• Chao Fan's avatar
    x86/boot: Add "acpi_rsdp=" early parsing · 3c98e71b
    Chao Fan authored
    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: default avatarChao Fan <fanc.fnst@cn.fujitsu.com>
    Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
    Cc: bhe@redhat.com
    Cc: caoj.fnst@cn.fujitsu.com
    Cc: "H. Peter Anvin" <hpa@zytor.com>
    Cc: indou.takao@jp.fujitsu.com
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Juergen Gross <jgross@suse.com>
    Cc: kasong@redhat.com
    Cc: Kees Cook <keescook@chromium.org>
    Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
    Cc: msys.mizuma@gmail.com
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: Tom Lendacky <thomas.lendacky@amd.com>
    Cc: x86-ml <x86@kernel.org>
    Link: https://lkml.kernel.org/r/20190123110850.12433-3-fanc.fnst@cn.fujitsu.com