Gitweb:
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=4bf3631cdb012591667ab927fcd7719d92837833
Commit: 4bf3631cdb012591667ab927fcd7719d92837833
Parent: c5408b88ecb8b7127334a34c55d4e0174434f4ec
Author: Jiri Kosina <[EMAIL PROTECTED]>
AuthorDate: Mon Apr 23 14:41:21 2007 -0700
Committer: Linus Torvalds <[EMAIL PROTECTED]>
CommitDate: Tue Apr 24 08:23:09 2007 -0700
8250: fix possible deadlock between serial8250_handle_port() and
serial8250_interrupt()
Commit 40b36daa introduced possibility that serial8250_backup_timeout() ->
serial8250_handle_port() locks port.lock without disabling irqs, thus
allowing deadlock against interrupt handler (port.lock is acquired in
serial8250_interrupt()).
Spotted by lockdep.
Signed-off-by: Jiri Kosina <[EMAIL PROTECTED]>
Cc: Dave Jones <[EMAIL PROTECTED]>
Cc: Russell King <[EMAIL PROTECTED]>
Cc: Alex Williamson <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
Signed-off-by: Linus Torvalds <[EMAIL PROTECTED]>
---
drivers/serial/8250.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index c0c472a..90621c3 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -1334,8 +1334,9 @@ static inline void
serial8250_handle_port(struct uart_8250_port *up)
{
unsigned int status;
+ unsigned long flags;
- spin_lock(&up->port.lock);
+ spin_lock_irqsave(&up->port.lock, flags);
status = serial_inp(up, UART_LSR);
@@ -1347,7 +1348,7 @@ serial8250_handle_port(struct uart_8250_port *up)
if (status & UART_LSR_THRE)
transmit_chars(up);
- spin_unlock(&up->port.lock);
+ spin_unlock_irqrestore(&up->port.lock, flags);
}
/*
-
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