From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>,
Heiko Carstens <hca@linux.ibm.com>,
Sasha Levin <sashal@kernel.org>,
linux-s390@vger.kernel.org
Subject: [PATCH AUTOSEL 5.14 44/47] s390/debug: keep debug data on resize
Date: Sun, 5 Sep 2021 21:19:48 -0400 [thread overview]
Message-ID: <20210906011951.928679-44-sashal@kernel.org> (raw)
In-Reply-To: <20210906011951.928679-1-sashal@kernel.org>
From: Peter Oberparleiter <oberpar@linux.ibm.com>
[ Upstream commit 1204777867e8486a88dbb4793fe256b31ea05eeb ]
Any previously recorded s390dbf debug data is reset when a debug area
is resized using the 'pages' sysfs attribute. This can make
live-debugging unnecessarily complex.
Fix this by copying existing debug data to the newly allocated debug
area when resizing.
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/s390/kernel/debug.c | 74 ++++++++++++++++++++++++++++------------
1 file changed, 53 insertions(+), 21 deletions(-)
diff --git a/arch/s390/kernel/debug.c b/arch/s390/kernel/debug.c
index 09b6c6402f9b..0dbe48f550ff 100644
--- a/arch/s390/kernel/debug.c
+++ b/arch/s390/kernel/debug.c
@@ -24,6 +24,7 @@
#include <linux/export.h>
#include <linux/init.h>
#include <linux/fs.h>
+#include <linux/minmax.h>
#include <linux/debugfs.h>
#include <asm/debug.h>
@@ -92,6 +93,8 @@ static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view,
char *out_buf, const char *in_buf);
static int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view,
char *out_buf, debug_sprintf_entry_t *curr_event);
+static void debug_areas_swap(debug_info_t *a, debug_info_t *b);
+static void debug_events_append(debug_info_t *dest, debug_info_t *src);
/* globals */
@@ -726,35 +729,28 @@ EXPORT_SYMBOL(debug_unregister);
*/
static int debug_set_size(debug_info_t *id, int nr_areas, int pages_per_area)
{
- debug_entry_t ***new_areas;
+ debug_info_t *new_id;
unsigned long flags;
- int rc = 0;
if (!id || (nr_areas <= 0) || (pages_per_area < 0))
return -EINVAL;
- if (pages_per_area > 0) {
- new_areas = debug_areas_alloc(pages_per_area, nr_areas);
- if (!new_areas) {
- pr_info("Allocating memory for %i pages failed\n",
- pages_per_area);
- rc = -ENOMEM;
- goto out;
- }
- } else {
- new_areas = NULL;
+
+ new_id = debug_info_alloc("", pages_per_area, nr_areas, id->buf_size,
+ id->level, ALL_AREAS);
+ if (!new_id) {
+ pr_info("Allocating memory for %i pages failed\n",
+ pages_per_area);
+ return -ENOMEM;
}
+
spin_lock_irqsave(&id->lock, flags);
- debug_areas_free(id);
- id->areas = new_areas;
- id->nr_areas = nr_areas;
- id->pages_per_area = pages_per_area;
- id->active_area = 0;
- memset(id->active_entries, 0, sizeof(int)*id->nr_areas);
- memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
+ debug_events_append(new_id, id);
+ debug_areas_swap(new_id, id);
+ debug_info_free(new_id);
spin_unlock_irqrestore(&id->lock, flags);
pr_info("%s: set new size (%i pages)\n", id->name, pages_per_area);
-out:
- return rc;
+
+ return 0;
}
/**
@@ -821,6 +817,42 @@ static inline debug_entry_t *get_active_entry(debug_info_t *id)
id->active_entries[id->active_area]);
}
+/* Swap debug areas of a and b. */
+static void debug_areas_swap(debug_info_t *a, debug_info_t *b)
+{
+ swap(a->nr_areas, b->nr_areas);
+ swap(a->pages_per_area, b->pages_per_area);
+ swap(a->areas, b->areas);
+ swap(a->active_area, b->active_area);
+ swap(a->active_pages, b->active_pages);
+ swap(a->active_entries, b->active_entries);
+}
+
+/* Append all debug events in active area from source to destination log. */
+static void debug_events_append(debug_info_t *dest, debug_info_t *src)
+{
+ debug_entry_t *from, *to, *last;
+
+ if (!src->areas || !dest->areas)
+ return;
+
+ /* Loop over all entries in src, starting with oldest. */
+ from = get_active_entry(src);
+ last = from;
+ do {
+ if (from->clock != 0LL) {
+ to = get_active_entry(dest);
+ memset(to, 0, dest->entry_size);
+ memcpy(to, from, min(src->entry_size,
+ dest->entry_size));
+ proceed_active_entry(dest);
+ }
+
+ proceed_active_entry(src);
+ from = get_active_entry(src);
+ } while (from != last);
+}
+
/*
* debug_finish_entry:
* - set timestamp, caller address, cpu number etc.
--
2.30.2
next prev parent reply other threads:[~2021-09-06 1:22 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-06 1:19 [PATCH AUTOSEL 5.14 01/47] locking/mutex: Fix HANDOFF condition Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 02/47] regmap: fix the offset of register error log Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 03/47] regulator: tps65910: Silence deferred probe error Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 04/47] crypto: mxs-dcp - Check for DMA mapping errors Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 05/47] sched/deadline: Fix reset_on_fork reporting of DL tasks Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 06/47] power: supply: axp288_fuel_gauge: Report register-address on readb / writeb errors Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 07/47] crypto: omap-sham - clear dma flags only after omap_sham_update_dma_stop() Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 08/47] sched/deadline: Fix missing clock update in migrate_task_rq_dl() Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 09/47] rcu/tree: Handle VM stoppage in stall detection Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 10/47] EDAC/mce_amd: Do not load edac_mce_amd module on guests Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 11/47] posix-cpu-timers: Force next expiration recalc after itimer reset Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 12/47] hrtimer: Avoid double reprogramming in __hrtimer_start_range_ns() Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 13/47] hrtimer: Ensure timerfd notification for HIGHRES=n Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 14/47] udf: Check LVID earlier Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 15/47] udf: Fix iocharset=utf8 mount option Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 16/47] isofs: joliet: " Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 17/47] bcache: add proper error unwinding in bcache_device_init Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 18/47] nbd: add the check to prevent overflow in __nbd_ioctl() Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 19/47] blk-throtl: optimize IOPS throttle for large IO scenarios Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 20/47] nvme-tcp: don't update queue count when failing to set io queues Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 21/47] nvme-rdma: " Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 22/47] nvmet: pass back cntlid on successful completion Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 23/47] power: supply: smb347-charger: Add missing pin control activation Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 24/47] power: supply: max17042_battery: fix typo in MAx17042_TOFF Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 25/47] s390/cio: add dev_busid sysfs entry for each subchannel Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 26/47] s390/zcrypt: fix wrong offset index for APKA master key valid state Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 27/47] libata: fix ata_host_start() Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 28/47] sched/topology: Skip updating masks for non-online nodes Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 29/47] crypto: omap - Fix inconsistent locking of device lists Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 30/47] crypto: qat - do not ignore errors from enable_vf2pf_comms() Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 31/47] crypto: qat - handle both source of interrupt in VF ISR Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 32/47] crypto: qat - fix reuse of completion variable Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 33/47] crypto: qat - fix naming for init/shutdown VF to PF notifications Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 34/47] crypto: qat - do not export adf_iov_putmsg() Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 35/47] crypto: hisilicon/sec - fix the abnormal exiting process Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 36/47] crypto: hisilicon/sec - modify the hardware endian configuration Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 37/47] crypto: tcrypt - Fix missing return value check Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 38/47] fcntl: fix potential deadlocks for &fown_struct.lock Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 39/47] fcntl: fix potential deadlock for &fasync_struct.fa_lock Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 40/47] udf_get_extendedattr() had no boundary checks Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 41/47] io-wq: remove GFP_ATOMIC allocation off schedule out path Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 42/47] s390/kasan: fix large PMD pages address alignment check Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 43/47] s390/pci: fix misleading rc in clp_set_pci_fn() Sasha Levin
2021-09-06 1:19 ` Sasha Levin [this message]
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 45/47] s390/debug: fix debug area life cycle Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 46/47] s390/ap: fix state machine hang after failure to enable irq Sasha Levin
2021-09-06 1:19 ` [PATCH AUTOSEL 5.14 47/47] s390/smp: enable DAT before CPU restart callback is called Sasha Levin
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