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([2601:647:6881:9060:bc87:d8fe:3e55:7ffb]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-b6a76b6f302sm4332032a12.38.2025.10.18.23.17.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 18 Oct 2025 23:17:12 -0700 (PDT) From: Cong Wang To: linux-kernel@vger.kernel.org Cc: jiri@resnulli.us, stefanha@redhat.com, multikernel@lists.linux.dev, pasha.tatashin@soleen.com, Cong Wang , Andrew Morton , Baoquan He , Alexander Graf , Mike Rapoport , Changyuan Lyu , kexec@lists.infradead.org, linux-mm@kvack.org Subject: [RFC Patch v2 11/16] kexec: Add /proc/kimage interface for kimage tracking Date: Sat, 18 Oct 2025 23:16:25 -0700 Message-Id: <20251019061631.2235405-12-xiyou.wangcong@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20251019061631.2235405-1-xiyou.wangcong@gmail.com> References: <20251019061631.2235405-1-xiyou.wangcong@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 1830D180006 X-Stat-Signature: cciwwpi4wcxkak1xpj319rrtwgy7tm7n X-Rspam-User: X-HE-Tag: 1760854633-330163 X-HE-Meta: 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 sGYOOd5a uOCyTZogNAbZ4WwKUh9sZMrLAD/V4HE9HW0pn7aEH+V5don36QAlOX0yR3T5ikXJWUYpj92ZYGN0fczTG8BvDpUKLFefQetPXsPCmgryVQQf0P3hopxA/1iqk8ZD1xXLAwFhB X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Cong Wang Add a dedicated /proc/kimage file to provide read-only access to all loaded kernel images in the system, for both regular kexec kernel images and multikernel images. The interface displays kernel images in a tabular format showing: - Type: kexec type (default, crash, multikernel) - Start Address: entry point in hexadecimal format - Segments: number of memory segments This interface is particularly useful for inspecting kimages, debugging kexec, and verifying that kernel images are loaded correctly. Signed-off-by: Cong Wang --- kernel/kexec_core.c | 63 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c index ed5c97b4531e..7db755e64dd6 100644 --- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c @@ -13,6 +13,8 @@ #include #include #include +#include +#include #include #include #include @@ -1214,6 +1216,52 @@ struct kimage *kexec_image; struct kimage *kexec_crash_image; static int kexec_load_disabled; +/* + * Proc interface for /proc/kimage + */ +static int kimage_proc_show(struct seq_file *m, void *v) +{ + struct kimage *image; + const char *type_names[] = { + [KEXEC_TYPE_DEFAULT] = "default", + [KEXEC_TYPE_CRASH] = "crash", + [KEXEC_TYPE_MULTIKERNEL] = "multikernel" + }; + + seq_printf(m, "MK_ID Type Start Address Segments\n"); + seq_printf(m, "----- ---------- -------------- --------\n"); + + kimage_list_lock(); + if (list_empty(&kexec_image_list)) { + seq_printf(m, "No kimages loaded\n"); + } else { + list_for_each_entry(image, &kexec_image_list, list) { + const char *type_name = "unknown"; + + if (image->type < ARRAY_SIZE(type_names) && type_names[image->type]) + type_name = type_names[image->type]; + + seq_printf(m, "%5d %-10s 0x%012lx %8lu\n", + image->mk_id, type_name, image->start, image->nr_segments); + } + } + kimage_list_unlock(); + + return 0; +} + +static int kimage_proc_open(struct inode *inode, struct file *file) +{ + return single_open(file, kimage_proc_show, NULL); +} + +static const struct proc_ops kimage_proc_ops = { + .proc_open = kimage_proc_open, + .proc_read = seq_read, + .proc_lseek = seq_lseek, + .proc_release = single_release, +}; + #ifdef CONFIG_SYSCTL static int kexec_limit_handler(const struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos) @@ -1285,6 +1333,21 @@ static int __init kexec_core_sysctl_init(void) late_initcall(kexec_core_sysctl_init); #endif +static int __init kimage_proc_init(void) +{ + struct proc_dir_entry *entry; + + entry = proc_create("kimage", 0444, NULL, &kimage_proc_ops); + if (!entry) { + pr_err("Failed to create /proc/kimage\n"); + return -ENOMEM; + } + + pr_debug("Created /proc/kimage interface\n"); + return 0; +} +late_initcall(kimage_proc_init); + bool kexec_load_permitted(int kexec_image_type) { struct kexec_load_limit *limit; -- 2.34.1