Commit Graph

15 Commits

Author SHA1 Message Date
Heiko Carstens
890e3dc8bb ftrace/samples: add s390 support for ftrace direct multi sample
Add s390 architecture support for the ftrace direct multi sample.
See commit 5fae941b9a ("ftrace/samples: Add multi direct interface
test module") for further details.

Link: https://lore.kernel.org/r/20211115195614.3173346-3-hca@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-11-18 17:50:54 +01:00
Heiko Carstens
503e451084 ftrace/samples: add missing Kconfig option for ftrace direct multi sample
Currently it is not possible to build the ftrace direct multi example
anymore due to broken config dependencies. Fix this by adding
SAMPLE_FTRACE_DIRECT_MULTI config option.

This broke when merging s390-5.16-1 due to an incorrect merge conflict
resolution proposed by me.

Also rename SAMPLE_FTRACE_MULTI_DIRECT to SAMPLE_FTRACE_DIRECT_MULTI
so it matches the module name.

Fixes: 0b707e572a ("Merge tag 's390-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux")
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20211115195614.3173346-2-hca@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-11-18 17:50:54 +01:00
Linus Torvalds
0b707e572a s390 updates for the 5.16 merge window
- Add support for ftrace with direct call and ftrace direct call samples.
 
 - Add support for kernel command lines longer than current 896 bytes and
   make its length configurable.
 
 - Add support for BEAR enhancement facility to improve last breaking
   event instruction tracking.
 
 - Add kprobes sanity checks and testcases to prevent kprobe in the mid
   of an instruction.
 
 - Allow concurrent access to /dev/hwc for the CPUMF users.
 
 - Various ftrace / jump label improvements.
 
 - Convert unwinder tests to KUnit.
 
 - Add s390_iommu_aperture kernel parameter to tweak the limits on
   concurrently usable DMA mappings.
 
 - Add ap.useirq AP module option which can be used to disable interrupt
   use.
 
 - Add add_disk() error handling support to block device drivers.
 
 - Drop arch specific and use generic implementation of strlcpy and strrchr.
 
 - Several __pa/__va usages fixes.
 
 - Various cio, crypto, pci, kernel doc and other small fixes and
   improvements all over the code.
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Merge tag 's390-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Vasily Gorbik:

 - Add support for ftrace with direct call and ftrace direct call
   samples.

 - Add support for kernel command lines longer than current 896 bytes
   and make its length configurable.

 - Add support for BEAR enhancement facility to improve last breaking
   event instruction tracking.

 - Add kprobes sanity checks and testcases to prevent kprobe in the mid
   of an instruction.

 - Allow concurrent access to /dev/hwc for the CPUMF users.

 - Various ftrace / jump label improvements.

 - Convert unwinder tests to KUnit.

 - Add s390_iommu_aperture kernel parameter to tweak the limits on
   concurrently usable DMA mappings.

 - Add ap.useirq AP module option which can be used to disable interrupt
   use.

 - Add add_disk() error handling support to block device drivers.

 - Drop arch specific and use generic implementation of strlcpy and
   strrchr.

 - Several __pa/__va usages fixes.

 - Various cio, crypto, pci, kernel doc and other small fixes and
   improvements all over the code.

[ Merge fixup as per https://lore.kernel.org/all/YXAqZ%2FEszRisunQw@osiris/ ]

* tag 's390-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (63 commits)
  s390: make command line configurable
  s390: support command lines longer than 896 bytes
  s390/kexec_file: move kernel image size check
  s390/pci: add s390_iommu_aperture kernel parameter
  s390/spinlock: remove incorrect kernel doc indicator
  s390/string: use generic strlcpy
  s390/string: use generic strrchr
  s390/ap: function rework based on compiler warning
  s390/cio: make ccw_device_dma_* more robust
  s390/vfio-ap: s390/crypto: fix all kernel-doc warnings
  s390/hmcdrv: fix kernel doc comments
  s390/ap: new module option ap.useirq
  s390/cpumf: Allow multiple processes to access /dev/hwc
  s390/bitops: return true/false (not 1/0) from bool functions
  s390: add support for BEAR enhancement facility
  s390: introduce nospec_uses_trampoline()
  s390: rename last_break to pgm_last_break
  s390/ptrace: add last_break member to pt_regs
  s390/sclp: sort out physical vs virtual pointers usage
  s390/setup: convert start and end initrd pointers to virtual
  ...
2021-11-06 14:48:06 -07:00
Jiri Olsa
67d4f6e3bf ftrace/samples: Add missing prototype for my_direct_func
There's compilation fail reported kernel test robot for W=1 build:

  >> samples/ftrace/ftrace-direct-multi.c:8:6: warning: no previous
  prototype for function 'my_direct_func' [-Wmissing-prototypes]
     void my_direct_func(unsigned long ip)

The inlined assembly is used outside function, so we can't make
my_direct_func static and pass it as asm input argument.

However my_tramp is already extern so I think there's no problem
keeping my_direct_func extern as well and just add its prototype.

Link: https://lkml.kernel.org/r/20211101153907.377668-1-jolsa@kernel.org

Reported-by: kernel test robot <lkp@intel.com>
Fixes: 5fae941b9a ("ftrace/samples: Add multi direct interface test module")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-11-01 20:56:51 -04:00
Jiri Olsa
5fae941b9a ftrace/samples: Add multi direct interface test module
Adding simple module that uses multi direct interface:

  register_ftrace_direct_multi
  unregister_ftrace_direct_multi

The init function registers trampoline for 2 functions,
and exit function unregisters them.

Link: https://lkml.kernel.org/r/20211008091336.33616-9-jolsa@kernel.org

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-21 14:19:00 -04:00
Heiko Carstens
1254cfbc5f samples: add s390 support for ftrace direct call samples
Add s390 support for ftrace direct call samples, which also enables
ftrace direct call selftests within ftrace selftests.

Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20211012133802.2460757-5-hca@linux.ibm.com
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-10-19 15:39:54 +02:00
Sami Tolvanen
983df5f269 samples/ftrace: Mark my_tramp[12]? global
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: 9d907f1ae8 ("ftrace/samples: Add a sample module that implements modify_ftrace_direct()")
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-30 21:42:48 -05:00
Kefeng Wang
9fbc01cdba sample-trace-array: Remove trace_array 'sample-instance'
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: 89ed42495e ("tracing: Sample module to demonstrate kernel access to Ftrace instances.")
Reviewed-by: Divya Indi <divya.indi@oracle.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-16 21:21:02 -04:00
Kefeng Wang
e9b7b1c0c1 sample-trace-array: Fix sleeping function called from invalid context
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: 89ed42495e ("tracing: Sample module to demonstrate kernel access to Ftrace instances.")
Reviewed-by: Divya Indi <divya.indi@oracle.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-16 21:21:02 -04:00
Josh Poimboeuf
9d907f1ae8 samples/ftrace: Fix asm function ELF annotations
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 instruction

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
2020-05-20 08:30:43 -05:00
Divya Indi
89ed42495e tracing: Sample module to demonstrate kernel access to Ftrace instances.
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=6

Link: http://lkml.kernel.org/r/1574276919-11119-3-git-send-email-divya.indi@oracle.com

Reviewed-by: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
Signed-off-by: Divya Indi <divya.indi@oracle.com>
[ Moved to samples/ftrace ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-22 19:41:08 -05:00
Colin Ian King
760f8bc7c8 ftrace/selftests: Fix spelling mistake "wakeing" -> "waking"
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.com

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-15 11:30:38 -05:00
Steven Rostedt (VMware)
ae0cc3b7e7 ftrace/samples: Add a sample module that implements modify_ftrace_direct()
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) <rostedt@goodmis.org>
2019-11-14 22:45:47 -05:00
Steven Rostedt (VMware)
156473a0ff ftrace: Add another example of register_ftrace_direct() use case
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) <rostedt@goodmis.org>
2019-11-13 09:36:49 -05:00
Steven Rostedt (VMware)
b06457c83a ftrace: Add sample module that uses register_ftrace_direct()
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) <rostedt@goodmis.org>
2019-11-13 09:36:49 -05:00