From mboxrd@z Thu Jan 1 00:00:00 1970 From: Masami Hiramatsu Subject: [PATCH -tip v14 09/12] tracing: Kprobe-tracer supports more than 6 arguments Date: Thu, 13 Aug 2009 16:35:18 -0400 Message-ID: <20090813203518.31965.96979.stgit@localhost.localdomain> References: <20090813203403.31965.20973.stgit@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Cc: systemtap, kvm, DLE, Masami Hiramatsu , Ananth N Mavinakayanahalli , Avi Kivity , Andi Kleen , Christoph Hellwig , "Frank Ch. Eigler" , Frederic Weisbecker , "H. Peter Anvin" , Ingo Molnar , Jason Baron , Jim Keniston , "K.Prasad" , Lai Jiangshan , Li Zefan , =?utf-8?q?Przemys=C5=82aw?= =?utf-8?q?Pawe=C5=82czyk?= , Roland McGrath , Sam Ravnborg , Srikar Drona To: Ingo Molnar , Steven Rostedt , lkml Return-path: In-Reply-To: <20090813203403.31965.20973.stgit@localhost.localdomain> List-Unsubscribe: List-Subscribe: List-Post: List-Help: , Sender: systemtap-owner@sourceware.org List-Id: kvm.vger.kernel.org Support up to 128 arguments for each kprobes event. Signed-off-by: Masami Hiramatsu Cc: Ananth N Mavinakayanahalli Cc: Avi Kivity Cc: Andi Kleen Cc: Christoph Hellwig Cc: Frank Ch. Eigler Cc: Frederic Weisbecker Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Jason Baron Cc: Jim Keniston Cc: K.Prasad Cc: Lai Jiangshan Cc: Li Zefan Cc: Przemysław Pawełczyk Cc: Roland McGrath Cc: Sam Ravnborg Cc: Srikar Dronamraju Cc: Steven Rostedt Cc: Tom Zanussi Cc: Vegard Nossum --- Documentation/trace/kprobetrace.txt | 2 +- kernel/trace/trace_kprobe.c | 21 +++++++++++++-------- 2 files changed, 14 insertions(+), 9 deletions(-) diff --git a/Documentation/trace/kprobetrace.txt b/Documentation/trace/kprobetrace.txt index efff6eb..c9c09b4 100644 --- a/Documentation/trace/kprobetrace.txt +++ b/Documentation/trace/kprobetrace.txt @@ -32,7 +32,7 @@ Synopsis of kprobe_events SYMBOL[+offs|-offs] : Symbol+offset where the probe is inserted. MEMADDR : Address where the probe is inserted. - FETCHARGS : Arguments. + FETCHARGS : Arguments. Each probe can have up to 128 args. %REG : Fetch register REG sN : Fetch Nth entry of stack (N >= 0) sa : Fetch stack address. diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index d92877a..4704e40 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -32,7 +32,7 @@ #include "trace.h" #include "trace_output.h" -#define TRACE_KPROBE_ARGS 6 +#define MAX_TRACE_ARGS 128 #define MAX_ARGSTR_LEN 63 /* currently, trace_kprobe only supports X86. */ @@ -184,11 +184,15 @@ struct trace_probe { struct kretprobe rp; }; const char *symbol; /* symbol name */ - unsigned int nr_args; - struct fetch_func args[TRACE_KPROBE_ARGS]; struct ftrace_event_call call; + unsigned int nr_args; + struct fetch_func args[]; }; +#define SIZEOF_TRACE_PROBE(n) \ + (offsetof(struct trace_probe, args) + \ + (sizeof(struct fetch_func) * (n))) + static int kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs); static int kretprobe_trace_func(struct kretprobe_instance *ri, struct pt_regs *regs); @@ -263,11 +267,11 @@ static DEFINE_MUTEX(probe_lock); static LIST_HEAD(probe_list); static struct trace_probe *alloc_trace_probe(const char *symbol, - const char *event) + const char *event, int nargs) { struct trace_probe *tp; - tp = kzalloc(sizeof(struct trace_probe), GFP_KERNEL); + tp = kzalloc(SIZEOF_TRACE_PROBE(nargs), GFP_KERNEL); if (!tp) return ERR_PTR(-ENOMEM); @@ -573,9 +577,10 @@ static int create_trace_probe(int argc, char **argv) if (offset && is_return) return -EINVAL; } + argc -= 2; argv += 2; /* setup a probe */ - tp = alloc_trace_probe(symbol, event); + tp = alloc_trace_probe(symbol, event, argc); if (IS_ERR(tp)) return PTR_ERR(tp); @@ -594,8 +599,8 @@ static int create_trace_probe(int argc, char **argv) kp->addr = addr; /* parse arguments */ - argc -= 2; argv += 2; ret = 0; - for (i = 0; i < argc && i < TRACE_KPROBE_ARGS; i++) { + ret = 0; + for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { if (strlen(argv[i]) > MAX_ARGSTR_LEN) { pr_info("Argument%d(%s) is too long.\n", i, argv[i]); ret = -ENOSPC; -- Masami Hiramatsu Software Engineer Hitachi Computer Products (America), Inc. Software Solutions Division e-mail: mhiramat@redhat.com