CPU might render the kernel unbootable.
If unsure, say N.
-
-config X86_DS
- def_bool X86_PTRACE_BTS
- depends on X86_DEBUGCTLMSR
- select HAVE_HW_BRANCH_TRACER
-
-config X86_PTRACE_BTS
- bool "Branch Trace Store"
- default y
- depends on X86_DEBUGCTLMSR
- depends on BROKEN
- ---help---
- This adds a ptrace interface to the hardware's branch trace store.
-
- Debuggers may use it to collect an execution trace of the debugged
- application in order to answer the question 'how did I get here?'.
- Debuggers may trace user mode as well as kernel mode.
-
- Say Y unless there is no application development on this machine
- and you want to save a small amount of code size.
Add a simple leak tracer to the IOMMU code. This is useful when you
are debugging a buggy device driver that leaks IOMMU mappings.
-config X86_DS_SELFTEST
- bool "DS selftest"
- default y
- depends on DEBUG_KERNEL
- depends on X86_DS
- ---help---
- Perform Debug Store selftests at boot time.
- If in doubt, say "N".
-
config HAVE_MMIOTRACE_SUPPORT
def_bool y
+++ /dev/null
-/*
- * Debug Store (DS) support
- *
- * This provides a low-level interface to the hardware's Debug Store
- * feature that is used for branch trace store (BTS) and
- * precise-event based sampling (PEBS).
- *
- * It manages:
- * - DS and BTS hardware configuration
- * - buffer overflow handling (to be done)
- * - buffer access
- *
- * It does not do:
- * - security checking (is the caller allowed to trace the task)
- * - buffer allocation (memory accounting)
- *
- *
- * Copyright (C) 2007-2009 Intel Corporation.
- * Markus Metzger <markus.t.metzger@intel.com>, 2007-2009
- */
-
-#ifndef _ASM_X86_DS_H
-#define _ASM_X86_DS_H
-
-
-#include <linux/types.h>
-#include <linux/init.h>
-#include <linux/err.h>
-
-
-#ifdef CONFIG_X86_DS
-
-struct task_struct;
-struct ds_context;
-struct ds_tracer;
-struct bts_tracer;
-struct pebs_tracer;
-
-typedef void (*bts_ovfl_callback_t)(struct bts_tracer *);
-typedef void (*pebs_ovfl_callback_t)(struct pebs_tracer *);
-
-
-/*
- * A list of features plus corresponding macros to talk about them in
- * the ds_request function's flags parameter.
- *
- * We use the enum to index an array of corresponding control bits;
- * we use the macro to index a flags bit-vector.
- */
-enum ds_feature {
- dsf_bts = 0,
- dsf_bts_kernel,
-#define BTS_KERNEL (1 << dsf_bts_kernel)
- /* trace kernel-mode branches */
-
- dsf_bts_user,
-#define BTS_USER (1 << dsf_bts_user)
- /* trace user-mode branches */
-
- dsf_bts_overflow,
- dsf_bts_max,
- dsf_pebs = dsf_bts_max,
-
- dsf_pebs_max,
- dsf_ctl_max = dsf_pebs_max,
- dsf_bts_timestamps = dsf_ctl_max,
-#define BTS_TIMESTAMPS (1 << dsf_bts_timestamps)
- /* add timestamps into BTS trace */
-
-#define BTS_USER_FLAGS (BTS_KERNEL | BTS_USER | BTS_TIMESTAMPS)
-};
-
-
-/*
- * Request BTS or PEBS
- *
- * Due to alignement constraints, the actual buffer may be slightly
- * smaller than the requested or provided buffer.
- *
- * Returns a pointer to a tracer structure on success, or
- * ERR_PTR(errcode) on failure.
- *
- * The interrupt threshold is independent from the overflow callback
- * to allow users to use their own overflow interrupt handling mechanism.
- *
- * The function might sleep.
- *
- * task: the task to request recording for
- * cpu: the cpu to request recording for
- * base: the base pointer for the (non-pageable) buffer;
- * size: the size of the provided buffer in bytes
- * ovfl: pointer to a function to be called on buffer overflow;
- * NULL if cyclic buffer requested
- * th: the interrupt threshold in records from the end of the buffer;
- * -1 if no interrupt threshold is requested.
- * flags: a bit-mask of the above flags
- */
-extern struct bts_tracer *ds_request_bts_task(struct task_struct *task,
- void *base, size_t size,
- bts_ovfl_callback_t ovfl,
- size_t th, unsigned int flags);
-extern struct bts_tracer *ds_request_bts_cpu(int cpu, void *base, size_t size,
- bts_ovfl_callback_t ovfl,
- size_t th, unsigned int flags);
-extern struct pebs_tracer *ds_request_pebs_task(struct task_struct *task,
- void *base, size_t size,
- pebs_ovfl_callback_t ovfl,
- size_t th, unsigned int flags);
-extern struct pebs_tracer *ds_request_pebs_cpu(int cpu,
- void *base, size_t size,
- pebs_ovfl_callback_t ovfl,
- size_t th, unsigned int flags);
-
-/*
- * Release BTS or PEBS resources
- * Suspend and resume BTS or PEBS tracing
- *
- * Must be called with irq's enabled.
- *
- * tracer: the tracer handle returned from ds_request_~()
- */
-extern void ds_release_bts(struct bts_tracer *tracer);
-extern void ds_suspend_bts(struct bts_tracer *tracer);
-extern void ds_resume_bts(struct bts_tracer *tracer);
-extern void ds_release_pebs(struct pebs_tracer *tracer);
-extern void ds_suspend_pebs(struct pebs_tracer *tracer);
-extern void ds_resume_pebs(struct pebs_tracer *tracer);
-
-/*
- * Release BTS or PEBS resources
- * Suspend and resume BTS or PEBS tracing
- *
- * Cpu tracers must call this on the traced cpu.
- * Task tracers must call ds_release_~_noirq() for themselves.
- *
- * May be called with irq's disabled.
- *
- * Returns 0 if successful;
- * -EPERM if the cpu tracer does not trace the current cpu.
- * -EPERM if the task tracer does not trace itself.
- *
- * tracer: the tracer handle returned from ds_request_~()
- */
-extern int ds_release_bts_noirq(struct bts_tracer *tracer);
-extern int ds_suspend_bts_noirq(struct bts_tracer *tracer);
-extern int ds_resume_bts_noirq(struct bts_tracer *tracer);
-extern int ds_release_pebs_noirq(struct pebs_tracer *tracer);
-extern int ds_suspend_pebs_noirq(struct pebs_tracer *tracer);
-extern int ds_resume_pebs_noirq(struct pebs_tracer *tracer);
-
-
-/*
- * The raw DS buffer state as it is used for BTS and PEBS recording.
- *
- * This is the low-level, arch-dependent interface for working
- * directly on the raw trace data.
- */
-struct ds_trace {
- /* the number of bts/pebs records */
- size_t n;
- /* the size of a bts/pebs record in bytes */
- size_t size;
- /* pointers into the raw buffer:
- - to the first entry */
- void *begin;
- /* - one beyond the last entry */
- void *end;
- /* - one beyond the newest entry */
- void *top;
- /* - the interrupt threshold */
- void *ith;
- /* flags given on ds_request() */
- unsigned int flags;
-};
-
-/*
- * An arch-independent view on branch trace data.
- */
-enum bts_qualifier {
- bts_invalid,
-#define BTS_INVALID bts_invalid
-
- bts_branch,
-#define BTS_BRANCH bts_branch
-
- bts_task_arrives,
-#define BTS_TASK_ARRIVES bts_task_arrives
-
- bts_task_departs,
-#define BTS_TASK_DEPARTS bts_task_departs
-
- bts_qual_bit_size = 4,
- bts_qual_max = (1 << bts_qual_bit_size),
-};
-
-struct bts_struct {
- __u64 qualifier;
- union {
- /* BTS_BRANCH */
- struct {
- __u64 from;
- __u64 to;
- } lbr;
- /* BTS_TASK_ARRIVES or BTS_TASK_DEPARTS */
- struct {
- __u64 clock;
- pid_t pid;
- } event;
- } variant;
-};
-
-
-/*
- * The BTS state.
- *
- * This gives access to the raw DS state and adds functions to provide
- * an arch-independent view of the BTS data.
- */
-struct bts_trace {
- struct ds_trace ds;
-
- int (*read)(struct bts_tracer *tracer, const void *at,
- struct bts_struct *out);
- int (*write)(struct bts_tracer *tracer, const struct bts_struct *in);
-};
-
-
-/*
- * The PEBS state.
- *
- * This gives access to the raw DS state and the PEBS-specific counter
- * reset value.
- */
-struct pebs_trace {
- struct ds_trace ds;
-
- /* the number of valid counters in the below array */
- unsigned int counters;
-
-#define MAX_PEBS_COUNTERS 4
- /* the counter reset value */
- unsigned long long counter_reset[MAX_PEBS_COUNTERS];
-};
-
-
-/*
- * Read the BTS or PEBS trace.
- *
- * Returns a view on the trace collected for the parameter tracer.
- *
- * The view remains valid as long as the traced task is not running or
- * the tracer is suspended.
- * Writes into the trace buffer are not reflected.
- *
- * tracer: the tracer handle returned from ds_request_~()
- */
-extern const struct bts_trace *ds_read_bts(struct bts_tracer *tracer);
-extern const struct pebs_trace *ds_read_pebs(struct pebs_tracer *tracer);
-
-
-/*
- * Reset the write pointer of the BTS/PEBS buffer.
- *
- * Returns 0 on success; -Eerrno on error
- *
- * tracer: the tracer handle returned from ds_request_~()
- */
-extern int ds_reset_bts(struct bts_tracer *tracer);
-extern int ds_reset_pebs(struct pebs_tracer *tracer);
-
-/*
- * Set the PEBS counter reset value.
- *
- * Returns 0 on success; -Eerrno on error
- *
- * tracer: the tracer handle returned from ds_request_pebs()
- * counter: the index of the counter
- * value: the new counter reset value
- */
-extern int ds_set_pebs_reset(struct pebs_tracer *tracer,
- unsigned int counter, u64 value);
-
-/*
- * Initialization
- */
-struct cpuinfo_x86;
-extern void __cpuinit ds_init_intel(struct cpuinfo_x86 *);
-
-/*
- * Context switch work
- */
-extern void ds_switch_to(struct task_struct *prev, struct task_struct *next);
-
-#else /* CONFIG_X86_DS */
-
-struct cpuinfo_x86;
-static inline void __cpuinit ds_init_intel(struct cpuinfo_x86 *ignored) {}
-static inline void ds_switch_to(struct task_struct *prev,
- struct task_struct *next) {}
-
-#endif /* CONFIG_X86_DS */
-#endif /* _ASM_X86_DS_H */
#include <asm/msr.h>
#include <asm/desc_defs.h>
#include <asm/nops.h>
-#include <asm/ds.h>
#include <linux/personality.h>
#include <linux/cpumask.h>
#include <linux/threads.h>
#include <linux/math64.h>
#include <linux/init.h>
+#include <linux/err.h>
#define HBP_NUM 4
/*
unsigned long iopl;
/* Max allowed port in the bitmap, in bytes: */
unsigned io_bitmap_max;
-/* MSR_IA32_DEBUGCTLMSR value to switch in if TIF_DEBUGCTLMSR is set. */
- unsigned long debugctlmsr;
- /* Debug Store context; see asm/ds.h */
- struct ds_context *ds_ctx;
};
static inline unsigned long native_get_debugreg(int regno)
return debugctlmsr;
}
-static inline unsigned long get_debugctlmsr_on_cpu(int cpu)
-{
- u64 debugctlmsr = 0;
- u32 val1, val2;
-
-#ifndef CONFIG_X86_DEBUGCTLMSR
- if (boot_cpu_data.x86 < 6)
- return 0;
-#endif
- rdmsr_on_cpu(cpu, MSR_IA32_DEBUGCTLMSR, &val1, &val2);
- debugctlmsr = val1 | ((u64)val2 << 32);
-
- return debugctlmsr;
-}
-
static inline void update_debugctlmsr(unsigned long debugctlmsr)
{
#ifndef CONFIG_X86_DEBUGCTLMSR
wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctlmsr);
}
-static inline void update_debugctlmsr_on_cpu(int cpu,
- unsigned long debugctlmsr)
-{
-#ifndef CONFIG_X86_DEBUGCTLMSR
- if (boot_cpu_data.x86 < 6)
- return;
-#endif
- wrmsr_on_cpu(cpu, MSR_IA32_DEBUGCTLMSR,
- (u32)((u64)debugctlmsr),
- (u32)((u64)debugctlmsr >> 32));
-}
-
/*
* from system description table in BIOS. Mostly for MCA use, but
* others may find it useful:
#ifndef __ASSEMBLY__
#include <linux/types.h>
-
-/* configuration/status structure used in PTRACE_BTS_CONFIG and
- PTRACE_BTS_STATUS commands.
-*/
-struct ptrace_bts_config {
- /* requested or actual size of BTS buffer in bytes */
- __u32 size;
- /* bitmask of below flags */
- __u32 flags;
- /* buffer overflow signal */
- __u32 signal;
- /* actual size of bts_struct in bytes */
- __u32 bts_size;
-};
-#endif /* __ASSEMBLY__ */
-
-#define PTRACE_BTS_O_TRACE 0x1 /* branch trace */
-#define PTRACE_BTS_O_SCHED 0x2 /* scheduling events w/ jiffies */
-#define PTRACE_BTS_O_SIGNAL 0x4 /* send SIG<signal> on buffer overflow
- instead of wrapping around */
-#define PTRACE_BTS_O_ALLOC 0x8 /* (re)allocate buffer */
-
-#define PTRACE_BTS_CONFIG 40
-/* Configure branch trace recording.
- ADDR points to a struct ptrace_bts_config.
- DATA gives the size of that buffer.
- A new buffer is allocated, if requested in the flags.
- An overflow signal may only be requested for new buffers.
- Returns the number of bytes read.
-*/
-#define PTRACE_BTS_STATUS 41
-/* Return the current configuration in a struct ptrace_bts_config
- pointed to by ADDR; DATA gives the size of that buffer.
- Returns the number of bytes written.
-*/
-#define PTRACE_BTS_SIZE 42
-/* Return the number of available BTS records for draining.
- DATA and ADDR are ignored.
-*/
-#define PTRACE_BTS_GET 43
-/* Get a single BTS record.
- DATA defines the index into the BTS array, where 0 is the newest
- entry, and higher indices refer to older entries.
- ADDR is pointing to struct bts_struct (see asm/ds.h).
-*/
-#define PTRACE_BTS_CLEAR 44
-/* Clear the BTS buffer.
- DATA and ADDR are ignored.
-*/
-#define PTRACE_BTS_DRAIN 45
-/* Read all available BTS records and clear the buffer.
- ADDR points to an array of struct bts_struct.
- DATA gives the size of that buffer.
- BTS records are read from oldest to newest.
- Returns number of BTS records drained.
-*/
+#endif
#endif /* _ASM_X86_PTRACE_ABI_H */
extern int do_set_thread_area(struct task_struct *p, int idx,
struct user_desc __user *info, int can_allocate);
-#ifdef CONFIG_X86_PTRACE_BTS
-extern void ptrace_bts_untrace(struct task_struct *tsk);
-
-#define arch_ptrace_untrace(tsk) ptrace_bts_untrace(tsk)
-#endif /* CONFIG_X86_PTRACE_BTS */
-
#endif /* __KERNEL__ */
#endif /* !__ASSEMBLY__ */
#define TIF_IO_BITMAP 22 /* uses I/O bitmap */
#define TIF_FREEZE 23 /* is freezing for suspend */
#define TIF_FORCED_TF 24 /* true if TF in eflags artificially */
-#define TIF_DEBUGCTLMSR 25 /* uses thread_struct.debugctlmsr */
-#define TIF_DS_AREA_MSR 26 /* uses thread_struct.ds_area_msr */
#define TIF_LAZY_MMU_UPDATES 27 /* task is updating the mmu lazily */
#define TIF_SYSCALL_TRACEPOINT 28 /* syscall tracepoint instrumentation */
#define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP)
#define _TIF_FREEZE (1 << TIF_FREEZE)
#define _TIF_FORCED_TF (1 << TIF_FORCED_TF)
-#define _TIF_DEBUGCTLMSR (1 << TIF_DEBUGCTLMSR)
-#define _TIF_DS_AREA_MSR (1 << TIF_DS_AREA_MSR)
#define _TIF_LAZY_MMU_UPDATES (1 << TIF_LAZY_MMU_UPDATES)
#define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
/* flags to check in __switch_to() */
#define _TIF_WORK_CTXSW \
- (_TIF_IO_BITMAP|_TIF_DEBUGCTLMSR|_TIF_DS_AREA_MSR|_TIF_NOTSC)
+ (_TIF_IO_BITMAP|_TIF_NOTSC)
#define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY)
#define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW|_TIF_DEBUG)
obj-y += process.o
obj-y += i387.o xsave.o
obj-y += ptrace.o
-obj-$(CONFIG_X86_DS) += ds.o
-obj-$(CONFIG_X86_DS_SELFTEST) += ds_selftest.o
obj-$(CONFIG_X86_32) += tls.o
obj-$(CONFIG_IA32_EMULATION) += tls.o
obj-y += step.o
#include <asm/processor.h>
#include <asm/pgtable.h>
#include <asm/msr.h>
-#include <asm/ds.h>
#include <asm/bugs.h>
#include <asm/cpu.h>
set_cpu_cap(c, X86_FEATURE_BTS);
if (!(l1 & (1<<12)))
set_cpu_cap(c, X86_FEATURE_PEBS);
- ds_init_intel(c);
}
if (c->x86 == 6 && c->x86_model == 29 && cpu_has_clflush)
+++ /dev/null
-/*
- * Debug Store support
- *
- * This provides a low-level interface to the hardware's Debug Store
- * feature that is used for branch trace store (BTS) and
- * precise-event based sampling (PEBS).
- *
- * It manages:
- * - DS and BTS hardware configuration
- * - buffer overflow handling (to be done)
- * - buffer access
- *
- * It does not do:
- * - security checking (is the caller allowed to trace the task)
- * - buffer allocation (memory accounting)
- *
- *
- * Copyright (C) 2007-2009 Intel Corporation.
- * Markus Metzger <markus.t.metzger@intel.com>, 2007-2009
- */
-
-#include <linux/kernel.h>
-#include <linux/string.h>
-#include <linux/errno.h>
-#include <linux/sched.h>
-#include <linux/slab.h>
-#include <linux/mm.h>
-#include <linux/trace_clock.h>
-
-#include <asm/ds.h>
-
-#include "ds_selftest.h"
-
-/*
- * The configuration for a particular DS hardware implementation:
- */
-struct ds_configuration {
- /* The name of the configuration: */
- const char *name;
-
- /* The size of pointer-typed fields in DS, BTS, and PEBS: */
- unsigned char sizeof_ptr_field;
-
- /* The size of a BTS/PEBS record in bytes: */
- unsigned char sizeof_rec[2];
-
- /* The number of pebs counter reset values in the DS structure. */
- unsigned char nr_counter_reset;
-
- /* Control bit-masks indexed by enum ds_feature: */
- unsigned long ctl[dsf_ctl_max];
-};
-static struct ds_configuration ds_cfg __read_mostly;
-
-
-/* Maximal size of a DS configuration: */
-#define MAX_SIZEOF_DS 0x80
-
-/* Maximal size of a BTS record: */
-#define MAX_SIZEOF_BTS (3 * 8)
-
-/* BTS and PEBS buffer alignment: */
-#define DS_ALIGNMENT (1 << 3)
-
-/* Number of buffer pointers in DS: */
-#define NUM_DS_PTR_FIELDS 8
-
-/* Size of a pebs reset value in DS: */
-#define PEBS_RESET_FIELD_SIZE 8
-
-/* Mask of control bits in the DS MSR register: */
-#define BTS_CONTROL \
- ( ds_cfg.ctl[dsf_bts] | \
- ds_cfg.ctl[dsf_bts_kernel] | \
- ds_cfg.ctl[dsf_bts_user] | \
- ds_cfg.ctl[dsf_bts_overflow] )
-
-/*
- * A BTS or PEBS tracer.
- *
- * This holds the configuration of the tracer and serves as a handle
- * to identify tracers.
- */
-struct ds_tracer {
- /* The DS context (partially) owned by this tracer. */
- struct ds_context *context;
- /* The buffer provided on ds_request() and its size in bytes. */
- void *buffer;
- size_t size;
-};
-
-struct bts_tracer {
- /* The common DS part: */
- struct ds_tracer ds;
-
- /* The trace including the DS configuration: */
- struct bts_trace trace;
-
- /* Buffer overflow notification function: */
- bts_ovfl_callback_t ovfl;
-
- /* Active flags affecting trace collection. */
- unsigned int flags;
-};
-
-struct pebs_tracer {
- /* The common DS part: */
- struct ds_tracer ds;
-
- /* The trace including the DS configuration: */
- struct pebs_trace trace;
-
- /* Buffer overflow notification function: */
- pebs_ovfl_callback_t ovfl;
-};
-
-/*
- * Debug Store (DS) save area configuration (see Intel64 and IA32
- * Architectures Software Developer's Manual, section 18.5)
- *
- * The DS configuration consists of the following fields; different
- * architetures vary in the size of those fields.
- *
- * - double-word aligned base linear address of the BTS buffer
- * - write pointer into the BTS buffer
- * - end linear address of the BTS buffer (one byte beyond the end of
- * the buffer)
- * - interrupt pointer into BTS buffer
- * (interrupt occurs when write pointer passes interrupt pointer)
- * - double-word aligned base linear address of the PEBS buffer
- * - write pointer into the PEBS buffer
- * - end linear address of the PEBS buffer (one byte beyond the end of
- * the buffer)
- * - interrupt pointer into PEBS buffer
- * (interrupt occurs when write pointer passes interrupt pointer)
- * - value to which counter is reset following counter overflow
- *
- * Later architectures use 64bit pointers throughout, whereas earlier
- * architectures use 32bit pointers in 32bit mode.
- *
- *
- * We compute the base address for the first 8 fields based on:
- * - the field size stored in the DS configuration
- * - the relative field position
- * - an offset giving the start of the respective region
- *
- * This offset is further used to index various arrays holding
- * information for BTS and PEBS at the respective index.
- *
- * On later 32bit processors, we only access the lower 32bit of the
- * 64bit pointer fields. The upper halves will be zeroed out.
- */
-
-enum ds_field {
- ds_buffer_base = 0,
- ds_index,
- ds_absolute_maximum,
- ds_interrupt_threshold,
-};
-
-enum ds_qualifier {
- ds_bts = 0,
- ds_pebs
-};
-
-static inline unsigned long
-ds_get(const unsigned char *base, enum ds_qualifier qual, enum ds_field field)
-{
- base += (ds_cfg.sizeof_ptr_field * (field + (4 * qual)));
- return *(unsigned long *)base;
-}
-
-static inline void
-ds_set(unsigned char *base, enum ds_qualifier qual, enum ds_field field,
- unsigned long value)
-{
- base += (ds_cfg.sizeof_ptr_field * (field + (4 * qual)));
- (*(unsigned long *)base) = value;
-}
-
-
-/*
- * Locking is done only for allocating BTS or PEBS resources.
- */
-static DEFINE_SPINLOCK(ds_lock);
-
-/*
- * We either support (system-wide) per-cpu or per-thread allocation.
- * We distinguish the two based on the task_struct pointer, where a
- * NULL pointer indicates per-cpu allocation for the current cpu.
- *
- * Allocations are use-counted. As soon as resources are allocated,
- * further allocations must be of the same type (per-cpu or
- * per-thread). We model this by counting allocations (i.e. the number
- * of tracers of a certain type) for one type negatively:
- * =0 no tracers
- * >0 number of per-thread tracers
- * <0 number of per-cpu tracers
- *
- * Tracers essentially gives the number of ds contexts for a certain
- * type of allocation.
- */
-static atomic_t tracers = ATOMIC_INIT(0);
-
-static inline int get_tracer(struct task_struct *task)
-{
- int error;
-
- spin_lock_irq(&ds_lock);
-
- if (task) {
- error = -EPERM;
- if (atomic_read(&tracers) < 0)
- goto out;
- atomic_inc(&tracers);
- } else {
- error = -EPERM;
- if (atomic_read(&tracers) > 0)
- goto out;
- atomic_dec(&tracers);
- }
-
- error = 0;
-out:
- spin_unlock_irq(&ds_lock);
- return error;
-}
-
-static inline void put_tracer(struct task_struct *task)
-{
- if (task)
- atomic_dec(&tracers);
- else
- atomic_inc(&tracers);
-}
-
-/*
- * The DS context is either attached to a thread or to a cpu:
- * - in the former case, the thread_struct contains a pointer to the
- * attached context.
- * - in the latter case, we use a static array of per-cpu context
- * pointers.
- *
- * Contexts are use-counted. They are allocated on first access and
- * deallocated when the last user puts the context.
- */
-struct ds_context {
- /* The DS configuration; goes into MSR_IA32_DS_AREA: */
- unsigned char ds[MAX_SIZEOF_DS];
-
- /* The owner of the BTS and PEBS configuration, respectively: */
- struct bts_tracer *bts_master;
- struct pebs_tracer *pebs_master;
-
- /* Use count: */
- unsigned long count;
-
- /* Pointer to the context pointer field: */
- struct ds_context **this;
-
- /* The traced task; NULL for cpu tracing: */
- struct task_struct *task;
-
- /* The traced cpu; only valid if task is NULL: */
- int cpu;
-};
-
-static DEFINE_PER_CPU(struct ds_context *, cpu_ds_context);
-
-
-static struct ds_context *ds_get_context(struct task_struct *task, int cpu)
-{
- struct ds_context **p_context =
- (task ? &task->thread.ds_ctx : &per_cpu(cpu_ds_context, cpu));
- struct ds_context *context = NULL;
- struct ds_context *new_context = NULL;
-
- /* Chances are small that we already have a context. */
- new_context = kzalloc(sizeof(*new_context), GFP_KERNEL);
- if (!new_context)
- return NULL;
-
- spin_lock_irq(&ds_lock);
-
- context = *p_context;
- if (likely(!context)) {
- context = new_context;
-
- context->this = p_context;
- context->task = task;
- context->cpu = cpu;
- context->count = 0;
-
- *p_context = context;
- }
-
- context->count++;
-
- spin_unlock_irq(&ds_lock);
-
- if (context != new_context)
- kfree(new_context);
-
- return context;
-}
-
-static void ds_put_context(struct ds_context *context)
-{
- struct task_struct *task;
- unsigned long irq;
-
- if (!context)
- return;
-
- spin_lock_irqsave(&ds_lock, irq);
-
- if (--context->count) {
- spin_unlock_irqrestore(&ds_lock, irq);
- return;
- }
-
- *(context->this) = NULL;
-
- task = context->task;
-
- if (task)
- clear_tsk_thread_flag(task, TIF_DS_AREA_MSR);
-
- /*
- * We leave the (now dangling) pointer to the DS configuration in
- * the DS_AREA msr. This is as good or as bad as replacing it with
- * NULL - the hardware would crash if we enabled tracing.
- *
- * This saves us some problems with having to write an msr on a
- * different cpu while preventing others from doing the same for the
- * next context for that same cpu.
- */
-
- spin_unlock_irqrestore(&ds_lock, irq);
-
- /* The context might still be in use for context switching. */
- if (task && (task != current))
- wait_task_context_switch(task);
-
- kfree(context);
-}
-
-static void ds_install_ds_area(struct ds_context *context)
-{
- unsigned long ds;
-
- ds = (unsigned long)context->ds;
-
- /*
- * There is a race between the bts master and the pebs master.
- *
- * The thread/cpu access is synchronized via get/put_cpu() for
- * task tracing and via wrmsr_on_cpu for cpu tracing.
- *
- * If bts and pebs are collected for the same task or same cpu,
- * the same confiuration is written twice.
- */
- if (context->task) {
- get_cpu();
- if (context->task == current)
- wrmsrl(MSR_IA32_DS_AREA, ds);
- set_tsk_thread_flag(context->task, TIF_DS_AREA_MSR);
- put_cpu();
- } else
- wrmsr_on_cpu(context->cpu, MSR_IA32_DS_AREA,
- (u32)((u64)ds), (u32)((u64)ds >> 32));
-}
-
-/*
- * Call the tracer's callback on a buffer overflow.
- *
- * context: the ds context
- * qual: the buffer type
- */
-static void ds_overflow(struct ds_context *context, enum ds_qualifier qual)
-{
- switch (qual) {
- case ds_bts:
- if (context->bts_master &&
- context->bts_master->ovfl)
- context->bts_master->ovfl(context->bts_master);
- break;
- case ds_pebs:
- if (context->pebs_master &&
- context->pebs_master->ovfl)
- context->pebs_master->ovfl(context->pebs_master);
- break;
- }
-}
-
-
-/*
- * Write raw data into the BTS or PEBS buffer.
- *
- * The remainder of any partially written record is zeroed out.
- *
- * context: the DS context
- * qual: the buffer type
- * record: the data to write
- * size: the size of the data
- */
-static int ds_write(struct ds_context *context, enum ds_qualifier qual,
- const void *record, size_t size)
-{
- int bytes_written = 0;
-
- if (!record)
- return -EINVAL;
-
- while (size) {
- unsigned long base, index, end, write_end, int_th;
- unsigned long write_size, adj_write_size;
-
- /*
- * Write as much as possible without producing an
- * overflow interrupt.
- *
- * Interrupt_threshold must either be
- * - bigger than absolute_maximum or
- * - point to a record between buffer_base and absolute_maximum
- *
- * Index points to a valid record.
- */
- base = ds_get(context->ds, qual, ds_buffer_base);
- index = ds_get(context->ds, qual, ds_index);
- end = ds_get(context->ds, qual, ds_absolute_maximum);
- int_th = ds_get(context->ds, qual, ds_interrupt_threshold);
-
- write_end = min(end, int_th);
-
- /*
- * If we are already beyond the interrupt threshold,
- * we fill the entire buffer.
- */
- if (write_end <= index)
- write_end = end;
-
- if (write_end <= index)
- break;
-
- write_size = min((unsigned long) size, write_end - index);
- memcpy((void *)index, record, write_size);
-
- record = (const char *)record + write_size;
- size -= write_size;
- bytes_written += write_size;
-
- adj_write_size = write_size / ds_cfg.sizeof_rec[qual];
- adj_write_size *= ds_cfg.sizeof_rec[qual];
-
- /* Zero out trailing bytes. */
- memset((char *)index + write_size, 0,
- adj_write_size - write_size);
- index += adj_write_size;
-
- if (index >= end)
- index = base;
- ds_set(context->ds, qual, ds_index, index);
-
- if (index >= int_th)
- ds_overflow(context, qual);
- }
-
- return bytes_written;
-}
-
-
-/*
- * Branch Trace Store (BTS) uses the following format. Different
- * architectures vary in the size of those fields.
- * - source linear address
- * - destination linear address
- * - flags
- *
- * Later architectures use 64bit pointers throughout, whereas earlier
- * architectures use 32bit pointers in 32bit mode.
- *
- * We compute the base address for the fields based on:
- * - the field size stored in the DS configuration
- * - the relative field position
- *
- * In order to store additional information in the BTS buffer, we use
- * a special source address to indicate that the record requires
- * special interpretation.
- *
- * Netburst indicated via a bit in the flags field whether the branch
- * was predicted; this is ignored.
- *
- * We use two levels of abstraction:
- * - the raw data level defined here
- * - an arch-independent level defined in ds.h
- */
-
-enum bts_field {
- bts_from,
- bts_to,
- bts_flags,
-
- bts_qual = bts_from,
- bts_clock = bts_to,
- bts_pid = bts_flags,
-
- bts_qual_mask = (bts_qual_max - 1),
- bts_escape = ((unsigned long)-1 & ~bts_qual_mask)
-};
-
-static inline unsigned long bts_get(const char *base, unsigned long field)
-{
- base += (ds_cfg.sizeof_ptr_field * field);
- return *(unsigned long *)base;
-}
-
-static inline void bts_set(char *base, unsigned long field, unsigned long val)
-{
- base += (ds_cfg.sizeof_ptr_field * field);
- (*(unsigned long *)base) = val;
-}
-
-
-/*
- * The raw BTS data is architecture dependent.
- *
- * For higher-level users, we give an arch-independent view.
- * - ds.h defines struct bts_struct
- * - bts_read translates one raw bts record into a bts_struct
- * - bts_write translates one bts_struct into the raw format and
- * writes it into the top of the parameter tracer's buffer.
- *
- * return: bytes read/written on success; -Eerrno, otherwise
- */
-static int
-bts_read(struct bts_tracer *tracer, const void *at, struct bts_struct *out)
-{
- if (!tracer)
- return -EINVAL;
-
- if (at < tracer->trace.ds.begin)
- return -EINVAL;
-
- if (tracer->trace.ds.end < (at + tracer->trace.ds.size))
- return -EINVAL;
-
- memset(out, 0, sizeof(*out));
- if ((bts_get(at, bts_qual) & ~bts_qual_mask) == bts_escape) {
- out->qualifier = (bts_get(at, bts_qual) & bts_qual_mask);
- out->variant.event.clock = bts_get(at, bts_clock);
- out->variant.event.pid = bts_get(at, bts_pid);
- } else {
- out->qualifier = bts_branch;
- out->variant.lbr.from = bts_get(at, bts_from);
- out->variant.lbr.to = bts_get(at, bts_to);
-
- if (!out->variant.lbr.from && !out->variant.lbr.to)
- out->qualifier = bts_invalid;
- }
-
- return ds_cfg.sizeof_rec[ds_bts];
-}
-
-static int bts_write(struct bts_tracer *tracer, const struct bts_struct *in)
-{
- unsigned char raw[MAX_SIZEOF_BTS];
-
- if (!tracer)
- return -EINVAL;
-
- if (MAX_SIZEOF_BTS < ds_cfg.sizeof_rec[ds_bts])
- return -EOVERFLOW;
-
- switch (in->qualifier) {
- case bts_invalid:
- bts_set(raw, bts_from, 0);
- bts_set(raw, bts_to, 0);
- bts_set(raw, bts_flags, 0);
- break;
- case bts_branch:
- bts_set(raw, bts_from, in->variant.lbr.from);
- bts_set(raw, bts_to, in->variant.lbr.to);
- bts_set(raw, bts_flags, 0);
- break;
- case bts_task_arrives:
- case bts_task_departs:
- bts_set(raw, bts_qual, (bts_escape | in->qualifier));
- bts_set(raw, bts_clock, in->variant.event.clock);
- bts_set(raw, bts_pid, in->variant.event.pid);
- break;
- default:
- return -EINVAL;
- }
-
- return ds_write(tracer->ds.context, ds_bts, raw,
- ds_cfg.sizeof_rec[ds_bts]);
-}
-
-
-static void ds_write_config(struct ds_context *context,
- struct ds_trace *cfg, enum ds_qualifier qual)
-{
- unsigned char *ds = context->ds;
-
- ds_set(ds, qual, ds_buffer_base, (unsigned long)cfg->begin);
- ds_set(ds, qual, ds_index, (unsigned long)cfg->top);
- ds_set(ds, qual, ds_absolute_maximum, (unsigned long)cfg->end);
- ds_set(ds, qual, ds_interrupt_threshold, (unsigned long)cfg->ith);
-}
-
-static void ds_read_config(struct ds_context *context,
- struct ds_trace *cfg, enum ds_qualifier qual)
-{
- unsigned char *ds = context->ds;
-
- cfg->begin = (void *)ds_get(ds, qual, ds_buffer_base);
- cfg->top = (void *)ds_get(ds, qual, ds_index);
- cfg->end = (void *)ds_get(ds, qual, ds_absolute_maximum);
- cfg->ith = (void *)ds_get(ds, qual, ds_interrupt_threshold);
-}
-
-static void ds_init_ds_trace(struct ds_trace *trace, enum ds_qualifier qual,
- void *base, size_t size, size_t ith,
- unsigned int flags) {
- unsigned long buffer, adj;
-
- /*
- * Adjust the buffer address and size to meet alignment
- * constraints:
- * - buffer is double-word aligned
- * - size is multiple of record size
- *
- * We checked the size at the very beginning; we have enough
- * space to do the adjustment.
- */
- buffer = (unsigned long)base;
-
- adj = ALIGN(buffer, DS_ALIGNMENT) - buffer;
- buffer += adj;
- size -= adj;
-
- trace->n = size / ds_cfg.sizeof_rec[qual];
- trace->size = ds_cfg.sizeof_rec[qual];
-
- size = (trace->n * trace->size);
-
- trace->begin = (void *)buffer;
- trace->top = trace->begin;
- trace->end = (void *)(buffer + size);
- /*
- * The value for 'no threshold' is -1, which will set the
- * threshold outside of the buffer, just like we want it.
- */
- ith *= ds_cfg.sizeof_rec[qual];
- trace->ith = (void *)(buffer + size - ith);
-
- trace->flags = flags;
-}
-
-
-static int ds_request(struct ds_tracer *tracer, struct ds_trace *trace,
- enum ds_qualifier qual, struct task_struct *task,
- int cpu, void *base, size_t size, size_t th)
-{
- struct ds_context *context;
- int error;
- size_t req_size;
-
- error = -EOPNOTSUPP;
- if (!ds_cfg.sizeof_rec[qual])
- goto out;
-
- error = -EINVAL;
- if (!base)
- goto out;
-
- req_size = ds_cfg.sizeof_rec[qual];
- /* We might need space for alignment adjustments. */
- if (!IS_ALIGNED((unsigned long)base, DS_ALIGNMENT))
- req_size += DS_ALIGNMENT;
-
- error = -EINVAL;
- if (size < req_size)
- goto out;
-
- if (th != (size_t)-1) {
- th *= ds_cfg.sizeof_rec[qual];
-
- error = -EINVAL;
- if (size <= th)
- goto out;
- }
-
- tracer->buffer = base;
- tracer->size = size;
-
- error = -ENOMEM;
- context = ds_get_context(task, cpu);
- if (!context)
- goto out;
- tracer->context = context;
-
- /*
- * Defer any tracer-specific initialization work for the context until
- * context ownership has been clarified.
- */
-
- error = 0;
- out:
- return error;
-}
-
-static struct bts_tracer *ds_request_bts(struct task_struct *task, int cpu,
- void *base, size_t size,
- bts_ovfl_callback_t ovfl, size_t th,
- unsigned int flags)
-{
- struct bts_tracer *tracer;
- int error;
-
- /* Buffer overflow notification is not yet implemented. */
- error = -EOPNOTSUPP;
- if (ovfl)
- goto out;
-
- error = get_tracer(task);
- if (error < 0)
- goto out;
-
- error = -ENOMEM;
- tracer = kzalloc(sizeof(*tracer), GFP_KERNEL);
- if (!tracer)
- goto out_put_tracer;
- tracer->ovfl = ovfl;
-
- /* Do some more error checking and acquire a tracing context. */
- error = ds_request(&tracer->ds, &tracer->trace.ds,
- ds_bts, task, cpu, base, size, th);
- if (error < 0)
- goto out_tracer;
-
- /* Claim the bts part of the tracing context we acquired above. */
- spin_lock_irq(&ds_lock);
-
- error = -EPERM;
- if (tracer->ds.context->bts_master)
- goto out_unlock;
- tracer->ds.context->bts_master = tracer;
-
- spin_unlock_irq(&ds_lock);
-
- /*
- * Now that we own the bts part of the context, let's complete the
- * initialization for that part.
- */
- ds_init_ds_trace(&tracer->trace.ds, ds_bts, base, size, th, flags);
- ds_write_config(tracer->ds.context, &tracer->trace.ds, ds_bts);
- ds_install_ds_area(tracer->ds.context);
-
- tracer->trace.read = bts_read;
- tracer->trace.write = bts_write;
-
- /* Start tracing. */
- ds_resume_bts(tracer);
-
- return tracer;
-
- out_unlock:
- spin_unlock_irq(&ds_lock);
- ds_put_context(tracer->ds.context);
- out_tracer:
- kfree(tracer);
- out_put_tracer:
- put_tracer(task);
- out:
- return ERR_PTR(error);
-}
-
-struct bts_tracer *ds_request_bts_task(struct task_struct *task,
- void *base, size_t size,
- bts_ovfl_callback_t ovfl,
- size_t th, unsigned int flags)
-{
- return ds_request_bts(task, 0, base, size, ovfl, th, flags);
-}
-
-struct bts_tracer *ds_request_bts_cpu(int cpu, void *base, size_t size,
- bts_ovfl_callback_t ovfl,
- size_t th, unsigned int flags)
-{
- return ds_request_bts(NULL, cpu, base, size, ovfl, th, flags);
-}
-
-static struct pebs_tracer *ds_request_pebs(struct task_struct *task, int cpu,
- void *base, size_t size,
- pebs_ovfl_callback_t ovfl, size_t th,
- unsigned int flags)
-{
- struct pebs_tracer *tracer;
- int error;
-
- /* Buffer overflow notification is not yet implemented. */
- error = -EOPNOTSUPP;
- if (ovfl)
- goto out;
-
- error = get_tracer(task);
- if (error < 0)
- goto out;
-
- error = -ENOMEM;
- tracer = kzalloc(sizeof(*tracer), GFP_KERNEL);
- if (!tracer)
- goto out_put_tracer;
- tracer->ovfl = ovfl;
-
- /* Do some more error checking and acquire a tracing context. */
- error = ds_request(&tracer->ds, &tracer->trace.ds,
- ds_pebs, task, cpu, base, size, th);
- if (error < 0)
- goto out_tracer;
-
- /* Claim the pebs part of the tracing context we acquired above. */
- spin_lock_irq(&ds_lock);
-
- error = -EPERM;
- if (tracer->ds.context->pebs_master)
- goto out_unlock;
- tracer->ds.context->pebs_master = tracer;
-
- spin_unlock_irq(&ds_lock);
-
- /*
- * Now that we own the pebs part of the context, let's complete the
- * initialization for that part.
- */
- ds_init_ds_trace(&tracer->trace.ds, ds_pebs, base, size, th, flags);
- ds_write_config(tracer->ds.context, &tracer->trace.ds, ds_pebs);
- ds_install_ds_area(tracer->ds.context);
-
- /* Start tracing. */
- ds_resume_pebs(tracer);
-
- return tracer;
-
- out_unlock:
- spin_unlock_irq(&ds_lock);
- ds_put_context(tracer->ds.context);
- out_tracer:
- kfree(tracer);
- out_put_tracer:
- put_tracer(task);
- out:
- return ERR_PTR(error);
-}
-
-struct pebs_tracer *ds_request_pebs_task(struct task_struct *task,
- void *base, size_t size,
- pebs_ovfl_callback_t ovfl,
- size_t th, unsigned int flags)
-{
- return ds_request_pebs(task, 0, base, size, ovfl, th, flags);
-}
-
-struct pebs_tracer *ds_request_pebs_cpu(int cpu, void *base, size_t size,
- pebs_ovfl_callback_t ovfl,
- size_t th, unsigned int flags)
-{
- return ds_request_pebs(NULL, cpu, base, size, ovfl, th, flags);
-}
-
-static void ds_free_bts(struct bts_tracer *tracer)
-{
- struct task_struct *task;
-
- task = tracer->ds.context->task;
-
- WARN_ON_ONCE(tracer->ds.context->bts_master != tracer);
- tracer->ds.context->bts_master = NULL;
-
- /* Make sure tracing stopped and the tracer is not in use. */
- if (task && (task != current))
- wait_task_context_switch(task);
-
- ds_put_context(tracer->ds.context);
- put_tracer(task);
-
- kfree(tracer);
-}
-
-void ds_release_bts(struct bts_tracer *tracer)
-{
- might_sleep();
-
- if (!tracer)
- return;
-
- ds_suspend_bts(tracer);
- ds_free_bts(tracer);
-}
-
-int ds_release_bts_noirq(struct bts_tracer *tracer)
-{
- struct task_struct *task;
- unsigned long irq;
- int error;
-
- if (!tracer)
- return 0;
-
- task = tracer->ds.context->task;
-
- local_irq_save(irq);
-
- error = -EPERM;
- if (!task &&
- (tracer->ds.context->cpu != smp_processor_id()))
- goto out;
-
- error = -EPERM;
- if (task && (task != current))
- goto out;
-
- ds_suspend_bts_noirq(tracer);
- ds_free_bts(tracer);
-
- error = 0;
- out:
- local_irq_restore(irq);
- return error;
-}
-
-static void update_task_debugctlmsr(struct task_struct *task,
- unsigned long debugctlmsr)
-{
- task->thread.debugctlmsr = debugctlmsr;
-
- get_cpu();
- if (task == current)
- update_debugctlmsr(debugctlmsr);
- put_cpu();
-}
-
-void ds_suspend_bts(struct bts_tracer *tracer)
-{
- struct task_struct *task;
- unsigned long debugctlmsr;
- int cpu;
-
- if (!tracer)
- return;
-
- tracer->flags = 0;
-
- task = tracer->ds.context->task;
- cpu = tracer->ds.context->cpu;
-
- WARN_ON(!task && irqs_disabled());
-
- debugctlmsr = (task ?
- task->thread.debugctlmsr :
- get_debugctlmsr_on_cpu(cpu));
- debugctlmsr &= ~BTS_CONTROL;
-
- if (task)
- update_task_debugctlmsr(task, debugctlmsr);
- else
- update_debugctlmsr_on_cpu(cpu, debugctlmsr);
-}
-
-int ds_suspend_bts_noirq(struct bts_tracer *tracer)
-{
- struct task_struct *task;
- unsigned long debugctlmsr, irq;
- int cpu, error = 0;
-
- if (!tracer)
- return 0;
-
- tracer->flags = 0;
-
- task = tracer->ds.context->task;
- cpu = tracer->ds.context->cpu;
-
- local_irq_save(irq);
-
- error = -EPERM;
- if (!task && (cpu != smp_processor_id()))
- goto out;
-
- debugctlmsr = (task ?
- task->thread.debugctlmsr :
- get_debugctlmsr());
- debugctlmsr &= ~BTS_CONTROL;
-
- if (task)
- update_task_debugctlmsr(task, debugctlmsr);
- else
- update_debugctlmsr(debugctlmsr);
-
- error = 0;
- out:
- local_irq_restore(irq);
- return error;
-}
-
-static unsigned long ds_bts_control(struct bts_tracer *tracer)
-{
- unsigned long control;
-
- control = ds_cfg.ctl[dsf_bts];
- if (!(tracer->trace.ds.flags & BTS_KERNEL))
- control |= ds_cfg.ctl[dsf_bts_kernel];
- if (!(tracer->trace.ds.flags & BTS_USER))
- control |= ds_cfg.ctl[dsf_bts_user];
-
- return control;
-}
-
-void ds_resume_bts(struct bts_tracer *tracer)
-{
- struct task_struct *task;
- unsigned long debugctlmsr;
- int cpu;
-
- if (!tracer)
- return;
-
- tracer->flags = tracer->trace.ds.flags;
-
- task = tracer->ds.context->task;
- cpu = tracer->ds.context->cpu;
-
- WARN_ON(!task && irqs_disabled());
-
- debugctlmsr = (task ?
- task->thread.debugctlmsr :
- get_debugctlmsr_on_cpu(cpu));
- debugctlmsr |= ds_bts_control(tracer);
-
- if (task)
- update_task_debugctlmsr(task, debugctlmsr);
- else
- update_debugctlmsr_on_cpu(cpu, debugctlmsr);
-}
-
-int ds_resume_bts_noirq(struct bts_tracer *tracer)
-{
- struct task_struct *task;
- unsigned long debugctlmsr, irq;
- int cpu, error = 0;
-
- if (!tracer)
- return 0;
-
- tracer->flags = tracer->trace.ds.flags;
-
- task = tracer->ds.context->task;
- cpu = tracer->ds.context->cpu;
-
- local_irq_save(irq);
-
- error = -EPERM;
- if (!task && (cpu != smp_processor_id()))
- goto out;
-
- debugctlmsr = (task ?
- task->thread.debugctlmsr :
- get_debugctlmsr());
- debugctlmsr |= ds_bts_control(tracer);
-
- if (task)
- update_task_debugctlmsr(task, debugctlmsr);
- else
- update_debugctlmsr(debugctlmsr);
-
- error = 0;
- out:
- local_irq_restore(irq);
- return error;
-}
-
-static void ds_free_pebs(struct pebs_tracer *tracer)
-{
- struct task_struct *task;
-
- task = tracer->ds.context->task;
-
- WARN_ON_ONCE(tracer->ds.context->pebs_master != tracer);
- tracer->ds.context->pebs_master = NULL;
-
- ds_put_context(tracer->ds.context);
- put_tracer(task);
-
- kfree(tracer);
-}
-
-void ds_release_pebs(struct pebs_tracer *tracer)
-{
- might_sleep();
-
- if (!tracer)
- return;
-
- ds_suspend_pebs(tracer);
- ds_free_pebs(tracer);
-}
-
-int ds_release_pebs_noirq(struct pebs_tracer *tracer)
-{
- struct task_struct *task;
- unsigned long irq;
- int error;
-
- if (!tracer)
- return 0;
-
- task = tracer->ds.context->task;
-
- local_irq_save(irq);
-
- error = -EPERM;
- if (!task &&
- (tracer->ds.context->cpu != smp_processor_id()))
- goto out;
-
- error = -EPERM;
- if (task && (task != current))
- goto out;
-
- ds_suspend_pebs_noirq(tracer);
- ds_free_pebs(tracer);
-
- error = 0;
- out:
- local_irq_restore(irq);
- return error;
-}
-
-void ds_suspend_pebs(struct pebs_tracer *tracer)
-{
-
-}
-
-int ds_suspend_pebs_noirq(struct pebs_tracer *tracer)
-{
- return 0;
-}
-
-void ds_resume_pebs(struct pebs_tracer *tracer)
-{
-
-}
-
-int ds_resume_pebs_noirq(struct pebs_tracer *tracer)
-{
- return 0;
-}
-
-const struct bts_trace *ds_read_bts(struct bts_tracer *tracer)
-{
- if (!tracer)
- return NULL;
-
- ds_read_config(tracer->ds.context, &tracer->trace.ds, ds_bts);
- return &tracer->trace;
-}
-
-const struct pebs_trace *ds_read_pebs(struct pebs_tracer *tracer)
-{
- if (!tracer)
- return NULL;
-
- ds_read_config(tracer->ds.context, &tracer->trace.ds, ds_pebs);
-
- tracer->trace.counters = ds_cfg.nr_counter_reset;
- memcpy(tracer->trace.counter_reset,
- tracer->ds.context->ds +
- (NUM_DS_PTR_FIELDS * ds_cfg.sizeof_ptr_field),
- ds_cfg.nr_counter_reset * PEBS_RESET_FIELD_SIZE);
-
- return &tracer->trace;
-}
-
-int ds_reset_bts(struct bts_tracer *tracer)
-{
- if (!tracer)
- return -EINVAL;
-
- tracer->trace.ds.top = tracer->trace.ds.begin;
-
- ds_set(tracer->ds.context->ds, ds_bts, ds_index,
- (unsigned long)tracer->trace.ds.top);
-
- return 0;
-}
-
-int ds_reset_pebs(struct pebs_tracer *tracer)
-{
- if (!tracer)
- return -EINVAL;
-
- tracer->trace.ds.top = tracer->trace.ds.begin;
-
- ds_set(tracer->ds.context->ds, ds_pebs, ds_index,
- (unsigned long)tracer->trace.ds.top);
-
- return 0;
-}
-
-int ds_set_pebs_reset(struct pebs_tracer *tracer,
- unsigned int counter, u64 value)
-{
- if (!tracer)
- return -EINVAL;
-
- if (ds_cfg.nr_counter_reset < counter)
- return -EINVAL;
-
- *(u64 *)(tracer->ds.context->ds +
- (NUM_DS_PTR_FIELDS * ds_cfg.sizeof_ptr_field) +
- (counter * PEBS_RESET_FIELD_SIZE)) = value;
-
- return 0;
-}
-
-static const struct ds_configuration ds_cfg_netburst = {
- .name = "Netburst",
- .ctl[dsf_bts] = (1 << 2) | (1 << 3),
- .ctl[dsf_bts_kernel] = (1 << 5),
- .ctl[dsf_bts_user] = (1 << 6),
- .nr_counter_reset = 1,
-};
-static const struct ds_configuration ds_cfg_pentium_m = {
- .name = "Pentium M",
- .ctl[dsf_bts] = (1 << 6) | (1 << 7),
- .nr_counter_reset = 1,
-};
-static const struct ds_configuration ds_cfg_core2_atom = {
- .name = "Core 2/Atom",
- .ctl[dsf_bts] = (1 << 6) | (1 << 7),
- .ctl[dsf_bts_kernel] = (1 << 9),
- .ctl[dsf_bts_user] = (1 << 10),
- .nr_counter_reset = 1,
-};
-static const struct ds_configuration ds_cfg_core_i7 = {
- .name = "Core i7",
- .ctl[dsf_bts] = (1 << 6) | (1 << 7),
- .ctl[dsf_bts_kernel] = (1 << 9),
- .ctl[dsf_bts_user] = (1 << 10),
- .nr_counter_reset = 4,
-};
-
-static void
-ds_configure(const struct ds_configuration *cfg,
- struct cpuinfo_x86 *cpu)
-{
- unsigned long nr_pebs_fields = 0;
-
- printk(KERN_INFO "[ds] using %s configuration\n", cfg->name);
-
-#ifdef __i386__
- nr_pebs_fields = 10;
-#else
- nr_pebs_fields = 18;
-#endif
-
- /*
- * Starting with version 2, architectural performance
- * monitoring supports a format specifier.
- */
- if ((cpuid_eax(0xa) & 0xff) > 1) {
- unsigned long perf_capabilities, format;
-
- rdmsrl(MSR_IA32_PERF_CAPABILITIES, perf_capabilities);
-
- format = (perf_capabilities >> 8) & 0xf;
-
- switch (format) {
- case 0:
- nr_pebs_fields = 18;
- break;
- case 1:
- nr_pebs_fields = 22;
- break;
- default:
- printk(KERN_INFO
- "[ds] unknown PEBS format: %lu\n", format);
- nr_pebs_fields = 0;
- break;
- }
- }
-
- memset(&ds_cfg, 0, sizeof(ds_cfg));
- ds_cfg = *cfg;
-
- ds_cfg.sizeof_ptr_field =
- (cpu_has(cpu, X86_FEATURE_DTES64) ? 8 : 4);
-
- ds_cfg.sizeof_rec[ds_bts] = ds_cfg.sizeof_ptr_field * 3;
- ds_cfg.sizeof_rec[ds_pebs] = ds_cfg.sizeof_ptr_field * nr_pebs_fields;
-
- if (!cpu_has(cpu, X86_FEATURE_BTS)) {
- ds_cfg.sizeof_rec[ds_bts] = 0;
- printk(KERN_INFO "[ds] bts not available\n");
- }
- if (!cpu_has(cpu, X86_FEATURE_PEBS)) {
- ds_cfg.sizeof_rec[ds_pebs] = 0;
- printk(KERN_INFO "[ds] pebs not available\n");
- }
-
- printk(KERN_INFO "[ds] sizes: address: %u bit, ",
- 8 * ds_cfg.sizeof_ptr_field);
- printk("bts/pebs record: %u/%u bytes\n",
- ds_cfg.sizeof_rec[ds_bts], ds_cfg.sizeof_rec[ds_pebs]);
-
- WARN_ON_ONCE(MAX_PEBS_COUNTERS < ds_cfg.nr_counter_reset);
-}
-
-void __cpuinit ds_init_intel(struct cpuinfo_x86 *c)
-{
- /* Only configure the first cpu. Others are identical. */
- if (ds_cfg.name)
- return;
-
- switch (c->x86) {
- case 0x6:
- switch (c->x86_model) {
- case 0x9:
- case 0xd: /* Pentium M */
- ds_configure(&ds_cfg_pentium_m, c);
- break;
- case 0xf:
- case 0x17: /* Core2 */
- case 0x1c: /* Atom */
- ds_configure(&ds_cfg_core2_atom, c);
- break;
- case 0x1a: /* Core i7 */
- ds_configure(&ds_cfg_core_i7, c);
- break;
- default:
- /* Sorry, don't know about them. */
- break;
- }
- break;
- case 0xf:
- switch (c->x86_model) {
- case 0x0:
- case 0x1:
- case 0x2: /* Netburst */
- ds_configure(&ds_cfg_netburst, c);
- break;
- default:
- /* Sorry, don't know about them. */
- break;
- }
- break;
- default:
- /* Sorry, don't know about them. */
- break;
- }
-}
-
-static inline void ds_take_timestamp(struct ds_context *context,
- enum bts_qualifier qualifier,
- struct task_struct *task)
-{
- struct bts_tracer *tracer = context->bts_master;
- struct bts_struct ts;
-
- /* Prevent compilers from reading the tracer pointer twice. */
- barrier();
-
- if (!tracer || !(tracer->flags & BTS_TIMESTAMPS))
- return;
-
- memset(&ts, 0, sizeof(ts));
- ts.qualifier = qualifier;
- ts.variant.event.clock = trace_clock_global();
- ts.variant.event.pid = task->pid;
-
- bts_write(tracer, &ts);
-}
-
-/*
- * Change the DS configuration from tracing prev to tracing next.
- */
-void ds_switch_to(struct task_struct *prev, struct task_struct *next)
-{
- struct ds_context *prev_ctx = prev->thread.ds_ctx;
- struct ds_context *next_ctx = next->thread.ds_ctx;
- unsigned long debugctlmsr = next->thread.debugctlmsr;
-
- /* Make sure all data is read before we start. */
- barrier();
-
- if (prev_ctx) {
- update_debugctlmsr(0);
-
- ds_take_timestamp(prev_ctx, bts_task_departs, prev);
- }
-
- if (next_ctx) {
- ds_take_timestamp(next_ctx, bts_task_arrives, next);
-
- wrmsrl(MSR_IA32_DS_AREA, (unsigned long)next_ctx->ds);
- }
-
- update_debugctlmsr(debugctlmsr);
-}
-
-static __init int ds_selftest(void)
-{
- if (ds_cfg.sizeof_rec[ds_bts]) {
- int error;
-
- error = ds_selftest_bts();
- if (error) {
- WARN(1, "[ds] selftest failed. disabling bts.\n");
- ds_cfg.sizeof_rec[ds_bts] = 0;
- }
- }
-
- if (ds_cfg.sizeof_rec[ds_pebs]) {
- int error;
-
- error = ds_selftest_pebs();
- if (error) {
- WARN(1, "[ds] selftest failed. disabling pebs.\n");
- ds_cfg.sizeof_rec[ds_pebs] = 0;
- }
- }
-
- return 0;
-}
-device_initcall(ds_selftest);
+++ /dev/null
-/*
- * Debug Store support - selftest
- *
- *
- * Copyright (C) 2009 Intel Corporation.
- * Markus Metzger <markus.t.metzger@intel.com>, 2009
- */
-
-#include "ds_selftest.h"
-
-#include <linux/kernel.h>
-#include <linux/string.h>
-#include <linux/smp.h>
-#include <linux/cpu.h>
-
-#include <asm/ds.h>
-
-
-#define BUFFER_SIZE 521 /* Intentionally chose an odd size. */
-#define SMALL_BUFFER_SIZE 24 /* A single bts entry. */
-
-struct ds_selftest_bts_conf {
- struct bts_tracer *tracer;
- int error;
- int (*suspend)(struct bts_tracer *);
- int (*resume)(struct bts_tracer *);
-};
-
-static int ds_selftest_bts_consistency(const struct bts_trace *trace)
-{
- int error = 0;
-
- if (!trace) {
- printk(KERN_CONT "failed to access trace...");
- /* Bail out. Other tests are pointless. */
- return -1;
- }
-
- if (!trace->read) {
- printk(KERN_CONT "bts read not available...");
- error = -1;
- }
-
- /* Do some sanity checks on the trace configuration. */
- if (!trace->ds.n) {
- printk(KERN_CONT "empty bts buffer...");
- error = -1;
- }
- if (!trace->ds.size) {
- printk(KERN_CONT "bad bts trace setup...");
- error = -1;
- }
- if (trace->ds.end !=
- (char *)trace->ds.begin + (trace->ds.n * trace->ds.size)) {
- printk(KERN_CONT "bad bts buffer setup...");
- error = -1;
- }
- /*
- * We allow top in [begin; end], since its not clear when the
- * overflow adjustment happens: after the increment or before the
- * write.
- */
- if ((trace->ds.top < trace->ds.begin) ||
- (trace->ds.end < trace->ds.top)) {
- printk(KERN_CONT "bts top out of bounds...");
- error = -1;
- }
-
- return error;
-}
-
-static int ds_selftest_bts_read(struct bts_tracer *tracer,
- const struct bts_trace *trace,
- const void *from, const void *to)
-{
- const unsigned char *at;
-
- /*
- * Check a few things which do not belong to this test.
- * They should be covered by other tests.
- */
- if (!trace)
- return -1;
-
- if (!trace->read)
- return -1;
-
- if (to < from)
- return -1;
-
- if (from < trace->ds.begin)
- return -1;
-
- if (trace->ds.end < to)
- return -1;
-
- if (!trace->ds.size)
- return -1;
-
- /* Now to the test itself. */
- for (at = from; (void *)at < to; at += trace->ds.size) {
- struct bts_struct bts;
- unsigned long index;
- int error;
-
- if (((void *)at - trace->ds.begin) % trace->ds.size) {
- printk(KERN_CONT
- "read from non-integer index...");
- return -1;
- }
- index = ((void *)at - trace->ds.begin) / trace->ds.size;
-
- memset(&bts, 0, sizeof(bts));
- error = trace->read(tracer, at, &bts);
- if (error < 0) {
- printk(KERN_CONT
- "error reading bts trace at [%lu] (0x%p)...",
- index, at);
- return error;
- }
-
- switch (bts.qualifier) {
- case BTS_BRANCH:
- break;
- default:
- printk(KERN_CONT
- "unexpected bts entry %llu at [%lu] (0x%p)...",
- bts.qualifier, index, at);
- return -1;
- }
- }
-
- return 0;
-}
-
-static void ds_selftest_bts_cpu(void *arg)
-{
- struct ds_selftest_bts_conf *conf = arg;
- const struct bts_trace *trace;
- void *top;
-
- if (IS_ERR(conf->tracer)) {
- conf->error = PTR_ERR(conf->tracer);
- conf->tracer = NULL;
-
- printk(KERN_CONT
- "initialization failed (err: %d)...", conf->error);
- return;
- }
-
- /* We should meanwhile have enough trace. */
- conf->error = conf->suspend(conf->tracer);
- if (conf->error < 0)
- return;
-
- /* Let's see if we can access the trace. */
- trace = ds_read_bts(conf->tracer);
-
- conf->error = ds_selftest_bts_consistency(trace);
- if (conf->error < 0)
- return;
-
- /* If everything went well, we should have a few trace entries. */
- if (trace->ds.top == trace->ds.begin) {
- /*
- * It is possible but highly unlikely that we got a
- * buffer overflow and end up at exactly the same
- * position we started from.
- * Let's issue a warning, but continue.
- */
- printk(KERN_CONT "no trace/overflow...");
- }
-
- /* Let's try to read the trace we collected. */
- conf->error =
- ds_selftest_bts_read(conf->tracer, trace,
- trace->ds.begin, trace->ds.top);
- if (conf->error < 0)
- return;
-
- /*
- * Let's read the trace again.
- * Since we suspended tracing, we should get the same result.
- */
- top = trace->ds.top;
-
- trace = ds_read_bts(conf->tracer);
- conf->error = ds_selftest_bts_consistency(trace);
- if (conf->error < 0)
- return;
-
- if (top != trace->ds.top) {
- printk(KERN_CONT "suspend not working...");
- conf->error = -1;
- return;
- }
-
- /* Let's collect some more trace - see if resume is working. */
- conf->error = conf->resume(conf->tracer);
- if (conf->error < 0)
- return;
-
- conf->error = conf->suspend(conf->tracer);
- if (conf->error < 0)
- return;
-
- trace = ds_read_bts(conf->tracer);
-
- conf->error = ds_selftest_bts_consistency(trace);
- if (conf->error < 0)
- return;
-
- if (trace->ds.top == top) {
- /*
- * It is possible but highly unlikely that we got a
- * buffer overflow and end up at exactly the same
- * position we started from.
- * Let's issue a warning and check the full trace.
- */
- printk(KERN_CONT
- "no resume progress/overflow...");
-
- conf->error =
- ds_selftest_bts_read(conf->tracer, trace,
- trace->ds.begin, trace->ds.end);
- } else if (trace->ds.top < top) {
- /*
- * We had a buffer overflow - the entire buffer should
- * contain trace records.
- */
- conf->error =
- ds_selftest_bts_read(conf->tracer, trace,
- trace->ds.begin, trace->ds.end);
- } else {
- /*
- * It is quite likely that the buffer did not overflow.
- * Let's just check the delta trace.
- */
- conf->error =
- ds_selftest_bts_read(conf->tracer, trace, top,
- trace->ds.top);
- }
- if (conf->error < 0)
- return;
-
- conf->error = 0;
-}
-
-static int ds_suspend_bts_wrap(struct bts_tracer *tracer)
-{
- ds_suspend_bts(tracer);
- return 0;
-}
-
-static int ds_resume_bts_wrap(struct bts_tracer *tracer)
-{
- ds_resume_bts(tracer);
- return 0;
-}
-
-static void ds_release_bts_noirq_wrap(void *tracer)
-{
- (void)ds_release_bts_noirq(tracer);
-}
-
-static int ds_selftest_bts_bad_release_noirq(int cpu,
- struct bts_tracer *tracer)
-{
- int error = -EPERM;
-
- /* Try to release the tracer on the wrong cpu. */
- get_cpu();
- if (cpu != smp_processor_id()) {
- error = ds_release_bts_noirq(tracer);
- if (error != -EPERM)
- printk(KERN_CONT "release on wrong cpu...");
- }
- put_cpu();
-
- return error ? 0 : -1;
-}
-
-static int ds_selftest_bts_bad_request_cpu(int cpu, void *buffer)
-{
- struct bts_tracer *tracer;
- int error;
-
- /* Try to request cpu tracing while task tracing is active. */
- tracer = ds_request_bts_cpu(cpu, buffer, BUFFER_SIZE, NULL,
- (size_t)-1, BTS_KERNEL);
- error = PTR_ERR(tracer);
- if (!IS_ERR(tracer)) {
- ds_release_bts(tracer);
- error = 0;
- }
-
- if (error != -EPERM)
- printk(KERN_CONT "cpu/task tracing overlap...");
-
- return error ? 0 : -1;
-}
-
-static int ds_selftest_bts_bad_request_task(void *buffer)
-{
- struct bts_tracer *tracer;
- int error;
-
- /* Try to request cpu tracing while task tracing is active. */
- tracer = ds_request_bts_task(current, buffer, BUFFER_SIZE, NULL,
- (size_t)-1, BTS_KERNEL);
- error = PTR_ERR(tracer);
- if (!IS_ERR(tracer)) {
- error = 0;
- ds_release_bts(tracer);
- }
-
- if (error != -EPERM)
- printk(KERN_CONT "task/cpu tracing overlap...");
-
- return error ? 0 : -1;
-}
-
-int ds_selftest_bts(void)
-{
- struct ds_selftest_bts_conf conf;
- unsigned char buffer[BUFFER_SIZE], *small_buffer;
- unsigned long irq;
- int cpu;
-
- printk(KERN_INFO "[ds] bts selftest...");
- conf.error = 0;
-
- small_buffer = (unsigned char *)ALIGN((unsigned long)buffer, 8) + 8;
-
- get_online_cpus();
- for_each_online_cpu(cpu) {
- conf.suspend = ds_suspend_bts_wrap;
- conf.resume = ds_resume_bts_wrap;
- conf.tracer =
- ds_request_bts_cpu(cpu, buffer, BUFFER_SIZE,
- NULL, (size_t)-1, BTS_KERNEL);
- ds_selftest_bts_cpu(&conf);
- if (conf.error >= 0)
- conf.error = ds_selftest_bts_bad_request_task(buffer);
- ds_release_bts(conf.tracer);
- if (conf.error < 0)
- goto out;
-
- conf.suspend = ds_suspend_bts_noirq;
- conf.resume = ds_resume_bts_noirq;
- conf.tracer =
- ds_request_bts_cpu(cpu, buffer, BUFFER_SIZE,
- NULL, (size_t)-1, BTS_KERNEL);
- smp_call_function_single(cpu, ds_selftest_bts_cpu, &conf, 1);
- if (conf.error >= 0) {
- conf.error =
- ds_selftest_bts_bad_release_noirq(cpu,
- conf.tracer);
- /* We must not release the tracer twice. */
- if (conf.error < 0)
- conf.tracer = NULL;
- }
- if (conf.error >= 0)
- conf.error = ds_selftest_bts_bad_request_task(buffer);
- smp_call_function_single(cpu, ds_release_bts_noirq_wrap,
- conf.tracer, 1);
- if (conf.error < 0)
- goto out;
- }
-
- conf.suspend = ds_suspend_bts_wrap;
- conf.resume = ds_resume_bts_wrap;
- conf.tracer =
- ds_request_bts_task(current, buffer, BUFFER_SIZE,
- NULL, (size_t)-1, BTS_KERNEL);
- ds_selftest_bts_cpu(&conf);
- if (conf.error >= 0)
- conf.error = ds_selftest_bts_bad_request_cpu(0, buffer);
- ds_release_bts(conf.tracer);
- if (conf.error < 0)
- goto out;
-
- conf.suspend = ds_suspend_bts_noirq;
- conf.resume = ds_resume_bts_noirq;
- conf.tracer =
- ds_request_bts_task(current, small_buffer, SMALL_BUFFER_SIZE,
- NULL, (size_t)-1, BTS_KERNEL);
- local_irq_save(irq);
- ds_selftest_bts_cpu(&conf);
- if (conf.error >= 0)
- conf.error = ds_selftest_bts_bad_request_cpu(0, buffer);
- ds_release_bts_noirq(conf.tracer);
- local_irq_restore(irq);
- if (conf.error < 0)
- goto out;
-
- conf.error = 0;
- out:
- put_online_cpus();
- printk(KERN_CONT "%s.\n", (conf.error ? "failed" : "passed"));
-
- return conf.error;
-}
-
-int ds_selftest_pebs(void)
-{
- return 0;
-}
+++ /dev/null
-/*
- * Debug Store support - selftest
- *
- *
- * Copyright (C) 2009 Intel Corporation.
- * Markus Metzger <markus.t.metzger@intel.com>, 2009
- */
-
-#ifdef CONFIG_X86_DS_SELFTEST
-extern int ds_selftest_bts(void);
-extern int ds_selftest_pebs(void);
-#else
-static inline int ds_selftest_bts(void) { return 0; }
-static inline int ds_selftest_pebs(void) { return 0; }
-#endif
int cpu;
unsigned long flags;
- /* notify the hw-branch tracer so it may disable tracing and
- add the last trace to the trace buffer -
- the earlier this happens, the more useful the trace. */
- trace_hw_branch_oops();
-
oops_enter();
/* racy, but better than risking deadlock. */
static void __kprobes clear_btf(void)
{
- if (test_thread_flag(TIF_DEBUGCTLMSR))
- update_debugctlmsr(0);
+ /* XXX */
}
static void __kprobes restore_btf(void)
{
- if (test_thread_flag(TIF_DEBUGCTLMSR))
- update_debugctlmsr(current->thread.debugctlmsr);
+ /* XXX */
}
void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
#include <asm/idle.h>
#include <asm/uaccess.h>
#include <asm/i387.h>
-#include <asm/ds.h>
#include <asm/debugreg.h>
unsigned long idle_halt;
kmem_cache_free(task_xstate_cachep, tsk->thread.xstate);
tsk->thread.xstate = NULL;
}
-
- WARN(tsk->thread.ds_ctx, "leaking DS context\n");
}
void free_thread_info(struct thread_info *ti)
prev = &prev_p->thread;
next = &next_p->thread;
- if (test_tsk_thread_flag(next_p, TIF_DS_AREA_MSR) ||
- test_tsk_thread_flag(prev_p, TIF_DS_AREA_MSR))
- ds_switch_to(prev_p, next_p);
- else if (next->debugctlmsr != prev->debugctlmsr)
- update_debugctlmsr(next->debugctlmsr);
-
if (test_tsk_thread_flag(prev_p, TIF_NOTSC) ^
test_tsk_thread_flag(next_p, TIF_NOTSC)) {
/* prev and next are different */
#include <asm/cpu.h>
#include <asm/idle.h>
#include <asm/syscalls.h>
-#include <asm/ds.h>
#include <asm/debugreg.h>
asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
kfree(p->thread.io_bitmap_ptr);
p->thread.io_bitmap_max = 0;
}
-
- clear_tsk_thread_flag(p, TIF_DS_AREA_MSR);
- p->thread.ds_ctx = NULL;
-
- clear_tsk_thread_flag(p, TIF_DEBUGCTLMSR);
- p->thread.debugctlmsr = 0;
-
return err;
}
#include <asm/ia32.h>
#include <asm/idle.h>
#include <asm/syscalls.h>
-#include <asm/ds.h>
#include <asm/debugreg.h>
asmlinkage extern void ret_from_fork(void);
if (err)
goto out;
}
-
- clear_tsk_thread_flag(p, TIF_DS_AREA_MSR);
- p->thread.ds_ctx = NULL;
-
- clear_tsk_thread_flag(p, TIF_DEBUGCTLMSR);
- p->thread.debugctlmsr = 0;
-
err = 0;
out:
if (err && p->thread.io_bitmap_ptr) {
/*
* Pentium III FXSR, SSE support
* Gareth Hughes <gareth@valinux.com>, May 2000
- *
- * BTS tracing
- * Markus Metzger <markus.t.metzger@intel.com>, Dec 2007
*/
#include <linux/kernel.h>
#include <linux/audit.h>
#include <linux/seccomp.h>
#include <linux/signal.h>
-#include <linux/workqueue.h>
#include <linux/perf_event.h>
#include <linux/hw_breakpoint.h>
#include <asm/desc.h>
#include <asm/prctl.h>
#include <asm/proto.h>
-#include <asm/ds.h>
#include <asm/hw_breakpoint.h>
#include "tls.h"
0, IO_BITMAP_BYTES);
}
-#ifdef CONFIG_X86_PTRACE_BTS
-/*
- * A branch trace store context.
- *
- * Contexts may only be installed by ptrace_bts_config() and only for
- * ptraced tasks.
- *
- * Contexts are destroyed when the tracee is detached from the tracer.
- * The actual destruction work requires interrupts enabled, so the
- * work is deferred and will be scheduled during __ptrace_unlink().
- *
- * Contexts hold an additional task_struct reference on the traced
- * task, as well as a reference on the tracer's mm.
- *
- * Ptrace already holds a task_struct for the duration of ptrace operations,
- * but since destruction is deferred, it may be executed after both
- * tracer and tracee exited.
- */
-struct bts_context {
- /* The branch trace handle. */
- struct bts_tracer *tracer;
-
- /* The buffer used to store the branch trace and its size. */
- void *buffer;
- unsigned int size;
-
- /* The mm that paid for the above buffer. */
- struct mm_struct *mm;
-
- /* The task this context belongs to. */
- struct task_struct *task;
-
- /* The signal to send on a bts buffer overflow. */
- unsigned int bts_ovfl_signal;
-
- /* The work struct to destroy a context. */
- struct work_struct work;
-};
-
-static int alloc_bts_buffer(struct bts_context *context, unsigned int size)
-{
- void *buffer = NULL;
- int err = -ENOMEM;
-
- err = account_locked_memory(current->mm, current->signal->rlim, size);
- if (err < 0)
- return err;
-
- buffer = kzalloc(size, GFP_KERNEL);
- if (!buffer)
- goto out_refund;
-
- context->buffer = buffer;
- context->size = size;
- context->mm = get_task_mm(current);
-
- return 0;
-
- out_refund:
- refund_locked_memory(current->mm, size);
- return err;
-}
-
-static inline void free_bts_buffer(struct bts_context *context)
-{
- if (!context->buffer)
- return;
-
- kfree(context->buffer);
- context->buffer = NULL;
-
- refund_locked_memory(context->mm, context->size);
- context->size = 0;
-
- mmput(context->mm);
- context->mm = NULL;
-}
-
-static void free_bts_context_work(struct work_struct *w)
-{
- struct bts_context *context;
-
- context = container_of(w, struct bts_context, work);
-
- ds_release_bts(context->tracer);
- put_task_struct(context->task);
- free_bts_buffer(context);
- kfree(context);
-}
-
-static inline void free_bts_context(struct bts_context *context)
-{
- INIT_WORK(&context->work, free_bts_context_work);
- schedule_work(&context->work);
-}
-
-static inline struct bts_context *alloc_bts_context(struct task_struct *task)
-{
- struct bts_context *context = kzalloc(sizeof(*context), GFP_KERNEL);
- if (context) {
- context->task = task;
- task->bts = context;
-
- get_task_struct(task);
- }
-
- return context;
-}
-
-static int ptrace_bts_read_record(struct task_struct *child, size_t index,
- struct bts_struct __user *out)
-{
- struct bts_context *context;
- const struct bts_trace *trace;
- struct bts_struct bts;
- const unsigned char *at;
- int error;
-
- context = child->bts;
- if (!context)
- return -ESRCH;
-
- trace = ds_read_bts(context->tracer);
- if (!trace)
- return -ESRCH;
-
- at = trace->ds.top - ((index + 1) * trace->ds.size);
- if ((void *)at < trace->ds.begin)
- at += (trace->ds.n * trace->ds.size);
-
- if (!trace->read)
- return -EOPNOTSUPP;
-
- error = trace->read(context->tracer, at, &bts);
- if (error < 0)
- return error;
-
- if (copy_to_user(out, &bts, sizeof(bts)))
- return -EFAULT;
-
- return sizeof(bts);
-}
-
-static int ptrace_bts_drain(struct task_struct *child,
- long size,
- struct bts_struct __user *out)
-{
- struct bts_context *context;
- const struct bts_trace *trace;
- const unsigned char *at;
- int error, drained = 0;
-
- context = child->bts;
- if (!context)
- return -ESRCH;
-
- trace = ds_read_bts(context->tracer);
- if (!trace)
- return -ESRCH;
-
- if (!trace->read)
- return -EOPNOTSUPP;
-
- if (size < (trace->ds.top - trace->ds.begin))
- return -EIO;
-
- for (at = trace->ds.begin; (void *)at < trace->ds.top;
- out++, drained++, at += trace->ds.size) {
- struct bts_struct bts;
-
- error = trace->read(context->tracer, at, &bts);
- if (error < 0)
- return error;
-
- if (copy_to_user(out, &bts, sizeof(bts)))
- return -EFAULT;
- }
-
- memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size);
-
- error = ds_reset_bts(context->tracer);
- if (error < 0)
- return error;
-
- return drained;
-}
-
-static int ptrace_bts_config(struct task_struct *child,
- long cfg_size,
- const struct ptrace_bts_config __user *ucfg)
-{
- struct bts_context *context;
- struct ptrace_bts_config cfg;
- unsigned int flags = 0;
-
- if (cfg_size < sizeof(cfg))
- return -EIO;
-
- if (copy_from_user(&cfg, ucfg, sizeof(cfg)))
- return -EFAULT;
-
- context = child->bts;
- if (!context)
- context = alloc_bts_context(child);
- if (!context)
- return -ENOMEM;
-
- if (cfg.flags & PTRACE_BTS_O_SIGNAL) {
- if (!cfg.signal)
- return -EINVAL;
-
- return -EOPNOTSUPP;
- context->bts_ovfl_signal = cfg.signal;
- }
-
- ds_release_bts(context->tracer);
- context->tracer = NULL;
-
- if ((cfg.flags & PTRACE_BTS_O_ALLOC) && (cfg.size != context->size)) {
- int err;
-
- free_bts_buffer(context);
- if (!cfg.size)
- return 0;
-
- err = alloc_bts_buffer(context, cfg.size);
- if (err < 0)
- return err;
- }
-
- if (cfg.flags & PTRACE_BTS_O_TRACE)
- flags |= BTS_USER;
-
- if (cfg.flags & PTRACE_BTS_O_SCHED)
- flags |= BTS_TIMESTAMPS;
-
- context->tracer =
- ds_request_bts_task(child, context->buffer, context->size,
- NULL, (size_t)-1, flags);
- if (unlikely(IS_ERR(context->tracer))) {
- int error = PTR_ERR(context->tracer);
-
- free_bts_buffer(context);
- context->tracer = NULL;
- return error;
- }
-
- return sizeof(cfg);
-}
-
-static int ptrace_bts_status(struct task_struct *child,
- long cfg_size,
- struct ptrace_bts_config __user *ucfg)
-{
- struct bts_context *context;
- const struct bts_trace *trace;
- struct ptrace_bts_config cfg;
-
- context = child->bts;
- if (!context)
- return -ESRCH;
-
- if (cfg_size < sizeof(cfg))
- return -EIO;
-
- trace = ds_read_bts(context->tracer);
- if (!trace)
- return -ESRCH;
-
- memset(&cfg, 0, sizeof(cfg));
- cfg.size = trace->ds.end - trace->ds.begin;
- cfg.signal = context->bts_ovfl_signal;
- cfg.bts_size = sizeof(struct bts_struct);
-
- if (cfg.signal)
- cfg.flags |= PTRACE_BTS_O_SIGNAL;
-
- if (trace->ds.flags & BTS_USER)
- cfg.flags |= PTRACE_BTS_O_TRACE;
-
- if (trace->ds.flags & BTS_TIMESTAMPS)
- cfg.flags |= PTRACE_BTS_O_SCHED;
-
- if (copy_to_user(ucfg, &cfg, sizeof(cfg)))
- return -EFAULT;
-
- return sizeof(cfg);
-}
-
-static int ptrace_bts_clear(struct task_struct *child)
-{
- struct bts_context *context;
- const struct bts_trace *trace;
-
- context = child->bts;
- if (!context)
- return -ESRCH;
-
- trace = ds_read_bts(context->tracer);
- if (!trace)
- return -ESRCH;
-
- memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size);
-
- return ds_reset_bts(context->tracer);
-}
-
-static int ptrace_bts_size(struct task_struct *child)
-{
- struct bts_context *context;
- const struct bts_trace *trace;
-
- context = child->bts;
- if (!context)
- return -ESRCH;
-
- trace = ds_read_bts(context->tracer);
- if (!trace)
- return -ESRCH;
-
- return (trace->ds.top - trace->ds.begin) / trace->ds.size;
-}
-
-/*
- * Called from __ptrace_unlink() after the child has been moved back
- * to its original parent.
- */
-void ptrace_bts_untrace(struct task_struct *child)
-{
- if (unlikely(child->bts)) {
- free_bts_context(child->bts);
- child->bts = NULL;
- }
-}
-#endif /* CONFIG_X86_PTRACE_BTS */
-
/*
* Called by kernel/ptrace.c when detaching..
*
break;
#endif
- /*
- * These bits need more cooking - not enabled yet:
- */
-#ifdef CONFIG_X86_PTRACE_BTS
- case PTRACE_BTS_CONFIG:
- ret = ptrace_bts_config
- (child, data, (struct ptrace_bts_config __user *)addr);
- break;
-
- case PTRACE_BTS_STATUS:
- ret = ptrace_bts_status
- (child, data, (struct ptrace_bts_config __user *)addr);
- break;
-
- case PTRACE_BTS_SIZE:
- ret = ptrace_bts_size(child);
- break;
-
- case PTRACE_BTS_GET:
- ret = ptrace_bts_read_record
- (child, data, (struct bts_struct __user *) addr);
- break;
-
- case PTRACE_BTS_CLEAR:
- ret = ptrace_bts_clear(child);
- break;
-
- case PTRACE_BTS_DRAIN:
- ret = ptrace_bts_drain
- (child, data, (struct bts_struct __user *) addr);
- break;
-#endif /* CONFIG_X86_PTRACE_BTS */
-
default:
ret = ptrace_request(child, request, addr, data);
break;
case PTRACE_GET_THREAD_AREA:
case PTRACE_SET_THREAD_AREA:
-#ifdef CONFIG_X86_PTRACE_BTS
- case PTRACE_BTS_CONFIG:
- case PTRACE_BTS_STATUS:
- case PTRACE_BTS_SIZE:
- case PTRACE_BTS_GET:
- case PTRACE_BTS_CLEAR:
- case PTRACE_BTS_DRAIN:
-#endif /* CONFIG_X86_PTRACE_BTS */
return arch_ptrace(child, request, addr, data);
default:
return 1;
}
-/*
- * Install this value in MSR_IA32_DEBUGCTLMSR whenever child is running.
- */
-static void write_debugctlmsr(struct task_struct *child, unsigned long val)
-{
- if (child->thread.debugctlmsr == val)
- return;
-
- child->thread.debugctlmsr = val;
-
- if (child != current)
- return;
-
- update_debugctlmsr(val);
-}
-
/*
* Enable single or block step.
*/
* So noone should try to use debugger block stepping in a program
* that uses user-mode single stepping itself.
*/
- if (enable_single_step(child) && block) {
- set_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
- write_debugctlmsr(child,
- child->thread.debugctlmsr | DEBUGCTLMSR_BTF);
- } else {
- write_debugctlmsr(child,
- child->thread.debugctlmsr & ~DEBUGCTLMSR_BTF);
-
- if (!child->thread.debugctlmsr)
- clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
- }
+ if (!enable_single_step(child))
+ return;
+ /* XXX */
}
void user_enable_single_step(struct task_struct *child)
/*
* Make sure block stepping (BTF) is disabled.
*/
- write_debugctlmsr(child,
- child->thread.debugctlmsr & ~DEBUGCTLMSR_BTF);
-
- if (!child->thread.debugctlmsr)
- clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
+ /* XXX */
/* Always clear TIF_SINGLESTEP... */
clear_tsk_thread_flag(child, TIF_SINGLESTEP);
/* DR6 may or may not be cleared by the CPU */
set_debugreg(0, 6);
- /*
- * The processor cleared BTF, so don't mark that we need it set.
- */
- clear_tsk_thread_flag(tsk, TIF_DEBUGCTLMSR);
- tsk->thread.debugctlmsr = 0;
/* Store the virtualized DR6 value */
tsk->thread.debugreg6 = dr6;
#define INIT_TRACE_RECURSION
#endif
-#ifdef CONFIG_HW_BRANCH_TRACER
-
-void trace_hw_branch(u64 from, u64 to);
-void trace_hw_branch_oops(void);
-
-#else /* CONFIG_HW_BRANCH_TRACER */
-
-static inline void trace_hw_branch(u64 from, u64 to) {}
-static inline void trace_hw_branch_oops(void) {}
-
-#endif /* CONFIG_HW_BRANCH_TRACER */
-
#ifdef CONFIG_FTRACE_SYSCALLS
unsigned long arch_syscall_addr(int nr);
struct file_ra_state;
struct user_struct;
struct writeback_control;
-struct rlimit;
#ifndef CONFIG_DISCONTIGMEM /* Don't use mapnrs, do it properly */
extern unsigned long max_mapnr;
int vmemmap_populate(struct page *start_page, unsigned long pages, int node);
void vmemmap_populate_print_last(void);
-extern int account_locked_memory(struct mm_struct *mm, struct rlimit *rlim,
- size_t size);
-extern void refund_locked_memory(struct mm_struct *mm, size_t size);
enum mf_flags {
MF_COUNT_INCREASED = 1 << 0,
#define arch_ptrace_stop(code, info) do { } while (0)
#endif
-#ifndef arch_ptrace_untrace
-/*
- * Do machine-specific work before untracing child.
- *
- * This is called for a normal detach as well as from ptrace_exit()
- * when the tracing task dies.
- *
- * Called with write_lock(&tasklist_lock) held.
- */
-#define arch_ptrace_untrace(task) do { } while (0)
-#endif
-
extern int task_current_syscall(struct task_struct *target, long *callno,
unsigned long args[6], unsigned int maxargs,
unsigned long *sp, unsigned long *pc);
struct robust_list_head;
struct bio_list;
struct fs_struct;
-struct bts_context;
struct perf_event_context;
/*
struct list_head ptraced;
struct list_head ptrace_entry;
- /*
- * This is the tracer handle for the ptrace BTS extension.
- * This field actually belongs to the ptracer task.
- */
- struct bts_context *bts;
-
/* PID/PID hash table linkage. */
struct pid_link pids[PIDTYPE_MAX];
struct list_head thread_group;
extern char *get_task_comm(char *to, struct task_struct *tsk);
#ifdef CONFIG_SMP
-extern void wait_task_context_switch(struct task_struct *p);
extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
#else
-static inline void wait_task_context_switch(struct task_struct *p) {}
static inline unsigned long wait_task_inactive(struct task_struct *p,
long match_state)
{
p->memcg_batch.do_batch = 0;
p->memcg_batch.memcg = NULL;
#endif
-
- p->bts = NULL;
-
p->stack_start = stack_start;
/* Perform scheduler related setup. Assign this task to a CPU. */
child->parent = child->real_parent;
list_del_init(&child->ptrace_entry);
- arch_ptrace_untrace(child);
if (task_is_traced(child))
ptrace_untrace(child);
}
return 1;
}
-/*
- * wait_task_context_switch - wait for a thread to complete at least one
- * context switch.
- *
- * @p must not be current.
- */
-void wait_task_context_switch(struct task_struct *p)
-{
- unsigned long nvcsw, nivcsw, flags;
- int running;
- struct rq *rq;
-
- nvcsw = p->nvcsw;
- nivcsw = p->nivcsw;
- for (;;) {
- /*
- * The runqueue is assigned before the actual context
- * switch. We need to take the runqueue lock.
- *
- * We could check initially without the lock but it is
- * very likely that we need to take the lock in every
- * iteration.
- */
- rq = task_rq_lock(p, &flags);
- running = task_running(rq, p);
- task_rq_unlock(rq, &flags);
-
- if (likely(!running))
- break;
- /*
- * The switch count is incremented before the actual
- * context switch. We thus wait for two switches to be
- * sure at least one completed.
- */
- if ((p->nvcsw - nvcsw) > 1)
- break;
- if ((p->nivcsw - nivcsw) > 1)
- break;
-
- cpu_relax();
- }
-}
-
/*
* wait_task_inactive - wait for a thread to unschedule.
*
help
See Documentation/trace/ftrace-design.txt
-config HAVE_HW_BRANCH_TRACER
- bool
-
config HAVE_SYSCALL_TRACEPOINTS
bool
help
Say N if unsure.
-config HW_BRANCH_TRACER
- depends on HAVE_HW_BRANCH_TRACER
- bool "Trace hw branches"
- select GENERIC_TRACER
- help
- This tracer records all branches on the system in a circular
- buffer, giving access to the last N branches for each cpu.
-
config KMEMTRACE
bool "Trace SLAB allocations"
select GENERIC_TRACER
obj-$(CONFIG_BOOT_TRACER) += trace_boot.o
obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += trace_functions_graph.o
obj-$(CONFIG_TRACE_BRANCH_PROFILING) += trace_branch.o
-obj-$(CONFIG_HW_BRANCH_TRACER) += trace_hw_branches.o
obj-$(CONFIG_KMEMTRACE) += kmemtrace.o
obj-$(CONFIG_WORKQUEUE_TRACER) += trace_workqueue.o
obj-$(CONFIG_BLK_DEV_IO_TRACE) += blktrace.o
TRACE_GRAPH_RET,
TRACE_GRAPH_ENT,
TRACE_USER_STACK,
- TRACE_HW_BRANCHES,
TRACE_KMEM_ALLOC,
TRACE_KMEM_FREE,
TRACE_BLK,
TRACE_GRAPH_ENT); \
IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry, \
TRACE_GRAPH_RET); \
- IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\
IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry, \
TRACE_KMEM_ALLOC); \
IF_ASSIGN(var, ent, struct kmemtrace_free_entry, \
struct trace_array *tr);
extern int trace_selftest_startup_branch(struct tracer *trace,
struct trace_array *tr);
-extern int trace_selftest_startup_hw_branches(struct tracer *trace,
- struct trace_array *tr);
extern int trace_selftest_startup_ksym(struct tracer *trace,
struct trace_array *tr);
#endif /* CONFIG_FTRACE_STARTUP_TEST */
__entry->func, __entry->file, __entry->correct)
);
-FTRACE_ENTRY(hw_branch, hw_branch_entry,
-
- TRACE_HW_BRANCHES,
-
- F_STRUCT(
- __field( u64, from )
- __field( u64, to )
- ),
-
- F_printk("from: %llx to: %llx", __entry->from, __entry->to)
-);
-
FTRACE_ENTRY(kmem_alloc, kmemtrace_alloc_entry,
TRACE_KMEM_ALLOC,
+++ /dev/null
-/*
- * h/w branch tracer for x86 based on BTS
- *
- * Copyright (C) 2008-2009 Intel Corporation.
- * Markus Metzger <markus.t.metzger@gmail.com>, 2008-2009
- */
-#include <linux/kallsyms.h>
-#include <linux/debugfs.h>
-#include <linux/ftrace.h>
-#include <linux/module.h>
-#include <linux/cpu.h>
-#include <linux/smp.h>
-#include <linux/fs.h>
-
-#include <asm/ds.h>
-
-#include "trace_output.h"
-#include "trace.h"
-
-
-#define BTS_BUFFER_SIZE (1 << 13)
-
-static DEFINE_PER_CPU(struct bts_tracer *, hwb_tracer);
-static DEFINE_PER_CPU(unsigned char[BTS_BUFFER_SIZE], hwb_buffer);
-
-#define this_tracer per_cpu(hwb_tracer, smp_processor_id())
-
-static int trace_hw_branches_enabled __read_mostly;
-static int trace_hw_branches_suspended __read_mostly;
-static struct trace_array *hw_branch_trace __read_mostly;
-
-
-static void bts_trace_init_cpu(int cpu)
-{
- per_cpu(hwb_tracer, cpu) =
- ds_request_bts_cpu(cpu, per_cpu(hwb_buffer, cpu),
- BTS_BUFFER_SIZE, NULL, (size_t)-1,
- BTS_KERNEL);
-
- if (IS_ERR(per_cpu(hwb_tracer, cpu)))
- per_cpu(hwb_tracer, cpu) = NULL;
-}
-
-static int bts_trace_init(struct trace_array *tr)
-{
- int cpu;
-
- hw_branch_trace = tr;
- trace_hw_branches_enabled = 0;
-
- get_online_cpus();
- for_each_online_cpu(cpu) {
- bts_trace_init_cpu(cpu);
-
- if (likely(per_cpu(hwb_tracer, cpu)))
- trace_hw_branches_enabled = 1;
- }
- trace_hw_branches_suspended = 0;
- put_online_cpus();
-
- /* If we could not enable tracing on a single cpu, we fail. */
- return trace_hw_branches_enabled ? 0 : -EOPNOTSUPP;
-}
-
-static void bts_trace_reset(struct trace_array *tr)
-{
- int cpu;
-
- get_online_cpus();
- for_each_online_cpu(cpu) {
- if (likely(per_cpu(hwb_tracer, cpu))) {
- ds_release_bts(per_cpu(hwb_tracer, cpu));
- per_cpu(hwb_tracer, cpu) = NULL;
- }
- }
- trace_hw_branches_enabled = 0;
- trace_hw_branches_suspended = 0;
- put_online_cpus();
-}
-
-static void bts_trace_start(struct trace_array *tr)
-{
- int cpu;
-
- get_online_cpus();
- for_each_online_cpu(cpu)
- if (likely(per_cpu(hwb_tracer, cpu)))
- ds_resume_bts(per_cpu(hwb_tracer, cpu));
- trace_hw_branches_suspended = 0;
- put_online_cpus();
-}
-
-static void bts_trace_stop(struct trace_array *tr)
-{
- int cpu;
-
- get_online_cpus();
- for_each_online_cpu(cpu)
- if (likely(per_cpu(hwb_tracer, cpu)))
- ds_suspend_bts(per_cpu(hwb_tracer, cpu));
- trace_hw_branches_suspended = 1;
- put_online_cpus();
-}
-
-static int __cpuinit bts_hotcpu_handler(struct notifier_block *nfb,
- unsigned long action, void *hcpu)
-{
- int cpu = (long)hcpu;
-
- switch (action) {
- case CPU_ONLINE:
- case CPU_DOWN_FAILED:
- /* The notification is sent with interrupts enabled. */
- if (trace_hw_branches_enabled) {
- bts_trace_init_cpu(cpu);
-
- if (trace_hw_branches_suspended &&
- likely(per_cpu(hwb_tracer, cpu)))
- ds_suspend_bts(per_cpu(hwb_tracer, cpu));
- }
- break;
-
- case CPU_DOWN_PREPARE:
- /* The notification is sent with interrupts enabled. */
- if (likely(per_cpu(hwb_tracer, cpu))) {
- ds_release_bts(per_cpu(hwb_tracer, cpu));
- per_cpu(hwb_tracer, cpu) = NULL;
- }
- }
-
- return NOTIFY_DONE;
-}
-
-static struct notifier_block bts_hotcpu_notifier __cpuinitdata = {
- .notifier_call = bts_hotcpu_handler
-};
-
-static void bts_trace_print_header(struct seq_file *m)
-{
- seq_puts(m, "# CPU# TO <- FROM\n");
-}
-
-static enum print_line_t bts_trace_print_line(struct trace_iterator *iter)
-{
- unsigned long symflags = TRACE_ITER_SYM_OFFSET;
- struct trace_entry *entry = iter->ent;
- struct trace_seq *seq = &iter->seq;
- struct hw_branch_entry *it;
-
- trace_assign_type(it, entry);
-
- if (entry->type == TRACE_HW_BRANCHES) {
- if (trace_seq_printf(seq, "%4d ", iter->cpu) &&
- seq_print_ip_sym(seq, it->to, symflags) &&
- trace_seq_printf(seq, "\t <- ") &&
- seq_print_ip_sym(seq, it->from, symflags) &&
- trace_seq_printf(seq, "\n"))
- return TRACE_TYPE_HANDLED;
- return TRACE_TYPE_PARTIAL_LINE;
- }
- return TRACE_TYPE_UNHANDLED;
-}
-
-void trace_hw_branch(u64 from, u64 to)
-{
- struct ftrace_event_call *call = &event_hw_branch;
- struct trace_array *tr = hw_branch_trace;
- struct ring_buffer_event *event;
- struct ring_buffer *buf;
- struct hw_branch_entry *entry;
- unsigned long irq1;
- int cpu;
-
- if (unlikely(!tr))
- return;
-
- if (unlikely(!trace_hw_branches_enabled))
- return;
-
- local_irq_save(irq1);
- cpu = raw_smp_processor_id();
- if (atomic_inc_return(&tr->data[cpu]->disabled) != 1)
- goto out;
-
- buf = tr->buffer;
- event = trace_buffer_lock_reserve(buf, TRACE_HW_BRANCHES,
- sizeof(*entry), 0, 0);
- if (!event)
- goto out;
- entry = ring_buffer_event_data(event);
- tracing_generic_entry_update(&entry->ent, 0, from);
- entry->ent.type = TRACE_HW_BRANCHES;
- entry->from = from;
- entry->to = to;
- if (!filter_check_discard(call, entry, buf, event))
- trace_buffer_unlock_commit(buf, event, 0, 0);
-
- out:
- atomic_dec(&tr->data[cpu]->disabled);
- local_irq_restore(irq1);
-}
-
-static void trace_bts_at(const struct bts_trace *trace, void *at)
-{
- struct bts_struct bts;
- int err = 0;
-
- WARN_ON_ONCE(!trace->read);
- if (!trace->read)
- return;
-
- err = trace->read(this_tracer, at, &bts);
- if (err < 0)
- return;
-
- switch (bts.qualifier) {
- case BTS_BRANCH:
- trace_hw_branch(bts.variant.lbr.from, bts.variant.lbr.to);
- break;
- }
-}
-
-/*
- * Collect the trace on the current cpu and write it into the ftrace buffer.
- *
- * pre: tracing must be suspended on the current cpu
- */
-static void trace_bts_cpu(void *arg)
-{
- struct trace_array *tr = (struct trace_array *)arg;
- const struct bts_trace *trace;
- unsigned char *at;
-
- if (unlikely(!tr))
- return;
-
- if (unlikely(atomic_read(&tr->data[raw_smp_processor_id()]->disabled)))
- return;
-
- if (unlikely(!this_tracer))
- return;
-
- trace = ds_read_bts(this_tracer);
- if (!trace)
- return;
-
- for (at = trace->ds.top; (void *)at < trace->ds.end;
- at += trace->ds.size)
- trace_bts_at(trace, at);
-
- for (at = trace->ds.begin; (void *)at < trace->ds.top;
- at += trace->ds.size)
- trace_bts_at(trace, at);
-}
-
-static void trace_bts_prepare(struct trace_iterator *iter)
-{
- int cpu;
-
- get_online_cpus();
- for_each_online_cpu(cpu)
- if (likely(per_cpu(hwb_tracer, cpu)))
- ds_suspend_bts(per_cpu(hwb_tracer, cpu));
- /*
- * We need to collect the trace on the respective cpu since ftrace
- * implicitly adds the record for the current cpu.
- * Once that is more flexible, we could collect the data from any cpu.
- */
- on_each_cpu(trace_bts_cpu, iter->tr, 1);
-
- for_each_online_cpu(cpu)
- if (likely(per_cpu(hwb_tracer, cpu)))
- ds_resume_bts(per_cpu(hwb_tracer, cpu));
- put_online_cpus();
-}
-
-static void trace_bts_close(struct trace_iterator *iter)
-{
- tracing_reset_online_cpus(iter->tr);
-}
-
-void trace_hw_branch_oops(void)
-{
- if (this_tracer) {
- ds_suspend_bts_noirq(this_tracer);
- trace_bts_cpu(hw_branch_trace);
- ds_resume_bts_noirq(this_tracer);
- }
-}
-
-struct tracer bts_tracer __read_mostly =
-{
- .name = "hw-branch-tracer",
- .init = bts_trace_init,
- .reset = bts_trace_reset,
- .print_header = bts_trace_print_header,
- .print_line = bts_trace_print_line,
- .start = bts_trace_start,
- .stop = bts_trace_stop,
- .open = trace_bts_prepare,
- .close = trace_bts_close,
-#ifdef CONFIG_FTRACE_SELFTEST
- .selftest = trace_selftest_startup_hw_branches,
-#endif /* CONFIG_FTRACE_SELFTEST */
-};
-
-__init static int init_bts_trace(void)
-{
- register_hotcpu_notifier(&bts_hotcpu_notifier);
- return register_tracer(&bts_tracer);
-}
-device_initcall(init_bts_trace);
case TRACE_BRANCH:
case TRACE_GRAPH_ENT:
case TRACE_GRAPH_RET:
- case TRACE_HW_BRANCHES:
case TRACE_KSYM:
return 1;
}
}
#endif /* CONFIG_BRANCH_TRACER */
-#ifdef CONFIG_HW_BRANCH_TRACER
-int
-trace_selftest_startup_hw_branches(struct tracer *trace,
- struct trace_array *tr)
-{
- struct trace_iterator *iter;
- struct tracer tracer;
- unsigned long count;
- int ret;
-
- if (!trace->open) {
- printk(KERN_CONT "missing open function...");
- return -1;
- }
-
- ret = tracer_init(trace, tr);
- if (ret) {
- warn_failed_init_tracer(trace, ret);
- return ret;
- }
-
- /*
- * The hw-branch tracer needs to collect the trace from the various
- * cpu trace buffers - before tracing is stopped.
- */
- iter = kzalloc(sizeof(*iter), GFP_KERNEL);
- if (!iter)
- return -ENOMEM;
-
- memcpy(&tracer, trace, sizeof(tracer));
-
- iter->trace = &tracer;
- iter->tr = tr;
- iter->pos = -1;
- mutex_init(&iter->mutex);
-
- trace->open(iter);
-
- mutex_destroy(&iter->mutex);
- kfree(iter);
-
- tracing_stop();
-
- ret = trace_test_buffer(tr, &count);
- trace->reset(tr);
- tracing_start();
-
- if (!ret && !count) {
- printk(KERN_CONT "no entries found..");
- ret = -1;
- }
-
- return ret;
-}
-#endif /* CONFIG_HW_BRANCH_TRACER */
-
#ifdef CONFIG_KSYM_TRACER
static int ksym_selftest_dummy;
spin_unlock(&shmlock_user_lock);
free_uid(user);
}
-
-int account_locked_memory(struct mm_struct *mm, struct rlimit *rlim,
- size_t size)
-{
- unsigned long lim, vm, pgsz;
- int error = -ENOMEM;
-
- pgsz = PAGE_ALIGN(size) >> PAGE_SHIFT;
-
- down_write(&mm->mmap_sem);
-
- lim = ACCESS_ONCE(rlim[RLIMIT_AS].rlim_cur) >> PAGE_SHIFT;
- vm = mm->total_vm + pgsz;
- if (lim < vm)
- goto out;
-
- lim = ACCESS_ONCE(rlim[RLIMIT_MEMLOCK].rlim_cur) >> PAGE_SHIFT;
- vm = mm->locked_vm + pgsz;
- if (lim < vm)
- goto out;
-
- mm->total_vm += pgsz;
- mm->locked_vm += pgsz;
-
- error = 0;
- out:
- up_write(&mm->mmap_sem);
- return error;
-}
-
-void refund_locked_memory(struct mm_struct *mm, size_t size)
-{
- unsigned long pgsz = PAGE_ALIGN(size) >> PAGE_SHIFT;
-
- down_write(&mm->mmap_sem);
-
- mm->total_vm -= pgsz;
- mm->locked_vm -= pgsz;
-
- up_write(&mm->mmap_sem);
-}
projects / linux-beck.git / commitdiff