From: David S. Miller Date: Tue, 20 Jan 2009 06:44:04 +0000 (-0800) Subject: sparc64: Fix DAX handling via userspace access from kernel. X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=fcd26f7ae2ea5889134e8b3d60a42ce8b993c95f;p=openwrt%2Fstaging%2Fblogic.git sparc64: Fix DAX handling via userspace access from kernel. If we do a userspace access from kernel mode, and get a data access exception, we need to check the exception table just like a normal fault does. The spitfire DAX handler was doing this, but such logic was missing from the sun4v DAX code. Reported-by: Dennis Gilmore Signed-off-by: David S. Miller --- diff --git a/arch/sparc/kernel/traps_64.c b/arch/sparc/kernel/traps_64.c index c2d153d46586..d809c4ebb48f 100644 --- a/arch/sparc/kernel/traps_64.c +++ b/arch/sparc/kernel/traps_64.c @@ -1,6 +1,6 @@ /* arch/sparc64/kernel/traps.c * - * Copyright (C) 1995,1997,2008 David S. Miller (davem@davemloft.net) + * Copyright (C) 1995,1997,2008,2009 David S. Miller (davem@davemloft.net) * Copyright (C) 1997,1999,2000 Jakub Jelinek (jakub@redhat.com) */ @@ -314,6 +314,21 @@ void sun4v_data_access_exception(struct pt_regs *regs, unsigned long addr, unsig return; if (regs->tstate & TSTATE_PRIV) { + /* Test if this comes from uaccess places. */ + const struct exception_table_entry *entry; + + entry = search_exception_tables(regs->tpc); + if (entry) { + /* Ouch, somebody is trying VM hole tricks on us... */ +#ifdef DEBUG_EXCEPTIONS + printk("Exception: PC<%016lx> faddr\n", regs->tpc); + printk("EX_TABLE: insn<%016lx> fixup<%016lx>\n", + regs->tpc, entry->fixup); +#endif + regs->tpc = entry->fixup; + regs->tnpc = regs->tpc + 4; + return; + } printk("sun4v_data_access_exception: ADDR[%016lx] " "CTX[%04x] TYPE[%04x], going.\n", addr, ctx, type);