From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752516Ab0FWKEI (ORCPT ); Wed, 23 Jun 2010 06:04:08 -0400 Received: from e23smtp06.au.ibm.com ([202.81.31.148]:59715 "EHLO e23smtp06.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752264Ab0FWKEF (ORCPT ); Wed, 23 Jun 2010 06:04:05 -0400 From: "Ian Munsie" To: linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org Cc: Jason Baron , Frederic Weisbecker , Steven Rostedt , Ingo Molnar , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Ian Munsie , Ingo Molnar , Masami Hiramatsu 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> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1277287401-28571-1-git-send-email-imunsie@au1.ibm.com> References: <1277287401-28571-1-git-send-email-imunsie@au1.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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