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ad0b65efd1
Fixes an obvious bug in cdc-acm by avoiding a recursive lock on acm_start_wb()'s error path. Should apply towards 2.6.27 stable and 2.6.28. ============================================= [ INFO: possible recursive locking detected ] 2.6.27-2-pae #109 --------------------------------------------- python/31449 is trying to acquire lock: (&acm->write_lock){++..}, at: [<f89a0348>] acm_start_wb+0x5c/0x7b [cdc_acm] but task is already holding lock: (&acm->write_lock){++..}, at: [<f89a04fb>] acm_tty_write+0xe1/0x167 [cdc_acm] other info that might help us debug this: 2 locks held by python/31449: #0: (&tty->atomic_write_lock){--..}, at: [<c0260fae>] tty_write_lock+0x14/0x3b #1: (&acm->write_lock){++..}, at: [<f89a04fb>] acm_tty_write+0xe1/0x167 [cdc_acm] stack backtrace: Pid: 31449, comm: python Not tainted 2.6.27-2-pae #109 [<c030f42f>] ? printk+0xf/0x18 [<c0149f33>] __lock_acquire+0xc7b/0x1316 [<c014a63e>] lock_acquire+0x70/0x97 [<f89a0348>] ? acm_start_wb+0x5c/0x7b [cdc_acm] [<c0312109>] _spin_lock_irqsave+0x37/0x47 [<f89a0348>] ? acm_start_wb+0x5c/0x7b [cdc_acm] [<f89a0348>] acm_start_wb+0x5c/0x7b [cdc_acm] [<f89a055d>] acm_tty_write+0x143/0x167 [cdc_acm] [<c0262a98>] write_chan+0x1cd/0x297 [<c012527e>] ? default_wake_function+0x0/0xd [<c026111e>] tty_write+0x149/0x1b9 [<c02628cb>] ? write_chan+0x0/0x297 [<c01912c5>] ? rw_verify_area+0x76/0x98 [<c0260fd5>] ? tty_write+0x0/0x1b9 [<c01919ba>] vfs_write+0x8c/0x136 [<c0191afd>] sys_write+0x3b/0x60 [<c0103beb>] sysenter_do_call+0x12/0x3f ======================= Signed-off-by: Brandon Philips <bphilips@suse.de> Cc: Oliver Neukum <oliver@neukum.org> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
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| .. | ||
| cdc-acm.c | ||
| cdc-acm.h | ||
| cdc-wdm.c | ||
| Kconfig | ||
| Makefile | ||
| usblp.c | ||
| usbtmc.c | ||