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um: kmsg_dumper: use srcu console list iterator 

Rather than using the console_lock to guarantee safe console list
traversal, use srcu console list iteration.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-14-john.ogness@linutronix.de
This commit is contained in:
John Ogness 2022-11-16 17:27:25 +01:06 committed by Petr Mladek
parent 100bdef2c1
commit 12335446e0
1 changed files with 5 additions and 8 deletions
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13
arch/um/kernel/kmsg_dump.c
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@ -16,29 +16,26 @@ static void kmsg_dumper_stdout(struct kmsg_dumper *dumper,
struct console *con; struct console *con;
unsigned long flags; unsigned long flags;
size_t len = 0; size_t len = 0;
int cookie;
/* /*
* If no consoles are available to output crash information, dump * If no consoles are available to output crash information, dump
* the kmsg buffer to stdout. * the kmsg buffer to stdout.
*/ */
if (!console_trylock()) cookie = console_srcu_read_lock();
return; for_each_console_srcu(con) {
for_each_console(con) {
/* /*
* The ttynull console and disabled consoles are ignored * The ttynull console and disabled consoles are ignored
* since they cannot output. All other consoles are * since they cannot output. All other consoles are
* expected to output the crash information. * expected to output the crash information.
*/ */
if (strcmp(con->name, "ttynull") != 0 && if (strcmp(con->name, "ttynull") != 0 &&
(con->flags & CON_ENABLED)) { (console_srcu_read_flags(con) & CON_ENABLED)) {
break; break;
} }
} }
console_srcu_read_unlock(cookie);
console_unlock();
if (con) if (con)
return; return;