--- arch/i386/kernel/traps.c | 2 arch/i386/mm/fault.c | 3 drivers/char/sysrq.c | 40 + include/linux/logdev.h | 193 ++++++ kernel/Makefile | 1 kernel/logdev/Makefile | 7 kernel/logdev/logdev.c | 1269 +++++++++++++++++++++++++++++++++++++++ kernel/logdev/logdev_priv.h | 52 + kernel/logdev/logdev_probe.c | 1310 +++++++++++++++++++++++++++++++++++++++++ kernel/logdev/logdev_relay.c | 175 +++++ kernel/logdev/logdev_ringbuf.c | 482 +++++++++++++++ kernel/logdev/logdev_ringbuf.h | 158 ++++ lib/Kconfig.debug | 70 ++ 13 files changed, 3759 insertions(+), 3 deletions(-) Index: linux-2.6.21.5-rt20/include/linux/logdev.h =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ linux-2.6.21.5-rt20/include/linux/logdev.h 2007-07-11 14:28:50.000000000 +0200 @@ -0,0 +1,193 @@ +/* + * Logdevice - A device used to record debuging information in the kernel. + * It uses a large memory ring buffer consisting of individual pages + * to keep down on hogging large sections. A user may then read the device + * to get debugging information out of it. Or if configured, this can + * be dumped to the network on a system crash. + * + * Copyright - 2005 - Steven Rostedt, Kihon Technologies, (rostedt at kihontech dot com) + */ +#ifndef _LOG_DEV_H +#define _LOG_DEV_H + +#include + +struct logdev_switch_struct { + unsigned long long t; + short pid_prev; + short pid_next; + int prev_prio; + int prev_static_prio; + int prev_normal_prio; + int prev_state; + int next_prio; + int next_static_prio; + int next_normal_prio; + char prev_comm[TASK_COMM_LEN]; + char next_comm[TASK_COMM_LEN]; +}; + +struct logdev_print { + char str[0]; +}; + +struct logdev_print_time { + unsigned long long t; + char str[0]; +}; + +struct logdev_print_time_func { + const char *file; + int line; + /* need to be after line, since we use this with print_time. */ + unsigned long long t; + char str[0]; +}; + +struct logdev_custom { + int id; + char data[0]; +}; + +struct logdev_header { + long counter; + int id; + int size; +}; + +struct logdev_item { + struct logdev_header hdr; + union { + struct logdev_switch_struct sw; + struct logdev_print print; + struct logdev_print_time print_time; + struct logdev_print_time_func print_time_func; + struct logdev_custom custom; + char data[0]; + } u; +}; + +#ifdef CONFIG_LOGDEV + +extern int in_logdump; + +/* + * Right now we only have one switch, but this may change + * in the future. + */ +extern unsigned long logdev_switches; +#define LOGDEV_SW_PRINT_ENABLED 0 +#define LOGDEV_SW_SWITCH_ENABLED 1 +#define LOGDEV_SW_MARKER_ENABLED 2 +#define LOGDEV_SW_BITS 3 + +#define LOGDEV_SW_ISSET(sw) (test_bit(sw, &logdev_switches)) +#define LOGDEV_SW_SET(sw) (set_bit(sw, &logdev_switches)) +#define LOGDEV_SW_CLEAR(sw) (clear_bit(sw, &logdev_switches)) + +#define logdev_print_ison() LOGDEV_SW_ISSET(LOGDEV_SW_PRINT_ENABLED) +#define logdev_print_on() LOGDEV_SW_SET(LOGDEV_SW_PRINT_ENABLED); +#define logdev_print_off() LOGDEV_SW_CLEAR(LOGDEV_SW_PRINT_ENABLED); + +#define logdev_switch_ison() LOGDEV_SW_ISSET(LOGDEV_SW_SWITCH_ENABLED) +#define logdev_switch_on() LOGDEV_SW_SET(LOGDEV_SW_SWITCH_ENABLED); +#define logdev_switch_off() LOGDEV_SW_CLEAR(LOGDEV_SW_SWITCH_ENABLED); + +#define logdev_mark_ison() LOGDEV_SW_ISSET(LOGDEV_SW_MARKER_ENABLED) +#define logdev_mark_on() LOGDEV_SW_SET(LOGDEV_SW_MARKER_ENABLED); +#define logdev_mark_off() LOGDEV_SW_CLEAR(LOGDEV_SW_MARKER_ENABLED); + +typedef void (*logdev_callback_func)(struct logdev_header *hdr, + struct logdev_custom *custom, + int cpu, + void *rec); + +int logdev_print(const char *str, ...) + __attribute__ ((format (printf, 1, 2))); +int logdev_vprint(const char *str, va_list va); +int logdev_print_time(const char *str, ...) + __attribute__ ((format (printf, 1, 2))); +int logdev_print_time_func(const char *file, int line, const char *str, ...) + __attribute__ ((format (printf, 3, 4))); + +/* + * logdev_record is used for custom writes (saves of sprintf) + * use id and register a callback so that the logdump knows + * what to do when it sees this record. + * You can pass in multiple data structures, just end the function + * parameters with a NULL. + */ +int logdev_record(int id, int total_size, const void *data, int size, ...); +void logdev_dump(void); +void logdev_record_switch(struct task_struct *prev, struct task_struct *next); + +#define LOGDEV(x,y...) logdev_##x(y) +#define LOGPRINTS(func,x...) do { if (logdev_print_ison()) LOGDEV(func,x); } while(0) + +/* + * Using the UPPER case here ignores the logdev_print_enabled flag + */ +#define LOGPRINT(x...) LOGDEV(print,x) +#define LOGTPRINT(x...) LOGDEV(print_time,x) +#define LOGTFPRINT(x...) LOGDEV(print_time_func,__FUNCTION__,__LINE__,x) + +/* + * Using these functions, will only log if logdev_print_enabled flag is set. + */ + +#define lprint(x...) LOGPRINTS(print,x) +#define ltprint(x...) LOGPRINTS(print_time,x) +#define lfprint(x...) LOGPRINTS(print_time_func,__FUNCTION__,__LINE__,x) + +/* + * lfnprint is identical to lfprint except that it adds a new line at the end. + */ +#define _lnprint(func,x,y...) func( x "%s\n", y) +#define lnprint(x...) _lnprint(lprint,x,"") +#define ltnprint(x...) _lnprint(ltprint,x,"") +#define lfnprint(x...) _lnprint(lfprint,x,"") + +struct logdev_callback { + struct list_head list; + int id; + logdev_callback_func func; +}; + +int logdev_register_callback(int custom_id, logdev_callback_func func); +int logdev_unregister_callback(int custom_id); + +int logdev_init(void); /* If we want to put this in main.c */ + +#else /* !LOGDEV */ +#define logdev_dump() do {} while(0) +#define logdev_record(id, size, data) do {} while(0) +#define logdev_record_switch(prev, next) do {} while(0) + +#define LOGPRINT(x...) do {} while(0) +#define LOGTPRINT(x...) do {} while(0) +#define LOGTFPRINT(x...) do {} while(0) + +#define logdev_print_ison() ( 0 ) +#define logdev_print_on() do {} while(0) +#define logdev_print_off() do {} while(0) + +#define logdev_switch_ison() ( 0 ) +#define logdev_switch_on() do {} while(0) +#define logdev_switch_off() do {} while(0) + +#define logdev_print(x...) do {} while(0) + +#define lprint(x...) do {} while(0) +#define ltprint(x...) do {} while(0) +#define lfprint(x...) do {} while(0) + +#define lnprint(x...) do {} while(0) +#define ltnprint(x...) do {} while(0) +#define lfnprint(x...) do {} while(0) + +#define logdev_register_callback(i,f) do {} while(0) +#define logdev_unregister_callback(i) do {} while(0) +#define in_logdump 0 +#endif /* LOGDEV */ + +#endif Index: linux-2.6.21.5-rt20/lib/Kconfig.debug =================================================================== --- linux-2.6.21.5-rt20.orig/lib/Kconfig.debug 2007-07-11 10:09:49.000000000 +0200 +++ linux-2.6.21.5-rt20/lib/Kconfig.debug 2007-07-11 14:28:50.000000000 +0200 @@ -608,6 +608,76 @@ config FORCED_INLINING become the default in the future, until then this option is there to test gcc for this. +config LOGDEV + bool "Enable logdev device" + depends on DEBUG_KERNEL + help + The logdev device stores data into the kernel that can be retrieved + later through a misc device (major 10). The minor number is + dynamic and is posted through /proc/logdev/minor. Utilities + to open and read the device can be found at + http://rostedt.homelinux.com/logdev + + This device allows for tracing lots of information in the kernel + when simply printk is too expensive. When the logdev is initialized, + it allocates a default of 1 meg of memory (in page size units). This + allows for saving data in a ring buffer without the need to allocate. + +config LOGDEV_PROBE + bool + depends on LOGDEV && KPROBES + default y + +choice + prompt "Logdev Backend" + depends on LOGDEV + default LOGDEV_RINGBUF + +config LOGDEV_RINGBUF + bool "Logdev internal ring buffer" + ---help--- + Logdev needs a backend to store the data as it is logged. + this is done in memory, to record without much digression + in performance of machine. With this option logdev creates + its own simple memory ring buffer. This allows it to record + things really early in the boot process. + +config LOGDEV_RELAY + bool "Logdev with relayfs (BROKEN)" + ---help--- + Logdev needs a backend to store the data as it is logged. + this is done in memory, to record without much digression + in performance of machine. With this option logdev uses + relayfs as its back end. This makes it more standard to + other things in the kernel, and for userspace. + +endchoice + +config LOGDEV_PAGES + int "Number of pages to allocate for logdev device" + depends on LOGDEV + default 256 + help + The Logdev device allocates a number of pages for the sole + purpose of logging data. This is the number of pages that + the Logdev device should allocate upon loading / initializing. + +config LOGDEV_PRINT_ENABLED + bool "Default Logdev prints should be enabled on startup" + depends on LOGDEV + help + Enable this if you expect the LOGPRINT macros to be enabled + as soon as the logdev device is loaded. Otherwise you must + enable it with /proc/logdev/print + +config LOGDEV_SWITCH_ENABLED + bool "Default Logdev printing of context switches on startup" + depends on LOGDEV + help + Enable this if you expect the LOGSWITCH macros to be enabled + as soon as the logdev device is loaded. Otherwise you must + enable it with /proc/logdev/switch + config RCU_TORTURE_TEST tristate "torture tests for RCU" depends on DEBUG_KERNEL Index: linux-2.6.21.5-rt20/arch/i386/kernel/traps.c =================================================================== --- linux-2.6.21.5-rt20.orig/arch/i386/kernel/traps.c 2007-07-11 10:09:49.000000000 +0200 +++ linux-2.6.21.5-rt20/arch/i386/kernel/traps.c 2007-07-11 14:28:50.000000000 +0200 @@ -31,6 +31,7 @@ #include #include #include +#include #ifdef CONFIG_EISA #include @@ -790,6 +791,7 @@ void __kprobes die_nmi(struct pt_regs *r printk(" on CPU%d, eip %08lx, registers:\n", smp_processor_id(), regs->eip); show_registers(regs); + logdev_dump(); console_silent(); spin_unlock(&nmi_print_lock); bust_spinlocks(0); Index: linux-2.6.21.5-rt20/drivers/char/sysrq.c =================================================================== --- linux-2.6.21.5-rt20.orig/drivers/char/sysrq.c 2007-07-11 10:09:49.000000000 +0200 +++ linux-2.6.21.5-rt20/drivers/char/sysrq.c 2007-07-11 14:28:50.000000000 +0200 @@ -30,6 +30,7 @@ #include #include #include /* for fsync_bdev() */ +#include #include #include #include @@ -181,6 +182,39 @@ static struct sysrq_key_op sysrq_mountro .enable_mask = SYSRQ_ENABLE_REMOUNT, }; +static void sysrq_handle_dumplog(int key, struct tty_struct *tty) +{ + logdev_dump(); +} + +static struct sysrq_key_op sysrq_dumplog_op = { + .handler = sysrq_handle_dumplog, + .help_msg = "Dumplog", + .action_msg = "Dump logdev to serial", +}; + +static void sysrq_handle_togglelogswitch(int key, struct tty_struct *tty) +{ + /* + * Not so atomic, but we really don't care! + */ + if (logdev_switch_ison()) { + logdev_switch_off(); + printk("logdev_switch now off\n"); + } else { + logdev_switch_on(); + printk("logdev_switch now on\n"); + } +} + +static struct sysrq_key_op sysrq_togglelogdevswitch_op = { + .handler = sysrq_handle_togglelogswitch, + .help_msg = "Togglelogswitch", + .action_msg = "Toggling logdev_switch", +}; + +/* END SYNC SYSRQ HANDLERS BLOCK */ + #ifdef CONFIG_LOCKDEP static void sysrq_handle_showlocks(int key, struct tty_struct *tty) { @@ -350,9 +384,9 @@ static struct sysrq_key_op *sysrq_key_ta &sysrq_crashdump_op, /* c & ibm_emac driver debug */ &sysrq_showlocks_op, /* d */ &sysrq_term_op, /* e */ - &sysrq_moom_op, /* f */ + &sysrq_togglelogdevswitch_op, /* f */ /* g: May be registered by ppc for kgdb */ - NULL, /* g */ + &sysrq_dumplog_op, /* g */ NULL, /* h */ &sysrq_kill_op, /* i */ NULL, /* j */ @@ -373,7 +407,7 @@ static struct sysrq_key_op *sysrq_key_ta &sysrq_showstate_blocked_op, /* w */ /* x: May be registered on ppc/powerpc for xmon */ NULL, /* x */ - NULL, /* y */ + &sysrq_moom_op, /* y */ NULL /* z */ }; Index: linux-2.6.21.5-rt20/arch/i386/mm/fault.c =================================================================== --- linux-2.6.21.5-rt20.orig/arch/i386/mm/fault.c 2007-07-11 10:09:49.000000000 +0200 +++ linux-2.6.21.5-rt20/arch/i386/mm/fault.c 2007-07-11 14:28:50.000000000 +0200 @@ -29,6 +29,7 @@ #include #include +#include extern void die(const char *,struct pt_regs *,long); static ATOMIC_NOTIFIER_HEAD(notify_page_fault_chain); @@ -519,6 +520,8 @@ no_context: bust_spinlocks(1); if (oops_may_print()) { + lfnprint("BUG!"); + logdev_print_off(); #ifdef CONFIG_X86_PAE if (error_code & 16) { pte_t *pte = lookup_address(address); Index: linux-2.6.21.5-rt20/kernel/Makefile =================================================================== --- linux-2.6.21.5-rt20.orig/kernel/Makefile 2007-07-11 10:09:49.000000000 +0200 +++ linux-2.6.21.5-rt20/kernel/Makefile 2007-07-11 14:28:50.000000000 +0200 @@ -64,6 +64,7 @@ obj-$(CONFIG_SYSCTL) += utsname_sysctl.o obj-$(CONFIG_UTS_NS) += utsname.o obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o +obj-$(CONFIG_LOGDEV) += logdev/ ifneq ($(CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER),y) # According to Alan Modra , the -fno-omit-frame-pointer is Index: linux-2.6.21.5-rt20/kernel/logdev/Makefile =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ linux-2.6.21.5-rt20/kernel/logdev/Makefile 2007-07-11 14:28:50.000000000 +0200 @@ -0,0 +1,7 @@ + +obj-y := logdev.o + +obj-$(CONFIG_LOGDEV_PROBE) += logdev_probe.o +obj-$(CONFIG_LOGDEV_RINGBUF) += logdev_ringbuf.o +obj-$(CONFIG_LOGDEV_RELAY) += logdev_relay.o + Index: linux-2.6.21.5-rt20/kernel/logdev/logdev.c =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ linux-2.6.21.5-rt20/kernel/logdev/logdev.c 2007-07-11 14:28:50.000000000 +0200 @@ -0,0 +1,1269 @@ +/* + * logdev.c + * + * Copyright (C) 2004-2006 Steven Rostedt, Kihon Technologies, Inc. + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License (not later!) + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + */ +#undef CONFIG_CRITICAL_IRQSOFF_TIMING /* ignore this for this whole file! */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#include "logdev_priv.h" + +static char *logdev_version = "0.5.4"; + +/* used for BUG(), since we can't add any headers in that file */ +int get_processor_id(void) { return smp_processor_id(); } +EXPORT_SYMBOL(get_processor_id); + +void log_show_eip(const char *func) +{ + lfnprint("(%s) from %p",func,__builtin_return_address(0)); +} + +/* bit mask of logdev settings (only one bit used so far) */ +unsigned long logdev_switches; +EXPORT_SYMBOL_GPL(logdev_switches); + +/* Compares good for a difference of ~2 billion. */ +static inline int compare_cnt(unsigned long a, unsigned long b) +{ + long x = (long)a - (long)b; + return x > 0 ? 1 : x < 0 ? -1 : 0; +} + +static atomic_t logdev_counter = ATOMIC_INIT(0); +#define logdev_counter_inc() atomic_inc_return(&logdev_counter); + +DEFINE_PER_CPU(struct logdev_dev, logdev_dev); + +/* + * We don't support hotplug CPUS + */ +#define check_cpu(cpu) ({ \ + static int once = 1; \ + int x; \ + if (unlikely(x = (cpu >= LOGDEV_CPUS)) && once) { \ + once = 0; \ + printk("BUG %s:%d: cpu %d doesn't fit logdev cpus\n", \ + __FILE__, __LINE__, cpu); \ + } \ + x; \ + }) + +int logdev_copy_from_dev(struct logdev_dev *dev, void *buf, + int size); +int logdev_copy_to_dev(struct logdev_dev *dev, const void *dat, + int size); + +static int option_logdev_print(char *opt) +{ + logdev_print_on(); + return 0; +} + +static int option_logdev_switch(char *opt) +{ + logdev_switch_on(); + return 0; +} + +__setup("logdevprint", option_logdev_print); +__setup("logdevswitch", option_logdev_switch); + +/* + * The following is to register call back functions to print out + * a custom record. + */ + +DEFINE_SPINLOCK(logdev_callbacks_lock); + +LIST_HEAD(logdev_callbacks); +EXPORT_SYMBOL_GPL(logdev_callbacks); + +int __kprobes logdev_register_callback(int custom_id, + logdev_callback_func func) +{ + struct list_head *p; + struct logdev_callback *cb; + unsigned long flags; + int ret = 0; + + cb = kmalloc(sizeof(*cb),GFP_KERNEL); + if (!cb) { + ret = -ENOMEM; + goto out; + } + + spin_lock_irqsave(&logdev_callbacks_lock, flags); + list_for_each(p,&logdev_callbacks) { + struct logdev_callback *c = + list_entry(p, struct logdev_callback, list); + if (c->id == custom_id) { + spin_unlock_irqrestore(&logdev_callbacks_lock,flags); + kfree(cb); + ret = -EBUSY; + goto out; + } + } + + cb->id = custom_id; + cb->func = func; + list_add(&cb->list, &logdev_callbacks); + spin_unlock_irqrestore(&logdev_callbacks_lock, flags); + + out: + return ret; +} + +int __kprobes logdev_unregister_callback(int custom_id) +{ + struct list_head *p; + struct logdev_callback *cb; + unsigned long flags; + int ret = 0; + + spin_lock_irqsave(&logdev_callbacks_lock, flags); + list_for_each(p,&logdev_callbacks) { + cb = list_entry(p, struct logdev_callback, list); + if (cb->id == custom_id) + break; + } + if (p == &logdev_callbacks) { + ret = -ENODEV; + spin_unlock_irqrestore(&logdev_callbacks_lock,flags); + goto out; + } + + list_del(&cb->list); + spin_unlock_irqrestore(&logdev_callbacks_lock, flags); + + kfree(cb); + + out: + return ret; +} + +/* + * We have a separate kernel buffer for each CPU. + * This buffer is used to copy snprintf data into the ring buffer. + */ +static char kern_buffer[LOGDEV_CPUS][PAGE_SIZE]; + +/* + * logdev_record_switch is used to track context switches. + * + * If the logdev_switch is not set, then this doesn't record. Thus allowing + * you to just record the context switches that are needed to record. + * Just use logdev_switch_on and logdev_switch_off to turn on this function. + * + * This is called from schedule, and interrupts should already be turned off. + */ +void __kprobes logdev_record_switch(struct task_struct *prev, + struct task_struct *next) +{ + struct logdev_dev *dev; + struct logdev_header hdr; + struct logdev_switch_struct rs; + int cpu = smp_processor_id(); + + if (!logdev_switch_ison()) + return; + + if (check_cpu(cpu)) + return; + + dev = get_logdev(cpu); + if (!dev_running(dev)) + return; + + WARN_ON(!irqs_disabled()); + + rs.t = sched_clock(); + rs.pid_prev = prev->pid; + rs.prev_prio = prev->prio; + rs.prev_static_prio = prev->static_prio; + rs.prev_normal_prio = prev->normal_prio; + rs.prev_state = prev->state; + rs.pid_next = next->pid; + rs.next_prio = next->prio; + rs.next_static_prio = next->static_prio; + rs.next_normal_prio = next->normal_prio; + memcpy(rs.prev_comm, prev->comm, TASK_COMM_LEN); + memcpy(rs.next_comm, next->comm, TASK_COMM_LEN); + + hdr.counter = logdev_counter_inc(); + hdr.id = LOGDEV_SWITCH_ID; + hdr.size = sizeof(hdr) + sizeof(rs); + + spin_lock(&dev->lock); + logdev_copy_to_dev(dev,&hdr,sizeof(hdr)); + logdev_copy_to_dev(dev,&rs,sizeof(rs)); + spin_unlock(&dev->lock); +} + +/* + * logdev_print acts like printk but it writes to the logdev device instead + * of a console. + */ +int __kprobes logdev_vprint(const char *str, va_list va) +{ + struct logdev_dev *dev; + char *buffer; + int len=0; + struct logdev_header hdr; + struct logdev_print rs; + unsigned long flags; + int cpu; + + local_irq_save(flags); + + cpu = smp_processor_id(); + + if (check_cpu(cpu)) + goto out; + + dev = get_logdev(cpu); + if (!dev_running(dev)) + goto out; + + buffer = kern_buffer[cpu]; + len = vsnprintf(buffer, PAGE_SIZE, str, va); + + if (len >= PAGE_SIZE) { + buffer[PAGE_SIZE-1] = 0; + len = PAGE_SIZE; + } + + hdr.counter = logdev_counter_inc(); + hdr.id = LOGDEV_PRINT; + hdr.size = sizeof(hdr) + sizeof(rs) + len; + + spin_lock(&dev->lock); + logdev_copy_to_dev(dev, &hdr, sizeof(hdr)); + if (sizeof(rs)) + logdev_copy_to_dev(dev, &rs, sizeof(rs)); + logdev_copy_to_dev(dev, buffer, len); + spin_unlock(&dev->lock); + + out: + local_irq_restore(flags); + + return len; +} + +int __kprobes logdev_print(const char *str, ...) +{ + va_list va; + struct logdev_dev *dev; + char *buffer; + int len=0; + struct logdev_header hdr; + struct logdev_print rs; + unsigned long flags; + int cpu; + + local_irq_save(flags); + + cpu = smp_processor_id(); + + if (check_cpu(cpu)) + goto out; + + dev = get_logdev(cpu); + if (!dev_running(dev)) + goto out; + + buffer = kern_buffer[cpu]; + + va_start(va,str); + len = vsnprintf(buffer, PAGE_SIZE, str, va); + va_end(va); + + if (len >= PAGE_SIZE) { + buffer[PAGE_SIZE-1] = 0; + len = PAGE_SIZE; + } + + hdr.counter = logdev_counter_inc(); + hdr.id = LOGDEV_PRINT; + hdr.size = sizeof(hdr) + sizeof(rs) + len; + + spin_lock(&dev->lock); + logdev_copy_to_dev(dev, &hdr, sizeof(hdr)); + if (sizeof(rs)) + logdev_copy_to_dev(dev, &rs, sizeof(rs)); + logdev_copy_to_dev(dev, buffer, len); + spin_unlock(&dev->lock); + + out: + local_irq_restore(flags); + + return len; +} + +/* + * logdev_print_time is the same as logdev_print but it attaches a timestamp + * to it. Saves on doing it yourself. + */ +int __kprobes logdev_print_time(const char *str, ...) +{ + struct logdev_dev *dev; + char *buffer; + va_list va; + int len = 0; + struct logdev_header hdr; + struct logdev_print_time rs; + unsigned long flags; + int cpu; + + local_irq_save(flags); + + cpu = smp_processor_id(); + + if (check_cpu(cpu)) + goto out; + + dev = get_logdev(cpu); + if (!dev_running(dev)) + goto out; + + buffer = kern_buffer[cpu]; + + va_start(va,str); + len = vsnprintf(buffer, PAGE_SIZE, str, va); + va_end(va); + + if (len >= PAGE_SIZE) { + buffer[PAGE_SIZE-1] = 0; + len = PAGE_SIZE; + } + + rs.t = sched_clock(); + + hdr.counter = logdev_counter_inc(); + hdr.id = LOGDEV_PRINT_TIME; + hdr.size = sizeof(hdr) + sizeof(rs) + len; + + spin_lock(&dev->lock); + logdev_copy_to_dev(dev, &hdr, sizeof(hdr)); + logdev_copy_to_dev(dev, &rs, sizeof(rs)); + logdev_copy_to_dev(dev, buffer, len); + spin_unlock(&dev->lock); + + out: + local_irq_restore(flags); + + return len; +} + +/* + * logdev_print_time_func quickly stores the time, function and line number. + * this is really only good for live runs since the function is just a pointer, + * so a user land process would need to have the System.map available. + */ +int __kprobes logdev_print_time_func(const char *file, int line, + const char *str, ...) +{ + struct logdev_dev *dev; + char *buffer; + va_list va; + int len = 0; + struct logdev_header hdr; + struct logdev_print_time_func rs; + unsigned long flags; + int cpu; + + local_irq_save(flags); + + cpu = smp_processor_id(); + + if (check_cpu(cpu)) + goto out; + + dev = get_logdev(cpu); + if (!dev_running(dev)) + goto out; + + buffer = kern_buffer[cpu]; + + va_start(va,str); + len = vsnprintf(buffer, PAGE_SIZE, str, va); + va_end(va); + + if (len >= PAGE_SIZE) { + buffer[PAGE_SIZE-1] = 0; + len = PAGE_SIZE; + } + + rs.t = sched_clock(); + rs.file = file; + rs.line = line; + + hdr.counter = logdev_counter_inc(); + hdr.id = LOGDEV_PRINT_TIME_FUNC; + hdr.size = sizeof(hdr) + sizeof(rs) + len; + + spin_lock(&dev->lock); + logdev_copy_to_dev(dev, &hdr, sizeof(hdr)); + logdev_copy_to_dev(dev, &rs, sizeof(rs)); + logdev_copy_to_dev(dev, buffer, len); + spin_unlock(&dev->lock); + + out: + local_irq_restore(flags); + + return len; +} + +/* + * If you feel like recording your own data, you can use logdev_record. + * just pass your own id, size and data. The size is the size of + * the data being passed and not the size actually being written to the + * device. + * That is already calculated. + * + * This record will be added as LOGDEV_CUSTOM and the given id will be the + * custom id. + * + * We use total_size so that we can avoid multiple copies to get the data + * into the buffer. + */ +int __kprobes logdev_record(int id, int total_size, const void *data, + int size, ...) +{ + struct logdev_dev *dev; + struct logdev_header hdr; + struct logdev_custom rs; + unsigned long flags; + int tsize = size; + int cpu; + int ret = 0; + va_list ap; + + if (!data) + return -EINVAL; + + local_irq_save(flags); + + cpu = smp_processor_id(); + + if (check_cpu(cpu)) + goto out; + + dev = get_logdev(cpu); + if (!dev_running(dev)) + goto out; + + hdr.counter = logdev_counter_inc(); + hdr.id = LOGDEV_CUSTOM; + hdr.size = sizeof(hdr) + sizeof(rs) + total_size; + + rs.id = id; + + spin_lock(&dev->lock); + logdev_copy_to_dev(dev, &hdr, sizeof(hdr)); + logdev_copy_to_dev(dev, &rs, sizeof(rs)); + va_start(ap, size); + do { + ret = logdev_copy_to_dev(dev, data, size); + if (tsize > total_size) + break; + data = va_arg(ap, void *); + if (data) { + size = va_arg(ap, int); + tsize += size; + if (tsize > total_size) + size -= tsize - total_size; + } + } while (data); + va_end(ap); + + /* + * If total_size didn't equal all sizes, then write padding. + */ + while (tsize < total_size) { + int cnt = total_size - tsize; + if (cnt > PAGE_SIZE) + cnt = PAGE_SIZE; + logdev_copy_to_dev(dev, kern_buffer[cpu], cnt); + tsize += cnt; + } + + spin_unlock(&dev->lock); + +out: + local_irq_restore(flags); + + return ret; +} + +/* + * If you just want to write into the buffer using your own methods, then this + * is perfectly fine. Just pass in your data and the size of the data being + * passed in. You can read it out later with logdev_record_read. But you wont + * have the benefits of keeping integrity when the buffer overflows. + */ +int __kprobes logdev_record_write(const char *data, int size) +{ + struct logdev_dev *dev; + int ret; + unsigned long flags; + int cpu; + + local_irq_save(flags); + + cpu = smp_processor_id(); + dev = get_logdev(cpu); + if (!dev_running(dev)) { + local_irq_restore(flags); + return 0; + } + + spin_lock(&dev->lock); + ret = logdev_copy_to_dev(dev, data, size); + spin_unlock(&dev->lock); + local_irq_restore(flags); + + return ret; +} + +/* + * logdev_record_read reads some data from the logdev device no matter what + * it was. + */ +int __kprobes logdev_record_read(void *data, int size) +{ + struct logdev_dev *dev; + int ret; + unsigned long flags; + int cpu; + + local_irq_save(flags); + + cpu = smp_processor_id(); + dev = get_logdev(cpu); + if (!dev_running(dev)) { + local_irq_restore(flags); + return 0; + } + + spin_lock(&dev->lock); + ret = logdev_copy_from_dev(dev, data, size); + spin_unlock(&dev->lock); + local_irq_restore(flags); + + return ret; +} + +/* + * sched_clock isn't exported, so we export it ourselves. + */ + +int in_logdump; +EXPORT_SYMBOL_GPL(in_logdump); + +static int __kprobes get_next_cpus(struct logdev_header *hdr, + int *_this_cpu, int *_next_cpu) +{ + int cpu; + int f = 0; + struct logdev_dev *dev; + int this_cpu = -1; + int next_cpu = -1; + int last_cpu = 1; + + for_each_present_cpu(cpu) { + + if (cpu >= LOGDEV_CPUS) + break; + + dev = get_logdev(cpu); + if (!dev_suspended(dev)) + continue; + + /* Skip empty buffers */ + if (hdr[cpu].id == LOGDEV_HDR_DONE) + continue; + + /* + * If the header is corrupted, just pick it + * as if this buffer was the last. The corruption + * will break out of the loop in the flush. + */ + if (!logdev_valid(hdr[cpu].id)) { + this_cpu = cpu; + next_cpu = -1; + last_cpu = 1; + break; + } + + /* + * If this is the first cpu, then use it, otherwise, + * compare. + */ + if (!f || + compare_cnt(hdr[cpu].counter, + hdr[this_cpu].counter) < 0) { + if (!f) + f = 1; + else { + /* we already have the first count */ + next_cpu = this_cpu; + last_cpu = 0; + f = 2; + } + this_cpu = cpu; + } else if (f == 1 || + compare_cnt(hdr[cpu].counter, + hdr[next_cpu].counter) < 0) { + f = 2; + next_cpu = cpu; + last_cpu = 0; + } + } + + *_this_cpu = this_cpu; + *_next_cpu = next_cpu; + + return last_cpu; +} + +static int __kprobes process_log(struct logdev_dev *dev, + struct logdev_header *hdr, + int cpu) +{ + int i; + int r; + int count; + int corrupt = 0; + int line = 0; + int newline = 1; + unsigned long long t; + unsigned long usec_rem; + unsigned long secs; + const char *file = NULL; + + r = sizeof(hdr[0]); + + switch (hdr[cpu].id) { + + case LOGDEV_PRINT_TIME_FUNC: + { + struct logdev_print_time_func rs; + int cap = sizeof(rs) - sizeof(struct logdev_print_time); + + logdev_copy_from_dev(dev, &rs, cap); + file = rs.file; + line = rs.line; + + r += cap; + + /* fall through */ + } + + case LOGDEV_PRINT_TIME: + { + struct logdev_print_time rs; + + logdev_copy_from_dev(dev, &rs, sizeof(rs)); + + if (newline) { + t = rs.t; + usec_rem = do_div(t, 1000000000)/1000; + secs = (unsigned long)t; + + printk("[%5lu.%06lu] ", + secs, usec_rem); + } + + r += sizeof(rs); + + /* fall through */ + } + + case LOGDEV_PRINT: + if (newline) { + printk("cpu:%d ",cpu); + + if (hdr[cpu].id == LOGDEV_PRINT_TIME_FUNC) + printk("%s:%d ",file, line); + } + for (i=r; i < hdr[cpu].size; i += r) { + count = hdr[cpu].size - i; + if (count > PAGE_SIZE-1) + count = PAGE_SIZE-1; + r = logdev_copy_from_dev(dev, kern_buffer[cpu], count); + if (r < 0) + break; + kern_buffer[cpu][count] = 0; + printk("%s", kern_buffer[cpu]); + newline = (count) && + (kern_buffer[cpu][count - 1] != '\n') ? 0 : 1; + } + break; + + case LOGDEV_SWITCH_ID: + { + struct logdev_switch_struct rs; + + printk(">>>> IN LOGDEV SWITCH <<<< cpu:%d \n", cpu); + + logdev_copy_from_dev(dev,&rs,sizeof(rs)); + + t = rs.t; + usec_rem = do_div(t, 1000000000)/1000; + secs = (unsigned long)t; + + printk("CPU=%d [%5lu.%06lu] ", + cpu, secs,usec_rem); + + printk("%s:%d(%d:%d:%d) -->> ", + rs.prev_comm, + rs.pid_prev, + rs.prev_prio, + rs.prev_static_prio, + rs.prev_normal_prio); + + printk("%s:%d(%d:%d:%d)\n", + rs.next_comm, + rs.pid_next, + rs.next_prio, + rs.next_static_prio, + rs.next_normal_prio); + + break; + } + + case LOGDEV_CUSTOM: + { + struct list_head *p; + struct logdev_custom custom; + int len; + + logdev_copy_from_dev(dev,&custom,sizeof(custom)); + + spin_lock(&logdev_callbacks_lock); + i = len = hdr[cpu].size - sizeof(hdr[0]) - sizeof(custom); + if (i > PAGE_SIZE) + i = PAGE_SIZE; + + /* change size to be what the record size is. */ + hdr[cpu].size = i; + + logdev_copy_from_dev(dev,kern_buffer[cpu],i); + + list_for_each(p, &logdev_callbacks) { + struct logdev_callback *cb = + list_entry(p, struct logdev_callback, list); + if (cb->id == custom.id) { + cb->func(&hdr[cpu], &custom, cpu, + kern_buffer[cpu]); + break; + } + } + + /* No record should be bigger than a page. Ignore all else */ + while (i < len) { + int count = len - i; + if (count > PAGE_SIZE) + count = PAGE_SIZE; + logdev_copy_from_dev(dev,kern_buffer[cpu],count); + i += count; + } + + /* check if we didn't find a call back */ + if (p == &logdev_callbacks) { + printk("skipping! LOGDEV_CUSTOM id %d\n",custom.id); + } + + spin_unlock(&logdev_callbacks_lock); + break; + } + default: + corrupt = 1; + if (!dev->corrupted) { + dev->corrupted = 1; + printk(">>>>> Unknown logdev header, cpu %d buffer " + "may be corrupted from this point on\n", cpu); + } else + printk("CPU %d >>> corrupted header <<<\n", cpu); + break; + } + + return corrupt; +} + +static int __kprobes flush_buffer(struct logdev_dev *dev, + struct logdev_header *hdr, + int cpu, int next_cpu, int last_cpu) +{ + int corrupt = 0; + int more_work = 1; + + while (last_cpu || compare_cnt(hdr[cpu].counter, + hdr[next_cpu].counter) <= 0) { + + BUG_ON(hdr[cpu].id == LOGDEV_HDR_DONE); + + /* + * Lets not set off watchdogs. + */ + touch_nmi_watchdog(); + + corrupt = process_log(dev, hdr, cpu); + + /* Read the next header for this */ + if ((logdev_copy_from_dev(dev,&hdr[cpu],sizeof(hdr[0]))) + != sizeof(hdr[0])) { + hdr[cpu].id = LOGDEV_HDR_DONE; + if (last_cpu) + more_work = 0; + break; + } + /* + * if we have a corrupted header, then stop this buffer flush. + */ + if (corrupt) + break; + } + + return more_work; +} + +void __kprobes logdev_dump(void) +{ + int save_switch; + int save_print; + struct logdev_dev *dev; + struct logdev_header hdr[LOGDEV_CPUS]; + static int started = 0; + int do_lock = 1; + extern int in_logdump; + unsigned long flags; + int more_work = 0; + int cpu; + + /* + * We don't care about race conditions with this started variable. + * It only exists to keep dumps a little cleaner. If two dumps get + * through at the same time, it doesn't hurt. + */ + if (started) + return; + + started = 1; + + /* + * Because of the started race, we also use in_logdump just for + * reference. + */ + in_logdump++; + + if (oops_in_progress) + do_lock = 0; + + local_irq_save(flags); + + /* + * This is for debugging, so we don't want to reintroduce more output. + */ + save_switch = logdev_switch_ison(); + save_print = logdev_print_ison(); + logdev_switch_off(); + logdev_print_off(); + + printk("****** Starting Logdev Dump ********\n"); + + /* + * Read all the available headers for each CPU. + */ + for_each_present_cpu(cpu) { + + if (cpu >= LOGDEV_CPUS) + break; + + dev = get_logdev(cpu); + if (!dev_running(dev)) + continue; + + if (dev->corrupted) { + printk("Warning buffer for CPU %d is corrupted\n", + cpu); + /* will be set when corrupted part is read. */ + dev->corrupted = 0; + } + + /* + * Long time to hold the spin locks, but hey it's just + * debugging. + */ + spin_lock(&dev->lock); + + /* + * Try to limit the amount added while reading + * this buffer, suspend the buffer. (redundant but also good + * for accounting) + */ + dev->init = LOGDEV_DEV_SUSPENDED; + + if ((logdev_copy_from_dev(dev, &hdr[cpu], sizeof(hdr[0]))) + == sizeof(hdr[0])) + /* record that we have a buffer to work with. */ + more_work = 1; + else + /* record that the buffer is empty */ + hdr[cpu].id = LOGDEV_HDR_DONE; + } + + while (more_work) { + int this_cpu; + int next_cpu; + int last_cpu; + + /* + * Find the cpu to work with that has the earliest counter, + * and also the cpu with the next counter. + */ + last_cpu = get_next_cpus(hdr, &this_cpu, &next_cpu); + + cpu = this_cpu; + dev = get_logdev(cpu); + + BUG_ON(this_cpu < 0); + BUG_ON(!last_cpu && next_cpu < 0); + BUG_ON(dev->init != LOGDEV_DEV_SUSPENDED); + BUG_ON(hdr[cpu].id == LOGDEV_HDR_DONE); + + /* + * Now print out all from this buffer until we reach + * the next cpu. If this is the last buffer to write + * then finish the buffer. + */ + more_work = flush_buffer(dev, hdr, cpu, next_cpu, last_cpu); + } + + printk( ">>>>> done <<<<<\n"); + + for_each_present_cpu(cpu) { + if (cpu >= LOGDEV_CPUS) + break; + dev = get_logdev(cpu); + if (dev_suspended(dev)) { + dev->init = LOGDEV_DEV_RUNNING; + /* buffers should be emptied */ + dev->corrupted = 0; + spin_unlock(&dev->lock); + } + + } + if (save_print) + logdev_print_on(); + if (save_switch) + logdev_switch_on(); + + local_irq_restore(flags); + started = 0; + in_logdump--; +} + +static int __kprobes logdev_panic_handler(struct notifier_block *this, + unsigned long event, + void *unused) +{ + logdev_dump(); + return NOTIFY_OK; +} + +static struct notifier_block logdev_panic_notifier = { + .notifier_call = logdev_panic_handler, + .next = NULL, + .priority = 150 /* priority: INT_MAX >= x >= 0 */ +}; + +/* + * Unfortunately, the die handlers have no way to unregister, so + * we don't want to do this if we are a module. We would if we could + * find a way to clean ourselves up when unloaded. + */ +int __kprobes logdev_die_handler(struct notifier_block *self, + unsigned long val, + void *data) +{ + switch (val) { + case DIE_OOPS: + logdev_dump(); + break; + default: + break; + } + return NOTIFY_OK; +} + +static struct notifier_block logdev_die_notifier = { + .notifier_call = logdev_die_handler, + .priority = 200 +}; + +static int logdev_open_generic(struct inode *inode, struct file *filp) +{ + filp->private_data = inode->i_private; + return 0; +} + + +static ssize_t logdev_debug_sw_read(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + long bit = (long)(filp->private_data); + char buf[16]; + int var = !!(logdev_switches & (1<private_data); + char buf[16]; + + /* We control what bit is, so it had better be right! */ + if (bit >= LOGDEV_SW_BITS) + BUG(); + + bit = (1 << bit); + + if (cnt > 15) + cnt = 15; + + if(copy_from_user(&buf, ubuf, cnt)) + return -EFAULT; + + buf[cnt] = 0; + + val = simple_strtoul(buf, NULL, 10) ? bit : 0; + + logdev_switches = (logdev_switches & ~bit) | val; + + filp->f_pos += cnt; + + return cnt; +} + +static struct file_operations logdev_debug_sw_fops = { + .open = logdev_open_generic, + .read = logdev_debug_sw_read, + .write = logdev_debug_sw_write, +}; + +static ssize_t logdev_debug_read(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + unsigned long *data = filp->private_data; + char buf[16]; + int r; + + r = sprintf(buf, "%0lx\n", *data); + return simple_read_from_buffer(ubuf, cnt, ppos, + buf, r); +} + +static ssize_t logdev_debug_write(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + unsigned long *data = filp->private_data; + char buf[10]; + unsigned long val; + + if (cnt > 9) + cnt = 9; + + if(copy_from_user(&buf, ubuf, cnt)) + return -EFAULT; + + buf[cnt] = 0; + + val = simple_strtoul(buf, NULL, 10); + + *data = val; + + filp->f_pos += cnt; + + return cnt; +} + +static struct file_operations logdev_debug_rdonly_fops = { + .open = logdev_open_generic, + .read = logdev_debug_read, +}; + +static struct file_operations logdev_debug_rdwr_fops = { + .open = logdev_open_generic, + .read = logdev_debug_read, + .read = logdev_debug_write, +}; + +struct dentry *logdev_d; +EXPORT_SYMBOL_GPL(logdev_d); + +static int logdev_debugfs_init(void) +{ + struct dentry *d_switches; + struct dentry *d_switch; + struct dentry *d_print; +#ifndef CONFIG_LOGDEV_MARKER + struct dentry *d_mark; +#endif + + logdev_d = debugfs_create_dir("logdev", NULL); + if (!logdev_d) { + printk("can't create logdev debugfs\n"); + return 0; + } + if (logdev_d == ERR_PTR(-ENODEV)) { + printk("debugfs not configured in. Can't access logdev " + "from userspace\n"); + logdev_d = NULL; + return 0; + } + + d_switches = debugfs_create_file("switches", 0444, logdev_d, + &logdev_switches, + &logdev_debug_rdonly_fops); + d_switch = debugfs_create_file("switch", 0644, logdev_d, + (void*)LOGDEV_SW_SWITCH_ENABLED, + &logdev_debug_sw_fops); + d_print = debugfs_create_file("print", 0644, logdev_d, + (void*)LOGDEV_SW_PRINT_ENABLED, + &logdev_debug_sw_fops); +#ifndef CONFIG_LOGDEV_MARKER + d_mark = debugfs_create_file("mark", 0644, logdev_d, + (void*)LOGDEV_SW_MARKER_ENABLED, + &logdev_debug_sw_fops); +#endif + return 0; +} + +extern void logdev_cleanup_priv(struct logdev_dev *dev); + +static void __exit logdev_cleanup(void) +{ + struct logdev_dev *dev; + int i; + + atomic_notifier_chain_unregister(&panic_notifier_list, + &logdev_panic_notifier); + + for (i=0; i < LOGDEV_CPUS; i++) { + dev = get_logdev(i); + logdev_cleanup_priv(dev); + } +} + +extern int initialize_logdev(void); + +int __init logdev_init(void) +{ + int res = 0; + int cpu; + struct logdev_dev *dev; + static int init = 0; + + if (init) + return 0; + + init = 1; + + printk("Logdevice: copyright Steven Rostedt, Kihon Technologies Inc." + " (Version %s)\n", + logdev_version); + + for_each_present_cpu(cpu) { + + if (cpu >= LOGDEV_CPUS) { + printk(KERN_WARNING "More present cpus (%d) than " + "NR_CPUS (%d)\n", + cpu,LOGDEV_CPUS); + break; + } + + printk("Initializing logdev for cpu: %d\n",cpu); + + dev = get_logdev(cpu); + spin_lock_init(&dev->lock); + dev->init = LOGDEV_DEV_UP; + } + + if (initialize_logdev() < 0) + goto fail; + + atomic_notifier_chain_register(&panic_notifier_list, + &logdev_panic_notifier); + + register_die_notifier(&logdev_die_notifier); + + res = 0; + +#ifdef CONFIG_LOGDEV_PRINT_ENABLED + logdev_print_on(); +#endif +#ifdef CONFIG_LOGDEV_SWITCH_ENABLED + logdev_switch_on(); +#endif + +out: + return res; + +fail: + logdev_cleanup(); + goto out; +} + +EXPORT_SYMBOL_GPL(logdev_record_switch); +EXPORT_SYMBOL_GPL(logdev_print); +EXPORT_SYMBOL_GPL(logdev_print_time); +EXPORT_SYMBOL_GPL(logdev_print_time_func); +EXPORT_SYMBOL_GPL(logdev_record); +EXPORT_SYMBOL_GPL(logdev_record_write); +EXPORT_SYMBOL_GPL(logdev_record_read); +EXPORT_SYMBOL_GPL(logdev_dump); + +core_initcall(logdev_init); +postcore_initcall(logdev_debugfs_init); Index: linux-2.6.21.5-rt20/kernel/logdev/logdev_priv.h =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ linux-2.6.21.5-rt20/kernel/logdev/logdev_priv.h 2007-07-11 14:28:50.000000000 +0200 @@ -0,0 +1,52 @@ +#ifndef _LOG_DEV_PRIV_H +#define _LOG_DEV_PRIV_H + +/* Random numbers out of my head used for MAGIC */ +#define LOGDEV_CUSTOM 0x1afb +#define LOGDEV_SWITCH_ID 0x2afc +#define LOGDEV_PRINT 0x4adb +#define LOGDEV_PRINT_TIME 0x4adc +#define LOGDEV_PRINT_TIME_FUNC 0x4add +#define LOGDEV_HDR_DONE 0xbbbb /* internal use only */ + +static inline int logdev_valid(int id) +{ + switch (id) { + case LOGDEV_CUSTOM: + case LOGDEV_SWITCH_ID: + case LOGDEV_PRINT: + case LOGDEV_PRINT_TIME: + case LOGDEV_PRINT_TIME_FUNC: + return 1; + } + return 0; +} + +struct logdev_dev { + int init; + int corrupted; + spinlock_t lock; + void *priv; +}; + +DECLARE_PER_CPU(struct logdev_dev, logdev_dev); +#define get_logdev(cpu) &per_cpu(logdev_dev, cpu) + +#define LOGDEV_CPUS NR_CPUS + +#define LOGDEV_DEV_UNINITALIZED 0 +#define LOGDEV_DEV_RUNNING 1 +#define LOGDEV_DEV_SUSPENDED 2 +#define LOGDEV_DEV_UP 3 + +#define dev_running(dev) ((dev)->init == LOGDEV_DEV_RUNNING) +#define dev_suspended(dev) ((dev)->init == LOGDEV_DEV_SUSPENDED) +#define dev_up(dev) ((dev)->init == LOGDEV_DEV_UP) + +extern struct dentry *logdev_d; + +#ifdef CONFIG_LOGDEV_RINGBUF +#include "logdev_ringbuf.h" +#endif + +#endif Index: linux-2.6.21.5-rt20/kernel/logdev/logdev_probe.c =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ linux-2.6.21.5-rt20/kernel/logdev/logdev_probe.c 2007-07-11 14:28:50.000000000 +0200 @@ -0,0 +1,1310 @@ +/* + * logdev_probe.c + * + * Copyright (C) 2004-2006 Steven Rostedt + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License (not later!) + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#include "logdev_priv.h" + +#undef DPRINTK +#if 1 +# define DPRINTK(x...) printk(x) +#else +# define DPRINTK(x...) do { } while(0) +#endif + +static atomic_t logdev_probe_next_id = ATOMIC_INIT(1); +static DEFINE_MUTEX(probe_list_lock); +enum logprobe_type { + LOGPROBE_BP, + LOGPROBE_FUNC, + LOGPROBE_CURR, + LOGPROBE_VAR, +}; + +static char *logdev_probe_buffer; +static int logdev_probe_buffer_sz; +static DEFINE_SPINLOCK(probe_buffer_lock); +static DEFINE_PER_CPU(struct jprobe *, jprobe); + +/* ---------------- cut here for user space headers -------------------- */ + +/* "s/user_//" for the below when bringing to user space */ + +#define LOGPROBE_IOCTL_BASE 'l' + +#define PROBE_IOW(nr, type) _IOW(LOGPROBE_IOCTL_BASE, nr, type) + +#define LOGPROBE_DELPOINT PROBE_IOW(0, unsigned long) +#define LOGPROBE_ADDWATCH PROBE_IOW(1, struct user_logdev_probe_watch) +#define LOGPROBE_ADDFUNC PROBE_IOW(2, struct user_logdev_probe_func) +#define LOGPROBE_ADDCURR PROBE_IOW(3, struct user_logdev_probe_curr) +#define LOGPROBE_ADDVAR PROBE_IOW(4, struct user_logdev_probe_var) + +#define LOGPROBE_ID_WATCH 0x56570001 +#define LOGPROBE_ID_FUNC 0x56570002 +#define LOGPROBE_ID_CURR 0x56570003 +#define LOGPROBE_ID_VAR 0x56570004 + +#define LOGPROBE_TYPE_PREEMPT 0x1111 + +struct logdev_probe_hdr_log { + unsigned long long t; + char comm[TASK_COMM_LEN]; + int pid; + unsigned long addr; + unsigned long offset; + int func_symbol_size; +}; + +struct logdev_probe_watch_log { + struct logdev_probe_hdr_log hdr; + unsigned long var; + unsigned long value; + int var_symbol_size; + char symbols[]; +}; + +struct logdev_probe_func_log { + struct logdev_probe_hdr_log hdr; + int str_size; + char symbols[]; +}; + +struct logdev_probe_curr_log { + struct logdev_probe_hdr_log hdr; + int index; + unsigned long value; + int prefix_size; + char symbols[]; +}; + +struct logdev_probe_var_log { + struct logdev_probe_hdr_log hdr; + int type; + unsigned long value; + int prefix_size; + char symbols[]; +}; + +struct user_logdev_probe_watch { + unsigned long addr; + unsigned long watch; + const char *func; + const char *var; + int func_size; + int var_size; +}; + +struct user_logdev_probe_func { + const char *func; + const char *fmt1; + const char *fmt2; + int func_size; + int fmt1_size; + int fmt2_size; +}; + +struct user_logdev_probe_curr { + unsigned long addr; + const char *func; + const char *prefix; + int offset; + int func_size; + int prefix_size; +}; + +struct user_logdev_probe_var { + unsigned long addr; + const char *func; + const char *prefix; + int type; + int func_size; + int prefix_size; +}; + +/* ---------------- end of user space cut ---------------- */ + +struct logdev_probe_hdr { + unsigned long addr; + unsigned long offset; + int func_symbol_size; + char func_symbol[KSYM_NAME_LEN+1]; +}; + +struct logdev_probe_watch { + struct logdev_probe_hdr hdr; + struct kprobe kp; + unsigned long var; + int var_symbol_size; + char var_symbol[KSYM_NAME_LEN+1]; +}; + +struct logdev_probe_func { + struct logdev_probe_hdr hdr; + struct jprobe jp; + const char *fmt1; + const char *fmt2; +}; + +struct logdev_probe_curr { + struct logdev_probe_hdr hdr; + struct kprobe kp; + int index; + char *prefix; + int prefix_size; +}; + +struct logdev_probe_var { + struct logdev_probe_hdr hdr; + struct kprobe kp; + int type; + char *prefix; + int prefix_size; +}; + +struct logdev_probe { + struct list_head list; + unsigned long id; + enum logprobe_type type; + union { + struct logdev_probe_watch watch; + struct logdev_probe_func func; + struct logdev_probe_curr curr; + struct logdev_probe_var var; + }; +}; + +static LIST_HEAD(logdev_probes); + +static void logdev_print_time_cpu(unsigned long long t, int cpu) +{ + unsigned long usec_rem; + unsigned long secs; + + usec_rem = do_div(t, 1000000000)/1000; + secs = (unsigned long)t; + + printk("[%5lu.%06lu] cpu:%d ", + secs, usec_rem, cpu); +} + +/* + * This is called under a lock, so we can use a static buffer. + */ +static char probe_buf[PAGE_SIZE]; + +/* ------------------- cut here for user space print -------------- */ + +/* "s/printk/printf" */ + +static const char *logdev_print_symbol(const char *sym, int size) +{ + /* we don't trust not having a null char */ + while (size) { + int sz = size; + if (sz > PAGE_SIZE-1) + sz = PAGE_SIZE-1; + memcpy(probe_buf, sym, sz); + probe_buf[sz] = 0; + printk("%s", probe_buf); + sym += sz; + size -= sz; + } + + return sym; +} + +static const char * logdev_print_hdr(int cpu, + const char *sym, + struct logdev_probe_hdr_log *hdr) +{ + logdev_print_time_cpu(hdr->t, cpu); + + memcpy(probe_buf, hdr->comm, TASK_COMM_LEN); + probe_buf[TASK_COMM_LEN] = 0; + printk("%s:%d ", probe_buf, hdr->pid); + + printk("func: "); + sym = logdev_print_symbol(sym, hdr->func_symbol_size); + printk(" (%p) ", (void*)hdr->addr); + + return sym; +} + +static void logdev_probe_watch_print(int cpu, int size, + struct logdev_probe_watch_log *lp) +{ + const char *sym; + + if (size < sizeof(*lp) || + size != sizeof(*lp) + lp->var_symbol_size + + lp->hdr.func_symbol_size) { + printk("CPU[%d] Bad probe var record!\n", + cpu); + return; + } + + sym = logdev_print_hdr(cpu, lp->symbols, &lp->hdr); + + if (lp->var) { + printk("var: "); + sym = logdev_print_symbol(sym, lp->var_symbol_size); + printk(" (%p) = %08lx", + (void*)lp->var, + lp->value); + } + printk("\n"); + +} + +static void logdev_probe_func_print(int cpu, int size, + struct logdev_probe_func_log *lp) +{ + const char *sym; + + if (size < sizeof(*lp) || + size != sizeof(*lp) + lp->hdr.func_symbol_size + + lp->str_size) { + printk("CPU[%d] Bad probe func record!\n", + cpu); + return; + } + + sym = logdev_print_hdr(cpu, lp->symbols, &lp->hdr); + + if (lp->str_size) + logdev_print_symbol(sym, lp->str_size); + + printk("\n"); + +} + +static void logdev_probe_curr_print(int cpu, int size, + struct logdev_probe_curr_log *lp) +{ + const char *sym; + + if (size < sizeof(*lp) || + size != sizeof(*lp) + lp->hdr.func_symbol_size + + lp->prefix_size) { + printk("CPU[%d] Bad probe curr record!\n", + cpu); + return; + } + + sym = logdev_print_hdr(cpu, lp->symbols, &lp->hdr); + + if (lp->prefix_size) + logdev_print_symbol(sym, lp->prefix_size); + + printk(" index:%d = %p", lp->index, (void*)lp->value); + + printk("\n"); + +} + +static void logdev_probe_var_print(int cpu, int size, + struct logdev_probe_var_log *lp) +{ + const char *sym; + + if (size < sizeof(*lp) || + size != sizeof(*lp) + lp->hdr.func_symbol_size + + lp->prefix_size) { + printk("CPU[%d] Bad probe curr record!\n", + cpu); + return; + } + + sym = logdev_print_hdr(cpu, lp->symbols, &lp->hdr); + + switch (lp->type) { + case LOGPROBE_TYPE_PREEMPT: + printk(" preempt_count:"); + break; + } + + if (lp->prefix_size) + logdev_print_symbol(sym, lp->prefix_size); + + printk("0x%lx", lp->value); + + printk("\n"); + +} + +static void logdev_probe_callback(struct logdev_header *hdr, + struct logdev_custom *custom, + int cpu, + void *rec) +{ + switch (custom->id) { + case LOGPROBE_ID_WATCH: + logdev_probe_watch_print(cpu, hdr->size, rec); + break; + case LOGPROBE_ID_FUNC: + logdev_probe_func_print(cpu, hdr->size, rec); + break; + case LOGPROBE_ID_CURR: + logdev_probe_curr_print(cpu, hdr->size, rec); + break; + case LOGPROBE_ID_VAR: + logdev_probe_var_print(cpu, hdr->size, rec); + break; + default: + printk("Unknown probe callback id %x\n", + custom->id); + break; + } +} +/* ------------------ end cut for user space printing ------------------- */ + + +/************************ Kprobes ******************************/ + +static void __kprobes logprobe_hdr(struct logdev_probe_hdr_log *lp, + struct logdev_probe_hdr *p) +{ + lp->t = sched_clock(); + memcpy(lp->comm, current->comm, TASK_COMM_LEN); + lp->pid = current->pid; + lp->addr = p->addr; + lp->offset = p->offset; + lp->func_symbol_size = p->func_symbol_size; +} + +static int __kprobes logprobe_watch(struct kprobe *kp, struct pt_regs *regs) +{ + struct logdev_probe_watch *p = + container_of(kp, struct logdev_probe_watch, kp); + struct logdev_probe_watch_log lp; + int total_sz = sizeof(lp) + p->var_symbol_size + + p->hdr.func_symbol_size; + + rcu_read_lock(); + + logprobe_hdr(&lp.hdr, &p->hdr); + + lp.var = p->var; + if (p->var) + lp.value = *(unsigned long*)(p->var); + lp.var_symbol_size = p->var_symbol_size; + logdev_record(LOGPROBE_ID_WATCH, total_sz, + &lp, sizeof(lp), + p->hdr.func_symbol, p->hdr.func_symbol_size, + p->var_symbol, p->var_symbol_size, + NULL); + + rcu_read_unlock(); + + return 0; +} + + +static asmlinkage long __kprobes logprobe_func(unsigned long param, ...) +{ + struct jprobe *jp; + struct logdev_probe_func *p; + struct logdev_probe_func_log lp; + va_list ap; + int total_sz; + unsigned long flags; + int i = -1; + + if (!logdev_probe_buffer) + jprobe_return(); + + jp = __get_cpu_var(jprobe); + if (!jp) + jprobe_return(); + + p = container_of(jp, struct logdev_probe_func, jp); + + /* find probe */ + rcu_read_lock(); + + logprobe_hdr(&lp.hdr, &p->hdr); + + spin_lock_irqsave(&probe_buffer_lock, flags); + if (p->fmt1) { + i = snprintf(logdev_probe_buffer, logdev_probe_buffer_sz, + p->fmt1, param); + + if (p->fmt2 && i < logdev_probe_buffer_sz) { + va_start(ap, param); + i += snprintf(logdev_probe_buffer + i, + logdev_probe_buffer_sz - i, + p->fmt2, ap); + va_end(ap); + } + if (i > logdev_probe_buffer_sz) + i = logdev_probe_buffer_sz; + + logdev_probe_buffer[i] = 0; + } + + lp.str_size = i+1; + + total_sz = sizeof(lp) + lp.hdr.func_symbol_size + lp.str_size; + + logdev_record(LOGPROBE_ID_FUNC, total_sz, + &lp, sizeof(lp), + p->hdr.func_symbol, p->hdr.func_symbol_size, + logdev_probe_buffer, lp.str_size, + NULL); + spin_unlock_irqrestore(&probe_buffer_lock, flags); + + rcu_read_unlock(); + + jprobe_return(); + /* NOT REACHED */ + return 0; +} + + +static int __kprobes logprobe_curr(struct kprobe *kp, struct pt_regs *regs) +{ + struct logdev_probe_curr *p = + container_of(kp, struct logdev_probe_curr, kp); + struct logdev_probe_curr_log lp; + int total_sz = sizeof(lp) + p->prefix_size + + p->hdr.func_symbol_size; + unsigned long *ptr; + + rcu_read_lock(); + + logprobe_hdr(&lp.hdr, &p->hdr); + + lp.index = p->index; + + ptr = (unsigned long*)((char*)current + p->index); + lp.value = *ptr; + + lp.prefix_size = p->prefix_size; + + logdev_record(LOGPROBE_ID_CURR, total_sz, + &lp, sizeof(lp), + p->hdr.func_symbol, p->hdr.func_symbol_size, + p->prefix, p->prefix_size, + NULL); + + rcu_read_unlock(); + + return 0; +} + +static int __kprobes logprobe_var(struct kprobe *kp, struct pt_regs *regs) +{ + struct logdev_probe_var *p = + container_of(kp, struct logdev_probe_var, kp); + struct logdev_probe_var_log lp; + int total_sz = sizeof(lp) + p->prefix_size + + p->hdr.func_symbol_size; + unsigned long pc = preempt_count(); + + rcu_read_lock(); + + logprobe_hdr(&lp.hdr, &p->hdr); + + lp.type = p->type; + + switch(lp.type) { + case LOGPROBE_TYPE_PREEMPT: + lp.value = pc; + default: + lp.value = 0; + } + + lp.prefix_size = p->prefix_size; + + logdev_record(LOGPROBE_ID_VAR, total_sz, + &lp, sizeof(lp), + p->hdr.func_symbol, p->hdr.func_symbol_size, + p->prefix, p->prefix_size, + NULL); + + rcu_read_unlock(); + + return 0; +} + +/*********************** end Kprobes **************************/ + +static int __kprobes logdev_probe_update_hdr(struct logdev_probe_hdr *p) +{ + const char *sym; + unsigned long size; + char *modname; + + if (p->addr) { + sym = kallsyms_lookup(p->addr, &size, &p->offset, &modname, + p->func_symbol); + if (sym) + p->func_symbol_size = strlen(sym); + } else { + size = strlen(p->func_symbol); + p->func_symbol_size = size; + p->addr = kallsyms_lookup_name(p->func_symbol); + if (!p->addr) { + DPRINTK("func name %s not found", p->func_symbol); + return -EINVAL; + } + } + + return 0; +} + +static int __kprobes logdev_probe_add_watch(struct logdev_probe *lh) +{ + struct logdev_probe_watch *p = &lh->watch; + const char *sym; + char *modname; + unsigned long size; + unsigned long offset; + unsigned long watch = p->var; + int ret; + + lh->type = LOGPROBE_BP; + + DPRINTK("set up watch\n"); + /* can only have one or the other */ + if (p->hdr.func_symbol[0] && p->hdr.addr) + return -EINVAL; + if (p->var_symbol[0] && watch) + return -EINVAL; + + DPRINTK("passed first test\n"); + /* TBD: check upper limit ?? */ + if (!p->hdr.func_symbol[0] && p->hdr.addr < PAGE_OFFSET) + return -EINVAL; + + DPRINTK("passed second test\n"); + /* + * kallsyms requires no scheduling. + */ + preempt_disable(); + ret = logdev_probe_update_hdr(&p->hdr); + if (ret) { + preempt_enable(); + return ret; + } + + if (watch) { + sym = kallsyms_lookup(watch, &size, &offset, &modname, + p->var_symbol); + if (sym) + p->var_symbol_size = strlen(sym); + } else if (p->var_symbol) { + size = strlen(p->var_symbol); + p->var_symbol_size = size; + watch = kallsyms_lookup_name(p->var_symbol); + if (!watch) { + DPRINTK("var name %s not found", p->var_symbol); + preempt_enable(); + return -EINVAL; + } + } + preempt_enable(); + + p->var = watch; + p->kp.pre_handler = logprobe_watch; + p->kp.addr = (kprobe_opcode_t *)p->hdr.addr; + + ret = register_kprobe(&p->kp); + if (ret < 0) + return ret; + + lh->id = atomic_inc_return(&logdev_probe_next_id); + + return lh->id; +} + +/* Hijack the jprobes registering! */ + +static int __kprobes logdev_setjmp_pre_handler(struct kprobe *p, + struct pt_regs *regs) +{ + __get_cpu_var(jprobe) = container_of(p, struct jprobe, kp); + return setjmp_pre_handler(p, regs); +} + +static int __kprobes logdev_longjmp_break_handler(struct kprobe *p, + struct pt_regs *regs) +{ + int ret; + ret = longjmp_break_handler(p, regs); + __get_cpu_var(jprobe) = NULL; + return ret; +} + +static int logdev_register_jprobe(struct jprobe *jp) +{ + jp->kp.pre_handler = logdev_setjmp_pre_handler; + jp->kp.break_handler = logdev_longjmp_break_handler; + + return register_kprobe(&jp->kp); +} + +static int __kprobes logdev_probe_add_func(struct logdev_probe *lh, + const char *fmt1, + const char *fmt2) +{ + struct logdev_probe_func *p = &lh->func; + int ret; + + lh->type = LOGPROBE_FUNC; + + /* + * kallsyms requires no scheduling. + */ + preempt_disable(); + + ret = logdev_probe_update_hdr(&p->hdr); + preempt_enable(); + + if (ret) + return ret; + + p->fmt1 = fmt1; + p->fmt2 = fmt2; + p->jp.entry = (kprobe_opcode_t *)logprobe_func; + p->jp.kp.addr = (kprobe_opcode_t *)p->hdr.addr; + + ret = logdev_register_jprobe(&p->jp); + if (ret < 0) + return ret; + + lh->id = atomic_inc_return(&logdev_probe_next_id); + + return lh->id; +} + +static int __kprobes logdev_probe_add_curr(struct logdev_probe *lh) +{ + struct logdev_probe_curr *p = &lh->curr; + int ret; + + lh->type = LOGPROBE_CURR; + + /* + * kallsyms requires no scheduling. + */ + preempt_disable(); + ret = logdev_probe_update_hdr(&p->hdr); + preempt_enable(); + if (ret) + return ret; + + p->kp.pre_handler = logprobe_curr; + p->kp.addr = (kprobe_opcode_t *)p->hdr.addr; + + ret = register_kprobe(&p->kp); + if (ret < 0) + return ret; + + lh->id = atomic_inc_return(&logdev_probe_next_id); + + return lh->id; +} + +static int __kprobes logdev_probe_add_var(struct logdev_probe *lh) +{ + struct logdev_probe_var *p = &lh->var; + int ret; + + lh->type = LOGPROBE_VAR; + + /* + * kallsyms requires no scheduling. + */ + preempt_disable(); + ret = logdev_probe_update_hdr(&p->hdr); + preempt_enable(); + if (ret) + return ret; + + p->kp.pre_handler = logprobe_var; + p->kp.addr = (kprobe_opcode_t *)p->hdr.addr; + + ret = register_kprobe(&p->kp); + if (ret < 0) + return ret; + + lh->id = atomic_inc_return(&logdev_probe_next_id); + + return lh->id; +} + +/************************ User Land ******************************/ + +static int logdev_setup_probe_watch(unsigned long __user *arg) +{ + struct user_logdev_probe_watch *uprobe; + struct logdev_probe *lh = NULL; + struct logdev_probe_watch *probe; + int ret; + + uprobe = kmalloc(sizeof(*uprobe), GFP_KERNEL); + + if (!uprobe) + return -ENOMEM; + + ret = -EFAULT; + if(copy_from_user(uprobe, arg, sizeof(*uprobe))) + goto fail; + + ret = -ENOMEM; + lh = kzalloc(sizeof(*lh), GFP_KERNEL); + if (!lh) + goto fail; + + probe = &lh->watch; + + ret = -EFAULT; + if (uprobe->func) { + if (uprobe->func_size > KSYM_NAME_LEN) + uprobe->func_size = KSYM_NAME_LEN; + if (copy_from_user(probe->hdr.func_symbol, uprobe->func, + uprobe->func_size)) + goto fail; + } + if (uprobe->var) { + if (uprobe->var_size > KSYM_NAME_LEN) + uprobe->var_size = KSYM_NAME_LEN; + if (copy_from_user(probe->var_symbol, uprobe->var, + uprobe->var_size)) + goto fail; + } + probe->hdr.addr = uprobe->addr; + probe->var = uprobe->watch; + + ret = logdev_probe_add_watch(lh); + if (ret < 0) + goto fail; + + mutex_lock(&probe_list_lock); + list_add_tail_rcu(&lh->list, &logdev_probes); + mutex_unlock(&probe_list_lock); + + return ret; + + fail: + if (uprobe) + kfree(uprobe); + if (lh) + kfree(lh); + return ret; +} + +static int logdev_setup_probe_func(unsigned long __user *arg) +{ + struct user_logdev_probe_func *uprobe; + struct logdev_probe *lh = NULL; + struct logdev_probe_func *probe; + char *fmt1 = NULL; + char *fmt2 = NULL; + int ret; + + uprobe = kmalloc(sizeof(*uprobe), GFP_KERNEL); + + if (!uprobe) + return -ENOMEM; + + ret = -EFAULT; + if(copy_from_user(uprobe, arg, sizeof(*uprobe))) + goto fail; + + ret = -EINVAL; + if (!uprobe->func || !uprobe->func_size) + goto fail; + + ret = -ENOMEM; + lh = kzalloc(sizeof(*lh), GFP_KERNEL); + if (!lh) + goto fail; + + probe = &lh->func; + + ret = -EFAULT; + if (uprobe->func_size > KSYM_NAME_LEN) + uprobe->func_size = KSYM_NAME_LEN; + if (copy_from_user(probe->hdr.func_symbol, uprobe->func, + uprobe->func_size)) + goto fail; + + if (uprobe->fmt1 && uprobe->fmt1_size) { + ret = -ENOMEM; + fmt1 = kmalloc(uprobe->fmt1_size+1, GFP_KERNEL); + if (!fmt1) + goto fail; + ret = -EFAULT; + if (copy_from_user(fmt1, uprobe->fmt1, + uprobe->fmt1_size)) + goto fail; + fmt1[uprobe->fmt1_size] = 0; + + if (uprobe->fmt2 && uprobe->fmt2_size) { + ret = -ENOMEM; + fmt2 = kmalloc(uprobe->fmt2_size+1, GFP_KERNEL); + if (!fmt2) + goto fail; + ret = -EFAULT; + if (copy_from_user(fmt2, uprobe->fmt2, + uprobe->fmt2_size)) + goto fail; + fmt2[uprobe->fmt2_size] = 0; + } + } + + ret = logdev_probe_add_func(lh, fmt1, fmt2); + if (ret < 0) + goto fail; + + mutex_lock(&probe_list_lock); + list_add_tail_rcu(&lh->list, &logdev_probes); + mutex_unlock(&probe_list_lock); + + return ret; + + fail: + DPRINTK("%s FAILED\n",__FUNCTION__); + if (fmt1) + kfree(fmt1); + if (fmt2) + kfree(fmt2); + if (uprobe) + kfree(uprobe); + if (lh) + kfree(lh); + return ret; +} + +static int logdev_setup_probe_curr(unsigned long __user *arg) +{ + struct user_logdev_probe_curr *uprobe; + struct logdev_probe *lh = NULL; + struct logdev_probe_curr *probe; + int ret; + + uprobe = kmalloc(sizeof(*uprobe), GFP_KERNEL); + + if (!uprobe) + return -ENOMEM; + + ret = -EFAULT; + if(copy_from_user(uprobe, arg, sizeof(*uprobe))) + goto fail; + + ret = -ENOMEM; + lh = kzalloc(sizeof(*lh), GFP_KERNEL); + if (!lh) + goto fail; + + probe = &lh->curr; + + ret = -EFAULT; + if (uprobe->func) { + if (uprobe->func_size > KSYM_NAME_LEN) + uprobe->func_size = KSYM_NAME_LEN; + if (copy_from_user(probe->hdr.func_symbol, uprobe->func, + uprobe->func_size)) + goto fail; + } + /* yes this can be negative! */ + probe->index = uprobe->offset; + + if (uprobe->prefix && uprobe->prefix_size > 0) { + probe->prefix = kmalloc(uprobe->prefix_size + 1, GFP_KERNEL); + if (copy_from_user(probe->prefix, uprobe->prefix, + uprobe->prefix_size)) + goto fail; + probe->prefix[uprobe->prefix_size] = 0; + probe->prefix_size = uprobe->prefix_size + 1; + } + probe->hdr.addr = uprobe->addr; + + ret = logdev_probe_add_curr(lh); + if (ret < 0) + goto fail; + + mutex_lock(&probe_list_lock); + list_add_tail_rcu(&lh->list, &logdev_probes); + mutex_unlock(&probe_list_lock); + + return ret; + + fail: + if (uprobe) + kfree(uprobe); + if (lh) + kfree(lh); + return ret; +} + +static int logdev_setup_probe_var(unsigned long __user *arg) +{ + struct user_logdev_probe_var *uprobe; + struct logdev_probe *lh = NULL; + struct logdev_probe_var *probe; + int ret; + + uprobe = kmalloc(sizeof(*uprobe), GFP_KERNEL); + + if (!uprobe) + return -ENOMEM; + + ret = -EFAULT; + if(copy_from_user(uprobe, arg, sizeof(*uprobe))) + goto fail; + + ret = -ENOMEM; + lh = kzalloc(sizeof(*lh), GFP_KERNEL); + if (!lh) + goto fail; + + probe = &lh->var; + + probe->type = uprobe->type; + switch(probe->type) { + case LOGPROBE_TYPE_PREEMPT: + break; + default: + ret = -EINVAL; + goto fail; + } + + ret = -EFAULT; + if (uprobe->func) { + if (uprobe->func_size > KSYM_NAME_LEN) + uprobe->func_size = KSYM_NAME_LEN; + if (copy_from_user(probe->hdr.func_symbol, uprobe->func, + uprobe->func_size)) + goto fail; + } + + if (uprobe->prefix && uprobe->prefix_size > 0) { + probe->prefix = kmalloc(uprobe->prefix_size + 1, GFP_KERNEL); + if (copy_from_user(probe->prefix, uprobe->prefix, + uprobe->prefix_size)) + goto fail; + probe->prefix[uprobe->prefix_size] = 0; + probe->prefix_size = uprobe->prefix_size + 1; + } + probe->hdr.addr = uprobe->addr; + + ret = logdev_probe_add_var(lh); + if (ret < 0) + goto fail; + + mutex_lock(&probe_list_lock); + list_add_tail_rcu(&lh->list, &logdev_probes); + mutex_unlock(&probe_list_lock); + + return ret; + + fail: + if (uprobe) + kfree(uprobe); + if (lh) + kfree(lh); + return ret; +} + +static int logdev_probe_ioctl(struct inode *inode, struct file *filp, + unsigned int cmd, unsigned long arg) +{ + int ret = 0; + + switch (cmd) { + case LOGPROBE_ADDWATCH: + + ret = logdev_setup_probe_watch((unsigned long __user *)arg); + + break; + + case LOGPROBE_ADDFUNC: + + ret = logdev_setup_probe_func((unsigned long __user *)arg); + + break; + + case LOGPROBE_ADDCURR: + + ret = logdev_setup_probe_curr((unsigned long __user *)arg); + + break; + + case LOGPROBE_ADDVAR: + + ret = logdev_setup_probe_var((unsigned long __user *)arg); + + break; + + case LOGPROBE_DELPOINT: + { + struct logdev_probe *lp; + unsigned long id = arg; + + mutex_lock(&probe_list_lock); + list_for_each_entry_rcu(lp, &logdev_probes, list) + if (lp->id == id) + break; + if (&lp->list != &logdev_probes) + list_del_rcu(&lp->list); + else + lp = NULL; + mutex_unlock(&probe_list_lock); + + if (!lp) + return -EINVAL; + + switch (lp->type) { + case LOGPROBE_BP: + unregister_kprobe(&lp->watch.kp); + synchronize_rcu(); + break; + case LOGPROBE_FUNC: + unregister_jprobe(&lp->func.jp); + synchronize_rcu(); + + if (lp->func.fmt1) + kfree(lp->func.fmt1); + if (lp->func.fmt2) + kfree(lp->func.fmt2); + break; + case LOGPROBE_CURR: + unregister_kprobe(&lp->curr.kp); + synchronize_rcu(); + if (lp->curr.prefix) + kfree(lp->curr.prefix); + break; + case LOGPROBE_VAR: + unregister_kprobe(&lp->var.kp); + synchronize_rcu(); + if (lp->var.prefix) + kfree(lp->var.prefix); + break; + default: + printk(KERN_WARNING "unregistering logdev probe of" + "unknown type %d\n", + lp->type); + /* + * Don't even free this. We don't know where it + * is registered, and this is most certainly a bug! + */ + return -EINVAL; + } + + kfree(lp); + + break; + } + default: + ret = -ENOTTY; + } + + return ret; +} + + +/******************* List kprobe entries *****************/ + +static void __kprobes *s_next(struct seq_file *m, void *v, loff_t *pos) +{ + struct logdev_probe *p = NULL; + int l = 0; + + list_for_each_entry(p, &logdev_probes, list) { + if (l++ >= *pos) + break; + } + + (*pos)++; + + if (&p->list == &logdev_probes) + return NULL; + + return p; +} + +static void __kprobes *s_start(struct seq_file *m, loff_t *pos) + __acquires(logdev_dev.lock) +{ + struct logdev_probe *p = NULL; + loff_t l = 0; + + rcu_read_lock(); + + list_for_each_entry(p, &logdev_probes, list) { + if (l++ >= *pos) + break; + } + + if (&p->list == &logdev_probes) + return NULL; + + (*pos)++; + + return p; +} + +static void __kprobes s_stop(struct seq_file *m, void *p) + __releases(logdev_dev.lock) +{ + rcu_read_unlock(); +} + +static void hdr_show(struct seq_file *m, struct logdev_probe_hdr *p) +{ + seq_printf(m,"%s : %p\n", + p->func_symbol, + (void*)p->addr); +} + +static int __kprobes s_show(struct seq_file *m, void *v) +{ + struct logdev_probe *lh = v; + struct logdev_probe_watch *watch = &lh->watch; + struct logdev_probe_func *func = &lh->func; + struct logdev_probe_curr *curr = &lh->curr; + struct logdev_probe_var *var = &lh->var; + + seq_printf(m, "%ld:\t", lh->id); + switch (lh->type) { + case LOGPROBE_BP: + hdr_show(m, &watch->hdr); + if (watch->var) + seq_printf(m,"\t%s : %p\n", + watch->var_symbol, + (void*)watch->var); + break; + case LOGPROBE_FUNC: + hdr_show(m, &func->hdr); + if (func->fmt1) + seq_printf(m,"\tfmt1: %s\n", + func->fmt1); + if (func->fmt2) + seq_printf(m,"\tfmt2: %s\n", + func->fmt2); + break; + + case LOGPROBE_CURR: + hdr_show(m, &curr->hdr); + seq_printf(m,"\tindex: %d (0x%x)\n", + curr->index, curr->index); + if (curr->prefix) + seq_printf(m,"\tprefix: %s\n", + curr->prefix); + break; + + case LOGPROBE_VAR: + hdr_show(m, &var->hdr); + switch (var->type) { + case LOGPROBE_TYPE_PREEMPT: + seq_printf(m,"\tpreempt_count\n"); + break; + default: + seq_printf(m,"\tunknown type\n"); + } + if (curr->prefix) + seq_printf(m,"\tprefix: %s\n", + curr->prefix); + break; + + default: + seq_printf(m,"tunknown type %d\n", + lh->type); + } + return 0; +} + +static struct seq_operations logdev_seq_op = { + .start = s_start, + .next = s_next, + .stop = s_stop, + .show = s_show, +}; + +/******************* end list kprobes *****************/ + +static int logdev_probe_open (struct inode *inode, struct file *filp) +{ + int ret; + + ret = seq_open(filp, &logdev_seq_op); + if (!ret) { + struct seq_file *m = filp->private_data; + m->private = inode->i_private; + } + + return ret; +} + + +static struct file_operations logdev_probe_fops = { + .read = seq_read, + .ioctl = logdev_probe_ioctl, + .open = logdev_probe_open, + .llseek = seq_lseek, + .release = seq_release, +}; + +/************************ End User Land ******************************/ + + + +static int __init logdev_probe_init(void) +{ + debugfs_create_file("probe", 0600, logdev_d, + NULL, &logdev_probe_fops); + + logdev_register_callback(LOGPROBE_ID_WATCH, logdev_probe_callback); + logdev_register_callback(LOGPROBE_ID_FUNC, logdev_probe_callback); + logdev_register_callback(LOGPROBE_ID_CURR, logdev_probe_callback); + logdev_register_callback(LOGPROBE_ID_VAR, logdev_probe_callback); + + /* just some decent number */ + logdev_probe_buffer_sz = 256; + logdev_probe_buffer = kmalloc(logdev_probe_buffer_sz, GFP_KERNEL); + + /* If we fail, really no harm done */ + if (!logdev_probe_buffer) { + logdev_probe_buffer_sz = 0; + printk("logdev_probe: Warning, couldn't allocate func buffer\n"); + } + + return 0; +} + +module_init(logdev_probe_init); Index: linux-2.6.21.5-rt20/kernel/logdev/logdev_relay.c =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ linux-2.6.21.5-rt20/kernel/logdev/logdev_relay.c 2007-07-11 14:28:50.000000000 +0200 @@ -0,0 +1,175 @@ +/* + * logdev_relay.c + * + * Copyright (C) 2006 Tom Zanussi (zanussi@us.ibm.com), IBM Corp + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License (not later!) + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "logdev_priv.h" + +static int pages = CONFIG_LOGDEV_PAGES; + +/* + * Relay structures + */ +struct logdev_dev_priv { + int cpu; + struct rchan_buf *buf; + loff_t read_pos; +}; +DEFINE_PER_CPU(struct logdev_dev_priv, logdev_dev_priv); +#define get_logdev_priv(cpu) &per_cpu(logdev_dev_priv, cpu) + +static struct rchan *logdev_chan; + +DEFINE_PER_CPU(struct logdev_dev_priv, logdev_dev_priv); +#define get_logdev_priv(cpu) &per_cpu(logdev_dev_priv, cpu) + +int logdev_copy_from_dev(struct logdev_dev *ldev, void *buffer, int size) +{ + struct logdev_dev_priv *dev = ldev->priv; + struct rchan_buf *buf = dev->buf; + + return relay_kernel_read(buffer, size, &dev->read_pos, buf); +} + +int logdev_copy_to_dev(struct logdev_dev *ldev, const void *dat, + int size) +{ + struct logdev_dev_priv *dev = ldev->priv; + struct rchan_buf *buf = dev->buf; + + relay_write(buf->chan, dat, size); + + return size; +} + +static int logdev_subbuf_start(struct rchan_buf *buf, + void *subbuf, + void *prev_subbuf, + unsigned int prev_padding) +{ + return 1; +} + + +/* + * file_create() callback. Creates relay file in debugfs. + */ +static struct dentry *create_buf_file_handler(const char *filename, + struct dentry *parent, + int mode, + struct rchan_buf *buf, + int *is_global) +{ + struct dentry *buf_file; + + buf_file = debugfs_create_file(filename, mode, parent, buf, + &relay_file_operations); + + return buf_file; +} + +/* + * file_remove() default callback. Removes relay file in debugfs. + */ +static int remove_buf_file_handler(struct dentry *dentry) +{ + debugfs_remove(dentry); + + return 0; +} + +/* + * relay callbacks + */ +static struct rchan_callbacks logdev_relay_callbacks = +{ + .subbuf_start = logdev_subbuf_start, + .create_buf_file = create_buf_file_handler, + .remove_buf_file = remove_buf_file_handler, +}; + +int initialize_logdev(void) +{ + /* + * debugfs may not be ready when we initialize + * logdev. So postpone this later. + */ + return 0; +} + +void logdev_cleanup_priv(struct logdev_dev *ldev) +{ + if (logdev_chan) + relay_close(logdev_chan); +} + +int __init logdev_misc_init(void) +{ + struct logdev_dev *ldev; + struct logdev_dev_priv *dev; + struct rchan *chan; + int subbufs; + int cpu; + + /* round up */ + subbufs = (pages + 1) >> 1; + + chan = relay_open("dev", logdev_d, + PAGE_SIZE * 2, + subbufs, + &logdev_relay_callbacks); + if (!chan) + return -1; + + for_each_present_cpu(cpu) { + + if (cpu >= LOGDEV_CPUS) + break; + + ldev = get_logdev(cpu); + dev = get_logdev_priv(cpu); + dev->cpu = cpu; + ldev->priv = dev; + + dev->cpu = cpu; + dev->buf = chan->buf[cpu]; + ldev->init = LOGDEV_DEV_RUNNING; + } + + return 0; +} + +/* just needs to be after postcore init */ +arch_initcall(logdev_misc_init); + Index: linux-2.6.21.5-rt20/kernel/logdev/logdev_ringbuf.c =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ linux-2.6.21.5-rt20/kernel/logdev/logdev_ringbuf.c 2007-07-11 14:28:50.000000000 +0200 @@ -0,0 +1,482 @@ +/* + * logdev_ringbuf.c + * + * Copyright (C) 2004-2006 Steven Rostedt + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License (not later!) + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#include "logdev_priv.h" + +/* + * If need be, we can be placed really early before memory + * is locate, so if a flag is set, use bootmem otherwise use kmalloc. + * The earliest we can call logdev_init is just after smp_prepare_boot_cpu. + */ +#undef LOGDEV_USE_BOOTMEM + +static int pages = CONFIG_LOGDEV_PAGES; + +static void *logdev_malloc(int size) +{ +#ifndef LOGDEV_USE_BOOTMEM + return kmalloc(size, GFP_KERNEL); +#else + return alloc_bootmem(sizeof(int)); +#endif +} + +static void *logdev_get_free_pages(int order) +{ +#ifndef LOGDEV_USE_BOOTMEM + return (void*)__get_free_pages(GFP_KERNEL,order); +#else + return alloc_bootmem((1<private_data; + struct logdev_dev_priv *dev; + unsigned long flags; + + if (count > PAGE_SIZE) + count = PAGE_SIZE; + + if (mutex_lock_interruptible(&user_mutex)) + return -EINTR; + + if (!dev_running(ldev)) + goto out; + dev = ldev->priv; + + if (copy_from_user(user_buffer,buf,count)) { + count = -EFAULT; + goto out; + } + + spin_lock_irqsave(&ldev->lock,flags); + count = logdev_copy_to_dev(ldev,user_buffer,count); + spin_unlock_irqrestore(&ldev->lock,flags); + + /* wake up those waiting for data */ + if (waitqueue_active(&dev->wait)) + wake_up_interruptible(&dev->wait); + +out: + mutex_unlock(&user_mutex); + return count; +} + +ssize_t logdev_read(struct file *filp, char *buf, size_t count, loff_t *f_pos) +{ + struct logdev_dev *ldev = filp->private_data; + struct logdev_dev_priv *dev; + unsigned long flags; + + if (mutex_lock_interruptible(&user_mutex)) + return -EINTR; + + if (!dev_running(ldev)) + goto out_up; + + dev = ldev->priv; + + spin_lock_irqsave(&ldev->lock,flags); + + if (!dev->size) { + + /* TBD - FIXME */ +#if 1 + + count = 0; + goto out; +#endif + + if (filp->f_flags & O_NONBLOCK) { + count = -EAGAIN; + goto out; + } + + do { + DECLARE_WAITQUEUE(wait,current); + current->state = TASK_INTERRUPTIBLE; + add_wait_queue(&dev->wait,&wait); + spin_unlock_irqrestore(&ldev->lock,flags); + schedule(); + spin_lock_irqsave(&ldev->lock,flags); + remove_wait_queue(&dev->wait,&wait); + if (dev->size) + break; + if (signal_pending(current)) { + count = -ERESTARTSYS; + goto out; + } + } while(1); + } + + if (count > PAGE_SIZE) + count = PAGE_SIZE; + + + count = logdev_copy_from_dev(ldev,user_buffer,count); + + out: + /* We can't be corrupted if we have no data */ + if (!dev->size) + dev->corrupted = 0; + spin_unlock_irqrestore(&ldev->lock,flags); + + if (count > 0) { + /* Well if we fail here, we just lost the data read :-( */ + if (copy_to_user(buf,user_buffer,count)) + count = -EFAULT; + } + out_up: + mutex_unlock(&user_mutex); + + return count; +} + +static int logdev_ioctl(struct inode *inode, struct file *filp, + unsigned int cmd, unsigned long arg) +{ + return -ENOTTY; +} + +static int logdev_close(struct inode *inode, struct file *filp) +{ +#if 0 + int cpu = (int)filp->private_data; +#endif + return 0; +} + + +static int logdev_open (struct inode *inode, struct file *filp) +{ + filp->private_data = inode->i_private; + return 0; +} + +/** + * logdev_poll - poll file op for logdev + * @filp: the file + * @wait: poll table + * + * Poll implemention. + */ +static unsigned int +logdev_poll(struct file *filp, poll_table *wait) +{ + struct logdev_dev *dev = (struct logdev_dev*)filp->private_data; + unsigned int mask = 0; + + (void)dev; +#if 0 + if (filp->f_mode & FMODE_READ) { + poll_wait(filp, &app->read_wait, wait); + if (!empty_channel(dev)) + mask |= POLLIN | POLLRDNORM; + } +#endif + + return mask; +} + +static struct file_operations logdev_fops = { + .read = logdev_read, + .write = logdev_write, + .ioctl = logdev_ioctl, + .open = logdev_open, + .release = logdev_close, + .poll = logdev_poll, + .llseek = no_llseek, +}; + +/************************ End User Land ******************************/ + + +/******************* entry debugging interface *****************/ + +static void __kprobes *s_next(struct seq_file *m, void *v, loff_t *pos) +{ + struct logdev_dev *ldev = m->private; + struct logdev_dev_priv *dev = ldev->priv; + int i = (int)*pos; + + (*pos)++; + + if (i >= dev->len) + return NULL; + + return &dev->entry[i]; +} + +static void __kprobes *s_start(struct seq_file *m, loff_t *pos) + __acquires(logdev_dev.lock) +{ + struct logdev_dev *dev = m->private; + void *p = NULL; + loff_t l = 0; + + /* + * A little strong? Perhaps, but we know that this is bad right + * from the start. Anyway this is for debugging purposes only, + * so it's OK, as well as the big latency we get by turning off + * intrerrupts. But we also never know who will be locking + * this. + */ + if (irqs_disabled()) + BUG(); + + local_irq_disable(); + spin_lock(&dev->lock); + for (p = (void *)1; p && l < *pos; p = s_next(m,p,&l)) + ; + + return p; +} + +static void __kprobes s_stop(struct seq_file *m, void *p) + __releases(logdev_dev.lock) +{ + struct logdev_dev *dev = m->private; + spin_unlock(&dev->lock); + local_irq_enable(); +} + +static int __kprobes s_show(struct seq_file *m, void *v) +{ + int i = (long)(v); + struct logdev_entry *entry = v; + struct logdev_dev *ldev; + struct logdev_dev_priv *dev; + + ldev = m->private; + dev = ldev->priv; + + if (i == 1) { + seq_printf(m,"Logdev:\n"); + seq_printf(m,"\tlen:\t%d\n",dev->len); + seq_printf(m,"\tsize:\t%d\n",dev->size); + seq_printf(m,"\tstart:\t%d\n",dev->start); + seq_printf(m,"\tend:\t%d\n",dev->end); + seq_printf(m,"\tcorrupted:%d\n",dev->corrupted); + seq_printf(m,"\n\tEntries:\n"); + + } else { + i = (int)((char*)entry - (char*)dev->entry) / + sizeof(struct logdev_entry); + + seq_printf(m,"\t %d:\t%8u : %8u\tsize: %lu\n", i, + entry->head, entry->tail, + LOGDEV_ENTRY_SIZE(entry)); + } + + + return 0; +} + +static struct seq_operations logdev_proc_op = { + .start = s_start, + .next = s_next, + .stop = s_stop, + .show = s_show, +}; + +static int logdev_entries_open (struct inode *inode, struct file *file) +{ + int ret; + + ret = seq_open(file, &logdev_proc_op); + if (!ret) { + struct seq_file *m = file->private_data; + m->private = inode->i_private; + } + + return ret; +} + +static struct file_operations logdev_entries_fops = { + .open = logdev_entries_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +/******************* end entry debugging interface *****************/ + +int __init initialize_logdev(void) +{ + int cpu; + + for_each_present_cpu(cpu) { + struct logdev_dev *ldev; + struct logdev_dev_priv *dev; + struct logdev_entry *entry; + int i; + + ldev = get_logdev(cpu); + dev = get_logdev_priv(cpu); + dev->cpu = cpu; + ldev->priv = dev; + + dev->len = pages; + + dev->entry = + logdev_malloc(sizeof(struct logdev_entry)*dev->len); + if (!dev->entry) + return -ENOMEM; + + memset(dev->entry,0,sizeof(*dev->entry)*dev->len); + + for (i=0,entry=dev->entry; ilen; i++,entry++) { + entry->dat = logdev_get_free_pages(0); + if (!entry->dat) + return -ENOMEM; + } + init_waitqueue_head(&dev->wait); + + ldev->init = LOGDEV_DEV_RUNNING; + } + + return 0; +} + +void __init logdev_cleanup_priv(struct logdev_dev *ldev) +{ + struct logdev_dev_priv *dev = ldev->priv; + + if (!ldev->init) + return; + + if (dev->entry) { + struct logdev_entry *entry; + int i; + + for (i=0, entry=dev->entry; ilen; i++,entry++) + if (entry->dat) { + logdev_free_page((unsigned long)entry->dat); + entry->dat = NULL; + } + dev->len = 0; + logdev_kfree(dev->entry); + dev->entry = NULL; + ldev->init = 0; + } +} + +int __init logdev_misc_init(void) +{ + struct logdev_dev *ldev; + struct logdev_dev_priv *dev; + struct dentry *entries; + int cpu; + char buf[16]; + + if (!logdev_d) + return 0; + + entries = debugfs_create_dir("entry", logdev_d); + + for_each_present_cpu(cpu) { + + if (cpu >= LOGDEV_CPUS) + break; + + ldev = get_logdev(cpu); + if (!ldev->init) + continue; + + dev = ldev->priv; + + /* + * Setup the debugfs. + */ + sprintf(buf, "dev%d", cpu); + debugfs_create_file(buf, 0444, logdev_d, + ldev, &logdev_fops); + + if (entries) { + sprintf(buf,"%d",cpu); + debugfs_create_file(buf, 0444, entries, + ldev, &logdev_entries_fops); + } + } + + return 0; +} + +/* just needs to be after postcore init */ +arch_initcall(logdev_misc_init); Index: linux-2.6.21.5-rt20/kernel/logdev/logdev_ringbuf.h =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ linux-2.6.21.5-rt20/kernel/logdev/logdev_ringbuf.h 2007-07-11 14:28:50.000000000 +0200 @@ -0,0 +1,158 @@ +#ifndef __LINUX_LOGDEV_RINGBUF_H +#define __LINUX_LOGDEV_RINGBUF_H + +/* + * Ring buffer structures + */ +struct logdev_entry { + unsigned int head; + unsigned int tail; + char *dat; +}; + +struct logdev_dev_priv { + struct logdev_entry *entry; + int cpu; + int size; + int len; + int start; + int end; + int corrupted; + wait_queue_head_t wait; +}; + +DECLARE_PER_CPU(struct logdev_dev_priv, logdev_dev_priv); +#define get_logdev_priv(cpu) &per_cpu(logdev_dev_priv, cpu) + +#define LOGDEV_ENTRY_SIZE(e) ((((e)->tail - (e)->head)) & (PAGE_SIZE-1)) +#define LOGDEV_ENTRY_FREE(e) ((PAGE_SIZE-1) - LOGDEV_ENTRY_SIZE(e)) +#define LOGDEV_ENTRY_ADD(e,x) ((e) = ((e) + x) & (PAGE_SIZE-1)) +#define LOGDEV_ENTRY_INC(e) LOGDEV_ENTRY_ADD(e,1) +#define LOGDEV_ENTRY_MAX (PAGE_SIZE-1) + +static inline int logdev_copy_from_dev(struct logdev_dev *ldev, void *buf, + int size) +{ + struct logdev_dev_priv *dev = ldev->priv; + struct logdev_entry *entry = &dev->entry[dev->start]; + int ret = 0; + + if (size < 0) { + printk("logdev_copy_from_dev: size < 0 ???\n"); + return -1; + } + if (size > dev->size) + size = dev->size; + + while (size && dev->size) { + int copy = size; + int used; + + if (!LOGDEV_ENTRY_SIZE(entry)) { + dev->start = (dev->start + 1) % dev->len; + entry = &dev->entry[dev->start]; + } + + if (copy > (used=LOGDEV_ENTRY_SIZE(entry))) + copy = used; + if (entry->head+copy > PAGE_SIZE) + copy = PAGE_SIZE - entry->head; + memcpy(buf,entry->dat+entry->head,copy); + LOGDEV_ENTRY_ADD(entry->head,copy); + buf += copy; + dev->size -= copy; + size -= copy; + ret += copy; + + } + + return ret; +} + +static inline void move_start_to_next_entry(struct logdev_dev *ldev) +{ + struct logdev_dev_priv *dev = ldev->priv; + struct logdev_entry *entry = &dev->entry[dev->start]; + int start = dev->start; + int size; + struct logdev_header hdr; + + if (unlikely(dev->corrupted)) + goto corrupted; + + while (start == dev->start) { + logdev_copy_from_dev(ldev,(char*)&hdr,sizeof(hdr)); + entry = &dev->entry[dev->start]; + + if (!logdev_valid(hdr.id)) { + dev->corrupted = 1; + if (start == dev->start) + goto corrupted; + return; + } + + size = sizeof(hdr); + while (size < hdr.size) { + int count = hdr.size - size; + if (count > LOGDEV_ENTRY_SIZE(entry)) + count = LOGDEV_ENTRY_SIZE(entry); + dev->size -= count; + size += count; + LOGDEV_ENTRY_ADD(entry->head,count); + if (LOGDEV_ENTRY_SIZE(entry) == 0) { + dev->start = (dev->start + 1) % dev->len; + entry->head = entry->tail = 0; + entry = &dev->entry[dev->start]; + } + } + } + return; + + corrupted: + /* Don't trust headers, just skip to the next entry */ + dev->size -= LOGDEV_ENTRY_SIZE(entry); + entry->head = entry->tail = 0; + dev->start = (dev->start+1) % dev->len; + return; +} + +static inline int logdev_copy_to_dev(struct logdev_dev *ldev, const void *dat, + int size) +{ + struct logdev_dev_priv *dev = ldev->priv; + struct logdev_entry *entry = &dev->entry[dev->end]; + const char *buf = dat; + int ret = 0; + + while (size) { + int copy; + int free; + if (LOGDEV_ENTRY_SIZE(entry) == LOGDEV_ENTRY_MAX) { + dev->end = (dev->end+1) % dev->len; + entry = &dev->entry[dev->end]; + /* if we wrapped, then clear out this entire + * buffer. + */ + if (dev->end == dev->start) { + move_start_to_next_entry(ldev); + } + } + copy = size; + if (copy > (free=LOGDEV_ENTRY_FREE(entry))) + copy = free; + if (entry->tail+copy > PAGE_SIZE) + copy = PAGE_SIZE - entry->tail; + memcpy(entry->dat+entry->tail,buf,copy); + LOGDEV_ENTRY_ADD(entry->tail,copy); + buf += copy; + size -= copy; + ret += copy; + dev->size += copy; + + } + + return ret; + +} + +#endif /* __LINUX_LOGDEV_RINGBUF_H */