01 Dec, 2020
1 commit
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my_tramp[12]? are declared as global functions in C, but they are not
marked global in the inline assembly definition. This mismatch confuses
Clang's Control-Flow Integrity checking. Fix the definitions by adding
.globl.Link: https://lkml.kernel.org/r/20201113183414.1446671-1-samitolvanen@google.com
Fixes: 9d907f1ae80b8 ("ftrace/samples: Add a sample module that implements modify_ftrace_direct()")
Reviewed-by: Kees Cook
Signed-off-by: Sami Tolvanen
Signed-off-by: Steven Rostedt (VMware)
17 Jun, 2020
2 commits
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Remove trace_array 'sample-instance' if kthread_run fails
in sample_trace_array_init().Link: https://lkml.kernel.org/r/20200609135200.2206726-1-wangkefeng.wang@huawei.com
Cc: stable@vger.kernel.org
Fixes: 89ed42495ef4a ("tracing: Sample module to demonstrate kernel access to Ftrace instances.")
Reviewed-by: Divya Indi
Signed-off-by: Kefeng Wang
Signed-off-by: Steven Rostedt (VMware) -
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:935
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 0, name: swapper/5
1 lock held by swapper/5/0:
#0: ffff80001002bd90 (samples/ftrace/sample-trace-array.c:38){+.-.}-{0:0}, at: call_timer_fn+0x8/0x3e0
CPU: 5 PID: 0 Comm: swapper/5 Not tainted 5.7.0+ #8
Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015
Call trace:
dump_backtrace+0x0/0x1a0
show_stack+0x20/0x30
dump_stack+0xe4/0x150
___might_sleep+0x160/0x200
__might_sleep+0x58/0x90
__mutex_lock+0x64/0x948
mutex_lock_nested+0x3c/0x58
__ftrace_set_clr_event+0x44/0x88
trace_array_set_clr_event+0x24/0x38
mytimer_handler+0x34/0x40 [sample_trace_array]mutex_lock() will be called in interrupt context, using workqueue to fix it.
Link: https://lkml.kernel.org/r/20200610011244.2209486-1-wangkefeng.wang@huawei.com
Cc: stable@vger.kernel.org
Fixes: 89ed42495ef4 ("tracing: Sample module to demonstrate kernel access to Ftrace instances.")
Reviewed-by: Divya Indi
Signed-off-by: Kefeng Wang
Signed-off-by: Steven Rostedt (VMware)
20 May, 2020
1 commit
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Enable objtool coverage for the sample ftrace modules by adding ELF
annotations to the asm trampoline functions.samples/ftrace/ftrace-direct.o: warning: objtool: .text+0x0: unreachable instruction
samples/ftrace/ftrace-direct-modify.o: warning: objtool: .text+0x0: unreachable instruction
samples/ftrace/ftrace-direct-too.o: warning: objtool: .text+0x0: unreachable instructionReported-by: Randy Dunlap
Signed-off-by: Josh Poimboeuf
23 Nov, 2019
1 commit
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This is a sample module to demonstrate the use of the newly introduced and
exported APIs to access Ftrace instances from within the kernel.Newly introduced APIs used here -
1. Create/Lookup a trace array with the given name.
struct trace_array *trace_array_get_by_name(const char *name)2. Destroy/Remove a trace array.
int trace_array_destroy(struct trace_array *tr)4. Enable/Disable trace events:
int trace_array_set_clr_event(struct trace_array *tr, const char *system,
const char *event, bool enable);Exported APIs -
1. trace_printk equivalent for instances.
int trace_array_printk(struct trace_array *tr,
unsigned long ip, const char *fmt, ...);2. Helper function.
void trace_printk_init_buffers(void);3. To decrement the reference counter.
void trace_array_put(struct trace_array *tr)Sample output(contents of /sys/kernel/tracing/instances/sample-instance)
NOTE: Tracing disabled after ~5 sec)_-----=> irqs-off
/ _----=> need-resched
| / _---=> hardirq/softirq
|| / _--=> preempt-depth
||| / delay
TASK-PID CPU# |||| TIMESTAMP FUNCTION
| | | |||| | |
sample-instance-1452 [002] .... 49.430948: simple_thread: trace_array_printk: count=0
sample-instance-1452 [002] .... 49.430951: sample_event: count value=0 at jiffies=4294716608
sample-instance-1452 [002] .... 50.454847: simple_thread: trace_array_printk: count=1
sample-instance-1452 [002] .... 50.454849: sample_event: count value=1 at jiffies=4294717632
sample-instance-1452 [002] .... 51.478748: simple_thread: trace_array_printk: count=2
sample-instance-1452 [002] .... 51.478750: sample_event: count value=2 at jiffies=4294718656
sample-instance-1452 [002] .... 52.502652: simple_thread: trace_array_printk: count=3
sample-instance-1452 [002] .... 52.502655: sample_event: count value=3 at jiffies=4294719680
sample-instance-1452 [002] .... 53.526533: simple_thread: trace_array_printk: count=4
sample-instance-1452 [002] .... 53.526535: sample_event: count value=4 at jiffies=4294720704
sample-instance-1452 [002] .... 54.550438: simple_thread: trace_array_printk: count=5
sample-instance-1452 [002] .... 55.574336: simple_thread: trace_array_printk: count=6Link: http://lkml.kernel.org/r/1574276919-11119-3-git-send-email-divya.indi@oracle.com
Reviewed-by: Aruna Ramakrishna
Signed-off-by: Divya Indi
[ Moved to samples/ftrace ]
Signed-off-by: Steven Rostedt (VMware)
16 Nov, 2019
1 commit
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There is a spelling mistake in a trace_printk message. As well as in
the selftests that search for this string.Link: http://lkml.kernel.org/r/20191115085938.38947-1-colin.king@canonical.com
Link: http://lkml.kernel.org/r/20191115090356.39572-1-colin.king@canonical.comSigned-off-by: Colin Ian King
Signed-off-by: Steven Rostedt (VMware)
15 Nov, 2019
1 commit
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Add a sample module that tests modify_ftrace_direct(), and this can be used
by the selftests as well.Signed-off-by: Steven Rostedt (VMware)
13 Nov, 2019
2 commits
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Add another module sample that registers a direct trampoline to a function
via register_ftrace_direct(). Having another module that does this allows to
test the use case of multiple direct callers registered, as more than one
direct caller goes into another path, and is needed to perform proper
testing of the register_ftrace_direct() call.Signed-off-by: Steven Rostedt (VMware)
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Add a sample module that shows a simple use case for
regsiter_ftrace_direct(), and how to use it.Signed-off-by: Steven Rostedt (VMware)