Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932169Ab1CILa6 (ORCPT ); Wed, 9 Mar 2011 06:30:58 -0500 Received: from smtp-out.google.com ([74.125.121.67]:33519 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753508Ab1CILa4 (ORCPT ); Wed, 9 Mar 2011 06:30:56 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=google.com; s=beta; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=mAb4tVM3QK2M1uplXiSAKQxRzvKAjBzQDnpsMrpc+RJ5hfabyBOQf+jBjvklk/646T p2bCIN33Zz0+lMwwxbjg== Date: Wed, 9 Mar 2011 03:25:50 -0800 From: Michel Lespinasse To: Thomas Gleixner Cc: Darren Hart , Ingo Molnar , Peter Zijlstra , Matt Turner , Russell King , David Howells , Tony Luck , Michal Simek , Ralf Baechle , "James E.J. Bottomley" , Benjamin Herrenschmidt , Martin Schwidefsky , Paul Mundt , "David S. Miller" , Chris Metcalf , Andrew Morton , Linus Torvalds , LKML Subject: Re: [PATCH] futex: cmpxchg_futex_value_locked API change Message-ID: <20110309112550.GA3050@google.com> References: <20110307021127.GB31188@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 43034 Lines: 1312 On Tue, Mar 08, 2011 at 09:17:11PM +0100, Thomas Gleixner wrote: > On Sun, 6 Mar 2011, Michel Lespinasse wrote: > > The cmpxchg_futex_value_locked API was funny in that it returned either > > the original, user-exposed futex value OR an error code such as -EFAULT. > > This was confusing at best, and could be a source of livelocks in places > > that retry the cmpxchg_futex_value_locked after trying to fix the issue > > by running fault_in_user_writeable(). > > > > This change makes the cmpxchg_futex_value_locked API more similar to the > > get_futex_value_locked one, returning an error code and updating the > > original value through a reference argument. > > Ack. > > > static inline int > > -futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval) > > +futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr, > > + int oldval, int newval) > > Can we please change the arguments to u32 while at it? The futex core > code uses u32 all over the place so those inlines should do the same. All right. Attaching updated version of the diff. I also fixed the s390 issue reported by Martin Schwidefsky. What's the proper path to check this in, could you send it towards the -next tree so it gets more testing ? --------------------------------------8<------------------------------- The cmpxchg_futex_value_locked API was funny in that it returned either the original, user-exposed futex value OR an error code such as -EFAULT. This was confusing at best, and could be a source of livelocks in places that retry the cmpxchg_futex_value_locked after trying to fix the issue by running fault_in_user_writeable(). This change makes the cmpxchg_futex_value_locked API more similar to the get_futex_value_locked one, returning an error code and updating the original value through a reference argument. Additionally, the futex pointer types have been changed to u32 * in both futex_atomic_cmpxchg_inatomic and futex_atomic_op_inuser internal APIs as suggested by Thomas Gleixner. Signed-off-by: Michel Lespinasse Acked-by: Chris Metcalf (for tile) Acked-by: Tony Luck (for ia64) Acked-by: Thomas Gleixner Tested-by: Michal Simek (for microblaze) --- arch/alpha/include/asm/futex.h | 29 ++++++++++++---------- arch/arm/include/asm/futex.h | 30 ++++++++++++---------- arch/frv/include/asm/futex.h | 5 ++- arch/frv/kernel/futex.c | 14 +++++----- arch/ia64/include/asm/futex.h | 15 +++++++---- arch/microblaze/include/asm/futex.h | 31 +++++++++++++---------- arch/mips/include/asm/futex.h | 39 ++++++++++++++++------------- arch/parisc/include/asm/futex.h | 24 +++++++++--------- arch/powerpc/include/asm/futex.h | 27 +++++++++++--------- arch/s390/include/asm/futex.h | 12 ++++---- arch/s390/include/asm/uaccess.h | 4 +- arch/s390/lib/uaccess.h | 8 +++--- arch/s390/lib/uaccess_pt.c | 17 +++++++----- arch/s390/lib/uaccess_std.c | 8 ++++-- arch/sh/include/asm/futex-irq.h | 24 +++++++++--------- arch/sh/include/asm/futex.h | 11 ++++---- arch/sparc/include/asm/futex_64.h | 20 +++++++++------ arch/tile/include/asm/futex.h | 27 ++++++++++---------- arch/x86/include/asm/futex.h | 22 +++++++++------- include/asm-generic/futex.h | 7 +++-- kernel/futex.c | 46 ++++++++++++---------------------- 21 files changed, 219 insertions(+), 201 deletions(-) diff --git a/arch/alpha/include/asm/futex.h b/arch/alpha/include/asm/futex.h index 945de22..e8a761a 100644 --- a/arch/alpha/include/asm/futex.h +++ b/arch/alpha/include/asm/futex.h @@ -29,7 +29,7 @@ : "r" (uaddr), "r"(oparg) \ : "memory") -static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr) +static inline int futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr) { int op = (encoded_op >> 28) & 7; int cmp = (encoded_op >> 24) & 15; @@ -39,7 +39,7 @@ static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr) if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) oparg = 1 << oparg; - if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; pagefault_disable(); @@ -81,21 +81,23 @@ static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr) } static inline int -futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval) +futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, + u32 oldval, u32 newval) { - int prev, cmp; + int ret = 0, cmp; + u32 prev; - if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; __asm__ __volatile__ ( __ASM_SMP_MB - "1: ldl_l %0,0(%2)\n" - " cmpeq %0,%3,%1\n" - " beq %1,3f\n" - " mov %4,%1\n" - "2: stl_c %1,0(%2)\n" - " beq %1,4f\n" + "1: ldl_l %1,0(%3)\n" + " cmpeq %1,%4,%2\n" + " beq %2,3f\n" + " mov %5,%2\n" + "2: stl_c %2,0(%3)\n" + " beq %2,4f\n" "3: .subsection 2\n" "4: br 1b\n" " .previous\n" @@ -105,11 +107,12 @@ futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval) " .long 2b-.\n" " lda $31,3b-2b(%0)\n" " .previous\n" - : "=&r"(prev), "=&r"(cmp) + : "+r"(ret), "=&r"(prev), "=&r"(cmp) : "r"(uaddr), "r"((long)oldval), "r"(newval) : "memory"); - return prev; + *uval = prev; + return ret; } #endif /* __KERNEL__ */ diff --git a/arch/arm/include/asm/futex.h b/arch/arm/include/asm/futex.h index b33fe70..0e29d8e 100644 --- a/arch/arm/include/asm/futex.h +++ b/arch/arm/include/asm/futex.h @@ -35,7 +35,7 @@ : "cc", "memory") static inline int -futex_atomic_op_inuser (int encoded_op, int __user *uaddr) +futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr) { int op = (encoded_op >> 28) & 7; int cmp = (encoded_op >> 24) & 15; @@ -46,7 +46,7 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr) if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) oparg = 1 << oparg; - if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; pagefault_disable(); /* implies preempt_disable() */ @@ -88,36 +88,38 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr) } static inline int -futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval) +futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, + u32 oldval, u32 newval) { - int val; + int ret = 0; + u32 val; - if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; - pagefault_disable(); /* implies preempt_disable() */ + /* Note that preemption is disabled by futex_atomic_cmpxchg_inatomic + * call sites. */ __asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n" - "1: " T(ldr) " %0, [%3]\n" - " teq %0, %1\n" + "1: " T(ldr) " %1, [%4]\n" + " teq %1, %2\n" " it eq @ explicit IT needed for the 2b label\n" - "2: " T(streq) " %2, [%3]\n" + "2: " T(streq) " %3, [%4]\n" "3:\n" " .pushsection __ex_table,\"a\"\n" " .align 3\n" " .long 1b, 4f, 2b, 4f\n" " .popsection\n" " .pushsection .fixup,\"ax\"\n" - "4: mov %0, %4\n" + "4: mov %0, %5\n" " b 3b\n" " .popsection" - : "=&r" (val) + : "+r" (ret), "=&r" (val) : "r" (oldval), "r" (newval), "r" (uaddr), "Ir" (-EFAULT) : "cc", "memory"); - pagefault_enable(); /* subsumes preempt_enable() */ - - return val; + *uval = val; + return ret; } #endif /* !SMP */ diff --git a/arch/frv/include/asm/futex.h b/arch/frv/include/asm/futex.h index 08b3d1d..4bea27f 100644 --- a/arch/frv/include/asm/futex.h +++ b/arch/frv/include/asm/futex.h @@ -7,10 +7,11 @@ #include #include -extern int futex_atomic_op_inuser(int encoded_op, int __user *uaddr); +extern int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr); static inline int -futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval) +futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, + u32 oldval, u32 newval) { return -ENOSYS; } diff --git a/arch/frv/kernel/futex.c b/arch/frv/kernel/futex.c index 14f64b0..d155ca9 100644 --- a/arch/frv/kernel/futex.c +++ b/arch/frv/kernel/futex.c @@ -18,7 +18,7 @@ * the various futex operations; MMU fault checking is ignored under no-MMU * conditions */ -static inline int atomic_futex_op_xchg_set(int oparg, int __user *uaddr, int *_oldval) +static inline int atomic_futex_op_xchg_set(int oparg, u32 __user *uaddr, int *_oldval) { int oldval, ret; @@ -50,7 +50,7 @@ static inline int atomic_futex_op_xchg_set(int oparg, int __user *uaddr, int *_o return ret; } -static inline int atomic_futex_op_xchg_add(int oparg, int __user *uaddr, int *_oldval) +static inline int atomic_futex_op_xchg_add(int oparg, u32 __user *uaddr, int *_oldval) { int oldval, ret; @@ -83,7 +83,7 @@ static inline int atomic_futex_op_xchg_add(int oparg, int __user *uaddr, int *_o return ret; } -static inline int atomic_futex_op_xchg_or(int oparg, int __user *uaddr, int *_oldval) +static inline int atomic_futex_op_xchg_or(int oparg, u32 __user *uaddr, int *_oldval) { int oldval, ret; @@ -116,7 +116,7 @@ static inline int atomic_futex_op_xchg_or(int oparg, int __user *uaddr, int *_ol return ret; } -static inline int atomic_futex_op_xchg_and(int oparg, int __user *uaddr, int *_oldval) +static inline int atomic_futex_op_xchg_and(int oparg, u32 __user *uaddr, int *_oldval) { int oldval, ret; @@ -149,7 +149,7 @@ static inline int atomic_futex_op_xchg_and(int oparg, int __user *uaddr, int *_o return ret; } -static inline int atomic_futex_op_xchg_xor(int oparg, int __user *uaddr, int *_oldval) +static inline int atomic_futex_op_xchg_xor(int oparg, u32 __user *uaddr, int *_oldval) { int oldval, ret; @@ -186,7 +186,7 @@ static inline int atomic_futex_op_xchg_xor(int oparg, int __user *uaddr, int *_o /* * do the futex operations */ -int futex_atomic_op_inuser(int encoded_op, int __user *uaddr) +int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr) { int op = (encoded_op >> 28) & 7; int cmp = (encoded_op >> 24) & 15; @@ -197,7 +197,7 @@ int futex_atomic_op_inuser(int encoded_op, int __user *uaddr) if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) oparg = 1 << oparg; - if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; pagefault_disable(); diff --git a/arch/ia64/include/asm/futex.h b/arch/ia64/include/asm/futex.h index c7f0f06..8428525 100644 --- a/arch/ia64/include/asm/futex.h +++ b/arch/ia64/include/asm/futex.h @@ -46,7 +46,7 @@ do { \ } while (0) static inline int -futex_atomic_op_inuser (int encoded_op, int __user *uaddr) +futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr) { int op = (encoded_op >> 28) & 7; int cmp = (encoded_op >> 24) & 15; @@ -56,7 +56,7 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr) if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) oparg = 1 << oparg; - if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int))) + if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; pagefault_disable(); @@ -100,23 +100,26 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr) } static inline int -futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval) +futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, + u32 oldval, u32 newval) { - if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; { - register unsigned long r8 __asm ("r8"); + register unsigned long r8 __asm ("r8") = 0; + unsigned long prev; __asm__ __volatile__( " mf;; \n" " mov ar.ccv=%3;; \n" "[1:] cmpxchg4.acq %0=[%1],%2,ar.ccv \n" " .xdata4 \"__ex_table\", 1b-., 2f-. \n" "[2:]" - : "=r" (r8) + : "=r" (prev) : "r" (uaddr), "r" (newval), "rO" ((long) (unsigned) oldval) : "memory"); + *uval = prev; return r8; } } diff --git a/arch/microblaze/include/asm/futex.h b/arch/microblaze/include/asm/futex.h index ad3fd61..b0526d2 100644 --- a/arch/microblaze/include/asm/futex.h +++ b/arch/microblaze/include/asm/futex.h @@ -29,7 +29,7 @@ }) static inline int -futex_atomic_op_inuser(int encoded_op, int __user *uaddr) +futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr) { int op = (encoded_op >> 28) & 7; int cmp = (encoded_op >> 24) & 15; @@ -39,7 +39,7 @@ futex_atomic_op_inuser(int encoded_op, int __user *uaddr) if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) oparg = 1 << oparg; - if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; pagefault_disable(); @@ -94,31 +94,34 @@ futex_atomic_op_inuser(int encoded_op, int __user *uaddr) } static inline int -futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval) +futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, + u32 oldval, u32 newval) { - int prev, cmp; + int ret = 0, cmp; + u32 prev; - if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; - __asm__ __volatile__ ("1: lwx %0, %2, r0; \ - cmp %1, %0, %3; \ - beqi %1, 3f; \ - 2: swx %4, %2, r0; \ - addic %1, r0, 0; \ - bnei %1, 1b; \ + __asm__ __volatile__ ("1: lwx %1, %3, r0; \ + cmp %2, %1, %4; \ + beqi %2, 3f; \ + 2: swx %5, %3, r0; \ + addic %2, r0, 0; \ + bnei %2, 1b; \ 3: \ .section .fixup,\"ax\"; \ 4: brid 3b; \ - addik %0, r0, %5; \ + addik %0, r0, %6; \ .previous; \ .section __ex_table,\"a\"; \ .word 1b,4b,2b,4b; \ .previous;" \ - : "=&r" (prev), "=&r"(cmp) \ + : "+r" (ret), "=&r" (prev), "=&r"(cmp) \ : "r" (uaddr), "r" (oldval), "r" (newval), "i" (-EFAULT)); - return prev; + *uval = prev; + return ret; } #endif /* __KERNEL__ */ diff --git a/arch/mips/include/asm/futex.h b/arch/mips/include/asm/futex.h index b9cce90..6ebf173 100644 --- a/arch/mips/include/asm/futex.h +++ b/arch/mips/include/asm/futex.h @@ -75,7 +75,7 @@ } static inline int -futex_atomic_op_inuser(int encoded_op, int __user *uaddr) +futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr) { int op = (encoded_op >> 28) & 7; int cmp = (encoded_op >> 24) & 15; @@ -85,7 +85,7 @@ futex_atomic_op_inuser(int encoded_op, int __user *uaddr) if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) oparg = 1 << oparg; - if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int))) + if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; pagefault_disable(); @@ -132,11 +132,13 @@ futex_atomic_op_inuser(int encoded_op, int __user *uaddr) } static inline int -futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval) +futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, + u32 oldval, u32 newval) { - int retval; + int ret = 0; + u32 val; - if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; if (cpu_has_llsc && R10000_LLSC_WAR) { @@ -145,25 +147,25 @@ futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval) " .set push \n" " .set noat \n" " .set mips3 \n" - "1: ll %0, %2 \n" - " bne %0, %z3, 3f \n" + "1: ll %1, %3 \n" + " bne %1, %z4, 3f \n" " .set mips0 \n" - " move $1, %z4 \n" + " move $1, %z5 \n" " .set mips3 \n" - "2: sc $1, %1 \n" + "2: sc $1, %2 \n" " beqzl $1, 1b \n" __WEAK_LLSC_MB "3: \n" " .set pop \n" " .section .fixup,\"ax\" \n" - "4: li %0, %5 \n" + "4: li %0, %6 \n" " j 3b \n" " .previous \n" " .section __ex_table,\"a\" \n" " "__UA_ADDR "\t1b, 4b \n" " "__UA_ADDR "\t2b, 4b \n" " .previous \n" - : "=&r" (retval), "=R" (*uaddr) + : "+r" (ret), "=&r" (val), "=R" (*uaddr) : "R" (*uaddr), "Jr" (oldval), "Jr" (newval), "i" (-EFAULT) : "memory"); } else if (cpu_has_llsc) { @@ -172,31 +174,32 @@ futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval) " .set push \n" " .set noat \n" " .set mips3 \n" - "1: ll %0, %2 \n" - " bne %0, %z3, 3f \n" + "1: ll %1, %3 \n" + " bne %1, %z4, 3f \n" " .set mips0 \n" - " move $1, %z4 \n" + " move $1, %z5 \n" " .set mips3 \n" - "2: sc $1, %1 \n" + "2: sc $1, %2 \n" " beqz $1, 1b \n" __WEAK_LLSC_MB "3: \n" " .set pop \n" " .section .fixup,\"ax\" \n" - "4: li %0, %5 \n" + "4: li %0, %6 \n" " j 3b \n" " .previous \n" " .section __ex_table,\"a\" \n" " "__UA_ADDR "\t1b, 4b \n" " "__UA_ADDR "\t2b, 4b \n" " .previous \n" - : "=&r" (retval), "=R" (*uaddr) + : "+r" (ret), "=&r" (val), "=R" (*uaddr) : "R" (*uaddr), "Jr" (oldval), "Jr" (newval), "i" (-EFAULT) : "memory"); } else return -ENOSYS; - return retval; + *uval = val; + return ret; } #endif diff --git a/arch/parisc/include/asm/futex.h b/arch/parisc/include/asm/futex.h index 0c705c3..67a33cc 100644 --- a/arch/parisc/include/asm/futex.h +++ b/arch/parisc/include/asm/futex.h @@ -8,7 +8,7 @@ #include static inline int -futex_atomic_op_inuser (int encoded_op, int __user *uaddr) +futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr) { int op = (encoded_op >> 28) & 7; int cmp = (encoded_op >> 24) & 15; @@ -18,7 +18,7 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr) if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) oparg = 1 << oparg; - if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int))) + if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; pagefault_disable(); @@ -51,10 +51,10 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr) /* Non-atomic version */ static inline int -futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval) +futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, + u32 oldval, u32 newval) { - int err = 0; - int uval; + u32 val; /* futex.c wants to do a cmpxchg_inatomic on kernel NULL, which is * our gateway page, and causes no end of trouble... @@ -62,15 +62,15 @@ futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval) if (segment_eq(KERNEL_DS, get_fs()) && !uaddr) return -EFAULT; - if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; - err = get_user(uval, uaddr); - if (err) return -EFAULT; - if (uval == oldval) - err = put_user(newval, uaddr); - if (err) return -EFAULT; - return uval; + if (get_user(val, uaddr)) + return -EFAULT; + if (val == oldval && put_user(newval, uaddr)) + return -EFAULT; + *uval = val; + return 0; } #endif /*__KERNEL__*/ diff --git a/arch/powerpc/include/asm/futex.h b/arch/powerpc/include/asm/futex.h index 7c589ef..c94e4a3 100644 --- a/arch/powerpc/include/asm/futex.h +++ b/arch/powerpc/include/asm/futex.h @@ -30,7 +30,7 @@ : "b" (uaddr), "i" (-EFAULT), "r" (oparg) \ : "cr0", "memory") -static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr) +static inline int futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr) { int op = (encoded_op >> 28) & 7; int cmp = (encoded_op >> 24) & 15; @@ -40,7 +40,7 @@ static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr) if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) oparg = 1 << oparg; - if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int))) + if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; pagefault_disable(); @@ -82,35 +82,38 @@ static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr) } static inline int -futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval) +futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, + u32 oldval, u32 newval) { - int prev; + int ret = 0; + u32 prev; - if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; __asm__ __volatile__ ( PPC_RELEASE_BARRIER -"1: lwarx %0,0,%2 # futex_atomic_cmpxchg_inatomic\n\ - cmpw 0,%0,%3\n\ +"1: lwarx %1,0,%3 # futex_atomic_cmpxchg_inatomic\n\ + cmpw 0,%1,%4\n\ bne- 3f\n" - PPC405_ERR77(0,%2) -"2: stwcx. %4,0,%2\n\ + PPC405_ERR77(0,%3) +"2: stwcx. %5,0,%3\n\ bne- 1b\n" PPC_ACQUIRE_BARRIER "3: .section .fixup,\"ax\"\n\ -4: li %0,%5\n\ +4: li %0,%6\n\ b 3b\n\ .previous\n\ .section __ex_table,\"a\"\n\ .align 3\n\ " PPC_LONG "1b,4b,2b,4b\n\ .previous" \ - : "=&r" (prev), "+m" (*uaddr) + : "+r" (ret), "=&r" (prev), "+m" (*uaddr) : "r" (uaddr), "r" (oldval), "r" (newval), "i" (-EFAULT) : "cc", "memory"); - return prev; + *uval = prev; + return ret; } #endif /* __KERNEL__ */ diff --git a/arch/s390/include/asm/futex.h b/arch/s390/include/asm/futex.h index 5c5d02d..81cf36b 100644 --- a/arch/s390/include/asm/futex.h +++ b/arch/s390/include/asm/futex.h @@ -7,7 +7,7 @@ #include #include -static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr) +static inline int futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr) { int op = (encoded_op >> 28) & 7; int cmp = (encoded_op >> 24) & 15; @@ -18,7 +18,7 @@ static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr) if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) oparg = 1 << oparg; - if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int))) + if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; pagefault_disable(); @@ -39,13 +39,13 @@ static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr) return ret; } -static inline int futex_atomic_cmpxchg_inatomic(int __user *uaddr, - int oldval, int newval) +static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, + u32 oldval, u32 newval) { - if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int))) + if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; - return uaccess.futex_atomic_cmpxchg(uaddr, oldval, newval); + return uaccess.futex_atomic_cmpxchg(uval, uaddr, oldval, newval); } #endif /* __KERNEL__ */ diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h index d6b1ed0..2d9ea11f 100644 --- a/arch/s390/include/asm/uaccess.h +++ b/arch/s390/include/asm/uaccess.h @@ -83,8 +83,8 @@ struct uaccess_ops { size_t (*clear_user)(size_t, void __user *); size_t (*strnlen_user)(size_t, const char __user *); size_t (*strncpy_from_user)(size_t, const char __user *, char *); - int (*futex_atomic_op)(int op, int __user *, int oparg, int *old); - int (*futex_atomic_cmpxchg)(int __user *, int old, int new); + int (*futex_atomic_op)(int op, u32 __user *, int oparg, int *old); + int (*futex_atomic_cmpxchg)(u32 *, u32 __user *, u32 old, u32 new); }; extern struct uaccess_ops uaccess; diff --git a/arch/s390/lib/uaccess.h b/arch/s390/lib/uaccess.h index 126011d..1d2536c 100644 --- a/arch/s390/lib/uaccess.h +++ b/arch/s390/lib/uaccess.h @@ -12,12 +12,12 @@ extern size_t copy_from_user_std(size_t, const void __user *, void *); extern size_t copy_to_user_std(size_t, void __user *, const void *); extern size_t strnlen_user_std(size_t, const char __user *); extern size_t strncpy_from_user_std(size_t, const char __user *, char *); -extern int futex_atomic_cmpxchg_std(int __user *, int, int); -extern int futex_atomic_op_std(int, int __user *, int, int *); +extern int futex_atomic_cmpxchg_std(u32 *, u32 __user *, u32, u32); +extern int futex_atomic_op_std(int, u32 __user *, int, int *); extern size_t copy_from_user_pt(size_t, const void __user *, void *); extern size_t copy_to_user_pt(size_t, void __user *, const void *); -extern int futex_atomic_op_pt(int, int __user *, int, int *); -extern int futex_atomic_cmpxchg_pt(int __user *, int, int); +extern int futex_atomic_op_pt(int, u32 __user *, int, int *); +extern int futex_atomic_cmpxchg_pt(u32 *, u32 __user *, u32, u32); #endif /* __ARCH_S390_LIB_UACCESS_H */ diff --git a/arch/s390/lib/uaccess_pt.c b/arch/s390/lib/uaccess_pt.c index 404f2de..afc716a 100644 --- a/arch/s390/lib/uaccess_pt.c +++ b/arch/s390/lib/uaccess_pt.c @@ -302,7 +302,7 @@ fault: : "0" (-EFAULT), "d" (oparg), "a" (uaddr), \ "m" (*uaddr) : "cc" ); -static int __futex_atomic_op_pt(int op, int __user *uaddr, int oparg, int *old) +static int __futex_atomic_op_pt(int op, u32 __user *uaddr, int oparg, int *old) { int oldval = 0, newval, ret; @@ -335,7 +335,7 @@ static int __futex_atomic_op_pt(int op, int __user *uaddr, int oparg, int *old) return ret; } -int futex_atomic_op_pt(int op, int __user *uaddr, int oparg, int *old) +int futex_atomic_op_pt(int op, u32 __user *uaddr, int oparg, int *old) { int ret; @@ -354,26 +354,29 @@ int futex_atomic_op_pt(int op, int __user *uaddr, int oparg, int *old) return ret; } -static int __futex_atomic_cmpxchg_pt(int __user *uaddr, int oldval, int newval) +static int __futex_atomic_cmpxchg_pt(u32 *uval, u32 __user *uaddr, + u32 oldval, u32 newval) { int ret; asm volatile("0: cs %1,%4,0(%5)\n" - "1: lr %0,%1\n" + "1: la %0,0\n" "2:\n" EX_TABLE(0b,2b) EX_TABLE(1b,2b) : "=d" (ret), "+d" (oldval), "=m" (*uaddr) : "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr) : "cc", "memory" ); + *uval = oldval; return ret; } -int futex_atomic_cmpxchg_pt(int __user *uaddr, int oldval, int newval) +int futex_atomic_cmpxchg_pt(int *uval, int __user *uaddr, + int oldval, int newval) { int ret; if (segment_eq(get_fs(), KERNEL_DS)) - return __futex_atomic_cmpxchg_pt(uaddr, oldval, newval); + return __futex_atomic_cmpxchg_pt(uval, uaddr, oldval, newval); spin_lock(¤t->mm->page_table_lock); uaddr = (int __user *) __dat_user_addr((unsigned long) uaddr); if (!uaddr) { @@ -382,7 +385,7 @@ int futex_atomic_cmpxchg_pt(int __user *uaddr, int oldval, int newval) } get_page(virt_to_page(uaddr)); spin_unlock(¤t->mm->page_table_lock); - ret = __futex_atomic_cmpxchg_pt(uaddr, oldval, newval); + ret = __futex_atomic_cmpxchg_pt(uval, uaddr, oldval, newval); put_page(virt_to_page(uaddr)); return ret; } diff --git a/arch/s390/lib/uaccess_std.c b/arch/s390/lib/uaccess_std.c index a6c4f7e..bb1a7ee 100644 --- a/arch/s390/lib/uaccess_std.c +++ b/arch/s390/lib/uaccess_std.c @@ -255,7 +255,7 @@ size_t strncpy_from_user_std(size_t size, const char __user *src, char *dst) : "0" (-EFAULT), "d" (oparg), "a" (uaddr), \ "m" (*uaddr) : "cc"); -int futex_atomic_op_std(int op, int __user *uaddr, int oparg, int *old) +int futex_atomic_op_std(int op, u32 __user *uaddr, int oparg, int *old) { int oldval = 0, newval, ret; @@ -287,19 +287,21 @@ int futex_atomic_op_std(int op, int __user *uaddr, int oparg, int *old) return ret; } -int futex_atomic_cmpxchg_std(int __user *uaddr, int oldval, int newval) +int futex_atomic_cmpxchg_std(u32 *uval, u32 __user *uaddr, + u32 oldval, u32 newval) { int ret; asm volatile( " sacf 256\n" "0: cs %1,%4,0(%5)\n" - "1: lr %0,%1\n" + "1: la %0,0\n" "2: sacf 0\n" EX_TABLE(0b,2b) EX_TABLE(1b,2b) : "=d" (ret), "+d" (oldval), "=m" (*uaddr) : "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr) : "cc", "memory" ); + *uval = oldval; return ret; } diff --git a/arch/sh/include/asm/futex-irq.h b/arch/sh/include/asm/futex-irq.h index a9f16a7..6cb9f19 100644 --- a/arch/sh/include/asm/futex-irq.h +++ b/arch/sh/include/asm/futex-irq.h @@ -3,7 +3,7 @@ #include -static inline int atomic_futex_op_xchg_set(int oparg, int __user *uaddr, +static inline int atomic_futex_op_xchg_set(int oparg, u32 __user *uaddr, int *oldval) { unsigned long flags; @@ -20,7 +20,7 @@ static inline int atomic_futex_op_xchg_set(int oparg, int __user *uaddr, return ret; } -static inline int atomic_futex_op_xchg_add(int oparg, int __user *uaddr, +static inline int atomic_futex_op_xchg_add(int oparg, u32 __user *uaddr, int *oldval) { unsigned long flags; @@ -37,7 +37,7 @@ static inline int atomic_futex_op_xchg_add(int oparg, int __user *uaddr, return ret; } -static inline int atomic_futex_op_xchg_or(int oparg, int __user *uaddr, +static inline int atomic_futex_op_xchg_or(int oparg, u32 __user *uaddr, int *oldval) { unsigned long flags; @@ -54,7 +54,7 @@ static inline int atomic_futex_op_xchg_or(int oparg, int __user *uaddr, return ret; } -static inline int atomic_futex_op_xchg_and(int oparg, int __user *uaddr, +static inline int atomic_futex_op_xchg_and(int oparg, u32 __user *uaddr, int *oldval) { unsigned long flags; @@ -71,7 +71,7 @@ static inline int atomic_futex_op_xchg_and(int oparg, int __user *uaddr, return ret; } -static inline int atomic_futex_op_xchg_xor(int oparg, int __user *uaddr, +static inline int atomic_futex_op_xchg_xor(int oparg, u32 __user *uaddr, int *oldval) { unsigned long flags; @@ -88,11 +88,13 @@ static inline int atomic_futex_op_xchg_xor(int oparg, int __user *uaddr, return ret; } -static inline int atomic_futex_op_cmpxchg_inatomic(int __user *uaddr, - int oldval, int newval) +static inline int atomic_futex_op_cmpxchg_inatomic(u32 *uval, + u32 __user *uaddr, + u32 oldval, u32 newval) { unsigned long flags; - int ret, prev = 0; + int ret; + u32 prev = 0; local_irq_save(flags); @@ -102,10 +104,8 @@ static inline int atomic_futex_op_cmpxchg_inatomic(int __user *uaddr, local_irq_restore(flags); - if (ret) - return ret; - - return prev; + *uval = prev; + return ret; } #endif /* __ASM_SH_FUTEX_IRQ_H */ diff --git a/arch/sh/include/asm/futex.h b/arch/sh/include/asm/futex.h index 68256ec..7be39a6 100644 --- a/arch/sh/include/asm/futex.h +++ b/arch/sh/include/asm/futex.h @@ -10,7 +10,7 @@ /* XXX: UP variants, fix for SH-4A and SMP.. */ #include -static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr) +static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr) { int op = (encoded_op >> 28) & 7; int cmp = (encoded_op >> 24) & 15; @@ -21,7 +21,7 @@ static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr) if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) oparg = 1 << oparg; - if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; pagefault_disable(); @@ -65,12 +65,13 @@ static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr) } static inline int -futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval) +futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, + u32 oldval, u32 newval) { - if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; - return atomic_futex_op_cmpxchg_inatomic(uaddr, oldval, newval); + return atomic_futex_op_cmpxchg_inatomic(uval, uaddr, oldval, newval); } #endif /* __KERNEL__ */ diff --git a/arch/sparc/include/asm/futex_64.h b/arch/sparc/include/asm/futex_64.h index 47f9583..444e7be 100644 --- a/arch/sparc/include/asm/futex_64.h +++ b/arch/sparc/include/asm/futex_64.h @@ -30,7 +30,7 @@ : "r" (uaddr), "r" (oparg), "i" (-EFAULT) \ : "memory") -static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr) +static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr) { int op = (encoded_op >> 28) & 7; int cmp = (encoded_op >> 24) & 15; @@ -38,7 +38,7 @@ static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr) int cmparg = (encoded_op << 20) >> 20; int oldval = 0, ret, tem; - if (unlikely(!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))) + if (unlikely(!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))) return -EFAULT; if (unlikely((((unsigned long) uaddr) & 0x3UL))) return -EINVAL; @@ -85,26 +85,30 @@ static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr) } static inline int -futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval) +futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, + u32 oldval, u32 newval) { + int ret = 0; + __asm__ __volatile__( - "\n1: casa [%3] %%asi, %2, %0\n" + "\n1: casa [%4] %%asi, %3, %1\n" "2:\n" " .section .fixup,#alloc,#execinstr\n" " .align 4\n" "3: sethi %%hi(2b), %0\n" " jmpl %0 + %%lo(2b), %%g0\n" - " mov %4, %0\n" + " mov %5, %0\n" " .previous\n" " .section __ex_table,\"a\"\n" " .align 4\n" " .word 1b, 3b\n" " .previous\n" - : "=r" (newval) - : "0" (newval), "r" (oldval), "r" (uaddr), "i" (-EFAULT) + : "+r" (ret), "=r" (newval) + : "1" (newval), "r" (oldval), "r" (uaddr), "i" (-EFAULT) : "memory"); - return newval; + *uval = newval; + return ret; } #endif /* !(_SPARC64_FUTEX_H) */ diff --git a/arch/tile/include/asm/futex.h b/arch/tile/include/asm/futex.h index fe0d10d..d03ec12 100644 --- a/arch/tile/include/asm/futex.h +++ b/arch/tile/include/asm/futex.h @@ -29,16 +29,16 @@ #include #include -extern struct __get_user futex_set(int __user *v, int i); -extern struct __get_user futex_add(int __user *v, int n); -extern struct __get_user futex_or(int __user *v, int n); -extern struct __get_user futex_andn(int __user *v, int n); -extern struct __get_user futex_cmpxchg(int __user *v, int o, int n); +extern struct __get_user futex_set(u32 __user *v, int i); +extern struct __get_user futex_add(u32 __user *v, int n); +extern struct __get_user futex_or(u32 __user *v, int n); +extern struct __get_user futex_andn(u32 __user *v, int n); +extern struct __get_user futex_cmpxchg(u32 __user *v, int o, int n); #ifndef __tilegx__ -extern struct __get_user futex_xor(int __user *v, int n); +extern struct __get_user futex_xor(u32 __user *v, int n); #else -static inline struct __get_user futex_xor(int __user *uaddr, int n) +static inline struct __get_user futex_xor(u32 __user *uaddr, int n) { struct __get_user asm_ret = __get_user_4(uaddr); if (!asm_ret.err) { @@ -53,7 +53,7 @@ static inline struct __get_user futex_xor(int __user *uaddr, int n) } #endif -static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr) +static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr) { int op = (encoded_op >> 28) & 7; int cmp = (encoded_op >> 24) & 15; @@ -65,7 +65,7 @@ static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr) if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) oparg = 1 << oparg; - if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; pagefault_disable(); @@ -119,16 +119,17 @@ static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr) return ret; } -static inline int futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, - int newval) +static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, + u32 oldval, u32 newval) { struct __get_user asm_ret; - if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; asm_ret = futex_cmpxchg(uaddr, oldval, newval); - return asm_ret.err ? asm_ret.err : asm_ret.val; + *uval = asm_ret.val; + return asm_ret.err; } #ifndef __tilegx__ diff --git a/arch/x86/include/asm/futex.h b/arch/x86/include/asm/futex.h index 1f11ce4..d09bb03 100644 --- a/arch/x86/include/asm/futex.h +++ b/arch/x86/include/asm/futex.h @@ -37,7 +37,7 @@ "+m" (*uaddr), "=&r" (tem) \ : "r" (oparg), "i" (-EFAULT), "1" (0)) -static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr) +static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr) { int op = (encoded_op >> 28) & 7; int cmp = (encoded_op >> 24) & 15; @@ -48,7 +48,7 @@ static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr) if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) oparg = 1 << oparg; - if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; #if defined(CONFIG_X86_32) && !defined(CONFIG_X86_BSWAP) @@ -109,9 +109,10 @@ static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr) return ret; } -static inline int futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, - int newval) +static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, + u32 oldval, u32 newval) { + int ret = 0; #if defined(CONFIG_X86_32) && !defined(CONFIG_X86_BSWAP) /* Real i386 machines have no cmpxchg instruction */ @@ -119,21 +120,22 @@ static inline int futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, return -ENOSYS; #endif - if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; - asm volatile("1:\t" LOCK_PREFIX "cmpxchgl %3, %1\n" + asm volatile("1:\t" LOCK_PREFIX "cmpxchgl %4, %2\n" "2:\t.section .fixup, \"ax\"\n" - "3:\tmov %2, %0\n" + "3:\tmov %3, %0\n" "\tjmp 2b\n" "\t.previous\n" _ASM_EXTABLE(1b, 3b) - : "=a" (oldval), "+m" (*uaddr) - : "i" (-EFAULT), "r" (newval), "0" (oldval) + : "+r" (ret), "=a" (oldval), "+m" (*uaddr) + : "i" (-EFAULT), "r" (newval), "1" (oldval) : "memory" ); - return oldval; + *uval = oldval; + return ret; } #endif diff --git a/include/asm-generic/futex.h b/include/asm-generic/futex.h index 3c2344f..01f227e 100644 --- a/include/asm-generic/futex.h +++ b/include/asm-generic/futex.h @@ -6,7 +6,7 @@ #include static inline int -futex_atomic_op_inuser (int encoded_op, int __user *uaddr) +futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr) { int op = (encoded_op >> 28) & 7; int cmp = (encoded_op >> 24) & 15; @@ -16,7 +16,7 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr) if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) oparg = 1 << oparg; - if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int))) + if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; pagefault_disable(); @@ -48,7 +48,8 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr) } static inline int -futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval) +futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, + u32 oldval, u32 newval) { return -ENOSYS; } diff --git a/kernel/futex.c b/kernel/futex.c index 3184d3b..53b783f 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -381,15 +381,16 @@ static struct futex_q *futex_top_waiter(struct futex_hash_bucket *hb, return NULL; } -static u32 cmpxchg_futex_value_locked(u32 __user *uaddr, u32 uval, u32 newval) +static int cmpxchg_futex_value_locked(u32 *curval, u32 __user *uaddr, + u32 uval, u32 newval) { - u32 curval; + int ret; pagefault_disable(); - curval = futex_atomic_cmpxchg_inatomic(uaddr, uval, newval); + ret = futex_atomic_cmpxchg_inatomic(curval, uaddr, uval, newval); pagefault_enable(); - return curval; + return ret; } static int get_futex_value_locked(u32 *dest, u32 __user *from) @@ -688,9 +689,7 @@ retry: if (set_waiters) newval |= FUTEX_WAITERS; - curval = cmpxchg_futex_value_locked(uaddr, 0, newval); - - if (unlikely(curval == -EFAULT)) + if (unlikely(cmpxchg_futex_value_locked(&curval, uaddr, 0, newval))) return -EFAULT; /* @@ -728,9 +727,7 @@ retry: lock_taken = 1; } - curval = cmpxchg_futex_value_locked(uaddr, uval, newval); - - if (unlikely(curval == -EFAULT)) + if (unlikely(cmpxchg_futex_value_locked(&curval, uaddr, uval, newval))) return -EFAULT; if (unlikely(curval != uval)) goto retry; @@ -843,9 +840,7 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this) newval = FUTEX_WAITERS | task_pid_vnr(new_owner); - curval = cmpxchg_futex_value_locked(uaddr, uval, newval); - - if (curval == -EFAULT) + if (cmpxchg_futex_value_locked(&curval, uaddr, uval, newval)) ret = -EFAULT; else if (curval != uval) ret = -EINVAL; @@ -880,10 +875,8 @@ static int unlock_futex_pi(u32 __user *uaddr, u32 uval) * There is no waiter, so we unlock the futex. The owner died * bit has not to be preserved here. We are the owner: */ - oldval = cmpxchg_futex_value_locked(uaddr, uval, 0); - - if (oldval == -EFAULT) - return oldval; + if (cmpxchg_futex_value_locked(&oldval, uaddr, uval, 0)) + return -EFAULT; if (oldval != uval) return -EAGAIN; @@ -1578,9 +1571,7 @@ retry: while (1) { newval = (uval & FUTEX_OWNER_DIED) | newtid; - curval = cmpxchg_futex_value_locked(uaddr, uval, newval); - - if (curval == -EFAULT) + if (cmpxchg_futex_value_locked(&curval, uaddr, uval, newval)) goto handle_fault; if (curval == uval) break; @@ -2073,11 +2064,9 @@ retry: * again. If it succeeds then we can return without waking * anyone else up: */ - if (!(uval & FUTEX_OWNER_DIED)) - uval = cmpxchg_futex_value_locked(uaddr, task_pid_vnr(current), 0); - - - if (unlikely(uval == -EFAULT)) + if (!(uval & FUTEX_OWNER_DIED) && + unlikely(cmpxchg_futex_value_locked(&uval, uaddr, + task_pid_vnr(current), 0))) goto pi_faulted; /* * Rare case: we managed to release the lock atomically, @@ -2464,9 +2453,7 @@ retry: * userspace. */ mval = (uval & FUTEX_WAITERS) | FUTEX_OWNER_DIED; - nval = futex_atomic_cmpxchg_inatomic(uaddr, uval, mval); - - if (nval == -EFAULT) + if (futex_atomic_cmpxchg_inatomic(&nval, uaddr, uval, mval)) return -1; if (nval != uval) @@ -2679,8 +2666,7 @@ static int __init futex_init(void) * implementation, the non-functional ones will return * -ENOSYS. */ - curval = cmpxchg_futex_value_locked(NULL, 0, 0); - if (curval == -EFAULT) + if (cmpxchg_futex_value_locked(&curval, NULL, 0, 0) == -EFAULT) futex_cmpxchg_enabled = 1; for (i = 0; i < ARRAY_SIZE(futex_queues); i++) { -- Michel "Walken" Lespinasse A program is never fully debugged until the last user dies. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/