Commit-ID: 3c98e71b42a7d0c14639ccb565ea315f3c887f92 Gitweb: https://git.kernel.org/tip/3c98e71b42a7d0c14639ccb565ea315f3c887f92 Author: Chao Fan <fanc.f...@cn.fujitsu.com> AuthorDate: Wed, 23 Jan 2019 19:08:45 +0800 Committer: Borislav Petkov <b...@suse.de> CommitDate: Fri, 1 Feb 2019 11:52:54 +0100
x86/boot: Add "acpi_rsdp=" early parsing KASLR may randomly choose offsets which are located in movable memory regions resulting in the movable memory becoming immovable. The ACPI SRAT (System/Static Resource Affinity Table) describes memory ranges including ranges of memory provided by hot-added memory devices. In order to access SRAT, one needs the Root System Description Pointer (RSDP) with which to find the Root/Extended System Description Table (R/XSDT) which then contains the system description tables of which SRAT is one of. In case the RSDP address has been passed on the command line (kexec-ing a second kernel) parse it from there. [ bp: Rewrite the commit message and cleanup the code. ] Signed-off-by: Chao Fan <fanc.f...@cn.fujitsu.com> Signed-off-by: Borislav Petkov <b...@suse.de> Cc: b...@redhat.com Cc: caoj.f...@cn.fujitsu.com Cc: "H. Peter Anvin" <h...@zytor.com> Cc: indou.ta...@jp.fujitsu.com Cc: Ingo Molnar <mi...@redhat.com> Cc: Juergen Gross <jgr...@suse.com> Cc: kas...@redhat.com Cc: Kees Cook <keesc...@chromium.org> Cc: "Kirill A. Shutemov" <kirill.shute...@linux.intel.com> Cc: msys.miz...@gmail.com Cc: Thomas Gleixner <t...@linutronix.de> Cc: Tom Lendacky <thomas.lenda...@amd.com> Cc: x86-ml <x...@kernel.org> Link: https://lkml.kernel.org/r/20190123110850.12433-3-fanc.f...@cn.fujitsu.com --- arch/x86/boot/compressed/acpi.c | 32 ++++++++++++++++++++++++++++++++ arch/x86/boot/compressed/misc.h | 3 +++ 2 files changed, 35 insertions(+) diff --git a/arch/x86/boot/compressed/acpi.c b/arch/x86/boot/compressed/acpi.c new file mode 100644 index 000000000000..bacfc4ea35ac --- /dev/null +++ b/arch/x86/boot/compressed/acpi.c @@ -0,0 +1,32 @@ +// SPDX-License-Identifier: GPL-2.0 +#define BOOT_CTYPE_H +#include "misc.h" +#include "error.h" +#include "../string.h" + +#ifdef CONFIG_ACPI + +/* + * Max length of 64-bit hex address string is 19, prefix "0x" + 16 hex + * digits, and '\0' for termination. + */ +#define MAX_ADDR_LEN 19 + +static acpi_physical_address get_acpi_rsdp(void) +{ + acpi_physical_address addr = 0; + +#ifdef CONFIG_KEXEC + char val[MAX_ADDR_LEN] = { }; + int ret; + + ret = cmdline_find_option("acpi_rsdp", val, MAX_ADDR_LEN); + if (ret < 0) + return 0; + + if (kstrtoull(val, 16, &addr)) + return 0; +#endif + return addr; +} +#endif /* CONFIG_ACPI */ diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h index a1d5918765f3..764ad50c0119 100644 --- a/arch/x86/boot/compressed/misc.h +++ b/arch/x86/boot/compressed/misc.h @@ -25,6 +25,9 @@ #include <asm/bootparam.h> #include <asm/bootparam_utils.h> +#define BOOT_CTYPE_H +#include <linux/acpi.h> + #define BOOT_BOOT_H #include "../ctype.h"
