From 05f54c13cd0c33694eec39a265475c5d6cf223cf Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Thu, 16 Apr 2009 21:55:29 +0100 Subject: Revert "kobject: don't block for each kobject_uevent". This reverts commit f520360d93cdc37de5d972dac4bf3bdef6a7f6a7. Tetsuo Handa, running a kernel with CONFIG_DEBUG_PAGEALLOC=y and CONFIG_UEVENT_HELPER_PATH=/sbin/hotplug, has been hitting RCU detected CPU stalls: it's been spinning in the loop where do_execve() counts up the args (but why wasn't fixup_exception working? dunno). The recent change, switching kobject_uevent_env() from UMH_WAIT_EXEC to UMH_NO_WAIT, is broken: the exec uses args on the local stack here, and an env which is kfreed as soon as call_usermodehelper() returns. It very much needs to wait for the exec to be done. An alternative would be to keep the UMH_NO_WAIT, and complicate the code to allocate and free these resources correctly? but no, as GregKH pointed out when making the commit, CONFIG_UEVENT_HELPER_PATH="" is a much better optimization - though some distros are still saying /sbin/hotplug in their .config, yet with no such binary in their initrd or their root. Reported-by: Tetsuo Handa Signed-off-by: Hugh Dickins Acked-by: Greg Kroah-Hartman Acked-by: Arjan van de Ven Acked-by: Will Newton Signed-off-by: Linus Torvalds --- lib/kobject_uevent.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c index 97a777ad4f5..dafeecf5b14 100644 --- a/lib/kobject_uevent.c +++ b/lib/kobject_uevent.c @@ -258,7 +258,7 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, goto exit; retval = call_usermodehelper(argv[0], argv, - env->envp, UMH_NO_WAIT); + env->envp, UMH_WAIT_EXEC); } exit: -- cgit v1.2.3-70-g09d2 From d094cbe998eb566d47552aa9d3c26c9123a7b858 Mon Sep 17 00:00:00 2001 From: Kay Sievers Date: Fri, 3 Apr 2009 19:04:15 +0200 Subject: driver core: allow non-root users to listen to uevents Users can read sysfs files, there is no reason they should not be allowed to listen to uevents. This lets xorg and other userspace programs properly get these messages without having to be root. Signed-off-by: Kay Sievers Signed-off-by: Greg Kroah-Hartman --- lib/kobject_uevent.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c index dafeecf5b14..920a3ca6e25 100644 --- a/lib/kobject_uevent.c +++ b/lib/kobject_uevent.c @@ -328,7 +328,7 @@ static int __init kobject_uevent_init(void) "kobject_uevent: unable to create netlink socket!\n"); return -ENODEV; } - + netlink_set_nonroot(NETLINK_KOBJECT_UEVENT, NL_NONROOT_RECV); return 0; } -- cgit v1.2.3-70-g09d2 From 8a577ffc75d9194fe8cdb7479236f2081c26ca1f Mon Sep 17 00:00:00 2001 From: Kay Sievers Date: Sat, 18 Apr 2009 15:05:45 -0700 Subject: driver: dont update dev_name via device_add path notice one system /proc/iomem some entries missed the name for pci_devices it turns that dev->dev.kobj name is changed after device_add. for pci code: via acpi_pci_root_driver.ops.add (aka acpi_pci_root_add) ==> pci_acpi_scan_root is used to scan pci bus/device, and at the same time we read the resource for pci_dev in the pci_read_bases, we have res->name = pci_name(pci_dev); pci_name is calling dev_name. later via acpi_pci_root_driver.ops.start (aka acpi_pci_root_start) ==> pci_bus_add_device to add all pci_dev in kobj tree. pci_bus_add_device will call device_add. actually in device_add /* first, register with generic layer. */ error = kobject_add(&dev->kobj, dev->kobj.parent, "%s", dev_name(dev)); if (error) goto Error; will get one new name for that kobj, old name is freed. [Impact: fix corrupted names in /proc/iomem ] Signed-off-by: Yinghai Lu Signed-off-by: Linus Torvalds --- drivers/base/core.c | 3 ++- lib/kobject.c | 3 +++ 2 files changed, 5 insertions(+), 1 deletion(-) (limited to 'lib') diff --git a/drivers/base/core.c b/drivers/base/core.c index d230ff4b3ee..4aa527b8a91 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -891,7 +891,8 @@ int device_add(struct device *dev) set_dev_node(dev, dev_to_node(parent)); /* first, register with generic layer. */ - error = kobject_add(&dev->kobj, dev->kobj.parent, "%s", dev_name(dev)); + /* we require the name to be set before, and pass NULL */ + error = kobject_add(&dev->kobj, dev->kobj.parent, NULL); if (error) goto Error; diff --git a/lib/kobject.c b/lib/kobject.c index a6dec32f2dd..bacf6fe4f7a 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -218,6 +218,9 @@ int kobject_set_name_vargs(struct kobject *kobj, const char *fmt, const char *old_name = kobj->name; char *s; + if (kobj->name && !fmt) + return 0; + kobj->name = kvasprintf(GFP_KERNEL, fmt, vargs); if (!kobj->name) return -ENOMEM; -- cgit v1.2.3-70-g09d2 From 23c560a99d78bddf5c251bfa97bce19e4da4b3f3 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 15 Apr 2009 22:10:23 +0900 Subject: scatterlist: make sure sg_miter_next() doesn't return 0 sized mappings Impact: fix not-so-critical but annoying bug sg_miter_next() returns 0 sized mapping if there is an zero sized sg entry in the list or at the end of each iteration. As the users always check the ->length field, this bug shouldn't be critical other than causing unnecessary iteration. Fix it. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- lib/scatterlist.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'lib') diff --git a/lib/scatterlist.c b/lib/scatterlist.c index b7b449dafbe..a295e404e90 100644 --- a/lib/scatterlist.c +++ b/lib/scatterlist.c @@ -347,9 +347,12 @@ bool sg_miter_next(struct sg_mapping_iter *miter) sg_miter_stop(miter); /* get to the next sg if necessary. __offset is adjusted by stop */ - if (miter->__offset == miter->__sg->length && --miter->__nents) { - miter->__sg = sg_next(miter->__sg); - miter->__offset = 0; + while (miter->__offset == miter->__sg->length) { + if (--miter->__nents) { + miter->__sg = sg_next(miter->__sg); + miter->__offset = 0; + } else + return false; } /* map the next page */ -- cgit v1.2.3-70-g09d2 From 75ee034addc9ac3f6a38a9e6b30e9b54be15d4e5 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Thu, 23 Apr 2009 13:58:10 +0200 Subject: [S390] omit frame pointers on s390 when possible Always omit frame pointers on s390. They aren't too useful for the kernel since we have already the kernel stack backchain which allows us to walk the kernel stack. So eleminate the extra code for frame pointers. Only allow the extra code for the function tracer since the gcc compile options -pg and -fomit-frame-pointer are incompatible. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- lib/Kconfig.debug | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'lib') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index c6e854f215f..812c28207ba 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -440,7 +440,7 @@ config LOCKDEP bool depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT select STACKTRACE - select FRAME_POINTER if !X86 && !MIPS && !PPC && !ARM_UNWIND + select FRAME_POINTER if !X86 && !MIPS && !PPC && !ARM_UNWIND && !S390 select KALLSYMS select KALLSYMS_ALL @@ -620,7 +620,7 @@ config ARCH_WANT_FRAME_POINTERS config FRAME_POINTER bool "Compile the kernel with frame pointers" depends on DEBUG_KERNEL && \ - (CRIS || M68K || M68KNOMMU || FRV || UML || S390 || \ + (CRIS || M68K || M68KNOMMU || FRV || UML || \ AVR32 || SUPERH || BLACKFIN || MN10300) || \ ARCH_WANT_FRAME_POINTERS default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS @@ -809,13 +809,13 @@ config FAULT_INJECTION_STACKTRACE_FILTER depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT depends on !X86_64 select STACKTRACE - select FRAME_POINTER if !PPC + select FRAME_POINTER if !PPC && !S390 help Provide stacktrace filter for fault-injection capabilities config LATENCYTOP bool "Latency measuring infrastructure" - select FRAME_POINTER if !MIPS && !PPC + select FRAME_POINTER if !MIPS && !PPC && !S390 select KALLSYMS select KALLSYMS_ALL select STACKTRACE -- cgit v1.2.3-70-g09d2 From a5422a5111811401f7756345e4c237ff06cf6d1e Mon Sep 17 00:00:00 2001 From: Fred Isaman Date: Thu, 23 Apr 2009 16:40:32 +0300 Subject: lib: find_last_bit.o needed by a module only, move it from lib to obj Currently, although find_last_bit is EXPORTed, it is statically linked with the kernel and is referenced only under CONFIG_SMP. When CONFIG_SMP is undefined and find_last_bit is referenced only by modules, linking fails with: ERROR: "find_last_bit" [fs/nfs/nfs.ko] undefined! Cc: Rusty Russell Cc: Trond Myklebust Signed-off-by: Fred Isaman Signed-off-by: Benny Halevy Signed-off-by: Linus Torvalds --- lib/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/Makefile b/lib/Makefile index d6edd6753f4..33a40e40e3e 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -38,7 +38,7 @@ lib-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o lib-$(CONFIG_GENERIC_FIND_FIRST_BIT) += find_next_bit.o lib-$(CONFIG_GENERIC_FIND_NEXT_BIT) += find_next_bit.o -lib-$(CONFIG_GENERIC_FIND_LAST_BIT) += find_last_bit.o +obj-$(CONFIG_GENERIC_FIND_LAST_BIT) += find_last_bit.o obj-$(CONFIG_GENERIC_HWEIGHT) += hweight.o obj-$(CONFIG_LOCK_KERNEL) += kernel_lock.o obj-$(CONFIG_DEBUG_PREEMPT) += smp_processor_id.o -- cgit v1.2.3-70-g09d2 From 314eeac9e35d8b934dd7a09ed3a8e00d41977b84 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Fri, 24 Apr 2009 14:35:57 +0200 Subject: dma-debug: remove broken dma memory leak detection for 2.6.30 The feature needs some more work because the notfier which is used to check for pending allocations is called before the device drivers ->remove() function. Therefore this feature reports false positives. A real fix for this issue is to introduce a new notifier event which sent _after_ the driver has deinitialized itself. That will done for the next kernel version. [ Impact: reduce the scope of CONFIG_DMA_API_DEBUG=y checks ] Signed-off-by: Joerg Roedel Cc: iommu@lists.linux-foundation.org LKML-Reference: <1240576557-22442-1-git-send-email-joerg.roedel@amd.com> Signed-off-by: Ingo Molnar --- lib/dma-debug.c | 53 +---------------------------------------------------- 1 file changed, 1 insertion(+), 52 deletions(-) (limited to 'lib') diff --git a/lib/dma-debug.c b/lib/dma-debug.c index d3da7edc034..69da09a085a 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -400,60 +400,9 @@ out_err: return -ENOMEM; } -static int device_dma_allocations(struct device *dev) -{ - struct dma_debug_entry *entry; - unsigned long flags; - int count = 0, i; - - for (i = 0; i < HASH_SIZE; ++i) { - spin_lock_irqsave(&dma_entry_hash[i].lock, flags); - list_for_each_entry(entry, &dma_entry_hash[i].list, list) { - if (entry->dev == dev) - count += 1; - } - spin_unlock_irqrestore(&dma_entry_hash[i].lock, flags); - } - - return count; -} - -static int dma_debug_device_change(struct notifier_block *nb, - unsigned long action, void *data) -{ - struct device *dev = data; - int count; - - - switch (action) { - case BUS_NOTIFY_UNBIND_DRIVER: - count = device_dma_allocations(dev); - if (count == 0) - break; - err_printk(dev, NULL, "DMA-API: device driver has pending " - "DMA allocations while released from device " - "[count=%d]\n", count); - break; - default: - break; - } - - return 0; -} - void dma_debug_add_bus(struct bus_type *bus) { - struct notifier_block *nb; - - nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL); - if (nb == NULL) { - printk(KERN_ERR "dma_debug_add_bus: out of memory\n"); - return; - } - - nb->notifier_call = dma_debug_device_change; - - bus_register_notifier(bus, nb); + /* FIXME: register notifier */ } /* -- cgit v1.2.3-70-g09d2