{"id":2218962,"url":"http://patchwork.ozlabs.org/api/patches/2218962/?format=json","web_url":"http://patchwork.ozlabs.org/project/linuxppc-dev/patch/20260402072701.628293-9-ruanjinjie@huawei.com/","project":{"id":2,"url":"http://patchwork.ozlabs.org/api/projects/2/?format=json","name":"Linux PPC development","link_name":"linuxppc-dev","list_id":"linuxppc-dev.lists.ozlabs.org","list_email":"linuxppc-dev@lists.ozlabs.org","web_url":"https://github.com/linuxppc/wiki/wiki","scm_url":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git","webscm_url":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/","list_archive_url":"https://lore.kernel.org/linuxppc-dev/","list_archive_url_format":"https://lore.kernel.org/linuxppc-dev/{}/","commit_url_format":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/commit/?id={}"},"msgid":"<20260402072701.628293-9-ruanjinjie@huawei.com>","list_archive_url":"https://lore.kernel.org/linuxppc-dev/20260402072701.628293-9-ruanjinjie@huawei.com/","date":"2026-04-02T07:26:54","name":"[v12,08/15] crash: Add crash_prepare_headers() to exclude crash kernel memory","commit_ref":null,"pull_url":null,"state":"handled-elsewhere","archived":false,"hash":"b33cded3ed0a0e9fd2f39db3aa0c96c97b0bdf25","submitter":{"id":84791,"url":"http://patchwork.ozlabs.org/api/people/84791/?format=json","name":"Jinjie Ruan","email":"ruanjinjie@huawei.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/linuxppc-dev/patch/20260402072701.628293-9-ruanjinjie@huawei.com/mbox/","series":[{"id":498443,"url":"http://patchwork.ozlabs.org/api/series/498443/?format=json","web_url":"http://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=498443","date":"2026-04-02T07:26:46","name":"arm64/riscv: Add support for crashkernel CMA reservation","version":12,"mbox":"http://patchwork.ozlabs.org/series/498443/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2218962/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2218962/checks/","tags":{},"related":[],"headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linuxppc-dev@lists.ozlabs.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (1024-bit key;\n unprotected) header.d=huawei.com header.i=@huawei.com header.a=rsa-sha256\n header.s=dkim header.b=fqpO3Hvp;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org\n (client-ip=2404:9400:21b9:f100::1; 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a=rsa-sha256; d=huawei.com; s=dkim;\n\tc=relaxed/relaxed; q=dns/txt;\n\th=From;\n\tbh=a5oa/1akbFaboX4rfV7+Vg9uBkAhjnDcb7jWorQ4YFU=;\n\tb=fqpO3HvpIjuAcuK0qAVSEZLAj73VpXyTH01PSTMPaRqRwgyGBa4gPp9dgSa5NyKMyIXjIrgPm\n\tAQxT8ME9ISrCOTJjv/+U1ydwIc7H0xGh87cLN+Up5FXVPDzghq6wk2BpjRl0Go8AXaMJRDhGs7V\n\t9ihJ7PMu9s3QAj+Hj82lfYw=","From":"Jinjie Ruan ","To":", , ,\n\t, , ,\n\t, , ,\n\t, , ,\n\t, , ,\n\t, , ,\n\t, , ,\n\t, , ,\n\t, , ,\n\t, ,\n\t, , ,\n\t, , ,\n\t, , ,\n\t, , ,\n\t, , ,\n\t, , ,\n\t, , ,\n\t, ,\n\t, , ,\n\t, ,\n\t, ,\n\t, ,\n\t, ,\n\t","CC":"","Subject":"[PATCH v12 08/15] crash: Add crash_prepare_headers() to exclude crash\n kernel memory","Date":"Thu, 2 Apr 2026 15:26:54 +0800","Message-ID":"<20260402072701.628293-9-ruanjinjie@huawei.com>","X-Mailer":"git-send-email 2.34.1","In-Reply-To":"<20260402072701.628293-1-ruanjinjie@huawei.com>","References":"<20260402072701.628293-1-ruanjinjie@huawei.com>","X-Mailing-List":"linuxppc-dev@lists.ozlabs.org","List-Id":"","List-Help":"","List-Owner":"","List-Post":"","List-Archive":",\n ","List-Subscribe":",\n ,\n ","List-Unsubscribe":"","Precedence":"list","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","Content-Type":"text/plain","X-Originating-IP":"[10.90.53.73]","X-ClientProxiedBy":"kwepems100002.china.huawei.com (7.221.188.206) To\n dggpemf500011.china.huawei.com (7.185.36.131)","X-Spam-Status":"No, score=-0.2 required=3.0 tests=DKIM_SIGNED,DKIM_VALID,\n\tDKIM_VALID_AU,DKIM_VALID_EF,SPF_HELO_NONE,SPF_PASS autolearn=disabled\n\tversion=4.0.1 OzLabs 8","X-Spam-Checker-Version":"SpamAssassin 4.0.1 (2024-03-25) on lists.ozlabs.org"},"content":"The crash memory alloc, and the exclude of crashk_res, crashk_low_res\nand crashk_cma memory are almost identical across different architectures,\nhandling them in the crash core would eliminate a lot of duplication, so\nadd crash_prepare_headers() helper to handle them in the common code.\n\nTo achieve the above goal, three architecture-specific functions are\nintroduced:\n\n- arch_get_system_nr_ranges(). Pre-counts the max number of memory ranges.\n\n- arch_crash_populate_cmem(). Collects the memory ranges and fills them\n into cmem.\n\n- arch_crash_exclude_ranges(). Architecture's additional crash memory\n ranges exclusion, defaulting to empty.\n\nReviewed-by: Sourabh Jain \nAcked-by: Baoquan He \nAcked-by: Mike Rapoport (Microsoft) \nSigned-off-by: Jinjie Ruan \n---\n include/linux/crash_core.h | 5 +++\n kernel/crash_core.c | 82 ++++++++++++++++++++++++++++++++++++--\n 2 files changed, 84 insertions(+), 3 deletions(-)","diff":"diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h\nindex d35726d6a415..033b20204aca 100644\n--- a/include/linux/crash_core.h\n+++ b/include/linux/crash_core.h\n@@ -66,6 +66,8 @@ extern int crash_exclude_mem_range(struct crash_mem *mem,\n \t\t\t\t unsigned long long mend);\n extern int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map,\n \t\t\t\t void **addr, unsigned long *sz);\n+extern int crash_prepare_headers(int need_kernel_map, void **addr,\n+\t\t\t\t unsigned long *sz, unsigned long *nr_mem_ranges);\n \n struct kimage;\n struct kexec_segment;\n@@ -83,6 +85,9 @@ int kexec_should_crash(struct task_struct *p);\n int kexec_crash_loaded(void);\n void crash_save_cpu(struct pt_regs *regs, int cpu);\n extern int kimage_crash_copy_vmcoreinfo(struct kimage *image);\n+extern unsigned int arch_get_system_nr_ranges(void);\n+extern int arch_crash_populate_cmem(struct crash_mem *cmem);\n+extern int arch_crash_exclude_ranges(struct crash_mem *cmem);\n \n #else /* !CONFIG_CRASH_DUMP*/\n struct pt_regs;\ndiff --git a/kernel/crash_core.c b/kernel/crash_core.c\nindex 2c1a3791e410..96a96e511f5a 100644\n--- a/kernel/crash_core.c\n+++ b/kernel/crash_core.c\n@@ -170,9 +170,6 @@ static inline resource_size_t crash_resource_size(const struct resource *res)\n \treturn !res->end ? 0 : resource_size(res);\n }\n \n-\n-\n-\n int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map,\n \t\t\t void **addr, unsigned long *sz)\n {\n@@ -274,6 +271,85 @@ int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map,\n \treturn 0;\n }\n \n+static struct crash_mem *alloc_cmem(unsigned int nr_ranges)\n+{\n+\tstruct crash_mem *cmem;\n+\n+\tcmem = kvzalloc_flex(*cmem, ranges, nr_ranges);\n+\tif (!cmem)\n+\t\treturn NULL;\n+\n+\tcmem->max_nr_ranges = nr_ranges;\n+\treturn cmem;\n+}\n+\n+unsigned int __weak arch_get_system_nr_ranges(void) { return 0; }\n+int __weak arch_crash_populate_cmem(struct crash_mem *cmem) { return -1; }\n+int __weak arch_crash_exclude_ranges(struct crash_mem *cmem) { return 0; }\n+\n+static int crash_exclude_core_ranges(struct crash_mem *cmem)\n+{\n+\tint ret, i;\n+\n+\t/* Exclude crashkernel region */\n+\tret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);\n+\tif (ret)\n+\t\treturn ret;\n+\n+\tif (crashk_low_res.end) {\n+\t\tret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);\n+\t\tif (ret)\n+\t\t\treturn ret;\n+\t}\n+\n+\tfor (i = 0; i < crashk_cma_cnt; ++i) {\n+\t\tret = crash_exclude_mem_range(cmem, crashk_cma_ranges[i].start,\n+\t\t\t\t\t crashk_cma_ranges[i].end);\n+\t\tif (ret)\n+\t\t\treturn ret;\n+\t}\n+\n+\treturn 0;\n+}\n+\n+int crash_prepare_headers(int need_kernel_map, void **addr, unsigned long *sz,\n+\t\t\t unsigned long *nr_mem_ranges)\n+{\n+\tunsigned int max_nr_ranges;\n+\tstruct crash_mem *cmem;\n+\tint ret;\n+\n+\tmax_nr_ranges = arch_get_system_nr_ranges();\n+\tif (!max_nr_ranges)\n+\t\treturn -ENOMEM;\n+\n+\tcmem = alloc_cmem(max_nr_ranges);\n+\tif (!cmem)\n+\t\treturn -ENOMEM;\n+\n+\tret = arch_crash_populate_cmem(cmem);\n+\tif (ret)\n+\t\tgoto out;\n+\n+\tret = crash_exclude_core_ranges(cmem);\n+\tif (ret)\n+\t\tgoto out;\n+\n+\tret = arch_crash_exclude_ranges(cmem);\n+\tif (ret)\n+\t\tgoto out;\n+\n+\t/* Return the computed number of memory ranges, for hotplug usage */\n+\tif (nr_mem_ranges)\n+\t\t*nr_mem_ranges = cmem->nr_ranges;\n+\n+\tret = crash_prepare_elf64_headers(cmem, need_kernel_map, addr, sz);\n+\n+out:\n+\tkvfree(cmem);\n+\treturn ret;\n+}\n+\n /**\n * crash_exclude_mem_range - exclude a mem range for existing ranges\n * @mem: mem->range contains an array of ranges sorted in ascending order\n","prefixes":["v12","08/15"]}