x86, ptrace: new ptrace BTS API (a95d67f8) · Commits · 戴 / test

arch/x86/kernel/ds.c

+51 −5

Original line number	Diff line number	Diff line
		@@ -177,18 +177,20 @@ static inline void set_info_data(char *base, unsigned long value)
		}


		int ds_allocate(void **dsp, size_t bts_size_in_records)
		int ds_allocate(void **dsp, size_t bts_size_in_bytes)
		{
		size_t bts_size_in_bytes = 0;
		void *bts = 0;
		void *ds = 0;
		size_t bts_size_in_records;
		void *bts;
		void *ds;

		if (!ds_cfg.sizeof_ds \|\| !ds_cfg.sizeof_bts)
		return -EOPNOTSUPP;

		if (bts_size_in_records < 0)
		if (bts_size_in_bytes < 0)
		return -EINVAL;

		bts_size_in_records =
		bts_size_in_bytes / ds_cfg.sizeof_bts;
		bts_size_in_bytes =
		bts_size_in_records * ds_cfg.sizeof_bts;

		@@ -233,9 +235,21 @@ int ds_get_bts_size(void *ds)
		if (!ds_cfg.sizeof_ds \|\| !ds_cfg.sizeof_bts)
		return -EOPNOTSUPP;

		if (!ds)
		return 0;

		size_in_bytes =
		get_bts_absolute_maximum(ds) -
		get_bts_buffer_base(ds);
		return size_in_bytes;
		}

		int ds_get_bts_end(void *ds)
		{
		size_t size_in_bytes = ds_get_bts_size(ds);

		if (size_in_bytes <= 0)
		return size_in_bytes;

		return size_in_bytes / ds_cfg.sizeof_bts;
		}
		@@ -254,6 +268,38 @@ int ds_get_bts_index(void *ds)
		return index_offset_in_bytes / ds_cfg.sizeof_bts;
		}

		int ds_set_overflow(void *ds, int method)
		{
		switch (method) {
		case DS_O_SIGNAL:
		return -EOPNOTSUPP;
		case DS_O_WRAP:
		return 0;
		default:
		return -EINVAL;
		}
		}

		int ds_get_overflow(void *ds)
		{
		return DS_O_WRAP;
		}

		int ds_clear(void *ds)
		{
		int bts_size = ds_get_bts_size(ds);
		void *bts_base;

		if (bts_size <= 0)
		return bts_size;

		bts_base = get_bts_buffer_base(ds);
		memset(bts_base, 0, bts_size);

		set_bts_index(ds, bts_base);
		return 0;
		}

		int ds_read_bts(void ds, size_t index, struct bts_struct out)
		{
		void *bts;

arch/x86/kernel/ptrace.c

+130 −91

Original line number	Diff line number	Diff line
		@@ -32,12 +32,6 @@
		#include <asm/ds.h>


		/*
		* The maximal size of a BTS buffer per traced task in number of BTS
		* records.
		*/
		#define PTRACE_BTS_BUFFER_MAX 4000

		/*
		* does not yet catch signals sent when the child dies.
		* in exit.c or in signal.c.
		@@ -466,17 +460,12 @@ static int ptrace_set_debugreg(struct task_struct *child,
		return 0;
		}

		static int ptrace_bts_max_buffer_size(void)
		{
		return PTRACE_BTS_BUFFER_MAX;
		}

		static int ptrace_bts_get_buffer_size(struct task_struct *child)
		static int ptrace_bts_get_size(struct task_struct *child)
		{
		if (!child->thread.ds_area_msr)
		return -ENXIO;

		return ds_get_bts_size((void *)child->thread.ds_area_msr);
		return ds_get_bts_index((void *)child->thread.ds_area_msr);
		}

		static int ptrace_bts_read_record(struct task_struct *child,
		@@ -485,7 +474,7 @@ static int ptrace_bts_read_record(struct task_struct *child,
		{
		struct bts_struct ret;
		int retval;
		int bts_size;
		int bts_end;
		int bts_index;

		if (!child->thread.ds_area_msr)
		@@ -494,15 +483,15 @@ static int ptrace_bts_read_record(struct task_struct *child,
		if (index < 0)
		return -EINVAL;

		bts_size = ds_get_bts_size((void *)child->thread.ds_area_msr);
		if (bts_size <= index)
		bts_end = ds_get_bts_end((void *)child->thread.ds_area_msr);
		if (bts_end <= index)
		return -EINVAL;

		/* translate the ptrace bts index into the ds bts index */
		bts_index = ds_get_bts_index((void *)child->thread.ds_area_msr);
		bts_index -= (index + 1);
		if (bts_index < 0)
		bts_index += bts_size;
		bts_index += bts_end;

		retval = ds_read_bts((void *)child->thread.ds_area_msr,
		bts_index, &ret);
		@@ -530,19 +519,97 @@ static int ptrace_bts_write_record(struct task_struct *child,
		return sizeof(*in);
		}

		static int ptrace_bts_config(struct task_struct *child,
		unsigned long options)
		static int ptrace_bts_clear(struct task_struct *child)
		{
		if (!child->thread.ds_area_msr)
		return -ENXIO;

		return ds_clear((void *)child->thread.ds_area_msr);
		}

		static int ptrace_bts_drain(struct task_struct *child,
		struct bts_struct __user *out)
		{
		unsigned long debugctl_mask = ds_debugctl_mask();
		int end, i;
		void ds = (void )child->thread.ds_area_msr;

		if (!ds)
		return -ENXIO;

		end = ds_get_bts_index(ds);
		if (end <= 0)
		return end;

		for (i = 0; i < end; i++, out++) {
		struct bts_struct ret;
		int retval;

		retval = ptrace_bts_get_buffer_size(child);
		retval = ds_read_bts(ds, i, &ret);
		if (retval < 0)
		return retval;
		if (retval == 0)
		return -ENXIO;

		if (options & PTRACE_BTS_O_TRACE_TASK) {
		if (copy_to_user(out, &ret, sizeof(ret)))
		return -EFAULT;
		}

		ds_clear(ds);

		return i;
		}

		static int ptrace_bts_config(struct task_struct *child,
		const struct ptrace_bts_config __user *ucfg)
		{
		struct ptrace_bts_config cfg;
		unsigned long debugctl_mask;
		int bts_size, ret;
		void *ds;

		if (copy_from_user(&cfg, ucfg, sizeof(cfg)))
		return -EFAULT;

		bts_size = 0;
		ds = (void *)child->thread.ds_area_msr;
		if (ds) {
		bts_size = ds_get_bts_size(ds);
		if (bts_size < 0)
		return bts_size;
		}

		if (bts_size != cfg.size) {
		ret = ds_free((void **)&child->thread.ds_area_msr);
		if (ret < 0)
		return ret;

		if (cfg.size > 0)
		ret = ds_allocate((void **)&child->thread.ds_area_msr,
		cfg.size);
		ds = (void *)child->thread.ds_area_msr;
		if (ds)
		set_tsk_thread_flag(child, TIF_DS_AREA_MSR);
		else
		clear_tsk_thread_flag(child, TIF_DS_AREA_MSR);

		if (ret < 0)
		return ret;

		bts_size = ds_get_bts_size(ds);
		if (bts_size <= 0)
		return bts_size;
		}

		if (ds) {
		if (cfg.flags & PTRACE_BTS_O_SIGNAL) {
		ret = ds_set_overflow(ds, DS_O_SIGNAL);
		} else {
		ret = ds_set_overflow(ds, DS_O_WRAP);
		}
		if (ret < 0)
		return ret;
		}

		debugctl_mask = ds_debugctl_mask();
		if (ds && (cfg.flags & PTRACE_BTS_O_TRACE)) {
		child->thread.debugctlmsr \|= debugctl_mask;
		set_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
		} else {
		@@ -555,7 +622,7 @@ static int ptrace_bts_config(struct task_struct *child,
		clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
		}

		if (options & PTRACE_BTS_O_TIMESTAMPS)
		if (ds && (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);
		@@ -563,59 +630,32 @@ static int ptrace_bts_config(struct task_struct *child,
		return 0;
		}

		static int ptrace_bts_status(struct task_struct *child)
		static int ptrace_bts_status(struct task_struct *child,
		struct ptrace_bts_config __user *ucfg)
		{
		unsigned long debugctl_mask = ds_debugctl_mask();
		int retval, status = 0;
		void ds = (void )child->thread.ds_area_msr;
		struct ptrace_bts_config cfg;

		retval = ptrace_bts_get_buffer_size(child);
		if (retval < 0)
		return retval;
		if (retval == 0)
		return -ENXIO;

		if (ptrace_bts_get_buffer_size(child) <= 0)
		return -ENXIO;

		if (test_tsk_thread_flag(child, TIF_DEBUGCTLMSR) &&
		child->thread.debugctlmsr & debugctl_mask)
		status \|= PTRACE_BTS_O_TRACE_TASK;
		if (test_tsk_thread_flag(child, TIF_BTS_TRACE_TS))
		status \|= PTRACE_BTS_O_TIMESTAMPS;
		memset(&cfg, 0, sizeof(cfg));

		return status;
		}

		static int ptrace_bts_allocate_bts(struct task_struct *child,
		int size_in_records)
		{
		int retval = 0;
		void *ds;
		if (ds) {
		cfg.size = ds_get_bts_size(ds);

		if (size_in_records < 0)
		return -EINVAL;
		if (ds_get_overflow(ds) == DS_O_SIGNAL)
		cfg.flags \|= PTRACE_BTS_O_SIGNAL;

		if (size_in_records > ptrace_bts_max_buffer_size())
		return -EINVAL;
		if (test_tsk_thread_flag(child, TIF_DEBUGCTLMSR) &&
		child->thread.debugctlmsr & ds_debugctl_mask())
		cfg.flags \|= PTRACE_BTS_O_TRACE;

		if (size_in_records == 0) {
		ptrace_bts_config(child, /* options = */ 0);
		} else {
		retval = ds_allocate(&ds, size_in_records);
		if (retval)
		return retval;
		if (test_tsk_thread_flag(child, TIF_BTS_TRACE_TS))
		cfg.flags \|= PTRACE_BTS_O_SCHED;
		}

		if (child->thread.ds_area_msr)
		ds_free((void **)&child->thread.ds_area_msr);

		child->thread.ds_area_msr = (unsigned long)ds;
		if (child->thread.ds_area_msr)
		set_tsk_thread_flag(child, TIF_DS_AREA_MSR);
		else
		clear_tsk_thread_flag(child, TIF_DS_AREA_MSR);
		if (copy_to_user(ucfg, &cfg, sizeof(cfg)))
		return -EFAULT;

		return retval;
		return sizeof(cfg);
		}

		void ptrace_bts_take_timestamp(struct task_struct *tsk,
		@@ -626,9 +666,6 @@ void ptrace_bts_take_timestamp(struct task_struct *tsk,
		.variant.jiffies = jiffies
		};

		if (ptrace_bts_get_buffer_size(tsk) <= 0)
		return;

		ptrace_bts_write_record(tsk, &rec);
		}

		@@ -808,30 +845,32 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
		break;
		#endif

		case PTRACE_BTS_MAX_BUFFER_SIZE:
		ret = ptrace_bts_max_buffer_size();
		case PTRACE_BTS_CONFIG:
		ret = ptrace_bts_config
		(child, (struct ptrace_bts_config __user *)addr);
		break;

		case PTRACE_BTS_ALLOCATE_BUFFER:
		ret = ptrace_bts_allocate_bts(child, data);
		case PTRACE_BTS_STATUS:
		ret = ptrace_bts_status
		(child, (struct ptrace_bts_config __user *)addr);
		break;

		case PTRACE_BTS_GET_BUFFER_SIZE:
		ret = ptrace_bts_get_buffer_size(child);
		case PTRACE_BTS_SIZE:
		ret = ptrace_bts_get_size(child);
		break;

		case PTRACE_BTS_READ_RECORD:
		case PTRACE_BTS_GET:
		ret = ptrace_bts_read_record
		(child, data,
		(struct bts_struct __user *) addr);
		(child, data, (struct bts_struct __user *) addr);
		break;

		case PTRACE_BTS_CONFIG:
		ret = ptrace_bts_config(child, data);
		case PTRACE_BTS_CLEAR:
		ret = ptrace_bts_clear(child);
		break;

		case PTRACE_BTS_STATUS:
		ret = ptrace_bts_status(child);
		case PTRACE_BTS_DRAIN:
		ret = ptrace_bts_drain
		(child, (struct bts_struct __user *) addr);
		break;

		default:
		@@ -1017,12 +1056,12 @@ asmlinkage long sys32_ptrace(long request, u32 pid, u32 addr, u32 data)
		case PTRACE_SETOPTIONS:
		case PTRACE_SET_THREAD_AREA:
		case PTRACE_GET_THREAD_AREA:
		case PTRACE_BTS_MAX_BUFFER_SIZE:
		case PTRACE_BTS_ALLOCATE_BUFFER:
		case PTRACE_BTS_GET_BUFFER_SIZE:
		case PTRACE_BTS_READ_RECORD:
		case PTRACE_BTS_CONFIG:
		case PTRACE_BTS_STATUS:
		case PTRACE_BTS_SIZE:
		case PTRACE_BTS_GET:
		case PTRACE_BTS_CLEAR:
		case PTRACE_BTS_DRAIN:
		return sys_ptrace(request, pid, addr, data);

		default:

include/asm-x86/ds.h

+7 −0

Original line number	Diff line number	Diff line
		@@ -52,11 +52,18 @@ struct bts_struct {
		} variant;
		};

		/* Overflow handling mechanisms */
		#define DS_O_SIGNAL 1 /* send overflow signal */
		#define DS_O_WRAP 2 /* wrap around */

		extern int ds_allocate(void **, size_t);
		extern int ds_free(void **);
		extern int ds_get_bts_size(void *);
		extern int ds_get_bts_end(void *);
		extern int ds_get_bts_index(void *);
		extern int ds_set_overflow(void *, int);
		extern int ds_get_overflow(void *);
		extern int ds_clear(void *);
		extern int ds_read_bts(void , size_t, struct bts_struct );
		extern int ds_write_bts(void , const struct bts_struct );
		extern unsigned long ds_debugctl_mask(void);

include/asm-x86/ptrace-abi.h

+48 −46

Original line number	Diff line number	Diff line
		@@ -80,51 +80,53 @@

		#define PTRACE_SINGLEBLOCK 33 /* resume execution until next branch */

		/* Return maximal BTS buffer size in number of records,
		if successuf; -1, otherwise.
		EOPNOTSUPP...processor does not support bts tracing */
		#define PTRACE_BTS_MAX_BUFFER_SIZE 40

		/* Allocate new bts buffer (free old one, if exists) of size DATA bts records;
		parameter ADDR is ignored.
		Return 0, if successful; -1, otherwise.
		EOPNOTSUPP...processor does not support bts tracing
		EINVAL.......invalid size in records
		ENOMEM.......out of memory */
		#define PTRACE_BTS_ALLOCATE_BUFFER 41

		/* Return the size of the bts buffer in number of bts records,
		if successful; -1, otherwise.
		EOPNOTSUPP...processor does not support bts tracing
		ENXIO........no buffer allocated */
		#define PTRACE_BTS_GET_BUFFER_SIZE 42

		/* Read the DATA'th bts record into a ptrace_bts_record buffer
		provided in ADDR.
		Records are ordered from newest to oldest.
		Return 0, if successful; -1, otherwise
		EOPNOTSUPP...processor does not support bts tracing
		ENXIO........no buffer allocated
		EINVAL.......invalid index */
		#define PTRACE_BTS_READ_RECORD 43

		/* Configure last branch trace; the configuration is given as a bit-mask of
		PTRACE_BTS_O_* options in DATA; parameter ADDR is ignored.
		Return 0, if successful; -1, otherwise
		EOPNOTSUPP...processor does not support bts tracing
		ENXIO........no buffer allocated */
		#define PTRACE_BTS_CONFIG 44

		/* Return the configuration as bit-mask of PTRACE_BTS_O_* options
		if successful; -1, otherwise.
		EOPNOTSUPP...processor does not support bts tracing
		ENXIO........no buffer allocated */
		#define PTRACE_BTS_STATUS 45

		/* Trace configuration options */
		/* Collect last branch trace */
		#define PTRACE_BTS_O_TRACE_TASK 0x1
		/* Take timestamps when the task arrives and departs */
		#define PTRACE_BTS_O_TIMESTAMPS 0x2
		/* 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 */
		unsigned long size;
		/* bitmask of below flags */
		unsigned long flags;
		};

		#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? on buffer overflow
		instead of wrapping around */
		#define PTRACE_BTS_O_CUT_SIZE 0x8 /* cut requested size to max available
		instead of failing */

		#define PTRACE_BTS_CONFIG 40
		/* Configure branch trace recording.
		DATA is ignored, ADDR points to a struct ptrace_bts_config.
		A new buffer is allocated, iff the size changes.
		*/
		#define PTRACE_BTS_STATUS 41
		/* Return the current configuration.
		DATA is ignored, ADDR points to a struct ptrace_bts_config
		that will contain the result.
		*/
		#define PTRACE_BTS_SIZE 42
		/* Return the number of available BTS records.
		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.
		DATA is ignored. ADDR points to an array of struct bts_struct of
		suitable size.
		BTS records are read from oldest to newest.
		Returns number of BTS records drained.
		*/

		#endif

include/asm-x86/ptrace.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -9,6 +9,7 @@

		#ifdef __KERNEL__

		/* the DS BTS struct is used for ptrace as well */
		#include <asm/ds.h>

		struct task_struct;

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