kernel/git/stable/linux.git/arch/powerpc/mm/subpage-prot.c, branch master

powerpc/mm: Move book3s64 specifics in subdirectory mm/book3s64

2019-05-02T15:18:38+00:00

Many files in arch/powerpc/mm are only for book3S64. This patch creates a subdirectory for them. Signed-off-by: Christophe Leroy [mpe: Update the selftest sym links, shorten new filenames, cleanup some whitespace and formatting in the new files.] Signed-off-by: Michael Ellerman

powerpc/mm/radix: Fix kernel crash when running subpage protect test

2019-05-01T13:01:33+00:00

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 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 Signed-off-by: Aneesh Kumar K.V Tested-by: Sachin Sant Signed-off-by: Michael Ellerman

powerc/mm/hash: Reduce hash_mm_context size

2019-04-21T13:12:39+00:00

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 Signed-off-by: Michael Ellerman

powerpc/mm: Add helpers for accessing hash translation related variables

2019-04-21T13:12:38+00:00

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 Signed-off-by: Michael Ellerman

Remove 'type' argument from access_ok() function

2019-01-04T02:57:57+00:00

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

powerpc: remove unnecessary inclusion of asm/tlbflush.h

2018-07-30T12:48:20+00:00

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 Signed-off-by: Michael Ellerman

powerpc: Remove -Wattribute-alias pragmas

2018-06-25T14:21:13+00:00

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 Acked-by: Christophe Leroy Acked-by: Michael Ellerman Signed-off-by: Masahiro Yamada

powerpc: Fix build by disabling attribute-alias warning for SYSCALL_DEFINEx

2018-06-03T10:40:24+00:00

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 [mpe: Trim change log] Signed-off-by: Michael Ellerman

powerpc/syscalls: Switch trivial cases to SYSCALL_DEFINE

2018-05-10T13:25:12+00:00

Signed-off-by: Al Viro Signed-off-by: Michael Ellerman

powerpc/mm: Invalidate subpage_prot() system call on radix platforms

2018-01-20T14:12:21+00:00

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 Signed-off-by: Michael Ellerman