Re: Kernel unaligned access at TPC[10101f18] btrfs_csum_final+0x38/0x60

David Miller
2010-02-05T20:01:51Z

From: Christian Kujau <lists@nerdbynature.de>
Date: Fri, 5 Feb 2010 10:36:52 -0800 (PST)

> When writing to a newly created btrfs (vanilla 2.6.33-rc6, sparc64) the
> following messages are printed:
>
> [28617.650231] Kernel unaligned access at TPC[10101f18] btrfs_csum_final+0x38/0x60 [btrfs]
> [28617.745783] Kernel unaligned access at TPC[10101f18] btrfs_csum_final+0x38/0x60 [btrfs]
> [28654.589492] Kernel unaligned access at TPC[10101f18] btrfs_csum_final+0x38/0x60 [btrfs]
> [28654.685036] Kernel unaligned access at TPC[10101f18] btrfs_csum_final+0x38/0x60 [btrfs]
> [28689.595394] Kernel unaligned access at TPC[10101f18] btrfs_csum_final+0x38/0x60 [btrfs]

Can you rerun your test with the following patch applied?

It will obtain more information for the btrfs developers.

Thanks!

diff --git a/arch/sparc/kernel/unaligned_64.c b/arch/sparc/kernel/unaligned_64.c
index 378ca82..cbde2ea 100644
--- a/arch/sparc/kernel/unaligned_64.c
+++ b/arch/sparc/kernel/unaligned_64.c
@@ -283,6 +283,9 @@ static void log_unaligned(struct pt_regs *regs)
count++;
printk("Kernel unaligned access at TPC[%lx] %pS\n",
regs->tpc, (void *) regs->tpc);
+ printk("Caller [%lx:%pS]\n",
+ regs->u_regs[UREG_RETPC],
+ (void *) regs->u_regs[UREG_RETPC]);
}
}