From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: 2.6.26-rc: SPARC: Sun Ultra 10 can not boot Date: Thu, 07 Aug 2008 23:01:39 -0700 (PDT) Message-ID: <20080807.230139.220174417.davem@davemloft.net> References: <20080707.040126.178187777.davem@davemloft.net> <18546.5247.797478.66373@harpo.it.uu.se> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: sparclinux-owner@vger.kernel.org List-ID: Content-Type: Text/Plain; charset="us-ascii" To: a.beregalov@gmail.com Cc: mikpe@it.uu.se, kernel-testers@vger.kernel.org, sparclinux@vger.kernel.org, linux-kernel@vger.kernel.org From: "Alexander Beregalov" Date: Mon, 7 Jul 2008 19:59:04 +0400 > I have turned off LOCKDEP and it boots properly. > 2.6.26-rc9-00005-g1b40a89 > > Mikael's config also does not contain LOCKDEP. I have finally reproduced the problem locally and figured out the bug. Please try this patch: sparc64: Fix end-of-stack checking in save_stack_trace(). Bug reported by Alexander Beregalov. Before we dereference the stack frame or try to peek at the pt_regs magic value, make sure the entire object is within the kernel stack bounds. Signed-off-by: David S. Miller diff --git a/arch/sparc64/kernel/stacktrace.c b/arch/sparc64/kernel/stacktrace.c index c73ce3f..c5576e8 100644 --- a/arch/sparc64/kernel/stacktrace.c +++ b/arch/sparc64/kernel/stacktrace.c @@ -25,13 +25,15 @@ void save_stack_trace(struct stack_trace *trace) /* Bogus frame pointer? */ if (fp < (thread_base + sizeof(struct thread_info)) || - fp >= (thread_base + THREAD_SIZE)) + fp > (thread_base + THREAD_SIZE - sizeof(struct sparc_stackf))) break; sf = (struct sparc_stackf *) fp; regs = (struct pt_regs *) (sf + 1); - if ((regs->magic & ~0x1ff) == PT_REGS_MAGIC) { + if (((unsigned long)regs <= + (thread_base + THREAD_SIZE - sizeof(*regs))) && + (regs->magic & ~0x1ff) == PT_REGS_MAGIC) { if (!(regs->tstate & TSTATE_PRIV)) break; pc = regs->tpc;