Messages in this thread Patch in this message | | | Date | Fri, 13 Mar 2009 18:09:41 -0700 | From | Greg KH <> | Subject | [patch 004/114] sparc64: Fix DAX handling via userspace access from kernel. |
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2.6.28-stable review patch. If anyone has any objections, please let us know.
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From: David S. Miller <davem@davemloft.net>
[ Upstream commit fcd26f7ae2ea5889134e8b3d60a42ce8b993c95f ]
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 <dgilmore@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- arch/sparc64/kernel/traps.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-)
--- a/arch/sparc64/kernel/traps.c +++ b/arch/sparc64/kernel/traps.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) */ @@ -313,6 +313,21 @@ void sun4v_data_access_exception(struct 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<UNKNOWN>\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);
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