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([144.202.108.46]) by smtp.gmail.com with ESMTPSA id s9-20020a056a00178900b006ce789d8022sm20232551pfg.59.2023.12.19.08.34.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 19 Dec 2023 08:34:30 -0800 (PST) From: Yuntao Wang To: akpm@linux-foundation.org Cc: bhe@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, dyoung@redhat.com, hbathini@linux.ibm.com, hpa@zytor.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, mingo@redhat.com, seanjc@google.com, tglx@linutronix.de, tiwai@suse.de, vgoyal@redhat.com, x86@kernel.org, ytcoode@gmail.com Subject: [PATCH] crash_core: optimize crash_exclude_mem_range() Date: Wed, 20 Dec 2023 00:34:18 +0800 Message-ID: <20231219163418.108591-1-ytcoode@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231218092902.9fae480cfcad3874e9e7236f@linux-foundation.org> References: <20231218092902.9fae480cfcad3874e9e7236f@linux-foundation.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231219_083433_440090_00C68DAA X-CRM114-Status: GOOD ( 11.22 ) X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.org Because memory ranges in mem->ranges are stored in ascending order, when we detect `p_end < start`, we can break the for loop early, as the subsequent memory ranges must also be outside the range we are looking for. Signed-off-by: Yuntao Wang --- Hi Andrew, Patch "[PATCH 2/2] crash_core: fix out-of-bounds access check in crash_exclude_mem_range()" can be ignored, use this patch instead. kernel/crash_core.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/kernel/crash_core.c b/kernel/crash_core.c index 9a219a918638..d425c4a106cd 100644 --- a/kernel/crash_core.c +++ b/kernel/crash_core.c @@ -575,9 +575,12 @@ int crash_exclude_mem_range(struct crash_mem *mem, p_start = mstart; p_end = mend; - if (p_start > end || p_end < start) + if (p_start > end) continue; + if (p_end < start) + break; + /* Truncate any area outside of range */ if (p_start < start) p_start = start; -- 2.43.0 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec