* [PATCH] Unwire set/get_robust_list @ 2006-09-04 19:27 Andreas Schwab 2006-09-04 22:32 ` David Woodhouse 2006-09-05 21:41 ` David Woodhouse 0 siblings, 2 replies; 9+ messages in thread From: Andreas Schwab @ 2006-09-04 19:27 UTC (permalink / raw) To: linuxppc-dev The syscalls set/get_robust_list must not be wired up until futex_atomic_cmpxchg_inatomic is implemented. Otherwise the kernel will hang in handle_futex_death. Signed-off-by: Andreas Schwab <schwab@suse.de> Index: linux-2.6.18-rc6/include/asm-powerpc/systbl.h =================================================================== --- linux-2.6.18-rc6.orig/include/asm-powerpc/systbl.h 2006-09-04 18:12:43.000000000 +0200 +++ linux-2.6.18-rc6/include/asm-powerpc/systbl.h 2006-09-04 20:54:42.000000000 +0200 @@ -302,5 +302,5 @@ SYSCALL_SPU(symlinkat) SYSCALL_SPU(readlinkat) SYSCALL_SPU(fchmodat) SYSCALL_SPU(faccessat) -COMPAT_SYS_SPU(get_robust_list) -COMPAT_SYS_SPU(set_robust_list) +SYSCALL(ni_syscall) +SYSCALL(ni_syscall) Index: linux-2.6.18-rc6/include/asm-powerpc/unistd.h =================================================================== --- linux-2.6.18-rc6.orig/include/asm-powerpc/unistd.h 2006-09-04 18:12:43.000000000 +0200 +++ linux-2.6.18-rc6/include/asm-powerpc/unistd.h 2006-09-04 20:55:30.000000000 +0200 @@ -321,8 +321,8 @@ #define __NR_readlinkat 296 #define __NR_fchmodat 297 #define __NR_faccessat 298 -#define __NR_get_robust_list 299 -#define __NR_set_robust_list 300 +/* Number 299 reserved for get_robust_list */ +/* Number 300 reserved for set_robust_list */ #ifdef __KERNEL__ Andreas. -- Andreas Schwab, SuSE Labs, schwab@suse.de SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany PGP key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different." ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] Unwire set/get_robust_list 2006-09-04 19:27 [PATCH] Unwire set/get_robust_list Andreas Schwab @ 2006-09-04 22:32 ` David Woodhouse 2006-09-04 23:29 ` Andreas Schwab 2006-09-04 23:58 ` Paul Mackerras 2006-09-05 21:41 ` David Woodhouse 1 sibling, 2 replies; 9+ messages in thread From: David Woodhouse @ 2006-09-04 22:32 UTC (permalink / raw) To: Andreas Schwab; +Cc: linuxppc-dev On Mon, 2006-09-04 at 21:27 +0200, Andreas Schwab wrote: > The syscalls set/get_robust_list must not be wired up until > futex_atomic_cmpxchg_inatomic is implemented. Otherwise the kernel will > hang in handle_futex_death. Something like this? Untested-but-otherwise-Signed-off-by: David Woodhouse <dwmw2@infradead.org> diff --git a/include/asm-powerpc/futex.h b/include/asm-powerpc/futex.h index f1b3c00..e8ff12c 100644 --- a/include/asm-powerpc/futex.h +++ b/include/asm-powerpc/futex.h @@ -84,7 +84,30 @@ static inline int futex_atomic_op_inuser static inline int futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval) { - return -ENOSYS; + int prev; + + __asm__ __volatile__ ( + LWSYNC_ON_SMP +"1: lwarx %0,0,%2 # futex_atomic_cmpxchg_inatomic\n\ + cmpw 0,%0,%3\n\ + bne- 3f\n" + PPC405_ERR77(0,%2) +"2: stwcx. %4,0,%2\n\ + bne- 1b\n" + ISYNC_ON_SMP +"3: .section .fixup,\"ax\"\n\ +4: li %0,%5\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" (uaddr), "r" (oldval), "r" (newval), "i" (-EFAULT) + : "cc", "memory"); + + return prev; } #endif /* __KERNEL__ */ -- dwmw2 ^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH] Unwire set/get_robust_list 2006-09-04 22:32 ` David Woodhouse @ 2006-09-04 23:29 ` Andreas Schwab 2006-09-12 23:04 ` Paul Mackerras 2006-09-04 23:58 ` Paul Mackerras 1 sibling, 1 reply; 9+ messages in thread From: Andreas Schwab @ 2006-09-04 23:29 UTC (permalink / raw) To: David Woodhouse; +Cc: linuxppc-dev David Woodhouse <dwmw2@infradead.org> writes: > On Mon, 2006-09-04 at 21:27 +0200, Andreas Schwab wrote: >> The syscalls set/get_robust_list must not be wired up until >> futex_atomic_cmpxchg_inatomic is implemented. Otherwise the kernel will >> hang in handle_futex_death. > > Something like this? > > Untested-but-otherwise-Signed-off-by: David Woodhouse <dwmw2@infradead.org> Thanks, sucessfully tested on 32bit (with the nptl testsuite of glibc). Will do some 64bit testing tomorrow. Andreas. -- Andreas Schwab, SuSE Labs, schwab@suse.de SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany PGP key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different." ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] Unwire set/get_robust_list 2006-09-04 23:29 ` Andreas Schwab @ 2006-09-12 23:04 ` Paul Mackerras 2006-09-13 8:56 ` Andreas Schwab 2006-09-13 12:54 ` Andreas Schwab 0 siblings, 2 replies; 9+ messages in thread From: Paul Mackerras @ 2006-09-12 23:04 UTC (permalink / raw) To: Andreas Schwab; +Cc: linuxppc-dev, David Woodhouse Andreas Schwab writes: > Thanks, sucessfully tested on 32bit (with the nptl testsuite of glibc). > Will do some 64bit testing tomorrow. Did you do that testing? What was the result? Could you test David's latest patch without the memory clobber? For reference, here it is. Thanks, Paul. diff --git a/include/asm-powerpc/futex.h b/include/asm-powerpc/futex.h index f1b3c00..936422e 100644 --- a/include/asm-powerpc/futex.h +++ b/include/asm-powerpc/futex.h @@ -84,7 +84,33 @@ static inline int futex_atomic_op_inuser static inline int futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval) { - return -ENOSYS; + int prev; + + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) + return -EFAULT; + + __asm__ __volatile__ ( + LWSYNC_ON_SMP +"1: lwarx %0,0,%2 # futex_atomic_cmpxchg_inatomic\n\ + cmpw 0,%0,%3\n\ + bne- 3f\n" + PPC405_ERR77(0,%2) +"2: stwcx. %4,0,%2\n\ + bne- 1b\n" + ISYNC_ON_SMP +"3: .section .fixup,\"ax\"\n\ +4: li %0,%5\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" (uaddr), "r" (oldval), "r" (newval), "i" (-EFAULT) + : "cc"); + + return prev; } #endif /* __KERNEL__ */ ^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH] Unwire set/get_robust_list 2006-09-12 23:04 ` Paul Mackerras @ 2006-09-13 8:56 ` Andreas Schwab 2006-09-13 12:54 ` Andreas Schwab 1 sibling, 0 replies; 9+ messages in thread From: Andreas Schwab @ 2006-09-13 8:56 UTC (permalink / raw) To: Paul Mackerras; +Cc: linuxppc-dev, David Woodhouse Paul Mackerras <paulus@samba.org> writes: > Andreas Schwab writes: > >> Thanks, sucessfully tested on 32bit (with the nptl testsuite of glibc). >> Will do some 64bit testing tomorrow. > > Did you do that testing? What was the result? Yes, I did, successful. > Could you test David's latest patch without the memory clobber? I'll do. Andreas. -- Andreas Schwab, SuSE Labs, schwab@suse.de SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany PGP key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different." ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] Unwire set/get_robust_list 2006-09-12 23:04 ` Paul Mackerras 2006-09-13 8:56 ` Andreas Schwab @ 2006-09-13 12:54 ` Andreas Schwab 1 sibling, 0 replies; 9+ messages in thread From: Andreas Schwab @ 2006-09-13 12:54 UTC (permalink / raw) To: Paul Mackerras; +Cc: linuxppc-dev, David Woodhouse Paul Mackerras <paulus@samba.org> writes: > Could you test David's latest patch without the memory clobber? Looks good (only tested on ppc64 kernel this time, but both 32 and 64 bit userland). Andreas. -- Andreas Schwab, SuSE Labs, schwab@suse.de SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany PGP key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different." ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] Unwire set/get_robust_list 2006-09-04 22:32 ` David Woodhouse 2006-09-04 23:29 ` Andreas Schwab @ 2006-09-04 23:58 ` Paul Mackerras 2006-09-05 4:53 ` David Woodhouse 1 sibling, 1 reply; 9+ messages in thread From: Paul Mackerras @ 2006-09-04 23:58 UTC (permalink / raw) To: David Woodhouse; +Cc: linuxppc-dev David Woodhouse writes: > Something like this? Don't we need an access_ok() test in there? Otherwise, looks fine to me. Thanks, Paul. ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] Unwire set/get_robust_list 2006-09-04 23:58 ` Paul Mackerras @ 2006-09-05 4:53 ` David Woodhouse 0 siblings, 0 replies; 9+ messages in thread From: David Woodhouse @ 2006-09-05 4:53 UTC (permalink / raw) To: Paul Mackerras; +Cc: linuxppc-dev On Tue, 2006-09-05 at 09:58 +1000, Paul Mackerras wrote: > Don't we need an access_ok() test in there? Otherwise, looks fine to > me. Oops, good point. Like this then... Do we actually need the memory clobber, btw? We're not using this for locking in kernel space. [PATCH] Implement PowerPC futex_atomic_cmpxchg_inatomic(). The sys_[gs]et_robust_list() syscalls were wired up on PowerPC but didn't work correctly because futex_atomic_cmpxchg_inatomic() wasn't implemented. Implement it, based on __cmpxchg_u32() Signed-off-by: David Woodhouse <dwmw2@infradead.org> diff --git a/include/asm-powerpc/futex.h b/include/asm-powerpc/futex.h index f1b3c00..936422e 100644 --- a/include/asm-powerpc/futex.h +++ b/include/asm-powerpc/futex.h @@ -84,7 +84,33 @@ static inline int futex_atomic_op_inuser static inline int futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval) { - return -ENOSYS; + int prev; + + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) + return -EFAULT; + + __asm__ __volatile__ ( + LWSYNC_ON_SMP +"1: lwarx %0,0,%2 # futex_atomic_cmpxchg_inatomic\n\ + cmpw 0,%0,%3\n\ + bne- 3f\n" + PPC405_ERR77(0,%2) +"2: stwcx. %4,0,%2\n\ + bne- 1b\n" + ISYNC_ON_SMP +"3: .section .fixup,\"ax\"\n\ +4: li %0,%5\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" (uaddr), "r" (oldval), "r" (newval), "i" (-EFAULT) + : "cc", "memory"); + + return prev; } #endif /* __KERNEL__ */ -- dwmw2 ^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH] Unwire set/get_robust_list 2006-09-04 19:27 [PATCH] Unwire set/get_robust_list Andreas Schwab 2006-09-04 22:32 ` David Woodhouse @ 2006-09-05 21:41 ` David Woodhouse 1 sibling, 0 replies; 9+ messages in thread From: David Woodhouse @ 2006-09-05 21:41 UTC (permalink / raw) To: Andreas Schwab; +Cc: linuxppc-dev On Mon, 2006-09-04 at 21:27 +0200, Andreas Schwab wrote: > The syscalls set/get_robust_list must not be wired up until > futex_atomic_cmpxchg_inatomic is implemented. Otherwise the kernel > will hang in handle_futex_death. Either Andreas' or my patch ought to go into 2.6.18, since [gs]et_robust_list() are otherwise broken there. -- dwmw2 ^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2006-09-13 12:54 UTC | newest] Thread overview: 9+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2006-09-04 19:27 [PATCH] Unwire set/get_robust_list Andreas Schwab 2006-09-04 22:32 ` David Woodhouse 2006-09-04 23:29 ` Andreas Schwab 2006-09-12 23:04 ` Paul Mackerras 2006-09-13 8:56 ` Andreas Schwab 2006-09-13 12:54 ` Andreas Schwab 2006-09-04 23:58 ` Paul Mackerras 2006-09-05 4:53 ` David Woodhouse 2006-09-05 21:41 ` David Woodhouse
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