From f06bdd4001c257792c54dce9427399f2896470af Mon Sep 17 00:00:00 2001 From: Thomas Garnier Date: Tue, 14 Mar 2017 10:05:06 -0700 Subject: [PATCH] x86/mm: Adapt MODULES_END based on fixmap section size MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This patch aligns MODULES_END to the beginning of the fixmap section. It optimizes the space available for both sections. The address is pre-computed based on the number of pages required by the fixmap section. It will allow GDT remapping in the fixmap section. The current MODULES_END static address does not provide enough space for the kernel to support a large number of processors. Signed-off-by: Thomas Garnier Cc: Alexander Potapenko Cc: Andrew Morton Cc: Andrey Ryabinin Cc: Andy Lutomirski Cc: Ard Biesheuvel Cc: Boris Ostrovsky Cc: Borislav Petkov Cc: Chris Wilson Cc: Christian Borntraeger Cc: Dmitry Vyukov Cc: Frederic Weisbecker Cc: Jiri Kosina Cc: Joerg Roedel Cc: Jonathan Corbet Cc: Josh Poimboeuf Cc: Juergen Gross Cc: Kees Cook Cc: Len Brown Cc: Linus Torvalds Cc: Lorenzo Stoakes Cc: Luis R . Rodriguez Cc: Matt Fleming Cc: Michal Hocko Cc: Paolo Bonzini Cc: Paul Gortmaker Cc: Pavel Machek Cc: Peter Zijlstra Cc: Radim Krčmář Cc: Rafael J . Wysocki Cc: Rusty Russell Cc: Stanislaw Gruszka Cc: Thomas Gleixner Cc: Tim Chen Cc: Vitaly Kuznetsov Cc: kasan-dev@googlegroups.com Cc: kernel-hardening@lists.openwall.com Cc: kvm@vger.kernel.org Cc: lguest@lists.ozlabs.org Cc: linux-doc@vger.kernel.org Cc: linux-efi@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-pm@vger.kernel.org Cc: xen-devel@lists.xenproject.org Cc: zijun_hu Link: http://lkml.kernel.org/r/20170314170508.100882-1-thgarnie@google.com [ Small build fix. ] Signed-off-by: Ingo Molnar --- Documentation/x86/x86_64/mm.txt | 5 ++++- arch/x86/include/asm/pgtable_64_types.h | 3 ++- arch/x86/kernel/module.c | 1 + arch/x86/mm/dump_pagetables.c | 1 + arch/x86/mm/kasan_init_64.c | 1 + mm/vmalloc.c | 4 ++++ 6 files changed, 13 insertions(+), 2 deletions(-) diff --git a/Documentation/x86/x86_64/mm.txt b/Documentation/x86/x86_64/mm.txt index 5724092..ee3f9c30 100644 --- a/Documentation/x86/x86_64/mm.txt +++ b/Documentation/x86/x86_64/mm.txt @@ -19,7 +19,7 @@ ffffff0000000000 - ffffff7fffffffff (=39 bits) %esp fixup stacks ffffffef00000000 - fffffffeffffffff (=64 GB) EFI region mapping space ... unused hole ... ffffffff80000000 - ffffffff9fffffff (=512 MB) kernel text mapping, from phys 0 -ffffffffa0000000 - ffffffffff5fffff (=1526 MB) module mapping space +ffffffffa0000000 - ffffffffff5fffff (=1526 MB) module mapping space (variable) ffffffffff600000 - ffffffffffdfffff (=8 MB) vsyscalls ffffffffffe00000 - ffffffffffffffff (=2 MB) unused hole @@ -39,6 +39,9 @@ memory window (this size is arbitrary, it can be raised later if needed). The mappings are not part of any other kernel PGD and are only available during EFI runtime calls. +The module mapping space size changes based on the CONFIG requirements for the +following fixmap section. + Note that if CONFIG_RANDOMIZE_MEMORY is enabled, the direct mapping of all physical memory, vmalloc/ioremap space and virtual memory map are randomized. Their order is preserved but their base will be offset early at boot time. diff --git a/arch/x86/include/asm/pgtable_64_types.h b/arch/x86/include/asm/pgtable_64_types.h index 0b2797e..516593e6 100644 --- a/arch/x86/include/asm/pgtable_64_types.h +++ b/arch/x86/include/asm/pgtable_64_types.h @@ -68,7 +68,8 @@ typedef struct { pteval_t pte; } pte_t; #endif /* CONFIG_RANDOMIZE_MEMORY */ #define VMALLOC_END (VMALLOC_START + _AC((VMALLOC_SIZE_TB << 40) - 1, UL)) #define MODULES_VADDR (__START_KERNEL_map + KERNEL_IMAGE_SIZE) -#define MODULES_END _AC(0xffffffffff000000, UL) +/* The module sections ends with the start of the fixmap */ +#define MODULES_END __fix_to_virt(__end_of_fixed_addresses + 1) #define MODULES_LEN (MODULES_END - MODULES_VADDR) #define ESPFIX_PGD_ENTRY _AC(-2, UL) #define ESPFIX_BASE_ADDR (ESPFIX_PGD_ENTRY << PGDIR_SHIFT) diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c index 477ae80..fad61ca 100644 --- a/arch/x86/kernel/module.c +++ b/arch/x86/kernel/module.c @@ -35,6 +35,7 @@ #include #include #include +#include #if 0 #define DEBUGP(fmt, ...) \ diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c index 58b5bee..75efeec 100644 --- a/arch/x86/mm/dump_pagetables.c +++ b/arch/x86/mm/dump_pagetables.c @@ -20,6 +20,7 @@ #include #include +#include /* * The dumper groups pagetable entries of the same type into one, and for diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c index 8d63d7a..1bde19e 100644 --- a/arch/x86/mm/kasan_init_64.c +++ b/arch/x86/mm/kasan_init_64.c @@ -9,6 +9,7 @@ #include #include +#include extern pgd_t early_level4_pgt[PTRS_PER_PGD]; extern struct range pfn_mapped[E820_X_MAX]; diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 0dd8022..b7d2a23 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -36,6 +36,10 @@ #include #include +#ifdef CONFIG_X86 +# include +#endif + #include "internal.h" struct vfree_deferred { -- 2.7.4