From: David S. Miller <davem@davemloft.net>
Date: Wed, 27 Feb 2008 01:30:02 +0000 (-0800)
Subject: [SPARC64]: Loosen checks in exception table handling.
X-Git-Tag: v2.6.25-rc4~149^2~1
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=622eaec613130e6ea78f2a5d5070e3278b21cd8f;p=linux-2.6

[SPARC64]: Loosen checks in exception table handling.

Some parts of the kernel now do things like do *_user() accesses while
set_fs(KERNEL_DS) that fault on purpose.

See, for example, the code added by changeset
a0c1e9073ef7428a14309cba010633a6cd6719ea ("futex: runtime enable pi
and robust functionality").

That trips up the ASI sanity checking we make in do_kernel_fault().

Just remove it for now.  Maybe we can add it back later with an added
conditional which looks at the current get_fs() value.

Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/arch/sparc64/mm/fault.c b/arch/sparc64/mm/fault.c
index e2027f27c0..9183633602 100644
--- a/arch/sparc64/mm/fault.c
+++ b/arch/sparc64/mm/fault.c
@@ -244,16 +244,8 @@ static void do_kernel_fault(struct pt_regs *regs, int si_code, int fault_code,
 	if (regs->tstate & TSTATE_PRIV) {
 		const struct exception_table_entry *entry;
 
-		if (asi == ASI_P && (insn & 0xc0800000) == 0xc0800000) {
-			if (insn & 0x2000)
-				asi = (regs->tstate >> 24);
-			else
-				asi = (insn >> 5);
-		}
-	
-		/* Look in asi.h: All _S asis have LS bit set */
-		if ((asi & 0x1) &&
-		    (entry = search_exception_tables(regs->tpc))) {
+		entry = search_exception_tables(regs->tpc);
+		if (entry) {
 			regs->tpc = entry->fixup;
 			regs->tnpc = regs->tpc + 4;
 			return;