From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org,
Daniel Bristot de Oliveira <bristot@kernel.org>,
"Steven Rostedt (Google)" <rostedt@goodmis.org>
Subject: [PATCH 5.4 58/64] tracing/histogram: Fix sorting on old "cpu" value
Date: Mon, 7 Mar 2022 10:19:31 +0100 [thread overview]
Message-ID: <20220307091640.796258993@linuxfoundation.org> (raw)
In-Reply-To: <20220307091639.136830784@linuxfoundation.org>
From: Steven Rostedt (Google) <rostedt@goodmis.org>
commit 1d1898f65616c4601208963c3376c1d828cbf2c7 upstream.
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: 1e3bac71c505 ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
kernel/trace/trace_events_hist.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -2891,9 +2891,9 @@ parse_field(struct hist_trigger_data *hi
/*
* For backward compatibility, if field_name
* was "cpu", then we treat this the same as
- * common_cpu.
+ * common_cpu. This also works for "CPU".
*/
- if (strcmp(field_name, "cpu") == 0) {
+ if (field && field->filter_type == FILTER_CPU) {
*flags |= HIST_FIELD_FL_CPU;
} else {
hist_err(tr, HIST_ERR_FIELD_NOT_FOUND,
@@ -5247,7 +5247,7 @@ static int create_tracing_map_fields(str
if (hist_field->flags & HIST_FIELD_FL_STACKTRACE)
cmp_fn = tracing_map_cmp_none;
- else if (!field)
+ else if (!field || hist_field->flags & HIST_FIELD_FL_CPU)
cmp_fn = tracing_map_cmp_num(hist_field->size,
hist_field->is_signed);
else if (is_string_field(field))
next prev parent reply other threads:[~2022-03-07 9:41 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-07 9:18 [PATCH 5.4 00/64] 5.4.183-rc1 review Greg Kroah-Hartman
2022-03-07 9:18 ` [PATCH 5.4 01/64] mac80211_hwsim: report NOACK frames in tx_status Greg Kroah-Hartman
2022-03-07 9:18 ` [PATCH 5.4 02/64] mac80211_hwsim: initialize ieee80211_tx_info at hw_scan_work Greg Kroah-Hartman
2022-03-07 9:18 ` [PATCH 5.4 03/64] i2c: bcm2835: Avoid clock stretching timeouts Greg Kroah-Hartman
2022-03-07 9:18 ` [PATCH 5.4 04/64] ASoC: rt5668: do not block workqueue if card is unbound Greg Kroah-Hartman
2022-03-07 9:18 ` [PATCH 5.4 05/64] ASoC: rt5682: " Greg Kroah-Hartman
2022-03-07 9:18 ` [PATCH 5.4 06/64] Input: clear BTN_RIGHT/MIDDLE on buttonpads Greg Kroah-Hartman
2022-03-07 9:18 ` [PATCH 5.4 07/64] cifs: fix double free race when mount fails in cifs_get_root() Greg Kroah-Hartman
2022-03-07 9:18 ` [PATCH 5.4 08/64] dmaengine: shdma: Fix runtime PM imbalance on error Greg Kroah-Hartman
2022-03-07 9:18 ` [PATCH 5.4 09/64] i2c: cadence: allow COMPILE_TEST Greg Kroah-Hartman
2022-03-07 9:18 ` [PATCH 5.4 10/64] i2c: qup: " Greg Kroah-Hartman
2022-03-07 9:18 ` [PATCH 5.4 11/64] net: usb: cdc_mbim: avoid altsetting toggling for Telit FN990 Greg Kroah-Hartman
2022-03-07 9:18 ` [PATCH 5.4 12/64] usb: gadget: dont release an existing dev->buf Greg Kroah-Hartman
2022-03-07 9:18 ` [PATCH 5.4 13/64] usb: gadget: clear related members when goto fail Greg Kroah-Hartman
2022-03-07 9:18 ` [PATCH 5.4 14/64] ata: pata_hpt37x: fix PCI clock detection Greg Kroah-Hartman
2022-03-07 9:18 ` [PATCH 5.4 15/64] ALSA: intel_hdmi: Fix reference to PCM buffer address Greg Kroah-Hartman
2022-03-07 9:18 ` [PATCH 5.4 16/64] ASoC: ops: Shift tested values in snd_soc_put_volsw() by +min Greg Kroah-Hartman
2022-03-07 9:18 ` [PATCH 5.4 17/64] xfrm: fix MTU regression Greg Kroah-Hartman
2022-03-07 9:18 ` [PATCH 5.4 18/64] netfilter: fix use-after-free in __nf_register_net_hook() Greg Kroah-Hartman
2022-03-07 9:18 ` [PATCH 5.4 19/64] xfrm: fix the if_id check in changelink Greg Kroah-Hartman
2022-03-07 9:18 ` [PATCH 5.4 20/64] xfrm: enforce validity of offload input flags Greg Kroah-Hartman
2022-03-07 9:18 ` [PATCH 5.4 21/64] netfilter: nf_queue: dont assume sk is full socket Greg Kroah-Hartman
2022-03-07 9:18 ` [PATCH 5.4 22/64] netfilter: nf_queue: fix possible use-after-free Greg Kroah-Hartman
2022-03-07 9:18 ` [PATCH 5.4 23/64] batman-adv: Request iflink once in batadv-on-batadv check Greg Kroah-Hartman
2022-03-07 9:18 ` [PATCH 5.4 24/64] batman-adv: Request iflink once in batadv_get_real_netdevice Greg Kroah-Hartman
2022-03-07 9:18 ` [PATCH 5.4 25/64] batman-adv: Dont expect inter-netns unique iflink indices Greg Kroah-Hartman
2022-03-07 9:18 ` [PATCH 5.4 26/64] net: dcb: flush lingering app table entries for unregistered devices Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 27/64] net/smc: fix unexpected SMC_CLC_DECL_ERR_REGRMB error generated by client Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 28/64] net/smc: fix unexpected SMC_CLC_DECL_ERR_REGRMB error cause by server Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 29/64] block: Fix fsync always failed if once failed Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 30/64] xen/netfront: destroy queues before real_num_tx_queues is zeroed Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 31/64] sched/topology: Make sched_init_numa() use a set for the deduplicating sort Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 32/64] sched/topology: Fix sched_domain_topology_level alloc in sched_init_numa() Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 33/64] ia64: ensure proper NUMA distance and possible map initialization Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 34/64] mac80211: fix forwarded mesh frames AC & queue selection Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 35/64] net: stmmac: fix return value of __setup handler Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 36/64] iavf: Fix missing check for running netdev Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 37/64] net: sxgbe: fix return value of __setup handler Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 38/64] net: arcnet: com20020: Fix null-ptr-deref in com20020pci_probe() Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 39/64] ixgbe: xsk: change !netif_carrier_ok() handling in ixgbe_xmit_zc() Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 40/64] efivars: Respect "block" flag in efivar_entry_set_safe() Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 41/64] firmware: arm_scmi: Remove space in MODULE_ALIAS name Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 42/64] ASoC: cs4265: Fix the duplicated control name Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 43/64] can: gs_usb: change active_channelss type from atomic_t to u8 Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 44/64] arm64: dts: rockchip: Switch RK3399-Gru DP to SPDIF output Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 45/64] igc: igc_read_phy_reg_gpy: drop premature return Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 46/64] ARM: Fix kgdb breakpoint for Thumb2 Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 47/64] ARM: 9182/1: mmu: fix returns from early_param() and __setup() functions Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 48/64] igc: igc_write_phy_reg_gpy: drop premature return Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 49/64] ibmvnic: free reset-work-item when flushing Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 50/64] memfd: fix F_SEAL_WRITE after shmem huge page allocated Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 51/64] soc: fsl: qe: Check of ioremap return value Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 52/64] net: chelsio: cxgb3: check the return value of pci_find_capability() Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 53/64] nl80211: Handle nla_memdup failures in handle_nan_filter Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 54/64] Input: elan_i2c - move regulator_[en|dis]able() out of elan_[en|dis]able_power() Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 55/64] Input: elan_i2c - fix regulator enable count imbalance after suspend/resume Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 56/64] HID: add mapping for KEY_DICTATE Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 57/64] HID: add mapping for KEY_ALL_APPLICATIONS Greg Kroah-Hartman
2022-03-07 9:19 ` Greg Kroah-Hartman [this message]
2022-03-07 9:19 ` [PATCH 5.4 59/64] tracing: Fix return value of __setup handlers Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 60/64] btrfs: fix lost prealloc extents beyond eof after full fsync Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 61/64] btrfs: qgroup: fix deadlock between rescan worker and remove qgroup Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 62/64] btrfs: add missing run of delayed items after unlink during log replay Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 63/64] Revert "xfrm: xfrm_state_mtu should return at least 1280 for ipv6" Greg Kroah-Hartman
2022-03-07 9:19 ` [PATCH 5.4 64/64] net: dcb: disable softirqs in dcbnl_flush_dev() Greg Kroah-Hartman
2022-03-07 18:46 ` [PATCH 5.4 00/64] 5.4.183-rc1 review Florian Fainelli
2022-03-07 23:47 ` Shuah Khan
2022-03-08 0:53 ` Samuel Zou
2022-03-08 15:19 ` Naresh Kamboju
2022-03-08 15:46 ` Sudip Mukherjee
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