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2015-04-14mm: move memtest under mmVladimir Murzin2-120/+0
Memtest is a simple feature which fills the memory with a given set of patterns and validates memory contents, if bad memory regions is detected it reserves them via memblock API. Since memblock API is widely used by other architectures this feature can be enabled outside of x86 world. This patch set promotes memtest to live under generic mm umbrella and enables memtest feature for arm/arm64. It was reported that this patch set was useful for tracking down an issue with some errant DMA on an arm64 platform. This patch (of 6): There is nothing platform dependent in the core memtest code, so other platforms might benefit from this feature too. [linux@roeck-us.net: MEMTEST depends on MEMBLOCK] Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14mm: expose arch_mmap_rnd when availableKees Cook1-2/+2
When an architecture fully supports randomizing the ELF load location, a per-arch mmap_rnd() function is used to find a randomized mmap base. In preparation for randomizing the location of ET_DYN binaries separately from mmap, this renames and exports these functions as arch_mmap_rnd(). Additionally introduces CONFIG_ARCH_HAS_ELF_RANDOMIZE for describing this feature on architectures that support it (which is a superset of ARCH_BINFMT_ELF_RANDOMIZE_PIE, since s390 already supports a separated ET_DYN ASLR from mmap ASLR without the ARCH_BINFMT_ELF_RANDOMIZE_PIE logic). Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Hector Marco-Gisbert <hecmargi@upv.es> Cc: Russell King <linux@arm.linux.org.uk> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: "David A. Long" <dave.long@linaro.org> Cc: Andrey Ryabinin <a.ryabinin@samsung.com> Cc: Arun Chandran <achandran@mvista.com> Cc: Yann Droneaud <ydroneaud@opteya.com> Cc: Min-Hua Chen <orca.chen@gmail.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Alex Smith <alex@alex-smith.me.uk> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: Vineeth Vijayan <vvijayan@mvista.com> Cc: Jeff Bailey <jeffbailey@google.com> Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Behan Webster <behanw@converseincode.com> Cc: Ismael Ripoll <iripoll@upv.es> Cc: Jan-Simon Mller <dl9pf@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14x86: standardize mmap_rnd() usageKees Cook1-16/+20
In preparation for splitting out ET_DYN ASLR, this refactors the use of mmap_rnd() to be used similarly to arm, and extracts the checking of PF_RANDOMIZE. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14x86, mm: support huge KVA mappings on x86Toshi Kani1-0/+65
Implement huge KVA mapping interfaces on x86. On x86, MTRRs can override PAT memory types with a 4KB granularity. When using a huge page, MTRRs can override the memory type of the huge page, which may lead a performance penalty. The processor can also behave in an undefined manner if a huge page is mapped to a memory range that MTRRs have mapped with multiple different memory types. Therefore, the mapping code falls back to use a smaller page size toward 4KB when a mapping range is covered by non-WB type of MTRRs. The WB type of MTRRs has no affect on the PAT memory types. pud_set_huge() and pmd_set_huge() call mtrr_type_lookup() to see if a given range is covered by MTRRs. MTRR_TYPE_WRBACK indicates that the range is either covered by WB or not covered and the MTRR default value is set to WB. 0xFF indicates that MTRRs are disabled. HAVE_ARCH_HUGE_VMAP is selected when X86_64 or X86_32 with X86_PAE is set. X86_32 without X86_PAE is not supported since such config can unlikey be benefited from this feature, and there was an issue found in testing. [fengguang.wu@intel.com: ioremap_pud_capable can be static] Signed-off-by: Toshi Kani <toshi.kani@hp.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Robert Elliott <Elliott@hp.com> Signed-off-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14x86, mm: support huge I/O mapping capability I/FToshi Kani1-2/+21
Implement huge I/O mapping capability interfaces for ioremap() on x86. IOREMAP_MAX_ORDER is defined to PUD_SHIFT on x86/64 and PMD_SHIFT on x86/32, which overrides the default value defined in <linux/vmalloc.h>. Signed-off-by: Toshi Kani <toshi.kani@hp.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Robert Elliott <Elliott@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14x86: expose number of page table levels on Kconfig levelKirill A. Shutemov1-7/+7
We would want to use number of page table level to define mm_struct. Let's expose it as CONFIG_PGTABLE_LEVELS. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-13Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds1-2/+9
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fix from Ingo Molnar: "Leftover from 4.0 Fix a local stack variable corruption with certain kdump usage patterns (Dave Young)" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm/numa: Fix kernel stack corruption in numa_init()->numa_clear_kernel_node_hotplug()
2015-04-13Merge branch 'x86-mm-for-linus' of ↵Linus Torvalds5-61/+112
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm changes from Ingo Molnar: "The main changes in this cycle were: - reduce the x86/32 PAE per task PGD allocation overhead from 4K to 0.032k (Fenghua Yu) - early_ioremap/memunmap() usage cleanups (Juergen Gross) - gbpages support cleanups (Luis R Rodriguez) - improve AMD Bulldozer (family 0x15) ASLR I$ aliasing workaround to increase randomization by 3 bits (per bootup) (Hector Marco-Gisbert) - misc fixlets" * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm: Improve AMD Bulldozer ASLR workaround x86/mm/pat: Initialize __cachemode2pte_tbl[] and __pte2cachemode_tbl[] in a bit more readable fashion init.h: Clean up the __setup()/early_param() macros x86/mm: Simplify probe_page_size_mask() x86/mm: Further simplify 1 GB kernel linear mappings handling x86/mm: Use early_param_on_off() for direct_gbpages init.h: Add early_param_on_off() x86/mm: Simplify enabling direct_gbpages x86/mm: Use IS_ENABLED() for direct_gbpages x86/mm: Unexport set_memory_ro() and set_memory_rw() x86/mm, efi: Use early_ioremap() in arch/x86/platform/efi/efi-bgrt.c x86/mm: Use early_memunmap() instead of early_iounmap() x86/mm/pat: Ensure different messages in STRICT_DEVMEM and PAT cases x86/mm: Reduce PAE-mode per task pgd allocation overhead from 4K to 32 bytes
2015-04-07x86/mm/numa: Fix kernel stack corruption in ↵Dave Young1-2/+9
numa_init()->numa_clear_kernel_node_hotplug() I got below kernel panic during kdump test on Thinkpad T420 laptop: [ 0.000000] No NUMA configuration found [ 0.000000] Faking a node at [mem 0x0000000000000000-0x0000000037ba4fff] [ 0.000000] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffff81d21910 ... [ 0.000000] Call Trace: [ 0.000000] [<ffffffff817c2a26>] dump_stack+0x45/0x57 [ 0.000000] [<ffffffff817bc8d2>] panic+0xd0/0x204 [ 0.000000] [<ffffffff81d21910>] ? numa_clear_kernel_node_hotplug+0xe6/0xf2 [ 0.000000] [<ffffffff8107741b>] __stack_chk_fail+0x1b/0x20 [ 0.000000] [<ffffffff81d21910>] numa_clear_kernel_node_hotplug+0xe6/0xf2 [ 0.000000] [<ffffffff81d21e5d>] numa_init+0x1a5/0x520 [ 0.000000] [<ffffffff81d222b1>] x86_numa_init+0x19/0x3d [ 0.000000] [<ffffffff81d22460>] initmem_init+0x9/0xb [ 0.000000] [<ffffffff81d0d00c>] setup_arch+0x94f/0xc82 [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120 [ 0.000000] [<ffffffff817bd0bb>] ? printk+0x55/0x6b [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120 [ 0.000000] [<ffffffff81d05d9b>] start_kernel+0xe8/0x4d6 [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120 [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120 [ 0.000000] [<ffffffff81d055ee>] x86_64_start_reservations+0x2a/0x2c [ 0.000000] [<ffffffff81d05751>] x86_64_start_kernel+0x161/0x184 [ 0.000000] ---[ end Kernel panic - not syncing: stack-protector: Kernel sta This is caused by writing over the end of numa mask bitmap in numa_clear_kernel_node(). numa_clear_kernel_node() tries to set the node id in a mask bitmap, by iterating all reserved regions and assuming that every region has a valid nid. This assumption is not true because there's an exception for some graphic memory quirks. See trim_snb_memory() in arch/x86/kernel/setup.c It is easily to reproduce the bug in the kdump kernel because kdump kernel use pre-reserved memory instead of the whole memory, but kexec pass other reserved memory ranges to 2nd kernel as well. like below in my test: kdump kernel ram 0x2d000000 - 0x37bfffff One of the reserved regions: 0x40000000 - 0x40100000 which includes 0x40004000, a page excluded in trim_snb_memory(). For this memblock reserved region the nid is not set, it is still default value MAX_NUMNODES. later node_set will set bit MAX_NUMNODES thus stack corruption happen. This also happens when booting with mem= kernel commandline during my test. Fixing it by adding a check, do not call node_set in case nid is MAX_NUMNODES. Signed-off-by: Dave Young <dyoung@redhat.com> Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bhe@redhat.com Cc: qiuxishi@huawei.com Link: http://lkml.kernel.org/r/20150407134132.GA23522@dhcp-16-198.nay.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23x86/asm/entry: Change all 'user_mode_vm()' calls to 'user_mode()'Andy Lutomirski1-3/+3
user_mode_vm() and user_mode() are now the same. Change all callers of user_mode_vm() to user_mode(). The next patch will remove the definition of user_mode_vm. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brad Spengler <spender@grsecurity.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/43b1f57f3df70df5a08b0925897c660725015554.1426728647.git.luto@kernel.org [ Merged to a more recent kernel. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23x86/mm/fault: Use TASK_SIZE_MAX in is_prefetch()Andy Lutomirski1-1/+1
This is slightly shorter and slightly faster. It's also more correct: the split between user and kernel addresses is TASK_SIZE_MAX, regardless of ti->flags. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brad Spengler <spender@grsecurity.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/09156b63bad90a327827003c9e53faa82ef4c56e.1426728647.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-05x86/mm/pat: Initialize __cachemode2pte_tbl[] and __pte2cachemode_tbl[] in a ↵Ingo Molnar1-18/+22
bit more readable fashion The initialization of these two arrays is a bit difficult to follow: restructure it optically so that a 2D structure shows which bit in the PTE is set and which not. Also improve on comments a bit. No code or data changed: # arch/x86/mm/init.o: text data bss dec hex filename 4585 424 29776 34785 87e1 init.o.before 4585 424 29776 34785 87e1 init.o.after md5: a82e11ff58bcfd0af3a94662a701f65d init.o.before.asm a82e11ff58bcfd0af3a94662a701f65d init.o.after.asm Reviewed-by: Juergen Gross <jgross@suse.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Jan Beulich <JBeulich@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Toshi Kani <toshi.kani@hp.com> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/20150305082135.GB5969@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-05x86/mm: Simplify probe_page_size_mask()Ingo Molnar1-13/+10
Now that we've simplified the gbpages config space, move the 'page_size_mask' initialization into probe_page_size_mask(), right next to the PSE and PGE enablement lines. Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: JBeulich@suse.com Cc: Jan Beulich <JBeulich@suse.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Lindgren <tony@atomide.com> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: julia.lawall@lip6.fr Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-05x86/mm: Further simplify 1 GB kernel linear mappings handlingIngo Molnar1-6/+1
It's a bit pointless to allow Kconfig configuration for 1GB kernel mappings, it's already hidden behind a 'default y' and CONFIG_EXPERT. Remove this complication and simplify the code by renaming CONFIG_ENABLE_DIRECT_GBPAGES to CONFIG_X86_DIRECT_GBPAGES and document the DEBUG_PAGE_ALLOC and KMEMCHECK quirks. Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: JBeulich@suse.com Cc: Jan Beulich <JBeulich@suse.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Lindgren <tony@atomide.com> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: julia.lawall@lip6.fr Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-05x86/mm: Use early_param_on_off() for direct_gbpagesLuis R. Rodriguez2-15/+2
The enabler / disabler is pretty simple, just use the provided wrappers, this lets us easily relate the variable to the associated Kconfig entry. Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: JBeulich@suse.com Cc: Jan Beulich <JBeulich@suse.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Lindgren <tony@atomide.com> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: julia.lawall@lip6.fr Link: http://lkml.kernel.org/r/1425518654-3403-5-git-send-email-mcgrof@do-not-panic.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-05x86/mm: Simplify enabling direct_gbpagesLuis R. Rodriguez2-10/+9
direct_gbpages can be force enabled as an early parameter but not really have taken effect when DEBUG_PAGEALLOC or KMEMCHECK is enabled. You can also enable direct_gbpages right now if you have an x86_64 architecture but your CPU doesn't really have support for this feature. In both cases PG_LEVEL_1G won't actually be enabled but direct_gbpages is used in other areas under the assumptions that PG_LEVEL_1G was set. Fix this by putting together all requirements which make this feature sensible to enable under, and only enable both finally flipping on PG_LEVEL_1G and leaving PG_LEVEL_1G set when this is true. We only enable this feature then to be possible on sensible builds defined by the new ENABLE_DIRECT_GBPAGES. If the CPU has support for it you can either enable this by using the DIRECT_GBPAGES option or using the early kernel parameter. If a platform had support for this you can always force disable it as well. Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: JBeulich@suse.com Cc: Jan Beulich <JBeulich@suse.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Lindgren <tony@atomide.com> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: julia.lawall@lip6.fr Link: http://lkml.kernel.org/r/1425518654-3403-3-git-send-email-mcgrof@do-not-panic.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-05x86/mm: Use IS_ENABLED() for direct_gbpagesLuis R. Rodriguez1-5/+1
Replace #ifdef eyesore with IS_ENABLED() use. Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: JBeulich@suse.com Cc: Jan Beulich <JBeulich@suse.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Lindgren <tony@atomide.com> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: julia.lawall@lip6.fr Link: http://lkml.kernel.org/r/1425518654-3403-2-git-send-email-mcgrof@do-not-panic.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04Merge tag 'v4.0-rc2' into x86/asm, to refresh the treeIngo Molnar10-41/+286
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-28x86/mm: Unexport set_memory_ro() and set_memory_rw()Daniel Borkmann1-2/+0
This effectively unexports set_memory_ro() and set_memory_rw() functions, and thus reverts: a03352d2c1dc ("x86: export set_memory_ro and set_memory_rw"). They have been introduced for debugging purposes in e1000e, but no module user is in mainline kernel (anymore?) and we explicitly do not want modules to use these functions, as they i.e. protect eBPF (interpreted & JIT'ed) images from malicious modifications or bugs. Outside of eBPF scope, I believe also other set_memory_*() functions should be unexported on x86 for modules. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Bruce Allan <bruce.w.allan@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jesse Brandeburg <jesse.brandeburg@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Link: http://lkml.kernel.org/r/a064393a0a5d319eebde5c761cfd743132d4f213.1425040940.git.daniel@iogearbox.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-24Merge tag 'v4.0-rc1' into x86/mm, to refresh the treeIngo Molnar10-41/+286
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-21Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds2-5/+29
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull misc x86 fixes from Ingo Molnar: "This contains: - EFI fixes - a boot printout fix - ASLR/kASLR fixes - intel microcode driver fixes - other misc fixes Most of the linecount comes from an EFI revert" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm/ASLR: Avoid PAGE_SIZE redefinition for UML subarch x86/microcode/intel: Handle truncated microcode images more robustly x86/microcode/intel: Guard against stack overflow in the loader x86, mm/ASLR: Fix stack randomization on 64-bit systems x86/mm/init: Fix incorrect page size in init_memory_mapping() printks x86/mm/ASLR: Propagate base load address calculation Documentation/x86: Fix path in zero-page.txt x86/apic: Fix the devicetree build in certain configs Revert "efi/libstub: Call get_memory_map() to obtain map and desc sizes" x86/efi: Avoid triple faults during EFI mixed mode calls
2015-02-19Merge branch 'tip-x86-kaslr' of ↵Ingo Molnar1-3/+3
git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp into x86/urgent Pull ASLR and kASLR fixes from Borislav Petkov: - Add a global flag announcing KASLR state so that relevant code can do informed decisions based on its setting. (Jiri Kosina) - Fix a stack randomization entropy decrease bug. (Hector Marco-Gisbert) Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-19x86, mm/ASLR: Fix stack randomization on 64-bit systemsHector Marco-Gisbert1-3/+3
The issue is that the stack for processes is not properly randomized on 64 bit architectures due to an integer overflow. The affected function is randomize_stack_top() in file "fs/binfmt_elf.c": static unsigned long randomize_stack_top(unsigned long stack_top) { unsigned int random_variable = 0; if ((current->flags & PF_RANDOMIZE) && !(current->personality & ADDR_NO_RANDOMIZE)) { random_variable = get_random_int() & STACK_RND_MASK; random_variable <<= PAGE_SHIFT; } return PAGE_ALIGN(stack_top) + random_variable; return PAGE_ALIGN(stack_top) - random_variable; } Note that, it declares the "random_variable" variable as "unsigned int". Since the result of the shifting operation between STACK_RND_MASK (which is 0x3fffff on x86_64, 22 bits) and PAGE_SHIFT (which is 12 on x86_64): random_variable <<= PAGE_SHIFT; then the two leftmost bits are dropped when storing the result in the "random_variable". This variable shall be at least 34 bits long to hold the (22+12) result. These two dropped bits have an impact on the entropy of process stack. Concretely, the total stack entropy is reduced by four: from 2^28 to 2^30 (One fourth of expected entropy). This patch restores back the entropy by correcting the types involved in the operations in the functions randomize_stack_top() and stack_maxrandom_size(). The successful fix can be tested with: $ for i in `seq 1 10`; do cat /proc/self/maps | grep stack; done 7ffeda566000-7ffeda587000 rw-p 00000000 00:00 0 [stack] 7fff5a332000-7fff5a353000 rw-p 00000000 00:00 0 [stack] 7ffcdb7a1000-7ffcdb7c2000 rw-p 00000000 00:00 0 [stack] 7ffd5e2c4000-7ffd5e2e5000 rw-p 00000000 00:00 0 [stack] ... Once corrected, the leading bytes should be between 7ffc and 7fff, rather than always being 7fff. Signed-off-by: Hector Marco-Gisbert <hecmargi@upv.es> Signed-off-by: Ismael Ripoll <iripoll@upv.es> [ Rebased, fixed 80 char bugs, cleaned up commit message, added test example and CVE ] Signed-off-by: Kees Cook <keescook@chromium.org> Cc: <stable@vger.kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Fixes: CVE-2015-1593 Link: http://lkml.kernel.org/r/20150214173350.GA18393@www.outflux.net Signed-off-by: Borislav Petkov <bp@suse.de>
2015-02-19x86/mm/init: Fix incorrect page size in init_memory_mapping() printksDave Hansen1-2/+26
With 32-bit non-PAE kernels, we have 2 page sizes available (at most): 4k and 4M. Enabling PAE replaces that 4M size with a 2M one (which 64-bit systems use too). But, when booting a 32-bit non-PAE kernel, in one of our early-boot printouts, we say: init_memory_mapping: [mem 0x00000000-0x000fffff] [mem 0x00000000-0x000fffff] page 4k init_memory_mapping: [mem 0x37000000-0x373fffff] [mem 0x37000000-0x373fffff] page 2M init_memory_mapping: [mem 0x00100000-0x36ffffff] [mem 0x00100000-0x003fffff] page 4k [mem 0x00400000-0x36ffffff] page 2M init_memory_mapping: [mem 0x37400000-0x377fdfff] [mem 0x37400000-0x377fdfff] page 4k Which is obviously wrong. There is no 2M page available. This is probably because of a badly-named variable: in the map_range code: PG_LEVEL_2M. Instead of renaming all the PG_LEVEL_2M's. This patch just fixes the printout: init_memory_mapping: [mem 0x00000000-0x000fffff] [mem 0x00000000-0x000fffff] page 4k init_memory_mapping: [mem 0x37000000-0x373fffff] [mem 0x37000000-0x373fffff] page 4M init_memory_mapping: [mem 0x00100000-0x36ffffff] [mem 0x00100000-0x003fffff] page 4k [mem 0x00400000-0x36ffffff] page 4M init_memory_mapping: [mem 0x37400000-0x377fdfff] [mem 0x37400000-0x377fdfff] page 4k BRK [0x03206000, 0x03206fff] PGTABLE Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/20150210212030.665EC267@viggo.jf.intel.com Signed-off-by: Borislav Petkov <bp@suse.de>
2015-02-19x86-64: Also clear _PAGE_GLOBAL from __supported_pte_mask if !cpu_has_pgeJan Beulich1-1/+2
Not just setting it when the feature is available is for consistency, and may allow Xen to drop its custom clearing of the flag (unless it needs it cleared earlier than this code executes). Note that the change is benign to ix86, as the flag starts out clear there. Signed-off-by: Jan Beulich <jbeulich@suse.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/54C215D10200007800058912@mail.emea.novell.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-19x86/mm/pat: Ensure different messages in STRICT_DEVMEM and PAT casesPavel Machek1-3/+3
STRICT_DEVMEM and PAT produce same failure accessing /dev/mem, which is quite confusing to the user. Make printk messages different to lessen confusion. Signed-off-by: Pavel Machek <pavel@ucw.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-19x86/mm: Reduce PAE-mode per task pgd allocation overhead from 4K to 32 bytesFenghua Yu1-3/+78
With more embedded systems emerging using Quark, among other things, 32-bit kernel matters again. 32-bit machine and kernel uses PAE paging, which currently wastes at least 4K of memory per process on Linux where we have to reserve an entire page to support a single 32-byte PGD structure. It would be a very good thing if we could eliminate that wastage. PAE paging is used to access more than 4GB memory on x86-32. And it is required for NX. In this patch, we still allocate one page for pgd for a Xen domain and 64-bit kernel because one page pgd is assumed in these cases. But we can save memory space by only allocating 32-byte pgd for 32-bit PAE kernel when it is not running as a Xen domain. Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Christoph Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Glenn Williamson <glenn.p.williamson@intel.com> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1421382601-46912-1-git-send-email-fenghua.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-16Merge branch 'perf-core-for-linus' of ↵Linus Torvalds3-6/+12
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 perf updates from Ingo Molnar: "This series tightens up RDPMC permissions: currently even highly sandboxed x86 execution environments (such as seccomp) have permission to execute RDPMC, which may leak various perf events / PMU state such as timing information and other CPU execution details. This 'all is allowed' RDPMC mode is still preserved as the (non-default) /sys/devices/cpu/rdpmc=2 setting. The new default is that RDPMC access is only allowed if a perf event is mmap-ed (which is needed to correctly interpret RDPMC counter values in any case). As a side effect of these changes CR4 handling is cleaned up in the x86 code and a shadow copy of the CR4 value is added. The extra CR4 manipulation adds ~ <50ns to the context switch cost between rdpmc-capable and rdpmc-non-capable mms" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86: Add /sys/devices/cpu/rdpmc=2 to allow rdpmc for all tasks perf/x86: Only allow rdpmc if a perf_event is mapped perf: Pass the event to arch_perf_update_userpage() perf: Add pmu callbacks to track event mapping and unmapping x86: Add a comment clarifying LDT context switching x86: Store a per-cpu shadow copy of CR4 x86: Clean up cr4 manipulation
2015-02-13kasan: enable instrumentation of global variablesAndrey Ryabinin1-1/+1
This feature let us to detect accesses out of bounds of global variables. This will work as for globals in kernel image, so for globals in modules. Currently this won't work for symbols in user-specified sections (e.g. __init, __read_mostly, ...) The idea of this is simple. Compiler increases each global variable by redzone size and add constructors invoking __asan_register_globals() function. Information about global variable (address, size, size with redzone ...) passed to __asan_register_globals() so we could poison variable's redzone. This patch also forces module_alloc() to return 8*PAGE_SIZE aligned address making shadow memory handling ( kasan_module_alloc()/kasan_module_free() ) more simple. Such alignment guarantees that each shadow page backing modules address space correspond to only one module_alloc() allocation. Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Konstantin Serebryany <kcc@google.com> Cc: Dmitry Chernenkov <dmitryc@google.com> Signed-off-by: Andrey Konovalov <adech.fo@gmail.com> Cc: Yuri Gribov <tetra2005@gmail.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Christoph Lameter <cl@linux.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13kasan: enable stack instrumentationAndrey Ryabinin1-2/+9
Stack instrumentation allows to detect out of bounds memory accesses for variables allocated on stack. Compiler adds redzones around every variable on stack and poisons redzones in function's prologue. Such approach significantly increases stack usage, so all in-kernel stacks size were doubled. Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Konstantin Serebryany <kcc@google.com> Cc: Dmitry Chernenkov <dmitryc@google.com> Signed-off-by: Andrey Konovalov <adech.fo@gmail.com> Cc: Yuri Gribov <tetra2005@gmail.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Christoph Lameter <cl@linux.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13x86_64: add KASan supportAndrey Ryabinin2-0/+202
This patch adds arch specific code for kernel address sanitizer. 16TB of virtual addressed used for shadow memory. It's located in range [ffffec0000000000 - fffffc0000000000] between vmemmap and %esp fixup stacks. At early stage we map whole shadow region with zero page. Latter, after pages mapped to direct mapping address range we unmap zero pages from corresponding shadow (see kasan_map_shadow()) and allocate and map a real shadow memory reusing vmemmap_populate() function. Also replace __pa with __pa_nodebug before shadow initialized. __pa with CONFIG_DEBUG_VIRTUAL=y make external function call (__phys_addr) __phys_addr is instrumented, so __asan_load could be called before shadow area initialized. Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Konstantin Serebryany <kcc@google.com> Cc: Dmitry Chernenkov <dmitryc@google.com> Signed-off-by: Andrey Konovalov <adech.fo@gmail.com> Cc: Yuri Gribov <tetra2005@gmail.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Christoph Lameter <cl@linux.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Jim Davis <jim.epost@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13x86: use %*pb[l] to print bitmaps including cpumasks and nodemasksTejun Heo1-4/+2
printk and friends can now format bitmaps using '%*pb[l]'. cpumask and nodemask also provide cpumask_pr_args() and nodemask_pr_args() respectively which can be used to generate the two printf arguments necessary to format the specified cpu/nodemask. * Unnecessary buffer size calculation and condition on the lenght removed from intel_cacheinfo.c::show_shared_cpu_map_func(). * uv_nmi_nr_cpus_pr() got overly smart and implemented "..." abbreviation if the output stretched over the predefined 1024 byte buffer. Replaced with plain printk. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Mike Travis <travis@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12mm: convert p[te|md]_numa users to p[te|md]_protnone_numaMel Gorman1-2/+2
Convert existing users of pte_numa and friends to the new helper. Note that the kernel is broken after this patch is applied until the other page table modifiers are also altered. This patch layout is to make review easier. Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Sasha Levin <sasha.levin@oracle.com> Cc: Dave Jones <davej@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Rik van Riel <riel@redhat.com> Cc: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11mm: gup: use get_user_pages_unlocked within get_user_pages_fastAndrea Arcangeli1-4/+3
This allows the get_user_pages_fast slow path to release the mmap_sem before blocking. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andres Lagar-Cavilla <andreslc@google.com> Cc: Peter Feiner <pfeiner@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11mm: account pmd page tables to the processKirill A. Shutemov1-5/+9
Dave noticed that unprivileged process can allocate significant amount of memory -- >500 MiB on x86_64 -- and stay unnoticed by oom-killer and memory cgroup. The trick is to allocate a lot of PMD page tables. Linux kernel doesn't account PMD tables to the process, only PTE. The use-cases below use few tricks to allocate a lot of PMD page tables while keeping VmRSS and VmPTE low. oom_score for the process will be 0. #include <errno.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <sys/mman.h> #include <sys/prctl.h> #define PUD_SIZE (1UL << 30) #define PMD_SIZE (1UL << 21) #define NR_PUD 130000 int main(void) { char *addr = NULL; unsigned long i; prctl(PR_SET_THP_DISABLE); for (i = 0; i < NR_PUD ; i++) { addr = mmap(addr + PUD_SIZE, PUD_SIZE, PROT_WRITE|PROT_READ, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0); if (addr == MAP_FAILED) { perror("mmap"); break; } *addr = 'x'; munmap(addr, PMD_SIZE); mmap(addr, PMD_SIZE, PROT_WRITE|PROT_READ, MAP_ANONYMOUS|MAP_PRIVATE|MAP_FIXED, -1, 0); if (addr == MAP_FAILED) perror("re-mmap"), exit(1); } printf("PID %d consumed %lu KiB in PMD page tables\n", getpid(), i * 4096 >> 10); return pause(); } The patch addresses the issue by account PMD tables to the process the same way we account PTE. The main place where PMD tables is accounted is __pmd_alloc() and free_pmd_range(). But there're few corner cases: - HugeTLB can share PMD page tables. The patch handles by accounting the table to all processes who share it. - x86 PAE pre-allocates few PMD tables on fork. - Architectures with FIRST_USER_ADDRESS > 0. We need to adjust sanity check on exit(2). Accounting only happens on configuration where PMD page table's level is present (PMD is not folded). As with nr_ptes we use per-mm counter. The counter value is used to calculate baseline for badness score by oom-killer. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: David Rientjes <rientjes@google.com> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11mm/hugetlb: pmd_huge() returns true for non-present hugepageNaoya Horiguchi2-2/+8
Migrating hugepages and hwpoisoned hugepages are considered as non-present hugepages, and they are referenced via migration entries and hwpoison entries in their page table slots. This behavior causes race condition because pmd_huge() doesn't tell non-huge pages from migrating/hwpoisoned hugepages. follow_page_mask() is one example where the kernel would call follow_page_pte() for such hugepage while this function is supposed to handle only normal pages. To avoid this, this patch makes pmd_huge() return true when pmd_none() is true *and* pmd_present() is false. We don't have to worry about mixing up non-present pmd entry with normal pmd (pointing to leaf level pte entry) because pmd_present() is true in normal pmd. The same race condition could happen in (x86-specific) gup_pmd_range(), where this patch simply adds pmd_present() check instead of pmd_huge(). This is because gup_pmd_range() is fast path. If we have non-present hugepage in this function, we will go into gup_huge_pmd(), then return 0 at flag mask check, and finally fall back to the slow path. Fixes: 290408d4a2 ("hugetlb: hugepage migration core") Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Nishanth Aravamudan <nacc@linux.vnet.ibm.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: <stable@vger.kernel.org> [2.6.36+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11mm/hugetlb: reduce arch dependent code around follow_huge_*Naoya Horiguchi1-12/+0
Currently we have many duplicates in definitions around follow_huge_addr(), follow_huge_pmd(), and follow_huge_pud(), so this patch tries to remove the m. The basic idea is to put the default implementation for these functions in mm/hugetlb.c as weak symbols (regardless of CONFIG_ARCH_WANT_GENERAL_HUGETL B), and to implement arch-specific code only when the arch needs it. For follow_huge_addr(), only powerpc and ia64 have their own implementation, and in all other architectures this function just returns ERR_PTR(-EINVAL). So this patch sets returning ERR_PTR(-EINVAL) as default. As for follow_huge_(pmd|pud)(), if (pmd|pud)_huge() is implemented to always return 0 in your architecture (like in ia64 or sparc,) it's never called (the callsite is optimized away) no matter how implemented it is. So in such architectures, we don't need arch-specific implementation. In some architecture (like mips, s390 and tile,) their current arch-specific follow_huge_(pmd|pud)() are effectively identical with the common code, so this patch lets these architecture use the common code. One exception is metag, where pmd_huge() could return non-zero but it expects follow_huge_pmd() to always return NULL. This means that we need arch-specific implementation which returns NULL. This behavior looks strange to me (because non-zero pmd_huge() implies that the architecture supports PMD-based hugepage, so follow_huge_pmd() can/should return some relevant value,) but that's beyond this cleanup patch, so let's keep it. Justification of non-trivial changes: - in s390, follow_huge_pmd() checks !MACHINE_HAS_HPAGE at first, and this patch removes the check. This is OK because we can assume MACHINE_HAS_HPAGE is true when follow_huge_pmd() can be called (note that pmd_huge() has the same check and always returns 0 for !MACHINE_HAS_HPAGE.) - in s390 and mips, we use HPAGE_MASK instead of PMD_MASK as done in common code. This patch forces these archs use PMD_MASK, but it's OK because they are identical in both archs. In s390, both of HPAGE_SHIFT and PMD_SHIFT are 20. In mips, HPAGE_SHIFT is defined as (PAGE_SHIFT + PAGE_SHIFT - 3) and PMD_SHIFT is define as (PAGE_SHIFT + PAGE_SHIFT + PTE_ORDER - 3), but PTE_ORDER is always 0, so these are identical. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Nishanth Aravamudan <nacc@linux.vnet.ibm.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Steve Capper <steve.capper@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-10Merge branch 'for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial tree changes from Jiri Kosina: "Patches from trivial.git that keep the world turning around. Mostly documentation and comment fixes, and a two corner-case code fixes from Alan Cox" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: kexec, Kconfig: spell "architecture" properly mm: fix cleancache debugfs directory path blackfin: mach-common: ints-priority: remove unused function doubletalk: probe failure causes OOPS ARM: cache-l2x0.c: Make it clear that cache-l2x0 handles L310 cache controller msdos_fs.h: fix 'fields' in comment scsi: aic7xxx: fix comment ARM: l2c: fix comment ibmraid: fix writeable attribute with no store method dynamic_debug: fix comment doc: usbmon: fix spelling s/unpriviledged/unprivileged/ x86: init_mem_mapping(): use capital BIOS in comment
2015-02-10hugetlb, x86: register 1G page size if we can allocate them at runtimeKirill A. Shutemov1-0/+11
After commit 944d9fec8d7a ("hugetlb: add support for gigantic page allocation at runtime") we can allocate 1G pages at runtime if CMA is enabled. Let's register 1G pages into hugetlb even if the user hasn't requested them explicitly at boot time with hugepagesz=1G. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-04x86: Store a per-cpu shadow copy of CR4Andy Lutomirski3-4/+10
Context switches and TLB flushes can change individual bits of CR4. CR4 reads take several cycles, so store a shadow copy of CR4 in a per-cpu variable. To avoid wasting a cache line, I added the CR4 shadow to cpu_tlbstate, which is already touched in switch_mm. The heaviest users of the cr4 shadow will be switch_mm and __switch_to_xtra, and __switch_to_xtra is called shortly after switch_mm during context switch, so the cacheline is likely to be hot. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Kees Cook <keescook@chromium.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Vince Weaver <vince@deater.net> Cc: "hillf.zj" <hillf.zj@alibaba-inc.com> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/3a54dd3353fffbf84804398e00dfdc5b7c1afd7d.1414190806.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-04x86: Clean up cr4 manipulationAndy Lutomirski1-2/+2
CR4 manipulation was split, seemingly at random, between direct (write_cr4) and using a helper (set/clear_in_cr4). Unfortunately, the set_in_cr4 and clear_in_cr4 helpers also poke at the boot code, which only a small subset of users actually wanted. This patch replaces all cr4 access in functions that don't leave cr4 exactly the way they found it with new helpers cr4_set_bits, cr4_clear_bits, and cr4_set_bits_and_update_boot. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Vince Weaver <vince@deater.net> Cc: "hillf.zj" <hillf.zj@alibaba-inc.com> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/495a10bdc9e67016b8fd3945700d46cfd5c12c2f.1414190806.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-01-29vm: add VM_FAULT_SIGSEGV handling supportLinus Torvalds1-0/+2
The core VM already knows about VM_FAULT_SIGBUS, but cannot return a "you should SIGSEGV" error, because the SIGSEGV case was generally handled by the caller - usually the architecture fault handler. That results in lots of duplication - all the architecture fault handlers end up doing very similar "look up vma, check permissions, do retries etc" - but it generally works. However, there are cases where the VM actually wants to SIGSEGV, and applications _expect_ SIGSEGV. In particular, when accessing the stack guard page, libsigsegv expects a SIGSEGV. And it usually got one, because the stack growth is handled by that duplicated architecture fault handler. However, when the generic VM layer started propagating the error return from the stack expansion in commit fee7e49d4514 ("mm: propagate error from stack expansion even for guard page"), that now exposed the existing VM_FAULT_SIGBUS result to user space. And user space really expected SIGSEGV, not SIGBUS. To fix that case, we need to add a VM_FAULT_SIGSEGV, and teach all those duplicate architecture fault handlers about it. They all already have the code to handle SIGSEGV, so it's about just tying that new return value to the existing code, but it's all a bit annoying. This is the mindless minimal patch to do this. A more extensive patch would be to try to gather up the mostly shared fault handling logic into one generic helper routine, and long-term we really should do that cleanup. Just from this patch, you can generally see that most architectures just copied (directly or indirectly) the old x86 way of doing things, but in the meantime that original x86 model has been improved to hold the VM semaphore for shorter times etc and to handle VM_FAULT_RETRY and other "newer" things, so it would be a good idea to bring all those improvements to the generic case and teach other architectures about them too. Reported-and-tested-by: Takashi Iwai <tiwai@suse.de> Tested-by: Jan Engelhardt <jengelh@inai.de> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # "s390 still compiles and boots" Cc: linux-arch@vger.kernel.org Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-01-22x86, mm: Change cachemode exports to non-gplJuergen Gross1-2/+2
Commit 281d4078bec3 ("x86: Make page cache mode a real type") introduced the symbols __cachemode2pte_tbl and __pte2cachemode_tbl and exported them via EXPORT_SYMBOL_GPL. The exports are part of a replacement of code which has been EXPORT_SYMBOL before these changes resulting in build breakage of out-of-tree non-gpl modules. Change EXPORT_SYMBOL_GPL to EXPORT-SYMBOL for these two symbols. Fixes: 281d4078bec3 "x86: Make page cache mode a real type" Reported-and-tested-by: Steven Noonan <steven@uplinklabs.net> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Toshi Kani <toshi.kani@hp.com> Link: http://lkml.kernel.org/r/1421926997-28615-1-git-send-email-jgross@suse.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-01-22x86, mpx: Explicitly disable 32-bit MPX support on 64-bit kernelsDave Hansen1-0/+6
We had originally planned on submitting MPX support in one patch set. We eventually broke it up in to two pieces for easier review. One of the features that didn't make the first round was supporting 32-bit binaries on 64-bit kernels. Once we split the set up, we never added code to restrict 32-bit binaries from _using_ MPX on 64-bit kernels. The 32-bit bounds tables are a different format than the 64-bit ones. Without this patch, the kernel will try to read a 32-bit binary's tables as if they were the 64-bit version. They will likely be noticed as being invalid rather quickly and the app will get killed, but that's kinda mean. This patch adds an explicit check, and will make a 64-bit kernel essentially behave as if it has no MPX support when called from a 32-bit binary. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave@sr71.net> Link: http://lkml.kernel.org/r/20150108223020.9E9AA511@viggo.jf.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-01-20x86: Don't rely on VMWare emulating PAT MSR correctlyJuergen Gross1-1/+6
VMWare seems not to emulate the PAT MSR correctly: reaeding MSR_IA32_CR_PAT returns 0 even after writing another value to it. Commit bd809af16e3ab triggers this VMWare bug when the kernel is booted as a VMWare guest. Detect this bug and don't use the read value if it is 0. Fixes: bd809af16e3ab "x86: Enable PAT to use cache mode translation tables" Reported-and-tested-by: Jongman Heo <jongman.heo@samsung.com> Acked-by: Alok N Kataria <akataria@vmware.com> Signed-off-by: Juergen Gross <jgross@suse.com> Link: http://lkml.kernel.org/r/1421039745-14335-1-git-send-email-jgross@suse.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-01-02x86: init_mem_mapping(): use capital BIOS in commentPavel Machek1-1/+1
Use capital BIOS in comment. Its cleaner, and allows diference between BIOS and BIOs. Signed-off-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-12-23x86: Fix step size adjustment during initial memory mappingJan Beulich1-20/+17
The old scheme can lead to failure in certain cases - the problem is that after bumping step_size the next (non-final) iteration is only guaranteed to make available a memory block the size of what step_size was before. E.g. for a memory block [0,3004600000) we'd have: iter start end step amount 1 3004400000 30045fffff 2M 2M 2 3004000000 30043fffff 64M 4M 3 3000000000 3003ffffff 2G 64M 4 2000000000 2fffffffff 64G 64G Yet to map 64G with 4k pages (as happens e.g. under PV Xen) we need slightly over 128M, but the first three iterations made only about 70M available. The condition (new_mapped_ram_size > mapped_ram_size) for bumping step_size is just not suitable. Instead we want to bump it when we know we have enough memory available to cover a block of the new step_size. And rather than making that condition more complicated than needed, simply adjust step_size by the largest possible factor we know we can cover at that point - which is shifting it left by one less than the difference between page table level shifts. (Interestingly the original STEP_SIZE_SHIFT definition had a comment hinting at that having been the intention, just that it should have been PUD_SHIFT-PMD_SHIFT-1 instead of (PUD_SHIFT-PMD_SHIFT)/2, and of course for non-PAE 32-bit we can't really use these two constants as they're equal there.) Furthermore the comment in get_new_step_size() didn't get updated when the bottom-down mapping logic got added. Yet while an overflow (flushing step_size to zero) of the shift doesn't matter for the top-down method, it does for bottom-up because round_up(x, 0) = 0, and an upper range boundary of zero can't really work well. Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/54945C1E020000780005114E@mail.emea.novell.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-12-20Merge tag 'for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/borntraeger/linux Pull ACCESS_ONCE cleanup preparation from Christian Borntraeger: "kernel: Provide READ_ONCE and ASSIGN_ONCE As discussed on LKML http://marc.info/?i=54611D86.4040306%40de.ibm.com ACCESS_ONCE might fail with specific compilers for non-scalar accesses. Here is a set of patches to tackle that problem. The first patch introduce READ_ONCE and ASSIGN_ONCE. If the data structure is larger than the machine word size memcpy is used and a warning is emitted. The next patches fix up several in-tree users of ACCESS_ONCE on non-scalar types. This does not yet contain a patch that forces ACCESS_ONCE to work only on scalar types. This is targetted for the next merge window as Linux next already contains new offenders regarding ACCESS_ONCE vs. non-scalar types" * tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/borntraeger/linux: s390/kvm: REPLACE barrier fixup with READ_ONCE arm/spinlock: Replace ACCESS_ONCE with READ_ONCE arm64/spinlock: Replace ACCESS_ONCE READ_ONCE mips/gup: Replace ACCESS_ONCE with READ_ONCE x86/gup: Replace ACCESS_ONCE with READ_ONCE x86/spinlock: Replace ACCESS_ONCE with READ_ONCE mm: replace ACCESS_ONCE with READ_ONCE or barriers kernel: Provide READ_ONCE and ASSIGN_ONCE
2014-12-18x86/gup: Replace ACCESS_ONCE with READ_ONCEChristian Borntraeger1-1/+1
ACCESS_ONCE does not work reliably on non-scalar types. For example gcc 4.6 and 4.7 might remove the volatile tag for such accesses during the SRA (scalar replacement of aggregates) step (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145) Change the gup code to replace ACCESS_ONCE with READ_ONCE. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2014-12-17x86: mm: fix VM_FAULT_RETRY handlingLinus Torvalds1-1/+1
My commit 26178ec11ef3 ("x86: mm: consolidate VM_FAULT_RETRY handling") had a really stupid typo: the FAULT_FLAG_USER bit is in the 'flags' variable, not the 'fault' variable. Duh, The one silver lining in this is that Dave finding this at least confirms that trinity actually triggers this special path easily, in a way normal use does not. Reported-by: Dave Jones <davej@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>