| Message ID | 20180724065759.19186-13-takahiro.akashi@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: kexec: add kexec_file_load() support | expand |
Hi Akashi, On 24/07/18 07:57, AKASHI Takahiro wrote: > Enabling crash dump (kdump) includes > * prepare contents of ELF header of a core dump file, /proc/vmcore, > using crash_prepare_elf64_headers(), and > * add two device tree properties, "linux,usable-memory-range" and > "linux,elfcorehdr", which represent respectively a memory range > to be used by crash dump kernel and the header's location > diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h > index 5d102a1054b3..1b2c27026ae0 100644 > --- a/arch/arm64/include/asm/kexec.h > +++ b/arch/arm64/include/asm/kexec.h > @@ -97,8 +97,12 @@ static inline void crash_post_resume(void) {} > #define ARCH_HAS_KIMAGE_ARCH > > struct kimage_arch { > - void *dtb_buf; > + void *dtb; This change should be in an earlier patch, otherwise this series doesn't build during bisect. With the build-issues fixed: Reviewed-by: James Morse <james.morse@arm.com> Some boring Nits: > unsigned long dtb_mem; > + /* Core ELF header buffer */ > + void *elf_headers; > + unsigned long elf_headers_mem; > + unsigned long elf_headers_sz; > }; > diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c > index b8297f10e2ef..7356da5a53d5 100644 > --- a/arch/arm64/kernel/machine_kexec_file.c > +++ b/arch/arm64/kernel/machine_kexec_file.c > @@ -38,12 +44,30 @@ static int setup_dtb(struct kimage *image, > void **dtb_buf, unsigned long *dtb_buf_len) > { > void *buf = NULL; > - size_t buf_size; > + size_t buf_size, range_size; > int nodeoffset; > int ret; > > /* duplicate dt blob */ > buf_size = fdt_totalsize(initial_boot_params); > + range_size = of_fdt_reg_cells_size(); > + > + if (image->type == KEXEC_TYPE_CRASH) { > + buf_size += fdt_prop_len("linux,elfcorehdr", range_size); > + buf_size += fdt_prop_len("linux,usable-memory-range", > + range_size); > + } Nit: it would be better if these strings were defined in a header file somewhere so we don't risk a typo if this gets refactored. > @@ -129,6 +170,43 @@ static int setup_dtb(struct kimage *image, > return ret; > } > > +static int prepare_elf_headers(void **addr, unsigned long *sz) > +{ > + struct crash_mem *cmem; > + unsigned int nr_ranges; > + int ret; > + u64 i; > + phys_addr_t start, end; > + > + nr_ranges = 1; /* for exclusion of crashkernel region */ > + for_each_mem_range(i, &memblock.memory, NULL, NUMA_NO_NODE, 0, > + &start, &end, NULL) Nit: MEMBLOCK_NONE Thanks, James
On Thu, Jul 26, 2018 at 02:36:58PM +0100, James Morse wrote: > Hi Akashi, > > On 24/07/18 07:57, AKASHI Takahiro wrote: > > Enabling crash dump (kdump) includes > > * prepare contents of ELF header of a core dump file, /proc/vmcore, > > using crash_prepare_elf64_headers(), and > > * add two device tree properties, "linux,usable-memory-range" and > > "linux,elfcorehdr", which represent respectively a memory range > > to be used by crash dump kernel and the header's location > > > diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h > > index 5d102a1054b3..1b2c27026ae0 100644 > > --- a/arch/arm64/include/asm/kexec.h > > +++ b/arch/arm64/include/asm/kexec.h > > @@ -97,8 +97,12 @@ static inline void crash_post_resume(void) {} > > #define ARCH_HAS_KIMAGE_ARCH > > > > struct kimage_arch { > > > - void *dtb_buf; > > + void *dtb; > > This change should be in an earlier patch, otherwise this series doesn't build > during bisect. Will fix. > With the build-issues fixed: > Reviewed-by: James Morse <james.morse@arm.com> > > Some boring Nits: > > > unsigned long dtb_mem; > > + /* Core ELF header buffer */ > > + void *elf_headers; > > + unsigned long elf_headers_mem; > > + unsigned long elf_headers_sz; > > }; > > diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c > > index b8297f10e2ef..7356da5a53d5 100644 > > --- a/arch/arm64/kernel/machine_kexec_file.c > > +++ b/arch/arm64/kernel/machine_kexec_file.c > > @@ -38,12 +44,30 @@ static int setup_dtb(struct kimage *image, > > void **dtb_buf, unsigned long *dtb_buf_len) > > { > > void *buf = NULL; > > - size_t buf_size; > > + size_t buf_size, range_size; > > int nodeoffset; > > int ret; > > > > /* duplicate dt blob */ > > buf_size = fdt_totalsize(initial_boot_params); > > + range_size = of_fdt_reg_cells_size(); > > + > > + if (image->type == KEXEC_TYPE_CRASH) { > > + buf_size += fdt_prop_len("linux,elfcorehdr", range_size); > > + buf_size += fdt_prop_len("linux,usable-memory-range", > > + range_size); > > + } > > Nit: it would be better if these strings were defined in a header file somewhere > so we don't risk a typo if this gets refactored. Nit?? Well, I do understand your concern, but it's a bit headache. If we handle them in such a way, we may want to handle others, such as linux,initrd-start/end, chosen and bootargs, as well in this file. They are not kexec specific and should go into a common header. This will end up propagating similar changes to other no-kexec-related occurrences under drivers/of. So I want to keep the following def's local in this file for easy maintenance. #define FDT_PSTR_KEXEC_ELFHDR "linux,elfcorehdr" #define FDT_PSTR_MEM_RANGE "linux,usable-memory-range" #define FDT_PSTR_INITRD_ST "linux,initrd-start" #define FDT_PSTR_INITRD_END "linux,initrd-end" #define FDT_PSTR_BOOTARGS "bootargs" #define FDT_PSTR_KASLR_SEED "kaslr-seed" > > > > @@ -129,6 +170,43 @@ static int setup_dtb(struct kimage *image, > > return ret; > > } > > > > +static int prepare_elf_headers(void **addr, unsigned long *sz) > > +{ > > + struct crash_mem *cmem; > > + unsigned int nr_ranges; > > + int ret; > > + u64 i; > > + phys_addr_t start, end; > > + > > + nr_ranges = 1; /* for exclusion of crashkernel region */ > > > + for_each_mem_range(i, &memblock.memory, NULL, NUMA_NO_NODE, 0, > > + &start, &end, NULL) > > Nit: MEMBLOCK_NONE OK -Takahiro AKASHI > > Thanks, > > James
diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h index 5d102a1054b3..1b2c27026ae0 100644 --- a/arch/arm64/include/asm/kexec.h +++ b/arch/arm64/include/asm/kexec.h @@ -97,8 +97,12 @@ static inline void crash_post_resume(void) {} #define ARCH_HAS_KIMAGE_ARCH struct kimage_arch { - void *dtb_buf; + void *dtb; unsigned long dtb_mem; + /* Core ELF header buffer */ + void *elf_headers; + unsigned long elf_headers_mem; + unsigned long elf_headers_sz; }; /** diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c index b8297f10e2ef..7356da5a53d5 100644 --- a/arch/arm64/kernel/machine_kexec_file.c +++ b/arch/arm64/kernel/machine_kexec_file.c @@ -16,7 +16,9 @@ #include <linux/libfdt.h> #include <linux/memblock.h> #include <linux/of_fdt.h> +#include <linux/slab.h> #include <linux/types.h> +#include <linux/vmalloc.h> #include <asm/byteorder.h> const struct kexec_file_ops * const kexec_file_loaders[] = { @@ -29,6 +31,10 @@ int arch_kimage_file_post_load_cleanup(struct kimage *image) vfree(image->arch.dtb); image->arch.dtb = NULL; + vfree(image->arch.elf_headers); + image->arch.elf_headers = NULL; + image->arch.elf_headers_sz = 0; + return kexec_image_post_load_cleanup_default(image); } @@ -38,12 +44,30 @@ static int setup_dtb(struct kimage *image, void **dtb_buf, unsigned long *dtb_buf_len) { void *buf = NULL; - size_t buf_size; + size_t buf_size, range_size; int nodeoffset; int ret; + /* check ranges against root's #address-cells and #size-cells */ + if (image->type == KEXEC_TYPE_CRASH && + (!of_fdt_cells_size_fitted(image->arch.elf_headers_mem, + image->arch.elf_headers_sz) || + !of_fdt_cells_size_fitted(crashk_res.start, + crashk_res.end - crashk_res.start + 1))) { + pr_err("Crash memory region doesn't fit into DT's root cell sizes.\n"); + ret = -EINVAL; + goto out_err; + } + /* duplicate dt blob */ buf_size = fdt_totalsize(initial_boot_params); + range_size = of_fdt_reg_cells_size(); + + if (image->type == KEXEC_TYPE_CRASH) { + buf_size += fdt_prop_len("linux,elfcorehdr", range_size); + buf_size += fdt_prop_len("linux,usable-memory-range", + range_size); + } if (initrd_load_addr) { /* can be redundant, but trimmed at the end */ @@ -73,6 +97,23 @@ static int setup_dtb(struct kimage *image, goto out_err; } + if (image->type == KEXEC_TYPE_CRASH) { + /* add linux,elfcorehdr */ + ret = fdt_setprop_reg(buf, nodeoffset, "linux,elfcorehdr", + image->arch.elf_headers_mem, + image->arch.elf_headers_sz); + if (ret) + goto out_err; + + /* add linux,usable-memory-range */ + ret = fdt_setprop_reg(buf, nodeoffset, + "linux,usable-memory-range", + crashk_res.start, + crashk_res.end - crashk_res.start + 1); + if (ret) + goto out_err; + } + /* add bootargs */ if (cmdline) { ret = fdt_setprop_string(buf, nodeoffset, "bootargs", cmdline); @@ -129,6 +170,43 @@ static int setup_dtb(struct kimage *image, return ret; } +static int prepare_elf_headers(void **addr, unsigned long *sz) +{ + struct crash_mem *cmem; + unsigned int nr_ranges; + int ret; + u64 i; + phys_addr_t start, end; + + nr_ranges = 1; /* for exclusion of crashkernel region */ + for_each_mem_range(i, &memblock.memory, NULL, NUMA_NO_NODE, 0, + &start, &end, NULL) + nr_ranges++; + + cmem = kmalloc(sizeof(struct crash_mem) + + sizeof(struct crash_mem_range) * nr_ranges, GFP_KERNEL); + if (!cmem) + return -ENOMEM; + + cmem->max_nr_ranges = nr_ranges; + cmem->nr_ranges = 0; + for_each_mem_range(i, &memblock.memory, NULL, NUMA_NO_NODE, + MEMBLOCK_NONE, &start, &end, NULL) { + cmem->ranges[cmem->nr_ranges].start = start; + cmem->ranges[cmem->nr_ranges].end = end - 1; + cmem->nr_ranges++; + } + + /* 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); + + kfree(cmem); + return ret; +} + int load_other_segments(struct kimage *image, unsigned long kernel_load_addr, unsigned long kernel_size, @@ -136,14 +214,43 @@ int load_other_segments(struct kimage *image, char *cmdline, unsigned long cmdline_len) { struct kexec_buf kbuf; - void *dtb = NULL; - unsigned long initrd_load_addr = 0, dtb_len; + void *headers, *dtb = NULL; + unsigned long headers_sz, initrd_load_addr = 0, dtb_len; int ret = 0; kbuf.image = image; /* not allocate anything below the kernel */ kbuf.buf_min = kernel_load_addr + kernel_size; + /* load elf core header */ + if (image->type == KEXEC_TYPE_CRASH) { + ret = prepare_elf_headers(&headers, &headers_sz); + if (ret) { + pr_err("Preparing elf core header failed\n"); + goto out_err; + } + + kbuf.buffer = headers; + kbuf.bufsz = headers_sz; + kbuf.mem = 0; + kbuf.memsz = headers_sz; + kbuf.buf_align = SZ_64K; /* largest supported page size */ + kbuf.buf_max = ULONG_MAX; + kbuf.top_down = true; + + ret = kexec_add_buffer(&kbuf); + if (ret) { + vfree(headers); + goto out_err; + } + image->arch.elf_headers = headers; + image->arch.elf_headers_mem = kbuf.mem; + image->arch.elf_headers_sz = headers_sz; + + pr_debug("Loaded elf core header at 0x%lx bufsz=0x%lx memsz=0x%lx\n", + image->arch.elf_headers_mem, headers_sz, headers_sz); + } + /* load initrd */ if (initrd) { kbuf.buffer = initrd;
Enabling crash dump (kdump) includes * prepare contents of ELF header of a core dump file, /proc/vmcore, using crash_prepare_elf64_headers(), and * add two device tree properties, "linux,usable-memory-range" and "linux,elfcorehdr", which represent respectively a memory range to be used by crash dump kernel and the header's location Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> --- arch/arm64/include/asm/kexec.h | 6 +- arch/arm64/kernel/machine_kexec_file.c | 113 ++++++++++++++++++++++++- 2 files changed, 115 insertions(+), 4 deletions(-)