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2013-08-22x86 get_unmapped_area: Access mmap_legacy_base through mm_struct memberRadu Caragea
This is the updated version of df54d6fa5427 ("x86 get_unmapped_area(): use proper mmap base for bottom-up direction") that only randomizes the mmap base address once. Signed-off-by: Radu Caragea <sinaelgl@gmail.com> Reported-and-tested-by: Jeff Shorey <shoreyjeff@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michel Lespinasse <walken@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Adrian Sendroiu <molecula2788@gmail.com> Cc: Greg KH <greg@kroah.com> Cc: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-22Revert "x86 get_unmapped_area(): use proper mmap base for bottom-up direction"Linus Torvalds
This reverts commit df54d6fa54275ce59660453e29d1228c2b45a826. The commit isn't necessarily wrong, but because it recalculates the random mmap_base every time, it seems to confuse user memory allocators that expect contiguous mmap allocations even when the mmap address isn't specified. In particular, the MATLAB Java runtime seems to be unhappy. See https://bugzilla.kernel.org/show_bug.cgi?id=60774 So we'll want to apply the random offset only once, and Radu has a patch for that. Revert this older commit in order to apply the other one. Reported-by: Jeff Shorey <shoreyjeff@gmail.com> Cc: Radu Caragea <sinaelgl@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-13x86 get_unmapped_area(): use proper mmap base for bottom-up directionRadu Caragea
When the stack is set to unlimited, the bottomup direction is used for mmap-ings but the mmap_base is not used and thus effectively renders ASLR for mmapings along with PIE useless. Cc: Michel Lespinasse <walken@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Adrian Sendroiu <molecula2788@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-10mm: remove free_area_cacheMichel Lespinasse
Since all architectures have been converted to use vm_unmapped_area(), there is no remaining use for the free_area_cache. Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Howells <dhowells@redhat.com> Cc: Helge Deller <deller@gmx.de> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Richard Henderson <rth@twiddle.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-12-05x86: Fix mmap random address rangeLudwig Nussel
On x86_32 casting the unsigned int result of get_random_int() to long may result in a negative value. On x86_32 the range of mmap_rnd() therefore was -255 to 255. The 32bit mode on x86_64 used 0 to 255 as intended. The bug was introduced by 675a081 ("x86: unify mmap_{32|64}.c") in January 2008. Signed-off-by: Ludwig Nussel <ludwig.nussel@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: harvey.harrison@gmail.com Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/201111152246.pAFMklOB028527@wpaz5.hot.corp.google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-08-06x86-32, amd: Move va_align definition to unbreak 32-bit buildBorislav Petkov
hpa reported that dfb09f9b7ab03fd367740e541a5caf830ed56726 breaks 32-bit builds with the following error message: /home/hpa/kernel/linux-tip.cpu/arch/x86/kernel/cpu/amd.c:437: undefined reference to `va_align' /home/hpa/kernel/linux-tip.cpu/arch/x86/kernel/cpu/amd.c:436: undefined reference to `va_align' This is due to the fact that va_align is a global in a 64-bit only compilation unit. Move it to mmap.c where it is visible to both subarches. Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Link: http://lkml.kernel.org/r/1312633899-1131-1-git-send-email-bp@amd64.org Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2011-08-05x86, amd: Avoid cache aliasing penalties on AMD family 15hBorislav Petkov
This patch provides performance tuning for the "Bulldozer" CPU. With its shared instruction cache there is a chance of generating an excessive number of cache cross-invalidates when running specific workloads on the cores of a compute module. This excessive amount of cross-invalidations can be observed if cache lines backed by shared physical memory alias in bits [14:12] of their virtual addresses, as those bits are used for the index generation. This patch addresses the issue by clearing all the bits in the [14:12] slice of the file mapping's virtual address at generation time, thus forcing those bits the same for all mappings of a single shared library across processes and, in doing so, avoids instruction cache aliases. It also adds the command line option "align_va_addr=(32|64|on|off)" with which virtual address alignment can be enabled for 32-bit or 64-bit x86 individually, or both, or be completely disabled. This change leaves virtual region address allocation on other families and/or vendors unaffected. Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Link: http://lkml.kernel.org/r/1312550110-24160-2-git-send-email-bp@amd64.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-01-27x86: Use helpers for rlimitsJiri Slaby
Make sure compiler won't do weird things with limits. Fetching them twice may return 2 different values after writable limits are implemented. We can either use rlimit helpers added in 3e10e716abf3c71bdb5d86b8f507f9e72236c9cd or ACCESS_ONCE if not applicable; this patch uses the helpers. Signed-off-by: Jiri Slaby <jslaby@suse.cz> LKML-Reference: <1264609942-24621-1-git-send-email-jslaby@suse.cz> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-09-10x86: Increase MIN_GAP to include randomized stackMichal Hocko
Currently we are not including randomized stack size when calculating mmap_base address in arch_pick_mmap_layout for topdown case. This might cause that mmap_base starts in the stack reserved area because stack is randomized by 1GB for 64b (8MB for 32b) and the minimum gap is 128MB. If the stack really grows down to mmap_base then we can get silent mmap region overwrite by the stack values. Let's include maximum stack randomization size into MIN_GAP which is used as the low bound for the gap in mmap. Signed-off-by: Michal Hocko <mhocko@suse.cz> LKML-Reference: <1252400515-6866-1-git-send-email-mhocko@suse.cz> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Stable Team <stable@kernel.org>
2009-01-31x86: update copyrightsIngo Molnar
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-30x86: unify mmap_{32|64}.cHarvey Harrison
mmap_is_ia32 always true for X86_32, or while emulating IA32 on X86_64 Randomization not supported on X86_32 in legacy layout. Both layouts allow randomization on X86_64. Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>