x86, bts: provide in-kernel branch-trace interface
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
committed by
Ingo Molnar
Ingo Molnar
parent
b0884e25fe
commit
c2724775ce
@@ -581,153 +581,73 @@ static int ioperm_get(struct task_struct *target,
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}
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#ifdef CONFIG_X86_PTRACE_BTS
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/*
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* The configuration for a particular BTS hardware implementation.
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*/
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struct bts_configuration {
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/* the size of a BTS record in bytes; at most BTS_MAX_RECORD_SIZE */
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unsigned char sizeof_bts;
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/* the size of a field in the BTS record in bytes */
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unsigned char sizeof_field;
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/* a bitmask to enable/disable BTS in DEBUGCTL MSR */
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unsigned long debugctl_mask;
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};
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static struct bts_configuration bts_cfg;
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#define BTS_MAX_RECORD_SIZE (8 * 3)
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/*
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* Branch Trace Store (BTS) uses the following format. Different
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* architectures vary in the size of those fields.
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* - source linear address
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* - destination linear address
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* - flags
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*
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* Later architectures use 64bit pointers throughout, whereas earlier
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* architectures use 32bit pointers in 32bit mode.
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*
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* We compute the base address for the first 8 fields based on:
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* - the field size stored in the DS configuration
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* - the relative field position
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*
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* In order to store additional information in the BTS buffer, we use
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* a special source address to indicate that the record requires
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* special interpretation.
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*
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* Netburst indicated via a bit in the flags field whether the branch
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* was predicted; this is ignored.
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*/
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enum bts_field {
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bts_from = 0,
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bts_to,
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bts_flags,
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bts_escape = (unsigned long)-1,
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bts_qual = bts_to,
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bts_jiffies = bts_flags
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};
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static inline unsigned long bts_get(const char *base, enum bts_field field)
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{
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base += (bts_cfg.sizeof_field * field);
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return *(unsigned long *)base;
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}
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static inline void bts_set(char *base, enum bts_field field, unsigned long val)
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{
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base += (bts_cfg.sizeof_field * field);;
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(*(unsigned long *)base) = val;
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}
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/*
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* Translate a BTS record from the raw format into the bts_struct format
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*
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* out (out): bts_struct interpretation
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* raw: raw BTS record
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*/
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static void ptrace_bts_translate_record(struct bts_struct *out, const void *raw)
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{
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memset(out, 0, sizeof(*out));
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if (bts_get(raw, bts_from) == bts_escape) {
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out->qualifier = bts_get(raw, bts_qual);
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out->variant.jiffies = bts_get(raw, bts_jiffies);
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} else {
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out->qualifier = BTS_BRANCH;
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out->variant.lbr.from_ip = bts_get(raw, bts_from);
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out->variant.lbr.to_ip = bts_get(raw, bts_to);
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}
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}
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static int ptrace_bts_read_record(struct task_struct *child, size_t index,
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struct bts_struct __user *out)
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{
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struct bts_struct ret;
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const void *bts_record;
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size_t bts_index, bts_end;
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const struct bts_trace *trace;
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struct bts_struct bts;
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const unsigned char *at;
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int error;
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error = ds_get_bts_end(child->bts, &bts_end);
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trace = ds_read_bts(child->bts);
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if (!trace)
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return -EPERM;
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at = trace->ds.top - ((index + 1) * trace->ds.size);
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if ((void *)at < trace->ds.begin)
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at += (trace->ds.n * trace->ds.size);
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if (!trace->read)
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return -EOPNOTSUPP;
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error = trace->read(child->bts, at, &bts);
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if (error < 0)
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return error;
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if (bts_end <= index)
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return -EINVAL;
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error = ds_get_bts_index(child->bts, &bts_index);
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if (error < 0)
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return error;
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/* translate the ptrace bts index into the ds bts index */
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bts_index += bts_end - (index + 1);
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if (bts_end <= bts_index)
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bts_index -= bts_end;
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error = ds_access_bts(child->bts, bts_index, &bts_record);
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if (error < 0)
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return error;
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ptrace_bts_translate_record(&ret, bts_record);
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if (copy_to_user(out, &ret, sizeof(ret)))
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if (copy_to_user(out, &bts, sizeof(bts)))
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return -EFAULT;
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return sizeof(ret);
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return sizeof(bts);
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}
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static int ptrace_bts_drain(struct task_struct *child,
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long size,
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struct bts_struct __user *out)
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{
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struct bts_struct ret;
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const unsigned char *raw;
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size_t end, i;
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int error;
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const struct bts_trace *trace;
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const unsigned char *at;
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int error, drained = 0;
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error = ds_get_bts_index(child->bts, &end);
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if (error < 0)
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return error;
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trace = ds_read_bts(child->bts);
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if (!trace)
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return -EPERM;
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if (size < (end * sizeof(struct bts_struct)))
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if (!trace->read)
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return -EOPNOTSUPP;
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if (size < (trace->ds.top - trace->ds.begin))
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return -EIO;
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error = ds_access_bts(child->bts, 0, (const void **)&raw);
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if (error < 0)
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return error;
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for (at = trace->ds.begin; (void *)at < trace->ds.top;
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out++, drained++, at += trace->ds.size) {
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struct bts_struct bts;
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int error;
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for (i = 0; i < end; i++, out++, raw += bts_cfg.sizeof_bts) {
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ptrace_bts_translate_record(&ret, raw);
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error = trace->read(child->bts, at, &bts);
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if (error < 0)
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return error;
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if (copy_to_user(out, &ret, sizeof(ret)))
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if (copy_to_user(out, &bts, sizeof(bts)))
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return -EFAULT;
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}
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error = ds_clear_bts(child->bts);
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memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size);
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error = ds_reset_bts(child->bts);
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if (error < 0)
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return error;
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return end;
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return drained;
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}
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static int ptrace_bts_config(struct task_struct *child,
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@@ -735,136 +655,89 @@ static int ptrace_bts_config(struct task_struct *child,
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const struct ptrace_bts_config __user *ucfg)
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{
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struct ptrace_bts_config cfg;
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int error = 0;
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unsigned int flags = 0;
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error = -EOPNOTSUPP;
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if (!bts_cfg.sizeof_bts)
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goto errout;
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error = -EIO;
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if (cfg_size < sizeof(cfg))
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goto errout;
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return -EIO;
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error = -EFAULT;
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if (copy_from_user(&cfg, ucfg, sizeof(cfg)))
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goto errout;
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return -EFAULT;
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error = -EINVAL;
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if ((cfg.flags & PTRACE_BTS_O_SIGNAL) &&
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!(cfg.flags & PTRACE_BTS_O_ALLOC))
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goto errout;
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if (cfg.flags & PTRACE_BTS_O_ALLOC) {
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bts_ovfl_callback_t ovfl = NULL;
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unsigned int sig = 0;
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error = -EINVAL;
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if (cfg.size < (10 * bts_cfg.sizeof_bts))
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goto errout;
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if (cfg.flags & PTRACE_BTS_O_SIGNAL) {
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if (!cfg.signal)
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goto errout;
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error = -EOPNOTSUPP;
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goto errout;
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sig = cfg.signal;
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}
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if (child->bts) {
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(void)ds_release_bts(child->bts);
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kfree(child->bts_buffer);
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child->bts = NULL;
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child->bts_buffer = NULL;
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}
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error = -ENOMEM;
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child->bts_buffer = kzalloc(cfg.size, GFP_KERNEL);
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if (!child->bts_buffer)
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goto errout;
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child->bts = ds_request_bts(child, child->bts_buffer, cfg.size,
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ovfl, /* th = */ (size_t)-1);
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if (IS_ERR(child->bts)) {
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error = PTR_ERR(child->bts);
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kfree(child->bts_buffer);
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child->bts = NULL;
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child->bts_buffer = NULL;
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goto errout;
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}
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child->thread.bts_ovfl_signal = sig;
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if (child->bts) {
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ds_release_bts(child->bts);
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child->bts = NULL;
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}
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error = -EINVAL;
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if (!child->thread.ds_ctx && cfg.flags)
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goto errout;
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if (cfg.flags & PTRACE_BTS_O_SIGNAL) {
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if (!cfg.signal)
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return -EINVAL;
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return -EOPNOTSUPP;
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child->thread.bts_ovfl_signal = cfg.signal;
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}
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if ((cfg.flags & PTRACE_BTS_O_ALLOC) &&
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(cfg.size != child->bts_size)) {
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kfree(child->bts_buffer);
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child->bts_size = cfg.size;
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child->bts_buffer = kzalloc(cfg.size, GFP_KERNEL);
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if (!child->bts_buffer) {
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child->bts_size = 0;
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return -ENOMEM;
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}
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}
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if (cfg.flags & PTRACE_BTS_O_TRACE)
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child->thread.debugctlmsr |= bts_cfg.debugctl_mask;
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else
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child->thread.debugctlmsr &= ~bts_cfg.debugctl_mask;
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flags |= BTS_USER;
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if (cfg.flags & PTRACE_BTS_O_SCHED)
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set_tsk_thread_flag(child, TIF_BTS_TRACE_TS);
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else
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clear_tsk_thread_flag(child, TIF_BTS_TRACE_TS);
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flags |= BTS_TIMESTAMPS;
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error = sizeof(cfg);
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child->bts = ds_request_bts(child, child->bts_buffer, child->bts_size,
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/* ovfl = */ NULL, /* th = */ (size_t)-1,
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flags);
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if (IS_ERR(child->bts)) {
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int error = PTR_ERR(child->bts);
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out:
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if (child->thread.debugctlmsr)
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set_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
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else
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clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
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kfree(child->bts_buffer);
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child->bts = NULL;
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child->bts_buffer = NULL;
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child->bts_size = 0;
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return error;
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return error;
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}
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errout:
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child->thread.debugctlmsr &= ~bts_cfg.debugctl_mask;
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clear_tsk_thread_flag(child, TIF_BTS_TRACE_TS);
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goto out;
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return sizeof(cfg);
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}
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static int ptrace_bts_status(struct task_struct *child,
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long cfg_size,
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struct ptrace_bts_config __user *ucfg)
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{
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const struct bts_trace *trace;
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struct ptrace_bts_config cfg;
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size_t end;
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const void *base, *max;
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int error;
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if (cfg_size < sizeof(cfg))
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return -EIO;
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error = ds_get_bts_end(child->bts, &end);
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if (error < 0)
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return error;
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error = ds_access_bts(child->bts, /* index = */ 0, &base);
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if (error < 0)
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return error;
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error = ds_access_bts(child->bts, /* index = */ end, &max);
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if (error < 0)
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return error;
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trace = ds_read_bts(child->bts);
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if (!trace)
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return -EPERM;
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memset(&cfg, 0, sizeof(cfg));
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cfg.size = (max - base);
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cfg.size = trace->ds.end - trace->ds.begin;
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cfg.signal = child->thread.bts_ovfl_signal;
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cfg.bts_size = sizeof(struct bts_struct);
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if (cfg.signal)
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cfg.flags |= PTRACE_BTS_O_SIGNAL;
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if (test_tsk_thread_flag(child, TIF_DEBUGCTLMSR) &&
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child->thread.debugctlmsr & bts_cfg.debugctl_mask)
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if (trace->ds.flags & BTS_USER)
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cfg.flags |= PTRACE_BTS_O_TRACE;
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if (test_tsk_thread_flag(child, TIF_BTS_TRACE_TS))
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if (trace->ds.flags & BTS_TIMESTAMPS)
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cfg.flags |= PTRACE_BTS_O_SCHED;
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if (copy_to_user(ucfg, &cfg, sizeof(cfg)))
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@@ -873,105 +746,28 @@ static int ptrace_bts_status(struct task_struct *child,
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return sizeof(cfg);
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}
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static int ptrace_bts_write_record(struct task_struct *child,
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const struct bts_struct *in)
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static int ptrace_bts_clear(struct task_struct *child)
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{
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unsigned char bts_record[BTS_MAX_RECORD_SIZE];
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const struct bts_trace *trace;
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if (BTS_MAX_RECORD_SIZE < bts_cfg.sizeof_bts)
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return -EOVERFLOW;
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trace = ds_read_bts(child->bts);
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if (!trace)
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return -EPERM;
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memset(bts_record, 0, bts_cfg.sizeof_bts);
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switch (in->qualifier) {
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case BTS_INVALID:
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break;
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memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size);
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case BTS_BRANCH:
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bts_set(bts_record, bts_from, in->variant.lbr.from_ip);
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bts_set(bts_record, bts_to, in->variant.lbr.to_ip);
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break;
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case BTS_TASK_ARRIVES:
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case BTS_TASK_DEPARTS:
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bts_set(bts_record, bts_from, bts_escape);
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bts_set(bts_record, bts_qual, in->qualifier);
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bts_set(bts_record, bts_jiffies, in->variant.jiffies);
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break;
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default:
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return -EINVAL;
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}
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return ds_write_bts(child->bts, bts_record, bts_cfg.sizeof_bts);
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return ds_reset_bts(child->bts);
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}
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void ptrace_bts_take_timestamp(struct task_struct *tsk,
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enum bts_qualifier qualifier)
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static int ptrace_bts_size(struct task_struct *child)
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{
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struct bts_struct rec = {
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.qualifier = qualifier,
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.variant.jiffies = jiffies_64
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};
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const struct bts_trace *trace;
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ptrace_bts_write_record(tsk, &rec);
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}
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trace = ds_read_bts(child->bts);
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if (!trace)
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return -EPERM;
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static const struct bts_configuration bts_cfg_netburst = {
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.sizeof_bts = sizeof(long) * 3,
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.sizeof_field = sizeof(long),
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.debugctl_mask = (1<<2)|(1<<3)|(1<<5)
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};
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static const struct bts_configuration bts_cfg_pentium_m = {
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.sizeof_bts = sizeof(long) * 3,
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.sizeof_field = sizeof(long),
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.debugctl_mask = (1<<6)|(1<<7)
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};
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static const struct bts_configuration bts_cfg_core2 = {
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.sizeof_bts = 8 * 3,
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.sizeof_field = 8,
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.debugctl_mask = (1<<6)|(1<<7)|(1<<9)
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};
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static inline void bts_configure(const struct bts_configuration *cfg)
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{
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bts_cfg = *cfg;
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}
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void __cpuinit ptrace_bts_init_intel(struct cpuinfo_x86 *c)
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{
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switch (c->x86) {
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case 0x6:
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switch (c->x86_model) {
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case 0 ... 0xC:
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/* sorry, don't know about them */
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break;
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case 0xD:
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case 0xE: /* Pentium M */
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bts_configure(&bts_cfg_pentium_m);
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break;
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default: /* Core2, Atom, ... */
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bts_configure(&bts_cfg_core2);
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break;
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}
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break;
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case 0xF:
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switch (c->x86_model) {
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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:
|
||||
|
||||
Reference in New Issue
Block a user