Re: [PATCH v16 06/10] riscv: kexec_file: Use crash_prepare_headers() helper to simplify code
From: Jinjie Ruan <hidden>
Date: 2026-06-18 01:55:08
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linux-devicetree, linux-doc, linux-riscv, lkml, loongarch
On 6/8/2026 3:34 PM, Jinjie Ruan wrote:
Use the newly introduced crash_prepare_headers() function to replace the existing prepare_elf_headers(), allocate cmem and exclude crash kernel memory in the crash core, which reduce code duplication. Only the following two architecture functions need to be implemented: - arch_get_system_nr_ranges(). Call get_nr_ram_ranges_callback() to pre-counts the max number of memory ranges. - arch_crash_populate_cmem(). Use prepare_elf64_ram_headers_callback() to collects the memory ranges and fills them into cmem.
Hi Paul, Palmer, Albert, Alexandre and RISC-V maintainers, Sorry for the interruption. This patch set aims to clean up and refactor the crash memory allocation and the exclusion logic of crashk_res, crashk_low_res, and crashk_cma. Currently, these routines are almost identical across different architectures, leading to a lot of duplicated code. This series consolidates the logic into the generic crash core, removing redundant implementations from architecture-specific directories, including arch/riscv. There are no functional changes intended for RISC-V. The patches will be queued in the liveupdate tree for wider testing. Could you please take a look at the RISC-V side and consider providing an Acked-by? The patch series can be reviewed here: https://lore.kernel.org/all/20260608073459.3119290-1-ruanjinjie@huawei.com/ (local) Thank you very much for your time and review! Best regards, Jinjie
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Cc: Paul Walmsley <pjw@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Guo Ren <guoren@kernel.org> Reviewed-by: Sourabh Jain <redacted> Acked-by: Baoquan He <redacted> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Signed-off-by: Jinjie Ruan <redacted> --- arch/riscv/kernel/machine_kexec_file.c | 47 +++++++------------------- 1 file changed, 12 insertions(+), 35 deletions(-)diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c index 3f7766057cac..439cbc50dfa6 100644 --- a/arch/riscv/kernel/machine_kexec_file.c +++ b/arch/riscv/kernel/machine_kexec_file.c@@ -44,6 +44,15 @@ static int get_nr_ram_ranges_callback(struct resource *res, void *arg) return 0; } +unsigned int arch_get_system_nr_ranges(void) +{ + unsigned int nr_ranges = 2; /* For exclusion of crashkernel region */ + + walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback); + + return nr_ranges; +} + static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg) { struct crash_mem *cmem = arg;@@ -55,41 +64,9 @@ static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg) return 0; } -static int prepare_elf_headers(void **addr, unsigned long *sz) +int arch_crash_populate_cmem(struct crash_mem *cmem) { - struct crash_mem *cmem; - unsigned int nr_ranges; - int ret; - - nr_ranges = 2; /* For exclusion of crashkernel region */ - walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback); - - cmem = kmalloc_flex(*cmem, ranges, nr_ranges); - if (!cmem) - return -ENOMEM; - - cmem->max_nr_ranges = nr_ranges; - cmem->nr_ranges = 0; - ret = walk_system_ram_res(0, -1, cmem, prepare_elf64_ram_headers_callback); - if (ret) - goto out; - - /* Exclude crashkernel region */ - ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end); - if (ret) - goto out; - - if (crashk_low_res.end) { - ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end); - if (ret) - goto out; - } - - ret = crash_prepare_elf64_headers(cmem, true, addr, sz); - -out: - kfree(cmem); - return ret; + return walk_system_ram_res(0, -1, cmem, prepare_elf64_ram_headers_callback); } static char *setup_kdump_cmdline(struct kimage *image, char *cmdline,@@ -281,7 +258,7 @@ int load_extra_segments(struct kimage *image, unsigned long kernel_start, if (image->type == KEXEC_TYPE_CRASH) { void *headers; unsigned long headers_sz; - ret = prepare_elf_headers(&headers, &headers_sz); + ret = crash_prepare_headers(true, &headers, &headers_sz, NULL); if (ret) { pr_err("Preparing elf core header failed\n"); goto out;