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Message-Id: <1239279723.11859.18.camel@ht.satnam>
Date: Thu, 09 Apr 2009 17:52:03 +0530
From: Jaswinder Singh Rajput <jaswinder@...nel.org>
To: mingo@...hat.com, hpa@...or.com, h-shimamoto@...jp.nec.com,
linux-kernel@...r.kernel.org, roland@...hat.com,
tglx@...utronix.de, mingo@...e.hu
Cc: linux-tip-commits@...r.kernel.org
Subject: Re: [tip:x86/signal] x86: signal: check signal stack overflow
properly
Hiroshi-san,
I am getting few sparse warnings from your commited lines.
If possible, please run sparse before sending patch.
On Fri, 2009-03-20 at 18:03 +0000, Hiroshi Shimamoto wrote:
> Commit-ID: 14fc9fbc700dc95b4f46ebd588169324fe6deff8
> Gitweb: http://git.kernel.org/tip/14fc9fbc700dc95b4f46ebd588169324fe6deff8
> Author: Hiroshi Shimamoto <h-shimamoto@...jp.nec.com>
> AuthorDate: Thu, 19 Mar 2009 10:56:29 -0700
> Committer: Ingo Molnar <mingo@...e.hu>
> CommitDate: Fri, 20 Mar 2009 19:01:31 +0100
>
> x86: signal: check signal stack overflow properly
>
> Impact: cleanup
>
> Check alternate signal stack overflow with proper stack pointer.
> The stack pointer of the next signal frame is different if that
> task has i387 state.
>
> On x86_64, redzone would be included.
>
> No need to check SA_ONSTACK if we're already using alternate signal stack.
>
> Signed-off-by: Hiroshi Shimamoto <h-shimamoto@...jp.nec.com>
> Cc: Roland McGrath <roland@...hat.com>
> LKML-Reference: <49C2874D.3080002@...jp.nec.com>
> Signed-off-by: Ingo Molnar <mingo@...e.hu>
>
>
> ---
> arch/x86/kernel/signal.c | 48 +++++++++++++++++++++++++--------------------
> 1 files changed, 27 insertions(+), 21 deletions(-)
>
> diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
> index d2cc642..dfcc74a 100644
> --- a/arch/x86/kernel/signal.c
> +++ b/arch/x86/kernel/signal.c
> @@ -244,12 +240,22 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
> sp = round_down(sp, 64);
> #endif /* CONFIG_X86_64 */
> *fpstate = (void __user *)sp;
> -
> - if (save_i387_xstate(*fpstate) < 0)
> - return (void __user *)-1L;
> }
>
> - return (void __user *)align_sigframe(sp - frame_size);
> + sp = align_sigframe(sp - frame_size);
> +
> + /*
> + * If we are on the alternate signal stack and would overflow it, don't.
> + * Return an always-bogus address instead so we will die with SIGSEGV.
> + */
> + if (onsigstack && !likely(on_sig_stack(sp)))
> + return (void __user *)-1L;
arch/x86/kernel/signal.c:251:11: warning: cast adds address space to expression (<asn:1>)
> +
> + /* save i387 state */
> + if (used_math() && save_i387_xstate(*fpstate) < 0)
> + return (void __user *)-1L;
arch/x86/kernel/signal.c:255:11: warning: cast adds address space to expression (<asn:1>)
> +
> + return (void __user *)sp;
> }
>
> #ifdef CONFIG_X86_32
4a612048 arch/x86/kernel/signal_32.c (Hiroshi Shimamoto 2008-11-11 19:09:29 -0800 326) err |= __put_user(*((u64 *)&retcode), (u64 *)frame->retcode);
arch/x86/kernel/signal.c:326:9: warning: cast removes address space of expression
arch/x86/kernel/signal.c:326:9: warning: incorrect type in argument 1 (different address spaces)
arch/x86/kernel/signal.c:326:9: expected void const volatile [noderef] <asn:1>*<noident>
arch/x86/kernel/signal.c:326:9: got unsigned long long [usertype] *<noident>
arch/x86/kernel/signal.c:326:9: warning: cast removes address space of expression
arch/x86/kernel/signal.c:326:9: warning: cast removes address space of expression
arch/x86/kernel/signal.c:326:9: warning: cast removes address space of expression
arch/x86/kernel/signal.c:326:9: warning: cast adds address space to expression (<asn:1>)
arch/x86/kernel/signal.c:326:9: warning: cast removes address space of expression
arch/x86/kernel/signal.c:326:9: warning: cast removes address space of expression
arch/x86/kernel/signal.c:326:9: warning: cast adds address space to expression (<asn:1>)
arch/x86/kernel/signal.c:326:9: warning: cast removes address space of expression
arch/x86/kernel/signal.c:326:9: warning: cast removes address space of expression
arch/x86/kernel/signal.c:326:9: warning: cast adds address space to expression (<asn:1>)
arch/x86/kernel/signal.c:326:9: warning: cast removes address space of expression
arch/x86/kernel/signal.c:326:9: warning: cast removes address space of expression
arch/x86/kernel/signal.c:326:9: warning: cast removes address space of expression
98e3d45e arch/x86/kernel/signal.c (Hiroshi Shimamoto 2009-01-23 15:50:10 -0800 359) put_user_try {
98e3d45e arch/x86/kernel/signal.c (Hiroshi Shimamoto 2009-01-23 15:50:10 -0800 360) put_user_ex(sig, &frame->sig);
98e3d45e arch/x86/kernel/signal.c (Hiroshi Shimamoto 2009-01-23 15:50:10 -0800 361) put_user_ex(&frame->info, &frame->pinfo);
arch/x86/kernel/signal.c:361:3: warning: cast removes address space of expression
arch/x86/kernel/signal.c:361:3: warning: cast removes address space of expression
arch/x86/kernel/signal.c:361:3: warning: cast removes address space of expression
arch/x86/kernel/signal.c:361:3: warning: cast removes address space of expression
98e3d45e arch/x86/kernel/signal.c (Hiroshi Shimamoto 2009-01-23 15:50:10 -0800 362) put_user_ex(&frame->uc, &frame->puc);
arch/x86/kernel/signal.c:362:3: warning: cast removes address space of expression
arch/x86/kernel/signal.c:362:3: warning: cast removes address space of expression
arch/x86/kernel/signal.c:362:3: warning: cast removes address space of expression
arch/x86/kernel/signal.c:362:3: warning: cast removes address space of expression
98e3d45e arch/x86/kernel/signal.c (Hiroshi Shimamoto 2009-01-23 15:50:10 -0800 363) err |= copy_siginfo_to_user(&frame->info, info);
98e3d45e arch/x86/kernel/signal.c (Hiroshi Shimamoto 2009-01-23 15:50:10 -0800 364)
98e3d45e arch/x86/kernel/signal.c (Hiroshi Shimamoto 2009-01-23 15:50:10 -0800 379) /* Set up to return from userspace. */
98e3d45e arch/x86/kernel/signal.c (Hiroshi Shimamoto 2009-01-23 15:50:10 -0800 380) restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_si
arch/x86/kernel/signal.c:380:12: warning: incorrect type in assignment (different address spaces)
arch/x86/kernel/signal.c:380:12: expected void [noderef] <asn:1>*restorer
arch/x86/kernel/signal.c:380:12: got void *<noident>
98e3d45e arch/x86/kernel/signal.c (Hiroshi Shimamoto 2009-01-23 15:50:10 -0800 381) if (ka->sa.sa_flags & SA_RESTORER)
98e3d45e arch/x86/kernel/signal.c (Hiroshi Shimamoto 2009-01-23 15:50:10 -0800 382) restorer = ka->sa.sa_restorer;
98e3d45e arch/x86/kernel/signal.c (Hiroshi Shimamoto 2009-01-23 15:50:10 -0800 383) put_user_ex(restorer, &frame->pretcode);
arch/x86/kernel/signal.c:383:3: warning: cast removes address space of expression
arch/x86/kernel/signal.c:383:3: warning: cast removes address space of expression
arch/x86/kernel/signal.c:383:3: warning: cast removes address space of expression
arch/x86/kernel/signal.c:383:3: warning: cast removes address space of expression
98e3d45e arch/x86/kernel/signal.c (Hiroshi Shimamoto 2009-01-23 15:50:10 -0800 392) put_user_ex(*((u64 *)&rt_retcode), (u64 *)frame->retcode)
arch/x86/kernel/signal.c:392:3: warning: cast removes address space of expression
arch/x86/kernel/signal.c:392:3: warning: incorrect type in argument 1 (different address spaces)
arch/x86/kernel/signal.c:392:3: expected void const volatile [noderef] <asn:1>*<noident>
arch/x86/kernel/signal.c:392:3: got unsigned long long [usertype] *<noident>
arch/x86/kernel/signal.c:392:3: warning: cast removes address space of expression
arch/x86/kernel/signal.c:392:3: warning: cast removes address space of expression
arch/x86/kernel/signal.c:392:3: warning: cast removes address space of expression
arch/x86/kernel/signal.c:392:3: warning: cast adds address space to expression (<asn:1>)
arch/x86/kernel/signal.c:392:3: warning: cast removes address space of expression
arch/x86/kernel/signal.c:392:3: warning: cast removes address space of expression
arch/x86/kernel/signal.c:392:3: warning: cast adds address space to expression (<asn:1>)
arch/x86/kernel/signal.c:392:3: warning: cast removes address space of expression
arch/x86/kernel/signal.c:392:3: warning: cast removes address space of expression
arch/x86/kernel/signal.c:392:3: warning: cast adds address space to expression (<asn:1>)
arch/x86/kernel/signal.c:392:3: warning: cast removes address space of expression
arch/x86/kernel/signal.c:392:3: warning: cast removes address space of expression
arch/x86/kernel/signal.c:392:3: warning: cast removes address space of expression
--
JSR
--
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