From a1f9a89c90b4ac143c5b6054c2a157572b272cd2 Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Wed, 22 Apr 2009 20:33:40 +0200 Subject: [PATCH] ide-cd: fix kernel crash on hppa regression With 2.6.30-rc2 I face a kernel crash on the 32bit hppa architecture due to ide-cd when udev creates the device nodes at startup: Kernel Fault: Code=26 regs=8ed34c40 (Addr=00000024) IASQ: 00000000 00000000 IAOQ: 1034b5ac 1034b5b0 IIR: 4ab30048 ISR: 00000000 IOR: 00000024 CPU: 0 CR30: 8ed34000 CR31: ffff55ff ORIG_R28: 00000000 IAOQ[0]: ide_complete_rq+0x2c/0x70 IAOQ[1]: ide_complete_rq+0x30/0x70 RP(r2): cdrom_newpc_intr+0x178/0x46c Backtrace: [<1035c608>] cdrom_newpc_intr+0x178/0x46c [<1034c494>] ide_intr+0x1b0/0x214 [<1016d284>] handle_IRQ_event+0x70/0x150 [<1016d4b0>] __do_IRQ+0x14c/0x1cc [<102f7864>] superio_interrupt+0x88/0xbc [<1016d284>] handle_IRQ_event+0x70/0x150 [<1016d4b0>] __do_IRQ+0x14c/0x1cc [<10112efc>] do_cpu_irq_mask+0x9c/0xd0 [<10116068>] intr_return+0x0/0x4 This crash seems to happen due to an uninitialized variable "rc". The compiler even warns about that: CC drivers/ide/ide-cd.o /mnt/sda4/home/cvs/parisc/git-kernel/linus-linux-2.6/drivers/ide/ide-cd.c: In function `cdrom_newpc_intr': /mnt/sda4/home/cvs/parisc/git-kernel/linus-linux-2.6/drivers/ide/ide-cd.c:612: warning: `rc' might be used uninitialized in this function After applying the trivial patch below, which just initializes the variable to zero, the kernel doesn't crash any longer: Starting the hotplug events dispatcher: udevd. Synthesizing the initial hotplug events... hda: command error: status=0x51 { DriveReady SeekComplete Error } hda: command error: error=0x54 <3>{ AbortedCommand LastFailedSense=0x05 } ide: failed opcode was: unknown done. Signed-off-by: Helge Deller Acked-by: Borislav Petkov Cc: Linus Cc: Kyle McMartin Cc: "Rafael J. Wysocki" Signed-off-by: Bartlomiej Zolnierkiewicz --- drivers/ide/ide-cd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c index 3aec19d1fdfc..3d4e09969763 100644 --- a/drivers/ide/ide-cd.c +++ b/drivers/ide/ide-cd.c @@ -609,7 +609,7 @@ static ide_startstop_t cdrom_newpc_intr(ide_drive_t *drive) struct request *rq = hwif->rq; ide_expiry_t *expiry = NULL; int dma_error = 0, dma, thislen, uptodate = 0; - int write = (rq_data_dir(rq) == WRITE) ? 1 : 0, rc, nsectors; + int write = (rq_data_dir(rq) == WRITE) ? 1 : 0, rc = 0, nsectors; int sense = blk_sense_request(rq); unsigned int timeout; u16 len; -- 2.30.2