Messages in this thread Patch in this message | | | From | Thomas Gleixner <> | Subject | [patch RFC 07/29] printk: Convert console list walks for readers to list lock | Date | Sun, 11 Sep 2022 00:27:42 +0200 (CEST) |
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Facilities which expose console information to sysfs or procfs can use the new list protection to keep the list stable. No need to hold console lock.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- drivers/tty/tty_io.c | 6 +++--- fs/proc/consoles.c | 6 +++--- kernel/printk/printk.c | 8 ++++---- 3 files changed, 10 insertions(+), 10 deletions(-)
--- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -3535,8 +3535,8 @@ static ssize_t show_cons_active(struct d struct console *c; ssize_t count = 0; - console_lock(); - for_each_console(c) { + console_list_lock(); + for_each_registered_console(c) { if (!c->device) continue; if (!c->write) @@ -3560,7 +3560,7 @@ static ssize_t show_cons_active(struct d count += sprintf(buf + count, "%c", i ? ' ':'\n'); } - console_unlock(); + console_list_unlock(); return count; } --- a/fs/proc/consoles.c +++ b/fs/proc/consoles.c @@ -63,8 +63,8 @@ static void *c_start(struct seq_file *m, struct console *con; loff_t off = 0; - console_lock(); - for_each_console(con) + console_list_lock(); + for_each_registered_console(con) if (off++ == *pos) break; @@ -80,7 +80,7 @@ static void *c_next(struct seq_file *m, static void c_stop(struct seq_file *m, void *v) { - console_unlock(); + console_list_unlock(); } static const struct seq_operations consoles_op = { --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -2985,18 +2985,18 @@ void console_flush_on_panic(enum con_flu */ struct tty_driver *console_device(int *index) { - struct console *c; struct tty_driver *driver = NULL; + struct console *c; - console_lock(); - for_each_console(c) { + console_list_lock(); + for_each_registered_console(c) { if (!c->device) continue; driver = c->device(c, index); if (driver) break; } - console_unlock(); + console_list_unlock(); return driver; }
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