From 5fc6e7d45373571d03cd04fd4c6069c0a97fa75a Mon Sep 17 00:00:00 2001 From: Jinjie Ruan Date: Mon, 29 Jun 2026 17:47:37 +0800 Subject: [PATCH] riscv: kexec_file: Fix crashk_low_res not exclude bug As done in commit 944a45abfabc ("arm64: kdump: Reimplement crashkernel=X") and commit 4831be702b95 ("arm64/kexec: Fix missing extra range for crashkres_low.") for arm64, while implementing crashkernel=X,[high,low], riscv should have excluded the "crashk_low_res" reserved ranges from the crash kernel memory to prevent them from being exported through /proc/vmcore, and the exclusion would need an extra crash_mem range. Just simply tested on qemu with crashkernel=4G with kexec in [1] mentioned in [2]. And the second kernel can be started normally. # dmesg | grep crash [ 0.000000] crashkernel low memory reserved: 0xf8000000 - 0x100000000 (128 MB) [ 0.000000] crashkernel reserved: 0x000000017fe00000 - 0x000000027fe00000 (4096 MB) [1]: https://github.com/chenjh005/kexec-tools/tree/build-test-riscv-v2 [2]: https://lore.kernel.org/all/20230726175000.2536220-1-chenjiahao16@huawei.com/ Cc: Guo Ren Cc: Baoquan He Fixes: 5882e5acf18d ("riscv: kdump: Implement crashkernel=X,[high,low]") Reviewed-by: Guo Ren Signed-off-by: Jinjie Ruan Link: https://github.com/chenjh005/kexec-tools/tree/build-test-riscv-v2 Link: https://lore.kernel.org/all/20230726175000.2536220-1-chenjiahao16@huawei.com/ Link: https://patch.msgid.link/20260629094746.191843-2-ruanjinjie@huawei.com Signed-off-by: Mike Rapoport (Microsoft) --- arch/riscv/kernel/machine_kexec_file.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c index 59d4bbc848a8..fa2946aa9b8f 100644 --- a/arch/riscv/kernel/machine_kexec_file.c +++ b/arch/riscv/kernel/machine_kexec_file.c @@ -62,7 +62,7 @@ static int prepare_elf_headers(void **addr, unsigned long *sz) unsigned int nr_ranges; int ret; - nr_ranges = 1; /* For exclusion of crashkernel region */ + 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); @@ -77,8 +77,16 @@ static int prepare_elf_headers(void **addr, unsigned long *sz) /* Exclude crashkernel region */ ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end); - if (!ret) - ret = crash_prepare_elf64_headers(cmem, true, addr, sz); + 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);