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x86, bts: provide in-kernel branch-trace interface

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Impact: cleanup

Move the BTS bits from ptrace.c into ds.c.

Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Markus Metzger 2008-12-11 13:49:59 +01:00 committed by Ingo Molnar
parent b0884e25fe
commit c2724775ce
10 changed files with 909 additions and 969 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

241
arch/x86/include/asm/ds.h
View File

@ -6,13 +6,13 @@
* precise-event based sampling (PEBS).
*
* It manages:
* - per-thread and per-cpu allocation of BTS and PEBS
* - DS and BTS hardware configuration
* - buffer overflow handling (to be done)
* - buffer access
*
* It assumes:
* - get_task_struct on all traced tasks
* - current is allowed to trace tasks
* It does not do:
* - security checking (is the caller allowed to trace the task)
* - buffer allocation (memory accounting)
*
*
* Copyright (C) 2007-2008 Intel Corporation.
@ -31,6 +31,7 @@
#ifdef CONFIG_X86_DS
struct task_struct;
struct ds_context;
struct ds_tracer;
struct bts_tracer;
struct pebs_tracer;
@ -38,6 +39,38 @@ 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
*
@ -58,92 +91,135 @@ typedef void (*pebs_ovfl_callback_t)(struct pebs_tracer *);
* 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(struct task_struct *task,
void *base, size_t size,
bts_ovfl_callback_t ovfl, size_t th);
bts_ovfl_callback_t ovfl,
size_t th, unsigned int flags);
extern struct pebs_tracer *ds_request_pebs(struct task_struct *task,
void *base, size_t size,
pebs_ovfl_callback_t ovfl,
size_t th);
size_t th, unsigned int flags);
/*
* Release BTS or PEBS resources
*
* Returns 0 on success; -Eerrno otherwise
* Suspend and resume BTS or PEBS tracing
*
* tracer: the tracer handle returned from ds_request_~()
*/
extern int ds_release_bts(struct bts_tracer *tracer);
extern int ds_release_pebs(struct pebs_tracer *tracer);
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);
/*
* Get the (array) index of the write pointer.
* (assuming an array of BTS/PEBS records)
* The raw DS buffer state as it is used for BTS and PEBS recording.
*
* Returns 0 on success; -Eerrno on error
*
* tracer: the tracer handle returned from ds_request_~()
* pos (out): will hold the result
* This is the low-level, arch-dependent interface for working
* directly on the raw trace data.
*/
extern int ds_get_bts_index(struct bts_tracer *tracer, size_t *pos);
extern int ds_get_pebs_index(struct pebs_tracer *tracer, size_t *pos);
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;
};
/*
* Get the (array) index one record beyond the end of the array.
* (assuming an array of BTS/PEBS records)
*
* Returns 0 on success; -Eerrno on error
*
* tracer: the tracer handle returned from ds_request_~()
* pos (out): will hold the result
* An arch-independent view on branch trace data.
*/
extern int ds_get_bts_end(struct bts_tracer *tracer, size_t *pos);
extern int ds_get_pebs_end(struct pebs_tracer *tracer, size_t *pos);
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 jiffies;
pid_t pid;
} timestamp;
} variant;
};
/*
* Provide a pointer to the BTS/PEBS record at parameter index.
* (assuming an array of BTS/PEBS records)
* The BTS state.
*
* The pointer points directly into the buffer. The user is
* responsible for copying the record.
*
* Returns the size of a single record on success; -Eerrno on error
*
* tracer: the tracer handle returned from ds_request_~()
* index: the index of the requested record
* record (out): pointer to the requested record
* This gives access to the raw DS state and adds functions to provide
* an arch-independent view of the BTS data.
*/
extern int ds_access_bts(struct bts_tracer *tracer,
size_t index, const void **record);
extern int ds_access_pebs(struct pebs_tracer *tracer,
size_t index, const void **record);
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);
};
/*
* Write one or more BTS/PEBS records at the write pointer index and
* advance the write pointer.
* The PEBS state.
*
* If size is not a multiple of the record size, trailing bytes are
* zeroed out.
* This gives access to the raw DS state and the PEBS-specific counter
* reset value.
*/
struct pebs_trace {
struct ds_trace ds;
/* the PEBS reset value */
unsigned long long reset_value;
};
/*
* Read the BTS or PEBS trace.
*
* May result in one or more overflow notifications.
* Returns a view on the trace collected for the parameter tracer.
*
* If called during overflow handling, that is, with index >=
* interrupt threshold, the write will wrap around.
*
* An overflow notification is given if and when the interrupt
* threshold is reached during or after the write.
*
* Returns the number of bytes written or -Eerrno.
* 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_~()
* buffer: the buffer to write
* size: the size of the buffer
*/
extern int ds_write_bts(struct bts_tracer *tracer,
const void *buffer, size_t size);
extern int ds_write_pebs(struct pebs_tracer *tracer,
const void *buffer, size_t size);
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.
@ -155,27 +231,6 @@ extern int ds_write_pebs(struct pebs_tracer *tracer,
extern int ds_reset_bts(struct bts_tracer *tracer);
extern int ds_reset_pebs(struct pebs_tracer *tracer);
/*
* Clear the BTS/PEBS buffer and reset the write pointer.
* The entire buffer will be zeroed out.
*
* Returns 0 on success; -Eerrno on error
*
* tracer: the tracer handle returned from ds_request_~()
*/
extern int ds_clear_bts(struct bts_tracer *tracer);
extern int ds_clear_pebs(struct pebs_tracer *tracer);
/*
* Provide the PEBS counter reset value.
*
* Returns 0 on success; -Eerrno on error
*
* tracer: the tracer handle returned from ds_request_pebs()
* value (out): the counter reset value
*/
extern int ds_get_pebs_reset(struct pebs_tracer *tracer, u64 *value);
/*
* Set the PEBS counter reset value.
*
@ -192,35 +247,17 @@ extern int ds_set_pebs_reset(struct pebs_tracer *tracer, u64 value);
struct cpuinfo_x86;
extern void __cpuinit ds_init_intel(struct cpuinfo_x86 *);
/*
* The DS context - part of struct thread_struct.
* Context switch work
*/
#define MAX_SIZEOF_DS (12 * 8)
struct ds_context {
/* pointer to 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 ds_tracer *owner[2];
/* use count */
unsigned long count;
/* a pointer to the context location inside the thread_struct
* or the per_cpu context array */
struct ds_context **this;
/* a pointer to the task owning this context, or NULL, if the
* context is owned by a cpu */
struct task_struct *task;
};
/* called by exit_thread() to free leftover contexts */
extern void ds_free(struct ds_context *context);
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 */

13
arch/x86/include/asm/processor.h
View File

@ -752,6 +752,19 @@ extern void switch_to_new_gdt(void);
extern void cpu_init(void);
extern void init_gdt(int cpu);
static inline unsigned long get_debugctlmsr(void)
{
unsigned long debugctlmsr = 0;
#ifndef CONFIG_X86_DEBUGCTLMSR
if (boot_cpu_data.x86 < 6)
return 0;
#endif
rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctlmsr);
return debugctlmsr;
}
static inline void update_debugctlmsr(unsigned long debugctlmsr)
{
#ifndef CONFIG_X86_DEBUGCTLMSR

36
arch/x86/include/asm/ptrace.h
View File

@ -6,7 +6,6 @@
#include <asm/processor-flags.h>
#ifdef __KERNEL__
#include <asm/ds.h> /* the DS BTS struct is used for ptrace too */
#include <asm/segment.h>
#endif
@ -128,34 +127,6 @@ struct pt_regs {
#endif /* !__i386__ */
#ifdef CONFIG_X86_PTRACE_BTS
/* a branch trace record entry
*
* In order to unify the interface between various processor versions,
* we use the below data structure for all processors.
*/
enum bts_qualifier {
BTS_INVALID = 0,
BTS_BRANCH,
BTS_TASK_ARRIVES,
BTS_TASK_DEPARTS
};
struct bts_struct {
__u64 qualifier;
union {
/* BTS_BRANCH */
struct {
__u64 from_ip;
__u64 to_ip;
} lbr;
/* BTS_TASK_ARRIVES or
BTS_TASK_DEPARTS */
__u64 jiffies;
} variant;
};
#endif /* CONFIG_X86_PTRACE_BTS */
#ifdef __KERNEL__
#include <linux/init.h>
@ -163,13 +134,6 @@ struct bts_struct {
struct cpuinfo_x86;
struct task_struct;
#ifdef CONFIG_X86_PTRACE_BTS
extern void __cpuinit ptrace_bts_init_intel(struct cpuinfo_x86 *);
extern void ptrace_bts_take_timestamp(struct task_struct *, enum bts_qualifier);
#else
#define ptrace_bts_init_intel(config) do {} while (0)
#endif /* CONFIG_X86_PTRACE_BTS */
extern unsigned long profile_pc(struct pt_regs *regs);
extern unsigned long

5
arch/x86/include/asm/thread_info.h
View File

@ -93,7 +93,6 @@ struct thread_info {
#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_BTS_TRACE_TS 27 /* record scheduling event timestamps */
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
@ -115,7 +114,6 @@ struct thread_info {
#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_BTS_TRACE_TS (1 << TIF_BTS_TRACE_TS)
/* work to do in syscall_trace_enter() */
#define _TIF_WORK_SYSCALL_ENTRY \
@ -141,8 +139,7 @@ struct thread_info {
/* flags to check in __switch_to() */
#define _TIF_WORK_CTXSW \
(_TIF_IO_BITMAP|_TIF_DEBUGCTLMSR|_TIF_DS_AREA_MSR|_TIF_BTS_TRACE_TS| \
_TIF_NOTSC)
(_TIF_IO_BITMAP|_TIF_DEBUGCTLMSR|_TIF_DS_AREA_MSR|_TIF_NOTSC)
#define _TIF_WORK_CTXSW_PREV _TIF_WORK_CTXSW
#define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW|_TIF_DEBUG)

4
arch/x86/kernel/cpu/intel.c
View File

@ -11,7 +11,6 @@
#include <asm/pgtable.h>
#include <asm/msr.h>
#include <asm/uaccess.h>
#include <asm/ptrace.h>
#include <asm/ds.h>
#include <asm/bugs.h>
@ -309,9 +308,6 @@ static void __cpuinit init_intel(struct cpuinfo_x86 *c)
set_cpu_cap(c, X86_FEATURE_P3);
#endif
if (cpu_has_bts)
ptrace_bts_init_intel(c);
detect_extended_topology(c);
if (!cpu_has(c, X86_FEATURE_XTOPOLOGY)) {
/*

1035
arch/x86/kernel/ds.c
View File

File diff suppressed because it is too large Load Diff

59
arch/x86/kernel/process_32.c
View File

@ -252,11 +252,14 @@ void exit_thread(void)
put_cpu();
}
#ifdef CONFIG_X86_DS
/* Free any DS contexts that have not been properly released. */
if (unlikely(current->thread.ds_ctx)) {
/* we clear debugctl to make sure DS is not used. */
update_debugctlmsr(0);
ds_free(current->thread.ds_ctx);
/* Free any BTS tracers that have not been properly released. */
if (unlikely(current->bts)) {
ds_release_bts(current->bts);
current->bts = NULL;
kfree(current->bts_buffer);
current->bts_buffer = NULL;
current->bts_size = 0;
}
#endif /* CONFIG_X86_DS */
}
@ -420,48 +423,19 @@ int set_tsc_mode(unsigned int val)
return 0;
}
#ifdef CONFIG_X86_DS
static int update_debugctl(struct thread_struct *prev,
struct thread_struct *next, unsigned long debugctl)
{
unsigned long ds_prev = 0;
unsigned long ds_next = 0;
if (prev->ds_ctx)
ds_prev = (unsigned long)prev->ds_ctx->ds;
if (next->ds_ctx)
ds_next = (unsigned long)next->ds_ctx->ds;
if (ds_next != ds_prev) {
/* we clear debugctl to make sure DS
* is not in use when we change it */
debugctl = 0;
update_debugctlmsr(0);
wrmsr(MSR_IA32_DS_AREA, ds_next, 0);
}
return debugctl;
}
#else
static int update_debugctl(struct thread_struct *prev,
struct thread_struct *next, unsigned long debugctl)
{
return debugctl;
}
#endif /* CONFIG_X86_DS */
static noinline void
__switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
struct tss_struct *tss)
{
struct thread_struct *prev, *next;
unsigned long debugctl;
prev = &prev_p->thread;
next = &next_p->thread;
debugctl = update_debugctl(prev, next, prev->debugctlmsr);
if (next->debugctlmsr != debugctl)
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(next_p, TIF_DEBUG)) {
@ -483,15 +457,6 @@ __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
hard_enable_TSC();
}
#ifdef CONFIG_X86_PTRACE_BTS
if (test_tsk_thread_flag(prev_p, TIF_BTS_TRACE_TS))
ptrace_bts_take_timestamp(prev_p, BTS_TASK_DEPARTS);
if (test_tsk_thread_flag(next_p, TIF_BTS_TRACE_TS))
ptrace_bts_take_timestamp(next_p, BTS_TASK_ARRIVES);
#endif /* CONFIG_X86_PTRACE_BTS */
if (!test_tsk_thread_flag(next_p, TIF_IO_BITMAP)) {
/*
* Disable the bitmap via an invalid offset. We still cache

50
arch/x86/kernel/process_64.c
View File

@ -237,11 +237,14 @@ void exit_thread(void)
put_cpu();
}
#ifdef CONFIG_X86_DS
/* Free any DS contexts that have not been properly released. */
if (unlikely(t->ds_ctx)) {
/* we clear debugctl to make sure DS is not used. */
update_debugctlmsr(0);
ds_free(t->ds_ctx);
/* Free any BTS tracers that have not been properly released. */
if (unlikely(current->bts)) {
ds_release_bts(current->bts);
current->bts = NULL;
kfree(current->bts_buffer);
current->bts_buffer = NULL;
current->bts_size = 0;
}
#endif /* CONFIG_X86_DS */
}
@ -471,35 +474,14 @@ static inline void __switch_to_xtra(struct task_struct *prev_p,
struct tss_struct *tss)
{
struct thread_struct *prev, *next;
unsigned long debugctl;
prev = &prev_p->thread,
next = &next_p->thread;
debugctl = prev->debugctlmsr;
#ifdef CONFIG_X86_DS
{
unsigned long ds_prev = 0, ds_next = 0;
if (prev->ds_ctx)
ds_prev = (unsigned long)prev->ds_ctx->ds;
if (next->ds_ctx)
ds_next = (unsigned long)next->ds_ctx->ds;
if (ds_next != ds_prev) {
/*
* We clear debugctl to make sure DS
* is not in use when we change it:
*/
debugctl = 0;
update_debugctlmsr(0);
wrmsrl(MSR_IA32_DS_AREA, ds_next);
}
}
#endif /* CONFIG_X86_DS */
if (next->debugctlmsr != debugctl)
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(next_p, TIF_DEBUG)) {
@ -534,14 +516,6 @@ static inline void __switch_to_xtra(struct task_struct *prev_p,
*/
memset(tss->io_bitmap, 0xff, prev->io_bitmap_max);
}
#ifdef CONFIG_X86_PTRACE_BTS
if (test_tsk_thread_flag(prev_p, TIF_BTS_TRACE_TS))
ptrace_bts_take_timestamp(prev_p, BTS_TASK_DEPARTS);
if (test_tsk_thread_flag(next_p, TIF_BTS_TRACE_TS))
ptrace_bts_take_timestamp(next_p, BTS_TASK_ARRIVES);
#endif /* CONFIG_X86_PTRACE_BTS */
}
/*

434
arch/x86/kernel/ptrace.c
View File

@ -581,153 +581,73 @@ static int ioperm_get(struct task_struct *target,
}
#ifdef CONFIG_X86_PTRACE_BTS
/*
* The configuration for a particular BTS hardware implementation.
*/
struct bts_configuration {
/* the size of a BTS record in bytes; at most BTS_MAX_RECORD_SIZE */
unsigned char sizeof_bts;
/* the size of a field in the BTS record in bytes */
unsigned char sizeof_field;
/* a bitmask to enable/disable BTS in DEBUGCTL MSR */
unsigned long debugctl_mask;
};
static struct bts_configuration bts_cfg;
#define BTS_MAX_RECORD_SIZE (8 * 3)
/*
* 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 first 8 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.
*/
enum bts_field {
bts_from = 0,
bts_to,
bts_flags,
bts_escape = (unsigned long)-1,
bts_qual = bts_to,
bts_jiffies = bts_flags
};
static inline unsigned long bts_get(const char *base, enum bts_field field)
{
base += (bts_cfg.sizeof_field * field);
return *(unsigned long *)base;
}
static inline void bts_set(char *base, enum bts_field field, unsigned long val)
{
base += (bts_cfg.sizeof_field * field);;
(*(unsigned long *)base) = val;
}
/*
* Translate a BTS record from the raw format into the bts_struct format
*
* out (out): bts_struct interpretation
* raw: raw BTS record
*/
static void ptrace_bts_translate_record(struct bts_struct *out, const void *raw)
{
memset(out, 0, sizeof(*out));
if (bts_get(raw, bts_from) == bts_escape) {
out->qualifier = bts_get(raw, bts_qual);
out->variant.jiffies = bts_get(raw, bts_jiffies);
} else {
out->qualifier = BTS_BRANCH;
out->variant.lbr.from_ip = bts_get(raw, bts_from);
out->variant.lbr.to_ip = bts_get(raw, bts_to);
}
}
static int ptrace_bts_read_record(struct task_struct *child, size_t index,
struct bts_struct __user *out)
{
struct bts_struct ret;
const void *bts_record;
size_t bts_index, bts_end;
const struct bts_trace *trace;
struct bts_struct bts;
const unsigned char *at;
int error;
error = ds_get_bts_end(child->bts, &bts_end);
trace = ds_read_bts(child->bts);
if (!trace)
return -EPERM;
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(child->bts, at, &bts);
if (error < 0)
return error;
if (bts_end <= index)
return -EINVAL;
error = ds_get_bts_index(child->bts, &bts_index);
if (error < 0)
return error;
/* translate the ptrace bts index into the ds bts index */
bts_index += bts_end - (index + 1);
if (bts_end <= bts_index)
bts_index -= bts_end;
error = ds_access_bts(child->bts, bts_index, &bts_record);
if (error < 0)
return error;
ptrace_bts_translate_record(&ret, bts_record);
if (copy_to_user(out, &ret, sizeof(ret)))
if (copy_to_user(out, &bts, sizeof(bts)))
return -EFAULT;
return sizeof(ret);
return sizeof(bts);
}
static int ptrace_bts_drain(struct task_struct *child,
long size,
struct bts_struct __user *out)
{
struct bts_struct ret;
const unsigned char *raw;
size_t end, i;
int error;
const struct bts_trace *trace;
const unsigned char *at;
int error, drained = 0;
error = ds_get_bts_index(child->bts, &end);
if (error < 0)
return error;
trace = ds_read_bts(child->bts);
if (!trace)
return -EPERM;
if (size < (end * sizeof(struct bts_struct)))
if (!trace->read)
return -EOPNOTSUPP;
if (size < (trace->ds.top - trace->ds.begin))
return -EIO;
error = ds_access_bts(child->bts, 0, (const void **)&raw);
if (error < 0)
return error;
for (at = trace->ds.begin; (void *)at < trace->ds.top;
out++, drained++, at += trace->ds.size) {
struct bts_struct bts;
int error;
for (i = 0; i < end; i++, out++, raw += bts_cfg.sizeof_bts) {
ptrace_bts_translate_record(&ret, raw);
error = trace->read(child->bts, at, &bts);
if (error < 0)
return error;
if (copy_to_user(out, &ret, sizeof(ret)))
if (copy_to_user(out, &bts, sizeof(bts)))
return -EFAULT;
}
error = ds_clear_bts(child->bts);
memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size);
error = ds_reset_bts(child->bts);
if (error < 0)
return error;
return end;
return drained;
}
static int ptrace_bts_config(struct task_struct *child,
@ -735,136 +655,89 @@ static int ptrace_bts_config(struct task_struct *child,
const struct ptrace_bts_config __user *ucfg)
{
struct ptrace_bts_config cfg;
int error = 0;
unsigned int flags = 0;
error = -EOPNOTSUPP;
if (!bts_cfg.sizeof_bts)
goto errout;
error = -EIO;
if (cfg_size < sizeof(cfg))
goto errout;
return -EIO;
error = -EFAULT;
if (copy_from_user(&cfg, ucfg, sizeof(cfg)))
goto errout;
return -EFAULT;
error = -EINVAL;
if ((cfg.flags & PTRACE_BTS_O_SIGNAL) &&
!(cfg.flags & PTRACE_BTS_O_ALLOC))
goto errout;
if (cfg.flags & PTRACE_BTS_O_ALLOC) {
bts_ovfl_callback_t ovfl = NULL;
unsigned int sig = 0;
error = -EINVAL;
if (cfg.size < (10 * bts_cfg.sizeof_bts))
goto errout;
if (cfg.flags & PTRACE_BTS_O_SIGNAL) {
if (!cfg.signal)
goto errout;
error = -EOPNOTSUPP;
goto errout;
sig = cfg.signal;
}
if (child->bts) {
(void)ds_release_bts(child->bts);
kfree(child->bts_buffer);
child->bts = NULL;
child->bts_buffer = NULL;
}
error = -ENOMEM;
child->bts_buffer = kzalloc(cfg.size, GFP_KERNEL);
if (!child->bts_buffer)
goto errout;
child->bts = ds_request_bts(child, child->bts_buffer, cfg.size,
ovfl, /* th = */ (size_t)-1);
if (IS_ERR(child->bts)) {
error = PTR_ERR(child->bts);
kfree(child->bts_buffer);
child->bts = NULL;
child->bts_buffer = NULL;
goto errout;
}
child->thread.bts_ovfl_signal = sig;
if (child->bts) {
ds_release_bts(child->bts);
child->bts = NULL;
}
error = -EINVAL;
if (!child->thread.ds_ctx && cfg.flags)
goto errout;
if (cfg.flags & PTRACE_BTS_O_SIGNAL) {
if (!cfg.signal)
return -EINVAL;
return -EOPNOTSUPP;
child->thread.bts_ovfl_signal = cfg.signal;
}
if ((cfg.flags & PTRACE_BTS_O_ALLOC) &&
(cfg.size != child->bts_size)) {
kfree(child->bts_buffer);
child->bts_size = cfg.size;
child->bts_buffer = kzalloc(cfg.size, GFP_KERNEL);
if (!child->bts_buffer) {
child->bts_size = 0;
return -ENOMEM;
}
}
if (cfg.flags & PTRACE_BTS_O_TRACE)
child->thread.debugctlmsr |= bts_cfg.debugctl_mask;
else
child->thread.debugctlmsr &= ~bts_cfg.debugctl_mask;
flags |= BTS_USER;
if (cfg.flags & PTRACE_BTS_O_SCHED)
set_tsk_thread_flag(child, TIF_BTS_TRACE_TS);
else
clear_tsk_thread_flag(child, TIF_BTS_TRACE_TS);
flags |= BTS_TIMESTAMPS;
error = sizeof(cfg);
child->bts = ds_request_bts(child, child->bts_buffer, child->bts_size,
/* ovfl = */ NULL, /* th = */ (size_t)-1,
flags);
if (IS_ERR(child->bts)) {
int error = PTR_ERR(child->bts);
out:
if (child->thread.debugctlmsr)
set_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
else
clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
kfree(child->bts_buffer);
child->bts = NULL;
child->bts_buffer = NULL;
child->bts_size = 0;
return error;
return error;
}
errout:
child->thread.debugctlmsr &= ~bts_cfg.debugctl_mask;
clear_tsk_thread_flag(child, TIF_BTS_TRACE_TS);
goto out;
return sizeof(cfg);
}
static int ptrace_bts_status(struct task_struct *child,
long cfg_size,
struct ptrace_bts_config __user *ucfg)
{
const struct bts_trace *trace;
struct ptrace_bts_config cfg;
size_t end;
const void *base, *max;
int error;
if (cfg_size < sizeof(cfg))
return -EIO;
error = ds_get_bts_end(child->bts, &end);
if (error < 0)
return error;
error = ds_access_bts(child->bts, /* index = */ 0, &base);
if (error < 0)
return error;
error = ds_access_bts(child->bts, /* index = */ end, &max);
if (error < 0)
return error;
trace = ds_read_bts(child->bts);
if (!trace)
return -EPERM;
memset(&cfg, 0, sizeof(cfg));
cfg.size = (max - base);
cfg.size = trace->ds.end - trace->ds.begin;
cfg.signal = child->thread.bts_ovfl_signal;
cfg.bts_size = sizeof(struct bts_struct);
if (cfg.signal)
cfg.flags |= PTRACE_BTS_O_SIGNAL;
if (test_tsk_thread_flag(child, TIF_DEBUGCTLMSR) &&
child->thread.debugctlmsr & bts_cfg.debugctl_mask)
if (trace->ds.flags & BTS_USER)
cfg.flags |= PTRACE_BTS_O_TRACE;
if (test_tsk_thread_flag(child, TIF_BTS_TRACE_TS))
if (trace->ds.flags & BTS_TIMESTAMPS)
cfg.flags |= PTRACE_BTS_O_SCHED;
if (copy_to_user(ucfg, &cfg, sizeof(cfg)))
@ -873,105 +746,28 @@ static int ptrace_bts_status(struct task_struct *child,
return sizeof(cfg);
}
static int ptrace_bts_write_record(struct task_struct *child,
const struct bts_struct *in)
static int ptrace_bts_clear(struct task_struct *child)
{
unsigned char bts_record[BTS_MAX_RECORD_SIZE];
const struct bts_trace *trace;
if (BTS_MAX_RECORD_SIZE < bts_cfg.sizeof_bts)
return -EOVERFLOW;
trace = ds_read_bts(child->bts);
if (!trace)
return -EPERM;
memset(bts_record, 0, bts_cfg.sizeof_bts);
switch (in->qualifier) {
case BTS_INVALID:
break;
memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size);
case BTS_BRANCH:
bts_set(bts_record, bts_from, in->variant.lbr.from_ip);
bts_set(bts_record, bts_to, in->variant.lbr.to_ip);
break;
case BTS_TASK_ARRIVES:
case BTS_TASK_DEPARTS:
bts_set(bts_record, bts_from, bts_escape);
bts_set(bts_record, bts_qual, in->qualifier);
bts_set(bts_record, bts_jiffies, in->variant.jiffies);
break;
default:
return -EINVAL;
}
return ds_write_bts(child->bts, bts_record, bts_cfg.sizeof_bts);
return ds_reset_bts(child->bts);
}
void ptrace_bts_take_timestamp(struct task_struct *tsk,
enum bts_qualifier qualifier)
static int ptrace_bts_size(struct task_struct *child)
{
struct bts_struct rec = {
.qualifier = qualifier,
.variant.jiffies = jiffies_64
};
const struct bts_trace *trace;
ptrace_bts_write_record(tsk, &rec);
}
trace = ds_read_bts(child->bts);
if (!trace)
return -EPERM;
static const struct bts_configuration bts_cfg_netburst = {
.sizeof_bts = sizeof(long) * 3,
.sizeof_field = sizeof(long),
.debugctl_mask = (1<<2)|(1<<3)|(1<<5)
};
static const struct bts_configuration bts_cfg_pentium_m = {
.sizeof_bts = sizeof(long) * 3,
.sizeof_field = sizeof(long),
.debugctl_mask = (1<<6)|(1<<7)
};
static const struct bts_configuration bts_cfg_core2 = {
.sizeof_bts = 8 * 3,
.sizeof_field = 8,
.debugctl_mask = (1<<6)|(1<<7)|(1<<9)
};
static inline void bts_configure(const struct bts_configuration *cfg)
{
bts_cfg = *cfg;
}
void __cpuinit ptrace_bts_init_intel(struct cpuinfo_x86 *c)
{
switch (c->x86) {
case 0x6:
switch (c->x86_model) {
case 0 ... 0xC:
/* sorry, don't know about them */
break;
case 0xD:
case 0xE: /* Pentium M */
bts_configure(&bts_cfg_pentium_m);
break;
default: /* Core2, Atom, ... */
bts_configure(&bts_cfg_core2);
break;
}
break;
case 0xF:
switch (c->x86_model) {
case 0x0:
case 0x1:
case 0x2: /* Netburst */
bts_configure(&bts_cfg_netburst);
break;
default:
/* sorry, don't know about them */
break;
}
break;
default:
/* sorry, don't know about them */
break;
}
return (trace->ds.top - trace->ds.begin) / trace->ds.size;
}
#endif /* CONFIG_X86_PTRACE_BTS */
@ -988,15 +784,12 @@ void ptrace_disable(struct task_struct *child)
#endif
#ifdef CONFIG_X86_PTRACE_BTS
if (child->bts) {
(void)ds_release_bts(child->bts);
ds_release_bts(child->bts);
child->bts = NULL;
kfree(child->bts_buffer);
child->bts_buffer = NULL;
child->thread.debugctlmsr &= ~bts_cfg.debugctl_mask;
if (!child->thread.debugctlmsr)
clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
clear_tsk_thread_flag(child, TIF_BTS_TRACE_TS);
child->bts_size = 0;
}
#endif /* CONFIG_X86_PTRACE_BTS */
}
@ -1129,16 +922,9 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
(child, data, (struct ptrace_bts_config __user *)addr);
break;
case PTRACE_BTS_SIZE: {
size_t size;
ret = ds_get_bts_index(child->bts, &size);
if (ret == 0) {
WARN_ON_ONCE(size != (int) size);
ret = (int) size;
}
case PTRACE_BTS_SIZE:
ret = ptrace_bts_size(child);
break;
}
case PTRACE_BTS_GET:
ret = ptrace_bts_read_record
@ -1146,7 +932,7 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
break;
case PTRACE_BTS_CLEAR:
ret = ds_clear_bts(child->bts);
ret = ptrace_bts_clear(child);
break;
case PTRACE_BTS_DRAIN:
@ -1409,6 +1195,14 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
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:

1
include/linux/sched.h
View File

@ -1176,6 +1176,7 @@ struct task_struct {
* The buffer to hold the BTS data.
*/
void *bts_buffer;
size_t bts_size;
#endif /* CONFIG_X86_PTRACE_BTS */
/* PID/PID hash table linkage. */