The exclude of crashk_res, crashk_low_res and crashk_cma memory are almost identical across different architectures, so handling them in the crash core would eliminate a lot of duplication, so do them in the common code. Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> --- arch/arm64/kernel/machine_kexec_file.c | 12 ------- arch/loongarch/kernel/machine_kexec_file.c | 12 ------- arch/powerpc/kexec/ranges.c | 16 ++------- arch/riscv/kernel/machine_kexec_file.c | 5 +-- arch/x86/kernel/crash.c | 39 ++-------------------- kernel/crash_core.c | 28 ++++++++++++++++ 6 files changed, 34 insertions(+), 78 deletions(-) diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c index 410060ebd86d..ed2c45007158 100644 --- a/arch/arm64/kernel/machine_kexec_file.c +++ b/arch/arm64/kernel/machine_kexec_file.c @@ -64,20 +64,8 @@ static int prepare_elf_headers(void **addr, unsigned long *sz) cmem->nr_ranges++; } - /* 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; } diff --git a/arch/loongarch/kernel/machine_kexec_file.c b/arch/loongarch/kernel/machine_kexec_file.c index fb57026f5f25..26f867e53955 100644 --- a/arch/loongarch/kernel/machine_kexec_file.c +++ b/arch/loongarch/kernel/machine_kexec_file.c @@ -80,20 +80,8 @@ static int prepare_elf_headers(void **addr, unsigned long *sz) cmem->nr_ranges++; } - /* Exclude crashkernel region */ - ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end); - if (ret < 0) - goto out; - - if (crashk_low_res.end) { - ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end); - if (ret < 0) - goto out; - } - ret = crash_prepare_elf64_headers(cmem, true, addr, sz); -out: kfree(cmem); return ret; } diff --git a/arch/powerpc/kexec/ranges.c b/arch/powerpc/kexec/ranges.c index 867135560e5c..3f76dd266b1f 100644 --- a/arch/powerpc/kexec/ranges.c +++ b/arch/powerpc/kexec/ranges.c @@ -553,9 +553,7 @@ int get_usable_memory_ranges(struct crash_mem **mem_ranges) #endif /* CONFIG_KEXEC_FILE */ #ifdef CONFIG_CRASH_DUMP -static int crash_exclude_mem_range_guarded(struct crash_mem **mem_ranges, - unsigned long long mstart, - unsigned long long mend) +static int crash_realloc_mem_range_guarded(struct crash_mem **mem_ranges) { struct crash_mem *tmem = *mem_ranges; @@ -566,7 +564,7 @@ static int crash_exclude_mem_range_guarded(struct crash_mem **mem_ranges, return -ENOMEM; } - return crash_exclude_mem_range(tmem, mstart, mend); + return 0; } /** @@ -604,18 +602,10 @@ int get_crash_memory_ranges(struct crash_mem **mem_ranges) sort_memory_ranges(*mem_ranges, true); } - /* Exclude crashkernel region */ - ret = crash_exclude_mem_range_guarded(mem_ranges, crashk_res.start, crashk_res.end); + ret = crash_realloc_mem_range_guarded(mem_ranges); if (ret) goto out; - for (i = 0; i < crashk_cma_cnt; ++i) { - ret = crash_exclude_mem_range_guarded(mem_ranges, crashk_cma_ranges[i].start, - crashk_cma_ranges[i].end); - if (ret) - goto out; - } - /* * FIXME: For now, stay in parity with kexec-tools but if RTAS/OPAL * regions are exported to save their context at the time of diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c index dd9d92a96517..fec3622a13c9 100644 --- a/arch/riscv/kernel/machine_kexec_file.c +++ b/arch/riscv/kernel/machine_kexec_file.c @@ -74,10 +74,7 @@ static int prepare_elf_headers(void **addr, unsigned long *sz) if (ret) goto out; - /* 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); + ret = crash_prepare_elf64_headers(cmem, true, addr, sz); out: kfree(cmem); diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c index 335fd2ee9766..d8341a48f6b3 100644 --- a/arch/x86/kernel/crash.c +++ b/arch/x86/kernel/crash.c @@ -186,41 +186,6 @@ static struct crash_mem *fill_up_crash_elf_data(void) return cmem; } -/* - * Look for any unwanted ranges between mstart, mend and remove them. This - * might lead to split and split ranges are put in cmem->ranges[] array - */ -static int elf_header_exclude_ranges(struct crash_mem *cmem) -{ - int ret = 0; - int i; - - /* Exclude the low 1M because it is always reserved */ - ret = crash_exclude_mem_range(cmem, 0, SZ_1M - 1); - if (ret) - return ret; - - /* Exclude crashkernel region */ - ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end); - if (ret) - return ret; - - if (crashk_low_res.end) - ret = crash_exclude_mem_range(cmem, crashk_low_res.start, - crashk_low_res.end); - if (ret) - return ret; - - for (i = 0; i < crashk_cma_cnt; ++i) { - ret = crash_exclude_mem_range(cmem, crashk_cma_ranges[i].start, - crashk_cma_ranges[i].end); - if (ret) - return ret; - } - - return 0; -} - static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg) { struct crash_mem *cmem = arg; @@ -247,8 +212,8 @@ static int prepare_elf_headers(void **addr, unsigned long *sz, if (ret) goto out; - /* Exclude unwanted mem ranges */ - ret = elf_header_exclude_ranges(cmem); + /* Exclude the low 1M because it is always reserved */ + ret = crash_exclude_mem_range(cmem, 0, SZ_1M - 1); if (ret) goto out; diff --git a/kernel/crash_core.c b/kernel/crash_core.c index 99dac1aa972a..5c0de111ddc3 100644 --- a/kernel/crash_core.c +++ b/kernel/crash_core.c @@ -18,6 +18,7 @@ #include <linux/memblock.h> #include <linux/kmemleak.h> #include <linux/crash_core.h> +#include <linux/crash_reserve.h> #include <linux/reboot.h> #include <linux/btf.h> #include <linux/objtool.h> @@ -161,8 +162,30 @@ static inline resource_size_t crash_resource_size(const struct resource *res) return !res->end ? 0 : resource_size(res); } +static int crash_exclude_mem_ranges(struct crash_mem *cmem) +{ + int ret, i; + + /* Exclude crashkernel region */ + ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end); + if (ret) + return ret; + + if (crashk_low_res.end) { + ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end); + if (ret) + return ret; + } + for (i = 0; i < crashk_cma_cnt; ++i) { + ret = crash_exclude_mem_range(cmem, crashk_cma_ranges[i].start, + crashk_cma_ranges[i].end); + if (ret) + return ret; + } + return ret; +} int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map, void **addr, unsigned long *sz) @@ -174,6 +197,11 @@ int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map, unsigned int cpu, i; unsigned long long notes_addr; unsigned long mstart, mend; + int ret; + + ret = crash_exclude_mem_ranges(mem); + if (ret) + return ret; /* extra phdr for vmcoreinfo ELF note */ nr_phdr = nr_cpus + 1; -- 2.34.1

Commit 35c18f2933c5 ("Add a new optional ",cma" suffix to the crashkernel= command line option") and commit ab475510e042 ("kdump: implement reserve_crashkernel_cma") added CMA support for kdump crashkernel reservation. This allows the kernel to dynamically allocate contiguous memory for crash dumping when needed, rather than permanently reserving a fixed region at boot time. So extend crashkernel CMA reservation support to riscv. The following changes are made to enable CMA reservation: - Parse and obtain the CMA reservation size along with other crashkernel parameters. - Call reserve_crashkernel_cma() to allocate the CMA region for kdump. - Include the CMA-reserved ranges for kdump kernel to use. - Exclude the CMA-reserved ranges from the crash kernel memory to prevent them from being exported through /proc/vmcore. Update kernel-parameters.txt to document CMA support for crashkernel on riscv architecture. Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> --- Documentation/admin-guide/kernel-parameters.txt | 16 ++++++++-------- arch/riscv/kernel/machine_kexec_file.c | 10 ++++++++-- arch/riscv/mm/init.c | 5 +++-- 3 files changed, 19 insertions(+), 12 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 36bb642a7edd..3b92324d3a03 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1119,14 +1119,14 @@ Kernel parameters It will be ignored when crashkernel=X,high is not used or memory reserved is below 4G. crashkernel=size[KMG],cma - [KNL, X86, ARM64, ppc] Reserve additional crash kernel memory from - CMA. This reservation is usable by the first system's - userspace memory and kernel movable allocations (memory - balloon, zswap). Pages allocated from this memory range - will not be included in the vmcore so this should not - be used if dumping of userspace memory is intended and - it has to be expected that some movable kernel pages - may be missing from the dump. + [KNL, X86, ARM64, RISCV, ppc] Reserve additional crash + kernel memory from CMA. This reservation is usable by + the first system's userspace memory and kernel movable + allocations (memory balloon, zswap). Pages allocated + from this memory range will not be included in the vmcore + so this should not be used if dumping of userspace memory + is intended and it has to be expected that some movable + kernel pages may be missing from the dump. A standard crashkernel reservation, as described above, is still needed to hold the crash kernel and initrd. diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c index fec3622a13c9..0e4ac70d5a9a 100644 --- a/arch/riscv/kernel/machine_kexec_file.c +++ b/arch/riscv/kernel/machine_kexec_file.c @@ -59,9 +59,9 @@ static int prepare_elf_headers(void **addr, unsigned long *sz) { struct crash_mem *cmem; unsigned int nr_ranges; - int ret; + int ret, i; - nr_ranges = 1; /* For exclusion of crashkernel region */ + nr_ranges = 1 + crashk_cma_cnt; /* For exclusion of crashkernel region */ walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback); cmem = kmalloc(struct_size(cmem, ranges, nr_ranges), GFP_KERNEL); @@ -74,6 +74,12 @@ static int prepare_elf_headers(void **addr, unsigned long *sz) if (ret) goto out; + for (i = 0; i < crashk_cma_cnt; i++) { + cmem->ranges[cmem->nr_ranges].start = crashk_cma_ranges[i].start; + cmem->ranges[cmem->nr_ranges].end = crashk_cma_ranges[i].end; + cmem->nr_ranges++; + } + ret = crash_prepare_elf64_headers(cmem, true, addr, sz); out: diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index addb8a9305be..074d2d5f79ee 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -1404,7 +1404,7 @@ static inline void setup_vm_final(void) */ static void __init arch_reserve_crashkernel(void) { - unsigned long long low_size = 0; + unsigned long long low_size = 0, cma_size = 0; unsigned long long crash_base, crash_size; bool high = false; int ret; @@ -1414,11 +1414,12 @@ static void __init arch_reserve_crashkernel(void) ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), &crash_size, &crash_base, - &low_size, NULL, &high); + &low_size, &cma_size, &high); if (ret) return; reserve_crashkernel_generic(crash_size, crash_base, low_size, high); + reserve_crashkernel_cma(cma_size); } void __init paging_init(void) -- 2.34.1