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Harding" , linuxppc-dev@lists.ozlabs.org Subject: [PATCH v2 02/10] powerpc/traps: Return early in show_signal_msg() Date: Fri, 27 Jul 2018 11:58:03 -0300 X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180727145811.12334-1-muriloo@linux.ibm.com> References: <20180727145811.12334-1-muriloo@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 18072714-0064-0000-0000-000003308A58 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00009438; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000266; SDB=6.01066907; UDB=6.00548186; IPR=6.00844773; MB=3.00022354; MTD=3.00000008; XFM=3.00000015; UTC=2018-07-27 14:58:58 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18072714-0065-0000-0000-00003A17164C Message-Id: <20180727145811.12334-3-muriloo@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-07-27_06:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1806210000 definitions=main-1807270153 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Modify the logic of show_signal_msg() to return early, if possible. Replace printk_ratelimited() by printk() and a default rate limit burst to limit displaying unhandled signals messages. Mainly reason of this change is to improve readability of the function. The conditions to display the message were coupled together in one single `if` statement. Splitting out the rate limit check outside show_signal_msg() makes it easier to the caller decide if it wants to respect a printk rate limit or not. Signed-off-by: Murilo Opsfelder Araujo --- arch/powerpc/kernel/traps.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index cbd3dc365193..4faab4705774 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -301,6 +301,13 @@ void user_single_step_siginfo(struct task_struct *tsk, info->si_addr = (void __user *)regs->nip; } +static bool show_unhandled_signals_ratelimited(void) +{ + static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL, + DEFAULT_RATELIMIT_BURST); + return show_unhandled_signals && __ratelimit(&rs); +} + static void show_signal_msg(int signr, struct pt_regs *regs, int code, unsigned long addr) { @@ -309,11 +316,12 @@ static void show_signal_msg(int signr, struct pt_regs *regs, int code, const char fmt64[] = KERN_INFO "%s[%d]: unhandled signal %d " \ "at %016lx nip %016lx lr %016lx code %x\n"; - if (show_unhandled_signals && unhandled_signal(current, signr)) { - printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32, - current->comm, current->pid, signr, - addr, regs->nip, regs->link, code); - } + if (!unhandled_signal(current, signr)) + return; + + printk(regs->msr & MSR_64BIT ? fmt64 : fmt32, + current->comm, current->pid, signr, + addr, regs->nip, regs->link, code); } void _exception_pkey(int signr, struct pt_regs *regs, int code, @@ -326,7 +334,8 @@ void _exception_pkey(int signr, struct pt_regs *regs, int code, return; } - show_signal_msg(signr, regs, code, addr); + if (show_unhandled_signals_ratelimited()) + show_signal_msg(signr, regs, code, addr); if (arch_irqs_disabled() && !arch_irq_disabled_regs(regs)) local_irq_enable(); -- 2.17.1