linux/arch/arc/include, branch v4.8

Merge branch 'uaccess-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2016-09-14T16:35:05Z

Pull uaccess fixes from Al Viro: "Fixes for broken uaccess primitives - mostly lack of proper zeroing in copy_from_user()/get_user()/__get_user(), but for several architectures there's more (broken clear_user() on frv and strncpy_from_user() on hexagon)" * 'uaccess-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits) avr32: fix copy_from_user() microblaze: fix __get_user() microblaze: fix copy_from_user() m32r: fix __get_user() blackfin: fix copy_from_user() sparc32: fix copy_from_user() sh: fix copy_from_user() sh64: failing __get_user() should zero score: fix copy_from_user() and friends score: fix __get_user/get_user s390: get_user() should zero on failure ppc32: fix copy_from_user() parisc: fix copy_from_user() openrisc: fix copy_from_user() nios2: fix __get_user() nios2: copy_from_user() should zero the tail of destination mn10300: copy_from_user() should zero on access_ok() failure... mn10300: failing __get_user() and get_user() should zero mips: copy_from_user() must zero the destination on access_ok() failure ARC: uaccess: get_user to zero out dest in cause of fault ...

ARC: uaccess: get_user to zero out dest in cause of fault

2016-09-13T21:49:41Z

Al reported potential issue with ARC get_user() as it wasn't clearing out destination pointer in case of fault due to bad address etc. Verified using following | { | u32 bogus1 = 0xdeadbeef; | u64 bogus2 = 0xdead; | int rc1, rc2; | | pr_info("Orig values %x %llx\n", bogus1, bogus2); | rc1 = get_user(bogus1, (u32 __user *)0x40000000); | rc2 = get_user(bogus2, (u64 __user *)0x50000000); | pr_info("access %d %d, new values %x %llx\n", | rc1, rc2, bogus1, bogus2); | } | [ARCLinux]# insmod /mnt/kernel-module/qtn.ko | Orig values deadbeef dead | access -14 -14, new values 0 0 Reported-by: Al Viro Cc: Linus Torvalds Cc: linux-snps-arc@lists.infradead.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org Signed-off-by: Vineet Gupta Signed-off-by: Al Viro

ARC: mm: fix build breakage with STRICT_MM_TYPECHECKS

2016-08-19T18:04:57Z

| CC mm/memory.o | In file included from ../mm/memory.c:53:0: | ../include/linux/pfn_t.h: In function ‘pfn_t_pte’: | ../include/linux/pfn_t.h:78:2: error: conversion to non-scalar type requested | return pfn_pte(pfn_t_to_pfn(pfn), pgprot); With STRICT_MM_TYPECHECKS pte_t is a struct and the offending code forces a cast which ends up shifting a struct and hence the gcc warning. Note that in recent past some of the arches (aarch64, s390) made STRICT_MM_TYPECHECKS default, but we don't for ARC as this leads to slightly worse generated code, given ARC ABI definition of returning structs (which pte_t would become) Quoting from ARC ABI... "Results of type struct are returned in a caller-supplied temporary variable whose address is passed in r0. For such functions, the arguments are shifted so that they are passed in r1 and up." So - struct to be returned would be allocated on stack requiring extra code at call sites - callee updates stack memory to facilitate the return (vs. simple MOV into return reg r0) Hence STRICT_MM_TYPECHECKS is not enabled by default for ARC Cc: #4.4+ Signed-off-by: Vineet Gupta

ARC: Support syscall ABI v4

2016-08-19T17:44:34Z

The syscall ABI includes the gcc functional calling ABI since a syscall implies userland caller and kernel callee. The current gcc ABI (v3) for ARCv2 ISA required 64-bit data be passed in even-odd register pairs, (potentially punching reg holes when passing such values as args). This was partly driven by the fact that the double-word LDD/STD instructions in ARCv2 expect the register alignment and thus gcc forcing this avoids extra MOV at the cost of a few unused register (which we have plenty anyways). This however was rejected as part of upstreaming gcc port to HS. So the new ABI v4 doesn't enforce the even-odd reg restriction. Do note that for ARCompact ISA builds v3 and v4 are practically the same in terms of gcc code generation. In terms of change management, we infer the new ABI if gcc 6.x onwards is used for building the kernel. This also needs a stable backport to enable older kernels to work with new tools/user-space Cc: Signed-off-by: Vineet Gupta

ARC: use correct offset in pt_regs for saving/restoring user mode r25

2016-08-19T17:44:13Z

User mode callee regs are explicitly collected before signal delivery or breakpoint trap. r25 is special for kernel as it serves as task pointer, so user mode value is clobbered very early. It is saved in pt_regs where generally only scratch (aka caller saved) regs are saved. The code to access the corresponding pt_regs location had a subtle bug as it was using load/store with scaling of offset, whereas the offset was already byte wise correct. So fix this by replacing LD.AS with a standard LD Cc: Signed-off-by: Liav Rehana Reviewed-by: Alexey Brodkin [vgupta: rewrote title and commit log] Signed-off-by: Vineet Gupta

ARC: Call trace_hardirqs_on() before enabling irqs

2016-08-10T17:14:07Z

trace_hardirqs_on_caller() in lockdep.c expects to be called before, not after interrupts are actually enabled. The following comment in kernel/locking/lockdep.c substantiates this claim: " /* * We're enabling irqs and according to our state above irqs weren't * already enabled, yet we find the hardware thinks they are in fact * enabled.. someone messed up their IRQ state tracing. */ " An example can be found in include/linux/irqflags.h: do { trace_hardirqs_on(); raw_local_irq_enable(); } while (0) Without this change, we hit the following DEBUG_LOCKS_WARN_ON. [ 7.760000] ------------[ cut here ]------------ [ 7.760000] WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:2711 resume_user_mode_begin+0x48/0xf0 [ 7.770000] DEBUG_LOCKS_WARN_ON(!irqs_disabled()) [ 7.780000] Modules linked in: [ 7.780000] CPU: 0 PID: 1 Comm: init Not tainted 4.7.0-00003-gc668bb9-dirty #366 [ 7.790000] [ 7.790000] Stack Trace: [ 7.790000] arc_unwind_core.constprop.1+0xa4/0x118 [ 7.800000] warn_slowpath_fmt+0x72/0x158 [ 7.800000] resume_user_mode_begin+0x48/0xf0 [ 7.810000] ---[ end trace 6f6a7a8fae20d2f0 ]--- Signed-off-by: Daniel Mentz Cc: Signed-off-by: Vineet Gupta

Merge tag 'arc-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

2016-07-29T20:17:34Z

Pull ARC updates from Vineet Gupta: "Things have been calm here - nothing much except for a few fixes" * tag 'arc-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: ARC: mm: don't loose PTE_SPECIAL in pte_modify() ARC: dma: fix address translation in arc_dma_free ARC: typo fix in mm/ioremap.c ARC: fix linux-next build breakage

ARC: mm: don't loose PTE_SPECIAL in pte_modify()

2016-07-28T19:38:17Z

LTP madvise05 was generating mm splat | [ARCLinux]# /sd/ltp/testcases/bin/madvise05 | BUG: Bad page map in process madvise05 pte:80e08211 pmd:9f7d4000 | page:9fdcfc90 count:1 mapcount:-1 mapping: (null) index:0x0 flags: 0x404(referenced|reserved) | page dumped because: bad pte | addr:200b8000 vm_flags:00000070 anon_vma: (null) mapping: (null) index:1005c | file: (null) fault: (null) mmap: (null) readpage: (null) | CPU: 2 PID: 6707 Comm: madvise05 And for newer kernels, the system was rendered unusable afterwards. The problem was mprotect->pte_modify() clearing PTE_SPECIAL (which is set to identify the special zero page wired to the pte). When pte was finally unmapped, special casing for zero page was not done, and instead it was treated as a "normal" page, tripping on the map counts etc. This fixes ARC STAR 9001053308 Cc: Signed-off-by: Vineet Gupta

Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-07-25T19:41:29Z

Pull locking updates from Ingo Molnar: "The locking tree was busier in this cycle than the usual pattern - a couple of major projects happened to coincide. The main changes are: - implement the atomic_fetch_{add,sub,and,or,xor}() API natively across all SMP architectures (Peter Zijlstra) - add atomic_fetch_{inc/dec}() as well, using the generic primitives (Davidlohr Bueso) - optimize various aspects of rwsems (Jason Low, Davidlohr Bueso, Waiman Long) - optimize smp_cond_load_acquire() on arm64 and implement LSE based atomic{,64}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}() on arm64 (Will Deacon) - introduce smp_acquire__after_ctrl_dep() and fix various barrier mis-uses and bugs (Peter Zijlstra) - after discovering ancient spin_unlock_wait() barrier bugs in its implementation and usage, strengthen its semantics and update/fix usage sites (Peter Zijlstra) - optimize mutex_trylock() fastpath (Peter Zijlstra) - ... misc fixes and cleanups" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (67 commits) locking/atomic: Introduce inc/dec variants for the atomic_fetch_$op() API locking/barriers, arch/arm64: Implement LDXR+WFE based smp_cond_load_acquire() locking/static_keys: Fix non static symbol Sparse warning locking/qspinlock: Use __this_cpu_dec() instead of full-blown this_cpu_dec() locking/atomic, arch/tile: Fix tilepro build locking/atomic, arch/m68k: Remove comment locking/atomic, arch/arc: Fix build locking/Documentation: Clarify limited control-dependency scope locking/atomic, arch/rwsem: Employ atomic_long_fetch_add() locking/atomic, arch/qrwlock: Employ atomic_fetch_add_acquire() locking/atomic, arch/mips: Convert to _relaxed atomics locking/atomic, arch/alpha: Convert to _relaxed atomics locking/atomic: Remove the deprecated atomic_{set,clear}_mask() functions locking/atomic: Remove linux/atomic.h:atomic_fetch_or() locking/atomic: Implement atomic{,64,_long}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}() locking/atomic: Fix atomic64_relaxed() bits locking/atomic, arch/xtensa: Implement atomic_fetch_{add,sub,and,or,xor}() locking/atomic, arch/x86: Implement atomic{,64}_fetch_{add,sub,and,or,xor}() locking/atomic, arch/tile: Implement atomic{,64}_fetch_{add,sub,and,or,xor}() locking/atomic, arch/sparc: Implement atomic{,64}_fetch_{add,sub,and,or,xor}() ...

arc: get rid of superfluous __GFP_REPEAT

2016-06-25T00:23:52Z

__GFP_REPEAT has a rather weak semantic but since it has been introduced around 2.6.12 it has been ignored for low order allocations. pte_alloc_one_kernel uses __get_order_pte but this is obviously always zero because BITS_FOR_PTE is not larger than 9 yet the page size is always larger than 4K. This means that this flag has never been actually useful here because it has always been used only for PAGE_ALLOC_COSTLY requests. Link: http://lkml.kernel.org/r/1464599699-30131-7-git-send-email-mhocko@kernel.org Signed-off-by: Michal Hocko Acked-by: Vineet Gupta Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds