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[PATCH v2 2/2] USB: ehci-s5p: add DMA burst support

by Jingoo Han

DMA burst support is added to improve performance in EHCI data transfer. The USB EHCI controller on Exynos SoCs can use INCR16, INCR8, and INCR4 mode. These modes of INSNREG00 register should be set in order to enable DMA burst transfer. This feature is also related to AHB spec. Signed-off-by: Jingoo Han <jg1.han(a)samsung.com> Cc: Sangwook Lee <sangwook.lee(a)linaro.org> --- v2: change the definition name from EHCI_ENA_xxx to EHCI_INSNREG00_ENA_xxx. drivers/usb/host/ehci-s5p.c | 7 +++++++ 1 files changed, 7 insertions(+), 0 deletions(-) diff --git a/drivers/usb/host/ehci-s5p.c b/drivers/usb/host/ehci-s5p.c index 293f741..b337f72 100644 --- a/drivers/usb/host/ehci-s5p.c +++ b/drivers/usb/host/ehci-s5p.c @@ -16,6 +16,7 @@ #include <linux/platform_device.h> #include <plat/ehci.h> #include <plat/usb-phy.h> +#include <mach/regs-usb-host.h> struct s5p_ehci_hcd { struct device *dev; @@ -128,6 +129,9 @@ static int __devinit s5p_ehci_probe(struct platform_device *pdev) ehci->regs = hcd->regs + HC_LENGTH(ehci, readl(&ehci->caps->hc_capbase)); + /* DMA burst Enable */ + writel(EHCI_INSNREG00_ENABLE_DMA_BURST, EHCI_INSNREG00(hcd->regs)); + dbg_hcs_params(ehci, "reset"); dbg_hcc_params(ehci, "reset"); @@ -234,6 +238,9 @@ static int s5p_ehci_resume(struct device *dev) if (pdata && pdata->phy_init) pdata->phy_init(pdev, S5P_USB_PHY_HOST); + /* DMA burst Enable */ + writel(EHCI_INSNREG00_ENABLE_DMA_BURST, EHCI_INSNREG00(hcd->regs)); + if (time_before(jiffies, ehci->next_statechange)) msleep(100); -- 1.7.1

13 years, 4 months

[PATCH 1/2] ARM: EXYNOS: Add USB HOST register definitions

by Jingoo Han

This patch adds USB HOST register definitions. The definition for EHCI INSNREG00 regiser and corresponding bit field definitions are added. Signed-off-by: Jingoo Han <jg1.han(a)samsung.com> --- arch/arm/mach-exynos/include/mach/regs-usb-host.h | 23 +++++++++++++++++++++ 1 files changed, 23 insertions(+), 0 deletions(-) create mode 100644 arch/arm/mach-exynos/include/mach/regs-usb-host.h diff --git a/arch/arm/mach-exynos/include/mach/regs-usb-host.h b/arch/arm/mach-exynos/include/mach/regs-usb-host.h new file mode 100644 index 0000000..1a60f27 --- /dev/null +++ b/arch/arm/mach-exynos/include/mach/regs-usb-host.h @@ -0,0 +1,23 @@ +/* + * Copyright (C) 2012 Samsung Electronics Co.Ltd + * http://www.samsung.com + * + * EXYNOS - USB HOST register definitions + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifndef __REGS_USB_HOST_H +#define __REGS_USB_HOST_H __FILE__ + +#define EHCI_INSNREG00(base) (base + 0x90) +#define EHCI_ENA_INCR16 (0x1 << 25) +#define EHCI_ENA_INCR8 (0x1 << 24) +#define EHCI_ENA_INCR4 (0x1 << 23) +#define EHCI_ENA_INCRX_ALIGN (0x1 << 22) +#define EHCI_ENABLE_DMA_INCR (EHCI_ENA_INCR16 | EHCI_ENA_INCR8| \ + EHCI_ENA_INCR4 | EHCI_ENA_INCRX_ALIGN) + +#endif /* __REGS_USB_HOST_H */ -- 1.7.1

13 years, 4 months

[PATCH] module: debugging check for runaway kthreads

by Dmitry Antipov

Debugging option CONFIG_MODULE_KTHREAD_CHECK provides a way to check whether all kernel threads created by the module and have used module code as a thread worker function are really exited when the module is unloaded. The following pseudo-code contains example of an error which is likely to be catched with this debugging check: static struct task_struct *tsk; static DECLARE_COMPLETION(done); static void *func(void *unused) { while (!kthread_should_stop()) real_work(); complete(&done); } static int __init modinit(void) { tsk = kthread_run(func, NULL, "func"); return IS_ERR(tsk) ? PTR_ERR(tsk) : 0; } static void __exit modexit(void) { wait_for_completion(&done); } Reviewed-by: Andrew Morton <akpm(a)linux-foundation.org> Signed-off-by: Dmitry Antipov <dmitry.antipov(a)linaro.org> --- include/linux/kthread.h | 3 ++ kernel/kthread.c | 38 +++++++++++++++++++++++++++++++++++ kernel/module.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++ lib/Kconfig.debug | 9 ++++++++ 4 files changed, 101 insertions(+), 0 deletions(-) diff --git a/include/linux/kthread.h b/include/linux/kthread.h index 0714b24..202fe14 100644 --- a/include/linux/kthread.h +++ b/include/linux/kthread.h @@ -13,6 +13,9 @@ struct task_struct *kthread_create_on_node(int (*threadfn)(void *data), #define kthread_create(threadfn, data, namefmt, arg...) \ kthread_create_on_node(threadfn, data, -1, namefmt, ##arg) +#ifdef CONFIG_MODULE_KTHREAD_CHECK +unsigned long get_kthread_func(struct task_struct *tsk); +#endif /** * kthread_run - create and wake a thread. diff --git a/kernel/kthread.c b/kernel/kthread.c index 3d3de63..e6f7977 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -38,6 +38,13 @@ struct kthread_create_info struct kthread { int should_stop; +#ifdef CONFIG_MODULE_KTHREAD_CHECK + /* + * Kthread worker function, i.e. first argument + * passed to kthread_create() and kthread_run(). + */ + void *fn; +#endif void *data; struct completion exited; }; @@ -45,6 +52,32 @@ struct kthread { #define to_kthread(tsk) \ container_of((tsk)->vfork_done, struct kthread, exited) +#ifdef CONFIG_MODULE_KTHREAD_CHECK + +/* + * Assuming the task is a kernel thread, try to get it's worker + * function, i.e. the first argument of kthread_create()/kthread_run(). + */ +unsigned long get_kthread_func(struct task_struct *tsk) +{ + struct kthread *kt; + unsigned long addr; + + get_task_struct(tsk); + BUG_ON(!(tsk->flags & PF_KTHREAD)); + kt = to_kthread(tsk); + barrier(); + /* + * Note kt is valid only if vfork_done is initialized. + * See kthread() to check why it's so. + */ + addr = tsk->vfork_done ? (unsigned long)kt->fn : 0UL; + put_task_struct(tsk); + return addr; +} + +#endif /* CONFIG_MODULE_KTHREAD_CHECK */ + /** * kthread_should_stop - should this kthread return now? * @@ -106,8 +139,13 @@ static int kthread(void *_create) int ret; self.should_stop = 0; +#ifdef CONFIG_MODULE_KTHREAD_CHECK + /* Will be used by get_kthread_func(). */ + self.fn = threadfn; +#endif self.data = data; init_completion(&self.exited); + /* Setup self so to_kthread() macro may be used. */ current->vfork_done = &self.exited; /* OK, tell user we're spawned, wait for stop or wakeup */ diff --git a/kernel/module.c b/kernel/module.c index 2c93276..7ad8a03 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -45,6 +45,7 @@ #include <linux/string.h> #include <linux/mutex.h> #include <linux/rculist.h> +#include <linux/kthread.h> #include <asm/uaccess.h> #include <asm/cacheflush.h> #include <asm/mmu_context.h> @@ -223,6 +224,8 @@ extern const unsigned long __start___kcrctab_unused[]; extern const unsigned long __start___kcrctab_unused_gpl[]; #endif +static void check_kthreads(struct module *mod); + #ifndef CONFIG_MODVERSIONS #define symversion(base, idx) NULL #else @@ -831,6 +834,7 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user, blocking_notifier_call_chain(&module_notify_list, MODULE_STATE_GOING, mod); async_synchronize_full(); + check_kthreads(mod); /* Store the name of the last unloaded module for diagnostic purposes */ strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module)); @@ -3274,8 +3278,55 @@ int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *, } return 0; } + +#else /* not CONFIG_KALLSYMS */ + +static inline const char *get_ksymbol(struct module *mod, + unsigned long addr, + unsigned long *size, + unsigned long *offset) +{ + return "<unknown>"; +} + #endif /* CONFIG_KALLSYMS */ +#ifdef CONFIG_MODULE_KTHREAD_CHECK + +static void check_kthreads(struct module *mod) +{ + unsigned long flags; + struct task_struct *g, *p; + + read_lock_irqsave(&tasklist_lock, flags); + do_each_thread(g, p) { + const char *name; + unsigned long addr, offset, size; + + /* Note kthreadd is special. Other kthreads should + have their struct kthread on the stack until + do_exit() calls schedule() for the last time. */ + if (p->mm || p == kthreadd_task) + continue; + + addr = get_kthread_func(p); + if (__module_text_address(addr) == mod) { + name = get_ksymbol(mod, addr, &size, &offset); + printk(KERN_WARNING "kthread %p[%s:%d] running " + "0x%lx(%s) is still alive, fix module %s, " + "crash possible\n", p, p->comm, p->pid, + addr, name, mod->name); + } + } while_each_thread(g, p); + read_unlock_irqrestore(&tasklist_lock, flags); +} + +#else + +static void check_kthreads(struct module *mod) {} + +#endif /* CONFIG_MODULE_KTHREAD_CHECK */ + static char *module_flags(struct module *mod, char *buf) { int bx = 0; diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 8745ac7..f082a76 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1121,6 +1121,15 @@ config SYSCTL_SYSCALL_CHECK to properly maintain and use. This enables checks that help you to keep things correct. +config MODULE_KTHREAD_CHECK + bool "Check for runaway kernel threads at module unload" + depends on MODULE_UNLOAD && EXPERIMENTAL && DEBUG_KERNEL + help + This option allows you to check whether all kernel threads created + by the module and have used module code as a thread worker function + are really exited when the module is unloaded. This is mainly for + module developers. If insure, say N. + source mm/Kconfig.debug source kernel/trace/Kconfig -- 1.7.7.6

13 years, 4 months

[PATCH v6 0/9] Consolidate cpuidle functionality

by Robert Lee

This patch series moves various functionality duplicated in platform cpuidle drivers to the core cpuidle driver. Also, the platform irq disabling was removed as it appears that all calls into cpuidle_call_idle will have already called local_irq_disable(). NOTE to Maintainers: Platform code changes are not required due to patch 1/9 but please review and push these platform changes as possible to allow this consolidation to occur. Based on 3.3-rc5 plus recent exynos cpuidle patch (affect exynos cpuidle only): http://www.spinics.net/lists/linux-samsung-soc/msg09467.html v5 submission can be found here: http://www.spinics.net/lists/arm-kernel/msg161596.html Changes since v5: * Fixed mindless bug in CONFIG_ARCH_HAS_RELAX code in drivers/cpuidle/cpuidle.c * Removed inline from wrapper function (thanks Mike Turquette and Rob Herring) * Add zeroing out of last_residency if error value is returned (thanks Mike) * Made drivers/cpuidle/cpuidle.c more intelligently handle en_core_tk_irqen flag allowing removal of the if (en_core_tk_irqen) in cpuidle_idle_call (thanks Daniel Lezcano) * Moved CPUIDLE_ARM_WFI_STATE macro to arch/arm/include/asm/cpuidle.h (thanks Jean Pihet) * Cleaned up some comments and a stray change (thanks Jean) v4 submission can be found here: http://lists.infradead.org/pipermail/linux-arm-kernel/2012-January/082742.h… Changes since v4: * Added common cpu_do_idle function to core cpuidle * Added time keep irq en wrapper to core cpuidle * Removed pre/post enter * Re-added platforms that can use new common code. v3 submission can be found here: http://www.spinics.net/lists/arm-kernel/msg156751.html Changes since v3: * Removed drivers/cpuidle/common.c ** Removed the initialization helper functions ** Removed the wrapper used to consolidate time keeping and irq enable/disable * Add time keeping and local_irq_disable handling in cpuidle_call_idle(). * Made necessary modifications to a few platforms that required the most changes ** Note on omap3: changed structure of omap3_idle_drvdata and added per_next_state and per_saved_state vars to accomodate new framework. v2 submission can be found here: http://comments.gmane.org/gmane.linux.ports.arm.kernel/144199 Changes since v2: * Made various code organization and style changes as suggested in v1 review. * Removed at91 use of common code. A separate effort is underway to clean at91 code and the author has offered to convert to common interface as part of those changes (if this common interface is accepted in time). * Made platform cpuidle_driver objects __initdata and dynamically added one persistent instance of this object in common code. * Removed imx5 pm usage of gpc_dvfs clock as it is no longer needed after being enabled during clock initialization. * Re-organized patches. v1 submission can be found here: http://comments.gmane.org/gmane.linux.ports.arm.kernel/142791 Changes since v1: * Common interface moved to drivers/cpuidle and made non arch-specific. * Made various fixes and suggested additions to the common cpuidle code from v1 review. * Added callback for filling in driver_data field as needed. * Modified the various platforms with these changes. Robert Lee (9): cpuidle: Add common time keeping and irq enabling ARM: at91: Consolidate time keeping and irq enable ARM: exynos: Consolidate time keeping and irq enable ARM: kirkwood: Consolidate time keeping and irq enable ARM: davinci: Consolidate time keeping and irq enable ARM: omap: Consolidate OMAP3 time keeping and irq enable ARM: omap: Consolidate OMAP4 time keeping and irq enable ARM: shmobile: Consolidate time keeping and irq enable SH: shmobile: Consolidate time keeping and irq enable arch/arm/include/asm/cpuidle.h | 14 +++++ arch/arm/mach-at91/cpuidle.c | 67 +++++++++---------------- arch/arm/mach-davinci/cpuidle.c | 78 +++++++++++----------------- arch/arm/mach-exynos/cpuidle.c | 53 ++----------------- arch/arm/mach-kirkwood/cpuidle.c | 72 ++++++++------------------ arch/arm/mach-omap2/cpuidle34xx.c | 42 ++++++--------- arch/arm/mach-omap2/cpuidle44xx.c | 21 +------- arch/arm/mach-shmobile/cpuidle.c | 23 +------- arch/sh/kernel/cpu/shmobile/cpuidle.c | 10 +--- drivers/cpuidle/cpuidle.c | 90 ++++++++++++++++++++++++++------- include/linux/cpuidle.h | 13 +++++ 11 files changed, 207 insertions(+), 276 deletions(-) create mode 100644 arch/arm/include/asm/cpuidle.h

13 years, 4 months

Java jogl and jogamp acceleration

by Wookey

I'm not sure who needs to know about this - maybe you all do already, but Xerces Ranby showed me (at FOSDEM) some cool stuff with jogl giving java stuff access to OPenGL ES hardware acceleration. His demo on an AC100 sped java games up by a factor of lots so instead of visibly slow screen redraws you got a useful frame rate of 15fps or so, turning them from useless to playable. Blog post here with destructions and links: http://labb.zafena.se/?p=532 Compatibility matrix here shows that it works with Tegra2 in AC100, and trimslice, SGX540 in panda and SGX530 in N9. It seems to be a fairly trivial matter of telling openjdk to use jogl and then 'stuff goes fast'. If we aren't doing this already in our images we probably should be. Just posting so that whoever worries about graphics and java and stuff knows about this. Wookey -- Principal hats: Linaro, Emdebian, Wookware, Balloonboard, ARM http://wookware.org/

13 years, 4 months

Rant about binary blobs on #img

by Zach Pfeffer

Come one and all to change the world.... -- Zach Pfeffer Android Platform Team Lead, Linaro Platform Teams Linaro.org | Open source software for ARM SoCs Follow Linaro: http://www.facebook.com/pages/Linaro http://twitter.com/#!/linaroorg - http://www.linaro.org/linaro-blog

13 years, 4 months

Is LatencyTOP dead?

by Dmitry Antipov

Are there any efforts going on LatencyTOP? Is it dead? Is it canceled in favor of another similar project? Dmitry

13 years, 4 months

Sample big.LITTLE model boot images

by Dave Martin

Hi all, I've added some detailed info on the wiki about how to go about building bootable images for the big.LITTLE components, here: https://wiki.linaro.org/Internal/Projects/Big.Little.Switcher/ARMFastModels… For the benefit of anyone who can't see that page, I've also pasted it here -- if anyone knows a better place to post this stuff, please let me know! Note that although the instructions give details of how to build a filesystem image, there is essentially nothing b.L or model-specific there -- it just serves as background for explaining how to work around some issues which you may encounter. These images are not supposed to present a fully working big.LITTLE system -- they are there to help people understand how booting works, where the sources are and how to work with the model. Note also that the bootwrapper will change soon (when I get there) to support loading of the kernel, initramfs from the host filesystem using semihosting, just like the kvm bootwrapper, but this isn't implemented for now. Cheers ---Dave == Filesystem == We need to create an SD card image with a filesystem on it, with the rootfs partition matching the bootargs set previously. The following example generates a suitable image using developer. The hardware pack is largely irrelevant because we're not getting the kernel, modules, bootloader or command-line from there -- but it keeps l-m-c happy. {{{ $ wget http://releases.linaro.org/12.02/ubuntu/oneiric-images/developer/linaro-o-d… $ wget http://releases.linaro.org/12.02/ubuntu/oneiric-images/developer/hwpack_lin… }}} Note that the ARM fast model's MMC interface emulation is currently limited to 2G. Make the image a bit smaller than that to be on the safe side: {{{ $ sudo linaro-media-create --dev vexpress --image_file mmc.bin --image_size 2000M --hwpack hwpack_linaro-lt-vexpress-a9_20120221-1_armel_suupported.tar.gz --binary linaro-o-developer-tar-20120221-0.tar.gz }}} After generating the filesystem, you probably want to customize it: * Disable address layout randomization (mitigates a memory consumption issue with the model, but not so important on host machines with >4GB of RAM): {{{ echo sys.kernel.randomize_va_space = 0 >>etc/sysctl.conf }}} * Disable DHCP for the network (otherwise boot will stall): {{{ sed -i '/auto.*eth0/d; s/^$iface.*eth0.*$dhcp/\1manual/' etc/network/interfaces }}} * Edit fstab to put the real device name into /etc/fstab in place of UUID=<uuid>. This may not be necessary (mountall was getting confused, but that may have been caused by not having an initramfs). Finally, extract the initramfs image (whatever /initrd.img in the filesystem image points to). == Kernel, switcher and bootwrapper == Clone the big.LITTLE switcher: {{{ $ git clone --branch gnu-build git://git.linaro.org/people/dmart/arm-virt-bl.git }}} Clone the kernel to run on the model. (Eventually we shouldn't need a special tree for this. There are a few model-specific tweaks in this tree, but nothing big.LITTLE-specific yet.) {{{ $ git clone --branch arm/vexpressdt-rtsm git://git.linaro.org/people/dmart/linux-2.6-arm.git }}} Now build the kernel: {{{ $ cd linux-2.6-arm/ $ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- vexpress_rtsm_defconfig $ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- zImage dtbs }}} The bootwrapper doesn't support device tree yet, so for now append a suitable device tree blob to the zImage. This should match the model you intend to run on: {{{ $ cat arch/arm/boot/zImage arch/arm/boot/vexprress-v2p-ca15x4-rtsm.dtb >../zBlob }}} Now, build the bootwrapper using the kernel you just built: {{{ $ cd ../arm-virt-bl/bootwrapper }}} Configure some things: In Makefile, add the following argument to BOOTARGS: {{{ root=/dev/mmcblk0p2 }}} Due to current bugginess introduced by the ARM->GNU toolchain migration, the switcher is not currently stable. For now, we turn off autonomous asynchronous switching so that we can see the system booting: In big-little/Makefile, add change the line {{{ ASYNC ?= TRUE }}} to {{{ ASYNC ?= FALSE }}} Plug in the kernel and initramfs images from the previous steps: {{{ $ : >payload/fsimg $ cp ../../zBlob payload/kernel $ cp initrd.img payload/fsimg }}} ... and build: {{{ $ make [...] LD img.axf }}} img.axf is the boot payload which is needed to start the model. It contains the big.LITTLE switcher code and the kernel, along with a minimal bootloader. == Running == OK, so now we have: * A boot image containing the switcher and kernel: img.axf * A filesystem MMC card image: mmc.bin * A model binary Sample payload images can be found in http://people.linaro.org/~dmart/bl-images/model-images-20120228.tar.bz2 Run like this: {{{ $ ./RTSM_VE_Cortex-A15x4-A7x4 -C motherboard.mmc.p_mmc_file=mmc.bin -a coretile.cluster0.*=img.axf }}} This should be enough to boot to a prompt on the simulated UART. Beware though -- it can take up to 10 minutes or so to get there, depending on your machine.

13 years, 4 months

[PATCH 2/2] USB: ehci-s5p: add DMA burst support

by Jingoo Han

DMA burst support is added to improve performance in EHCI data transfer. The USB EHCI controller on Exynos SoCs can use INCR16, INCR8, and INCR4 mode. These modes of INSNREG00 register should be set in order to enable DMA burst transfer. This feature is also related to AHB spec. Signed-off-by: Jingoo Han <jg1.han(a)samsung.com> Cc: Sangwook Lee <sangwook.lee(a)linaro.org> --- drivers/usb/host/ehci-s5p.c | 7 +++++++ 1 files changed, 7 insertions(+), 0 deletions(-) diff --git a/drivers/usb/host/ehci-s5p.c b/drivers/usb/host/ehci-s5p.c index 293f741..465861b 100644 --- a/drivers/usb/host/ehci-s5p.c +++ b/drivers/usb/host/ehci-s5p.c @@ -16,6 +16,7 @@ #include <linux/platform_device.h> #include <plat/ehci.h> #include <plat/usb-phy.h> +#include <mach/regs-usb-host.h> struct s5p_ehci_hcd { struct device *dev; @@ -128,6 +129,9 @@ static int __devinit s5p_ehci_probe(struct platform_device *pdev) ehci->regs = hcd->regs + HC_LENGTH(ehci, readl(&ehci->caps->hc_capbase)); + /* DMA burst Enable */ + writel(EHCI_ENABLE_DMA_INCR, EHCI_INSNREG00(hcd->regs)); + dbg_hcs_params(ehci, "reset"); dbg_hcc_params(ehci, "reset"); @@ -234,6 +238,9 @@ static int s5p_ehci_resume(struct device *dev) if (pdata && pdata->phy_init) pdata->phy_init(pdev, S5P_USB_PHY_HOST); + /* DMA burst Enable */ + writel(EHCI_ENABLE_DMA_INCR, EHCI_INSNREG00(hcd->regs)); + if (time_before(jiffies, ehci->next_statechange)) msleep(100); -- 1.7.1

13 years, 4 months

[RFC PATCH] module: debugging check for runaway kthreads

by Dmitry Antipov

Debugging option CONFIG_MODULE_KTHREAD_CHECK provides a way to check whether all kernel threads created by the module and have used module code as a thread worker function are really exited when the module is unloaded. The following pseudo-code contains example of an error which is likely to be catched with this debugging check: static struct task_struct *tsk; static DECLARE_COMPLETION(done); static void *func(void *unused) { while (!kthread_should_stop()) real_work(); complete(&done); } static int __init modinit(void) { tsk = kthread_run(func, NULL, "func"); return IS_ERR(tsk) ? PTR_ERR(tsk) : 0; } static void __exit modexit(void) { wait_for_completion(&done); } Signed-off-by: Dmitry Antipov <dmitry.antipov(a)linaro.org> --- include/linux/kthread.h | 5 +++++ init/Kconfig | 9 +++++++++ kernel/kthread.c | 24 ++++++++++++++++++++++++ kernel/module.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 83 insertions(+), 0 deletions(-) diff --git a/include/linux/kthread.h b/include/linux/kthread.h index 0714b24..33897c3 100644 --- a/include/linux/kthread.h +++ b/include/linux/kthread.h @@ -13,6 +13,11 @@ struct task_struct *kthread_create_on_node(int (*threadfn)(void *data), #define kthread_create(threadfn, data, namefmt, arg...) \ kthread_create_on_node(threadfn, data, -1, namefmt, ##arg) +#ifdef CONFIG_MODULE_KTHREAD_CHECK +unsigned long get_kthread_func(struct task_struct *tsk); +#else +#define get_kthread_func(tsk, addr, mod) (0) +#endif /** * kthread_run - create and wake a thread. diff --git a/init/Kconfig b/init/Kconfig index 3f42cd6..fa7c6e0 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1397,6 +1397,15 @@ config MODULE_FORCE_UNLOAD rmmod). This is mainly for kernel developers and desperate users. If unsure, say N. +config MODULE_KTHREAD_CHECK + bool "Check for runaway kernel threads at module unload" + depends on MODULE_UNLOAD && EXPERIMENTAL && DEBUG_KERNEL + help + This option allows you to check whether all kernel threads created + by the module and have used module code as a thread worker function + are really exited when the module is unloaded. This is mainly for + module developers. If insure, say N. + config MODVERSIONS bool "Module versioning support" help diff --git a/kernel/kthread.c b/kernel/kthread.c index 3d3de63..5c53817 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -38,6 +38,9 @@ struct kthread_create_info struct kthread { int should_stop; +#ifdef CONFIG_MODULE_KTHREAD_CHECK + void *fn; +#endif void *data; struct completion exited; }; @@ -45,6 +48,24 @@ struct kthread { #define to_kthread(tsk) \ container_of((tsk)->vfork_done, struct kthread, exited) +#ifdef CONFIG_MODULE_KTHREAD_CHECK + +unsigned long get_kthread_func(struct task_struct *tsk) +{ + struct kthread *kt; + unsigned long addr; + + get_task_struct(tsk); + BUG_ON(!(tsk->flags & PF_KTHREAD)); + kt = to_kthread(tsk); + barrier(); + addr = tsk->vfork_done ? (unsigned long)kt->fn : 0UL; + put_task_struct(tsk); + return addr; +} + +#endif /* CONFIG_MODULE_KTHREAD_CHECK */ + /** * kthread_should_stop - should this kthread return now? * @@ -106,6 +127,9 @@ static int kthread(void *_create) int ret; self.should_stop = 0; +#ifdef CONFIG_MODULE_KTHREAD_CHECK + self.fn = threadfn; +#endif self.data = data; init_completion(&self.exited); current->vfork_done = &self.exited; diff --git a/kernel/module.c b/kernel/module.c index 2c93276..fe6637b 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -45,6 +45,7 @@ #include <linux/string.h> #include <linux/mutex.h> #include <linux/rculist.h> +#include <linux/kthread.h> #include <asm/uaccess.h> #include <asm/cacheflush.h> #include <asm/mmu_context.h> @@ -764,6 +765,49 @@ static void wait_for_zero_refcount(struct module *mod) mutex_lock(&module_mutex); } +#ifdef CONFIG_KALLSYMS +static const char *get_ksymbol(struct module *mod, unsigned long addr, + unsigned long *size, unsigned long *offset); +#else +#define get_ksymbol(mod, addr, size, offset) NULL +#endif + +#ifdef CONFIG_MODULE_KTHREAD_CHECK + +static void check_kthreads(struct module *mod) +{ + unsigned long flags; + struct task_struct *g, *p; + + read_lock_irqsave(&tasklist_lock, flags); + do_each_thread(g, p) { + const char *name; + unsigned long addr, offset, size; + + /* Note kthreadd is special. Other kthreads should + have their 'struct kthread' on the stack until + do_exit() calls schedule() for the last time. */ + if (p->mm || p == kthreadd_task) + continue; + + addr = get_kthread_func(p); + if (__module_text_address(addr) == mod) { + name = get_ksymbol(mod, addr, &size, &offset); + printk(KERN_WARNING "kthread %p[%s:%d] running " + "0x%lx(%s) is still alive, fix module %s, " + "crash possible\n", p, p->comm, p->pid, addr, + (name ? name : "<unknown>"), mod->name); + } + } while_each_thread(g, p); + read_unlock_irqrestore(&tasklist_lock, flags); +} + +#else + +#define check_kthreads(mod) do { } while (0) + +#endif /* CONFIG_MODULE_KTHREAD_CHECK */ + SYSCALL_DEFINE2(delete_module, const char __user *, name_user, unsigned int, flags) { @@ -831,6 +875,7 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user, blocking_notifier_call_chain(&module_notify_list, MODULE_STATE_GOING, mod); async_synchronize_full(); + check_kthreads(mod); /* Store the name of the last unloaded module for diagnostic purposes */ strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module)); -- 1.7.7.6

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