From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: From: Marc Zyngier Subject: [PATCH v2 5/5] arm64: kexec_image: Restore full kexec functionnality Date: Mon, 31 May 2021 10:57:20 +0100 Message-Id: <20210531095720.77469-6-maz@kernel.org> In-Reply-To: <20210531095720.77469-1-maz@kernel.org> References: <20210531095720.77469-1-maz@kernel.org> MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Catalin Marinas , Will Deacon , Ard Biesheuvel , Mark Rutland , James Morse , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Eric Biederman , Bhupesh SHARMA , AKASHI Takahiro , Dave Young , Andrew Morton , Moritz Fischer , kernel-team@android.com 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 Acked-by: Catalin Marinas Reviewed-by: Ard Biesheuvel Signed-off-by: Marc Zyngier --- arch/arm64/kernel/kexec_image.c | 31 +++++++++++++++++++++++++------ 1 file changed, 25 insertions(+), 6 deletions(-) diff --git a/arch/arm64/kernel/kexec_image.c b/arch/arm64/kernel/kexec_image.c index acf9cd251307..2a51a2ebd2b7 100644 --- a/arch/arm64/kernel/kexec_image.c +++ b/arch/arm64/kernel/kexec_image.c @@ -156,12 +156,31 @@ const struct kexec_file_ops kexec_image_ops = { */ 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; + /* - * For the time being, kexec_file_load isn't reliable except - * for crash kernel. Say sorry to the user. + * 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) - return -EADDRNOTAVAIL; - - return kexec_locate_mem_hole(kbuf); + 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_excluding_child_res(0, ULONG_MAX, kbuf, + kexec_locate_mem_hole_callback); + + return ret == 1 ? 0 : -EADDRNOTAVAIL; } -- 2.30.2 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec