From 7c60c48f58a78195acc1f71c9a9d01958c02ab89 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Sat, 21 Jan 2012 13:34:05 -0800 Subject: sysctl: Improve the sysctl sanity checks - Stop validating subdirectories now that we only register leaf tables - Cleanup and improve the duplicate filename check. * Run the duplicate filename check under the sysctl_lock to guarantee we never add duplicate names. * Reduce the duplicate filename check to nearly O(M*N) where M is the number of entries in tthe table we are registering and N is the number of entries in the directory before we got there. - Move the duplicate filename check into it's own function and call it directtly from __register_sysctl_table - Kill the config option as the sanity checks are now cheap enough the config option is unnecessary. The original reason for the config option was because we had a huge table used to verify the proc filename to binary sysctl mapping. That table has now evolved into the binary_sysctl translation layer and is no longer part of the sysctl_check code. - Tighten up the permission checks. Guarnateeing that files only have read or write permissions. - Removed redudant check for parents having a procname as now everything has a procname. - Generalize the backtrace logic so that we print a backtrace from any failure of __register_sysctl_table that was not caused by a memmory allocation failure. The backtrace allows us to track down who erroneously registered a sysctl table. Bechmark before (CONFIG_SYSCTL_CHECK=y): make-dummies 0 999 -> 12s rmmod dummy -> 0.08s Bechmark before (CONFIG_SYSCTL_CHECK=n): make-dummies 0 999 -> 0.7s rmmod dummy -> 0.06s make-dummies 0 99999 -> 1m13s rmmod dummy -> 0.38s Benchmark after: make-dummies 0 999 -> 0.65s rmmod dummy -> 0.055s make-dummies 0 9999 -> 1m10s rmmod dummy -> 0.39s The sysctl sanity checks now impose no measurable cost. Signed-off-by: Eric W. Biederman --- lib/Kconfig.debug | 8 -------- 1 file changed, 8 deletions(-) (limited to 'lib/Kconfig.debug') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 8745ac7d1f75..943a6182cdf2 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1113,14 +1113,6 @@ config LATENCYTOP Enable this option if you want to use the LatencyTOP tool to find out which userspace is blocking on what kernel operations. -config SYSCTL_SYSCALL_CHECK - bool "Sysctl checks" - depends on SYSCTL - ---help--- - sys_sysctl uses binary paths that have been found challenging - to properly maintain and use. This enables checks that help - you to keep things correct. - source mm/Kconfig.debug source kernel/trace/Kconfig -- cgit v1.2.3 From e335e3eb82dada2765297f6ba501afc7555aba10 Mon Sep 17 00:00:00 2001 From: Raghavendra K T Date: Thu, 22 Mar 2012 15:25:08 +0530 Subject: locking/kconfig: Simplify INLINE_SPIN_UNLOCK usage Get rid of INLINE_SPIN_UNLOCK entirely replacing it with UNINLINE_SPIN_UNLOCK instead of the reverse meaning. Whoever wants to change the default spinlock inlining behavior and uninline the spinlocks for some weird reason, such as spinlock debugging, paravirt etc. can now all just select UNINLINE_SPIN_UNLOCK Original discussion at: https://lkml.org/lkml/2012/3/21/357 Suggested-by: Linus Torvalds Signed-off-by: Raghavendra K T Cc: Linus Torvalds Cc: Ralf Baechle Cc: Chris Metcalf Cc: Chris Zankel Cc: linux-mips@linux-mips.org Link: http://lkml.kernel.org/r/20120322095502.30866.75756.sendpatchset@codeblue [ tidied up the changelog a bit ] Signed-off-by: Ingo Molnar --- arch/mips/configs/db1300_defconfig | 2 +- arch/xtensa/configs/iss_defconfig | 2 +- include/linux/spinlock_api_smp.h | 2 +- kernel/Kconfig.locks | 4 ++-- kernel/Kconfig.preempt | 1 + kernel/spinlock.c | 2 +- lib/Kconfig.debug | 1 + 7 files changed, 8 insertions(+), 6 deletions(-) (limited to 'lib/Kconfig.debug') diff --git a/arch/mips/configs/db1300_defconfig b/arch/mips/configs/db1300_defconfig index c38b190151c4..3590ab5d9791 100644 --- a/arch/mips/configs/db1300_defconfig +++ b/arch/mips/configs/db1300_defconfig @@ -133,7 +133,7 @@ CONFIG_BLK_DEV_BSG=y CONFIG_IOSCHED_NOOP=y CONFIG_DEFAULT_NOOP=y CONFIG_DEFAULT_IOSCHED="noop" -CONFIG_INLINE_SPIN_UNLOCK=y +# CONFIG_UNINLINE_SPIN_UNLOCK is not set CONFIG_INLINE_SPIN_UNLOCK_IRQ=y CONFIG_INLINE_READ_UNLOCK=y CONFIG_INLINE_READ_UNLOCK_IRQ=y diff --git a/arch/xtensa/configs/iss_defconfig b/arch/xtensa/configs/iss_defconfig index f932b30b47fb..ddab37b24741 100644 --- a/arch/xtensa/configs/iss_defconfig +++ b/arch/xtensa/configs/iss_defconfig @@ -113,7 +113,7 @@ CONFIG_DEFAULT_IOSCHED="noop" # CONFIG_INLINE_SPIN_LOCK_BH is not set # CONFIG_INLINE_SPIN_LOCK_IRQ is not set # CONFIG_INLINE_SPIN_LOCK_IRQSAVE is not set -CONFIG_INLINE_SPIN_UNLOCK=y +# CONFIG_UNINLINE_SPIN_UNLOCK is not set # CONFIG_INLINE_SPIN_UNLOCK_BH is not set CONFIG_INLINE_SPIN_UNLOCK_IRQ=y # CONFIG_INLINE_SPIN_UNLOCK_IRQRESTORE is not set diff --git a/include/linux/spinlock_api_smp.h b/include/linux/spinlock_api_smp.h index e253ccd7a604..51df117abe46 100644 --- a/include/linux/spinlock_api_smp.h +++ b/include/linux/spinlock_api_smp.h @@ -67,7 +67,7 @@ _raw_spin_unlock_irqrestore(raw_spinlock_t *lock, unsigned long flags) #define _raw_spin_trylock_bh(lock) __raw_spin_trylock_bh(lock) #endif -#ifdef CONFIG_INLINE_SPIN_UNLOCK +#ifndef CONFIG_UNINLINE_SPIN_UNLOCK #define _raw_spin_unlock(lock) __raw_spin_unlock(lock) #endif diff --git a/kernel/Kconfig.locks b/kernel/Kconfig.locks index 5068e2a4e75f..2251882daf53 100644 --- a/kernel/Kconfig.locks +++ b/kernel/Kconfig.locks @@ -124,8 +124,8 @@ config INLINE_SPIN_LOCK_IRQSAVE def_bool !DEBUG_SPINLOCK && !GENERIC_LOCKBREAK && \ ARCH_INLINE_SPIN_LOCK_IRQSAVE -config INLINE_SPIN_UNLOCK - def_bool !DEBUG_SPINLOCK && (!PREEMPT || ARCH_INLINE_SPIN_UNLOCK) +config UNINLINE_SPIN_UNLOCK + bool config INLINE_SPIN_UNLOCK_BH def_bool !DEBUG_SPINLOCK && ARCH_INLINE_SPIN_UNLOCK_BH diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt index 24e7cb0ba26a..3f9c97419f02 100644 --- a/kernel/Kconfig.preempt +++ b/kernel/Kconfig.preempt @@ -36,6 +36,7 @@ config PREEMPT_VOLUNTARY config PREEMPT bool "Preemptible Kernel (Low-Latency Desktop)" select PREEMPT_COUNT + select UNINLINE_SPIN_UNLOCK if !ARCH_INLINE_SPIN_UNLOCK help This option reduces the latency of the kernel by making all kernel code (that is not executing in a critical section) diff --git a/kernel/spinlock.c b/kernel/spinlock.c index 84c7d96918bf..5cdd8065a3ce 100644 --- a/kernel/spinlock.c +++ b/kernel/spinlock.c @@ -163,7 +163,7 @@ void __lockfunc _raw_spin_lock_bh(raw_spinlock_t *lock) EXPORT_SYMBOL(_raw_spin_lock_bh); #endif -#ifndef CONFIG_INLINE_SPIN_UNLOCK +#ifdef CONFIG_UNINLINE_SPIN_UNLOCK void __lockfunc _raw_spin_unlock(raw_spinlock_t *lock) { __raw_spin_unlock(lock); diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 05037dc9bde7..f32a41f2a82a 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -499,6 +499,7 @@ config RT_MUTEX_TESTER config DEBUG_SPINLOCK bool "Spinlock and rw-lock debugging: basic checks" depends on DEBUG_KERNEL + select UNINLINE_SPIN_UNLOCK help Say Y here and build SMP to catch missing spinlock initialization and certain other kinds of spinlock errors commonly made. This is -- cgit v1.2.3