4052 Commits

Author SHA1 Message Date
Steven Rostedt (VMware)
4a1221feb4 [ALPS06674756] tracing: Do not stop recording comms if the trace file is
commit 4fdd595e upstream.

A while ago, when the "trace" file was opened, tracing was stopped, and
code was added to stop recording the comms to saved_cmdlines, for mapping
of the pids to the task name.

Code has been added that only records the comm if a trace event occurred,
and theres no reason to not trace it if the trace file is opened.

MTK-Commit-Id: 9db52c2ad420f80e6e0582383500cfd1a8288a9d

Cc: stable@vger.kernel.org
Fixes: 7ffbd48d5c ("tracing: Cache comms only after an event occurred")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Feature: IRQ Monitor
CR-Id: ALPS06674756
Signed-off-by: Andress Kuo <andress.kuo@mediatek.com>
Change-Id: I77778e641c81251d526a273ffdcd19018ed9dbad
2022-02-24 14:23:34 +08:00
Steven Rostedt (VMware)
a05c5ea397 [ALPS06674756] tracing: Do not stop recording cmdlines when tracing is off
commit 85550c83 upstream.

The saved_cmdlines is used to map pids to the task name, such that the
output of the tracing does not just show pids, but also gives a human
readable name for the task.

If the name is not mapped, the output looks like this:

    <...>-1316          [005] ...2   132.044039: ...

Instead of this:

    gnome-shell-1316    [005] ...2   132.044039: ...

The names are updated when tracing is running, but are skipped if tracing
is stopped. Unfortunately, this stops the recording of the names if the
top level tracer is stopped, and not if theres other tracers active.

The recording of a name only happens when a new event is written into a
ring buffer, so there is no need to test if tracing is on or not. If
tracing is off, then no event is written and no need to test if tracing is
off or not.

Remove the check, as it hides the names of tasks for events in the
instance buffers.

MTK-Commit-Id: 71a131a2e52646a118a4f91e2b82d81b25e3090b

Cc: stable@vger.kernel.org
Fixes: 7ffbd48d5c ("tracing: Cache comms only after an event occurred")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Feature: IRQ Monitor
CR-Id: ALPS06674756
Signed-off-by: Andress Kuo <andress.kuo@mediatek.com>
Change-Id: I5c05279a0f9f3c58ce02d1142935f799ffdfbad1
2022-02-24 14:23:33 +08:00
Liangyan
5277bc51d1 [ALPS06617525] tracing: Correct the length check
which causes memory corruption

commit 3e08a9f97 upstream.

Weve suffered from severe kernel crashes due to memory corruption on
our production environment, like,

Call Trace:
[1640542.554277] general protection fault: 0000 [#1] SMP PTI
[1640542.554856] CPU: 17 PID: 26996 Comm: python Kdump: loaded Tainted:G
[1640542.556629] RIP: 0010:kmem_cache_alloc+0x90/0x190
[1640542.559074] RSP: 0018:ffffb16faa597df8 EFLAGS: 00010286
[1640542.559587] RAX: 0000000000000000 RBX: 0000000000400200 RCX:
0000000006e931bf
[1640542.560323] RDX: 0000000006e931be RSI: 0000000000400200 RDI:
ffff9a45ff004300
[1640542.560996] RBP: 0000000000400200 R08: 0000000000023420 R09:
0000000000000000
[1640542.561670] R10: 0000000000000000 R11: 0000000000000000 R12:
ffffffff9a20608d
[1640542.562366] R13: ffff9a45ff004300 R14: ffff9a45ff004300 R15:
696c662f65636976
[1640542.563128] FS:  00007f45d7c6f740(0000) GS:ffff9a45ff840000(0000)
knlGS:0000000000000000
[1640542.563937] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[1640542.564557] CR2: 00007f45d71311a0 CR3: 000000189d63e004 CR4:
00000000003606e0
[1640542.565279] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[1640542.566069] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
0000000000000400
[1640542.566742] Call Trace:
[1640542.567009]  anon_vma_clone+0x5d/0x170
[1640542.567417]  __split_vma+0x91/0x1a0
[1640542.567777]  do_munmap+0x2c6/0x320
[1640542.568128]  vm_munmap+0x54/0x70
[1640542.569990]  __x64_sys_munmap+0x22/0x30
[1640542.572005]  do_syscall_64+0x5b/0x1b0
[1640542.573724]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[1640542.575642] RIP: 0033:0x7f45d6e61e27

James Wang has reproduced it stably on the latest 4.19 LTS.
After some debugging, we finally proved that its due to ftrace
buffer out-of-bound access using a debug tool as follows:
[   86.775200] BUG: Out-of-bounds write at addr 0xffff88aefe8b7000
[   86.780806]  no_context+0xdf/0x3c0
[   86.784327]  __do_page_fault+0x252/0x470
[   86.788367]  do_page_fault+0x32/0x140
[   86.792145]  page_fault+0x1e/0x30
[   86.795576]  strncpy_from_unsafe+0x66/0xb0
[   86.799789]  fetch_memory_string+0x25/0x40
[   86.804002]  fetch_deref_string+0x51/0x60
[   86.808134]  kprobe_trace_func+0x32d/0x3a0
[   86.812347]  kprobe_dispatcher+0x45/0x50
[   86.816385]  kprobe_ftrace_handler+0x90/0xf0
[   86.820779]  ftrace_ops_assist_func+0xa1/0x140
[   86.825340]  0xffffffffc00750bf
[   86.828603]  do_sys_open+0x5/0x1f0
[   86.832124]  do_syscall_64+0x5b/0x1b0
[   86.835900]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

commit b220c049d519 ("tracing: Check length before giving out
the filter buffer") adds length check to protect trace data
overflow introduced in 0fc1b09ff1, seems that this fix cant prevent
overflow entirely, the length check should also take the sizeof
entry->array[0] into account, since this array[0] is filled the
length of trace data and occupy addtional space and risk overflow.

Link: https://lkml.kernel.org/r/20210607125734.
1770447-1-liangyan.peng@linux.alibaba.com

MTK-Commit-Id: c1f708ceb78fd732f45f8f1f1a7cb28bdeb3ff13

Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Xunlei Pang <xlpang@linux.alibaba.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixes: b220c049d519 ("tracing: Check length before giving...")
Reviewed-by: Xunlei Pang <xlpang@linux.alibaba.com>
Reviewed-by: yinbinbin <yinbinbin@alibabacloud.com>
Reviewed-by: Wetp Zhang <wetp.zy@linux.alibaba.com>
Tested-by: James Wang <jnwang@linux.alibaba.com>
Signed-off-by: Liangyan <liangyan.peng@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Feature: IRQ Monitor
CR-Id: ALPS06617525
Signed-off-by: Andress Kuo <andress.kuo@mediatek.com>
Change-Id: Id08247e77701db9f5e81b63baa7563c0e61e371b
2022-02-10 17:47:58 +08:00
Naveen N. Rao
924d60c7e6 [ALPS06492893] tracing: Fix check for trace_percpu_buffer validity
With the new osnoise tracer, we are seeing the below splat:
Kernel attempted to read user page (c7d880000) - exploit attempt? (uid: 0)
BUG: Unable to handle kernel data access on read at 0xc7d880000
Faulting instruction address: 0xc0000000002ffa10
Oops: Kernel access of bad area, sig: 11 [#1]
LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
    ...
    NIP [c0000000002ffa10] __trace_array_vprintk.part.0+0x70/0x2f0
    LR [c0000000002ff9fc] __trace_array_vprintk.part.0+0x5c/0x2f0
    Call Trace:
    [c0000008bdd73b80] [c0000000001c49cc] put_prev_task_fair
    [c0000008bdd73be0] [c000000000301430] trace_array_printk_buf
    [c0000008bdd73c00] [c0000000003178b0] trace_sched_switch_callback
    [c0000008bdd73c90] [c000000000e70d60] __schedule+0x410/0x710
    [c0000008bdd73d40] [c000000000e710c0] schedule+0x60/0x130
    [c0000008bdd73d70] [c000000000030614] interrupt_exit_user_prepare_main
    [c0000008bdd73de0] [c000000000030a70] syscall_exit_prepare
    [c0000008bdd73e10] [c00000000000c174] system_call_vectored_common

osnoise tracer on ppc64le is triggering osnoise_taint() for negative
duration in get_int_safe_duration() called from
trace_sched_switch_callback()->thread_exit().

The problem though is that the check for a valid trace_percpu_buffer is
incorrect in get_trace_buf(). The check is being done after calculating
the pointer for the current cpu, rather than on the main percpu pointer.
Fix the check to be against trace_percpu_buffer.

Link: https://lkml.kernel.org/r/a920e4272e0b0635cf20c444707cbce1b2c8973d.
1640255304.git.naveen.n.rao@linux.vnet.ibm.com

MTK-Commit-Id: ee8ee86321eac59ca3fd61a68183441928b6a852

Cc: stable@vger.kernel.org
Fixes: e2ace00117 ("tracing: Choose static tp_printk buffer by
explicit nesting count")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Change-Id: I7f6ec72acf4067a29499237cf2dd64a0969d5f14
Feature: IRQ Monitor
CR-Id: ALPS06492893
Signed-off-by: Andress Kuo <andress.kuo@mediatek.com>
2022-01-20 11:24:05 +08:00
Bo Ye
425c4a3572 [ALPS06486924] ACK: Merge android-4.19-stable into alps-mp-s0.mp1
Target:
   android-4.19-stable "011b73c995f35959b39ccde045addbc1862fa3e6
   Merge 4.19.191 into android-4.19-stable"

Version change from 4.19.188 to 4.19.191

MTK-Commit-Id: c8384f99d5a155550b3c0707800ea3d1d83f9ee3

Feature: Kernel SI Operation
CR-Id: ALPS06486924
Signed-off-by: Bo Ye <bo.ye@mediatek.com>
Change-Id: Ic51822fa66c2d94e5f60b2e65a65153ade20c228
2022-01-20 11:18:48 +08:00
ot_dick.yang
874ed009ee [ALPS06396594] tracing: Fix bug in rb_per_cpu_empty() that might cause
deadloop

The "rb_per_cpu_empty()" misinterpret the condition (as not-empty) when
"head_page" and "commit_page" of "struct ring_buffer_per_cpu" points to
the same buffer page, whose "buffer_data_page" is empty and "read" field
is non-zero.

An error scenario could be constructed as followed (kernel perspective):

1. All pages in the buffer has been accessed by reader(s) so that all of
them will have non-zero "read" field.

2. Read and clear all buffer pages so that "rb_num_of_entries()" will
return 0 rendering theres no more data to read. It is also required
that the "read_page", "commit_page" and "tail_page" points to the same
page, while "head_page" is the next page of them.

3. Invoke "ring_buffer_lock_reserve()" with large enough "length"
so that it shot pass the end of current tail buffer page. Now the
"head_page", "commit_page" and "tail_page" points to the same page.

4. Discard current event with "ring_buffer_discard_commit()", so that
"head_page", "commit_page" and "tail_page" points to a page whose buffer
data page is now empty.

When the error scenario has been constructed, "tracing_read_pipe" will
be trapped inside a deadloop: "trace_empty()" returns 0 since
"rb_per_cpu_empty()" returns 0 when it hits the CPU containing such
constructed ring buffer. Then "trace_find_next_entry_inc()" always
return NULL since "rb_num_of_entries()" reports theres no more entry
to read. Finally "trace_seq_to_user()" returns "-EBUSY" spanking
"tracing_read_pipe" back to the start of the "waitagain" loop.

Ive also written a proof-of-concept script to construct the scenario
and trigger the bug automatically, you can use it to trace and validate
my reasoning above:

  https://github.com/aegistudio/RingBufferDetonator.git

Tests has been carried out on linux kernel 5.14-rc2
(2734d6c1b1a089fb593ef6a23d4b70903526fe0c), my fixed version
of kernel (for testing whether my update fixes the bug) and
some older kernels (for range of affected kernels). Test result is
also attached to the proof-of-concept repository.

Link: https://lore.kernel.org/linux-trace-devel/YPaNxsIlb2yjSi5Y@aegistudio/
Link: https://lore.kernel.org/linux-trace-devel/YPgrN85WL9VyrZ55@aegistudio

MTK-Commit-Id: a6aaf46f366ee79c91f87e3bd990c8d1bb38d836

Cc: stable@vger.kernel.org
Fixes: bf41a158ca ("ring-buffer: make reentrant")
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Signed-off-by: Haoran Luo <www@aegistudio.net>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: ot_dick.yang <ot_dick.yang@mediatek.com>
CR-Id: ALPS06396594
Feature: [Module]Schedule Monitor
Change-Id: I9d9709e811161592c8f1d847ac44e640a73d6cdb
2021-12-05 11:24:27 +08:00
bo.ye
c44ad28aa0 [ALPS05707974] [Do NOT Sync]Merge branch android-4.19-stable into alps-trunk-s0.basic
[Detail]
	Target: 6b79701b0a

MTK-Commit-Id: 2b5bc62102377ec37334ad041b9fbf4f6347c98c

Feature: Others
CR-Id: ALPS05707974
Signed-off-by: Breeze Li <Breeze.Li@mediatek.com>
Change-Id: I81d5539f1fde4f8665a0d36efee58eee540535e3
2021-05-13 12:33:11 +08:00
Greg Kroah-Hartman
8c62f42548 Merge 4.19.185 into android-4.19-stable
Changes in 4.19.185
	selinux: vsock: Set SID for socket returned by accept()
	tcp: relookup sock for RST+ACK packets handled by obsolete req sock
	ipv6: weaken the v4mapped source check
	ext4: fix bh ref count on error paths
	rpc: fix NULL dereference on kmalloc failure
	ASoC: rt5640: Fix dac- and adc- vol-tlv values being off by a factor of 10
	ASoC: rt5651: Fix dac- and adc- vol-tlv values being off by a factor of 10
	ASoC: sgtl5000: set DAP_AVC_CTRL register to correct default value on probe
	ASoC: es8316: Simplify adc_pga_gain_tlv table
	ASoC: cs42l42: Fix Bitclock polarity inversion
	ASoC: cs42l42: Fix channel width support
	ASoC: cs42l42: Fix mixer volume control
	ASoC: cs42l42: Always wait at least 3ms after reset
	vhost: Fix vhost_vq_reset()
	scsi: st: Fix a use after free in st_open()
	scsi: qla2xxx: Fix broken #endif placement
	staging: comedi: cb_pcidas: fix request_irq() warn
	staging: comedi: cb_pcidas64: fix request_irq() warn
	ASoC: rt5659: Update MCLK rate in set_sysclk()
	thermal/core: Add NULL pointer check before using cooling device stats
	locking/ww_mutex: Simplify use_ww_ctx & ww_ctx handling
	ext4: do not iput inode under running transaction in ext4_rename()
	brcmfmac: clear EAP/association status bits on linkdown events
	ath10k: hold RCU lock when calling ieee80211_find_sta_by_ifaddr()
	net: ethernet: aquantia: Handle error cleanup of start on open
	appletalk: Fix skb allocation size in loopback case
	net: wan/lmc: unregister device when no matching device is found
	bpf: Remove MTU check in __bpf_skb_max_len
	ALSA: usb-audio: Apply sample rate quirk to Logitech Connect
	ALSA: hda/realtek: fix a determine_headset_type issue for a Dell AIO
	ALSA: hda/realtek: call alc_update_headset_mode() in hp_automute_hook
	PM: runtime: Fix race getting/putting suppliers at probe
	PM: runtime: Fix ordering in pm_runtime_get_suppliers()
	tracing: Fix stack trace event size
	mm: fix race by making init_zero_pfn() early_initcall
	drm/amdgpu: fix offset calculation in amdgpu_vm_bo_clear_mappings()
	drm/amdgpu: check alignment on CPU page for bo map
	reiserfs: update reiserfs_xattrs_initialized() condition
	pinctrl: rockchip: fix restore error in resume
	extcon: Add stubs for extcon_register_notifier_all() functions
	extcon: Fix error handling in extcon_dev_register
	firewire: nosy: Fix a use-after-free bug in nosy_ioctl()
	usbip: vhci_hcd fix shift out-of-bounds in vhci_hub_control()
	USB: quirks: ignore remote wake-up on Fibocom L850-GL LTE modem
	usb: musb: Fix suspend with devices connected for a64
	usb: xhci-mtk: fix broken streams issue on 0.96 xHCI
	cdc-acm: fix BREAK rx code path adding necessary calls
	USB: cdc-acm: untangle a circular dependency between callback and softint
	USB: cdc-acm: downgrade message to debug
	USB: cdc-acm: fix double free on probe failure
	USB: cdc-acm: fix use-after-free after probe failure
	usb: gadget: udc: amd5536udc_pci fix null-ptr-dereference
	usb: dwc2: Fix HPRT0.PrtSusp bit setting for HiKey 960 board.
	staging: rtl8192e: Fix incorrect source in memcpy()
	staging: rtl8192e: Change state information from u16 to u8
	drivers: video: fbcon: fix NULL dereference in fbcon_cursor()
	Linux 4.19.185

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I65f4fd7d1b60193895371093882ab33943d22e7c
2021-04-07 14:37:10 +02:00
Steven Rostedt (VMware)
5363e9b9aa tracing: Fix stack trace event size
commit 9deb193af69d3fd6dd8e47f292b67c805a787010 upstream.

Commit cbc3b92ce037 fixed an issue to modify the macros of the stack trace
event so that user space could parse it properly. Originally the stack
trace format to user space showed that the called stack was a dynamic
array. But it is not actually a dynamic array, in the way that other
dynamic event arrays worked, and this broke user space parsing for it. The
update was to make the array look to have 8 entries in it. Helper
functions were added to make it parse it correctly, as the stack was
dynamic, but was determined by the size of the event stored.

Although this fixed user space on how it read the event, it changed the
internal structure used for the stack trace event. It changed the array
size from [0] to [8] (added 8 entries). This increased the size of the
stack trace event by 8 words. The size reserved on the ring buffer was the
size of the stack trace event plus the number of stack entries found in
the stack trace. That commit caused the amount to be 8 more than what was
needed because it did not expect the caller field to have any size. This
produced 8 entries of garbage (and reading random data) from the stack
trace event:

          <idle>-0       [002] d... 1976396.837549: <stack trace>
 => trace_event_raw_event_sched_switch
 => __traceiter_sched_switch
 => __schedule
 => schedule_idle
 => do_idle
 => cpu_startup_entry
 => secondary_startup_64_no_verify
 => 0xc8c5e150ffff93de
 => 0xffff93de
 => 0
 => 0
 => 0xc8c5e17800000000
 => 0x1f30affff93de
 => 0x00000004
 => 0x200000000

Instead, subtract the size of the caller field from the size of the event
to make sure that only the amount needed to store the stack trace is
reserved.

Link: https://lore.kernel.org/lkml/your-ad-here.call-01617191565-ext-9692@work.hours/

Cc: stable@vger.kernel.org
Fixes: cbc3b92ce037 ("tracing: Set kernel_stack's caller size properly")
Reported-by: Vasily Gorbik <gor@linux.ibm.com>
Tested-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-07 12:48:49 +02:00
bo.ye
47a12e27d4 [ALPS05605552] [Do NOT Sync]Merge branch android-4.19-stable into alps-trunk-s0.basic
[Detail]
	Target: 6455a150fa

MTK-Commit-Id: be087bb0eac18562d6f27698ba757518c211c455

Feature: Others
CR-Id: ALPS05605552
Signed-off-by: Breeze Li <Breeze.Li@mediatek.com>
Change-Id: I02fa3f0c7bca8d81e7a332e70032e209619040c1
2021-03-19 00:18:59 +08:00
bo.ye
f1ab89877c [ALPS05557158] [Do NOT Sync]Merge branch android-4.19-stable into alps-trunk-s0.basic
[Detail]
	Target: d084fe8b5d

MTK-Commit-Id: caa5fc883035ab9f591f3a912186fe2b9e4df31a

Feature: Others
Change-Id: If2337ec63740de3f3d272eb8271b798d55cbc441
CR-Id: ALPS05557158
Signed-off-by: Breeze Li <Breeze.Li@mediatek.com>
2021-03-05 11:57:05 +08:00
Greg Kroah-Hartman
bce09d96d6 Merge 4.19.177 into android-4.19-stable
Changes in 4.19.177
	tracing: Do not count ftrace events in top level enable output
	tracing: Check length before giving out the filter buffer
	arm/xen: Don't probe xenbus as part of an early initcall
	arm64: dts: rockchip: Fix PCIe DT properties on rk3399
	platform/x86: hp-wmi: Disable tablet-mode reporting by default
	ovl: perform vfs_getxattr() with mounter creds
	cap: fix conversions on getxattr
	ovl: skip getxattr of security labels
	drm/amd/display: Fix dc_sink kref count in emulated_link_detect
	drm/amd/display: Free atomic state after drm_atomic_commit
	riscv: virt_addr_valid must check the address belongs to linear mapping
	bfq-iosched: Revert "bfq: Fix computation of shallow depth"
	ARM: dts: lpc32xx: Revert set default clock rate of HCLK PLL
	ARM: ensure the signal page contains defined contents
	ARM: kexec: fix oops after TLB are invalidated
	mt76: dma: fix a possible memory leak in mt76_add_fragment()
	bpf: Check for integer overflow when using roundup_pow_of_two()
	netfilter: xt_recent: Fix attempt to update deleted entry
	netfilter: flowtable: fix tcp and udp header checksum update
	xen/netback: avoid race in xenvif_rx_ring_slots_available()
	net: stmmac: set TxQ mode back to DCB after disabling CBS
	netfilter: conntrack: skip identical origin tuple in same zone only
	net: hns3: add a check for queue_id in hclge_reset_vf_queue()
	firmware_loader: align .builtin_fw to 8
	i2c: stm32f7: fix configuration of the digital filter
	h8300: fix PREEMPTION build, TI_PRE_COUNT undefined
	usb: dwc3: ulpi: fix checkpatch warning
	usb: dwc3: ulpi: Replace CPU-based busyloop with Protocol-based one
	net: fix iteration for sctp transport seq_files
	net/vmw_vsock: improve locking in vsock_connect_timeout()
	net: watchdog: hold device global xmit lock during tx disable
	vsock/virtio: update credit only if socket is not closed
	vsock: fix locking in vsock_shutdown()
	net/rds: restrict iovecs length for RDS_CMSG_RDMA_ARGS
	net/qrtr: restrict user-controlled length in qrtr_tun_write_iter()
	ovl: expand warning in ovl_d_real()
	x86/build: Disable CET instrumentation in the kernel for 32-bit too
	KVM: SEV: fix double locking due to incorrect backport
	net: qrtr: Fix port ID for control messages
	Xen/x86: don't bail early from clear_foreign_p2m_mapping()
	Xen/x86: also check kernel mapping in set_foreign_p2m_mapping()
	Xen/gntdev: correct dev_bus_addr handling in gntdev_map_grant_pages()
	Xen/gntdev: correct error checking in gntdev_map_grant_pages()
	xen/arm: don't ignore return errors from set_phys_to_machine
	xen-blkback: don't "handle" error by BUG()
	xen-netback: don't "handle" error by BUG()
	xen-scsiback: don't "handle" error by BUG()
	xen-blkback: fix error handling in xen_blkbk_map()
	scsi: qla2xxx: Fix crash during driver load on big endian machines
	kvm: check tlbs_dirty directly
	Linux 4.19.177

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I5bef9024912d4568ab7ee3869072c0c4350513f5
2021-02-23 15:49:34 +01:00
Steven Rostedt (VMware)
0572fc6a51 tracing: Check length before giving out the filter buffer
commit b220c049d5196dd94d992dd2dc8cba1a5e6123bf upstream.

When filters are used by trace events, a page is allocated on each CPU and
used to copy the trace event fields to this page before writing to the ring
buffer. The reason to use the filter and not write directly into the ring
buffer is because a filter may discard the event and there's more overhead
on discarding from the ring buffer than the extra copy.

The problem here is that there is no check against the size being allocated
when using this page. If an event asks for more than a page size while being
filtered, it will get only a page, leading to the caller writing more that
what was allocated.

Check the length of the request, and if it is more than PAGE_SIZE minus the
header default back to allocating from the ring buffer directly. The ring
buffer may reject the event if its too big anyway, but it wont overflow.

Link: https://lore.kernel.org/ath10k/1612839593-2308-1-git-send-email-wgong@codeaurora.org/

Cc: stable@vger.kernel.org
Fixes: 0fc1b09ff1 ("tracing: Use temp buffer when filtering events")
Reported-by: Wen Gong <wgong@codeaurora.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-23 15:00:55 +01:00
Steven Rostedt (VMware)
334d216dfe tracing: Do not count ftrace events in top level enable output
commit 256cfdd6fdf70c6fcf0f7c8ddb0ebd73ce8f3bc9 upstream.

The file /sys/kernel/tracing/events/enable is used to enable all events by
echoing in "1", or disabling all events when echoing in "0". To know if all
events are enabled, disabled, or some are enabled but not all of them,
cating the file should show either "1" (all enabled), "0" (all disabled), or
"X" (some enabled but not all of them). This works the same as the "enable"
files in the individule system directories (like tracing/events/sched/enable).

But when all events are enabled, the top level "enable" file shows "X". The
reason is that its checking the "ftrace" events, which are special events
that only exist for their format files. These include the format for the
function tracer events, that are enabled when the function tracer is
enabled, but not by the "enable" file. The check includes these events,
which will always be disabled, and even though all true events are enabled,
the top level "enable" file will show "X" instead of "1".

To fix this, have the check test the event's flags to see if it has the
"IGNORE_ENABLE" flag set, and if so, not test it.

Cc: stable@vger.kernel.org
Fixes: 553552ce17 ("tracing: Combine event filter_active and enable into single flags field")
Reported-by: "Yordan Karadzhov (VMware)" <y.karadz@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-23 15:00:55 +01:00
Greg Kroah-Hartman
98d8ec1f71 Merge 4.19.176 into android-4.19-stable
Changes in 4.19.176
	tracing/kprobe: Fix to support kretprobe events on unloaded modules
	block: fix NULL pointer dereference in register_disk
	fgraph: Initialize tracing_graph_pause at task creation
	remoteproc: qcom_q6v5_mss: Validate modem blob firmware size before load
	remoteproc: qcom_q6v5_mss: Validate MBA firmware size before load
	af_key: relax availability checks for skb size calculation
	regulator: core: avoid regulator_resolve_supply() race condition
	chtls: Fix potential resource leak
	pNFS/NFSv4: Try to return invalid layout in pnfs_layout_process()
	iwlwifi: mvm: take mutex for calling iwl_mvm_get_sync_time()
	iwlwifi: pcie: add a NULL check in iwl_pcie_txq_unmap
	iwlwifi: pcie: fix context info memory leak
	iwlwifi: mvm: guard against device removal in reprobe
	SUNRPC: Move simple_get_bytes and simple_get_netobj into private header
	SUNRPC: Handle 0 length opaque XDR object data properly
	lib/string: Add strscpy_pad() function
	include/trace/events/writeback.h: fix -Wstringop-truncation warnings
	memcg: fix a crash in wb_workfn when a device disappears
	Fix unsynchronized access to sev members through svm_register_enc_region
	block: don't hold q->sysfs_lock in elevator_init_mq
	blk-mq: don't hold q->sysfs_lock in blk_mq_map_swqueue
	squashfs: add more sanity checks in id lookup
	squashfs: add more sanity checks in inode lookup
	squashfs: add more sanity checks in xattr id lookup
	regulator: core: enable power when setting up constraints
	regulator: core: Clean enabling always-on regulators + their supplies
	regulator: Fix lockdep warning resolving supplies
	Linux 4.19.176

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I33c221717e4e5c3213a7a21a648933a013bb2753
2021-02-13 14:25:08 +01:00
Steven Rostedt (VMware)
a19749a5fb fgraph: Initialize tracing_graph_pause at task creation
commit 7e0a9220467dbcfdc5bc62825724f3e52e50ab31 upstream.

On some archs, the idle task can call into cpu_suspend(). The cpu_suspend()
will disable or pause function graph tracing, as there's some paths in
bringing down the CPU that can have issues with its return address being
modified. The task_struct structure has a "tracing_graph_pause" atomic
counter, that when set to something other than zero, the function graph
tracer will not modify the return address.

The problem is that the tracing_graph_pause counter is initialized when the
function graph tracer is enabled. This can corrupt the counter for the idle
task if it is suspended in these architectures.

   CPU 1				CPU 2
   -----				-----
  do_idle()
    cpu_suspend()
      pause_graph_tracing()
          task_struct->tracing_graph_pause++ (0 -> 1)

				start_graph_tracing()
				  for_each_online_cpu(cpu) {
				    ftrace_graph_init_idle_task(cpu)
				      task-struct->tracing_graph_pause = 0 (1 -> 0)

      unpause_graph_tracing()
          task_struct->tracing_graph_pause-- (0 -> -1)

The above should have gone from 1 to zero, and enabled function graph
tracing again. But instead, it is set to -1, which keeps it disabled.

There's no reason that the field tracing_graph_pause on the task_struct can
not be initialized at boot up.

Cc: stable@vger.kernel.org
Fixes: 380c4b1411 ("tracing/function-graph-tracer: append the tracing_graph_flag")
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=211339
Reported-by: pierre.gondois@arm.com
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-13 13:51:13 +01:00
Masami Hiramatsu
960434acef tracing/kprobe: Fix to support kretprobe events on unloaded modules
commit 97c753e62e6c31a404183898d950d8c08d752dbd upstream.

Fix kprobe_on_func_entry() returns error code instead of false so that
register_kretprobe() can return an appropriate error code.

append_trace_kprobe() expects the kprobe registration returns -ENOENT
when the target symbol is not found, and it checks whether the target
module is unloaded or not. If the target module doesn't exist, it
defers to probe the target symbol until the module is loaded.

However, since register_kretprobe() returns -EINVAL instead of -ENOENT
in that case, it always fail on putting the kretprobe event on unloaded
modules. e.g.

Kprobe event:
/sys/kernel/debug/tracing # echo p xfs:xfs_end_io >> kprobe_events
[   16.515574] trace_kprobe: This probe might be able to register after target module is loaded. Continue.

Kretprobe event: (p -> r)
/sys/kernel/debug/tracing # echo r xfs:xfs_end_io >> kprobe_events
sh: write error: Invalid argument
/sys/kernel/debug/tracing # cat error_log
[   41.122514] trace_kprobe: error: Failed to register probe event
  Command: r xfs:xfs_end_io
             ^

To fix this bug, change kprobe_on_func_entry() to detect symbol lookup
failure and return -ENOENT in that case. Otherwise it returns -EINVAL
or 0 (succeeded, given address is on the entry).

Link: https://lkml.kernel.org/r/161176187132.1067016.8118042342894378981.stgit@devnote2

Cc: stable@vger.kernel.org
Fixes: 59158ec4aef7 ("tracing/kprobes: Check the probe on unloaded module correctly")
Reported-by: Jianlin Lv <Jianlin.Lv@arm.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-13 13:51:13 +01:00
Maciej Żenczykowski
4812ec5093 BACKPORT: bpf: add bpf_ktime_get_boot_ns()
On a device like a cellphone which is constantly suspending
and resuming CLOCK_MONOTONIC is not particularly useful for
keeping track of or reacting to external network events.
Instead you want to use CLOCK_BOOTTIME.

Hence add bpf_ktime_get_boot_ns() as a mirror of bpf_ktime_get_ns()
based around CLOCK_BOOTTIME instead of CLOCK_MONOTONIC.

Signed-off-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
(cherry picked from commit 71d19214776e61b33da48f7c1b46e522c7f78221)
Change-Id: Ifd62c410dcc5112fd1a473a7e1f70231ca514bc0
2021-02-11 18:18:10 -08:00
Greg Kroah-Hartman
1a02ec69a6 Merge 4.19.172 into android-4.19-stable
Changes in 4.19.172
	gpio: mvebu: fix pwm .get_state period calculation
	Revert "mm/slub: fix a memory leak in sysfs_slab_add()"
	futex: Move futex exit handling into futex code
	futex: Replace PF_EXITPIDONE with a state
	exit/exec: Seperate mm_release()
	futex: Split futex_mm_release() for exit/exec
	futex: Set task::futex_state to DEAD right after handling futex exit
	futex: Mark the begin of futex exit explicitly
	futex: Sanitize exit state handling
	futex: Provide state handling for exec() as well
	futex: Add mutex around futex exit
	futex: Provide distinct return value when owner is exiting
	futex: Prevent exit livelock
	futex: Ensure the correct return value from futex_lock_pi()
	futex: Replace pointless printk in fixup_owner()
	futex: Provide and use pi_state_update_owner()
	rtmutex: Remove unused argument from rt_mutex_proxy_unlock()
	futex: Use pi_state_update_owner() in put_pi_state()
	futex: Simplify fixup_pi_state_owner()
	futex: Handle faults correctly for PI futexes
	HID: wacom: Correct NULL dereference on AES pen proximity
	tracing: Fix race in trace_open and buffer resize call
	tools: Factor HOSTCC, HOSTLD, HOSTAR definitions
	dm integrity: conditionally disable "recalculate" feature
	writeback: Drop I_DIRTY_TIME_EXPIRE
	fs: fix lazytime expiration handling in __writeback_single_inode()
	Linux 4.19.172

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I9b5391e9e955a105ab9c144fa6258dcbea234211
2021-02-01 12:59:33 +01:00
Gaurav Kohli
acfa7ad7b7 tracing: Fix race in trace_open and buffer resize call
commit bbeb97464eefc65f506084fd9f18f21653e01137 upstream.

Below race can come, if trace_open and resize of
cpu buffer is running parallely on different cpus
CPUX                                CPUY
				    ring_buffer_resize
				    atomic_read(&buffer->resize_disabled)
tracing_open
tracing_reset_online_cpus
ring_buffer_reset_cpu
rb_reset_cpu
				    rb_update_pages
				    remove/insert pages
resetting pointer

This race can cause data abort or some times infinte loop in
rb_remove_pages and rb_insert_pages while checking pages
for sanity.

Take buffer lock to fix this.

Link: https://lkml.kernel.org/r/1601976833-24377-1-git-send-email-gkohli@codeaurora.org

Cc: stable@vger.kernel.org
Fixes: 83f40318da ("ring-buffer: Make removal of ring buffer pages atomic")
Reported-by: Denis Efremov <efremov@linux.com>
Signed-off-by: Gaurav Kohli <gkohli@codeaurora.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-30 13:32:13 +01:00
bo.ye
4f099f5a37 [ALPS05525109] [Do NOT Sync]Merge branch android-4.19-stable into alps-trunk-s0.basic
[Detail]
	Target: a175946a5a

MTK-Commit-Id: 2765eae88b32b52fa0e8d892ec7b1b897550f4a1

Feature: Others
Change-Id: Ia70d9ce11c361253362a469134bd0642b7f7dee6
CR-Id: ALPS05525109
Signed-off-by: Breeze Li <Breeze.Li@mediatek.com>
2021-01-29 03:17:04 +08:00
Steven Rostedt (VMware)
cf954d51bf [ALPS05388536] UPSTREAM: tracing: Fix trace_find_next_entry() accounting
The temp buffer size variable for trace_find_next_entry() was incorrectly
being updated when the size did not change. The temp buffer size should only
be updated when it is reallocated.

This is mostly an issue when used with ftrace_dump(). Thats because
ftrace_dump() can not allocate a new buffer, and instead uses a temporary
buffer with a fix size. But the variable that keeps track of that size is
incorrectly updated with each call, and it could fall into the path that
would try to reallocate the buffer and produce a warning.

 ------------[ cut here ]------------
 WARNING: CPU: 1 PID: 1601 at kernel/trace/trace.c:3548
trace_find_next_entry+0xd0/0xe0
 Modules linked in [..]
 CPU: 1 PID: 1601 Comm: bash Not tainted 5.9.0-rc5-test+ #521
 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03
07/14/2016
 RIP: 0010:trace_find_next_entry+0xd0/0xe0
 Code: 40 21 00 00 4c 89 e1 31 d2 4c 89 ee 48 89 df e8 c6 9e ff ff 89 ab 54
21 00 00 5b 5d 41 5c 41 5d c3 48 63 d5 eb bf 31 c0 eb f0 <0f> 0b 48 63 d5 eb
b4 66 0f 1f 84 00 00 00 00 00 53 48 8d 8f 60 21
 RSP: 0018:ffff95a4f2e8bd70 EFLAGS: 00010046
 RAX: ffffffff96679fc0 RBX: ffffffff97910de0 RCX: ffffffff96679fc0
 RDX: ffff95a4f2e8bd98 RSI: ffff95a4ee321098 RDI: ffffffff97913000
 RBP: 0000000000000018 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000001 R11: 0000000000000046 R12: ffff95a4f2e8bd98
 R13: 0000000000000000 R14: ffff95a4ee321098 R15: 00000000009aa301
 FS:  00007f8565484740(0000) GS:ffff95a55aa40000(0000)
knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 000055876bd43d90 CR3: 00000000b76e6003 CR4: 00000000001706e0
 Call Trace:
  trace_print_lat_context+0x58/0x2d0
  ? cpumask_next+0x16/0x20
  print_trace_line+0x1a4/0x4f0
  ftrace_dump.cold+0xad/0x12c
  __handle_sysrq.cold+0x51/0x126
  write_sysrq_trigger+0x3f/0x4a
  proc_reg_write+0x53/0x80
  vfs_write+0xca/0x210
  ksys_write+0x70/0xf0
  do_syscall_64+0x33/0x40
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 RIP: 0033:0x7f8565579487
 Code: 64 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa
64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff
77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
 RSP: 002b:00007ffd40707948 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f8565579487
 RDX: 0000000000000002 RSI: 000055876bd74de0 RDI: 0000000000000001
 RBP: 000055876bd74de0 R08: 000000000000000a R09: 0000000000000001
 R10: 000055876bdec280 R11: 0000000000000246 R12: 0000000000000002
 R13: 00007f856564a500 R14: 0000000000000002 R15: 00007f856564a700
 irq event stamp: 109958
 ---[ end trace 7aab5b7e51484b00 ]---

Not only fix the updating of the temp buffer, but also do not free the temp
buffer before a new buffer is allocated (theres no reason to not continue
to use the current temp buffer if an allocation fails).

MTK-Commit-Id: dec7aab57aed84161d93b7da447234e7e366a16b

Change-Id: I450814315eb033d4c06938e274e95c10293c1666
Cc: stable@vger.kernel.org
Fixes: 8e99cf91b99bb ("tracing: Do not allocate buffer in trace_find_next_entry() in atomic")
Reported-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Andress Kuo <andress.kuo@mediatek.com>
CR-Id: ALPS05388536
Feature: System Performance
Signed-off-by: Andress Kuo <andress.kuo@mediatek.com>
2021-01-29 02:38:47 +08:00
Eiichi Tsukata
1f23697ca9 [ALPS05369794] UPSTREAM: tracing: Fix out-of-range read in trace_sta
Puts range check before dereferencing the pointer.

Reproducer:

  # echo stacktrace > trace_options
  # echo 1 > events/enable
  # cat trace > /dev/null

KASAN report:

  ==================================================================
  BUG: KASAN: use-after-free in trace_stack_print+0x26b/0x2c0
  Read of size 8 at addr ffff888069d20000 by task cat/1953

  CPU: 0 PID: 1953 Comm: cat Not tainted 5.2.0-rc3+ #5
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-2.fc30 04/01/2014
  Call Trace:
   dump_stack+0x8a/0xce
   print_address_description+0x60/0x224
   ? trace_stack_print+0x26b/0x2c0
   ? trace_stack_print+0x26b/0x2c0
   __kasan_report.cold+0x1a/0x3e
   ? trace_stack_print+0x26b/0x2c0
   kasan_report+0xe/0x20
   trace_stack_print+0x26b/0x2c0
   print_trace_line+0x6ea/0x14d0
   ? tracing_buffers_read+0x700/0x700
   ? trace_find_next_entry_inc+0x158/0x1d0
   s_show+0xea/0x310
   seq_read+0xaa7/0x10e0
   ? seq_escape+0x230/0x230
   __vfs_read+0x7c/0x100
   vfs_read+0x16c/0x3a0
   ksys_read+0x121/0x240
   ? kernel_write+0x110/0x110
   ? perf_trace_sys_enter+0x8a0/0x8a0
   ? syscall_slow_exit_work+0xa9/0x410
   do_syscall_64+0xb7/0x390
   ? prepare_exit_to_usermode+0x165/0x200
   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  RIP: 0033:0x7f867681f910
  Code: b6 fe ff ff 48 8d 3d 0f be 08 00 48 83 ec 08 e8 06 db 01 00 66 0f 1f 44 00 00
  83 3d f9 2d 2c 00 00 75 10 b8 00 00 00 00 04
  RSP: 002b:00007ffdabf23488 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
  RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f867681f910
  RDX: 0000000000020000 RSI: 00007f8676cde000 RDI: 0000000000000003
  RBP: 00007f8676cde000 R08: ffffffffffffffff R09: 0000000000000000
  R10: 0000000000000871 R11: 0000000000000246 R12: 00007f8676cde000
  R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000000ec0

  Allocated by task 1214:
   save_stack+0x1b/0x80
   __kasan_kmalloc.constprop.0+0xc2/0xd0
   kmem_cache_alloc+0xaf/0x1a0
   getname_flags+0xd2/0x5b0
   do_sys_open+0x277/0x5a0
   do_syscall_64+0xb7/0x390
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

  Freed by task 1214:
   save_stack+0x1b/0x80
   __kasan_slab_free+0x12c/0x170
   kmem_cache_free+0x8a/0x1c0
   putname+0xe1/0x120
   do_sys_open+0x2c5/0x5a0
   do_syscall_64+0xb7/0x390
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

  The buggy address belongs to the object at ffff888069d20000
   which belongs to the cache names_cache of size 4096
  The buggy address is located 0 bytes inside of
   4096-byte region [ffff888069d20000, ffff888069d21000)
  The buggy address belongs to the page:
  page:ffffea0001a74800 refcount:1 mapcount:0 mapping:ffff88806ccd1380 index:0x0
  compound_mapcount: 0
  flags: 0x100000000010200(slab|head)
  raw: 0100000000010200 dead000000000100 dead000000000200 ffff88806ccd1380
  raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000
  page dumped because: kasan: bad access detected

  Memory state around the buggy address:
   ffff888069d1ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
   ffff888069d1ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  >ffff888069d20000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                     ^
   ffff888069d20080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
   ffff888069d20100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ==================================================================

Link: http://lkml.kernel.org/r/20190610040016.5598-1-devel@etsukata.com

Fixes: 4285f2fcef80 ("tracing: Remove the ULONG_MAX stack trace hackery")
Signed-off-by: Eiichi Tsukata <devel@etsukata.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

MTK-Commit-Id: 9d8890fbb0ac9899b04c3bbdb11d7a6c718a7e34

Signed-off-by: Andress Kuo <andress.kuo@mediatek.com>
Change-Id: Ib40dbfa6ada971312715c5e06f365930acf24d89
CR-Id: ALPS05369794
Feature: System Performance
2021-01-29 02:37:11 +08:00
Steven Rostedt (VMware)
aa21ca9b3a [ALPS05341379] tracing: Use trace array instead of current_tracer
tracing: Move pipe reference to trace array instead  of current_tracer

If a process has the trace_pipe open on a trace_array, the current tracer
for that trace array should not be changed. This was original enforced
by a global lock, but when instances were introduced, it was moved to the
current_trace. But this structure is shared by all instances, and a
trace_pipe is for a single instance. Theres no reason that a process
that has trace_pipe open on one instance should prevent another instance
from changing its current tracer. Move the reference counter to the
trace_array instead.

This is marked as "Fixes" but is more of a clean up than a true fix.
Backport if you want, but its not critical.

Fixes: cf6ab6d914 ("tracing: Add ref count to tracer for when they
are being read by pipe")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

MTK-Commit-Id: 2914bfd99798b2393f5347e8f7751d598695c84f

Change-Id: I81b1ab9454b1775e38267fd5a335acb793e4a199
CR-Id: ALPS05341379
Feature: System Performance
Signed-off-by: Andress Kuo <andress.kuo@mediatek.com>
2021-01-29 02:34:56 +08:00
Steven Rostedt (VMware)
47f7e00ebd [ALPS05269912] tracing: Save off entry when peeking at next entry
In order to have the iterator read the buffer even when its still
updating, it requires that the ring buffer iterator saves each event
in a separate location outside the ring buffer such that its use is
immutable.

Theres one use case that saves off the event returned from the
ring buffer interator and calls it again to look at the next event,
before going back to use the first event. As the ring buffer iterator
will only have a single copy, this use case will no longer be supported.

Instead, have the one use case create its own buffer to store the first
event when looking at the next event. This way, when looking at the
first event again, it wont be corrupted by the second read.

Link: http://lkml.kernel.org/r/20200317213415.722539921@goodmis.org

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

MTK-Commit-Id: 8c89b4015cc17df812443f4deccb8013de16adf1

Change-Id: Iafef6685da8e5167d2923fb4b80893a947a0143c
CR-Id: ALPS05269912
Feature: System Performance
Signed-off-by: Andress Kuo <andress.kuo@mediatek.com>
2021-01-29 02:20:43 +08:00