From e162b39a368f0401e41b558f430c354d12a85b37 Mon Sep 17 00:00:00 2001 From: Mandeep Singh Baines Date: Thu, 15 Jan 2009 11:08:40 -0800 Subject: softlockup: decouple hung tasks check from softlockup detection Decoupling allows: * hung tasks check to happen at very low priority * hung tasks check and softlockup to be enabled/disabled independently at compile and/or run-time * individual panic settings to be enabled disabled independently at compile and/or run-time * softlockup threshold to be reduced without increasing hung tasks poll frequency (hung task check is expensive relative to softlock watchdog) * hung task check to be zero over-head when disabled at run-time Signed-off-by: Mandeep Singh Baines Signed-off-by: Ingo Molnar --- lib/Kconfig.debug | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) (limited to 'lib/Kconfig.debug') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 4c9ae6085c75..883ecea22f37 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -186,6 +186,44 @@ config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC default 1 if BOOTPARAM_SOFTLOCKUP_PANIC +config DETECT_HUNG_TASK + bool "Detect Hung Tasks" + depends on DEBUG_KERNEL + default y + help + Say Y here to enable the kernel to detect "hung tasks", + which are bugs that cause the task to be stuck in + uninterruptible "D" state indefinitiley. + + When a hung task is detected, the kernel will print the + current stack trace (which you should report), but the + task will stay in uninterruptible state. If lockdep is + enabled then all held locks will also be reported. This + feature has negligible overhead. + +config BOOTPARAM_HUNG_TASK_PANIC + bool "Panic (Reboot) On Hung Tasks" + depends on DETECT_HUNG_TASK + help + Say Y here to enable the kernel to panic on "hung tasks", + which are bugs that cause the kernel to leave a task stuck + in uninterruptible "D" state. + + The panic can be used in combination with panic_timeout, + to cause the system to reboot automatically after a + hung task has been detected. This feature is useful for + high-availability systems that have uptime guarantees and + where a hung tasks must be resolved ASAP. + + Say N if unsure. + +config BOOTPARAM_HUNG_TASK_PANIC_VALUE + int + depends on DETECT_HUNG_TASK + range 0 1 + default 0 if !BOOTPARAM_HUNG_TASK_PANIC + default 1 if BOOTPARAM_HUNG_TASK_PANIC + config SCHED_DEBUG bool "Collect scheduler debugging info" depends on DEBUG_KERNEL && PROC_FS -- cgit v1.3-14-g43fede From adf8b37bafc1495393201a2ae4235846371870d0 Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Thu, 12 Feb 2009 13:56:34 +0100 Subject: [ARM] 5386/2: unwind: Add Makefile and Kconfig entries for ARM stack unwinding This patch also makes the frame pointer default to y only if !ARM_UNWIND. LOCKDEP no longer selects FRAME_POINTER if ARM_UNWIND is enabled. Signed-off-by: Catalin Marinas Signed-off-by: Russell King --- arch/arm/Kconfig.debug | 21 ++++++++++++++++----- arch/arm/Makefile | 4 ++++ arch/arm/kernel/Makefile | 1 + lib/Kconfig.debug | 2 +- 4 files changed, 22 insertions(+), 6 deletions(-) (limited to 'lib/Kconfig.debug') diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug index 192ee01a9ba2..35f8db35f442 100644 --- a/arch/arm/Kconfig.debug +++ b/arch/arm/Kconfig.debug @@ -2,18 +2,29 @@ menu "Kernel hacking" source "lib/Kconfig.debug" -# RMK wants arm kernels compiled with frame pointers so hardwire this to y. +# RMK wants arm kernels compiled with frame pointers or stack unwinding. # If you know what you are doing and are willing to live without stack # traces, you can get a slightly smaller kernel by setting this option to # n, but then RMK will have to kill you ;). config FRAME_POINTER bool - default y + default y if !ARM_UNWIND help If you say N here, the resulting kernel will be slightly smaller and - faster. However, when a problem occurs with the kernel, the - information that is reported is severely limited. Most people - should say Y here. + faster. However, if neither FRAME_POINTER nor ARM_UNWIND are enabled, + when a problem occurs with the kernel, the information that is + reported is severely limited. + +config ARM_UNWIND + bool "Enable stack unwinding support" + depends on AEABI && EXPERIMENTAL + default y + help + This option enables stack unwinding support in the kernel + using the information automatically generated by the + compiler. The resulting kernel image is slightly bigger but + the performance is not affected. Currently, this feature + only works with EABI compilers. If unsure say Y. config DEBUG_USER bool "Verbose user fault messages" diff --git a/arch/arm/Makefile b/arch/arm/Makefile index 24e0f0187697..e7ef876e574b 100644 --- a/arch/arm/Makefile +++ b/arch/arm/Makefile @@ -85,6 +85,10 @@ else CFLAGS_ABI :=$(call cc-option,-mapcs-32,-mabi=apcs-gnu) $(call cc-option,-mno-thumb-interwork,) endif +ifeq ($(CONFIG_ARM_UNWIND),y) +CFLAGS_ABI +=-funwind-tables +endif + # Need -Uarm for gcc < 3.x KBUILD_CFLAGS +=$(CFLAGS_ABI) $(arch-y) $(tune-y) $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,)) -msoft-float -Uarm KBUILD_AFLAGS +=$(CFLAGS_ABI) $(arch-y) $(tune-y) -msoft-float diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index 4305345987d3..ca60d335e8fa 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -29,6 +29,7 @@ obj-$(CONFIG_ATAGS_PROC) += atags.o obj-$(CONFIG_OABI_COMPAT) += sys_oabi-compat.o obj-$(CONFIG_ARM_THUMBEE) += thumbee.o obj-$(CONFIG_KGDB) += kgdb.o +obj-$(CONFIG_ARM_UNWIND) += unwind.o obj-$(CONFIG_CRUNCH) += crunch.o crunch-bits.o AFLAGS_crunch-bits.o := -Wa,-mcpu=ep9312 diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 29044f500269..08275a5aa00e 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -402,7 +402,7 @@ config LOCKDEP bool depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT select STACKTRACE - select FRAME_POINTER if !X86 && !MIPS && !PPC + select FRAME_POINTER if !X86 && !MIPS && !PPC && !ARM_UNWIND select KALLSYMS select KALLSYMS_ALL -- cgit v1.3-14-g43fede From 5ee00bd4691e7364bb7b62e2068d473cd5cb9320 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Fri, 9 Jan 2009 12:14:24 +0100 Subject: dma-debug: add Kconfig entry Impact: add a Kconfig entry for DMA-API debugging Signed-off-by: Joerg Roedel --- arch/Kconfig | 2 ++ lib/Kconfig.debug | 11 +++++++++++ 2 files changed, 13 insertions(+) (limited to 'lib/Kconfig.debug') diff --git a/arch/Kconfig b/arch/Kconfig index 550dab22daa1..830c16a2b801 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -106,3 +106,5 @@ config HAVE_CLK The calls support software clock gating and thus are a key power management tool on many systems. +config HAVE_DMA_API_DEBUG + bool diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 1bcf9cd4baa0..d9cbada7e2f8 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -902,6 +902,17 @@ config DYNAMIC_PRINTK_DEBUG debugging for all modules. This mode can be turned off via the above disable command. +config DMA_API_DEBUG + bool "Enable debugging of DMA-API usage" + depends on HAVE_DMA_API_DEBUG + help + Enable this option to debug the use of the DMA API by device drivers. + With this option you will be able to detect common bugs in device + drivers like double-freeing of DMA mappings or freeing mappings that + were never allocated. + This option causes a performance degredation. Use only if you want + to debug device drivers. If unsure, say N. + source "samples/Kconfig" source "lib/Kconfig.kgdb" -- cgit v1.3-14-g43fede From e9d376f0fa66bd630fe27403669c6ae6c22a868f Mon Sep 17 00:00:00 2001 From: Jason Baron Date: Thu, 5 Feb 2009 11:51:38 -0500 Subject: dynamic debug: combine dprintk and dynamic printk This patch combines Greg Bank's dprintk() work with the existing dynamic printk patchset, we are now calling it 'dynamic debug'. The new feature of this patchset is a richer /debugfs control file interface, (an example output from my system is at the bottom), which allows fined grained control over the the debug output. The output can be controlled by function, file, module, format string, and line number. for example, enabled all debug messages in module 'nf_conntrack': echo -n 'module nf_conntrack +p' > /mnt/debugfs/dynamic_debug/control to disable them: echo -n 'module nf_conntrack -p' > /mnt/debugfs/dynamic_debug/control A further explanation can be found in the documentation patch. Signed-off-by: Greg Banks Signed-off-by: Jason Baron Signed-off-by: Greg Kroah-Hartman --- Documentation/kernel-parameters.txt | 5 - include/asm-generic/vmlinux.lds.h | 15 +- include/linux/device.h | 2 +- include/linux/dynamic_debug.h | 88 +++++ include/linux/dynamic_printk.h | 93 ----- include/linux/kernel.h | 4 +- kernel/module.c | 25 +- lib/Kconfig.debug | 2 +- lib/Makefile | 2 +- lib/dynamic_debug.c | 756 ++++++++++++++++++++++++++++++++++++ lib/dynamic_printk.c | 414 -------------------- net/netfilter/nf_conntrack_pptp.c | 2 +- scripts/Makefile.lib | 2 +- 13 files changed, 867 insertions(+), 543 deletions(-) create mode 100644 include/linux/dynamic_debug.h delete mode 100644 include/linux/dynamic_printk.h create mode 100644 lib/dynamic_debug.c delete mode 100644 lib/dynamic_printk.c (limited to 'lib/Kconfig.debug') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 54f21a5c262b..3a1aa8a4affc 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1816,11 +1816,6 @@ and is between 256 and 4096 characters. It is defined in the file autoconfiguration. Ranges are in pairs (memory base and size). - dynamic_printk Enables pr_debug()/dev_dbg() calls if - CONFIG_DYNAMIC_PRINTK_DEBUG has been enabled. - These can also be switched on/off via - /dynamic_printk/modules - print-fatal-signals= [KNL] debug: print fatal signals print-fatal-signals=1: print segfault info to diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index c61fab1dd2f8..aca40b93bd28 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -80,6 +80,11 @@ VMLINUX_SYMBOL(__start___tracepoints) = .; \ *(__tracepoints) \ VMLINUX_SYMBOL(__stop___tracepoints) = .; \ + /* implement dynamic printk debug */ \ + . = ALIGN(8); \ + VMLINUX_SYMBOL(__start___verbose) = .; \ + *(__verbose) \ + VMLINUX_SYMBOL(__stop___verbose) = .; \ LIKELY_PROFILE() \ BRANCH_PROFILE() @@ -309,15 +314,7 @@ CPU_DISCARD(init.data) \ CPU_DISCARD(init.rodata) \ MEM_DISCARD(init.data) \ - MEM_DISCARD(init.rodata) \ - /* implement dynamic printk debug */ \ - VMLINUX_SYMBOL(__start___verbose_strings) = .; \ - *(__verbose_strings) \ - VMLINUX_SYMBOL(__stop___verbose_strings) = .; \ - . = ALIGN(8); \ - VMLINUX_SYMBOL(__start___verbose) = .; \ - *(__verbose) \ - VMLINUX_SYMBOL(__stop___verbose) = .; + MEM_DISCARD(init.rodata) #define INIT_TEXT \ *(.init.text) \ diff --git a/include/linux/device.h b/include/linux/device.h index f98d0cfb4f81..2918c0e8fdfd 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -582,7 +582,7 @@ extern const char *dev_driver_string(const struct device *dev); #if defined(DEBUG) #define dev_dbg(dev, format, arg...) \ dev_printk(KERN_DEBUG , dev , format , ## arg) -#elif defined(CONFIG_DYNAMIC_PRINTK_DEBUG) +#elif defined(CONFIG_DYNAMIC_DEBUG) #define dev_dbg(dev, format, ...) do { \ dynamic_dev_dbg(dev, format, ##__VA_ARGS__); \ } while (0) diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h new file mode 100644 index 000000000000..07781aaa1164 --- /dev/null +++ b/include/linux/dynamic_debug.h @@ -0,0 +1,88 @@ +#ifndef _DYNAMIC_DEBUG_H +#define _DYNAMIC_DEBUG_H + +/* dynamic_printk_enabled, and dynamic_printk_enabled2 are bitmasks in which + * bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They + * use independent hash functions, to reduce the chance of false positives. + */ +extern long long dynamic_debug_enabled; +extern long long dynamic_debug_enabled2; + +/* + * An instance of this structure is created in a special + * ELF section at every dynamic debug callsite. At runtime, + * the special section is treated as an array of these. + */ +struct _ddebug { + /* + * These fields are used to drive the user interface + * for selecting and displaying debug callsites. + */ + const char *modname; + const char *function; + const char *filename; + const char *format; + char primary_hash; + char secondary_hash; + unsigned int lineno:24; + /* + * The flags field controls the behaviour at the callsite. + * The bits here are changed dynamically when the user + * writes commands to /dynamic_debug/ddebug + */ +#define _DPRINTK_FLAGS_PRINT (1<<0) /* printk() a message using the format */ +#define _DPRINTK_FLAGS_DEFAULT 0 + unsigned int flags:8; +} __attribute__((aligned(8))); + + +int ddebug_add_module(struct _ddebug *tab, unsigned int n, + const char *modname); + +#if defined(CONFIG_DYNAMIC_DEBUG) +extern int ddebug_remove_module(char *mod_name); + +#define __dynamic_dbg_enabled(dd) ({ \ + int __ret = 0; \ + if (unlikely((dynamic_debug_enabled & (1LL << DEBUG_HASH)) && \ + (dynamic_debug_enabled2 & (1LL << DEBUG_HASH2)))) \ + if (unlikely(dd.flags)) \ + __ret = 1; \ + __ret; }) + +#define dynamic_pr_debug(fmt, ...) do { \ + static struct _ddebug descriptor \ + __used \ + __attribute__((section("__verbose"), aligned(8))) = \ + { KBUILD_MODNAME, __func__, __FILE__, fmt, DEBUG_HASH, \ + DEBUG_HASH2, __LINE__, _DPRINTK_FLAGS_DEFAULT }; \ + if (__dynamic_dbg_enabled(descriptor)) \ + printk(KERN_DEBUG KBUILD_MODNAME ":" fmt, \ + ##__VA_ARGS__); \ + } while (0) + + +#define dynamic_dev_dbg(dev, fmt, ...) do { \ + static struct _ddebug descriptor \ + __used \ + __attribute__((section("__verbose"), aligned(8))) = \ + { KBUILD_MODNAME, __func__, __FILE__, fmt, DEBUG_HASH, \ + DEBUG_HASH2, __LINE__, _DPRINTK_FLAGS_DEFAULT }; \ + if (__dynamic_dbg_enabled(descriptor)) \ + dev_printk(KERN_DEBUG, dev, \ + KBUILD_MODNAME ": " fmt, \ + ##__VA_ARGS__); \ + } while (0) + +#else + +static inline int ddebug_remove_module(char *mod) +{ + return 0; +} + +#define dynamic_pr_debug(fmt, ...) do { } while (0) +#define dynamic_dev_dbg(dev, format, ...) do { } while (0) +#endif + +#endif diff --git a/include/linux/dynamic_printk.h b/include/linux/dynamic_printk.h deleted file mode 100644 index 2d528d009074..000000000000 --- a/include/linux/dynamic_printk.h +++ /dev/null @@ -1,93 +0,0 @@ -#ifndef _DYNAMIC_PRINTK_H -#define _DYNAMIC_PRINTK_H - -#define DYNAMIC_DEBUG_HASH_BITS 6 -#define DEBUG_HASH_TABLE_SIZE (1 << DYNAMIC_DEBUG_HASH_BITS) - -#define TYPE_BOOLEAN 1 - -#define DYNAMIC_ENABLED_ALL 0 -#define DYNAMIC_ENABLED_NONE 1 -#define DYNAMIC_ENABLED_SOME 2 - -extern int dynamic_enabled; - -/* dynamic_printk_enabled, and dynamic_printk_enabled2 are bitmasks in which - * bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They - * use independent hash functions, to reduce the chance of false positives. - */ -extern long long dynamic_printk_enabled; -extern long long dynamic_printk_enabled2; - -struct mod_debug { - char *modname; - char *logical_modname; - char *flag_names; - int type; - int hash; - int hash2; -} __attribute__((aligned(8))); - -int register_dynamic_debug_module(char *mod_name, int type, char *share_name, - char *flags, int hash, int hash2); - -#if defined(CONFIG_DYNAMIC_PRINTK_DEBUG) -extern int unregister_dynamic_debug_module(char *mod_name); -extern int __dynamic_dbg_enabled_helper(char *modname, int type, - int value, int hash); - -#define __dynamic_dbg_enabled(module, type, value, level, hash) ({ \ - int __ret = 0; \ - if (unlikely((dynamic_printk_enabled & (1LL << DEBUG_HASH)) && \ - (dynamic_printk_enabled2 & (1LL << DEBUG_HASH2)))) \ - __ret = __dynamic_dbg_enabled_helper(module, type, \ - value, hash);\ - __ret; }) - -#define dynamic_pr_debug(fmt, ...) do { \ - static char mod_name[] \ - __attribute__((section("__verbose_strings"))) \ - = KBUILD_MODNAME; \ - static struct mod_debug descriptor \ - __used \ - __attribute__((section("__verbose"), aligned(8))) = \ - { mod_name, mod_name, NULL, TYPE_BOOLEAN, DEBUG_HASH, DEBUG_HASH2 };\ - if (__dynamic_dbg_enabled(KBUILD_MODNAME, TYPE_BOOLEAN, \ - 0, 0, DEBUG_HASH)) \ - printk(KERN_DEBUG KBUILD_MODNAME ":" fmt, \ - ##__VA_ARGS__); \ - } while (0) - -#define dynamic_dev_dbg(dev, format, ...) do { \ - static char mod_name[] \ - __attribute__((section("__verbose_strings"))) \ - = KBUILD_MODNAME; \ - static struct mod_debug descriptor \ - __used \ - __attribute__((section("__verbose"), aligned(8))) = \ - { mod_name, mod_name, NULL, TYPE_BOOLEAN, DEBUG_HASH, DEBUG_HASH2 };\ - if (__dynamic_dbg_enabled(KBUILD_MODNAME, TYPE_BOOLEAN, \ - 0, 0, DEBUG_HASH)) \ - dev_printk(KERN_DEBUG, dev, \ - KBUILD_MODNAME ": " format, \ - ##__VA_ARGS__); \ - } while (0) - -#else - -static inline int unregister_dynamic_debug_module(const char *mod_name) -{ - return 0; -} -static inline int __dynamic_dbg_enabled_helper(char *modname, int type, - int value, int hash) -{ - return 0; -} - -#define __dynamic_dbg_enabled(module, type, value, level, hash) ({ 0; }) -#define dynamic_pr_debug(fmt, ...) do { } while (0) -#define dynamic_dev_dbg(dev, format, ...) do { } while (0) -#endif - -#endif diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 7fa371898e3e..b5496ecbec71 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -16,7 +16,7 @@ #include #include #include -#include +#include #include #include @@ -358,7 +358,7 @@ static inline char *pack_hex_byte(char *buf, u8 byte) #if defined(DEBUG) #define pr_debug(fmt, ...) \ printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__) -#elif defined(CONFIG_DYNAMIC_PRINTK_DEBUG) +#elif defined(CONFIG_DYNAMIC_DEBUG) #define pr_debug(fmt, ...) do { \ dynamic_pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \ } while (0) diff --git a/kernel/module.c b/kernel/module.c index 1196f5d11700..77672233387f 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -822,7 +822,7 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user, mutex_lock(&module_mutex); /* Store the name of the last unloaded module for diagnostic purposes */ strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module)); - unregister_dynamic_debug_module(mod->name); + ddebug_remove_module(mod->name); free_module(mod); out: @@ -1827,19 +1827,13 @@ static inline void add_kallsyms(struct module *mod, } #endif /* CONFIG_KALLSYMS */ -static void dynamic_printk_setup(struct mod_debug *debug, unsigned int num) +static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num) { -#ifdef CONFIG_DYNAMIC_PRINTK_DEBUG - unsigned int i; - - for (i = 0; i < num; i++) { - register_dynamic_debug_module(debug[i].modname, - debug[i].type, - debug[i].logical_modname, - debug[i].flag_names, - debug[i].hash, debug[i].hash2); - } -#endif /* CONFIG_DYNAMIC_PRINTK_DEBUG */ +#ifdef CONFIG_DYNAMIC_DEBUG + if (ddebug_add_module(debug, num, debug->modname)) + printk(KERN_ERR "dynamic debug error adding module: %s\n", + debug->modname); +#endif } static void *module_alloc_update_bounds(unsigned long size) @@ -2213,12 +2207,13 @@ static noinline struct module *load_module(void __user *umod, add_kallsyms(mod, sechdrs, symindex, strindex, secstrings); if (!mod->taints) { - struct mod_debug *debug; + struct _ddebug *debug; unsigned int num_debug; debug = section_objs(hdr, sechdrs, secstrings, "__verbose", sizeof(*debug), &num_debug); - dynamic_printk_setup(debug, num_debug); + if (debug) + dynamic_debug_setup(debug, num_debug); } /* sechdrs[0].sh_size is always zero */ diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 1bcf9cd4baa0..0dd1c04c7323 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -847,7 +847,7 @@ config BUILD_DOCSRC Say N if you are unsure. -config DYNAMIC_PRINTK_DEBUG +config DYNAMIC_DEBUG bool "Enable dynamic printk() call support" default n depends on PRINTK diff --git a/lib/Makefile b/lib/Makefile index 32b0e64ded27..8633d6be9d21 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -82,7 +82,7 @@ obj-$(CONFIG_HAVE_LMB) += lmb.o obj-$(CONFIG_HAVE_ARCH_TRACEHOOK) += syscall.o -obj-$(CONFIG_DYNAMIC_PRINTK_DEBUG) += dynamic_printk.o +obj-$(CONFIG_DYNAMIC_DEBUG) += dynamic_debug.o hostprogs-y := gen_crc32table clean-files := crc32table.h diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c new file mode 100644 index 000000000000..9e123ae326bc --- /dev/null +++ b/lib/dynamic_debug.c @@ -0,0 +1,756 @@ +/* + * lib/dynamic_debug.c + * + * make pr_debug()/dev_dbg() calls runtime configurable based upon their + * source module. + * + * Copyright (C) 2008 Jason Baron + * By Greg Banks + * Copyright (c) 2008 Silicon Graphics Inc. All Rights Reserved. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +extern struct _ddebug __start___verbose[]; +extern struct _ddebug __stop___verbose[]; + +/* dynamic_debug_enabled, and dynamic_debug_enabled2 are bitmasks in which + * bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They + * use independent hash functions, to reduce the chance of false positives. + */ +long long dynamic_debug_enabled; +EXPORT_SYMBOL_GPL(dynamic_debug_enabled); +long long dynamic_debug_enabled2; +EXPORT_SYMBOL_GPL(dynamic_debug_enabled2); + +struct ddebug_table { + struct list_head link; + char *mod_name; + unsigned int num_ddebugs; + unsigned int num_enabled; + struct _ddebug *ddebugs; +}; + +struct ddebug_query { + const char *filename; + const char *module; + const char *function; + const char *format; + unsigned int first_lineno, last_lineno; +}; + +struct ddebug_iter { + struct ddebug_table *table; + unsigned int idx; +}; + +static DEFINE_MUTEX(ddebug_lock); +static LIST_HEAD(ddebug_tables); +static int verbose = 0; + +/* Return the last part of a pathname */ +static inline const char *basename(const char *path) +{ + const char *tail = strrchr(path, '/'); + return tail ? tail+1 : path; +} + +/* format a string into buf[] which describes the _ddebug's flags */ +static char *ddebug_describe_flags(struct _ddebug *dp, char *buf, + size_t maxlen) +{ + char *p = buf; + + BUG_ON(maxlen < 4); + if (dp->flags & _DPRINTK_FLAGS_PRINT) + *p++ = 'p'; + if (p == buf) + *p++ = '-'; + *p = '\0'; + + return buf; +} + +/* + * must be called with ddebug_lock held + */ + +static int disabled_hash(char hash, bool first_table) +{ + struct ddebug_table *dt; + char table_hash_value; + + list_for_each_entry(dt, &ddebug_tables, link) { + if (first_table) + table_hash_value = dt->ddebugs->primary_hash; + else + table_hash_value = dt->ddebugs->secondary_hash; + if (dt->num_enabled && (hash == table_hash_value)) + return 0; + } + return 1; +} + +/* + * Search the tables for _ddebug's which match the given + * `query' and apply the `flags' and `mask' to them. Tells + * the user which ddebug's were changed, or whether none + * were matched. + */ +static void ddebug_change(const struct ddebug_query *query, + unsigned int flags, unsigned int mask) +{ + int i; + struct ddebug_table *dt; + unsigned int newflags; + unsigned int nfound = 0; + char flagbuf[8]; + + /* search for matching ddebugs */ + mutex_lock(&ddebug_lock); + list_for_each_entry(dt, &ddebug_tables, link) { + + /* match against the module name */ + if (query->module != NULL && + strcmp(query->module, dt->mod_name)) + continue; + + for (i = 0 ; i < dt->num_ddebugs ; i++) { + struct _ddebug *dp = &dt->ddebugs[i]; + + /* match against the source filename */ + if (query->filename != NULL && + strcmp(query->filename, dp->filename) && + strcmp(query->filename, basename(dp->filename))) + continue; + + /* match against the function */ + if (query->function != NULL && + strcmp(query->function, dp->function)) + continue; + + /* match against the format */ + if (query->format != NULL && + strstr(dp->format, query->format) == NULL) + continue; + + /* match against the line number range */ + if (query->first_lineno && + dp->lineno < query->first_lineno) + continue; + if (query->last_lineno && + dp->lineno > query->last_lineno) + continue; + + nfound++; + + newflags = (dp->flags & mask) | flags; + if (newflags == dp->flags) + continue; + + if (!newflags) + dt->num_enabled--; + else if (!dp-flags) + dt->num_enabled++; + dp->flags = newflags; + if (newflags) { + dynamic_debug_enabled |= + (1LL << dp->primary_hash); + dynamic_debug_enabled2 |= + (1LL << dp->secondary_hash); + } else { + if (disabled_hash(dp->primary_hash, true)) + dynamic_debug_enabled &= + ~(1LL << dp->primary_hash); + if (disabled_hash(dp->secondary_hash, false)) + dynamic_debug_enabled2 &= + ~(1LL << dp->secondary_hash); + } + if (verbose) + printk(KERN_INFO + "ddebug: changed %s:%d [%s]%s %s\n", + dp->filename, dp->lineno, + dt->mod_name, dp->function, + ddebug_describe_flags(dp, flagbuf, + sizeof(flagbuf))); + } + } + mutex_unlock(&ddebug_lock); + + if (!nfound && verbose) + printk(KERN_INFO "ddebug: no matches for query\n"); +} + +/* + * Wrapper around strsep() to collapse the multiple empty tokens + * that it returns when fed sequences of separator characters. + * Now, if we had strtok_r()... + */ +static inline char *nearly_strtok_r(char **p, const char *sep) +{ + char *r; + + while ((r = strsep(p, sep)) != NULL && *r == '\0') + ; + return r; +} + +/* + * Split the buffer `buf' into space-separated words. + * Return the number of such words or <0 on error. + */ +static int ddebug_tokenize(char *buf, char *words[], int maxwords) +{ + int nwords = 0; + + while (nwords < maxwords && + (words[nwords] = nearly_strtok_r(&buf, " \t\r\n")) != NULL) + nwords++; + if (buf) + return -EINVAL; /* ran out of words[] before bytes */ + + if (verbose) { + int i; + printk(KERN_INFO "%s: split into words:", __func__); + for (i = 0 ; i < nwords ; i++) + printk(" \"%s\"", words[i]); + printk("\n"); + } + + return nwords; +} + +/* + * Parse a single line number. Note that the empty string "" + * is treated as a special case and converted to zero, which + * is later treated as a "don't care" value. + */ +static inline int parse_lineno(const char *str, unsigned int *val) +{ + char *end = NULL; + BUG_ON(str == NULL); + if (*str == '\0') { + *val = 0; + return 0; + } + *val = simple_strtoul(str, &end, 10); + return end == NULL || end == str || *end != '\0' ? -EINVAL : 0; +} + +/* + * Undo octal escaping in a string, inplace. This is useful to + * allow the user to express a query which matches a format + * containing embedded spaces. + */ +#define isodigit(c) ((c) >= '0' && (c) <= '7') +static char *unescape(char *str) +{ + char *in = str; + char *out = str; + + while (*in) { + if (*in == '\\') { + if (in[1] == '\\') { + *out++ = '\\'; + in += 2; + continue; + } else if (in[1] == 't') { + *out++ = '\t'; + in += 2; + continue; + } else if (in[1] == 'n') { + *out++ = '\n'; + in += 2; + continue; + } else if (isodigit(in[1]) && + isodigit(in[2]) && + isodigit(in[3])) { + *out++ = ((in[1] - '0')<<6) | + ((in[2] - '0')<<3) | + (in[3] - '0'); + in += 4; + continue; + } + } + *out++ = *in++; + } + *out = '\0'; + + return str; +} + +/* + * Parse words[] as a ddebug query specification, which is a series + * of (keyword, value) pairs chosen from these possibilities: + * + * func + * file + * file + * module + * format + * line + * line - // where either may be empty + */ +static int ddebug_parse_query(char *words[], int nwords, + struct ddebug_query *query) +{ + unsigned int i; + + /* check we have an even number of words */ + if (nwords % 2 != 0) + return -EINVAL; + memset(query, 0, sizeof(*query)); + + for (i = 0 ; i < nwords ; i += 2) { + if (!strcmp(words[i], "func")) + query->function = words[i+1]; + else if (!strcmp(words[i], "file")) + query->filename = words[i+1]; + else if (!strcmp(words[i], "module")) + query->module = words[i+1]; + else if (!strcmp(words[i], "format")) + query->format = unescape(words[i+1]); + else if (!strcmp(words[i], "line")) { + char *first = words[i+1]; + char *last = strchr(first, '-'); + if (last) + *last++ = '\0'; + if (parse_lineno(first, &query->first_lineno) < 0) + return -EINVAL; + if (last != NULL) { + /* range - */ + if (parse_lineno(last, &query->last_lineno) < 0) + return -EINVAL; + } else { + query->last_lineno = query->first_lineno; + } + } else { + if (verbose) + printk(KERN_ERR "%s: unknown keyword \"%s\"\n", + __func__, words[i]); + return -EINVAL; + } + } + + if (verbose) + printk(KERN_INFO "%s: q->function=\"%s\" q->filename=\"%s\" " + "q->module=\"%s\" q->format=\"%s\" q->lineno=%u-%u\n", + __func__, query->function, query->filename, + query->module, query->format, query->first_lineno, + query->last_lineno); + + return 0; +} + +/* + * Parse `str' as a flags specification, format [-+=][p]+. + * Sets up *maskp and *flagsp to be used when changing the + * flags fields of matched _ddebug's. Returns 0 on success + * or <0 on error. + */ +static int ddebug_parse_flags(const char *str, unsigned int *flagsp, + unsigned int *maskp) +{ + unsigned flags = 0; + int op = '='; + + switch (*str) { + case '+': + case '-': + case '=': + op = *str++; + break; + default: + return -EINVAL; + } + if (verbose) + printk(KERN_INFO "%s: op='%c'\n", __func__, op); + + for ( ; *str ; ++str) { + switch (*str) { + case 'p': + flags |= _DPRINTK_FLAGS_PRINT; + break; + default: + return -EINVAL; + } + } + if (flags == 0) + return -EINVAL; + if (verbose) + printk(KERN_INFO "%s: flags=0x%x\n", __func__, flags); + + /* calculate final *flagsp, *maskp according to mask and op */ + switch (op) { + case '=': + *maskp = 0; + *flagsp = flags; + break; + case '+': + *maskp = ~0U; + *flagsp = flags; + break; + case '-': + *maskp = ~flags; + *flagsp = 0; + break; + } + if (verbose) + printk(KERN_INFO "%s: *flagsp=0x%x *maskp=0x%x\n", + __func__, *flagsp, *maskp); + return 0; +} + +/* + * File_ops->write method for /dynamic_debug/conrol. Gathers the + * command text from userspace, parses and executes it. + */ +static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf, + size_t len, loff_t *offp) +{ + unsigned int flags = 0, mask = 0; + struct ddebug_query query; +#define MAXWORDS 9 + int nwords; + char *words[MAXWORDS]; + char tmpbuf[256]; + + if (len == 0) + return 0; + /* we don't check *offp -- multiple writes() are allowed */ + if (len > sizeof(tmpbuf)-1) + return -E2BIG; + if (copy_from_user(tmpbuf, ubuf, len)) + return -EFAULT; + tmpbuf[len] = '\0'; + if (verbose) + printk(KERN_INFO "%s: read %d bytes from userspace\n", + __func__, (int)len); + + nwords = ddebug_tokenize(tmpbuf, words, MAXWORDS); + if (nwords < 0) + return -EINVAL; + if (ddebug_parse_query(words, nwords-1, &query)) + return -EINVAL; + if (ddebug_parse_flags(words[nwords-1], &flags, &mask)) + return -EINVAL; + + /* actually go and implement the change */ + ddebug_change(&query, flags, mask); + + *offp += len; + return len; +} + +/* + * Set the iterator to point to the first _ddebug object + * and return a pointer to that first object. Returns + * NULL if there are no _ddebugs at all. + */ +static struct _ddebug *ddebug_iter_first(struct ddebug_iter *iter) +{ + if (list_empty(&ddebug_tables)) { + iter->table = NULL; + iter->idx = 0; + return NULL; + } + iter->table = list_entry(ddebug_tables.next, + struct ddebug_table, link); + iter->idx = 0; + return &iter->table->ddebugs[iter->idx]; +} + +/* + * Advance the iterator to point to the next _ddebug + * object from the one the iterator currently points at, + * and returns a pointer to the new _ddebug. Returns + * NULL if the iterator has seen all the _ddebugs. + */ +static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter) +{ + if (iter->table == NULL) + return NULL; + if (++iter->idx == iter->table->num_ddebugs) { + /* iterate to next table */ + iter->idx = 0; + if (list_is_last(&iter->table->link, &ddebug_tables)) { + iter->table = NULL; + return NULL; + } + iter->table = list_entry(iter->table->link.next, + struct ddebug_table, link); + } + return &iter->table->ddebugs[iter->idx]; +} + +/* + * Seq_ops start method. Called at the start of every + * read() call from userspace. Takes the ddebug_lock and + * seeks the seq_file's iterator to the given position. + */ +static void *ddebug_proc_start(struct seq_file *m, loff_t *pos) +{ + struct ddebug_iter *iter = m->private; + struct _ddebug *dp; + int n = *pos; + + if (verbose) + printk(KERN_INFO "%s: called m=%p *pos=%lld\n", + __func__, m, (unsigned long long)*pos); + + mutex_lock(&ddebug_lock); + + if (!n) + return SEQ_START_TOKEN; + if (n < 0) + return NULL; + dp = ddebug_iter_first(iter); + while (dp != NULL && --n > 0) + dp = ddebug_iter_next(iter); + return dp; +} + +/* + * Seq_ops next method. Called several times within a read() + * call from userspace, with ddebug_lock held. Walks to the + * next _ddebug object with a special case for the header line. + */ +static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos) +{ + struct ddebug_iter *iter = m->private; + struct _ddebug *dp; + + if (verbose) + printk(KERN_INFO "%s: called m=%p p=%p *pos=%lld\n", + __func__, m, p, (unsigned long long)*pos); + + if (p == SEQ_START_TOKEN) + dp = ddebug_iter_first(iter); + else + dp = ddebug_iter_next(iter); + ++*pos; + return dp; +} + +/* + * Seq_ops show method. Called several times within a read() + * call from userspace, with ddebug_lock held. Formats the + * current _ddebug as a single human-readable line, with a + * special case for the header line. + */ +static int ddebug_proc_show(struct seq_file *m, void *p) +{ + struct ddebug_iter *iter = m->private; + struct _ddebug *dp = p; + char flagsbuf[8]; + + if (verbose) + printk(KERN_INFO "%s: called m=%p p=%p\n", + __func__, m, p); + + if (p == SEQ_START_TOKEN) { + seq_puts(m, + "# filename:lineno [module]function flags format\n"); + return 0; + } + + seq_printf(m, "%s:%u [%s]%s %s \"", + dp->filename, dp->lineno, + iter->table->mod_name, dp->function, + ddebug_describe_flags(dp, flagsbuf, sizeof(flagsbuf))); + seq_escape(m, dp->format, "\t\r\n\""); + seq_puts(m, "\"\n"); + + return 0; +} + +/* + * Seq_ops stop method. Called at the end of each read() + * call from userspace. Drops ddebug_lock. + */ +static void ddebug_proc_stop(struct seq_file *m, void *p) +{ + if (verbose) + printk(KERN_INFO "%s: called m=%p p=%p\n", + __func__, m, p); + mutex_unlock(&ddebug_lock); +} + +static const struct seq_operations ddebug_proc_seqops = { + .start = ddebug_proc_start, + .next = ddebug_proc_next, + .show = ddebug_proc_show, + .stop = ddebug_proc_stop +}; + +/* + * File_ops->open method for /dynamic_debug/control. Does the seq_file + * setup dance, and also creates an iterator to walk the _ddebugs. + * Note that we create a seq_file always, even for O_WRONLY files + * where it's not needed, as doing so simplifies the ->release method. + */ +static int ddebug_proc_open(struct inode *inode, struct file *file) +{ + struct ddebug_iter *iter; + int err; + + if (verbose) + printk(KERN_INFO "%s: called\n", __func__); + + iter = kzalloc(sizeof(*iter), GFP_KERNEL); + if (iter == NULL) + return -ENOMEM; + + err = seq_open(file, &ddebug_proc_seqops); + if (err) { + kfree(iter); + return err; + } + ((struct seq_file *) file->private_data)->private = iter; + return 0; +} + +static const struct file_operations ddebug_proc_fops = { + .owner = THIS_MODULE, + .open = ddebug_proc_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release_private, + .write = ddebug_proc_write +}; + +/* + * Allocate a new ddebug_table for the given module + * and add it to the global list. + */ +int ddebug_add_module(struct _ddebug *tab, unsigned int n, + const char *name) +{ + struct ddebug_table *dt; + char *new_name; + + dt = kzalloc(sizeof(*dt), GFP_KERNEL); + if (dt == NULL) + return -ENOMEM; + new_name = kstrdup(name, GFP_KERNEL); + if (new_name == NULL) { + kfree(dt); + return -ENOMEM; + } + dt->mod_name = new_name; + dt->num_ddebugs = n; + dt->num_enabled = 0; + dt->ddebugs = tab; + + mutex_lock(&ddebug_lock); + list_add_tail(&dt->link, &ddebug_tables); + mutex_unlock(&ddebug_lock); + + if (verbose) + printk(KERN_INFO "%u debug prints in module %s\n", + n, dt->mod_name); + return 0; +} +EXPORT_SYMBOL_GPL(ddebug_add_module); + +static void ddebug_table_free(struct ddebug_table *dt) +{ + list_del_init(&dt->link); + kfree(dt->mod_name); + kfree(dt); +} + +/* + * Called in response to a module being unloaded. Removes + * any ddebug_table's which point at the module. + */ +int ddebug_remove_module(char *mod_name) +{ + struct ddebug_table *dt, *nextdt; + int ret = -ENOENT; + + if (verbose) + printk(KERN_INFO "%s: removing module \"%s\"\n", + __func__, mod_name); + + mutex_lock(&ddebug_lock); + list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) { + if (!strcmp(dt->mod_name, mod_name)) { + ddebug_table_free(dt); + ret = 0; + } + } + mutex_unlock(&ddebug_lock); + return ret; +} +EXPORT_SYMBOL_GPL(ddebug_remove_module); + +static void ddebug_remove_all_tables(void) +{ + mutex_lock(&ddebug_lock); + while (!list_empty(&ddebug_tables)) { + struct ddebug_table *dt = list_entry(ddebug_tables.next, + struct ddebug_table, + link); + ddebug_table_free(dt); + } + mutex_unlock(&ddebug_lock); +} + +static int __init dynamic_debug_init(void) +{ + struct dentry *dir, *file; + struct _ddebug *iter, *iter_start; + const char *modname = NULL; + int ret = 0; + int n = 0; + + dir = debugfs_create_dir("dynamic_debug", NULL); + if (!dir) + return -ENOMEM; + file = debugfs_create_file("control", 0644, dir, NULL, + &ddebug_proc_fops); + if (!file) { + debugfs_remove(dir); + return -ENOMEM; + } + if (__start___verbose != __stop___verbose) { + iter = __start___verbose; + modname = iter->modname; + iter_start = iter; + for (; iter < __stop___verbose; iter++) { + if (strcmp(modname, iter->modname)) { + ret = ddebug_add_module(iter_start, n, modname); + if (ret) + goto out_free; + n = 0; + modname = iter->modname; + iter_start = iter; + } + n++; + } + ret = ddebug_add_module(iter_start, n, modname); + } +out_free: + if (ret) { + ddebug_remove_all_tables(); + debugfs_remove(dir); + debugfs_remove(file); + } + return 0; +} +module_init(dynamic_debug_init); diff --git a/lib/dynamic_printk.c b/lib/dynamic_printk.c deleted file mode 100644 index 165a19763dc9..000000000000 --- a/lib/dynamic_printk.c +++ /dev/null @@ -1,414 +0,0 @@ -/* - * lib/dynamic_printk.c - * - * make pr_debug()/dev_dbg() calls runtime configurable based upon their - * their source module. - * - * Copyright (C) 2008 Red Hat, Inc., Jason Baron - */ - -#include -#include -#include -#include -#include -#include - -extern struct mod_debug __start___verbose[]; -extern struct mod_debug __stop___verbose[]; - -struct debug_name { - struct hlist_node hlist; - struct hlist_node hlist2; - int hash1; - int hash2; - char *name; - int enable; - int type; -}; - -static int nr_entries; -static int num_enabled; -int dynamic_enabled = DYNAMIC_ENABLED_NONE; -static struct hlist_head module_table[DEBUG_HASH_TABLE_SIZE] = - { [0 ... DEBUG_HASH_TABLE_SIZE-1] = HLIST_HEAD_INIT }; -static struct hlist_head module_table2[DEBUG_HASH_TABLE_SIZE] = - { [0 ... DEBUG_HASH_TABLE_SIZE-1] = HLIST_HEAD_INIT }; -static DECLARE_MUTEX(debug_list_mutex); - -/* dynamic_printk_enabled, and dynamic_printk_enabled2 are bitmasks in which - * bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They - * use independent hash functions, to reduce the chance of false positives. - */ -long long dynamic_printk_enabled; -EXPORT_SYMBOL_GPL(dynamic_printk_enabled); -long long dynamic_printk_enabled2; -EXPORT_SYMBOL_GPL(dynamic_printk_enabled2); - -/* returns the debug module pointer. */ -static struct debug_name *find_debug_module(char *module_name) -{ - int i; - struct hlist_head *head; - struct hlist_node *node; - struct debug_name *element; - - element = NULL; - for (i = 0; i < DEBUG_HASH_TABLE_SIZE; i++) { - head = &module_table[i]; - hlist_for_each_entry_rcu(element, node, head, hlist) - if (!strcmp(element->name, module_name)) - return element; - } - return NULL; -} - -/* returns the debug module pointer. */ -static struct debug_name *find_debug_module_hash(char *module_name, int hash) -{ - struct hlist_head *head; - struct hlist_node *node; - struct debug_name *element; - - element = NULL; - head = &module_table[hash]; - hlist_for_each_entry_rcu(element, node, head, hlist) - if (!strcmp(element->name, module_name)) - return element; - return NULL; -} - -/* caller must hold mutex*/ -static int __add_debug_module(char *mod_name, int hash, int hash2) -{ - struct debug_name *new; - char *module_name; - int ret = 0; - - if (find_debug_module(mod_name)) { - ret = -EINVAL; - goto out; - } - module_name = kmalloc(strlen(mod_name) + 1, GFP_KERNEL); - if (!module_name) { - ret = -ENOMEM; - goto out; - } - module_name = strcpy(module_name, mod_name); - module_name[strlen(mod_name)] = '\0'; - new = kzalloc(sizeof(struct debug_name), GFP_KERNEL); - if (!new) { - kfree(module_name); - ret = -ENOMEM; - goto out; - } - INIT_HLIST_NODE(&new->hlist); - INIT_HLIST_NODE(&new->hlist2); - new->name = module_name; - new->hash1 = hash; - new->hash2 = hash2; - hlist_add_head_rcu(&new->hlist, &module_table[hash]); - hlist_add_head_rcu(&new->hlist2, &module_table2[hash2]); - nr_entries++; -out: - return ret; -} - -int unregister_dynamic_debug_module(char *mod_name) -{ - struct debug_name *element; - int ret = 0; - - down(&debug_list_mutex); - element = find_debug_module(mod_name); - if (!element) { - ret = -EINVAL; - goto out; - } - hlist_del_rcu(&element->hlist); - hlist_del_rcu(&element->hlist2); - synchronize_rcu(); - kfree(element->name); - if (element->enable) - num_enabled--; - kfree(element); - nr_entries--; -out: - up(&debug_list_mutex); - return ret; -} -EXPORT_SYMBOL_GPL(unregister_dynamic_debug_module); - -int register_dynamic_debug_module(char *mod_name, int type, char *share_name, - char *flags, int hash, int hash2) -{ - struct debug_name *elem; - int ret = 0; - - down(&debug_list_mutex); - elem = find_debug_module(mod_name); - if (!elem) { - if (__add_debug_module(mod_name, hash, hash2)) - goto out; - elem = find_debug_module(mod_name); - if (dynamic_enabled == DYNAMIC_ENABLED_ALL && - !strcmp(mod_name, share_name)) { - elem->enable = true; - num_enabled++; - } - } - elem->type |= type; -out: - up(&debug_list_mutex); - return ret; -} -EXPORT_SYMBOL_GPL(register_dynamic_debug_module); - -int __dynamic_dbg_enabled_helper(char *mod_name, int type, int value, int hash) -{ - struct debug_name *elem; - int ret = 0; - - if (dynamic_enabled == DYNAMIC_ENABLED_ALL) - return 1; - rcu_read_lock(); - elem = find_debug_module_hash(mod_name, hash); - if (elem && elem->enable) - ret = 1; - rcu_read_unlock(); - return ret; -} -EXPORT_SYMBOL_GPL(__dynamic_dbg_enabled_helper); - -static void set_all(bool enable) -{ - struct debug_name *e; - struct hlist_node *node; - int i; - long long enable_mask; - - for (i = 0; i < DEBUG_HASH_TABLE_SIZE; i++) { - if (module_table[i].first != NULL) { - hlist_for_each_entry(e, node, &module_table[i], hlist) { - e->enable = enable; - } - } - } - if (enable) - enable_mask = ULLONG_MAX; - else - enable_mask = 0; - dynamic_printk_enabled = enable_mask; - dynamic_printk_enabled2 = enable_mask; -} - -static int disabled_hash(int i, bool first_table) -{ - struct debug_name *e; - struct hlist_node *node; - - if (first_table) { - hlist_for_each_entry(e, node, &module_table[i], hlist) { - if (e->enable) - return 0; - } - } else { - hlist_for_each_entry(e, node, &module_table2[i], hlist2) { - if (e->enable) - return 0; - } - } - return 1; -} - -static ssize_t pr_debug_write(struct file *file, const char __user *buf, - size_t length, loff_t *ppos) -{ - char *buffer, *s, *value_str, *setting_str; - int err, value; - struct debug_name *elem = NULL; - int all = 0; - - if (length > PAGE_SIZE || length < 0) - return -EINVAL; - - buffer = (char *)__get_free_page(GFP_KERNEL); - if (!buffer) - return -ENOMEM; - - err = -EFAULT; - if (copy_from_user(buffer, buf, length)) - goto out; - - err = -EINVAL; - if (length < PAGE_SIZE) - buffer[length] = '\0'; - else if (buffer[PAGE_SIZE-1]) - goto out; - - err = -EINVAL; - down(&debug_list_mutex); - - if (strncmp("set", buffer, 3)) - goto out_up; - s = buffer + 3; - setting_str = strsep(&s, "="); - if (s == NULL) - goto out_up; - setting_str = strstrip(setting_str); - value_str = strsep(&s, " "); - if (s == NULL) - goto out_up; - s = strstrip(s); - if (!strncmp(s, "all", 3)) - all = 1; - else - elem = find_debug_module(s); - if (!strncmp(setting_str, "enable", 6)) { - value = !!simple_strtol(value_str, NULL, 10); - if (all) { - if (value) { - set_all(true); - num_enabled = nr_entries; - dynamic_enabled = DYNAMIC_ENABLED_ALL; - } else { - set_all(false); - num_enabled = 0; - dynamic_enabled = DYNAMIC_ENABLED_NONE; - } - err = 0; - } else if (elem) { - if (value && (elem->enable == 0)) { - dynamic_printk_enabled |= (1LL << elem->hash1); - dynamic_printk_enabled2 |= (1LL << elem->hash2); - elem->enable = 1; - num_enabled++; - dynamic_enabled = DYNAMIC_ENABLED_SOME; - err = 0; - printk(KERN_DEBUG - "debugging enabled for module %s\n", - elem->name); - } else if (!value && (elem->enable == 1)) { - elem->enable = 0; - num_enabled--; - if (disabled_hash(elem->hash1, true)) - dynamic_printk_enabled &= - ~(1LL << elem->hash1); - if (disabled_hash(elem->hash2, false)) - dynamic_printk_enabled2 &= - ~(1LL << elem->hash2); - if (num_enabled) - dynamic_enabled = DYNAMIC_ENABLED_SOME; - else - dynamic_enabled = DYNAMIC_ENABLED_NONE; - err = 0; - printk(KERN_DEBUG - "debugging disabled for module %s\n", - elem->name); - } - } - } - if (!err) - err = length; -out_up: - up(&debug_list_mutex); -out: - free_page((unsigned long)buffer); - return err; -} - -static void *pr_debug_seq_start(struct seq_file *f, loff_t *pos) -{ - return (*pos < DEBUG_HASH_TABLE_SIZE) ? pos : NULL; -} - -static void *pr_debug_seq_next(struct seq_file *s, void *v, loff_t *pos) -{ - (*pos)++; - if (*pos >= DEBUG_HASH_TABLE_SIZE) - return NULL; - return pos; -} - -static void pr_debug_seq_stop(struct seq_file *s, void *v) -{ - /* Nothing to do */ -} - -static int pr_debug_seq_show(struct seq_file *s, void *v) -{ - struct hlist_head *head; - struct hlist_node *node; - struct debug_name *elem; - unsigned int i = *(loff_t *) v; - - rcu_read_lock(); - head = &module_table[i]; - hlist_for_each_entry_rcu(elem, node, head, hlist) { - seq_printf(s, "%s enabled=%d", elem->name, elem->enable); - seq_printf(s, "\n"); - } - rcu_read_unlock(); - return 0; -} - -static struct seq_operations pr_debug_seq_ops = { - .start = pr_debug_seq_start, - .next = pr_debug_seq_next, - .stop = pr_debug_seq_stop, - .show = pr_debug_seq_show -}; - -static int pr_debug_open(struct inode *inode, struct file *filp) -{ - return seq_open(filp, &pr_debug_seq_ops); -} - -static const struct file_operations pr_debug_operations = { - .open = pr_debug_open, - .read = seq_read, - .write = pr_debug_write, - .llseek = seq_lseek, - .release = seq_release, -}; - -static int __init dynamic_printk_init(void) -{ - struct dentry *dir, *file; - struct mod_debug *iter; - unsigned long value; - - dir = debugfs_create_dir("dynamic_printk", NULL); - if (!dir) - return -ENOMEM; - file = debugfs_create_file("modules", 0644, dir, NULL, - &pr_debug_operations); - if (!file) { - debugfs_remove(dir); - return -ENOMEM; - } - for (value = (unsigned long)__start___verbose; - value < (unsigned long)__stop___verbose; - value += sizeof(struct mod_debug)) { - iter = (struct mod_debug *)value; - register_dynamic_debug_module(iter->modname, - iter->type, - iter->logical_modname, - iter->flag_names, iter->hash, iter->hash2); - } - if (dynamic_enabled == DYNAMIC_ENABLED_ALL) - set_all(true); - return 0; -} -module_init(dynamic_printk_init); -/* may want to move this earlier so we can get traces as early as possible */ - -static int __init dynamic_printk_setup(char *str) -{ - if (str) - return -ENOENT; - dynamic_enabled = DYNAMIC_ENABLED_ALL; - return 0; -} -/* Use early_param(), so we can get debug output as early as possible */ -early_param("dynamic_printk", dynamic_printk_setup); diff --git a/net/netfilter/nf_conntrack_pptp.c b/net/netfilter/nf_conntrack_pptp.c index 9e169ef2e854..12bd09dbd36c 100644 --- a/net/netfilter/nf_conntrack_pptp.c +++ b/net/netfilter/nf_conntrack_pptp.c @@ -66,7 +66,7 @@ void struct nf_conntrack_expect *exp) __read_mostly; EXPORT_SYMBOL_GPL(nf_nat_pptp_hook_expectfn); -#if defined(DEBUG) || defined(CONFIG_DYNAMIC_PRINTK_DEBUG) +#if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG) /* PptpControlMessageType names */ const char *const pptp_msg_name[] = { "UNKNOWN_MESSAGE", diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index e06365775bdf..c18fa150b6fe 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -97,7 +97,7 @@ modname_flags = $(if $(filter 1,$(words $(modname))),\ -D"KBUILD_MODNAME=KBUILD_STR($(call name-fix,$(modname)))") #hash values -ifdef CONFIG_DYNAMIC_PRINTK_DEBUG +ifdef CONFIG_DYNAMIC_DEBUG debug_flags = -D"DEBUG_HASH=$(shell ./scripts/basic/hash djb2 $(@D)$(modname))"\ -D"DEBUG_HASH2=$(shell ./scripts/basic/hash r5 $(@D)$(modname))" else -- cgit v1.3-14-g43fede From 86151fdf38b3795f292b39defbff39d2684b9c8c Mon Sep 17 00:00:00 2001 From: Jason Baron Date: Thu, 5 Feb 2009 11:53:15 -0500 Subject: dynamic debug: update docs updates the documentation for 'dynamic debug' feature. Signed-off-by: Greg Banks Signed-off-by: Jason Baron Signed-off-by: Greg Kroah-Hartman --- Documentation/dynamic-debug-howto.txt | 232 ++++++++++++++++++++++++++++++++++ lib/Kconfig.debug | 72 ++++++----- 2 files changed, 273 insertions(+), 31 deletions(-) create mode 100644 Documentation/dynamic-debug-howto.txt (limited to 'lib/Kconfig.debug') diff --git a/Documentation/dynamic-debug-howto.txt b/Documentation/dynamic-debug-howto.txt new file mode 100644 index 000000000000..68394825e86b --- /dev/null +++ b/Documentation/dynamic-debug-howto.txt @@ -0,0 +1,232 @@ + +Introduction +============ + +This document describes how to use the dynamic debug (ddebug) feature. + +Dynamic debug is designed to allow you to dynamically enable/disable kernel +code to obtain additional kernel information. Currently, if +CONFIG_DYNAMIC_DEBUG is set, then all pr_debug()/dev_debug() calls can be +dynamically enabled per-callsite. + +Dynamic debug has even more useful features: + + * Simple query language allows turning on and off debugging statements by + matching any combination of: + + - source filename + - function name + - line number (including ranges of line numbers) + - module name + - format string + + * Provides a debugfs control file: /dynamic_debug/control which can be + read to display the complete list of known debug statements, to help guide you + +Controlling dynamic debug Behaviour +=============================== + +The behaviour of pr_debug()/dev_debug()s are controlled via writing to a +control file in the 'debugfs' filesystem. Thus, you must first mount the debugfs +filesystem, in order to make use of this feature. Subsequently, we refer to the +control file as: /dynamic_debug/control. For example, if you want to +enable printing from source file 'svcsock.c', line 1603 you simply do: + +nullarbor:~ # echo 'file svcsock.c line 1603 +p' > + /dynamic_debug/control + +If you make a mistake with the syntax, the write will fail thus: + +nullarbor:~ # echo 'file svcsock.c wtf 1 +p' > + /dynamic_debug/control +-bash: echo: write error: Invalid argument + +Viewing Dynamic Debug Behaviour +=========================== + +You can view the currently configured behaviour of all the debug statements +via: + +nullarbor:~ # cat /dynamic_debug/control +# filename:lineno [module]function flags format +/usr/src/packages/BUILD/sgi-enhancednfs-1.4/default/net/sunrpc/svc_rdma.c:323 [svcxprt_rdma]svc_rdma_cleanup - "SVCRDMA\040Module\040Removed,\040deregister\040RPC\040RDMA\040transport\012" +/usr/src/packages/BUILD/sgi-enhancednfs-1.4/default/net/sunrpc/svc_rdma.c:341 [svcxprt_rdma]svc_rdma_init - "\011max_inline\040\040\040\040\040\040\040:\040%d\012" +/usr/src/packages/BUILD/sgi-enhancednfs-1.4/default/net/sunrpc/svc_rdma.c:340 [svcxprt_rdma]svc_rdma_init - "\011sq_depth\040\040\040\040\040\040\040\040\040:\040%d\012" +/usr/src/packages/BUILD/sgi-enhancednfs-1.4/default/net/sunrpc/svc_rdma.c:338 [svcxprt_rdma]svc_rdma_init - "\011max_requests\040\040\040\040\040:\040%d\012" +... + + +You can also apply standard Unix text manipulation filters to this +data, e.g. + +nullarbor:~ # grep -i rdma /dynamic_debug/control | wc -l +62 + +nullarbor:~ # grep -i tcp /dynamic_debug/control | wc -l +42 + +Note in particular that the third column shows the enabled behaviour +flags for each debug statement callsite (see below for definitions of the +flags). The default value, no extra behaviour enabled, is "-". So +you can view all the debug statement callsites with any non-default flags: + +nullarbor:~ # awk '$3 != "-"' /dynamic_debug/control +# filename:lineno [module]function flags format +/usr/src/packages/BUILD/sgi-enhancednfs-1.4/default/net/sunrpc/svcsock.c:1603 [sunrpc]svc_send p "svc_process:\040st_sendto\040returned\040%d\012" + + +Command Language Reference +========================== + +At the lexical level, a command comprises a sequence of words separated +by whitespace characters. Note that newlines are treated as word +separators and do *not* end a command or allow multiple commands to +be done together. So these are all equivalent: + +nullarbor:~ # echo -c 'file svcsock.c line 1603 +p' > + /dynamic_debug/control +nullarbor:~ # echo -c ' file svcsock.c line 1603 +p ' > + /dynamic_debug/control +nullarbor:~ # echo -c 'file svcsock.c\nline 1603 +p' > + /dynamic_debug/control +nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' > + /dynamic_debug/control + +Commands are bounded by a write() system call. If you want to do +multiple commands you need to do a separate "echo" for each, like: + +nullarbor:~ # echo 'file svcsock.c line 1603 +p' > /proc/dprintk ;\ +> echo 'file svcsock.c line 1563 +p' > /proc/dprintk + +or even like: + +nullarbor:~ # ( +> echo 'file svcsock.c line 1603 +p' ;\ +> echo 'file svcsock.c line 1563 +p' ;\ +> ) > /proc/dprintk + +At the syntactical level, a command comprises a sequence of match +specifications, followed by a flags change specification. + +command ::= match-spec* flags-spec + +The match-spec's are used to choose a subset of the known dprintk() +callsites to which to apply the flags-spec. Think of them as a query +with implicit ANDs between each pair. Note that an empty list of +match-specs is possible, but is not very useful because it will not +match any debug statement callsites. + +A match specification comprises a keyword, which controls the attribute +of the callsite to be compared, and a value to compare against. Possible +keywords are: + +match-spec ::= 'func' string | + 'file' string | + 'module' string | + 'format' string | + 'line' line-range + +line-range ::= lineno | + '-'lineno | + lineno'-' | + lineno'-'lineno +// Note: line-range cannot contain space, e.g. +// "1-30" is valid range but "1 - 30" is not. + +lineno ::= unsigned-int + +The meanings of each keyword are: + +func + The given string is compared against the function name + of each callsite. Example: + + func svc_tcp_accept + +file + The given string is compared against either the full + pathname or the basename of the source file of each + callsite. Examples: + + file svcsock.c + file /usr/src/packages/BUILD/sgi-enhancednfs-1.4/default/net/sunrpc/svcsock.c + +module + The given string is compared against the module name + of each callsite. The module name is the string as + seen in "lsmod", i.e. without the directory or the .ko + suffix and with '-' changed to '_'. Examples: + + module sunrpc + module nfsd + +format + The given string is searched for in the dynamic debug format + string. Note that the string does not need to match the + entire format, only some part. Whitespace and other + special characters can be escaped using C octal character + escape \ooo notation, e.g. the space character is \040. + Examples: + + format svcrdma: // many of the NFS/RDMA server dprintks + format readahead // some dprintks in the readahead cache + format nfsd:\040SETATTR // how to match a format with whitespace + +line + The given line number or range of line numbers is compared + against the line number of each dprintk() callsite. A single + line number matches the callsite line number exactly. A + range of line numbers matches any callsite between the first + and last line number inclusive. An empty first number means + the first line in the file, an empty line number means the + last number in the file. Examples: + + line 1603 // exactly line 1603 + line 1600-1605 // the six lines from line 1600 to line 1605 + line -1605 // the 1605 lines from line 1 to line 1605 + line 1600- // all lines from line 1600 to the end of the file + +The flags specification comprises a change operation followed +by one or more flag characters. The change operation is one +of the characters: + +- + remove the given flags + ++ + add the given flags + += + set the flags to the given flags + +The flags are: + +p + Causes a printk() message to be emitted to dmesg + +Note the regexp ^[-+=][scp]+$ matches a flags specification. +Note also that there is no convenient syntax to remove all +the flags at once, you need to use "-psc". + +Examples +======== + +// enable the message at line 1603 of file svcsock.c +nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' > + /dynamic_debug/control + +// enable all the messages in file svcsock.c +nullarbor:~ # echo -n 'file svcsock.c +p' > + /dynamic_debug/control + +// enable all the messages in the NFS server module +nullarbor:~ # echo -n 'module nfsd +p' > + /dynamic_debug/control + +// enable all 12 messages in the function svc_process() +nullarbor:~ # echo -n 'func svc_process +p' > + /dynamic_debug/control + +// disable all 12 messages in the function svc_process() +nullarbor:~ # echo -n 'func svc_process -p' > + /dynamic_debug/control diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 0dd1c04c7323..8fee0a13ac58 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -848,59 +848,69 @@ config BUILD_DOCSRC Say N if you are unsure. config DYNAMIC_DEBUG - bool "Enable dynamic printk() call support" + bool "Enable dynamic printk() support" default n depends on PRINTK + depends on DEBUG_FS select PRINTK_DEBUG help Compiles debug level messages into the kernel, which would not otherwise be available at runtime. These messages can then be - enabled/disabled on a per module basis. This mechanism implicitly - enables all pr_debug() and dev_dbg() calls. The impact of this - compile option is a larger kernel text size of about 2%. + enabled/disabled based on various levels of scope - per source file, + function, module, format string, and line number. This mechanism + implicitly enables all pr_debug() and dev_dbg() calls. The impact of + this compile option is a larger kernel text size of about 2%. Usage: - Dynamic debugging is controlled by the debugfs file, - dynamic_printk/modules. This file contains a list of the modules that - can be enabled. The format of the file is the module name, followed - by a set of flags that can be enabled. The first flag is always the - 'enabled' flag. For example: + Dynamic debugging is controlled via the 'dynamic_debug/ddebug' file, + which is contained in the 'debugfs' filesystem. Thus, the debugfs + filesystem must first be mounted before making use of this feature. + We refer the control file as: /dynamic_debug/ddebug. This + file contains a list of the debug statements that can be enabled. The + format for each line of the file is: - - . - . - . + filename:lineno [module]function flags format - : Name of the module in which the debug call resides - : whether the messages are enabled or not + filename : source file of the debug statement + lineno : line number of the debug statement + module : module that contains the debug statement + function : function that contains the debug statement + flags : 'p' means the line is turned 'on' for printing + format : the format used for the debug statement From a live system: - snd_hda_intel enabled=0 - fixup enabled=0 - driver enabled=0 + nullarbor:~ # cat /dynamic_debug/ddebug + # filename:lineno [module]function flags format + fs/aio.c:222 [aio]__put_ioctx - "__put_ioctx:\040freeing\040%p\012" + fs/aio.c:248 [aio]ioctx_alloc - "ENOMEM:\040nr_events\040too\040high\012" + fs/aio.c:1770 [aio]sys_io_cancel - "calling\040cancel\012" - Enable a module: + Example usage: - $echo "set enabled=1 " > dynamic_printk/modules + // enable the message at line 1603 of file svcsock.c + nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' > + /dynamic_debug/ddebug - Disable a module: + // enable all the messages in file svcsock.c + nullarbor:~ # echo -n 'file svcsock.c +p' > + /dynamic_debug/ddebug - $echo "set enabled=0 " > dynamic_printk/modules + // enable all the messages in the NFS server module + nullarbor:~ # echo -n 'module nfsd +p' > + /dynamic_debug/ddebug - Enable all modules: + // enable all 12 messages in the function svc_process() + nullarbor:~ # echo -n 'func svc_process +p' > + /dynamic_debug/ddebug - $echo "set enabled=1 all" > dynamic_printk/modules + // disable all 12 messages in the function svc_process() + nullarbor:~ # echo -n 'func svc_process -p' > + /dynamic_debug/ddebug - Disable all modules: - - $echo "set enabled=0 all" > dynamic_printk/modules - - Finally, passing "dynamic_printk" at the command line enables - debugging for all modules. This mode can be turned off via the above - disable command. + See Documentation/dynamic-debug-howto.txt for additional information. source "samples/Kconfig" -- cgit v1.3-14-g43fede From 6a11f75b6a17b5d9ac5025f8d048382fd1f47377 Mon Sep 17 00:00:00 2001 From: Akinobu Mita Date: Tue, 31 Mar 2009 15:23:17 -0700 Subject: generic debug pagealloc CONFIG_DEBUG_PAGEALLOC is now supported by x86, powerpc, sparc64, and s390. This patch implements it for the rest of the architectures by filling the pages with poison byte patterns after free_pages() and verifying the poison patterns before alloc_pages(). This generic one cannot detect invalid page accesses immediately but invalid read access may cause invalid dereference by poisoned memory and invalid write access can be detected after a long delay. Signed-off-by: Akinobu Mita Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/avr32/mm/fault.c | 18 ------ arch/powerpc/Kconfig | 3 + arch/powerpc/Kconfig.debug | 1 + arch/s390/Kconfig | 3 + arch/s390/Kconfig.debug | 1 + arch/sparc/Kconfig | 3 + arch/sparc/Kconfig.debug | 3 +- arch/x86/Kconfig | 3 + arch/x86/Kconfig.debug | 1 + include/linux/mm_types.h | 4 ++ include/linux/page-debug-flags.h | 30 +++++++++ include/linux/poison.h | 3 + lib/Kconfig.debug | 1 + mm/Kconfig.debug | 17 ++++++ mm/Makefile | 1 + mm/debug-pagealloc.c | 129 +++++++++++++++++++++++++++++++++++++++ 16 files changed, 202 insertions(+), 19 deletions(-) create mode 100644 include/linux/page-debug-flags.h create mode 100644 mm/Kconfig.debug create mode 100644 mm/debug-pagealloc.c (limited to 'lib/Kconfig.debug') diff --git a/arch/avr32/mm/fault.c b/arch/avr32/mm/fault.c index ce4e4296b954..62d4abbaa654 100644 --- a/arch/avr32/mm/fault.c +++ b/arch/avr32/mm/fault.c @@ -250,21 +250,3 @@ asmlinkage void do_bus_error(unsigned long addr, int write_access, dump_dtlb(); die("Bus Error", regs, SIGKILL); } - -/* - * This functionality is currently not possible to implement because - * we're using segmentation to ensure a fixed mapping of the kernel - * virtual address space. - * - * It would be possible to implement this, but it would require us to - * disable segmentation at startup and load the kernel mappings into - * the TLB like any other pages. There will be lots of trickery to - * avoid recursive invocation of the TLB miss handler, though... - */ -#ifdef CONFIG_DEBUG_PAGEALLOC -void kernel_map_pages(struct page *page, int numpages, int enable) -{ - -} -EXPORT_SYMBOL(kernel_map_pages); -#endif diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index ad6b1c084fe3..45192dce65c4 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -228,6 +228,9 @@ config PPC_OF_PLATFORM_PCI depends on PPC64 # not supported on 32 bits yet default n +config ARCH_SUPPORTS_DEBUG_PAGEALLOC + def_bool y + source "init/Kconfig" source "kernel/Kconfig.freezer" diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug index 22091bbfdc9b..6aa0b5e087cd 100644 --- a/arch/powerpc/Kconfig.debug +++ b/arch/powerpc/Kconfig.debug @@ -30,6 +30,7 @@ config DEBUG_STACK_USAGE config DEBUG_PAGEALLOC bool "Debug page memory allocations" depends on DEBUG_KERNEL && !HIBERNATION + depends on ARCH_SUPPORTS_DEBUG_PAGEALLOC help Unmap pages from the kernel linear mapping after free_pages(). This results in a large slowdown, but helps to find certain types diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 2a8af5e16345..dcb667c4375a 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -72,6 +72,9 @@ config PGSTE config VIRT_CPU_ACCOUNTING def_bool y +config ARCH_SUPPORTS_DEBUG_PAGEALLOC + def_bool y + mainmenu "Linux Kernel Configuration" config S390 diff --git a/arch/s390/Kconfig.debug b/arch/s390/Kconfig.debug index 4599fa06bd82..7e297a3cde34 100644 --- a/arch/s390/Kconfig.debug +++ b/arch/s390/Kconfig.debug @@ -9,6 +9,7 @@ source "lib/Kconfig.debug" config DEBUG_PAGEALLOC bool "Debug page memory allocations" depends on DEBUG_KERNEL + depends on ARCH_SUPPORTS_DEBUG_PAGEALLOC help Unmap pages from the kernel linear mapping after free_pages(). This results in a slowdown, but helps to find certain types of diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig index c3ea215334f6..cc12cd48bbc5 100644 --- a/arch/sparc/Kconfig +++ b/arch/sparc/Kconfig @@ -124,6 +124,9 @@ config ARCH_NO_VIRT_TO_BUS config OF def_bool y +config ARCH_SUPPORTS_DEBUG_PAGEALLOC + def_bool y if SPARC64 + source "init/Kconfig" source "kernel/Kconfig.freezer" diff --git a/arch/sparc/Kconfig.debug b/arch/sparc/Kconfig.debug index b8a15e271bfa..d001b42041a5 100644 --- a/arch/sparc/Kconfig.debug +++ b/arch/sparc/Kconfig.debug @@ -24,7 +24,8 @@ config STACK_DEBUG config DEBUG_PAGEALLOC bool "Debug page memory allocations" - depends on SPARC64 && DEBUG_KERNEL && !HIBERNATION + depends on DEBUG_KERNEL && !HIBERNATION + depends on ARCH_SUPPORTS_DEBUG_PAGEALLOC help Unmap pages from the kernel linear mapping after free_pages(). This results in a large slowdown, but helps to find certain types diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 45161b816313..748e50a1a152 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -165,6 +165,9 @@ config AUDIT_ARCH config ARCH_SUPPORTS_OPTIMIZED_INLINING def_bool y +config ARCH_SUPPORTS_DEBUG_PAGEALLOC + def_bool y + # Use the generic interrupt handling code in kernel/irq/: config GENERIC_HARDIRQS bool diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index fdb45df608b6..a345cb5447a8 100644 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -75,6 +75,7 @@ config DEBUG_STACK_USAGE config DEBUG_PAGEALLOC bool "Debug page memory allocations" depends on DEBUG_KERNEL + depends on ARCH_SUPPORTS_DEBUG_PAGEALLOC ---help--- Unmap pages from the kernel linear mapping after free_pages(). This results in a large slowdown, but helps to find certain types diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index d84feb7bdbf0..ddadb4defe00 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -11,6 +11,7 @@ #include #include #include +#include #include #include @@ -174,6 +175,9 @@ struct vm_area_struct { #ifdef CONFIG_NUMA struct mempolicy *vm_policy; /* NUMA policy for the VMA */ #endif +#ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS + unsigned long debug_flags; /* Use atomic bitops on this */ +#endif }; struct core_thread { diff --git a/include/linux/page-debug-flags.h b/include/linux/page-debug-flags.h new file mode 100644 index 000000000000..b0638fd91e92 --- /dev/null +++ b/include/linux/page-debug-flags.h @@ -0,0 +1,30 @@ +#ifndef LINUX_PAGE_DEBUG_FLAGS_H +#define LINUX_PAGE_DEBUG_FLAGS_H + +/* + * page->debug_flags bits: + * + * PAGE_DEBUG_FLAG_POISON is set for poisoned pages. This is used to + * implement generic debug pagealloc feature. The pages are filled with + * poison patterns and set this flag after free_pages(). The poisoned + * pages are verified whether the patterns are not corrupted and clear + * the flag before alloc_pages(). + */ + +enum page_debug_flags { + PAGE_DEBUG_FLAG_POISON, /* Page is poisoned */ +}; + +/* + * Ensure that CONFIG_WANT_PAGE_DEBUG_FLAGS reliably + * gets turned off when no debug features are enabling it! + */ + +#ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS +#if !defined(CONFIG_PAGE_POISONING) \ +/* && !defined(CONFIG_PAGE_DEBUG_SOMETHING_ELSE) && ... */ +#error WANT_PAGE_DEBUG_FLAGS is turned on with no debug features! +#endif +#endif /* CONFIG_WANT_PAGE_DEBUG_FLAGS */ + +#endif /* LINUX_PAGE_DEBUG_FLAGS_H */ diff --git a/include/linux/poison.h b/include/linux/poison.h index 9f31683728fd..6729f7dcd60e 100644 --- a/include/linux/poison.h +++ b/include/linux/poison.h @@ -17,6 +17,9 @@ */ #define TIMER_ENTRY_STATIC ((void *) 0x74737461) +/********** mm/debug-pagealloc.c **********/ +#define PAGE_POISON 0xaa + /********** mm/slab.c **********/ /* * Magic nums for obj red zoning. diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 58bfe7e8faba..9638d99644af 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -796,6 +796,7 @@ config SYSCTL_SYSCALL_CHECK to properly maintain and use. This enables checks that help you to keep things correct. +source mm/Kconfig.debug source kernel/trace/Kconfig config PROVIDE_OHCI1394_DMA_INIT diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug new file mode 100644 index 000000000000..c8d62d49a44e --- /dev/null +++ b/mm/Kconfig.debug @@ -0,0 +1,17 @@ +config WANT_PAGE_DEBUG_FLAGS + bool + +config PAGE_POISONING + bool "Debug page memory allocations" + depends on DEBUG_KERNEL && !ARCH_SUPPORTS_DEBUG_PAGEALLOC + depends on !HIBERNATION + select DEBUG_PAGEALLOC + select WANT_PAGE_DEBUG_FLAGS + help + Fill the pages with poison patterns after free_pages() and verify + the patterns before alloc_pages(). This results in a large slowdown, + but helps to find certain types of memory corruptions. + + This option cannot enalbe with hibernation. Otherwise, it will get + wrong messages for memory corruption because the free pages are not + saved to the suspend image. diff --git a/mm/Makefile b/mm/Makefile index 818569b68f46..ec73c68b6015 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -24,6 +24,7 @@ obj-$(CONFIG_SPARSEMEM_VMEMMAP) += sparse-vmemmap.o obj-$(CONFIG_TMPFS_POSIX_ACL) += shmem_acl.o obj-$(CONFIG_SLOB) += slob.o obj-$(CONFIG_MMU_NOTIFIER) += mmu_notifier.o +obj-$(CONFIG_PAGE_POISONING) += debug-pagealloc.o obj-$(CONFIG_SLAB) += slab.o obj-$(CONFIG_SLUB) += slub.o obj-$(CONFIG_FAILSLAB) += failslab.o diff --git a/mm/debug-pagealloc.c b/mm/debug-pagealloc.c new file mode 100644 index 000000000000..a1e3324de2b5 --- /dev/null +++ b/mm/debug-pagealloc.c @@ -0,0 +1,129 @@ +#include +#include +#include +#include + +static inline void set_page_poison(struct page *page) +{ + __set_bit(PAGE_DEBUG_FLAG_POISON, &page->debug_flags); +} + +static inline void clear_page_poison(struct page *page) +{ + __clear_bit(PAGE_DEBUG_FLAG_POISON, &page->debug_flags); +} + +static inline bool page_poison(struct page *page) +{ + return test_bit(PAGE_DEBUG_FLAG_POISON, &page->debug_flags); +} + +static void poison_highpage(struct page *page) +{ + /* + * Page poisoning for highmem pages is not implemented. + * + * This can be called from interrupt contexts. + * So we need to create a new kmap_atomic slot for this + * application and it will need interrupt protection. + */ +} + +static void poison_page(struct page *page) +{ + void *addr; + + if (PageHighMem(page)) { + poison_highpage(page); + return; + } + set_page_poison(page); + addr = page_address(page); + memset(addr, PAGE_POISON, PAGE_SIZE); +} + +static void poison_pages(struct page *page, int n) +{ + int i; + + for (i = 0; i < n; i++) + poison_page(page + i); +} + +static bool single_bit_flip(unsigned char a, unsigned char b) +{ + unsigned char error = a ^ b; + + return error && !(error & (error - 1)); +} + +static void check_poison_mem(unsigned char *mem, size_t bytes) +{ + unsigned char *start; + unsigned char *end; + + for (start = mem; start < mem + bytes; start++) { + if (*start != PAGE_POISON) + break; + } + if (start == mem + bytes) + return; + + for (end = mem + bytes - 1; end > start; end--) { + if (*end != PAGE_POISON) + break; + } + + if (!printk_ratelimit()) + return; + else if (start == end && single_bit_flip(*start, PAGE_POISON)) + printk(KERN_ERR "pagealloc: single bit error\n"); + else + printk(KERN_ERR "pagealloc: memory corruption\n"); + + print_hex_dump(KERN_ERR, "", DUMP_PREFIX_ADDRESS, 16, 1, start, + end - start + 1, 1); + dump_stack(); +} + +static void unpoison_highpage(struct page *page) +{ + /* + * See comment in poison_highpage(). + * Highmem pages should not be poisoned for now + */ + BUG_ON(page_poison(page)); +} + +static void unpoison_page(struct page *page) +{ + if (PageHighMem(page)) { + unpoison_highpage(page); + return; + } + if (page_poison(page)) { + void *addr = page_address(page); + + check_poison_mem(addr, PAGE_SIZE); + clear_page_poison(page); + } +} + +static void unpoison_pages(struct page *page, int n) +{ + int i; + + for (i = 0; i < n; i++) + unpoison_page(page + i); +} + +void kernel_map_pages(struct page *page, int numpages, int enable) +{ + if (!debug_pagealloc_enabled) + return; + + if (enable) + unpoison_pages(page, numpages); + else + poison_pages(page, numpages); +} -- cgit v1.3-14-g43fede From 77d05632baee21b1cef8730d7c06aa69601e4dca Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Tue, 7 Apr 2009 08:55:36 +0200 Subject: softlockup: make DETECT_HUNG_TASK default depend on DETECT_SOFTLOCKUP Don't offer a default-y option when the user has turned off CONFIG_DETECT_SOFTLOCKUP already. Do offer it as 'y' only if DETECT_SOFTLOCKUP is on already. This makes it match previous behavior - where the hung-task check was embedded i CONFIG_DETECT_SOFTLOCKUP code. Cc: Linus Torvalds Signed-off-by: Ingo Molnar --- lib/Kconfig.debug | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib/Kconfig.debug') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 4934eaa21e1e..898e07c33c3c 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -189,7 +189,7 @@ config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE config DETECT_HUNG_TASK bool "Detect Hung Tasks" depends on DEBUG_KERNEL - default y + default DETECT_SOFTLOCKUP help Say Y here to enable the kernel to detect "hung tasks", which are bugs that cause the task to be stuck in -- cgit v1.3-14-g43fede