On Mon, 29 Mar 2010 17:34:11 +0200 (CEST) Julia Lawall <julia@xxxxxxx> wrote: > From: Julia Lawall <julia@xxxxxxx> > > Add local_irq_restore after the labels that can be reached after a > local_irq_save. > > A simplified version of the semantic patch that finds this problem is as > follows: (http://coccinelle.lip6.fr/) > > // <smpl> > @r exists@ > expression E1; > identifier f; > @@ > > f (...) { <+... > * local_irq_save (E1,...); > ... when != E1 > * return ...; > ...+> } > // </smpl> > > Signed-off-by: Julia Lawall <julia@xxxxxxx> > > --- > drivers/char/amiserial.c | 1 + > 1 files changed, 1 insertions(+), 0 deletions(-) > > diff --git a/drivers/char/amiserial.c b/drivers/char/amiserial.c > index 6c32fbf..2131ecb 100644 > --- a/drivers/char/amiserial.c > +++ b/drivers/char/amiserial.c > @@ -2056,6 +2056,7 @@ fail_free_irq: > free_irq(IRQ_AMIGA_TBE, state); > fail_unregister: > tty_unregister_driver(serial_driver); > + local_irq_restore(flags); > fail_release_mem_region: > release_mem_region(CUSTOM_PHYSADDR+0x30, 4); > fail_put_tty_driver: We shouldn't be calling tty_unregister_driver() with local interrupts disabled - it does mutex_lock() (at least), which will emit a might_sleep() warning (at least). I don't expect there was any need to disable irq's across the request_irq() calls (?), hence: From: Julia Lawall <julia@xxxxxxx> rs_init() is failing to restore interrupts on two error paths, and is incorrectly calling tty_unregister_driver() with local interrupts disabled. Fix these things by disabling interrupts later, after the reauest_irq() calls. A simplified version of the semantic patch that finds this problem is as follows: (http://coccinelle.lip6.fr/) // <smpl> @r exists@ expression E1; identifier f; @@ f (...) { <+... * local_irq_save (E1,...); ... when != E1 * return ...; ...+> } // </smpl> [akpm@xxxxxxxxxxxxxxxxxxxx: reimplement the fix] Signed-off-by: Julia Lawall <julia@xxxxxxx> Cc: Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxxxxxx> Cc: Greg KH <greg@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/char/amiserial.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff -puN drivers/char/amiserial.c~drivers-char-amiserialc-add-missing-local_irq_restore drivers/char/amiserial.c --- a/drivers/char/amiserial.c~drivers-char-amiserialc-add-missing-local_irq_restore +++ a/drivers/char/amiserial.c @@ -2021,8 +2021,6 @@ static int __init rs_init(void) state->baud_base = amiga_colorclock; state->xmit_fifo_size = 1; - local_irq_save(flags); - /* set ISRs, and then disable the rx interrupts */ error = request_irq(IRQ_AMIGA_TBE, ser_tx_int, 0, "serial TX", state); if (error) @@ -2033,6 +2031,8 @@ static int __init rs_init(void) if (error) goto fail_free_irq; + local_irq_save(flags); + /* turn off Rx and Tx interrupts */ custom.intena = IF_RBF | IF_TBE; mb(); _ -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
