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* mips/panic: replace smp_send_stop() with kdump friendly version in panic pathHidehiro Kawai2017-02-234-1/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 54c721b857fd45f3ad3bda695ee4f472518db02a upstream. Daniel Walker reported problems which happens when crash_kexec_post_notifiers kernel option is enabled (https://lkml.org/lkml/2015/6/24/44). In that case, smp_send_stop() is called before entering kdump routines which assume other CPUs are still online. As the result, kdump routines fail to save other CPUs' registers. Additionally for MIPS OCTEON, it misses to stop the watchdog timer. To fix this problem, call a new kdump friendly function, crash_smp_send_stop(), instead of the smp_send_stop() when crash_kexec_post_notifiers is enabled. crash_smp_send_stop() is a weak function, and it just call smp_send_stop(). Architecture codes should override it so that kdump can work appropriately. This patch provides MIPS version. Fixes: f06e5153f4ae (kernel/panic.c: add "crash_kexec_post_notifiers" option) Link: http://lkml.kernel.org/r/20160810080950.11028.28000.stgit@sysi4-13.yrl.intra.hitachi.co.jp Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Reported-by: Daniel Walker <dwalker@fifo99.com> Cc: Dave Young <dyoung@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Daniel Walker <dwalker@fifo99.com> Cc: Xunlei Pang <xpang@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Daney <david.daney@cavium.com> Cc: Aaro Koskinen <aaro.koskinen@iki.fi> Cc: "Steven J. Hill" <steven.hill@cavium.com> Cc: Corey Minyard <cminyard@mvista.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* KVM: MIPS: Drop other CPU ASIDs on guest MMU changesJames Hogan2016-11-201-8/+53
| | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 91e4f1b6073dd680d86cdb7e42d7cccca9db39d8 upstream. When a guest TLB entry is replaced by TLBWI or TLBWR, we only invalidate TLB entries on the local CPU. This doesn't work correctly on an SMP host when the guest is migrated to a different physical CPU, as it could pick up stale TLB mappings from the last time the vCPU ran on that physical CPU. Therefore invalidate both user and kernel host ASIDs on other CPUs, which will cause new ASIDs to be generated when it next runs on those CPUs. We're careful only to do this if the TLB entry was already valid, and only for the kernel ASID where the virtual address it mapped is outside of the guest user address range. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org [james.hogan@imgtec.com: Backport to 3.10..3.16] Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Malta: Fix IOCU disable switch read for MIPS64Paul Burton2016-11-201-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 305723ab439e14debc1d339aa04e835d488b8253 upstream. Malta boards used with CPU emulators feature a switch to disable use of an IOCU. Software has to check this switch & ignore any present IOCU if the switch is closed. The read used to do this was unsafe for 64 bit kernels, as it simply casted the address 0xbf403000 to a pointer & dereferenced it. Whilst in a 32 bit kernel this would access kseg1, in a 64 bit kernel this attempts to access xuseg & results in an address error exception. Fix by accessing a correctly formed ckseg1 address generated using the CKSEG1ADDR macro. Whilst modifying this code, define the name of the register and the bit we care about within it, which indicates whether PCI DMA is routed to the IOCU or straight to DRAM. The code previously checked that bit 0 was also set, but the least significant 7 bits of the CONFIG_GEN0 register contain the value of the MReqInfo signal provided to the IOCU OCP bus, so singling out bit 0 makes little sense & that part of the check is dropped. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Fixes: b6d92b4a6bdb ("MIPS: Add option to disable software I/O coherency.") Cc: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Kees Cook <keescook@chromium.org> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/14187/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* mips: copy_from_user() must zero the destination on access_ok() failureAl Viro2016-11-201-0/+3
| | | | | | | commit e69d700535ac43a18032b3c399c69bf4639e89a2 upstream. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: paravirt: Fix undefined reference to smp_bootstrapMatt Redfearn2016-11-201-0/+2
| | | | | | | | | | | | | | | | | | | | commit 951c39cd3bc0aedf67fbd8fb4b9380287e6205d1 upstream. If the paravirt machine is compiles without CONFIG_SMP, the following linker error occurs arch/mips/kernel/head.o: In function `kernel_entry': (.ref.text+0x10): undefined reference to `smp_bootstrap' due to the kernel entry macro always including SMP startup code. Wrap this code in CONFIG_SMP to fix the error. Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/14212/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: KVM: Check for pfn noslot caseJames Hogan2016-11-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit ba913e4f72fc9cfd03dad968dfb110eb49211d80 upstream. When mapping a page into the guest we error check using is_error_pfn(), however this doesn't detect a value of KVM_PFN_NOSLOT, indicating an error HVA for the page. This can only happen on MIPS right now due to unusual memslot management (e.g. being moved / removed / resized), or with an Enhanced Virtual Memory (EVA) configuration where the default KVM_HVA_ERR_* and kvm_is_error_hva() definitions are unsuitable (fixed in a later patch). This case will be treated as a pfn of zero, mapping the first page of physical memory into the guest. It would appear the MIPS KVM port wasn't updated prior to being merged (in v3.10) to take commit 81c52c56e2b4 ("KVM: do not treat noslot pfn as a error pfn") into account (merged v3.8), which converted a bunch of is_error_pfn() calls to is_error_noslot_pfn(). Switch to using is_error_noslot_pfn() instead to catch this case properly. Fixes: 858dd5d45733 ("KVM/MIPS32: MMU/TLB operations for the Guest.") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [james.hogan@imgtec.com: Backport to v4.7.y] Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.16: adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* gpio: Fix OF build problem on UMLinus Walleij2016-11-201-1/+1
| | | | | | | | | | | | | | commit 2527ecc9195e9c66252af24c4689e8a67cd4ccb9 upstream. The UserMode (UM) Linux build was failing in gpiolib-of as it requires ioremap()/iounmap() to exist, which is absent from UM. The non-existence of IO memory is negatively defined as CONFIG_NO_IOMEM which means we need to depend on HAS_IOMEM. Cc: Geert Uytterhoeven <geert@linux-m68k.org> Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: KVM: Propagate kseg0/mapped tlb fault errorsJames Hogan2016-11-202-14/+37
| | | | | | | | | | | | | | | | | | | | | commit 9b731bcfdec4c159ad2e4312e25d69221709b96a upstream. Propagate errors from kvm_mips_handle_kseg0_tlb_fault() and kvm_mips_handle_mapped_seg_tlb_fault(), usually triggering an internal error since they normally indicate the guest accessed bad physical memory or the commpage in an unexpected way. Fixes: 858dd5d45733 ("KVM/MIPS32: MMU/TLB operations for the Guest.") Fixes: e685c689f3a8 ("KVM/MIPS32: Privileged instruction/target branch emulation.") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> [bwh: Backported to 3.16: adjust filename, context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: KVM: Fix gfn range check in kseg0 tlb faultsJames Hogan2016-11-201-1/+1
| | | | | | | | | | | | | | | | | | commit 0741f52d1b980dbeb290afe67d88fc2928edd8ab upstream. Two consecutive gfns are loaded into host TLB, so ensure the range check isn't off by one if guest_pmap_npages is odd. Fixes: 858dd5d45733 ("KVM/MIPS32: MMU/TLB operations for the Guest.") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> [bwh: Backported to 3.16: adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: KVM: Add missing gfn range checkJames Hogan2016-11-201-8/+15
| | | | | | | | | | | | | | | | | | | | | commit 8985d50382359e5bf118fdbefc859d0dbf6cebc7 upstream. kvm_mips_handle_mapped_seg_tlb_fault() calculates the guest frame number based on the guest TLB EntryLo values, however it is not range checked to ensure it lies within the guest_pmap. If the physical memory the guest refers to is out of range then dump the guest TLB and emit an internal error. Fixes: 858dd5d45733 ("KVM/MIPS32: MMU/TLB operations for the Guest.") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> [bwh: Backported to 3.16: adjust filename, context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: KVM: Fix mapped fault broken commpage handlingJames Hogan2016-11-201-13/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit c604cffa93478f8888bec62b23d6073dad03d43a upstream. kvm_mips_handle_mapped_seg_tlb_fault() appears to map the guest page at virtual address 0 to PFN 0 if the guest has created its own mapping there. The intention is unclear, but it may have been an attempt to protect the zero page from being mapped to anything but the comm page in code paths you wouldn't expect from genuine commpage accesses (guest kernel mode cache instructions on that address, hitting trapping instructions when executing from that address with a coincidental TLB eviction during the KVM handling, and guest user mode accesses to that address). Fix this to check for mappings exactly at KVM_GUEST_COMMPAGE_ADDR (it may not be at address 0 since commit 42aa12e74e91 ("MIPS: KVM: Move commpage so 0x0 is unmapped")), and set the corresponding EntryLo to be interpreted as 0 (invalid). Fixes: 858dd5d45733 ("KVM/MIPS32: MMU/TLB operations for the Guest.") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> [bwh: Backported to 3.16: adjust filename, context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: c-r4k: Fix protected_writeback_scache_line for EVAJames Hogan2016-11-201-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 0758b116b4080d9a2a2a715bec6eee2cbd828215 upstream. The protected_writeback_scache_line() function is used by local_r4k_flush_cache_sigtramp() to flush an FPU delay slot emulation trampoline on the userland stack from the caches so it is visible to subsequent instruction fetches. Commit de8974e3f76c ("MIPS: asm: r4kcache: Add EVA cache flushing functions") updated some protected_ cache flush functions to use EVA CACHEE instructions via protected_cachee_op(), and commit 83fd43449baa ("MIPS: r4kcache: Add EVA case for protected_writeback_dcache_line") did the same thing for protected_writeback_dcache_line(), but protected_writeback_scache_line() never got updated. Lets fix that now to flush the right user address from the secondary cache rather than some arbitrary kernel unmapped address. This issue was spotted through code inspection, and it seems unlikely to be possible to hit this in practice. It theoretically affect EVA kernels on EVA capable cores with an L2 cache, where the icache fetches straight from RAM (cpu_icache_snoops_remote_store == 0), running a hard float userland with FPU disabled (nofpu). That both Malta and Boston platforms override cpu_icache_snoops_remote_store to 1 suggests that all MIPS cores fetch instructions into icache straight from L2 rather than RAM. Fixes: de8974e3f76c ("MIPS: asm: r4kcache: Add EVA cache flushing functions") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13800/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* KEYS: 64-bit MIPS needs to use compat_sys_keyctl for 32-bit userspaceDavid Howells2016-11-202-2/+2
| | | | | | | | | | | | | | | | | | commit 20f06ed9f61a185c6dabd662c310bed6189470df upstream. MIPS64 needs to use compat_sys_keyctl for 32-bit userspace rather than calling sys_keyctl. The latter will work in a lot of cases, thereby hiding the issue. Reported-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: David Howells <dhowells@redhat.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: linux-security-module@vger.kernel.org Cc: keyrings@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13832/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* bpf, mips: fix off-by-one in ctx offset allocationDaniel Borkmann2016-11-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | commit b4e76f7e6d3200462c6354a6ad4ae167459e61f8 upstream. Dan Carpenter reported [1] a static checker warning that ctx->offsets[] may be accessed off by one from build_body(), since it's allocated with fp->len * sizeof(*ctx.offsets) as length. The cBPF arm and ppc code doesn't have this issue as claimed, so only mips seems to be affected and should like most other JITs allocate with fp->len + 1. A few number of JITs (x86, sparc, arm64) handle this differently, where they only require fp->len array elements. [1] http://www.spinics.net/lists/mips/msg64193.html Fixes: c6610de353da ("MIPS: net: Add BPF JIT") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Alexei Starovoitov <ast@kernel.org> Cc: ast@kernel.org Cc: linux-mips@linux-mips.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13814/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: RM7000: Double locking bug in rm7k_tc_disable()Dan Carpenter2016-11-201-1/+1
| | | | | | | | | | | | | | | commit 58a7e1c140f3ad61646bc0cd9a1f6a9cafc0b225 upstream. We obviously intended to enable IRQs again at the end. Fixes: 745aef5df1e2 ('MIPS: RM7000: Add support for tertiary cache') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: kernel-janitors@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13815/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Fix page table corruption on THP permission changes.David Daney2016-11-201-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit acd168c0bf2ce709f056a6b1bf21634b1207d7a5 upstream. When the core THP code is modifying the permissions of a huge page it calls pmd_modify(), which unfortunately was clearing the _PAGE_HUGE bit of the page table entry. The result can be kernel messages like: mm/memory.c:397: bad pmd 000000040080004d. mm/memory.c:397: bad pmd 00000003ff00004d. mm/memory.c:397: bad pmd 000000040100004d. or: ------------[ cut here ]------------ WARNING: at mm/mmap.c:3200 exit_mmap+0x150/0x158() Modules linked in: ipv6 at24 octeon3_ethernet octeon_srio_nexus m25p80 CPU: 12 PID: 1295 Comm: pmderr Not tainted 3.10.87-rt80-Cavium-Octeon #4 Stack : 0000000040808000 0000000014009ce1 0000000000400004 ffffffff81076ba0 0000000000000000 0000000000000000 ffffffff85110000 0000000000000119 0000000000000004 0000000000000000 0000000000000119 43617669756d2d4f 0000000000000000 ffffffff850fda40 ffffffff85110000 0000000000000000 0000000000000000 0000000000000009 ffffffff809207a0 0000000000000c80 ffffffff80f1bf20 0000000000000001 000000ffeca36828 0000000000000001 0000000000000000 0000000000000001 000000ffeca7e700 ffffffff80886924 80000003fd7a0000 80000003fd7a39b0 80000003fdea8000 ffffffff80885780 80000003fdea8000 ffffffff80f12218 000000000000000c 000000000000050f 0000000000000000 ffffffff80865c4c 0000000000000000 0000000000000000 ... Call Trace: [<ffffffff80865c4c>] show_stack+0x6c/0xf8 [<ffffffff80885780>] warn_slowpath_common+0x78/0xa8 [<ffffffff809207a0>] exit_mmap+0x150/0x158 [<ffffffff80882d44>] mmput+0x5c/0x110 [<ffffffff8088b450>] do_exit+0x230/0xa68 [<ffffffff8088be34>] do_group_exit+0x54/0x1d0 [<ffffffff8088bfc0>] __wake_up_parent+0x0/0x18 ---[ end trace c7b38293191c57dc ]--- BUG: Bad rss-counter state mm:80000003fa168000 idx:1 val:1536 Fix by not clearing _PAGE_HUGE bit. Signed-off-by: David Daney <david.daney@cavium.com> Tested-by: Aaro Koskinen <aaro.koskinen@nokia.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13687/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> [bwh: Backported to 3.16: - Adjust context - _PAGE_HUGE might not be defined] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: fix read_msa_* & write_msa_* functions on non-MSA toolchainsPaul Burton2016-08-221-4/+4
| | | | | | | | | | | | | | | | commit 70dff4d90aab40326d1d06a331e2b07eae99d067 upstream. Commit d96cc3d1ec5d "MIPS: Add microMIPS MSA support." attempted to use the value of a macro within an inline asm statement but instead emitted a comment leading to the cfcmsa & ctcmsa instructions being omitted. Fix that by passing CFC_MSA_INSN & CTC_MSA_INSN as arguments to the asm statements. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7305/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: math-emu: Fix jalr emulation when rd == $0Paul Burton2016-08-221-3/+5
| | | | | | | | | | | | | | | | | | | | | | commit ab4a92e66741b35ca12f8497896bafbe579c28a1 upstream. When emulating a jalr instruction with rd == $0, the code in isBranchInstr was incorrectly writing to GPR $0 which should actually always remain zeroed. This would lead to any further instructions emulated which use $0 operating on a bogus value until the task is next context switched, at which point the value of $0 in the task context would be restored to the correct zero by a store in SAVE_SOME. Fix this by not writing to rd if it is $0. Fixes: 102cedc32a6e ("MIPS: microMIPS: Floating point support.") Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Maciej W. Rozycki <macro@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13160/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Fix race condition in lazy cache flushing.Lars Persson2016-08-222-15/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 4d46a67a3eb827ccf1125959936fd51ba318dabc upstream. The lazy cache flushing implemented in the MIPS kernel suffers from a race condition that is exposed by do_set_pte() in mm/memory.c. A pre-condition is a file-system that writes to the page from the CPU in its readpage method and then calls flush_dcache_page(). One example is ubifs. Another pre-condition is that the dcache flush is postponed in __flush_dcache_page(). Upon a page fault for an executable mapping not existing in the page-cache, the following will happen: 1. Write to the page 2. flush_dcache_page 3. flush_icache_page 4. set_pte_at 5. update_mmu_cache (commits the flush of a dcache-dirty page) Between steps 4 and 5 another thread can hit the same page and it will encounter a valid pte. Because the data still is in the L1 dcache the CPU will fetch stale data from L2 into the icache and execute garbage. This fix moves the commit of the cache flush to step 3 to close the race window. It also reduces the amount of flushes on non-executable mappings because we never enter __flush_dcache_page() for non-aliasing CPUs. Regressions can occur in drivers that mistakenly relies on the flush_dcache_page() in get_user_pages() for DMA operations. [ralf@linux-mips.org: Folded in patch 9346 to fix highmem issue.] Signed-off-by: Lars Persson <larper@axis.com> Cc: linux-mips@linux-mips.org Cc: paul.burton@imgtec.com Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/9346/ Patchwork: https://patchwork.linux-mips.org/patch/9738/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: KVM: Fix timer IRQ race when writing CP0_CompareJames Hogan2016-08-223-36/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit b45bacd2d048f405c7760e5cc9b60dd67708734f upstream. Writing CP0_Compare clears the timer interrupt pending bit (CP0_Cause.TI), but this wasn't being done atomically. If a timer interrupt raced with the write of the guest CP0_Compare, the timer interrupt could end up being pending even though the new CP0_Compare is nowhere near CP0_Count. We were already updating the hrtimer expiry with kvm_mips_update_hrtimer(), which used both kvm_mips_freeze_hrtimer() and kvm_mips_resume_hrtimer(). Close the race window by expanding out kvm_mips_update_hrtimer(), and clearing CP0_Cause.TI and setting CP0_Compare between the freeze and resume. Since the pending timer interrupt should not be cleared when CP0_Compare is written via the KVM user API, an ack argument is added to distinguish the source of the write. Fixes: e30492bbe95a ("MIPS: KVM: Rewrite count/compare timer emulation") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [bwh: Backported to 3.16: adjust filenames] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: KVM: Fix timer IRQ race when freezing timerJames Hogan2016-08-221-5/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 4355c44f063d3de4f072d796604c7f4ba4085cc3 upstream. There's a particularly narrow and subtle race condition when the software emulated guest timer is frozen which can allow a guest timer interrupt to be missed. This happens due to the hrtimer expiry being inexact, so very occasionally the freeze time will be after the moment when the emulated CP0_Count transitions to the same value as CP0_Compare (so an IRQ should be generated), but before the moment when the hrtimer is due to expire (so no IRQ is generated). The IRQ won't be generated when the timer is resumed either, since the resume CP0_Count will already match CP0_Compare. With VZ guests in particular this is far more likely to happen, since the soft timer may be frozen frequently in order to restore the timer state to the hardware guest timer. This happens after 5-10 hours of guest soak testing, resulting in an overflow in guest kernel timekeeping calculations, hanging the guest. A more focussed test case to intentionally hit the race (with the help of a new hypcall to cause the timer state to migrated between hardware & software) hits the condition fairly reliably within around 30 seconds. Instead of relying purely on the inexact hrtimer expiry to determine whether an IRQ should be generated, read the guest CP0_Compare and directly check whether the freeze time is before or after it. Only if CP0_Count is on or after CP0_Compare do we check the hrtimer expiry to determine whether the last IRQ has already been generated (which will have pushed back the expiry by one timer period). Fixes: e30492bbe95a ("MIPS: KVM: Rewrite count/compare timer emulation") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [bwh: Backported to 3.16: adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Adjust set_pte() SMP fix to handle R10000_LLSC_WARJoshua Kinard2016-08-221-13/+32
| | | | | | | | | | | | | | | | | | | | | | | | commit 128639395b2ceacc6a56a0141d0261012bfe04d3 upstream. Update the recent changes to set_pte() that were added in 46011e6ea392 to handle R10000_LLSC_WAR, and format the assembly to match other areas of the MIPS tree using the same WAR. This also incorporates a patch recently sent in my Markos Chandras, "Remove local LL/SC preprocessor variants", so that patch doesn't need to be applied if this one is accepted. Signed-off-by: Joshua Kinard <kumba@gentoo.org> Fixes: 46011e6ea392 ("MIPS: Make set_pte() SMP safe.) Cc: David Daney <david.daney@cavium.com> Cc: Linux/MIPS <linux-mips@linux-mips.org> Patchwork: https://patchwork.linux-mips.org/patch/11103/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> [bwh: Backported to 3.2: - Use {LL,SC}_INSN not __{LL,SC} - Use literal arch=r4000 instead of MIPS_ISA_ARCH_LEVEL since R6 is not supported] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Avoid using unwind_stack() with usermodeJames Hogan2016-08-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | commit 81a76d7119f63c359750e4adeff922a31ad1135f upstream. When showing backtraces in response to traps, for example crashes and address errors (usually unaligned accesses) when they are set in debugfs to be reported, unwind_stack will be used if the PC was in the kernel text address range. However since EVA it is possible for user and kernel address ranges to overlap, and even without EVA userland can still trigger an address error by jumping to a KSeg0 address. Adjust the check to also ensure that it was running in kernel mode. I don't believe any harm can come of this problem, since unwind_stack() is sufficiently defensive, however it is only meant for unwinding kernel code, so to be correct it should use the raw backtracing instead. Signed-off-by: James Hogan <james.hogan@imgtec.com> Reviewed-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/11701/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> (cherry picked from commit d2941a975ac745c607dfb590e92bb30bc352dad9) Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Don't unwind to user mode with EVAJames Hogan2016-08-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit a816b306c62195b7c43c92cb13330821a96bdc27 upstream. When unwinding through IRQs and exceptions, the unwinding only continues if the PC is a kernel text address, however since EVA it is possible for user and kernel address ranges to overlap, potentially allowing unwinding to continue to user mode if the user PC happens to be in the kernel text address range. Adjust the check to also ensure that the register state from before the exception is actually running in kernel mode, i.e. !user_mode(regs). I don't believe any harm can come of this problem, since the PC is only output, the stack pointer is checked to ensure it resides within the task's stack page before it is dereferenced in search of the return address, and the return address register is similarly only output (if the PC is in a leaf function or the beginning of a non-leaf function). However unwind_stack() is only meant for unwinding kernel code, so to be correct the unwind should stop there. Signed-off-by: James Hogan <james.hogan@imgtec.com> Reviewed-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/11700/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: BMIPS: Fix PRID_IMP_BMIPS5000 masking for BMIPS5200Florian Fainelli2016-08-221-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | commit cbbda6e7c9c3e4532bd70a73ff9d5e6655c894dc upstream. BMIPS5000 have a PrID value of 0x5A00 and BMIPS5200 have a PrID value of 0x5B00, which, masked with 0x5A00, returns 0x5A00. Update all conditionals on the PrID to cover both variants since we are going to need this to enable BMIPS5200 SMP. The existing check, masking with 0xFF00 would not cover BMIPS5200 at all. Fixes: 68e6a78373a6d ("MIPS: BMIPS: Add PRId for BMIPS5200 (Whirlwind)") Fixes: 6465460c92a85 ("MIPS: BMIPS: change compile time checks to runtime checks") Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Cc: john@phrozen.org Cc: cernekee@gmail.com Cc: jogo@openwrt.org Cc: jaedon.shin@gmail.com Cc: jfraser@broadcom.com Cc: pgynther@google.com Cc: dragan.stancevic@gmail.com Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/12279/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Fix siginfo.h to use strict posix typesJames Hogan2016-08-221-9/+9
| | | | | | | | | | | | | | | | | | | | | | commit 5daebc477da4dfeb31ae193d83084def58fd2697 upstream. Commit 85efde6f4e0d ("make exported headers use strict posix types") changed the asm-generic siginfo.h to use the __kernel_* types, and commit 3a471cbc081b ("remove __KERNEL_STRICT_NAMES") make the internal types accessible only to the kernel, but the MIPS implementation hasn't been updated to match. Switch to proper types now so that the exported asm/siginfo.h won't produce quite so many compiler errors when included alone by a user program. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Christopher Ferris <cferris@google.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/12477/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: ath79: make bootconsole wait for both THRE and TEMTMatthias Schiffer2016-08-221-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | commit f5b556c94c8490d42fea79d7b4ae0ecbc291e69d upstream. This makes the ath79 bootconsole behave the same way as the generic 8250 bootconsole. Also waiting for TEMT (transmit buffer is empty) instead of just THRE (transmit buffer is not full) ensures that all characters have been transmitted before the real serial driver starts reconfiguring the serial controller (which would sometimes result in garbage being transmitted.) This change does not cause a visible performance loss. In addition, this seems to fix a hang observed in certain configurations on many AR7xxx/AR9xxx SoCs during autoconfig of the real serial driver. A more complete follow-up patch will disable 8250 autoconfig for ath79 altogether (the serial controller is detected as a 16550A, which is not fully compatible with the ath79 serial, and the autoconfig may lead to undefined behavior on ath79.) Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: traps: Fix SIGFPE information leak from `do_ov' and `do_trap_or_bp'Maciej W. Rozycki2016-03-241-7/+6
| | | | | | | | | | | | commit e723e3f7f9591b79e8c56b3d7c5a204a9c571b55 upstream. Avoid sending a partially initialised `siginfo_t' structure along SIGFPE signals issued from `do_ov' and `do_trap_or_bp', leading to information leaking from the kernel stack. Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
* MIPS: Fix buffer overflow in syscall_get_arguments()James Hogan2016-02-251-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit f4dce1ffd2e30fa31756876ef502ce6d2324be35 upstream. Since commit 4c21b8fd8f14 ("MIPS: seccomp: Handle indirect system calls (o32)"), syscall_get_arguments() attempts to handle o32 indirect syscall arguments by incrementing both the start argument number and the number of arguments to fetch. However only the start argument number needs to be incremented. The number of arguments does not change, they're just shifted up by one, and in fact the output array is provided by the caller and is likely only n entries long, so reading more arguments overflows the output buffer. In the case of seccomp, this results in it fetching 7 arguments starting at the 2nd one, which overflows the unsigned long args[6] in populate_seccomp_data(). This clobbers the $s0 register from syscall_trace_enter() which __seccomp_phase1_filter() saved onto the stack, into which syscall_trace_enter() had placed its syscall number argument. This caused Chromium to crash. Credit goes to Milko for tracking it down as far as $s0 being clobbered. Fixes: 4c21b8fd8f14 ("MIPS: seccomp: Handle indirect system calls (o32)") Reported-by: Milko Leporis <milko.leporis@imgtec.com> Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/12213/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
* net: filter: make JITs zero A for SKF_AD_ALU_XOR_XRabin Vincent2016-01-251-15/+1
| | | | | | | | | | | | | | | | | | | | | | commit 55795ef5469290f89f04e12e662ded604909e462 upstream. The SKF_AD_ALU_XOR_X ancillary is not like the other ancillary data instructions since it XORs A with X while all the others replace A with some loaded value. All the BPF JITs fail to clear A if this is used as the first instruction in a filter. This was found using american fuzzy lop. Add a helper to determine if A needs to be cleared given the first instruction in a filter, and use this in the JITs. Except for ARM, the rest have only been compile-tested. Fixes: 3480593131e0 ("net: filter: get rid of BPF_S_* enum") Signed-off-by: Rabin Vincent <rabin@rab.in> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> [ luis: backported to 3.16: adjusted context ] Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
* MIPS: uaccess: Fix strlen_user with EVAJames Hogan2016-01-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 5dc62fdd8383afbd2faca6b6e6ea1052b45b0124 upstream. The strlen_user() function calls __strlen_kernel_asm in both branches of the eva_kernel_access() conditional. For EVA it should be calling __strlen_user_eva for user accesses, otherwise it will load from the kernel address space instead of the user address space, and the access checking will likely be ineffective at preventing it due to EVA's overlapping user and kernel address spaces. This was found after extending the test_user_copy module to cover user string access functions, which gave the following error with EVA: test_user_copy: illegal strlen_user passed Fortunately the use of strlen_user() has been all but eradicated from the mainline kernel, so only out of tree modules could be affected. Fixes: e3a9b07a9caf ("MIPS: asm: uaccess: Add EVA support for str*_user operations") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10842/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
* MIPS: uaccess: Take EVA into account in [__]clear_userJames Hogan2016-01-253-10/+26
| | | | | | | | | | | | | | | | | | | | | | | commit d6a428fb583738ad685c91a684748cdee7b2a05f upstream. __clear_user() (and clear_user() which uses it), always access the user mode address space, which results in EVA store instructions when EVA is enabled even if the current user address limit is KERNEL_DS. Fix this by adding a new symbol __bzero_kernel for the normal kernel address space bzero in EVA mode, and call that from __clear_user() if eva_kernel_access(). Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10844/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> [james.hogan@imgtec.com: backport] Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
* MIPS: uaccess: Take EVA into account in __copy_from_user()James Hogan2016-01-251-3/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 6f06a2c45d8d714ea3b11a360b4a7191e52acaa4 upstream. When EVA is in use, __copy_from_user() was unconditionally using the EVA instructions to read the user address space, however this can also be used for kernel access. If the address isn't a valid user address it will cause an address error or TLB exception, and if it is then user memory may be read instead of kernel memory. For example in the following stack trace from Linux v3.10 (changes since then will prevent this particular one still happening) kernel_sendmsg() set the user address limit to KERNEL_DS, and tcp_sendmsg() goes on to use __copy_from_user() with a kernel address in KSeg0. [<8002d434>] __copy_fromuser_common+0x10c/0x254 [<805710e0>] tcp_sendmsg+0x5f4/0xf00 [<804e8e3c>] sock_sendmsg+0x78/0xa0 [<804e8f28>] kernel_sendmsg+0x24/0x38 [<804ee0f8>] sock_no_sendpage+0x70/0x7c [<8017c820>] pipe_to_sendpage+0x80/0x98 [<8017c6b0>] splice_from_pipe_feed+0xa8/0x198 [<8017cc54>] __splice_from_pipe+0x4c/0x8c [<8017e844>] splice_from_pipe+0x58/0x78 [<8017e884>] generic_splice_sendpage+0x20/0x2c [<8017d690>] do_splice_from+0xb4/0x110 [<8017d710>] direct_splice_actor+0x24/0x30 [<8017d394>] splice_direct_to_actor+0xd8/0x208 [<8017d51c>] do_splice_direct+0x58/0x7c [<8014eaf4>] do_sendfile+0x1dc/0x39c [<8014f82c>] SyS_sendfile+0x90/0xf8 Add the eva_kernel_access() check in __copy_from_user() like the one in copy_from_user(). Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10843/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> [james.hogan@imgtec.com: backport] Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
* MIPS: KVM: Uninit VCPU in vcpu_create error pathJames Hogan2015-12-181-1/+4
| | | | | | | | | | | | | | | | | | | | commit 585bb8f9a5e592f2ce7abbe5ed3112d5438d2754 upstream. If either of the memory allocations in kvm_arch_vcpu_create() fail, the vcpu which has been allocated and kvm_vcpu_init'd doesn't get uninit'd in the error handling path. Add a call to kvm_vcpu_uninit() to fix this. Fixes: 669e846e6c4e ("KVM/MIPS32: MIPS arch specific APIs for KVM") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [ luis: backported to 3.16: - file rename: mips.c -> kvm_mips.c ] Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
* MIPS: KVM: Fix CACHE immediate offset sign extensionJames Hogan2015-12-181-1/+1
| | | | | | | | | | | | | | | | | | | | commit c5c2a3b998f1ff5a586f9d37e154070b8d550d17 upstream. The immediate field of the CACHE instruction is signed, so ensure that it gets sign extended by casting it to an int16_t rather than just masking the low 16 bits. Fixes: e685c689f3a8 ("KVM/MIPS32: Privileged instruction/target branch emulation.") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [ luis: backported to 3.16: - file rename: emulate.c -> kvm_mips_emul.c ] Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
* MIPS: KVM: Fix ASID restoration logicJames Hogan2015-12-181-6/+10
| | | | | | | | | | | | | | | | | | | | | | | | | commit 002374f371bd02df864cce1fe85d90dc5b292837 upstream. ASID restoration on guest resume should determine the guest execution mode based on the guest Status register rather than bit 30 of the guest PC. Fix the two places in locore.S that do this, loading the guest status from the cop0 area. Note, this assembly is specific to the trap & emulate implementation of KVM, so it doesn't need to check the supervisor bit as that mode is not implemented in the guest. Fixes: b680f70fc111 ("KVM/MIPS32: Entry point for trampolining to...") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [ luis: backported to 3.16: - file rename: locore.S -> kvm_locore.S ] Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
* MIPS: atomic: Fix comment describing atomic64_add_unless's return value.Ralf Baechle2015-12-131-1/+1
| | | | | | | | | commit f25319d2cb439249a6859f53ad42ffa332b0acba upstream. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Fixes: f24219b4e90cf70ec4a211b17fbabc725a0ddf3c (cherry picked from commit f0a232cde7be18a207fd057dd79bbac8a0a45dec) Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
* MIPS: CPS: #ifdef on CONFIG_MIPS_MT_SMP rather than CONFIG_MIPS_MTPaul Burton2015-10-281-4/+4
| | | | | | | | | | | | | | | | | | | commit 7a63076d9a31a6c2073da45021eeb4f89d2a8b56 upstream. The CONFIG_MIPS_MT symbol can be selected by CONFIG_MIPS_VPE_LOADER in addition to CONFIG_MIPS_MT_SMP. We only want MT code in the CPS SMP boot vector if we're using MT for SMP. Thus switch the config symbol we ifdef against to CONFIG_MIPS_MT_SMP. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/10867/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> [ luis: backported to 3.16: adjusted context ] Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
* MIPS: CPS: Don't include MT code in non-MT kernels.Paul Burton2015-10-281-0/+2
| | | | | | | | | | | | | | | | | | | | commit a5b0f6db0e6cf6224e50f6585e9c8f0c2d38a8f8 upstream. The MT-specific code in mips_cps_boot_vpes can safely be omitted from kernels which don't support MT, with the default VPE==0 case being used as it would be after the has_mt (Config3.MT) check failed at runtime. Discarding the code entirely will save us a few bytes & allow cleaner handling of MT ASE instructions by later patches. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/10866/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> [ luis: backported to 3.16: adjusted context ] Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
* MIPS: CPS: Stop dangling delay slot from has_mt.Paul Burton2015-10-281-2/+2
| | | | | | | | | | | | | | | | | | | | commit 1e5fb282f8eda889776ee83f9214d5df9edaa26d upstream. The has_mt macro ended with a branch, leaving its callers with a delay slot that would be executed if Config3.MT is not set. However it would not be executed if Config3 (or earlier Config registers) don't exist which makes it somewhat inconsistent at best. Fill the delay slot in the macro & fix the mips_cps_boot_vpes caller appropriately. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/10865/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> [ luis: backported to 3.16: adjusted context ] Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
* MIPS: dma-default: Fix 32-bit fall back to GFP_DMAJames Hogan2015-10-281-1/+1
| | | | | | | | | | | | | | | | | | | | | commit 53960059d56ecef67d4ddd546731623641a3d2d1 upstream. If there is a DMA zone (usually 24bit = 16MB I believe), but no DMA32 zone, as is the case for some 32-bit kernels, then massage_gfp_flags() will cause DMA memory allocated for devices with a 32..63-bit coherent_dma_mask to fall back to using __GFP_DMA, even though there may only be 32-bits of physical address available anyway. Correct that case to compare against a mask the size of phys_addr_t instead of always using a 64-bit mask. Signed-off-by: James Hogan <james.hogan@imgtec.com> Fixes: a2e715a86c6d ("MIPS: DMA: Fix computation of DMA flags from device's coherent_dma_mask.") Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9610/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
* signal: fix information leak in copy_siginfo_from_user32Amanieu d'Antras2015-09-031-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 3c00cb5e68dc719f2fc73a33b1b230aadfcb1309 upstream. This function can leak kernel stack data when the user siginfo_t has a positive si_code value. The top 16 bits of si_code descibe which fields in the siginfo_t union are active, but they are treated inconsistently between copy_siginfo_from_user32, copy_siginfo_to_user32 and copy_siginfo_to_user. copy_siginfo_from_user32 is called from rt_sigqueueinfo and rt_tgsigqueueinfo in which the user has full control overthe top 16 bits of si_code. This fixes the following information leaks: x86: 8 bytes leaked when sending a signal from a 32-bit process to itself. This leak grows to 16 bytes if the process uses x32. (si_code = __SI_CHLD) x86: 100 bytes leaked when sending a signal from a 32-bit process to a 64-bit process. (si_code = -1) sparc: 4 bytes leaked when sending a signal from a 32-bit process to a 64-bit process. (si_code = any) parsic and s390 have similar bugs, but they are not vulnerable because rt_[tg]sigqueueinfo have checks that prevent sending a positive si_code to a different process. These bugs are also fixed for consistency. Signed-off-by: Amanieu d'Antras <amanieu@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
* MIPS: Fix seccomp syscall argument for MIPS64Markos Chandras2015-09-032-2/+2
| | | | | | | | | | | | | | | | | | | commit 9f161439e4104b641a7bfb9b89581d801159fec8 upstream. Commit 4c21b8fd8f14 ("MIPS: seccomp: Handle indirect system calls (o32)") fixed indirect system calls on O32 but it also introduced a bug for MIPS64 where it erroneously modified the v0 (syscall) register with the assumption that the sycall offset hasn't been taken into consideration. This breaks seccomp on MIPS64 n64 and n32 ABIs. We fix this by replacing the addition with a move instruction. Fixes: 4c21b8fd8f14 ("MIPS: seccomp: Handle indirect system calls (o32)") Reviewed-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10951/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
* MIPS: Make set_pte() SMP safe.David Daney2015-08-271-0/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | commit 46011e6ea39235e4aca656673c500eac81a07a17 upstream. On MIPS the GLOBAL bit of the PTE must have the same value in any aligned pair of PTEs. These pairs of PTEs are referred to as "buddies". In a SMP system is is possible for two CPUs to be calling set_pte() on adjacent PTEs at the same time. There is a race between setting the PTE and a different CPU setting the GLOBAL bit in its buddy PTE. This race can be observed when multiple CPUs are executing vmap()/vfree() at the same time. Make setting the buddy PTE's GLOBAL bit an atomic operation to close the race condition. The case of CONFIG_64BIT_PHYS_ADDR && CONFIG_CPU_MIPS32 is *not* handled. Signed-off-by: David Daney <david.daney@cavium.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10835/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
* MIPS: Flush RPS on kernel entry with EVAJames Hogan2015-08-271-0/+25
| | | | | | | | | | | | | | | | | | | | | commit 3aff47c062b944a5e1f9af56a37a23f5295628fc upstream. When EVA is enabled, flush the Return Prediction Stack (RPS) present on some MIPS cores on entry to the kernel from user mode. This is important specifically for interAptiv with EVA enabled, otherwise kernel mode RPS mispredicts may trigger speculative fetches of user return addresses, which may be sensitive in the kernel address space due to EVA's overlapping user/kernel address spaces. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10812/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
* MIPS: show_stack: Fix stack trace with EVAJames Hogan2015-08-271-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 1e77863a51698c4319587df34171bd823691a66a upstream. The show_stack() function deals exclusively with kernel contexts, but if it gets called in user context with EVA enabled, show_stacktrace() will attempt to access the stack using EVA accesses, which will either read other user mapped data, or more likely cause an exception which will be handled by __get_user(). This is easily reproduced using SysRq t to show all task states, which results in the following stack dump output: Stack : (Bad stack address) Fix by setting the current user access mode to kernel around the call to show_stacktrace(). This causes __get_user() to use normal loads to read the kernel stack. Now we get the correct output, like this: Stack : 00000000 80168960 00000000 004a0000 00000000 00000000 8060016c 1f3abd0c 1f172cd8 8056f09c 7ff1e450 8014fc3c 00000001 806dd0b0 0000001d 00000002 1f17c6a0 1f17c804 1f17c6a0 8066f6e0 00000000 0000000a 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 0110e800 1f3abd6c 1f17c6a0 ... Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10778/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
* MIPS: do_mcheck: Fix kernel code dump with EVAJames Hogan2015-08-271-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | commit 55c723e181ccec30fb5c672397fe69ec35967d97 upstream. If a machine check exception is raised in kernel mode, user context, with EVA enabled, then the do_mcheck handler will attempt to read the code around the EPC using EVA load instructions, i.e. as if the reads were from user mode. This will either read random user data if the process has anything mapped at the same address, or it will cause an exception which is handled by __get_user, resulting in this output: Code: (Bad address in epc) Fix by setting the current user access mode to kernel if the saved register context indicates the exception was taken in kernel mode. This causes __get_user to use normal loads to read the kernel code. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10777/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
* MIPS: Malta: Don't reinitialise RTCJames Hogan2015-08-271-6/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 106eccb4d20f35ebc58ff2286c170d9e79c5ff68 upstream. On Malta, since commit a87ea88d8f6c ("MIPS: Malta: initialise the RTC at boot"), the RTC is reinitialised and forced into binary coded decimal (BCD) mode during init, even if the bootloader has already initialised it, and may even have already put it into binary mode (as YAMON does). This corrupts the current time, can result in the RTC seconds being an invalid BCD (e.g. 0x1a..0x1f) for up to 6 seconds, as well as confusing YAMON for a while after reset, enough for it to report timeouts when attempting to load from TFTP (it actually uses the RTC in that code). Therefore only initialise the RTC to the extent that is necessary so that Linux avoids interfering with the bootloader setup, while also allowing it to estimate the CPU frequency without hanging, without a bootloader necessarily having done anything with the RTC (for example when the kernel is loaded via EJTAG). The divider control is configured for a 32KHZ reference clock if necessary, and the SET bit of the RTC_CONTROL register is cleared if necessary without changing any other bits (this bit will be set when coming out of reset if the battery has been disconnected). Fixes: a87ea88d8f6c ("MIPS: Malta: initialise the RTC at boot") Signed-off-by: James Hogan <james.hogan@imgtec.com> Reviewed-by: Paul Burton <paul.burton@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Maciej W. Rozycki <macro@linux-mips.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10739/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
* MIPS: Fix sched_getaffinity with MT FPAFF enabledFelix Fietkau2015-08-271-2/+3
| | | | | | | | | | | | | | | | commit 1d62d737555e1378eb62a8bba26644f7d97139d2 upstream. p->thread.user_cpus_allowed is zero-initialized and is only filled on the first sched_setaffinity call. To avoid adding overhead in the task initialization codepath, simply OR the returned mask in sched_getaffinity with p->cpus_allowed. Signed-off-by: Felix Fietkau <nbd@openwrt.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10740/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
* MIPS: kernel: traps: Fix broken indentationMarkos Chandras2015-08-101-4/+4
| | | | | | | | | | | | | | | commit 761b4493bbb7b614387794f39e3969716e9e0215 upstream. Fix broken indentation caused by the SMTC removal commit b633648c5ad3cfbda0b3daea50d2135d44899259 ("MIPS: MT: Remove SMTC support") Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Fixes: b633648c5ad3c ("MIPS: MT: Remove SMTC support") Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10581/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com>