Commit Graph

5157 Commits

Author SHA1 Message Date
Linus Torvalds
f40a33f5ea Merge tag 'trace-v5.17-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:

 - Fix sorting on old "cpu" value in histograms

 - Fix return value of __setup() boot parameter handlers

* tag 'trace-v5.17-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix return value of __setup handlers
  tracing/histogram: Fix sorting on old "cpu" value
2022-03-06 11:47:59 -08:00
Linus Torvalds
ac84e82f78 Merge tag 'block-5.17-2022-03-04' of git://git.kernel.dk/linux-block
Pull block fix from Jens Axboe:
 "Just a small UAF fix for blktrace"

* tag 'block-5.17-2022-03-04' of git://git.kernel.dk/linux-block:
  blktrace: fix use after free for struct blk_trace
2022-03-04 16:03:46 -08:00
Randy Dunlap
1d02b444b8 tracing: Fix return value of __setup handlers
__setup() handlers should generally return 1 to indicate that the
boot options have been handled.

Using invalid option values causes the entire kernel boot option
string to be reported as Unknown and added to init's environment
strings, polluting it.

  Unknown kernel command line parameters "BOOT_IMAGE=/boot/bzImage-517rc6
    kprobe_event=p,syscall_any,$arg1 trace_options=quiet
    trace_clock=jiffies", will be passed to user space.

 Run /sbin/init as init process
   with arguments:
     /sbin/init
   with environment:
     HOME=/
     TERM=linux
     BOOT_IMAGE=/boot/bzImage-517rc6
     kprobe_event=p,syscall_any,$arg1
     trace_options=quiet
     trace_clock=jiffies

Return 1 from the __setup() handlers so that init's environment is not
polluted with kernel boot options.

Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Link: https://lkml.kernel.org/r/20220303031744.32356-1-rdunlap@infradead.org

Cc: stable@vger.kernel.org
Fixes: 7bcfaf54f5 ("tracing: Add trace_options kernel command line parameter")
Fixes: e1e232ca6b ("tracing: Add trace_clock=<clock> kernel parameter")
Fixes: 970988e19e ("tracing/kprobe: Add kprobe_event= boot parameter")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-04 13:46:13 -05:00
Steven Rostedt (Google)
1d1898f656 tracing/histogram: Fix sorting on old "cpu" value
When trying to add a histogram against an event with the "cpu" field, it
was impossible due to "cpu" being a keyword to key off of the running CPU.
So to fix this, it was changed to "common_cpu" to match the other generic
fields (like "common_pid"). But since some scripts used "cpu" for keying
off of the CPU (for events that did not have "cpu" as a field, which is
most of them), a backward compatibility trick was added such that if "cpu"
was used as a key, and the event did not have "cpu" as a field name, then
it would fallback and switch over to "common_cpu".

This fix has a couple of subtle bugs. One was that when switching over to
"common_cpu", it did not change the field name, it just set a flag. But
the code still found a "cpu" field. The "cpu" field is used for filtering
and is returned when the event does not have a "cpu" field.

This was found by:

  # cd /sys/kernel/tracing
  # echo hist:key=cpu,pid:sort=cpu > events/sched/sched_wakeup/trigger
  # cat events/sched/sched_wakeup/hist

Which showed the histogram unsorted:

{ cpu:         19, pid:       1175 } hitcount:          1
{ cpu:          6, pid:        239 } hitcount:          2
{ cpu:         23, pid:       1186 } hitcount:         14
{ cpu:         12, pid:        249 } hitcount:          2
{ cpu:          3, pid:        994 } hitcount:          5

Instead of hard coding the "cpu" checks, take advantage of the fact that
trace_event_field_field() returns a special field for "cpu" and "CPU" if
the event does not have "cpu" as a field. This special field has the
"filter_type" of "FILTER_CPU". Check that to test if the returned field is
of the CPU type instead of doing the string compare.

Also, fix the sorting bug by testing for the hist_field flag of
HIST_FIELD_FL_CPU when setting up the sort routine. Otherwise it will use
the special CPU field to know what compare routine to use, and since that
special field does not have a size, it returns tracing_map_cmp_none.

Cc: stable@vger.kernel.org
Fixes: 1e3bac71c5 ("tracing/histogram: Rename "cpu" to "common_cpu"")
Reported-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-01 22:48:30 -05:00
Yu Kuai
3093929326 blktrace: fix use after free for struct blk_trace
When tracing the whole disk, 'dropped' and 'msg' will be created
under 'q->debugfs_dir' and 'bt->dir' is NULL, thus blk_trace_free()
won't remove those files. What's worse, the following UAF can be
triggered because of accessing stale 'dropped' and 'msg':

==================================================================
BUG: KASAN: use-after-free in blk_dropped_read+0x89/0x100
Read of size 4 at addr ffff88816912f3d8 by task blktrace/1188

CPU: 27 PID: 1188 Comm: blktrace Not tainted 5.17.0-rc4-next-20220217+ #469
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-4
Call Trace:
 <TASK>
 dump_stack_lvl+0x34/0x44
 print_address_description.constprop.0.cold+0xab/0x381
 ? blk_dropped_read+0x89/0x100
 ? blk_dropped_read+0x89/0x100
 kasan_report.cold+0x83/0xdf
 ? blk_dropped_read+0x89/0x100
 kasan_check_range+0x140/0x1b0
 blk_dropped_read+0x89/0x100
 ? blk_create_buf_file_callback+0x20/0x20
 ? kmem_cache_free+0xa1/0x500
 ? do_sys_openat2+0x258/0x460
 full_proxy_read+0x8f/0xc0
 vfs_read+0xc6/0x260
 ksys_read+0xb9/0x150
 ? vfs_write+0x3d0/0x3d0
 ? fpregs_assert_state_consistent+0x55/0x60
 ? exit_to_user_mode_prepare+0x39/0x1e0
 do_syscall_64+0x35/0x80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fbc080d92fd
Code: ce 20 00 00 75 10 b8 00 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 1
RSP: 002b:00007fbb95ff9cb0 EFLAGS: 00000293 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007fbb95ff9dc0 RCX: 00007fbc080d92fd
RDX: 0000000000000100 RSI: 00007fbb95ff9cc0 RDI: 0000000000000045
RBP: 0000000000000045 R08: 0000000000406299 R09: 00000000fffffffd
R10: 000000000153afa0 R11: 0000000000000293 R12: 00007fbb780008c0
R13: 00007fbb78000938 R14: 0000000000608b30 R15: 00007fbb780029c8
 </TASK>

Allocated by task 1050:
 kasan_save_stack+0x1e/0x40
 __kasan_kmalloc+0x81/0xa0
 do_blk_trace_setup+0xcb/0x410
 __blk_trace_setup+0xac/0x130
 blk_trace_ioctl+0xe9/0x1c0
 blkdev_ioctl+0xf1/0x390
 __x64_sys_ioctl+0xa5/0xe0
 do_syscall_64+0x35/0x80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 1050:
 kasan_save_stack+0x1e/0x40
 kasan_set_track+0x21/0x30
 kasan_set_free_info+0x20/0x30
 __kasan_slab_free+0x103/0x180
 kfree+0x9a/0x4c0
 __blk_trace_remove+0x53/0x70
 blk_trace_ioctl+0x199/0x1c0
 blkdev_common_ioctl+0x5e9/0xb30
 blkdev_ioctl+0x1a5/0x390
 __x64_sys_ioctl+0xa5/0xe0
 do_syscall_64+0x35/0x80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff88816912f380
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 88 bytes inside of
 96-byte region [ffff88816912f380, ffff88816912f3e0)
The buggy address belongs to the page:
page:000000009a1b4e7c refcount:1 mapcount:0 mapping:0000000000000000 index:0x0f
flags: 0x17ffffc0000200(slab|node=0|zone=2|lastcpupid=0x1fffff)
raw: 0017ffffc0000200 ffffea00044f1100 dead000000000002 ffff88810004c780
raw: 0000000000000000 0000000000200020 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88816912f280: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff88816912f300: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff88816912f380: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                                                    ^
 ffff88816912f400: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff88816912f480: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
==================================================================

Fixes: c0ea57608b ("blktrace: remove debugfs file dentries from struct blk_trace")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20220228034354.4047385-1-yukuai3@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-02-28 06:36:33 -07:00
Christophe Leroy
c5229a0bd4 tracing: Fix selftest config check for function graph start up test
CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS is required to test
direct tramp.

Link: https://lkml.kernel.org/r/bdc7e594e13b0891c1d61bc8d56c94b1890eaed7.1640017960.git.christophe.leroy@csgroup.eu

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-25 21:05:29 -05:00
Daniel Bristot de Oliveira
dd990352f0 tracing/osnoise: Make osnoise_main to sleep for microseconds
osnoise's runtime and period are in the microseconds scale, but it is
currently sleeping in the millisecond's scale. This behavior roots in the
usage of hwlat as the skeleton for osnoise.

Make osnoise to sleep in the microseconds scale. Also, move the sleep to
a specialized function.

Link: https://lkml.kernel.org/r/302aa6c7bdf2d131719b22901905e9da122a11b2.1645197336.git.bristot@kernel.org

Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-25 12:07:01 -05:00
Nathan Chancellor
ab2f993c01 ftrace: Remove unused ftrace_startup_enable() stub
When building with clang + CONFIG_DYNAMIC_FTRACE=n + W=1, there is a
warning:

  kernel/trace/ftrace.c:7194:20: error: unused function 'ftrace_startup_enable' [-Werror,-Wunused-function]
  static inline void ftrace_startup_enable(int command) { }
                     ^
  1 error generated.

Clang warns on instances of static inline functions in .c files with W=1
after commit 6863f5643d ("kbuild: allow Clang to find unused static
inline functions for W=1 build").

The ftrace_startup_enable() stub has been unused since
commit e1effa0144 ("ftrace: Annotate the ops operation on update"),
where its use outside of the CONFIG_DYNAMIC_TRACE section was replaced
by ftrace_startup_all().  Remove it to resolve the warning.

Link: https://lkml.kernel.org/r/20220214192847.488166-1-nathan@kernel.org

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-25 12:07:01 -05:00
Sven Schnelle
7acf3a127b tracing: Ensure trace buffer is at least 4096 bytes large
Booting the kernel with 'trace_buf_size=1' give a warning at
boot during the ftrace selftests:

[    0.892809] Running postponed tracer tests:
[    0.892893] Testing tracer function:
[    0.901899] Callback from call_rcu_tasks_trace() invoked.
[    0.983829] Callback from call_rcu_tasks_rude() invoked.
[    1.072003] .. bad ring buffer .. corrupted trace buffer ..
[    1.091944] Callback from call_rcu_tasks() invoked.
[    1.097695] PASSED
[    1.097701] Testing dynamic ftrace: .. filter failed count=0 ..FAILED!
[    1.353474] ------------[ cut here ]------------
[    1.353478] WARNING: CPU: 0 PID: 1 at kernel/trace/trace.c:1951 run_tracer_selftest+0x13c/0x1b0

Therefore enforce a minimum of 4096 bytes to make the selftest pass.

Link: https://lkml.kernel.org/r/20220214134456.1751749-1-svens@linux.ibm.com

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-25 12:07:01 -05:00
Christophe Leroy
bc82c38a69 tracing: Uninline trace_trigger_soft_disabled() partly
On a powerpc32 build with CONFIG_CC_OPTIMISE_FOR_SIZE, the inline
keyword is not honored and trace_trigger_soft_disabled() appears
approx 50 times in vmlinux.

Adding -Winline to the build, the following message appears:

	./include/linux/trace_events.h:712:1: error: inlining failed in call to 'trace_trigger_soft_disabled': call is unlikely and code size would grow [-Werror=inline]

That function is rather big for an inlined function:

	c003df60 <trace_trigger_soft_disabled>:
	c003df60:	94 21 ff f0 	stwu    r1,-16(r1)
	c003df64:	7c 08 02 a6 	mflr    r0
	c003df68:	90 01 00 14 	stw     r0,20(r1)
	c003df6c:	bf c1 00 08 	stmw    r30,8(r1)
	c003df70:	83 e3 00 24 	lwz     r31,36(r3)
	c003df74:	73 e9 01 00 	andi.   r9,r31,256
	c003df78:	41 82 00 10 	beq     c003df88 <trace_trigger_soft_disabled+0x28>
	c003df7c:	38 60 00 00 	li      r3,0
	c003df80:	39 61 00 10 	addi    r11,r1,16
	c003df84:	4b fd 60 ac 	b       c0014030 <_rest32gpr_30_x>
	c003df88:	73 e9 00 80 	andi.   r9,r31,128
	c003df8c:	7c 7e 1b 78 	mr      r30,r3
	c003df90:	41 a2 00 14 	beq     c003dfa4 <trace_trigger_soft_disabled+0x44>
	c003df94:	38 c0 00 00 	li      r6,0
	c003df98:	38 a0 00 00 	li      r5,0
	c003df9c:	38 80 00 00 	li      r4,0
	c003dfa0:	48 05 c5 f1 	bl      c009a590 <event_triggers_call>
	c003dfa4:	73 e9 00 40 	andi.   r9,r31,64
	c003dfa8:	40 82 00 28 	bne     c003dfd0 <trace_trigger_soft_disabled+0x70>
	c003dfac:	73 ff 02 00 	andi.   r31,r31,512
	c003dfb0:	41 82 ff cc 	beq     c003df7c <trace_trigger_soft_disabled+0x1c>
	c003dfb4:	80 01 00 14 	lwz     r0,20(r1)
	c003dfb8:	83 e1 00 0c 	lwz     r31,12(r1)
	c003dfbc:	7f c3 f3 78 	mr      r3,r30
	c003dfc0:	83 c1 00 08 	lwz     r30,8(r1)
	c003dfc4:	7c 08 03 a6 	mtlr    r0
	c003dfc8:	38 21 00 10 	addi    r1,r1,16
	c003dfcc:	48 05 6f 6c 	b       c0094f38 <trace_event_ignore_this_pid>
	c003dfd0:	38 60 00 01 	li      r3,1
	c003dfd4:	4b ff ff ac 	b       c003df80 <trace_trigger_soft_disabled+0x20>

However it is located in a hot path so inlining it is important.
But forcing inlining of the entire function by using __always_inline
leads to increasing the text size by approx 20 kbytes.

Instead, split the fonction in two parts, one part with the likely
fast path, flagged __always_inline, and a second part out of line.

With this change, on a powerpc32 with CONFIG_CC_OPTIMISE_FOR_SIZE
vmlinux text increases by only 1,4 kbytes, which is partly
compensated by a decrease of vmlinux data by 7 kbytes.

On ppc64_defconfig which has CONFIG_CC_OPTIMISE_FOR_SPEED, this
change reduces vmlinux text by more than 30 kbytes.

Link: https://lkml.kernel.org/r/69ce0986a52d026d381d612801d978aa4f977460.1644563295.git.christophe.leroy@csgroup.eu

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-25 12:07:01 -05:00
Steven Rostedt (Google)
b61edd5774 eprobes: Remove redundant event type information
Currently, the event probes save the type of the event they are attached
to when recording the event. For example:

  # echo 'e:switch sched/sched_switch prev_state=$prev_state prev_prio=$prev_prio next_pid=$next_pid next_prio=$next_prio' > dynamic_events
  # cat events/eprobes/switch/format

 name: switch
 ID: 1717
 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:unsigned int __probe_type;        offset:8;       size:4; signed:0;
        field:u64 prev_state;   offset:12;      size:8; signed:0;
        field:u64 prev_prio;    offset:20;      size:8; signed:0;
        field:u64 next_pid;     offset:28;      size:8; signed:0;
        field:u64 next_prio;    offset:36;      size:8; signed:0;

 print fmt: "(%u) prev_state=0x%Lx prev_prio=0x%Lx next_pid=0x%Lx next_prio=0x%Lx", REC->__probe_type, REC->prev_state, REC->prev_prio, REC->next_pid, REC->next_prio

The __probe_type adds 4 bytes to every event.

One of the reasons for creating eprobes is to limit what is traced in an
event to be able to limit what is written into the ring buffer. Having
this redundant 4 bytes to every event takes away from this.

The event that is recorded can be retrieved from the event probe itself,
that is available when the trace is happening. For user space tools, it
could simply read the dynamic_event file to find the event they are for.
So there is really no reason to write this information into the ring
buffer for every event.

Link: https://lkml.kernel.org/r/20220218190057.2f5a19a8@gandalf.local.home

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Joel Fernandes <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-25 12:07:01 -05:00
Steven Rostedt (Google)
302e9edd54 tracing: Have traceon and traceoff trigger honor the instance
If a trigger is set on an event to disable or enable tracing within an
instance, then tracing should be disabled or enabled in the instance and
not at the top level, which is confusing to users.

Link: https://lkml.kernel.org/r/20220223223837.14f94ec3@rorschach.local.home

Cc: stable@vger.kernel.org
Fixes: ae63b31e4d ("tracing: Separate out trace events from global variables")
Tested-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-25 12:06:45 -05:00
Daniel Bristot de Oliveira
ce33c845b0 tracing: Dump stacktrace trigger to the corresponding instance
The stacktrace event trigger is not dumping the stacktrace to the instance
where it was enabled, but to the global "instance."

Use the private_data, pointing to the trigger file, to figure out the
corresponding trace instance, and use it in the trigger action, like
snapshot_trigger does.

Link: https://lkml.kernel.org/r/afbb0b4f18ba92c276865bc97204d438473f4ebc.1645396236.git.bristot@kernel.org

Cc: stable@vger.kernel.org
Fixes: ae63b31e4d ("tracing: Separate out trace events from global variables")
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Tested-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-24 22:07:03 -05:00
JaeSang Yoo
3203ce39ac tracing: Fix tp_printk option related with tp_printk_stop_on_boot
The kernel parameter "tp_printk_stop_on_boot" starts with "tp_printk" which is
the same as another kernel parameter "tp_printk". If "tp_printk" setup is
called before the "tp_printk_stop_on_boot", it will override the latter
and keep it from being set.

This is similar to other kernel parameter issues, such as:
  Commit 745a600cf1 ("um: console: Ignore console= option")
or init/do_mounts.c:45 (setup function of "ro" kernel param)

Fix it by checking for a "_" right after the "tp_printk" and if that
exists do not process the parameter.

Link: https://lkml.kernel.org/r/20220208195421.969326-1-jsyoo5b@gmail.com

Signed-off-by: JaeSang Yoo <jsyoo5b@gmail.com>
[ Fixed up change log and added space after if condition ]
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-08 15:47:00 -05:00
Tom Zanussi
67ab5eb71b tracing: Don't inc err_log entry count if entry allocation fails
tr->n_err_log_entries should only be increased if entry allocation
succeeds.

Doing it when it fails won't cause any problems other than wasting an
entry, but should be fixed anyway.

Link: https://lkml.kernel.org/r/cad1ab28f75968db0f466925e7cba5970cec6c29.1643319703.git.zanussi@kernel.org

Cc: stable@vger.kernel.org
Fixes: 2f754e771b ("tracing: Don't inc err_log entry count if entry allocation fails")
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-01-27 19:15:49 -05:00
Tom Zanussi
097f1eefed tracing: Propagate is_signed to expression
During expression parsing, a new expression field is created which
should inherit the properties of the operands, such as size and
is_signed.

is_signed propagation was missing, causing spurious errors with signed
operands.  Add it in parse_expr() and parse_unary() to fix the problem.

Link: https://lkml.kernel.org/r/f4dac08742fd7a0920bf80a73c6c44042f5eaa40.1643319703.git.zanussi@kernel.org

Cc: stable@vger.kernel.org
Fixes: 100719dcef ("tracing: Add simple expression support to hist triggers")
Reported-by: Yordan Karadzhov <ykaradzhov@vmware.com>
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215513
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-01-27 19:15:49 -05:00
Tom Zanussi
b59f2f2b86 tracing: Fix smatch warning for do while check in event_hist_trigger_parse()
The patch ec5ce09875: "tracing: Allow whitespace to surround hist
trigger filter" from Jan 15, 2018, leads to the following Smatch
static checker warning:

    kernel/trace/trace_events_hist.c:6199 event_hist_trigger_parse()
    warn: 'p' can't be NULL.

Since p is always checked for a NULL value at the top of loop and
nothing in the rest of the loop will set it to NULL, the warning
is correct and might as well be 1 to silence the warning.

Link: https://lkml.kernel.org/r/a1d4c79766c0cf61e20438dc35244d216633fef6.1643319703.git.zanussi@kernel.org

Fixes: ec5ce09875 ("tracing: Allow whitespace to surround hist trigger filter")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-01-27 19:15:48 -05:00
Tom Zanussi
798a5b6c19 tracing: Fix smatch warning for null glob in event_hist_trigger_parse()
The recent rename of event_hist_trigger_parse() caused smatch
re-evaluation of trace_events_hist.c and as a result an old warning
was found:

    kernel/trace/trace_events_hist.c:6174 event_hist_trigger_parse()
    error: we previously assumed 'glob' could be null (see line 6166)

glob should never be null (and apparently smatch can also figure that
out and skip the warning when using the cross-function DB (but which
can't be used with a 0day build as it takes too much time to
generate)).

Nonetheless for clarity, remove the test but add a WARN_ON() in case
the code ever changes.

Link: https://lkml.kernel.org/r/96925e5c1f116654ada7ea0613d930b1266b5e1c.1643319703.git.zanussi@kernel.org

Fixes: f404da6e1d ("tracing: Add 'last error' error facility for hist triggers")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-01-27 19:15:47 -05:00
Xiaoke Wang
e629e7b525 tracing/histogram: Fix a potential memory leak for kstrdup()
kfree() is missing on an error path to free the memory allocated by
kstrdup():

  p = param = kstrdup(data->params[i], GFP_KERNEL);

So it is better to free it via kfree(p).

Link: https://lkml.kernel.org/r/tencent_C52895FD37802832A3E5B272D05008866F0A@qq.com

Cc: stable@vger.kernel.org
Fixes: d380dcde9a ("tracing: Fix now invalid var_ref_vals assumption in trace action")
Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-01-27 19:15:44 -05:00
Steven Rostedt (Google)
4ed308c445 ftrace: Have architectures opt-in for mcount build time sorting
First S390 complained that the sorting of the mcount sections at build
time caused the kernel to crash on their architecture. Now PowerPC is
complaining about it too. And also ARM64 appears to be having issues.

It may be necessary to also update the relocation table for the values
in the mcount table. Not only do we have to sort the table, but also
update the relocations that may be applied to the items in the table.

If the system is not relocatable, then it is fine to sort, but if it is,
some architectures may have issues (although x86 does not as it shifts all
addresses the same).

Add a HAVE_BUILDTIME_MCOUNT_SORT that an architecture can set to say it is
safe to do the sorting at build time.

Also update the config to compile in build time sorting in the sorttable
code in scripts/ to depend on CONFIG_BUILDTIME_MCOUNT_SORT.

Link: https://lore.kernel.org/all/944D10DA-8200-4BA9-8D0A-3BED9AA99F82@linux.ibm.com/
Link: https://lkml.kernel.org/r/20220127153821.3bc1ac6e@gandalf.local.home

Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Yinan Liu <yinan@linux.alibaba.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Reported-by: Sachin Sant <sachinp@linux.ibm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com> [arm64]
Tested-by: Sachin Sant <sachinp@linux.ibm.com>
Fixes: 72b3942a17 ("scripts: ftrace - move the sort-processing in ftrace_init")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-01-27 19:15:44 -05:00
Linus Torvalds
67bfce0e01 Merge tag 'trace-v5.17-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull ftrace fix from Steven Rostedt:
 "Fix s390 breakage from sorting mcount tables.

  The latest merge of the tracing tree sorts the mcount table at build
  time. But s390 appears to do things differently (like always) and
  replaces the sorted table back to the original unsorted one. As the
  ftrace algorithm depends on it being sorted, bad things happen when it
  is not, and s390 experienced those bad things.

  Add a new config to tell the boot if the mcount table is sorted or
  not, and allow s390 to opt out of it"

* tag 'trace-v5.17-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Fix assuming build time sort works for s390
2022-01-23 08:07:02 +02:00
Steven Rostedt (Google)
6b9b641370 ftrace: Fix assuming build time sort works for s390
To speed up the boot process, as mcount_loc needs to be sorted for ftrace
to work properly, sorting it at build time is more efficient than boot up
and can save milliseconds of time. Unfortunately, this change broke s390
as it will modify the mcount_loc location after the sorting takes place
and will put back the unsorted locations. Since the sorting is skipped at
boot up if it is believed that it was sorted at run time, ftrace can crash
as its algorithms are dependent on the list being sorted.

Add a new config BUILDTIME_MCOUNT_SORT that is set when
BUILDTIME_TABLE_SORT but not if S390 is set. Use this config to determine
if sorting should take place at boot up.

Link: https://lore.kernel.org/all/yt9dee51ctfn.fsf@linux.ibm.com/

Fixes: 72b3942a17 ("scripts: ftrace - move the sort-processing in ftrace_init")
Reported-by: Sven Schnelle <svens@linux.ibm.com>
Tested-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-01-23 00:10:09 -05:00
Linus Torvalds
4d66020dce Merge tag 'trace-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
 "New:

   - The Real Time Linux Analysis (RTLA) tool is added to the tools
     directory.

   - Can safely filter on user space pointers with: field.ustring ~
     "match-string"

   - eprobes can now be filtered like any other event.

   - trace_marker(_raw) now uses stream_open() to allow multiple threads
     to safely write to it. Note, this could possibly break existing
     user space, but we will not know until we hear about it, and then
     can revert the change if need be.

   - New field in events to display when bottom halfs are disabled.

   - Sorting of the ftrace functions are now done at compile time
     instead of at bootup.

  Infrastructure changes to support future efforts:

   - Added __rel_loc type for trace events. Similar to __data_loc but
     the offset to the dynamic data is based off of the location of the
     descriptor and not the beginning of the event. Needed for user
     defined events.

   - Some simplification of event trigger code.

   - Make synthetic events process its callback better to not hinder
     other event callbacks that are registered. Needed for user defined
     events.

  And other small fixes and cleanups"

* tag 'trace-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (50 commits)
  tracing: Add ustring operation to filtering string pointers
  rtla: Add rtla timerlat hist documentation
  rtla: Add rtla timerlat top documentation
  rtla: Add rtla timerlat documentation
  rtla: Add rtla osnoise hist documentation
  rtla: Add rtla osnoise top documentation
  rtla: Add rtla osnoise man page
  rtla: Add Documentation
  rtla/timerlat: Add timerlat hist mode
  rtla: Add timerlat tool and timelart top mode
  rtla/osnoise: Add the hist mode
  rtla/osnoise: Add osnoise top mode
  rtla: Add osnoise tool
  rtla: Helper functions for rtla
  rtla: Real-Time Linux Analysis tool
  tracing/osnoise: Properly unhook events if start_per_cpu_kthreads() fails
  tracing: Remove duplicate warnings when calling trace_create_file()
  tracing/kprobes: 'nmissed' not showed correctly for kretprobe
  tracing: Add test for user space strings when filtering on string pointers
  tracing: Have syscall trace events use trace_event_buffer_lock_reserve()
  ...
2022-01-16 10:15:32 +02:00
Linus Torvalds
f56caedaf9 Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:
 "146 patches.

  Subsystems affected by this patch series: kthread, ia64, scripts,
  ntfs, squashfs, ocfs2, vfs, and mm (slab-generic, slab, kmemleak,
  dax, kasan, debug, pagecache, gup, shmem, frontswap, memremap,
  memcg, selftests, pagemap, dma, vmalloc, memory-failure, hugetlb,
  userfaultfd, vmscan, mempolicy, oom-kill, hugetlbfs, migration, thp,
  ksm, page-poison, percpu, rmap, zswap, zram, cleanups, hmm, and
  damon)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (146 commits)
  mm/damon: hide kernel pointer from tracepoint event
  mm/damon/vaddr: hide kernel pointer from damon_va_three_regions() failure log
  mm/damon/vaddr: use pr_debug() for damon_va_three_regions() failure logging
  mm/damon/dbgfs: remove an unnecessary variable
  mm/damon: move the implementation of damon_insert_region to damon.h
  mm/damon: add access checking for hugetlb pages
  Docs/admin-guide/mm/damon/usage: update for schemes statistics
  mm/damon/dbgfs: support all DAMOS stats
  Docs/admin-guide/mm/damon/reclaim: document statistics parameters
  mm/damon/reclaim: provide reclamation statistics
  mm/damon/schemes: account how many times quota limit has exceeded
  mm/damon/schemes: account scheme actions that successfully applied
  mm/damon: remove a mistakenly added comment for a future feature
  Docs/admin-guide/mm/damon/usage: update for kdamond_pid and (mk|rm)_contexts
  Docs/admin-guide/mm/damon/usage: mention tracepoint at the beginning
  Docs/admin-guide/mm/damon/usage: remove redundant information
  Docs/admin-guide/mm/damon/usage: update for scheme quotas and watermarks
  mm/damon: convert macro functions to static inline functions
  mm/damon: modify damon_rand() macro to static inline function
  mm/damon: move damon_rand() definition into damon.h
  ...
2022-01-15 20:37:06 +02:00
Cai Huoqing
ff78f6679d trace/hwlat: make use of the helper function kthread_run_on_cpu()
Replace kthread_create_on_cpu/wake_up_process() with kthread_run_on_cpu()
to simplify the code.

Link: https://lkml.kernel.org/r/20211022025711.3673-7-caihuoqing@baidu.com
Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Cc: Bernard Metzler <bmt@zurich.ibm.com>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-15 16:30:24 +02:00