Provide an arm64-specific implementation for arch_kexec_locate_mem_hole(), using the resource tree instead of memblock, and respecting the reservations added by EFI.
This ensures that kexec_file is finally reliable. Reported-by: Moritz Fischer <[email protected]> Signed-off-by: Marc Zyngier <[email protected]> --- arch/arm64/kernel/kexec_image.c | 45 +++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) diff --git a/arch/arm64/kernel/kexec_image.c b/arch/arm64/kernel/kexec_image.c index 9ec34690e255..91e852c735df 100644 --- a/arch/arm64/kernel/kexec_image.c +++ b/arch/arm64/kernel/kexec_image.c @@ -145,3 +145,48 @@ const struct kexec_file_ops kexec_image_ops = { .verify_sig = image_verify_sig, #endif }; + +static int filter_out_reserved_res(struct resource *res, void *arg) +{ + return walk_excluding_child_res(res, arg, + kexec_locate_mem_hole_callback); +} + +/** + * arch_kexec_locate_mem_hole - Find free memory to place the segments. + * @kbuf: Parameters for the memory search. + * + * On success, kbuf->mem will have the start address of the memory region found. + * + * Return: 0 on success, negative errno on error. + */ +int arch_kexec_locate_mem_hole(struct kexec_buf *kbuf) +{ + int ret; + + /* Arch knows where to place */ + if (kbuf->mem != KEXEC_BUF_MEM_UNKNOWN) + return 0; + + /* + * Crash kernels land in a well known place that has been + * reserved upfront. + * + * Normal kexec kernels can however land anywhere in memory. + * We have to be extra careful not to step over critical + * memory ranges that have been marked as reserved in the + * iomem resource tree (LPI and ACPI tables, among others), + * hence the use of the child-excluding iterator. This + * matches what the userspace version of kexec does. + */ + if (kbuf->image->type == KEXEC_TYPE_CRASH) + ret = walk_iomem_res_desc(crashk_res.desc, + IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY, + crashk_res.start, crashk_res.end, + kbuf, kexec_locate_mem_hole_callback); + else + ret = walk_system_ram_res(0, ULONG_MAX, kbuf, + filter_out_reserved_res); + + return ret == 1 ? 0 : -EADDRNOTAVAIL; +} -- 2.30.2 _______________________________________________ kexec mailing list [email protected] http://lists.infradead.org/mailman/listinfo/kexec
