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arch, mm: restore dependency of __kernel_map_pages() on DEBUG_PAGEALLOC

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The design of DEBUG_PAGEALLOC presumes that __kernel_map_pages() must
never fail.  With this assumption is wouldn't be safe to allow general
usage of this function.

Moreover, some architectures that implement __kernel_map_pages() have this
function guarded by #ifdef DEBUG_PAGEALLOC and some refuse to map/unmap
pages when page allocation debugging is disabled at runtime.

As all the users of __kernel_map_pages() were converted to use
debug_pagealloc_map_pages() it is safe to make it available only when
DEBUG_PAGEALLOC is set.

Link: https://lkml.kernel.org/r/20201109192128.960-4-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Mike Rapoport 2020-12-14 19:10:30 -08:00 committed by Linus Torvalds
parent 2abf962a8d
commit 5d6ad668f3
12 changed files with 26 additions and 26 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
arch/Kconfig
View File

@ -1047,6 +1047,9 @@ config ARCH_WANT_LD_ORPHAN_WARN
config HAVE_ARCH_PFN_VALID
bool
config ARCH_SUPPORTS_DEBUG_PAGEALLOC
bool
source "kernel/gcov/Kconfig"
source "scripts/gcc-plugins/Kconfig"

4
arch/arm64/Kconfig
View File

@ -71,6 +71,7 @@ config ARM64
select ARCH_USE_QUEUED_RWLOCKS
select ARCH_USE_QUEUED_SPINLOCKS
select ARCH_USE_SYM_ANNOTATIONS
select ARCH_SUPPORTS_DEBUG_PAGEALLOC
select ARCH_SUPPORTS_MEMORY_FAILURE
select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
select ARCH_SUPPORTS_ATOMIC_RMW
@ -1028,9 +1029,6 @@ config HOLES_IN_ZONE
source "kernel/Kconfig.hz"
config ARCH_SUPPORTS_DEBUG_PAGEALLOC
def_bool y
config ARCH_SPARSEMEM_ENABLE
def_bool y
select SPARSEMEM_VMEMMAP_ENABLE

8
arch/arm64/mm/pageattr.c
View File

@ -155,7 +155,7 @@ int set_direct_map_invalid_noflush(struct page *page)
.clear_mask = __pgprot(PTE_VALID),
};
if (!rodata_full)
if (!debug_pagealloc_enabled() && !rodata_full)
return 0;
return apply_to_page_range(&init_mm,
@ -170,7 +170,7 @@ int set_direct_map_default_noflush(struct page *page)
.clear_mask = __pgprot(PTE_RDONLY),
};
if (!rodata_full)
if (!debug_pagealloc_enabled() && !rodata_full)
return 0;
return apply_to_page_range(&init_mm,
@ -178,6 +178,7 @@ int set_direct_map_default_noflush(struct page *page)
PAGE_SIZE, change_page_range, &data);
}
#ifdef CONFIG_DEBUG_PAGEALLOC
void __kernel_map_pages(struct page *page, int numpages, int enable)
{
if (!debug_pagealloc_enabled() && !rodata_full)
@ -186,6 +187,7 @@ void __kernel_map_pages(struct page *page, int numpages, int enable)
set_memory_valid((unsigned long)page_address(page), numpages, enable);
}
#ifdef CONFIG_HIBERNATION
/*
* This function is used to determine if a linear map page has been marked as
* not-valid. Walk the page table and check the PTE_VALID bit. This is based
@ -232,3 +234,5 @@ bool kernel_page_present(struct page *page)
ptep = pte_offset_kernel(pmdp, addr);
return pte_valid(READ_ONCE(*ptep));
}
#endif /* CONFIG_HIBERNATION */
#endif /* CONFIG_DEBUG_PAGEALLOC */

5
arch/powerpc/Kconfig
View File

@ -146,6 +146,7 @@ config PPC
select ARCH_MIGHT_HAVE_PC_SERIO
select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
select ARCH_SUPPORTS_ATOMIC_RMW
select ARCH_SUPPORTS_DEBUG_PAGEALLOC if PPC32 || PPC_BOOK3S_64
select ARCH_USE_BUILTIN_BSWAP
select ARCH_USE_CMPXCHG_LOCKREF if PPC64
select ARCH_USE_QUEUED_RWLOCKS if PPC_QUEUED_SPINLOCKS
@ -356,10 +357,6 @@ config PPC_OF_PLATFORM_PCI
depends on PCI
depends on PPC64 # not supported on 32 bits yet
config ARCH_SUPPORTS_DEBUG_PAGEALLOC
depends on PPC32 || PPC_BOOK3S_64
def_bool y
config ARCH_SUPPORTS_UPROBES
def_bool y

4
arch/riscv/Kconfig
View File

@ -14,6 +14,7 @@ config RISCV
def_bool y
select ARCH_CLOCKSOURCE_INIT
select ARCH_SUPPORTS_ATOMIC_RMW
select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
select ARCH_HAS_BINFMT_FLAT
select ARCH_HAS_DEBUG_VM_PGTABLE
select ARCH_HAS_DEBUG_VIRTUAL if MMU
@ -153,9 +154,6 @@ config ARCH_SELECT_MEMORY_MODEL
config ARCH_WANT_GENERAL_HUGETLB
def_bool y
config ARCH_SUPPORTS_DEBUG_PAGEALLOC
def_bool y
config SYS_SUPPORTS_HUGETLBFS
depends on MMU
def_bool y

2
arch/riscv/include/asm/pgtable.h
View File

@ -461,8 +461,6 @@ static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
#define VMALLOC_START 0
#define VMALLOC_END TASK_SIZE
static inline void __kernel_map_pages(struct page *page, int numpages, int enable) {}
#endif /* !CONFIG_MMU */
#define kern_addr_valid(addr) (1) /* FIXME */

2
arch/riscv/mm/pageattr.c
View File

@ -184,6 +184,7 @@ int set_direct_map_default_noflush(struct page *page)
return ret;
}
#ifdef CONFIG_DEBUG_PAGEALLOC
void __kernel_map_pages(struct page *page, int numpages, int enable)
{
if (!debug_pagealloc_enabled())
@ -196,3 +197,4 @@ void __kernel_map_pages(struct page *page, int numpages, int enable)
__set_memory((unsigned long)page_address(page), numpages,
__pgprot(0), __pgprot(_PAGE_PRESENT));
}
#endif

4
arch/s390/Kconfig
View File

@ -35,9 +35,6 @@ config GENERIC_LOCKBREAK
config PGSTE
def_bool y if KVM
config ARCH_SUPPORTS_DEBUG_PAGEALLOC
def_bool y
config AUDIT_ARCH
def_bool y
@ -106,6 +103,7 @@ config S390
select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
select ARCH_STACKWALK
select ARCH_SUPPORTS_ATOMIC_RMW
select ARCH_SUPPORTS_DEBUG_PAGEALLOC
select ARCH_SUPPORTS_NUMA_BALANCING
select ARCH_USE_BUILTIN_BSWAP
select ARCH_USE_CMPXCHG_LOCKREF

4
arch/sparc/Kconfig
View File

@ -88,6 +88,7 @@ config SPARC64
select HAVE_C_RECORDMCOUNT
select HAVE_ARCH_AUDITSYSCALL
select ARCH_SUPPORTS_ATOMIC_RMW
select ARCH_SUPPORTS_DEBUG_PAGEALLOC
select HAVE_NMI
select HAVE_REGS_AND_STACK_ACCESS_API
select ARCH_USE_QUEUED_RWLOCKS
@ -148,9 +149,6 @@ config GENERIC_ISA_DMA
bool
default y if SPARC32
config ARCH_SUPPORTS_DEBUG_PAGEALLOC
def_bool y if SPARC64
config PGTABLE_LEVELS
default 4 if 64BIT
default 3

4
arch/x86/Kconfig
View File

@ -91,6 +91,7 @@ config X86
select ARCH_STACKWALK
select ARCH_SUPPORTS_ACPI
select ARCH_SUPPORTS_ATOMIC_RMW
select ARCH_SUPPORTS_DEBUG_PAGEALLOC
select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
select ARCH_USE_BUILTIN_BSWAP
select ARCH_USE_QUEUED_RWLOCKS
@ -331,9 +332,6 @@ config ZONE_DMA32
config AUDIT_ARCH
def_bool y if X86_64
config ARCH_SUPPORTS_DEBUG_PAGEALLOC
def_bool y
config KASAN_SHADOW_OFFSET
hex
depends on KASAN

2
arch/x86/mm/pat/set_memory.c
View File

@ -2194,6 +2194,7 @@ int set_direct_map_default_noflush(struct page *page)
return __set_pages_p(page, 1);
}
#ifdef CONFIG_DEBUG_PAGEALLOC
void __kernel_map_pages(struct page *page, int numpages, int enable)
{
if (PageHighMem(page))
@ -2239,6 +2240,7 @@ bool kernel_page_present(struct page *page)
return (pte_val(*pte) & _PAGE_PRESENT);
}
#endif /* CONFIG_HIBERNATION */
#endif /* CONFIG_DEBUG_PAGEALLOC */
int __init kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address,
unsigned numpages, unsigned long page_flags)

10
include/linux/mm.h
View File

@ -2931,7 +2931,11 @@ static inline bool debug_pagealloc_enabled_static(void)
return static_branch_unlikely(&_debug_pagealloc_enabled);
}
#if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_ARCH_HAS_SET_DIRECT_MAP)
#ifdef CONFIG_DEBUG_PAGEALLOC
/*
* To support DEBUG_PAGEALLOC architecture must ensure that
* __kernel_map_pages() never fails
*/
extern void __kernel_map_pages(struct page *page, int numpages, int enable);
static inline void debug_pagealloc_map_pages(struct page *page, int numpages)
@ -2949,13 +2953,13 @@ static inline void debug_pagealloc_unmap_pages(struct page *page, int numpages)
#ifdef CONFIG_HIBERNATION
extern bool kernel_page_present(struct page *page);
#endif /* CONFIG_HIBERNATION */
#else /* CONFIG_DEBUG_PAGEALLOC || CONFIG_ARCH_HAS_SET_DIRECT_MAP */
#else /* CONFIG_DEBUG_PAGEALLOC */
static inline void debug_pagealloc_map_pages(struct page *page, int numpages) {}
static inline void debug_pagealloc_unmap_pages(struct page *page, int numpages) {}
#ifdef CONFIG_HIBERNATION
static inline bool kernel_page_present(struct page *page) { return true; }
#endif /* CONFIG_HIBERNATION */
#endif /* CONFIG_DEBUG_PAGEALLOC || CONFIG_ARCH_HAS_SET_DIRECT_MAP */
#endif /* CONFIG_DEBUG_PAGEALLOC */
#ifdef __HAVE_ARCH_GATE_AREA
extern struct vm_area_struct *get_gate_vma(struct mm_struct *mm);