From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e23smtp09.au.ibm.com (e23smtp09.au.ibm.com [202.81.31.142]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e23smtp09.au.ibm.com", Issuer "Equifax" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id F0C05B71A6 for ; Wed, 23 Jun 2010 20:04:03 +1000 (EST) Received: from d23relay04.au.ibm.com (d23relay04.au.ibm.com [202.81.31.246]) by e23smtp09.au.ibm.com (8.14.4/8.13.1) with ESMTP id o5NA40Ln024944 for ; Wed, 23 Jun 2010 20:04:00 +1000 Received: from d23av04.au.ibm.com (d23av04.au.ibm.com [9.190.235.139]) by d23relay04.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id o5NA432k1544194 for ; Wed, 23 Jun 2010 20:04:03 +1000 Received: from d23av04.au.ibm.com (loopback [127.0.0.1]) by d23av04.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id o5NA42xl007111 for ; Wed, 23 Jun 2010 20:04:03 +1000 From: "Ian Munsie" To: linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org Subject: [PATCH 01/40] ftrace syscalls: don't add events for unmapped syscalls Date: Wed, 23 Jun 2010 20:02:42 +1000 Message-Id: <1277287401-28571-2-git-send-email-imunsie@au1.ibm.com> In-Reply-To: <1277287401-28571-1-git-send-email-imunsie@au1.ibm.com> References: <1277287401-28571-1-git-send-email-imunsie@au1.ibm.com> Cc: Frederic Weisbecker , Jason Baron , Steven Rostedt , Ingo Molnar , Paul Mackerras , Ian Munsie , Ingo Molnar , Masami Hiramatsu List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Ian Munsie FTRACE_SYSCALLS would create events for each and every system call, even if it had failed to map the system call's name with it's number. This resulted in a number of events being created that would not behave as expected. This could happen, for example, on architectures who's symbol names are unusual and will not match the system call name. It could also happen with system calls which were mapped to sys_ni_syscall. This patch changes the default system call number in the metadata to -1. If the system call name from the metadata is not successfully mapped to a system call number during boot, than the event initialisation routine will now return an error, preventing the event from being created. Signed-off-by: Ian Munsie --- include/linux/syscalls.h | 2 ++ kernel/trace/trace_syscalls.c | 8 ++++++++ 2 files changed, 10 insertions(+), 0 deletions(-) diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 7f614ce..86f082b 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -159,6 +159,7 @@ extern struct trace_event_functions exit_syscall_print_funcs; __attribute__((section("__syscalls_metadata"))) \ __syscall_meta_##sname = { \ .name = "sys"#sname, \ + .syscall_nr = -1, /* Filled in at boot */ \ .nb_args = nb, \ .types = types_##sname, \ .args = args_##sname, \ @@ -176,6 +177,7 @@ extern struct trace_event_functions exit_syscall_print_funcs; __attribute__((section("__syscalls_metadata"))) \ __syscall_meta__##sname = { \ .name = "sys_"#sname, \ + .syscall_nr = -1, /* Filled in at boot */ \ .nb_args = 0, \ .enter_event = &event_enter__##sname, \ .exit_event = &event_exit__##sname, \ diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index 34e3580..82246ce 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -431,6 +431,14 @@ void unreg_event_syscall_exit(struct ftrace_event_call *call) int init_syscall_trace(struct ftrace_event_call *call) { int id; + int num; + + num = ((struct syscall_metadata *)call->data)->syscall_nr; + if (num < 0 || num >= NR_syscalls) { + pr_debug("syscall %s metadata not mapped, disabling ftrace event\n", + ((struct syscall_metadata *)call->data)->name); + return -ENOSYS; + } if (set_syscall_print_fmt(call) < 0) return -ENOMEM; -- 1.7.1