Commit Graph

872764 Commits

Author SHA1 Message Date
128161f47b ftrace: Add helper find_direct_entry() to consolidate code
Both unregister_ftrace_direct() and modify_ftrace_direct() needs to
normalize the ip passed in to match the rec->ip, as it is acceptable to have
the ip on the ftrace call site but not the start. There are also common
validity checks with the record found by the ip, these should be done for
both unregister_ftrace_direct() and modify_ftrace_direct().

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-15 14:25:08 -05:00
406acdd32d ftrace: Add another check for match in register_ftrace_direct()
As an instruction pointer passed into register_ftrace_direct() may just
exist on the ftrace call site, but may not be the start of the call site
itself, register_ftrace_direct() still needs to update test if a direct call
exists on the normalized site, as only one direct call is allowed at any one
time.

Fixes: 763e34e74b ("ftrace: Add register_ftrace_direct()")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-15 14:24:46 -05:00
1c7f9b673d ftrace: Fix accounting bug with direct->count in register_ftrace_direct()
The direct->count wasn't being updated properly, where it only was updated
when the first entry was added, but should be updated every time.

Fixes: 013bf0da04 ("ftrace: Add ftrace_find_direct_func()")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-15 14:23:55 -05:00
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
58a74a2925 tracing: Increase SYNTH_FIELDS_MAX for synthetic_events
Increase the maximum allowed count of synthetic event fields from 16 to 32
in order to allow for larger-than-usual events.

Link: http://lkml.kernel.org/r/20191115091730.9192-1-dedekind1@gmail.com

Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-15 11:30:29 -05:00
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
0567d68091 ftrace: Add modify_ftrace_direct()
Add a new function modify_ftrace_direct() that will allow a user to update
an existing direct caller to a new trampoline, without missing hits due to
unregistering one and then adding another.

Link: https://lore.kernel.org/r/20191109022907.6zzo6orhxpt5n2sv@ast-mbp.dhcp.thefacebook.com

Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-14 22:45:47 -05:00
36b3615dc3 tracing: Add missing "inline" in stub function of latency_fsnotify()
The latency_fsnotify() stub when the function is not defined, was missing
the "inline".

Link: https://lore.kernel.org/r/20191115140213.74c5efe7@canb.auug.org.au

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-14 22:45:47 -05:00
9b4712044d tracing: Remove stray tab in TRACE_EVAL_MAP_FILE's help text
There was a stray tab in the help text of the aforementioned config
option which showed like this:

  The "print fmt" of the trace events will show the enum/sizeof names
  instead        of their values. This can cause problems for user space tools
  ...

in menuconfig. Remove it and end a sentence with a fullstop.

No functional changes.

Link: http://lkml.kernel.org/r/20191112174219.10933-1-bp@alien8.de

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-14 13:15:12 -05:00
ef56e047b2 tracing: Use seq_buf_hex_dump() to dump buffers
Without this, buffers can be printed with __print_array macro that has
no formatting options and can be hard to read. The other way is to
mimic formatting capability with multiple calls of trace event with one
call per row which gives performance impact and different timestamp in
each row.

Link: http://lkml.kernel.org/r/1573130738-29390-2-git-send-email-piotrx.maziarz@linux.intel.com

Signed-off-by: Piotr Maziarz <piotrx.maziarz@linux.intel.com>
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-14 13:15:12 -05:00
353cade314 seq_buf: Add printing formatted hex dumps
Provided function is an analogue of print_hex_dump().

Implementing this function in seq_buf allows using for multiple
purposes (e.g. for tracing) and therefore prevents from code duplication
in every layer that uses seq_buf.

print_hex_dump() is an essential part of logging data to dmesg. Adding
similar capability for other purposes is beneficial to all users.

Example usage:
seq_buf_hex_dump(seq, "", DUMP_PREFIX_OFFSET, 16, 4, buf,
		 ARRAY_SIZE(buf), true);
Example output:
00000000: 00000000 ffffff10 ffffff32 ffff3210  ........2....2..
00000010: ffff3210 83d00437 c0700000 00000000  .2..7.....p.....
00000020: 02010004 0000000f 0000000f 00004002  .............@..
00000030: 00000fff 00000000                    ........

Link: http://lkml.kernel.org/r/1573130738-29390-1-git-send-email-piotrx.maziarz@linux.intel.com

Signed-off-by: Piotr Maziarz <piotrx.maziarz@linux.intel.com>
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-14 13:15:12 -05:00
c7411a1a12 tracing/kprobe: Check whether the non-suffixed symbol is notrace
Check whether the non-suffixed symbol is notrace, since suffixed
symbols are generated by the compilers for optimization. Based on
these suffixed symbols, notrace check might not work because
some of them are just a partial code of the original function.
(e.g. cold-cache (unlikely) code is separated from original
 function as FUNCTION.cold.XX)

For example, without this fix,
  # echo p device_add.cold.67 > /sys/kernel/debug/tracing/kprobe_events
  sh: write error: Invalid argument

  # cat /sys/kernel/debug/tracing/error_log
  [  135.491035] trace_kprobe: error: Failed to register probe event
    Command: p device_add.cold.67
               ^
  # dmesg | tail -n 1
  [  135.488599] trace_kprobe: Could not probe notrace function device_add.cold.67

With this,
  # echo p device_add.cold.66 > /sys/kernel/debug/tracing/kprobe_events
  # cat /sys/kernel/debug/kprobes/list
  ffffffff81599de9  k  device_add.cold.66+0x0    [DISABLED]

Actually, kprobe blacklist already did similar thing,
see within_kprobe_blacklist().

Link: http://lkml.kernel.org/r/157233790394.6706.18243942030937189679.stgit@devnote2

Fixes: 45408c4f92 ("tracing: kprobes: Prohibit probing on notrace function")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-14 13:15:12 -05:00
6ee40511cb tracing: use kvcalloc for tgid_map array allocation
Fail to allocate memory for tgid_map, because it requires order-6 page.
detail as:

c3 sh: page allocation failure: order:6,
   mode:0x140c0c0(GFP_KERNEL), nodemask=(null)
c3 sh cpuset=/ mems_allowed=0
c3 CPU: 3 PID: 5632 Comm: sh Tainted: G        W  O    4.14.133+ #10
c3 Hardware name: Generic DT based system
c3 Backtrace:
c3 [<c010bdbc>] (dump_backtrace) from [<c010c08c>](show_stack+0x18/0x1c)
c3 [<c010c074>] (show_stack) from [<c0993c54>](dump_stack+0x84/0xa4)
c3 [<c0993bd0>] (dump_stack) from [<c0229858>](warn_alloc+0xc4/0x19c)
c3 [<c0229798>] (warn_alloc) from [<c022a6e4>](__alloc_pages_nodemask+0xd18/0xf28)
c3 [<c02299cc>] (__alloc_pages_nodemask) from [<c0248344>](kmalloc_order+0x20/0x38)
c3 [<c0248324>] (kmalloc_order) from [<c0248380>](kmalloc_order_trace+0x24/0x108)
c3 [<c024835c>] (kmalloc_order_trace) from [<c01e6078>](set_tracer_flag+0xb0/0x158)
c3 [<c01e5fc8>] (set_tracer_flag) from [<c01e6404>](trace_options_core_write+0x7c/0xcc)
c3 [<c01e6388>] (trace_options_core_write) from [<c0278b1c>](__vfs_write+0x40/0x14c)
c3 [<c0278adc>] (__vfs_write) from [<c0278e10>](vfs_write+0xc4/0x198)
c3 [<c0278d4c>] (vfs_write) from [<c027906c>](SyS_write+0x6c/0xd0)
c3 [<c0279000>] (SyS_write) from [<c01079a0>](ret_fast_syscall+0x0/0x54)

Switch to use kvcalloc to avoid unexpected allocation failures.

Link: http://lkml.kernel.org/r/1571888070-24425-1-git-send-email-chunyan.zhang@unisoc.com

Signed-off-by: Yuming Han <yuming.han@unisoc.com>
Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-14 13:15:11 -05:00
0c3c86bdc6 tracing/hwlat: Fix a few trivial nits
Update the source file name in the comments, and fix a grammatical
error.

Link: http://lkml.kernel.org/r/157073346821.17189.8946944856026592247.stgit@srivatsa-ubuntu

Signed-off-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-14 13:15:11 -05:00
80042c8f06 tracing: Use generic type for comparator function
Comparator function type, cmp_func_t, is defined in the types.h,
use it in the code.

Link: http://lkml.kernel.org/r/20191007135656.37734-3-andriy.shevchenko@linux.intel.com

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-14 13:15:11 -05:00
e8877ec5db lib/bsearch: Use generic type for comparator function
Comparator function type, cmp_func_t, is defined in the types.h,
use it in bsearch() and, thus, add more sense to the corresponding
comment in the code.

Link: http://lkml.kernel.org/r/20191007135656.37734-2-andriy.shevchenko@linux.intel.com

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-14 13:15:11 -05:00
52ae533b8a lib/sort: Move swap, cmp and cmp_r function types for wider use
The function types for swap, cmp and cmp_r functions are already
being in use by modules.

Move them to types.h that everybody in kernel will be able to use
generic types instead of custom ones.

This adds more sense to the comment in bsearch() later on.

Link: http://lkml.kernel.org/r/20191007135656.37734-1-andriy.shevchenko@linux.intel.com

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-14 13:15:11 -05:00
b43e78f65b tracing/selftests: Turn off timeout setting
As the ftrace selftests can run for a long period of time, disable the
timeout that the general selftests have. If a selftest hangs, then it
probably means the machine will hang too.

Link: https://lore.kernel.org/r/alpine.LSU.2.21.1911131604170.18679@pobox.suse.cz

Suggested-by: Miroslav Benes <mbenes@suse.cz>
Tested-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-14 13:15:11 -05:00
b83b43ffc6 fgraph: Fix function type mismatches of ftrace_graph_return using ftrace_stub
The C compiler is allowing more checks to make sure that function pointers
are assigned to the correct prototype function. Unfortunately, the function
graph tracer uses a special name with its assigned ftrace_graph_return
function pointer that maps to a stub function used by the function tracer
(ftrace_stub). The ftrace_graph_return variable is compared to the
ftrace_stub in some archs to know if the function graph tracer is enabled or
not. This means we can not just simply create a new function stub that
compares it without modifying all the archs.

Instead, have the linker script create a function_graph_stub that maps to
ftrace_stub, and this way we can define the prototype for it to match the
prototype of ftrace_graph_return, and make the compiler checks all happy!

Link: http://lkml.kernel.org/r/20191015090055.789a0aed@gandalf.local.home

Cc: linux-sh@vger.kernel.org
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc:  Rich Felker <dalias@libc.org>
Reported-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-14 13:13:43 -05:00
953ae45a0c tracing: Adding NULL checks for trace_array descriptor pointer
As part of commit f45d1225ad ("tracing: Kernel access to Ftrace
instances") we exported certain functions. Here, we are adding some additional
NULL checks to ensure safe usage by users of these APIs.

Link: http://lkml.kernel.org/r/1565805327-579-4-git-send-email-divya.indi@oracle.com

Signed-off-by: Divya Indi <divya.indi@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-13 09:37:29 -05:00
e585e6469d tracing: Verify if trace array exists before destroying it.
A trace array can be destroyed from userspace or kernel. Verify if the
trace array exists before proceeding to destroy/remove it.

Link: http://lkml.kernel.org/r/1565805327-579-3-git-send-email-divya.indi@oracle.com

Reviewed-by: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
Signed-off-by: Divya Indi <divya.indi@oracle.com>
[ Removed unneeded braces ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-13 09:37:29 -05:00
2d6425af61 tracing: Declare newly exported APIs in include/linux/trace.h
Declare the newly introduced and exported APIs in the header file -
include/linux/trace.h. Moving previous declarations from
kernel/trace/trace.h to include/linux/trace.h.

Link: http://lkml.kernel.org/r/1565805327-579-2-git-send-email-divya.indi@oracle.com

Signed-off-by: Divya Indi <divya.indi@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-13 09:37:29 -05:00
6dff4d7dd3 tracing: Make internal ftrace events static
The event_class_ftrace_##call and event_##call do not seem
to be used outside of trace_export.c so make them both static
to avoid a number of sparse warnings:

kernel/trace/trace_entries.h:59:1: warning: symbol 'event_class_ftrace_function' was not declared. Should it be static?
kernel/trace/trace_entries.h:59:1: warning: symbol '__event_function' was not declared. Should it be static?
kernel/trace/trace_entries.h:77:1: warning: symbol 'event_class_ftrace_funcgraph_entry' was not declared. Should it be static?
kernel/trace/trace_entries.h:77:1: warning: symbol '__event_funcgraph_entry' was not declared. Should it be static?
kernel/trace/trace_entries.h:93:1: warning: symbol 'event_class_ftrace_funcgraph_exit' was not declared. Should it be static?
kernel/trace/trace_entries.h:93:1: warning: symbol '__event_funcgraph_exit' was not declared. Should it be static?
kernel/trace/trace_entries.h:129:1: warning: symbol 'event_class_ftrace_context_switch' was not declared. Should it be static?
kernel/trace/trace_entries.h:129:1: warning: symbol '__event_context_switch' was not declared. Should it be static?
kernel/trace/trace_entries.h:149:1: warning: symbol 'event_class_ftrace_wakeup' was not declared. Should it be static?
kernel/trace/trace_entries.h:149:1: warning: symbol '__event_wakeup' was not declared. Should it be static?
kernel/trace/trace_entries.h:171:1: warning: symbol 'event_class_ftrace_kernel_stack' was not declared. Should it be static?
kernel/trace/trace_entries.h:171:1: warning: symbol '__event_kernel_stack' was not declared. Should it be static?
kernel/trace/trace_entries.h:191:1: warning: symbol 'event_class_ftrace_user_stack' was not declared. Should it be static?
kernel/trace/trace_entries.h:191:1: warning: symbol '__event_user_stack' was not declared. Should it be static?
kernel/trace/trace_entries.h:214:1: warning: symbol 'event_class_ftrace_bprint' was not declared. Should it be static?
kernel/trace/trace_entries.h:214:1: warning: symbol '__event_bprint' was not declared. Should it be static?
kernel/trace/trace_entries.h:230:1: warning: symbol 'event_class_ftrace_print' was not declared. Should it be static?
kernel/trace/trace_entries.h:230:1: warning: symbol '__event_print' was not declared. Should it be static?
kernel/trace/trace_entries.h:247:1: warning: symbol 'event_class_ftrace_raw_data' was not declared. Should it be static?
kernel/trace/trace_entries.h:247:1: warning: symbol '__event_raw_data' was not declared. Should it be static?
kernel/trace/trace_entries.h:262:1: warning: symbol 'event_class_ftrace_bputs' was not declared. Should it be static?
kernel/trace/trace_entries.h:262:1: warning: symbol '__event_bputs' was not declared. Should it be static?
kernel/trace/trace_entries.h:277:1: warning: symbol 'event_class_ftrace_mmiotrace_rw' was not declared. Should it be static?
kernel/trace/trace_entries.h:277:1: warning: symbol '__event_mmiotrace_rw' was not declared. Should it be static?
kernel/trace/trace_entries.h:298:1: warning: symbol 'event_class_ftrace_mmiotrace_map' was not declared. Should it be static?
kernel/trace/trace_entries.h:298:1: warning: symbol '__event_mmiotrace_map' was not declared. Should it be static?
kernel/trace/trace_entries.h:322:1: warning: symbol 'event_class_ftrace_branch' was not declared. Should it be static?
kernel/trace/trace_entries.h:322:1: warning: symbol '__event_branch' was not declared. Should it be static?
kernel/trace/trace_entries.h:343:1: warning: symbol 'event_class_ftrace_hwlat' was not declared. Should it be static?
kernel/trace/trace_entries.h:343:1: warning: symbol '__event_hwlat' was not declared. Should it be static?

Link: http://lkml.kernel.org/r/20191015121012.18824-1-ben.dooks@codethink.co.uk

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-13 09:37:29 -05:00
9c34fc4b7e tracing: Use CONFIG_PREEMPTION
CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by CONFIG_PREEMPT_RT.
Both PREEMPT and PREEMPT_RT require the same functionality which today
depends on CONFIG_PREEMPT.

Add additional header output for PREEMPT_RT.
Link: http://lkml.kernel.org/r/20191015191821.11479-34-bigeasy@linutronix.de

Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-13 09:37:28 -05:00
793937236d preemptirq_delay_test: Add the burst feature and a sysfs trigger
This burst feature enables the user to generate a burst of
preempt/irqsoff latencies. This makes it possible to test whether we
are able to detect latencies that systematically occur very close to
each other.

The maximum burst size is 10. We also create 10 identical test
functions, so that we get 10 different backtraces; this is useful
when we want to test whether we can detect all the latencies in a
burst. Otherwise, there would be no easy way of differentiating
between which latency in a burst was captured by the tracer.

In addition, there is a sysfs trigger, so that it's not necessary to
reload the module to repeat the test. The trigger will appear as
/sys/kernel/preemptirq_delay_test/trigger in sysfs.

Link: http://lkml.kernel.org/r/20191008220824.7911-3-viktor.rosendahl@gmail.com

Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Viktor Rosendahl (BMW) <viktor.rosendahl@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-13 09:37:28 -05:00
91edde2e6a ftrace: Implement fs notification for tracing_max_latency
This patch implements the feature that the tracing_max_latency file,
e.g. /sys/kernel/debug/tracing/tracing_max_latency will receive
notifications through the fsnotify framework when a new latency is
available.

One particularly interesting use of this facility is when enabling
threshold tracing, through /sys/kernel/debug/tracing/tracing_thresh,
together with the preempt/irqsoff tracers. This makes it possible to
implement a user space program that can, with equal probability,
obtain traces of latencies that occur immediately after each other in
spite of the fact that the preempt/irqsoff tracers operate in overwrite
mode.

This facility works with the hwlat, preempt/irqsoff, and wakeup
tracers.

The tracers may call the latency_fsnotify() from places such as
__schedule() or do_idle(); this makes it impossible to call
queue_work() directly without risking a deadlock. The same would
happen with a softirq,  kernel thread or tasklet. For this reason we
use the irq_work mechanism to call queue_work().

This patch creates a new workqueue. The reason for doing this is that
I wanted to use the WQ_UNBOUND and WQ_HIGHPRI flags.  My thinking was
that WQ_UNBOUND might help with the latency in some important cases.

If we use:

queue_work(system_highpri_wq, &tr->fsnotify_work);

then the work will (almost) always execute on the same CPU but if we are
unlucky that CPU could be too busy while there could be another CPU in
the system that would be able to process the work soon enough.

queue_work_on() could be used to queue the work on another CPU but it
seems difficult to select the right CPU.

Link: http://lkml.kernel.org/r/20191008220824.7911-2-viktor.rosendahl@gmail.com

Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Viktor Rosendahl (BMW) <viktor.rosendahl@gmail.com>
[ Added max() to have one compare for max latency ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-13 09:37:28 -05:00
da537f0aef ftrace: Add information on number of page groups allocated
Looking for ways to shrink the size of the dyn_ftrace structure, knowing the
information about how many pages and the number of groups of those pages, is
useful in working out the best ways to save on memory.

This adds one info print on how many groups of pages were used to allocate
the ftrace dyn_ftrace structures, and also shows the number of pages and
groups in the dyn_ftrace_total_info (which is used for debugging).

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-13 09:37:28 -05:00
77ac117b3a ftrace/x86: Tell objtool to ignore nondeterministic ftrace stack layout
Objtool complains about the new ftrace direct trampoline code:

  arch/x86/kernel/ftrace_64.o: warning: objtool: ftrace_regs_caller()+0x190: stack state mismatch: cfa1=7+16 cfa2=7+24

Typically, code has a deterministic stack layout, such that at a given
instruction address, the stack frame size is always the same.

That's not the case for the new ftrace_regs_caller() code after it
adjusts the stack for the direct case.  Just plead ignorance and assume
it's always the non-direct path.  Note this creates a tiny window for
ORC to get confused.

Link: http://lkml.kernel.org/r/20191108225100.ea3bhsbdf6oerj6g@treble

Reported-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-13 09:36:50 -05:00
a3ad1a7e39 ftrace/x86: Add a counter to test function_graph with direct
As testing for direct calls from the function graph tracer adds a little
overhead (which is a lot when tracing every function), add a counter that
can be used to test if function_graph tracer needs to test for a direct
caller or not.

It would have been nicer if we could use a static branch, but the static
branch logic fails when used within the function graph tracer trampoline.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-13 09:36:49 -05:00
562955fe6a ftrace/x86: Add register_ftrace_direct() for custom trampolines
Enable x86 to allow for register_ftrace_direct(), where a custom trampoline
may be called directly from an ftrace mcount/fentry location.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-13 09:36:49 -05:00
ed9dafebce ftrace/selftests: Update the direct call selftests to test two direct calls
The register_ftrace_direct() takes a different path if there's already a
direct call registered, but this was not tested in the self tests. Now that
there's a second direct caller test module, we can use this to test not only
one direct caller, but two.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-13 09:36:49 -05:00
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
646f01ccdd ftrace/selftest: Add tests to test register_ftrace_direct()
Add two test cases that test the new ftrace direct functionality if the
ftrace-direct sample module is available. One test case tests against each
available tracer (function, function_graph, mmiotrace, etc), and the other
test tests against a kprobe at the same location as the direct caller. Both
tests follow the same pattern of testing combinations:

  enable test (either the tracer or the kprobe)
  load direct function module
  unload direct function module
  disable test

  enable test
  load direct function module
  disable test
  unload direct function module

  load direct function module
  enable test
  disable test
  unload direct function module

  load direct function module
  enable test
  unload direct function module
  disable test

As most the bugs in development happened with various ways of enabling or
disabling the direct calls with function tracer in one of these
combinations.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-13 09:36:49 -05:00
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
013bf0da04 ftrace: Add ftrace_find_direct_func()
As function_graph tracer modifies the return address to insert a trampoline
to trace the return of a function, it must be aware of a direct caller, as
when it gets called, the function's return address may not be at on the
stack where it expects. It may have to see if that return address points to
the a direct caller and adjust if it is.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-13 09:36:48 -05:00
763e34e74b ftrace: Add register_ftrace_direct()
Add the start of the functionality to allow other trampolines to use the
ftrace mcount/fentry/nop location. This adds two new functions:

 register_ftrace_direct() and unregister_ftrace_direct()

Both take two parameters: the first is the instruction address of where the
mcount/fentry/nop exists, and the second is the trampoline to have that
location called.

This will handle cases where ftrace is already used on that same location,
and will make it still work, where the registered direct called trampoline
will get called after all the registered ftrace callers are handled.

Currently, it will not allow for IP_MODIFY functions to be called at the
same locations, which include some kprobes and live kernel patching.

At this point, no architecture supports this. This is only the start of
implementing the framework.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-13 09:36:41 -05:00
7e16f581a8 ftrace: Separate out functionality from ftrace_location_range()
Create a new function called lookup_rec() from the functionality of
ftrace_location_range(). The difference between lookup_rec() is that it
returns the record that it finds, where as ftrace_location_range() returns
only if it found a match or not.

The lookup_rec() is static, and can be used for new functionality where
ftrace needs to find a record of a specific address.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-08 12:26:46 -05:00
714641c367 ftrace: Separate out the copying of a ftrace_hash from __ftrace_hash_move()
Most of the functionality of __ftrace_hash_move() can be reused, but not all
of it. That is, __ftrace_hash_move() is used to simply make a new hash from
an existing one, using the same size as the original. Creating a dup_hash(),
where we can specify a new size will be useful when we want to create a hash
with a default size, or simply copy the old one.

Signed-off-by: Steven Rostedt (VMWare) <rostedt@goodmis.org>
2019-11-08 12:25:46 -05:00
8c666d2ab5 selftests/livepatch: Test interaction with ftrace_enabled
Since livepatching depends upon ftrace handlers to implement "patched"
code functionality, verify that the ftrace_enabled sysctl value
interacts with livepatch registration as expected.  At the same time,
ensure that ftrace_enabled is set and part of the test environment
configuration that is saved and restored when running the selftests.

Link: http://lkml.kernel.org/r/20191016113316.13415-4-mbenes@suse.cz

Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-04 09:33:16 -05:00
35c9e74cff selftests/livepatch: Make dynamic debug setup and restore generic
Livepatch selftests currently save the current dynamic debug config and
tweak it for the selftests. The config is restored at the end. Make the
infrastructure generic, so that more variables can be saved and
restored.

Link: http://lkml.kernel.org/r/20191016113316.13415-3-mbenes@suse.cz

Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-04 09:33:15 -05:00
7162431dcf ftrace: Introduce PERMANENT ftrace_ops flag
Livepatch uses ftrace for redirection to new patched functions. It means
that if ftrace is disabled, all live patched functions are disabled as
well. Toggling global 'ftrace_enabled' sysctl thus affect it directly.
It is not a problem per se, because only administrator can set sysctl
values, but it still may be surprising.

Introduce PERMANENT ftrace_ops flag to amend this. If the
FTRACE_OPS_FL_PERMANENT is set on any ftrace ops, the tracing cannot be
disabled by disabling ftrace_enabled. Equally, a callback with the flag
set cannot be registered if ftrace_enabled is disabled.

Link: http://lkml.kernel.org/r/20191016113316.13415-2-mbenes@suse.cz

Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-04 09:33:15 -05:00
a99d8080aa Linux 5.4-rc6 2019-11-03 14:07:26 -08:00
3a69c9e522 Merge tag 'usb-5.4-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Pull USB fixes from Greg KH:
 "The USB sub-maintainers woke up this past week and sent a bunch of
  tiny fixes. Here are a lot of small patches that that resolve a bunch
  of reported issues in the USB core, drivers, serial drivers, gadget
  drivers, and of course, xhci :)

  All of these have been in linux-next with no reported issues"

* tag 'usb-5.4-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (31 commits)
  usb: dwc3: gadget: fix race when disabling ep with cancelled xfers
  usb: cdns3: gadget: Fix g_audio use case when connected to Super-Speed host
  usb: cdns3: gadget: reset EP_CLAIMED flag while unloading
  USB: serial: whiteheat: fix line-speed endianness
  USB: serial: whiteheat: fix potential slab corruption
  USB: gadget: Reject endpoints with 0 maxpacket value
  UAS: Revert commit 3ae62a4209 ("UAS: fix alignment of scatter/gather segments")
  usb-storage: Revert commit 747668dbc0 ("usb-storage: Set virt_boundary_mask to avoid SG overflows")
  usbip: Fix free of unallocated memory in vhci tx
  usbip: tools: Fix read_usb_vudc_device() error path handling
  usb: xhci: fix __le32/__le64 accessors in debugfs code
  usb: xhci: fix Immediate Data Transfer endianness
  xhci: Fix use-after-free regression in xhci clear hub TT implementation
  USB: ldusb: fix control-message timeout
  USB: ldusb: use unsigned size format specifiers
  USB: ldusb: fix ring-buffer locking
  USB: Skip endpoints with 0 maxpacket length
  usb: cdns3: gadget: Don't manage pullups
  usb: dwc3: remove the call trace of USBx_GFLADJ
  usb: gadget: configfs: fix concurrent issue between composite APIs
  ...
2019-11-03 08:25:25 -08:00
56cfd2507d Merge tag '5.4-rc6-smb3-fix' of git://git.samba.org/sfrench/cifs-2.6
Pull cifs fix from Steve French:
 "A small smb3 memleak fix"

* tag '5.4-rc6-smb3-fix' of git://git.samba.org/sfrench/cifs-2.6:
  fix memory leak in large read decrypt offload
2019-11-02 14:34:00 -07:00
9d23450575 Merge tag 'hwmon-for-v5.4-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging
Pull hwmon fixes from Guenter Roeck:

 - Fix read timeout problem in ina3221 driver

 - Fix wrong bitmask in nct7904 driver

* tag 'hwmon-for-v5.4-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (ina3221) Fix read timeout issue
  hwmon: (nct7904) Fix the incorrect value of vsen_mask & tcpu_mask & temp_mode in nct7904_data struct.
2019-11-02 11:28:59 -07:00
e935842a06 Merge tag 'pwm/for-5.4-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm
Pull pwm fixes from Thierry Reding:
 "It turned out that relying solely on drivers storing all the PWM state
  in hardware was a little premature and causes a number of subtle (and
  some not so subtle) regressions. Revert the offending patch for now"

* tag 'pwm/for-5.4-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm:
  Revert "pwm: Let pwm_get_state() return the last implemented state"
2019-11-02 11:23:09 -07:00
f83e148a41 Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI fixes from James Bottomley:
 "Nine changes, eight in drivers [ufs, target, lpfc x 2, qla2xxx x 4]
  and one core change in sd that fixes an I/O failure on DIF type 3
  devices"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: qla2xxx: stop timer in shutdown path
  scsi: sd: define variable dif as unsigned int instead of bool
  scsi: target: cxgbit: Fix cxgbit_fw4_ack()
  scsi: qla2xxx: Fix partial flash write of MBI
  scsi: qla2xxx: Initialized mailbox to prevent driver load failure
  scsi: lpfc: Honor module parameter lpfc_use_adisc
  scsi: ufs-bsg: Wake the device before sending raw upiu commands
  scsi: lpfc: Check queue pointer before use
  scsi: qla2xxx: fixup incorrect usage of host_byte
2019-11-02 11:15:52 -07:00
8194c28efd Merge tag 'powerpc-5.4-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
 "Our recent cleanup of EEH led to an oops on bare metal machines when
  the cxl (CAPI) driver creates virtual devices for an attached FPGA
  accelerator.

  The "secure virtual machine" support we added in v5.4 had a bug if the
  kernel was relocated (moved during boot), in those cases the signature
  of the kernel text wouldn't verify and the Ultravisor would refuse to
  run the VM.

  A recent change to disable interrupts before calling
  arch_cpu_idle_dead() caused a WARN_ON() in our bare metal CPU offline
  code to always trigger.

  The KUAP (SMAP) support we added for 32-bit Book3S had a bug if the
  address range crossed a segment (256MB) boundary which could lead to
  spurious faults.

  Thanks to: Christophe Leroy, Frederic Barrat, Michael Anderson,
  Nicholas Piggin, Sam Bobroff, Thiago Jung Bauermann"

* tag 'powerpc-5.4-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/powernv: Fix CPU idle to be called with IRQs disabled
  powerpc/prom_init: Undo relocation before entering secure mode
  powerpc/powernv/eeh: Fix oops when probing cxl devices
  powerpc/32s: fix allow/prevent_user_access() when crossing segment boundaries.
2019-11-02 11:08:19 -07:00
969a5197da Merge tag 's390-5.4-6' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 fixes from Vasily Gorbik:

 - Fix cpu idle time accounting

 - Fix stack unwinder case when both pt_regs and sp are specified

 - Fix information leak via cmm timeout proc handler

* tag 's390-5.4-6' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/idle: fix cpu idle time calculation
  s390/unwind: fix mixing regs and sp
  s390/cmm: fix information leak in cmm_timeout_handler()
2019-11-02 11:00:26 -07:00
1204c70d9d Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from David Miller:

 1) Fix free/alloc races in batmanadv, from Sven Eckelmann.

 2) Several leaks and other fixes in kTLS support of mlx5 driver, from
    Tariq Toukan.

 3) BPF devmap_hash cost calculation can overflow on 32-bit, from Toke
    Høiland-Jørgensen.

 4) Add an r8152 device ID, from Kazutoshi Noguchi.

 5) Missing include in ipv6's addrconf.c, from Ben Dooks.

 6) Use siphash in flow dissector, from Eric Dumazet. Attackers can
    easily infer the 32-bit secret otherwise etc.

 7) Several netdevice nesting depth fixes from Taehee Yoo.

 8) Fix several KCSAN reported errors, from Eric Dumazet. For example,
    when doing lockless skb_queue_empty() checks, and accessing
    sk_napi_id/sk_incoming_cpu lockless as well.

 9) Fix jumbo packet handling in RXRPC, from David Howells.

10) Bump SOMAXCONN and tcp_max_syn_backlog values, from Eric Dumazet.

11) Fix DMA synchronization in gve driver, from Yangchun Fu.

12) Several bpf offload fixes, from Jakub Kicinski.

13) Fix sk_page_frag() recursion during memory reclaim, from Tejun Heo.

14) Fix ping latency during high traffic rates in hisilicon driver, from
    Jiangfent Xiao.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (146 commits)
  net: fix installing orphaned programs
  net: cls_bpf: fix NULL deref on offload filter removal
  selftests: bpf: Skip write only files in debugfs
  selftests: net: reuseport_dualstack: fix uninitalized parameter
  r8169: fix wrong PHY ID issue with RTL8168dp
  net: dsa: bcm_sf2: Fix IMP setup for port different than 8
  net: phylink: Fix phylink_dbg() macro
  gve: Fixes DMA synchronization.
  inet: stop leaking jiffies on the wire
  ixgbe: Remove duplicate clear_bit() call
  Documentation: networking: device drivers: Remove stray asterisks
  e1000: fix memory leaks
  i40e: Fix receive buffer starvation for AF_XDP
  igb: Fix constant media auto sense switching when no cable is connected
  net: ethernet: arc: add the missed clk_disable_unprepare
  igb: Enable media autosense for the i350.
  igb/igc: Don't warn on fatal read failures when the device is removed
  tcp: increase tcp_max_syn_backlog max value
  net: increase SOMAXCONN to 4096
  netdevsim: Fix use-after-free during device dismantle
  ...
2019-11-01 17:48:11 -07:00