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    x86/mm: simplify init_trampoline() and surrounding logic · 88107d33
    Mike Rapoport 提交于
    There are three cases for the trampoline initialization:
    * 32-bit does nothing
    * 64-bit with kaslr disabled simply copies a PGD entry from the direct map
      to the trampoline PGD
    * 64-bit with kaslr enabled maps the real mode trampoline at PUD level
    
    These cases are currently differentiated by a bunch of ifdefs inside
    asm/include/pgtable.h and the case of 64-bits with kaslr on uses
    pgd_index() helper.
    
    Replacing the ifdefs with a static function in arch/x86/mm/init.c gives
    clearer code and allows moving pgd_index() to the generic implementation
    in include/linux/pgtable.h
    
    [rppt@linux.ibm.com: take CONFIG_RANDOMIZE_MEMORY into account in kaslr_enabled()]
      Link: http://lkml.kernel.org/r/20200525104045.GB13212@linux.ibm.comSigned-off-by: NMike Rapoport <rppt@linux.ibm.com>
    Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
    Cc: Arnd Bergmann <arnd@arndb.de>
    Cc: Borislav Petkov <bp@alien8.de>
    Cc: Brian Cain <bcain@codeaurora.org>
    Cc: Catalin Marinas <catalin.marinas@arm.com>
    Cc: Chris Zankel <chris@zankel.net>
    Cc: "David S. Miller" <davem@davemloft.net>
    Cc: Geert Uytterhoeven <geert@linux-m68k.org>
    Cc: Greentime Hu <green.hu@gmail.com>
    Cc: Greg Ungerer <gerg@linux-m68k.org>
    Cc: Guan Xuetao <gxt@pku.edu.cn>
    Cc: Guo Ren <guoren@kernel.org>
    Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
    Cc: Helge Deller <deller@gmx.de>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Ley Foon Tan <ley.foon.tan@intel.com>
    Cc: Mark Salter <msalter@redhat.com>
    Cc: Matthew Wilcox <willy@infradead.org>
    Cc: Matt Turner <mattst88@gmail.com>
    Cc: Max Filippov <jcmvbkbc@gmail.com>
    Cc: Michael Ellerman <mpe@ellerman.id.au>
    Cc: Michal Simek <monstr@monstr.eu>
    Cc: Nick Hu <nickhu@andestech.com>
    Cc: Paul Walmsley <paul.walmsley@sifive.com>
    Cc: Richard Weinberger <richard@nod.at>
    Cc: Rich Felker <dalias@libc.org>
    Cc: Russell King <linux@armlinux.org.uk>
    Cc: Stafford Horne <shorne@gmail.com>
    Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: Tony Luck <tony.luck@intel.com>
    Cc: Vincent Chen <deanbo422@gmail.com>
    Cc: Vineet Gupta <vgupta@synopsys.com>
    Cc: Will Deacon <will@kernel.org>
    Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
    Link: http://lkml.kernel.org/r/20200514170327.31389-8-rppt@kernel.orgSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
    88107d33
kaslr.c 5.6 KB