From 74ebb63e7cd25f6fb02a45fc2ea7735bce1217c9 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Mon, 14 Sep 2009 16:49:28 -0400 Subject: [PATCH] tracing/kprobes: Fix profiling alignment for perf_counter buffer Fix *probe_profile_func() to align buffer size, since perf_counter requires its buffer entries to be 8 bytes aligned. Signed-off-by: Masami Hiramatsu Acked-by: Steven Rostedt Cc: Jim Keniston Cc: Ananth N Mavinakayanahalli Cc: Andi Kleen Cc: Christoph Hellwig Cc: Frank Ch. Eigler Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Jason Baron Cc: K.Prasad Cc: Lai Jiangshan Cc: Li Zefan Cc: Peter Zijlstra Cc: Srikar Dronamraju Cc: Tom Zanussi LKML-Reference: <20090914204928.18779.60029.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Frederic Weisbecker --- kernel/trace/trace_kprobe.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 70b632c3bd08..d8db9357489b 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -1149,18 +1149,23 @@ 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, i, pc; + int size, __size, i, pc; unsigned long irq_flags; local_save_flags(irq_flags); pc = preempt_count(); - size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args); + __size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args); + size = ALIGN(__size + sizeof(u32), sizeof(u64)); + size -= sizeof(u32); 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; @@ -1183,13 +1188,15 @@ 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, i, pc; + int size, __size, i, pc; unsigned long irq_flags; local_save_flags(irq_flags); pc = preempt_count(); - size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args); + __size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args); + size = ALIGN(__size + sizeof(u32), sizeof(u64)); + size -= sizeof(u32); do { char raw_data[size]; -- 2.20.1