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path: root/arch/powerpc/mm/subpage-prot.c
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2019-05-03powerpc/mm: Move book3s64 specifics in subdirectory mm/book3s64Christophe Leroy
Many files in arch/powerpc/mm are only for book3S64. This patch creates a subdirectory for them. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> [mpe: Update the selftest sym links, shorten new filenames, cleanup some whitespace and formatting in the new files.] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-01powerpc/mm/radix: Fix kernel crash when running subpage protect testAneesh Kumar K.V
This patch fixes the below crash by making sure we touch the subpage protection related structures only if we know they are allocated on the platform. With radix translation we don't allocate hash context at all and trying to access subpage_prot_table results in: Faulting instruction address: 0xc00000000008bdb4 Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Radix MMU=Hash SMP NR_CPUS=2048 NUMA PowerNV .... NIP [c00000000008bdb4] sys_subpage_prot+0x74/0x590 LR [c00000000000b688] system_call+0x5c/0x70 Call Trace: [c00020002c6b7d30] [c00020002c6b7d90] 0xc00020002c6b7d90 (unreliable) [c00020002c6b7e20] [c00000000000b688] system_call+0x5c/0x70 Instruction dump: fb61ffd8 fb81ffe0 fba1ffe8 fbc1fff0 fbe1fff8 f821ff11 e92d1178 f9210068 39200000 e92d0968 ebe90630 e93f03e8 <eb891038> 60000000 3860fffe e9410068 We also move the subpage_prot_table with mmp_sem held to avoid race between two parallel subpage_prot syscall. Fixes: 701101865f5d ("powerpc/mm: Reduce memory usage for mm_context_t for radix") Reported-by: Sachin Sant <sachinp@linux.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Tested-by: Sachin Sant <sachinp@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-21powerc/mm/hash: Reduce hash_mm_context sizeAneesh Kumar K.V
Allocate subpage protect related variables only if we use the feature. This helps in reducing the hash related mm context struct by around 4K Before the patch sizeof(struct hash_mm_context) = 8288 After the patch sizeof(struct hash_mm_context) = 4160 Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-21powerpc/mm: Add helpers for accessing hash translation related variablesAneesh Kumar K.V
We want to switch to allocating them runtime only when hash translation is enabled. Add helpers so that both book3s and nohash can be adapted to upcoming change easily. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-01-03Remove 'type' argument from access_ok() functionLinus Torvalds
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-30powerpc: remove unnecessary inclusion of asm/tlbflush.hChristophe Leroy
asm/tlbflush.h is only needed for: - using functions xxx_flush_tlb_xxx() - using MMU_NO_CONTEXT - including asm-generic/pgtable.h Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-25powerpc: Remove -Wattribute-alias pragmasPaul Burton
With SYSCALL_DEFINEx() disabling -Wattribute-alias generically, there's no need to duplicate that for PowerPC syscalls. This reverts commit 415520373975 ("powerpc: fix build failure by disabling attribute-alias warning in pci_32") and commit 2479bfc9bc60 ("powerpc: Fix build by disabling attribute-alias warning for SYSCALL_DEFINEx"). Signed-off-by: Paul Burton <paul.burton@mips.com> Acked-by: Christophe Leroy <christophe.leroy@c-s.fr> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-06-03powerpc: Fix build by disabling attribute-alias warning for SYSCALL_DEFINExChristophe Leroy
GCC 8.1 emits warnings such as the following. As arch/powerpc code is built with -Werror, this breaks the build with GCC 8.1. In file included from arch/powerpc/kernel/pci_64.c:23: ./include/linux/syscalls.h:233:18: error: 'sys_pciconfig_iobase' alias between functions of incompatible types 'long int(long int, long unsigned int, long unsigned int)' and 'long int(long int, long int, long int)' [-Werror=attribute-alias] asmlinkage long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \ ^~~ ./include/linux/syscalls.h:222:2: note: in expansion of macro '__SYSCALL_DEFINEx' __SYSCALL_DEFINEx(x, sname, __VA_ARGS__) This patch inhibits those warnings. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> [mpe: Trim change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10powerpc/syscalls: Switch trivial cases to SYSCALL_DEFINEAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-21powerpc/mm: Invalidate subpage_prot() system call on radix platformsAnshuman Khandual
Radix enabled platforms don't support subpage_prot() system calls. But at present the system call goes through without an error and fails later on while validating expected subpage accesses. Lets not allow the system call on powerpc radix platforms to begin with to prevent this confusion in user space. Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-07-27powerpc/mm/hash: Free the subpage_prot_table correctlyAneesh Kumar K.V
Fixes: dad6f37c2602e ("powerpc: subpage_protect: Increase the array size to take care of 64TB") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Tested-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-04-19powerpc/mm/radix: Use mm->task_size for boundary checking instead of addr_limitAneesh Kumar K.V
We don't init addr_limit correctly for 32 bit applications. So default to using mm->task_size for boundary condition checking. We use addr_limit to only control free space search. This makes sure that we do the right thing with 32 bit applications. We should consolidate the usage of TASK_SIZE/mm->task_size and mm->context.addr_limit later. This partially reverts commit fbfef9027c2a7ad (powerpc/mm: Switch some TASK_SIZE checks to use mm_context addr_limit). Fixes: fbfef9027c2a ("powerpc/mm: Switch some TASK_SIZE checks to use mm_context addr_limit") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-04-01powerpc/mm: Switch some TASK_SIZE checks to use mm_context addr_limitAneesh Kumar K.V
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-01-25powerpc/mm: Return directly after a failed __copy_from_user() in ↵Markus Elfring
sys_subpage_prot() This function already has multiple exit points, so there's no harm adding another. Although it looks odd to return directly in a function which takes a lock, we've actually just dropped the mmap_sem in this code, so there's really no reason to go via a label. And it means we can drop the unhelpfully named out2 label. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> [mpe: Rewrite change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-12-24Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds
This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15thp: rename split_huge_page_pmd() to split_huge_pmd()Kirill A. Shutemov
We are going to decouple splitting THP PMD from splitting underlying compound page. This patch renames split_huge_page_pmd*() functions to split_huge_pmd*() to reflect the fact that it doesn't imply page splitting, only PMD. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Jerome Marchand <jmarchan@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11arch/powerpc/mm/subpage-prot.c: use walk->vma and walk_page_vma()Naoya Horiguchi
We don't have to use mm_walk->private to pass vma to the callback function because of mm_walk->vma. And walk_page_vma() is useful if we walk over a single vma. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-02-17powerpc/mm: Add new "set" flag argument to pte/pmd update functionAneesh Kumar K.V
pte_update() is a powerpc-ism used to change the bits of a PTE when the access permission is being restricted (a flush is potentially needed). It uses atomic operations on when needed and handles the hash synchronization on hash based processors. It is currently only used to clear PTE bits and so the current implementation doesn't provide a way to also set PTE bits. The new _PAGE_NUMA bit, when set, is actually restricting access so it must use that function too, so this change adds the ability for pte_update() to also set bits. We will use this later to set the _PAGE_NUMA bit. Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-08-14powerpc: Fix a number of sparse warningsAnton Blanchard
Address some of the trivial sparse warnings in arch/powerpc. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-06-21powerpc: split hugepage when using subpage protectionAneesh Kumar K.V
We find all the overlapping vma and mark them such that we don't allocate hugepage in that range. Also we split existing huge page so that the normal page hash can be invalidated and new page faulted in with new protection bits. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-10powerpc/mm: Match variable types to APIJoe MacDonald
sys_subpage_prot() takes an unsigned long for 'addr' then does some stuff with it and the result is stored in a signed int, i, which is eventually used as the size parameter in a copy_from_user call. Update 'i' to be an unsigned long as well and since 'nw' is used in a size_t context which, depending on whether this is 32- or 64-bit may be unsigned int or unsigned long, switch that to a size_t and always be right. Finally, since we're in the neighbourhood, make the same changes to subpage_prot_clear(). Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Joe MacDonald <joe.macdonald@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2009-12-08powerpc/mm: Fix pgtable cache cleanup with CONFIG_PPC_SUBPAGE_PROTDavid Gibson
Commit a0668cdc154e54bf0c85182e0535eea237d53146 cleans up the handling of kmem_caches for allocating various levels of pagetables. Unfortunately, it conflicts badly with CONFIG_PPC_SUBPAGE_PROT, due to the latter's cleverly hidden technique of adding some extra allocation space to the top level page directory to store the extra information it needs. Since that extra allocation really doesn't fit into the cleaned up page directory allocating scheme, this patch alters CONFIG_PPC_SUBPAGE_PROT to instead allocate its struct subpage_prot_table as part of the mm_context_t. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-12-02Revert "powerpc/mm: Fix bug in pagetable cache cleanup with ↵Benjamin Herrenschmidt
CONFIG_PPC_SUBPAGE_PROT" This reverts commit c045256d146800ea1d741a8e9e377dada6b7e195. It breaks build when CONFIG_PPC_SUBPAGE_PROT is not set. I will commit a fixed version separately Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-11-27powerpc/mm: Fix bug in pagetable cache cleanup with CONFIG_PPC_SUBPAGE_PROTDavid Gibson
Commit a0668cdc154e54bf0c85182e0535eea237d53146 cleans up the handling of kmem_caches for allocating various levels of pagetables. Unfortunately, it conflicts badly with CONFIG_PPC_SUBPAGE_PROT, due to the latter's cleverly hidden technique of adding some extra allocation space to the top level page directory to store the extra information it needs. Since that extra allocation really doesn't fit into the cleaned up page directory allocating scheme, this patch alters CONFIG_PPC_SUBPAGE_PROT to instead allocate its struct subpage_prot_table as part of the mm_context_t. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-01-24[POWERPC] Provide a way to protect 4k subpages when using 64k pagesPaul Mackerras
Using 64k pages on 64-bit PowerPC systems makes life difficult for emulators that are trying to emulate an ISA, such as x86, which use a smaller page size, since the emulator can no longer use the MMU and the normal system calls for controlling page protections. Of course, the emulator can emulate the MMU by checking and possibly remapping the address for each memory access in software, but that is pretty slow. This provides a facility for such programs to control the access permissions on individual 4k sub-pages of 64k pages. The idea is that the emulator supplies an array of protection masks to apply to a specified range of virtual addresses. These masks are applied at the level where hardware PTEs are inserted into the hardware page table based on the Linux PTEs, so the Linux PTEs are not affected. Note that this new mechanism does not allow any access that would otherwise be prohibited; it can only prohibit accesses that would otherwise be allowed. This new facility is only available on 64-bit PowerPC and only when the kernel is configured for 64k pages. The masks are supplied using a new subpage_prot system call, which takes a starting virtual address and length, and a pointer to an array of protection masks in memory. The array has a 32-bit word per 64k page to be protected; each 32-bit word consists of 16 2-bit fields, for which 0 allows any access (that is otherwise allowed), 1 prevents write accesses, and 2 or 3 prevent any access. Implicit in this is that the regions of the address space that are protected are switched to use 4k hardware pages rather than 64k hardware pages (on machines with hardware 64k page support). In fact the whole process is switched to use 4k hardware pages when the subpage_prot system call is used, but this could be improved in future to switch only the affected segments. The subpage protection bits are stored in a 3 level tree akin to the page table tree. The top level of this tree is stored in a structure that is appended to the top level of the page table tree, i.e., the pgd array. Since it will often only be 32-bit addresses (below 4GB) that are protected, the pointers to the first four bottom level pages are also stored in this structure (each bottom level page contains the protection bits for 1GB of address space), so the protection bits for addresses below 4GB can be accessed with one fewer loads than those for higher addresses. Signed-off-by: Paul Mackerras <paulus@samba.org>