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tracing/kprobes: Use global event perf buffers in kprobe tracer

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Use new percpu global event buffer instead of stack in kprobe
tracer while tracing through perf.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <20090925182011.10157.60140.stgit@omoto>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
This commit is contained in:
Masami Hiramatsu 2009-09-25 11:20:12 -07:00 committed by Frederic Weisbecker
parent d7a4b414ee
commit a1a138d05f
1 changed files with 70 additions and 39 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

109
kernel/trace/trace_kprobe.c
View File

@ -1149,35 +1149,49 @@ static __kprobes int kprobe_profile_func(struct kprobe *kp,
struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
struct ftrace_event_call *call = &tp->call;
struct kprobe_trace_entry *entry;
int size, __size, i, pc;
struct trace_entry *ent;
int size, __size, i, pc, __cpu;
unsigned long irq_flags;
char *raw_data;
local_save_flags(irq_flags);
pc = preempt_count();
__size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args);
size = ALIGN(__size + sizeof(u32), sizeof(u64));
size -= sizeof(u32);
if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE,
"profile buffer not large enough"))
return 0;
do {
char raw_data[size];
struct trace_entry *ent;
/*
* Zero dead bytes from alignment to avoid stack leak
* to userspace
*/
*(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
entry = (struct kprobe_trace_entry *)raw_data;
ent = &entry->ent;
/*
* Protect the non nmi buffer
* This also protects the rcu read side
*/
local_irq_save(irq_flags);
__cpu = smp_processor_id();
tracing_generic_entry_update(ent, irq_flags, pc);
ent->type = call->id;
entry->nargs = tp->nr_args;
entry->ip = (unsigned long)kp->addr;
for (i = 0; i < tp->nr_args; i++)
entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
perf_tp_event(call->id, entry->ip, 1, entry, size);
} while (0);
if (in_nmi())
raw_data = rcu_dereference(trace_profile_buf_nmi);
else
raw_data = rcu_dereference(trace_profile_buf);
if (!raw_data)
goto end;
raw_data = per_cpu_ptr(raw_data, __cpu);
/* Zero dead bytes from alignment to avoid buffer leak to userspace */
*(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
entry = (struct kprobe_trace_entry *)raw_data;
ent = &entry->ent;
tracing_generic_entry_update(ent, irq_flags, pc);
ent->type = call->id;
entry->nargs = tp->nr_args;
entry->ip = (unsigned long)kp->addr;
for (i = 0; i < tp->nr_args; i++)
entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
perf_tp_event(call->id, entry->ip, 1, entry, size);
end:
local_irq_restore(irq_flags);
return 0;
}
@ -1188,33 +1202,50 @@ static __kprobes int kretprobe_profile_func(struct kretprobe_instance *ri,
struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
struct ftrace_event_call *call = &tp->call;
struct kretprobe_trace_entry *entry;
int size, __size, i, pc;
struct trace_entry *ent;
int size, __size, i, pc, __cpu;
unsigned long irq_flags;
char *raw_data;
local_save_flags(irq_flags);
pc = preempt_count();
__size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args);
size = ALIGN(__size + sizeof(u32), sizeof(u64));
size -= sizeof(u32);
if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE,
"profile buffer not large enough"))
return 0;
do {
char raw_data[size];
struct trace_entry *ent;
/*
* Protect the non nmi buffer
* This also protects the rcu read side
*/
local_irq_save(irq_flags);
__cpu = smp_processor_id();
*(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
entry = (struct kretprobe_trace_entry *)raw_data;
ent = &entry->ent;
if (in_nmi())
raw_data = rcu_dereference(trace_profile_buf_nmi);
else
raw_data = rcu_dereference(trace_profile_buf);
tracing_generic_entry_update(ent, irq_flags, pc);
ent->type = call->id;
entry->nargs = tp->nr_args;
entry->func = (unsigned long)tp->rp.kp.addr;
entry->ret_ip = (unsigned long)ri->ret_addr;
for (i = 0; i < tp->nr_args; i++)
entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
perf_tp_event(call->id, entry->ret_ip, 1, entry, size);
} while (0);
if (!raw_data)
goto end;
raw_data = per_cpu_ptr(raw_data, __cpu);
/* Zero dead bytes from alignment to avoid buffer leak to userspace */
*(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
entry = (struct kretprobe_trace_entry *)raw_data;
ent = &entry->ent;
tracing_generic_entry_update(ent, irq_flags, pc);
ent->type = call->id;
entry->nargs = tp->nr_args;
entry->func = (unsigned long)tp->rp.kp.addr;
entry->ret_ip = (unsigned long)ri->ret_addr;
for (i = 0; i < tp->nr_args; i++)
entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
perf_tp_event(call->id, entry->ret_ip, 1, entry, size);
end:
local_irq_restore(irq_flags);
return 0;
}