org/linux-trace-kernel/20230726095804.920457-1-zhengyejian1@huawei.com
Cc: <mhiramat@kernel.org>
Fixes: 0fc1b09ff1 ("tracing: Use temp buffer when filtering events")
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Fix kernel-doc warning:
kernel/trace/trace_seq.c:142: warning: Function parameter or member
'args' not described in 'trace_seq_vprintf'
Link: https://lkml.kernel.org/r/20230724140827.1023266-5-cuigaosheng1@huawei.com
Cc: <mhiramat@kernel.org>
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Fix kernel-doc warnings:
kernel/trace/trace_events_trigger.c:59: warning: Function parameter
or member 'buffer' not described in 'event_triggers_call'
kernel/trace/trace_events_trigger.c:59: warning: Function parameter
or member 'event' not described in 'event_triggers_call'
Link: https://lkml.kernel.org/r/20230724140827.1023266-4-cuigaosheng1@huawei.com
Cc: <mhiramat@kernel.org>
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Fix kernel-doc warning:
kernel/trace/trace_events_synth.c:1257: warning: Function parameter
or member 'mod' not described in 'synth_event_gen_cmd_array_start'
Link: https://lkml.kernel.org/r/20230724140827.1023266-3-cuigaosheng1@huawei.com
Cc: <mhiramat@kernel.org>
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Fix kernel-doc warnings:
kernel/trace/ring_buffer.c:954: warning: Function parameter or
member 'cpu' not described in 'ring_buffer_wake_waiters'
kernel/trace/ring_buffer.c:3383: warning: Excess function parameter
'event' description in 'ring_buffer_unlock_commit'
kernel/trace/ring_buffer.c:5359: warning: Excess function parameter
'cpu' description in 'ring_buffer_reset_online_cpus'
Link: https://lkml.kernel.org/r/20230724140827.1023266-2-cuigaosheng1@huawei.com
Cc: <mhiramat@kernel.org>
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When pages are removed in rb_remove_pages(), 'cpu_buffer->read' is set
to 0 in order to make sure any read iterators reset themselves. However,
this will mess 'entries' stating, see following steps:
# cd /sys/kernel/tracing/
# 1. Enlarge ring buffer prepare for later reducing:
# echo 20 > per_cpu/cpu0/buffer_size_kb
# 2. Write a log into ring buffer of cpu0:
# taskset -c 0 echo "hello1" > trace_marker
# 3. Read the log:
# cat per_cpu/cpu0/trace_pipe
<...>-332 [000] ..... 62.406844: tracing_mark_write: hello1
# 4. Stop reading and see the stats, now 0 entries, and 1 event readed:
# cat per_cpu/cpu0/stats
entries: 0
[...]
read events: 1
# 5. Reduce the ring buffer
# echo 7 > per_cpu/cpu0/buffer_size_kb
# 6. Now entries became unexpected 1 because actually no entries!!!
# cat per_cpu/cpu0/stats
entries: 1
[...]
read events: 0
To fix it, introduce 'page_removed' field to count total removed pages
since last reset, then use it to let read iterators reset themselves
instead of changing the 'read' pointer.
Link: https://lore.kernel.org/linux-trace-kernel/20230724054040.3489499-1-zhengyejian1@huawei.com
Cc: <mhiramat@kernel.org>
Cc: <vnagarnaik@google.com>
Fixes: 83f40318da ("ring-buffer: Make removal of ring buffer pages atomic")
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Since find_btf_func_param() abd btf_type_by_id() can return NULL,
the caller must check the return value correctly.
Link: https://lore.kernel.org/all/169024903951.395371.11361556840733470934.stgit@devnote2/
Fixes: b576e09701 ("tracing/probes: Support function parameters if BTF is available")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
We received report [1] of kernel crash, which is caused by
using nesting protection without disabled preemption.
The bpf_event_output can be called by programs executed by
bpf_prog_run_array_cg function that disabled migration but
keeps preemption enabled.
This can cause task to be preempted by another one inside the
nesting protection and lead eventually to two tasks using same
perf_sample_data buffer and cause crashes like:
BUG: kernel NULL pointer dereference, address: 0000000000000001
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
...
? perf_output_sample+0x12a/0x9a0
? finish_task_switch.isra.0+0x81/0x280
? perf_event_output+0x66/0xa0
? bpf_event_output+0x13a/0x190
? bpf_event_output_data+0x22/0x40
? bpf_prog_dfc84bbde731b257_cil_sock4_connect+0x40a/0xacb
? xa_load+0x87/0xe0
? __cgroup_bpf_run_filter_sock_addr+0xc1/0x1a0
? release_sock+0x3e/0x90
? sk_setsockopt+0x1a1/0x12f0
? udp_pre_connect+0x36/0x50
? inet_dgram_connect+0x93/0xa0
? __sys_connect+0xb4/0xe0
? udp_setsockopt+0x27/0x40
? __pfx_udp_push_pending_frames+0x10/0x10
? __sys_setsockopt+0xdf/0x1a0
? __x64_sys_connect+0xf/0x20
? do_syscall_64+0x3a/0x90
? entry_SYSCALL_64_after_hwframe+0x72/0xdc
Fixing this by disabling preemption in bpf_event_output.
[1] https://github.com/cilium/cilium/issues/26756
Cc: stable@vger.kernel.org
Reported-by: Oleg "livelace" Popov <o.popov@livelace.ru>
Closes: https://github.com/cilium/cilium/issues/26756
Fixes: 2a916f2f54 ("bpf: Use migrate_disable/enable in array macros and cgroup/lirc code.")
Acked-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230725084206.580930-3-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The nesting protection in bpf_perf_event_output relies on disabled
preemption, which is guaranteed for kprobes and tracepoints.
However bpf_perf_event_output can be also called from uprobes context
through bpf_prog_run_array_sleepable function which disables migration,
but keeps preemption enabled.
This can cause task to be preempted by another one inside the nesting
protection and lead eventually to two tasks using same perf_sample_data
buffer and cause crashes like:
kernel tried to execute NX-protected page - exploit attempt? (uid: 0)
BUG: unable to handle page fault for address: ffffffff82be3eea
...
Call Trace:
? __die+0x1f/0x70
? page_fault_oops+0x176/0x4d0
? exc_page_fault+0x132/0x230
? asm_exc_page_fault+0x22/0x30
? perf_output_sample+0x12b/0x910
? perf_event_output+0xd0/0x1d0
? bpf_perf_event_output+0x162/0x1d0
? bpf_prog_c6271286d9a4c938_krava1+0x76/0x87
? __uprobe_perf_func+0x12b/0x540
? uprobe_dispatcher+0x2c4/0x430
? uprobe_notify_resume+0x2da/0xce0
? atomic_notifier_call_chain+0x7b/0x110
? exit_to_user_mode_prepare+0x13e/0x290
? irqentry_exit_to_user_mode+0x5/0x30
? asm_exc_int3+0x35/0x40
Fixing this by disabling preemption in bpf_perf_event_output.
Cc: stable@vger.kernel.org
Fixes: 8c7dcb84e3 ("bpf: implement sleepable uprobes by chaining gps")
Acked-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230725084206.580930-2-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Commit 6018b585e8 ("tracing/histograms: Add histograms to hist_vars if
they have referenced variables") added a check to fail histogram creation
if save_hist_vars() failed to add histogram to hist_vars list. But the
commit failed to set ret to failed return code before jumping to
unregister histogram, fix it.
Link: https://lore.kernel.org/linux-trace-kernel/20230714203341.51396-1-mkhalfella@purestorage.com
Cc: stable@vger.kernel.org
Fixes: 6018b585e8 ("tracing/histograms: Add histograms to hist_vars if they have referenced variables")
Signed-off-by: Mohamed Khalfella <mkhalfella@purestorage.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
- fprobe: Add a comment why fprobe will be skipped if another kprobe is
running in fprobe_kprobe_handler().
- probe-events: Fix some issues related to fetch-argument
. Fix double counting of the string length for user-string and symstr.
This will require longer buffer in the array case.
. Fix not to count error code (minus value) for the total used length
in array argument. This makes the total used length shorter.
. Fix to update dynamic used data size counter only if fetcharg uses
the dynamic size data. This may mis-count the used dynamic data
size and corrupt data.
. Revert "tracing: Add "(fault)" name injection to kernel probes"
because that did not work correctly with a bug, and we agreed the
current '(fault)' output (instead of '"(fault)"' like a string)
explains what happened more clearly.
. Fix to record 0-length (means fault access) data_loc data in fetch
function itself, instead of store_trace_args(). If we record an
array of string, this will fix to save fault access data on each
entry of the array correctly.
-----BEGIN PGP SIGNATURE-----
iQEzBAABCgAdFiEEh7BulGwFlgAOi5DV2/sHvwUrPxsFAmSxSlYACgkQ2/sHvwUr
PxupyAgApFDi9YGsmrVbXmIN5y+yGMyio2H6xR7XkX+L02nvDY6uVqL/jgT8pHfI
AeGZEA+EqwxIfWpYBfztsFej+Gl3Elfvu14OSxwaafUlW3mgZFQqw1ZR0HvzXoKJ
8Iw6WOXjhLe3/QLy43UY8JQGOKI07i3gh71wa0W0huOyiwwHuuVwPSY9QJJ2ulSg
OWFSuMFO8IxYimp0BpFu/vrfa8CdgWLc24tgJ5EpZtzu6L0A2I/FMZjnBukxnP9s
rjAXv0uRuSFvvF7/RGCqrLza12525qyHx7d5IWUq5shd3bCnaUOnAieF//MoJaR3
q8McDJK//EPbUvCWgESuuyPS05smyQ==
=iumA
-----END PGP SIGNATURE-----
Merge tag 'probes-fixes-v6.5-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull probe fixes from Masami Hiramatsu:
- fprobe: Add a comment why fprobe will be skipped if another kprobe is
running in fprobe_kprobe_handler().
- probe-events: Fix some issues related to fetch-arguments:
- Fix double counting of the string length for user-string and
symstr. This will require longer buffer in the array case.
- Fix not to count error code (minus value) for the total used
length in array argument. This makes the total used length
shorter.
- Fix to update dynamic used data size counter only if fetcharg uses
the dynamic size data. This may mis-count the used dynamic data
size and corrupt data.
- Revert "tracing: Add "(fault)" name injection to kernel probes"
because that did not work correctly with a bug, and we agreed the
current '(fault)' output (instead of '"(fault)"' like a string)
explains what happened more clearly.
- Fix to record 0-length (means fault access) data_loc data in fetch
function itself, instead of store_trace_args(). If we record an
array of string, this will fix to save fault access data on each
entry of the array correctly.
* tag 'probes-fixes-v6.5-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing/probes: Fix to record 0-length data_loc in fetch_store_string*() if fails
Revert "tracing: Add "(fault)" name injection to kernel probes"
tracing/probes: Fix to update dynamic data counter if fetcharg uses it
tracing/probes: Fix not to count error code to total length
tracing/probes: Fix to avoid double count of the string length on the array
fprobes: Add a comment why fprobe_kprobe_handler exits if kprobe is running
Fix to record 0-length data to data_loc in fetch_store_string*() if it fails
to get the string data.
Currently those expect that the data_loc is updated by store_trace_args() if
it returns the error code. However, that does not work correctly if the
argument is an array of strings. In that case, store_trace_args() only clears
the first entry of the array (which may have no error) and leaves other
entries. So it should be cleared by fetch_store_string*() itself.
Also, 'dyndata' and 'maxlen' in store_trace_args() should be updated
only if it is used (ret > 0 and argument is a dynamic data.)
Link: https://lore.kernel.org/all/168908496683.123124.4761206188794205601.stgit@devnote2/
Fixes: 40b53b7718 ("tracing: probeevent: Add array type support")
Cc: stable@vger.kernel.org
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
- Fix some missing-prototype warnings
- Fix user events struct args (did not include size of struct)
When creating a user event, the "struct" keyword is to denote
that the size of the field will be passed in. But the parsing
failed to handle this case.
- Add selftest to struct sizes for user events
- Fix sample code for direct trampolines.
The sample code for direct trampolines attached to handle_mm_fault().
But the prototype changed and the direct trampoline sample code
was not updated. Direct trampolines needs to have the arguments correct
otherwise it can fail or crash the system.
- Remove unused ftrace_regs_caller_ret() prototype.
- Quiet false positive of FORTIFY_SOURCE
Due to backward compatibility, the structure used to save stack traces
in the kernel had a fixed size of 8. This structure is exported to
user space via the tracing format file. A change was made to allow
more than 8 functions to be recorded, and user space now uses the
size field to know how many functions are actually in the stack.
But the structure still has size of 8 (even though it points into
the ring buffer that has the required amount allocated to hold a
full stack. This was fine until the fortifier noticed that the
memcpy(&entry->caller, stack, size) was greater than the 8 functions
and would complain at runtime about it. Hide this by using a pointer
to the stack location on the ring buffer instead of using the address
of the entry structure caller field.
- Fix a deadloop in reading trace_pipe that was caused by a mismatch
between ring_buffer_empty() returning false which then asked to
read the data, but the read code uses rb_num_of_entries() that
returned zero, and causing a infinite "retry".
- Fix a warning caused by not using all pages allocated to store
ftrace functions, where this can happen if the linker inserts a bunch of
"NULL" entries, causing the accounting of how many pages needed
to be off.
- Fix histogram synthetic event crashing when the start event is
removed and the end event is still using a variable from it.
- Fix memory leak in freeing iter->temp in tracing_release_pipe()
-----BEGIN PGP SIGNATURE-----
iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCZLBF6hQccm9zdGVkdEBn
b29kbWlzLm9yZwAKCRAp5XQQmuv6qkswAP4mhdoFFfNosM7+Sh/R4t31IxKZApm9
M2Hf9jgvJ7b65AD/VV1XfO6skw2+5Yn9S4UyNE2MQaYxPwWpONcNFUzZ3Q8=
=Nb+7
-----END PGP SIGNATURE-----
Merge tag 'trace-v6.5-rc1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:
- Fix some missing-prototype warnings
- Fix user events struct args (did not include size of struct)
When creating a user event, the "struct" keyword is to denote that
the size of the field will be passed in. But the parsing failed to
handle this case.
- Add selftest to struct sizes for user events
- Fix sample code for direct trampolines.
The sample code for direct trampolines attached to handle_mm_fault().
But the prototype changed and the direct trampoline sample code was
not updated. Direct trampolines needs to have the arguments correct
otherwise it can fail or crash the system.
- Remove unused ftrace_regs_caller_ret() prototype.
- Quiet false positive of FORTIFY_SOURCE
Due to backward compatibility, the structure used to save stack
traces in the kernel had a fixed size of 8. This structure is
exported to user space via the tracing format file. A change was made
to allow more than 8 functions to be recorded, and user space now
uses the size field to know how many functions are actually in the
stack.
But the structure still has size of 8 (even though it points into the
ring buffer that has the required amount allocated to hold a full
stack.
This was fine until the fortifier noticed that the
memcpy(&entry->caller, stack, size) was greater than the 8 functions
and would complain at runtime about it.
Hide this by using a pointer to the stack location on the ring buffer
instead of using the address of the entry structure caller field.
- Fix a deadloop in reading trace_pipe that was caused by a mismatch
between ring_buffer_empty() returning false which then asked to read
the data, but the read code uses rb_num_of_entries() that returned
zero, and causing a infinite "retry".
- Fix a warning caused by not using all pages allocated to store ftrace
functions, where this can happen if the linker inserts a bunch of
"NULL" entries, causing the accounting of how many pages needed to be
off.
- Fix histogram synthetic event crashing when the start event is
removed and the end event is still using a variable from it
- Fix memory leak in freeing iter->temp in tracing_release_pipe()
* tag 'trace-v6.5-rc1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: Fix memory leak of iter->temp when reading trace_pipe
tracing/histograms: Add histograms to hist_vars if they have referenced variables
tracing: Stop FORTIFY_SOURCE complaining about stack trace caller
ftrace: Fix possible warning on checking all pages used in ftrace_process_locs()
ring-buffer: Fix deadloop issue on reading trace_pipe
tracing: arm64: Avoid missing-prototype warnings
selftests/user_events: Test struct size match cases
tracing/user_events: Fix struct arg size match check
x86/ftrace: Remove unsued extern declaration ftrace_regs_caller_ret()
arm64: ftrace: Add direct call trampoline samples support
samples: ftrace: Save required argument registers in sample trampolines
This reverts commit 2e9906f84f.
It was turned out that commit 2e9906f84f ("tracing: Add "(fault)"
name injection to kernel probes") did not work correctly and probe
events still show just '(fault)' (instead of '"(fault)"'). Also,
current '(fault)' is more explicit that it faulted.
This also moves FAULT_STRING macro to trace.h so that synthetic
event can keep using it, and uses it in trace_probe.c too.
Link: https://lore.kernel.org/all/168908495772.123124.1250788051922100079.stgit@devnote2/
Link: https://lore.kernel.org/all/20230706230642.3793a593@rorschach.local.home/
Cc: stable@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Hist triggers can have referenced variables without having direct
variables fields. This can be the case if referenced variables are added
for trigger actions. In this case the newly added references will not
have field variables. Not taking such referenced variables into
consideration can result in a bug where it would be possible to remove
hist trigger with variables being refenced. This will result in a bug
that is easily reproducable like so
$ cd /sys/kernel/tracing
$ echo 'synthetic_sys_enter char[] comm; long id' >> synthetic_events
$ echo 'hist:keys=common_pid.execname,id.syscall:vals=hitcount:comm=common_pid.execname' >> events/raw_syscalls/sys_enter/trigger
$ echo 'hist:keys=common_pid.execname,id.syscall:onmatch(raw_syscalls.sys_enter).synthetic_sys_enter($comm, id)' >> events/raw_syscalls/sys_enter/trigger
$ echo '!hist:keys=common_pid.execname,id.syscall:vals=hitcount:comm=common_pid.execname' >> events/raw_syscalls/sys_enter/trigger
[ 100.263533] ==================================================================
[ 100.264634] BUG: KASAN: slab-use-after-free in resolve_var_refs+0xc7/0x180
[ 100.265520] Read of size 8 at addr ffff88810375d0f0 by task bash/439
[ 100.266320]
[ 100.266533] CPU: 2 PID: 439 Comm: bash Not tainted 6.5.0-rc1 #4
[ 100.267277] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-20220807_005459-localhost 04/01/2014
[ 100.268561] Call Trace:
[ 100.268902] <TASK>
[ 100.269189] dump_stack_lvl+0x4c/0x70
[ 100.269680] print_report+0xc5/0x600
[ 100.270165] ? resolve_var_refs+0xc7/0x180
[ 100.270697] ? kasan_complete_mode_report_info+0x80/0x1f0
[ 100.271389] ? resolve_var_refs+0xc7/0x180
[ 100.271913] kasan_report+0xbd/0x100
[ 100.272380] ? resolve_var_refs+0xc7/0x180
[ 100.272920] __asan_load8+0x71/0xa0
[ 100.273377] resolve_var_refs+0xc7/0x180
[ 100.273888] event_hist_trigger+0x749/0x860
[ 100.274505] ? kasan_save_stack+0x2a/0x50
[ 100.275024] ? kasan_set_track+0x29/0x40
[ 100.275536] ? __pfx_event_hist_trigger+0x10/0x10
[ 100.276138] ? ksys_write+0xd1/0x170
[ 100.276607] ? do_syscall_64+0x3c/0x90
[ 100.277099] ? entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[ 100.277771] ? destroy_hist_data+0x446/0x470
[ 100.278324] ? event_hist_trigger_parse+0xa6c/0x3860
[ 100.278962] ? __pfx_event_hist_trigger_parse+0x10/0x10
[ 100.279627] ? __kasan_check_write+0x18/0x20
[ 100.280177] ? mutex_unlock+0x85/0xd0
[ 100.280660] ? __pfx_mutex_unlock+0x10/0x10
[ 100.281200] ? kfree+0x7b/0x120
[ 100.281619] ? ____kasan_slab_free+0x15d/0x1d0
[ 100.282197] ? event_trigger_write+0xac/0x100
[ 100.282764] ? __kasan_slab_free+0x16/0x20
[ 100.283293] ? __kmem_cache_free+0x153/0x2f0
[ 100.283844] ? sched_mm_cid_remote_clear+0xb1/0x250
[ 100.284550] ? __pfx_sched_mm_cid_remote_clear+0x10/0x10
[ 100.285221] ? event_trigger_write+0xbc/0x100
[ 100.285781] ? __kasan_check_read+0x15/0x20
[ 100.286321] ? __bitmap_weight+0x66/0xa0
[ 100.286833] ? _find_next_bit+0x46/0xe0
[ 100.287334] ? task_mm_cid_work+0x37f/0x450
[ 100.287872] event_triggers_call+0x84/0x150
[ 100.288408] trace_event_buffer_commit+0x339/0x430
[ 100.289073] ? ring_buffer_event_data+0x3f/0x60
[ 100.292189] trace_event_raw_event_sys_enter+0x8b/0xe0
[ 100.295434] syscall_trace_enter.constprop.0+0x18f/0x1b0
[ 100.298653] syscall_enter_from_user_mode+0x32/0x40
[ 100.301808] do_syscall_64+0x1a/0x90
[ 100.304748] entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[ 100.307775] RIP: 0033:0x7f686c75c1cb
[ 100.310617] Code: 73 01 c3 48 8b 0d 65 3c 10 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 21 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 35 3c 10 00 f7 d8 64 89 01 48
[ 100.317847] RSP: 002b:00007ffc60137a38 EFLAGS: 00000246 ORIG_RAX: 0000000000000021
[ 100.321200] RAX: ffffffffffffffda RBX: 000055f566469ea0 RCX: 00007f686c75c1cb
[ 100.324631] RDX: 0000000000000001 RSI: 0000000000000001 RDI: 000000000000000a
[ 100.328104] RBP: 00007ffc60137ac0 R08: 00007f686c818460 R09: 000000000000000a
[ 100.331509] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000009
[ 100.334992] R13: 0000000000000007 R14: 000000000000000a R15: 0000000000000007
[ 100.338381] </TASK>
We hit the bug because when second hist trigger has was created
has_hist_vars() returned false because hist trigger did not have
variables. As a result of that save_hist_vars() was not called to add
the trigger to trace_array->hist_vars. Later on when we attempted to
remove the first histogram find_any_var_ref() failed to detect it is
being used because it did not find the second trigger in hist_vars list.
With this change we wait until trigger actions are created so we can take
into consideration if hist trigger has variable references. Also, now we
check the return value of save_hist_vars() and fail trigger creation if
save_hist_vars() fails.
Link: https://lore.kernel.org/linux-trace-kernel/20230712223021.636335-1-mkhalfella@purestorage.com
Cc: stable@vger.kernel.org
Fixes: 067fe038e7 ("tracing: Add variable reference handling to hist triggers")
Signed-off-by: Mohamed Khalfella <mkhalfella@purestorage.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The stack_trace event is an event created by the tracing subsystem to
store stack traces. It originally just contained a hard coded array of 8
words to hold the stack, and a "size" to know how many entries are there.
This is exported to user space as:
name: kernel_stack
ID: 4
format:
field:unsigned short common_type; offset:0; size:2; signed:0;
field:unsigned char common_flags; offset:2; size:1; signed:0;
field:unsigned char common_preempt_count; offset:3; size:1; signed:0;
field:int common_pid; offset:4; size:4; signed:1;
field:int size; offset:8; size:4; signed:1;
field:unsigned long caller[8]; offset:16; size:64; signed:0;
print fmt: "\t=> %ps\n\t=> %ps\n\t=> %ps\n" "\t=> %ps\n\t=> %ps\n\t=> %ps\n" "\t=> %ps\n\t=> %ps\n",i
(void *)REC->caller[0], (void *)REC->caller[1], (void *)REC->caller[2],
(void *)REC->caller[3], (void *)REC->caller[4], (void *)REC->caller[5],
(void *)REC->caller[6], (void *)REC->caller[7]
Where the user space tracers could parse the stack. The library was
updated for this specific event to only look at the size, and not the
array. But some older users still look at the array (note, the older code
still checks to make sure the array fits inside the event that it read.
That is, if only 4 words were saved, the parser would not read the fifth
word because it will see that it was outside of the event size).
This event was changed a while ago to be more dynamic, and would save a
full stack even if it was greater than 8 words. It does this by simply
allocating more ring buffer to hold the extra words. Then it copies in the
stack via:
memcpy(&entry->caller, fstack->calls, size);
As the entry is struct stack_entry, that is created by a macro to both
create the structure and export this to user space, it still had the caller
field of entry defined as: unsigned long caller[8].
When the stack is greater than 8, the FORTIFY_SOURCE code notices that the
amount being copied is greater than the source array and complains about
it. It has no idea that the source is pointing to the ring buffer with the
required allocation.
To hide this from the FORTIFY_SOURCE logic, pointer arithmetic is used:
ptr = ring_buffer_event_data(event);
entry = ptr;
ptr += offsetof(typeof(*entry), caller);
memcpy(ptr, fstack->calls, size);
Link: https://lore.kernel.org/all/20230612160748.4082850-1-svens@linux.ibm.com/
Link: https://lore.kernel.org/linux-trace-kernel/20230712105235.5fc441aa@gandalf.local.home
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Reported-by: Sven Schnelle <svens@linux.ibm.com>
Tested-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
As comments in ftrace_process_locs(), there may be NULL pointers in
mcount_loc section:
> Some architecture linkers will pad between
> the different mcount_loc sections of different
> object files to satisfy alignments.
> Skip any NULL pointers.
After commit 20e5227e9f ("ftrace: allow NULL pointers in mcount_loc"),
NULL pointers will be accounted when allocating ftrace pages but skipped
before adding into ftrace pages, this may result in some pages not being
used. Then after commit 706c81f87f ("ftrace: Remove extra helper
functions"), warning may occur at:
WARN_ON(pg->next);
To fix it, only warn for case that no pointers skipped but pages not used
up, then free those unused pages after releasing ftrace_lock.
Link: https://lore.kernel.org/linux-trace-kernel/20230712060452.3175675-1-zhengyejian1@huawei.com
Cc: stable@vger.kernel.org
Fixes: 706c81f87f ("ftrace: Remove extra helper functions")
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
- Fix fprobe's rethook release timing issue(1). Release rethook after
ftrace_ops is unregistered so that the rethook is not accessed after
free.
- Fix fprobe's rethook access timing issue(2). Stop rethook before
ftrace_ops is unregistered so that the rethook is NOT keep using
after exiting the unregister_fprobe().
- Fix eprobe cleanup logic. If it attaches to multiple events and failes
to enable one of them, rollback all enabled events correctly.
- Fix fprobe to unlock ftrace recursion lock correctly when it missed
by another running kprobe.
- Cleanup kprobe to remove unnecessary NULL.
- Cleanup kprobe to remove unnecessary 0 initializations.
-----BEGIN PGP SIGNATURE-----
iQFPBAABCgA5FiEEh7BulGwFlgAOi5DV2/sHvwUrPxsFAmStawEbHG1hc2FtaS5o
aXJhbWF0c3VAZ21haWwuY29tAAoJENv7B78FKz8bMBkIAJYun4zeXsFeUUNVZMP8
UlcyBt/uiB1Ch/t1T1wc55plWIDAvUfN+FEltwhb6MJsQgWEjKJxNcH+oquQeqSH
OkUvV6a8BR73FWbCt1Tm2MQKEG1RHC1R4JCj5GCzP93rQSCnmvr0c1yb6+JKQRx4
aPgWUjDm9vhYlOXS6heHo0hf0MbXDl1kqHjvMU2MXUMk7NtQ2JEo1Whikf7Drl6D
ufNqV54GmtuJhgIWAqSk+qWresRvXy0/5i4ONK1Kmq+pdhssjZ4KFsWFQTIkQzdU
nP8t2EfOp3aglx7ANvEJ+COfFNi0aMnHVBo7BbzsOy7Cq7IZTfD6zOTYSfylGGdA
Uw4=
=RBbc
-----END PGP SIGNATURE-----
Merge tag 'probes-fixes-v6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull probes fixes from Masami Hiramatsu:
- Fix fprobe's rethook release issues:
- Release rethook after ftrace_ops is unregistered so that the
rethook is not accessed after free.
- Stop rethook before ftrace_ops is unregistered so that the
rethook is NOT used after exiting unregister_fprobe()
- Fix eprobe cleanup logic. If it attaches to multiple events and
failes to enable one of them, rollback all enabled events correctly.
- Fix fprobe to unlock ftrace recursion lock correctly when it missed
by another running kprobe.
- Cleanup kprobe to remove unnecessary NULL.
- Cleanup kprobe to remove unnecessary 0 initializations.
* tag 'probes-fixes-v6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
fprobe: Ensure running fprobe_exit_handler() finished before calling rethook_free()
kernel: kprobes: Remove unnecessary ‘0’ values
kprobes: Remove unnecessary ‘NULL’ values from correct_ret_addr
fprobe: add unlock to match a succeeded ftrace_test_recursion_trylock
kernel/trace: Fix cleanup logic of enable_trace_eprobe
fprobe: Release rethook after the ftrace_ops is unregistered
Soft lockup occurs when reading file 'trace_pipe':
watchdog: BUG: soft lockup - CPU#6 stuck for 22s! [cat:4488]
[...]
RIP: 0010:ring_buffer_empty_cpu+0xed/0x170
RSP: 0018:ffff88810dd6fc48 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000246 RCX: ffffffff93d1aaeb
RDX: ffff88810a280040 RSI: 0000000000000008 RDI: ffff88811164b218
RBP: ffff88811164b218 R08: 0000000000000000 R09: ffff88815156600f
R10: ffffed102a2acc01 R11: 0000000000000001 R12: 0000000051651901
R13: 0000000000000000 R14: ffff888115e49500 R15: 0000000000000000
[...]
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8d853c2000 CR3: 000000010dcd8000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__find_next_entry+0x1a8/0x4b0
? peek_next_entry+0x250/0x250
? down_write+0xa5/0x120
? down_write_killable+0x130/0x130
trace_find_next_entry_inc+0x3b/0x1d0
tracing_read_pipe+0x423/0xae0
? tracing_splice_read_pipe+0xcb0/0xcb0
vfs_read+0x16b/0x490
ksys_read+0x105/0x210
? __ia32_sys_pwrite64+0x200/0x200
? switch_fpu_return+0x108/0x220
do_syscall_64+0x33/0x40
entry_SYSCALL_64_after_hwframe+0x61/0xc6
Through the vmcore, I found it's because in tracing_read_pipe(),
ring_buffer_empty_cpu() found some buffer is not empty but then it
cannot read anything due to "rb_num_of_entries() == 0" always true,
Then it infinitely loop the procedure due to user buffer not been
filled, see following code path:
tracing_read_pipe() {
... ...
waitagain:
tracing_wait_pipe() // 1. find non-empty buffer here
trace_find_next_entry_inc() // 2. loop here try to find an entry
__find_next_entry()
ring_buffer_empty_cpu(); // 3. find non-empty buffer
peek_next_entry() // 4. but peek always return NULL
ring_buffer_peek()
rb_buffer_peek()
rb_get_reader_page()
// 5. because rb_num_of_entries() == 0 always true here
// then return NULL
// 6. user buffer not been filled so goto 'waitgain'
// and eventually leads to an deadloop in kernel!!!
}
By some analyzing, I found that when resetting ringbuffer, the 'entries'
of its pages are not all cleared (see rb_reset_cpu()). Then when reducing
the ringbuffer, and if some reduced pages exist dirty 'entries' data, they
will be added into 'cpu_buffer->overrun' (see rb_remove_pages()), which
cause wrong 'overrun' count and eventually cause the deadloop issue.
To fix it, we need to clear every pages in rb_reset_cpu().
Link: https://lore.kernel.org/linux-trace-kernel/20230708225144.3785600-1-zhengyejian1@huawei.com
Cc: stable@vger.kernel.org
Fixes: a5fb833172 ("ring-buffer: Fix uninitialized read_stamp")
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
These are all tracing W=1 warnings in arm64 allmodconfig about missing
prototypes:
kernel/trace/trace_kprobe_selftest.c:7:5: error: no previous prototype for 'kprobe_trace_selftest_target' [-Werror=missing-pro
totypes]
kernel/trace/ftrace.c:329:5: error: no previous prototype for '__register_ftrace_function' [-Werror=missing-prototypes]
kernel/trace/ftrace.c:372:5: error: no previous prototype for '__unregister_ftrace_function' [-Werror=missing-prototypes]
kernel/trace/ftrace.c:4130:15: error: no previous prototype for 'arch_ftrace_match_adjust' [-Werror=missing-prototypes]
kernel/trace/fgraph.c:243:15: error: no previous prototype for 'ftrace_return_to_handler' [-Werror=missing-prototypes]
kernel/trace/fgraph.c:358:6: error: no previous prototype for 'ftrace_graph_sleep_time_control' [-Werror=missing-prototypes]
arch/arm64/kernel/ftrace.c:460:6: error: no previous prototype for 'prepare_ftrace_return' [-Werror=missing-prototypes]
arch/arm64/kernel/ptrace.c:2172:5: error: no previous prototype for 'syscall_trace_enter' [-Werror=missing-prototypes]
arch/arm64/kernel/ptrace.c:2195:6: error: no previous prototype for 'syscall_trace_exit' [-Werror=missing-prototypes]
Move the declarations to an appropriate header where they can be seen
by the caller and callee, and make sure the headers are included where
needed.
Link: https://lore.kernel.org/linux-trace-kernel/20230517125215.930689-1-arnd@kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Florent Revest <revest@chromium.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
[ Fixed ftrace_return_to_handler() to handle CONFIG_HAVE_FUNCTION_GRAPH_RETVAL case ]
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When users register an event the name of the event and it's argument are
checked to ensure they match if the event already exists. Normally all
arguments are in the form of "type name", except for when the type
starts with "struct ". In those cases, the size of the struct is passed
in addition to the name, IE: "struct my_struct a 20" for an argument
that is of type "struct my_struct" with a field name of "a" and has the
size of 20 bytes.
The current code does not honor the above case properly when comparing
a match. This causes the event register to fail even when the same
string was used for events that contain a struct argument within them.
The example above "struct my_struct a 20" generates a match string of
"struct my_struct a" omitting the size field.
Add the struct size of the existing field when generating a comparison
string for a struct field to ensure proper match checking.
Link: https://lkml.kernel.org/r/20230629235049.581-2-beaub@linux.microsoft.com
Cc: stable@vger.kernel.org
Fixes: e6f89a1498 ("tracing/user_events: Ensure user provided strings are safely formatted")
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Ensure running fprobe_exit_handler() has finished before
calling rethook_free() in the unregister_fprobe() so that caller can free
the fprobe right after unregister_fprobe().
unregister_fprobe() ensured that all running fprobe_entry/exit_handler()
have finished by calling unregister_ftrace_function() which synchronizes
RCU. But commit 5f81018753 ("fprobe: Release rethook after the ftrace_ops
is unregistered") changed to call rethook_free() after
unregister_ftrace_function(). So call rethook_stop() to make rethook
disabled before unregister_ftrace_function() and ensure it again.
Here is the possible code flow that can call the exit handler after
unregister_fprobe().
------
CPU1 CPU2
call unregister_fprobe(fp)
...
__fprobe_handler()
rethook_hook() on probed function
unregister_ftrace_function()
return from probed function
rethook hooks
find rh->handler == fprobe_exit_handler
call fprobe_exit_handler()
rethook_free():
set rh->handler = NULL;
return from unreigster_fprobe;
call fp->exit_handler() <- (*)
------
(*) At this point, the exit handler is called after returning from
unregister_fprobe().
This fixes it as following;
------
CPU1 CPU2
call unregister_fprobe()
...
rethook_stop():
set rh->handler = NULL;
__fprobe_handler()
rethook_hook() on probed function
unregister_ftrace_function()
return from probed function
rethook hooks
find rh->handler == NULL
return from rethook
rethook_free()
return from unreigster_fprobe;
------
Link: https://lore.kernel.org/all/168873859949.156157.13039240432299335849.stgit@devnote2/
Fixes: 5f81018753 ("fprobe: Release rethook after the ftrace_ops is unregistered")
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The enable_trace_eprobe() function enables all event probes, attached
to given trace probe. If an error occurs in enabling one of the event
probes, all others should be roll backed. There is a bug in that roll
back logic - instead of all event probes, only the failed one is
disabled.
Link: https://lore.kernel.org/all/20230703042853.1427493-1-tz.stoyanov@gmail.com/
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Fixes: 7491e2c442 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
- Fix bad git merge of #endif in arm64 code
A merge of the arm64 tree caused #endif to go into the wrong place
- Fix crash on lseek of write access to tracefs/error_log
Opening error_log as write only, and then doing an lseek() causes
a kernel panic, because the lseek() handle expects a "seq_file"
to exist (which is not done on write only opens). Use tracing_lseek()
that tests for this instead of calling the default seq lseek handler.
- Check for negative instead of -E2BIG for error on strscpy() returns
Instead of testing for -E2BIG from strscpy(), to be more robust,
check for less than zero, which will make sure it catches any error
that strscpy() may someday return.
-----BEGIN PGP SIGNATURE-----
iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCZKbQUhQccm9zdGVkdEBn
b29kbWlzLm9yZwAKCRAp5XQQmuv6qpWaAP9zQ1eLQSfMt0dHH01OBSJvc2mMd4QJ
VZtWZ+xTSvk+4gD/axDzDS7Qisfrrli+1oQSPwVik2SXiz0SPJqJ25m9zw4=
=xMlg
-----END PGP SIGNATURE-----
Merge tag 'trace-v6.5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:
- Fix bad git merge of #endif in arm64 code
A merge of the arm64 tree caused #endif to go into the wrong place
- Fix crash on lseek of write access to tracefs/error_log
Opening error_log as write only, and then doing an lseek() causes a
kernel panic, because the lseek() handle expects a "seq_file" to
exist (which is not done on write only opens). Use tracing_lseek()
that tests for this instead of calling the default seq lseek handler.
- Check for negative instead of -E2BIG for error on strscpy() returns
Instead of testing for -E2BIG from strscpy(), to be more robust,
check for less than zero, which will make sure it catches any error
that strscpy() may someday return.
* tag 'trace-v6.5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing/boot: Test strscpy() against less than zero for error
arm64: ftrace: fix build error with CONFIG_FUNCTION_GRAPH_TRACER=n
tracing: Fix null pointer dereference in tracing_err_log_open()
Instead of checking for -E2BIG, it is better to just check for less than
zero of strscpy() for error. Testing for -E2BIG is not very robust, and
the calling code does not really care about the error code, just that
there was an error.
One of the updates to convert strlcpy() to strscpy() had a v2 version
that changed the test from testing against -E2BIG to less than zero, but I
took the v1 version that still tested for -E2BIG.
Link: https://lore.kernel.org/linux-trace-kernel/20230615180420.400769-1-azeemshaikh38@gmail.com/
Link: https://lore.kernel.org/linux-trace-kernel/20230704100807.707d1605@rorschach.local.home
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Azeem Shaikh <azeemshaikh38@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Fix an issue in function 'tracing_err_log_open'.
The function doesn't call 'seq_open' if the file is opened only with
write permissions, which results in 'file->private_data' being left as null.
If we then use 'lseek' on that opened file, 'seq_lseek' dereferences
'file->private_data' in 'mutex_lock(&m->lock)', resulting in a kernel panic.
Writing to this node requires root privileges, therefore this bug
has very little security impact.
Tracefs node: /sys/kernel/tracing/error_log
Example Kernel panic:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000038
Call trace:
mutex_lock+0x30/0x110
seq_lseek+0x34/0xb8
__arm64_sys_lseek+0x6c/0xb8
invoke_syscall+0x58/0x13c
el0_svc_common+0xc4/0x10c
do_el0_svc+0x24/0x98
el0_svc+0x24/0x88
el0t_64_sync_handler+0x84/0xe4
el0t_64_sync+0x1b4/0x1b8
Code: d503201f aa0803e0 aa1f03e1 aa0103e9 (c8e97d02)
---[ end trace 561d1b49c12cf8a5 ]---
Kernel panic - not syncing: Oops: Fatal exception
Link: https://lore.kernel.org/linux-trace-kernel/20230703155237eucms1p4dfb6a19caa14c79eb6c823d127b39024@eucms1p4
Link: https://lore.kernel.org/linux-trace-kernel/20230704102706eucms1p30d7ecdcc287f46ad67679fc8491b2e0f@eucms1p3
Cc: stable@vger.kernel.org
Fixes: 8a062902be ("tracing: Add tracing error log")
Signed-off-by: Mateusz Stachyra <m.stachyra@samsung.com>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
- fprobe: Pass return address to the fprobe entry/exit callbacks so that
the callbacks don't need to analyze pt_regs/stack to find the function
return address.
- kprobe events: cleanup usage of TPARG_FL_FENTRY and TPARG_FL_RETURN
flags so that those are not set at once.
- fprobe events:
. Add a new fprobe events for tracing arbitrary function entry and
exit as a trace event.
. Add a new tracepoint events for tracing raw tracepoint as a trace
event. This allows user to trace non user-exposed tracepoints.
. Move eprobe's event parser code into probe event common file.
. Introduce BTF (BPF type format) support to kernel probe (kprobe,
fprobe and tracepoint probe) events so that user can specify traced
function arguments by name. This also applies the type of argument
when fetching the argument.
. Introduce '$arg*' wildcard support if BTF is available. This expands
the '$arg*' meta argument to all function argument automatically.
. Check the return value types by BTF. If the function returns 'void',
'$retval' is rejected.
. Add some selftest script for fprobe events, tracepoint events and
BTF support.
. Update documentation about the fprobe events.
. Some fixes for above features, document and selftests.
- selftests for ftrace (except for new fprobe events):
. Add a test case for multiple consecutive probes in a function which
checks if ftrace based kprobe, optimized kprobe and normal kprobe
can be defined in the same target function.
. Add a test case for optimized probe, which checks whether kprobe
can be optimized or not.
-----BEGIN PGP SIGNATURE-----
iQEzBAABCgAdFiEEh7BulGwFlgAOi5DV2/sHvwUrPxsFAmSa+9MACgkQ2/sHvwUr
PxsmOAgAmUOIWtvH5py7AZpIRhCj8B18F6KnT7w2hByCsRxf7SaCqMhpBCk9VnYv
9fJFBHpvYRJEmpHoH3o2ET5AGfKVNac9z96AGI2qJ4ECWITd6I5+WfTdZ5ueVn2d
f6DQ10mHXDHSMFbuqfYWSHtkeivJpWpUNHhwzPb4doNOe06bZNfVuSgnksFg1at5
kq16HbvGnhPzdO4YHmvqwjmRHr5/nCI1KDE9xIBcqNtWFbiRigC11zaZEUkLX+vT
F63ShyfCK718AiwDfnjXpGkXAiVOZuAIR8RELaSqQ92YHCFKq5k9K4++WllPR5f9
AxjVultFDiCd4oSPgYpQkjuZdFq9NA==
=IhmY
-----END PGP SIGNATURE-----
Merge tag 'probes-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull probes updates from Masami Hiramatsu:
- fprobe: Pass return address to the fprobe entry/exit callbacks so
that the callbacks don't need to analyze pt_regs/stack to find the
function return address.
- kprobe events: cleanup usage of TPARG_FL_FENTRY and TPARG_FL_RETURN
flags so that those are not set at once.
- fprobe events:
- Add a new fprobe events for tracing arbitrary function entry and
exit as a trace event.
- Add a new tracepoint events for tracing raw tracepoint as a
trace event. This allows user to trace non user-exposed
tracepoints.
- Move eprobe's event parser code into probe event common file.
- Introduce BTF (BPF type format) support to kernel probe (kprobe,
fprobe and tracepoint probe) events so that user can specify
traced function arguments by name. This also applies the type of
argument when fetching the argument.
- Introduce '$arg*' wildcard support if BTF is available. This
expands the '$arg*' meta argument to all function argument
automatically.
- Check the return value types by BTF. If the function returns
'void', '$retval' is rejected.
- Add some selftest script for fprobe events, tracepoint events
and BTF support.
- Update documentation about the fprobe events.
- Some fixes for above features, document and selftests.
- selftests for ftrace (in addition to the new fprobe events):
- Add a test case for multiple consecutive probes in a function
which checks if ftrace based kprobe, optimized kprobe and normal
kprobe can be defined in the same target function.
- Add a test case for optimized probe, which checks whether kprobe
can be optimized or not.
* tag 'probes-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing/probes: Fix tracepoint event with $arg* to fetch correct argument
Documentation: Fix typo of reference file name
tracing/probes: Fix to return NULL and keep using current argc
selftests/ftrace: Add new test case which checks for optimized probes
selftests/ftrace: Add new test case which adds multiple consecutive probes in a function
Documentation: tracing/probes: Add fprobe event tracing document
selftests/ftrace: Add BTF arguments test cases
selftests/ftrace: Add tracepoint probe test case
tracing/probes: Add BTF retval type support
tracing/probes: Add $arg* meta argument for all function args
tracing/probes: Support function parameters if BTF is available
tracing/probes: Move event parameter fetching code to common parser
tracing/probes: Add tracepoint support on fprobe_events
selftests/ftrace: Add fprobe related testcases
tracing/probes: Add fprobe events for tracing function entry and exit.
tracing/probes: Avoid setting TPARG_FL_FENTRY and TPARG_FL_RETURN
fprobe: Pass return address to the handlers
- Add new feature to have function graph tracer record the return value.
Adds a new option: funcgraph-retval ; when set, will show the return
value of a function in the function graph tracer.
- Also add the option: funcgraph-retval-hex where if it is not set, and
the return value is an error code, then it will return the decimal of
the error code, otherwise it still reports the hex value.
- Add the file /sys/kernel/tracing/osnoise/per_cpu/cpu<cpu>/timerlat_fd
That when a application opens it, it becomes the task that the timer lat
tracer traces. The application can also read this file to find out how
it's being interrupted.
- Add the file /sys/kernel/tracing/available_filter_functions_addrs
that works just the same as available_filter_functions but also shows
the addresses of the functions like kallsyms, except that it gives the
address of where the fentry/mcount jump/nop is. This is used by BPF to
make it easier to attach BPF programs to ftrace hooks.
- Replace strlcpy with strscpy in the tracing boot code.
-----BEGIN PGP SIGNATURE-----
iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCZJy6ixQccm9zdGVkdEBn
b29kbWlzLm9yZwAKCRAp5XQQmuv6qnzRAPsEI2YgjaJSHnuPoGRHbrNil6pq66wY
LYaLizGI4Jv9BwEAqdSdcYcMiWo1SFBAO8QxEDM++BX3zrRyVgW8ahaTNgs=
=TF0C
-----END PGP SIGNATURE-----
Merge tag 'trace-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing updates from Steven Rostedt:
- Add new feature to have function graph tracer record the return
value. Adds a new option: funcgraph-retval ; when set, will show the
return value of a function in the function graph tracer.
- Also add the option: funcgraph-retval-hex where if it is not set, and
the return value is an error code, then it will return the decimal of
the error code, otherwise it still reports the hex value.
- Add the file /sys/kernel/tracing/osnoise/per_cpu/cpu<cpu>/timerlat_fd
That when a application opens it, it becomes the task that the timer
lat tracer traces. The application can also read this file to find
out how it's being interrupted.
- Add the file /sys/kernel/tracing/available_filter_functions_addrs
that works just the same as available_filter_functions but also shows
the addresses of the functions like kallsyms, except that it gives
the address of where the fentry/mcount jump/nop is. This is used by
BPF to make it easier to attach BPF programs to ftrace hooks.
- Replace strlcpy with strscpy in the tracing boot code.
* tag 'trace-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: Fix warnings when building htmldocs for function graph retval
riscv: ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL
tracing/boot: Replace strlcpy with strscpy
tracing/timerlat: Add user-space interface
tracing/osnoise: Skip running osnoise if all instances are off
tracing/osnoise: Switch from PF_NO_SETAFFINITY to migrate_disable
ftrace: Show all functions with addresses in available_filter_functions_addrs
selftests/ftrace: Add funcgraph-retval test case
LoongArch: ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL
x86/ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL
arm64: ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL
tracing: Add documentation for funcgraph-retval and funcgraph-retval-hex
function_graph: Support recording and printing the return value of function
fgraph: Add declaration of "struct fgraph_ret_regs"