From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932892AbZKZEft (ORCPT ); Wed, 25 Nov 2009 23:35:49 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932306AbZKZEfn (ORCPT ); Wed, 25 Nov 2009 23:35:43 -0500 Received: from mail-ew0-f219.google.com ([209.85.219.219]:46712 "EHLO mail-ew0-f219.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932749AbZKZEfl (ORCPT ); Wed, 25 Nov 2009 23:35:41 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; b=EZYuJIGXQ1/ZyBBwtG9wr4ajvylE+mtYo145aUogDPcNrzXdkh8nh58Qf6Eq+6vnqI 3In7hqSssCbXjSY4oI7tlb/BJ/LnP+EF2BqsztA6lgR3rTuwfgB/Pw8v1g38HBA+NPcZ CLhT5nN7ZLVlOT5/KTexflWXRbdG29MCDkRu0= From: Frederic Weisbecker To: Ingo Molnar Cc: LKML , Frederic Weisbecker , Peter Zijlstra , Arnaldo Carvalho de Melo , Paul Mackerras , Steven Rostedt , Prasad Subject: [PATCH 3/3] hw-breakpoints: Simplify error handling in breakpoint creation requests Date: Thu, 26 Nov 2009 05:35:42 +0100 Message-Id: <1259210142-5714-3-git-send-regression-fweisbec@gmail.com> X-Mailer: git-send-email 1.6.2.3 In-Reply-To: <1259210142-5714-1-git-send-regression-fweisbec@gmail.com> References: <1259210142-5714-1-git-send-regression-fweisbec@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This simplifies the error handling when we create a breakpoint. We don't need anymore to check the NULL return value corner case since we have improved perf_event_create_kernel_counter() to always return an error code in fail case. Signed-off-by: Frederic Weisbecker Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Paul Mackerras Cc: Steven Rostedt Cc: Prasad --- arch/x86/kernel/ptrace.c | 8 +------- kernel/hw_breakpoint.c | 4 ++-- kernel/trace/trace_ksym.c | 16 ++++------------ samples/hw_breakpoint/data_breakpoint.c | 3 --- 4 files changed, 7 insertions(+), 24 deletions(-) diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index b25f894..75e0cd8 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -657,10 +657,7 @@ restore: tsk, true); thread->ptrace_bps[i] = NULL; - if (!bp) { /* incorrect bp, or we have a bug in bp API */ - rc = -EINVAL; - break; - } + /* Incorrect bp, or we have a bug in bp API */ if (IS_ERR(bp)) { rc = PTR_ERR(bp); bp = NULL; @@ -729,9 +726,6 @@ static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr, tsk, bp->attr.disabled); } - - if (!bp) - return -EIO; /* * CHECKME: the previous code returned -EIO if the addr wasn't a * valid task virtual addr. The new one will return -EINVAL in this diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c index 06d372f..dd3fb4a 100644 --- a/kernel/hw_breakpoint.c +++ b/kernel/hw_breakpoint.c @@ -442,7 +442,7 @@ register_wide_hw_breakpoint(unsigned long addr, *pevent = bp; - if (IS_ERR(bp) || !bp) { + if (IS_ERR(bp)) { err = PTR_ERR(bp); goto fail; } @@ -453,7 +453,7 @@ register_wide_hw_breakpoint(unsigned long addr, fail: for_each_possible_cpu(cpu) { pevent = per_cpu_ptr(cpu_events, cpu); - if (IS_ERR(*pevent) || !*pevent) + if (IS_ERR(*pevent)) break; unregister_hw_breakpoint(*pevent); } diff --git a/kernel/trace/trace_ksym.c b/kernel/trace/trace_ksym.c index 9f040e4..c538b15 100644 --- a/kernel/trace/trace_ksym.c +++ b/kernel/trace/trace_ksym.c @@ -200,12 +200,9 @@ int process_new_ksym_entry(char *ksymname, int op, unsigned long addr) entry->ksym_hbp = register_wide_hw_breakpoint(entry->ksym_addr, entry->len, entry->type, ksym_hbp_handler, true); + if (IS_ERR(entry->ksym_hbp)) { - entry->ksym_hbp = NULL; ret = PTR_ERR(entry->ksym_hbp); - } - - if (!entry->ksym_hbp) { printk(KERN_INFO "ksym_tracer request failed. Try again" " later!!\n"); goto err; @@ -332,21 +329,16 @@ static ssize_t ksym_trace_filter_write(struct file *file, if (changed) { unregister_wide_hw_breakpoint(entry->ksym_hbp); entry->type = op; + ret = 0; if (op > 0) { entry->ksym_hbp = register_wide_hw_breakpoint(entry->ksym_addr, entry->len, entry->type, ksym_hbp_handler, true); if (IS_ERR(entry->ksym_hbp)) - entry->ksym_hbp = NULL; - - /* modified without problem */ - if (entry->ksym_hbp) { - ret = 0; + ret = PTR_ERR(entry->ksym_hbp); + else goto out; - } - } else { - ret = 0; } /* Error or "symbol:---" case: drop it */ ksym_filter_entry_count--; diff --git a/samples/hw_breakpoint/data_breakpoint.c b/samples/hw_breakpoint/data_breakpoint.c index 9506381..ee7f9fb 100644 --- a/samples/hw_breakpoint/data_breakpoint.c +++ b/samples/hw_breakpoint/data_breakpoint.c @@ -61,9 +61,6 @@ static int __init hw_break_module_init(void) if (IS_ERR(sample_hbp)) { ret = PTR_ERR(sample_hbp); goto fail; - } else if (!sample_hbp) { - ret = -EINVAL; - goto fail; } printk(KERN_INFO "HW Breakpoint for %s write installed\n", ksym_name); -- 1.6.2.3