From: John Ogness <john.ogness@linutronix.de>
To: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
Thomas Gleixner <tglx@linutronix.de>,
linux-kernel@vger.kernel.org,
Michael Ellerman <mpe@ellerman.id.au>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Jason Wessel <jason.wessel@windriver.com>,
Daniel Thompson <daniel.thompson@linaro.org>,
Douglas Anderson <dianders@chromium.org>,
Jordan Niethe <jniethe5@gmail.com>,
Alistair Popple <alistair@popple.id.au>,
Ravi Bangoria <ravi.bangoria@linux.ibm.com>,
Nicholas Piggin <npiggin@gmail.com>,
Madhavan Srinivasan <maddy@linux.ibm.com>,
Mike Rapoport <rppt@kernel.org>,
Kees Cook <keescook@chromium.org>,
Pavel Tatashin <pasha.tatashin@soleen.com>,
Oleg Nesterov <oleg@redhat.com>, Wei Li <liwei391@huawei.com>,
Davidlohr Bueso <dave@stgolabs.net>,
linuxppc-dev@lists.ozlabs.org,
kgdb-bugreport@lists.sourceforge.net
Subject: [PATCH next v4 11/15] printk: kmsg_dumper: remove @active field
Date: Wed, 3 Mar 2021 11:15:24 +0100 [thread overview]
Message-ID: <20210303101528.29901-12-john.ogness@linutronix.de> (raw)
In-Reply-To: <20210303101528.29901-1-john.ogness@linutronix.de>
All 6 kmsg_dumpers do not benefit from the @active flag:
(provide their own synchronization)
- arch/powerpc/kernel/nvram_64.c
- arch/um/kernel/kmsg_dump.c
- drivers/mtd/mtdoops.c
- fs/pstore/platform.c
(only dump on KMSG_DUMP_PANIC, which does not require
synchronization)
- arch/powerpc/platforms/powernv/opal-kmsg.c
- drivers/hv/vmbus_drv.c
The other 2 kmsg_dump users also do not rely on @active:
(hard-code @active to always be true)
- arch/powerpc/xmon/xmon.c
- kernel/debug/kdb/kdb_main.c
Therefore, @active can be removed.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
---
arch/powerpc/xmon/xmon.c | 2 +-
include/linux/kmsg_dump.h | 2 --
kernel/debug/kdb/kdb_main.c | 2 +-
kernel/printk/printk.c | 10 +---------
4 files changed, 3 insertions(+), 13 deletions(-)
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 3fe37495f63d..80ed3e1becf9 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -3001,7 +3001,7 @@ print_address(unsigned long addr)
static void
dump_log_buf(void)
{
- struct kmsg_dumper dumper = { .active = 1 };
+ struct kmsg_dumper dumper;
unsigned char buf[128];
size_t len;
diff --git a/include/linux/kmsg_dump.h b/include/linux/kmsg_dump.h
index 070c994ff19f..84eaa2090efa 100644
--- a/include/linux/kmsg_dump.h
+++ b/include/linux/kmsg_dump.h
@@ -36,7 +36,6 @@ enum kmsg_dump_reason {
* through the record iterator
* @max_reason: filter for highest reason number that should be dumped
* @registered: Flag that specifies if this is already registered
- * @active: Flag that specifies if this is currently dumping
* @cur_seq: Points to the oldest message to dump
* @next_seq: Points after the newest message to dump
*/
@@ -44,7 +43,6 @@ struct kmsg_dumper {
struct list_head list;
void (*dump)(struct kmsg_dumper *dumper, enum kmsg_dump_reason reason);
enum kmsg_dump_reason max_reason;
- bool active;
bool registered;
/* private state of the kmsg iterator */
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 930ac1b25ec7..315169d5e119 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -2101,7 +2101,7 @@ static int kdb_dmesg(int argc, const char **argv)
int adjust = 0;
int n = 0;
int skip = 0;
- struct kmsg_dumper dumper = { .active = 1 };
+ struct kmsg_dumper dumper;
size_t len;
char buf[201];
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index e794a08de00f..ce4cc64ba7c9 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -3408,8 +3408,6 @@ void kmsg_dump(enum kmsg_dump_reason reason)
continue;
/* initialize iterator with data about the stored records */
- dumper->active = true;
-
logbuf_lock_irqsave(flags);
dumper->cur_seq = latched_seq_read_nolock(&clear_seq);
dumper->next_seq = prb_next_seq(prb);
@@ -3417,9 +3415,6 @@ void kmsg_dump(enum kmsg_dump_reason reason)
/* invoke dumper which will iterate over records */
dumper->dump(dumper, reason);
-
- /* reset iterator */
- dumper->active = false;
}
rcu_read_unlock();
}
@@ -3454,9 +3449,6 @@ bool kmsg_dump_get_line_nolock(struct kmsg_dumper *dumper, bool syslog,
prb_rec_init_rd(&r, &info, line, size);
- if (!dumper->active)
- goto out;
-
/* Read text or count text lines? */
if (line) {
if (!prb_read_valid(prb, dumper->cur_seq, &r))
@@ -3542,7 +3534,7 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
bool ret = false;
bool time = printk_time;
- if (!dumper->active || !buf || !size)
+ if (!buf || !size)
goto out;
logbuf_lock_irqsave(flags);
--
2.20.1
next prev parent reply other threads:[~2021-03-03 14:55 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-03 10:15 [PATCH next v4 00/15] printk: remove logbuf_lock John Ogness
2021-03-03 10:15 ` [PATCH next v4 01/15] um: synchronize kmsg_dumper John Ogness
2021-03-03 10:15 ` [PATCH next v4 02/15] mtd: mtdoops: " John Ogness
2021-03-11 9:50 ` Miquel Raynal
2021-03-03 10:15 ` [PATCH next v4 03/15] printk: limit second loop of syslog_print_all John Ogness
2021-03-03 10:15 ` [PATCH next v4 04/15] printk: kmsg_dump: remove unused fields John Ogness
2021-03-03 10:15 ` [PATCH next v4 05/15] printk: refactor kmsg_dump_get_buffer() John Ogness
2021-03-03 10:15 ` [PATCH next v4 06/15] printk: consolidate kmsg_dump_get_buffer/syslog_print_all code John Ogness
2021-03-03 10:15 ` [PATCH next v4 07/15] printk: introduce CONSOLE_LOG_MAX John Ogness
2021-03-03 13:35 ` Petr Mladek
2021-03-03 10:15 ` [PATCH next v4 08/15] printk: use seqcount_latch for clear_seq John Ogness
2021-03-03 10:15 ` [PATCH next v4 09/15] printk: use atomic64_t for devkmsg_user.seq John Ogness
2021-03-03 10:15 ` [PATCH next v4 10/15] printk: add syslog_lock John Ogness
2021-03-03 10:15 ` John Ogness [this message]
2021-03-03 10:15 ` [PATCH next v4 12/15] printk: introduce a kmsg_dump iterator John Ogness
2021-03-03 13:48 ` Petr Mladek
2021-03-03 10:15 ` [PATCH next v4 13/15] printk: remove logbuf_lock John Ogness
2021-03-03 10:15 ` [PATCH next v4 14/15] printk: kmsg_dump: remove _nolock() variants John Ogness
2021-03-03 10:15 ` [PATCH next v4 15/15] printk: console: remove unnecessary safe buffer usage John Ogness
2021-03-03 13:18 ` lkml delivery: was: Re: [PATCH next v4 00/15] printk: remove logbuf_lock Petr Mladek
2021-03-03 14:34 ` Steven Rostedt
2021-03-03 15:34 ` Petr Mladek
2021-03-08 15:09 ` Petr Mladek
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