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2017-06-24MIPS: Fix bnezc/jialc return address calculationPaul Burton
commit 1a73d9310e093fc3adffba4d0a67b9fab2ee3f63 upstream. The code handling the pop76 opcode (ie. bnezc & jialc instructions) in __compute_return_epc_for_insn() needs to set the value of $31 in the jialc case, which is encoded with rs = 0. However its check to differentiate bnezc (rs != 0) from jialc (rs = 0) was unfortunately backwards, meaning that if we emulate a bnezc instruction we clobber $31 & if we emulate a jialc instruction it actually behaves like a jic instruction. Fix this by inverting the check of rs to match the way the instructions are actually encoded. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Fixes: 28d6f93d201d ("MIPS: Emulate the new MIPS R6 BNEZC and JIALC instructions") Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16178/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-14MIPS: R2-on-R6 MULTU/MADDU/MSUBU emulation bugfixLeonid Yegoshin
commit d65e5677ad5b3a49c43f60ec07644dc1f87bbd2e upstream. MIPS instructions MULTU, MADDU and MSUBU emulation requires registers HI/LO to be converted to signed 32bits before 64bit sign extension on MIPS64. Bug was found on running MIPS32 R2 test application on MIPS64 R6 kernel. Fixes: b0a668fb2038 ("MIPS: kernel: mips-r2-to-r6-emul: Add R2 emulator for MIPS R6") Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Reported-by: Nikola.Veljkovic@imgtec.com Cc: paul.burton@imgtec.com Cc: yamada.masahiro@socionext.com Cc: akpm@linux-foundation.org Cc: andrea.gelmini@gelma.net Cc: macro@imgtec.com Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14043/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-03MIPS: Avoid BUG warning in arch_check_elfJames Cowgill
commit c46f59e90226fa5bfcc83650edebe84ae47d454b upstream. arch_check_elf contains a usage of current_cpu_data that will call smp_processor_id() with preemption enabled and therefore triggers a "BUG: using smp_processor_id() in preemptible" warning when an fpxx executable is loaded. As a follow-up to commit b244614a60ab ("MIPS: Avoid a BUG warning during prctl(PR_SET_FP_MODE, ...)"), apply the same fix to arch_check_elf by using raw_current_cpu_data instead. The rationale quoted from the previous commit: "It is assumed throughout the kernel that if any CPU has an FPU, then all CPUs would have an FPU as well, so it is safe to perform the check with preemption enabled - change the code to use raw_ variant of the check to avoid the warning." Fixes: 46490b572544 ("MIPS: kernel: elf: Improve the overall ABI and FPU mode checks") Signed-off-by: James Cowgill <James.Cowgill@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/15951/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-03MIPS: cevt-r4k: Fix out-of-bounds array accessJames Hogan
commit 9d7f29cdb4ca53506115cf1d7a02ce6013894df0 upstream. calculate_min_delta() may incorrectly access a 4th element of buf2[] which only has 3 elements. This may trigger undefined behaviour and has been reported to cause strange crashes in start_kernel() sometime after timer initialization when built with GCC 5.3, possibly due to register/stack corruption: sched_clock: 32 bits at 200MHz, resolution 5ns, wraps every 10737418237ns CPU 0 Unable to handle kernel paging request at virtual address ffffb0aa, epc == 8067daa8, ra == 8067da84 Oops[#1]: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.9.18 #51 task: 8065e3e0 task.stack: 80644000 $ 0 : 00000000 00000001 00000000 00000000 $ 4 : 8065b4d0 00000000 805d0000 00000010 $ 8 : 00000010 80321400 fffff000 812de408 $12 : 00000000 00000000 00000000 ffffffff $16 : 00000002 ffffffff 80660000 806a666c $20 : 806c0000 00000000 00000000 00000000 $24 : 00000000 00000010 $28 : 80644000 80645ed0 00000000 8067da84 Hi : 00000000 Lo : 00000000 epc : 8067daa8 start_kernel+0x33c/0x500 ra : 8067da84 start_kernel+0x318/0x500 Status: 11000402 KERNEL EXL Cause : 4080040c (ExcCode 03) BadVA : ffffb0aa PrId : 0501992c (MIPS 1004Kc) Modules linked in: Process swapper/0 (pid: 0, threadinfo=80644000, task=8065e3e0, tls=00000000) Call Trace: [<8067daa8>] start_kernel+0x33c/0x500 Code: 24050240 0c0131f9 24849c64 <a200b0a8> 41606020 000000c0 0c1a45e6 00000000 0c1a5f44 UBSAN also detects the same issue: ================================================================ UBSAN: Undefined behaviour in arch/mips/kernel/cevt-r4k.c:85:41 load of address 80647e4c with insufficient space for an object of type 'unsigned int' CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.9.18 #47 Call Trace: [<80028f70>] show_stack+0x88/0xa4 [<80312654>] dump_stack+0x84/0xc0 [<8034163c>] ubsan_epilogue+0x14/0x50 [<803417d8>] __ubsan_handle_type_mismatch+0x160/0x168 [<8002dab0>] r4k_clockevent_init+0x544/0x764 [<80684d34>] time_init+0x18/0x90 [<8067fa5c>] start_kernel+0x2f0/0x500 ================================================================= buf2[] is intentionally only 3 elements so that the last element is the median once 5 samples have been inserted, so explicitly prevent the possibility of comparing against the 4th element rather than extending the array. Fixes: 1fa405552e33f2 ("MIPS: cevt-r4k: Dynamically calculate min_delta_ns") Reported-by: Rabin Vincent <rabinv@axis.com> Signed-off-by: James Hogan <james.hogan@imgtec.com> Tested-by: Rabin Vincent <rabinv@axis.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/15892/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-03MIPS: KGDB: Use kernel context for sleeping threadsJames Hogan
commit 162b270c664dca2e0944308e92f9fcc887151a72 upstream. KGDB is a kernel debug stub and it can't be used to debug userland as it can only safely access kernel memory. On MIPS however KGDB has always got the register state of sleeping processes from the userland register context at the beginning of the kernel stack. This is meaningless for kernel threads (which never enter userland), and for user threads it prevents the user seeing what it is doing while in the kernel: (gdb) info threads Id Target Id Frame ... 3 Thread 2 (kthreadd) 0x0000000000000000 in ?? () 2 Thread 1 (init) 0x000000007705c4b4 in ?? () 1 Thread -2 (shadowCPU0) 0xffffffff8012524c in arch_kgdb_breakpoint () at arch/mips/kernel/kgdb.c:201 Get the register state instead from the (partial) kernel register context stored in the task's thread_struct for resume() to restore. All threads now correctly appear to be in context_switch(): (gdb) info threads Id Target Id Frame ... 3 Thread 2 (kthreadd) context_switch (rq=<optimized out>, cookie=..., next=<optimized out>, prev=0x0) at kernel/sched/core.c:2903 2 Thread 1 (init) context_switch (rq=<optimized out>, cookie=..., next=<optimized out>, prev=0x0) at kernel/sched/core.c:2903 1 Thread -2 (shadowCPU0) 0xffffffff8012524c in arch_kgdb_breakpoint () at arch/mips/kernel/kgdb.c:201 Call clobbered registers which aren't saved and exception registers (BadVAddr & Cause) which can't be easily determined without stack unwinding are reported as 0. The PC is taken from the return address, such that the state presented matches that found immediately after returning from resume(). Fixes: 8854700115ec ("[MIPS] kgdb: add arch support for the kernel's kgdb core") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/15829/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-18MIPS: IRQ Stack: Fix erroneous jal to plat_irq_dispatchMatt Redfearn
commit c25f8064c1d5731a2ce5664def890140dcdd3e5c upstream. Commit dda45f701c9d ("MIPS: Switch to the irq_stack in interrupts") changed both the normal and vectored interrupt handlers. Unfortunately the vectored version, "except_vec_vi_handler", was incorrectly modified to unconditionally jal to plat_irq_dispatch, rather than doing a jalr to the vectored handler that has been set up. This is ok for many platforms which set the vectored handler to plat_irq_dispatch anyway, but will cause problems with platforms that use other handlers. Fixes: dda45f701c9d ("MIPS: Switch to the irq_stack in interrupts") Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/15110/ Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Amit Pundir <amit.pundir@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-18MIPS: Switch to the irq_stack in interruptsMatt Redfearn
commit dda45f701c9d7ad4ac0bb446e3a96f6df9a468d9 upstream. When enterring interrupt context via handle_int or except_vec_vi, switch to the irq_stack of the current CPU if it is not already in use. The current stack pointer is masked with the thread size and compared to the base or the irq stack. If it does not match then the stack pointer is set to the top of that stack, otherwise this is a nested irq being handled on the irq stack so the stack pointer should be left as it was. The in-use stack pointer is placed in the callee saved register s1. It will be saved to the stack when plat_irq_dispatch is invoked and can be restored once control returns here. Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Acked-by: Jason A. Donenfeld <jason@zx2c4.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/14743/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Amit Pundir <amit.pundir@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-18MIPS: Stack unwinding while on IRQ stackMatt Redfearn
commit d42d8d106b0275b027c1e8992c42aecf933436ea upstream. Within unwind stack, check if the stack pointer being unwound is within the CPU's irq_stack and if so use that page rather than the task's stack page. Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Acked-by: Jason A. Donenfeld <jason@zx2c4.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Adam Buchbinder <adam.buchbinder@gmail.com> Cc: Maciej W. Rozycki <macro@imgtec.com> Cc: Marcin Nowakowski <marcin.nowakowski@imgtec.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/14741/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Amit Pundir <amit.pundir@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-18MIPS: Introduce irq_stackMatt Redfearn
commit fe8bd18ffea5327344d4ec2bf11f47951212abd0 upstream. Allocate a per-cpu irq stack for use within interrupt handlers. Also add a utility function on_irq_stack to determine if a given stack pointer is within the irq stack for that cpu. Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Acked-by: Jason A. Donenfeld <jason@zx2c4.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Petr Mladek <pmladek@suse.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14740/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Amit Pundir <amit.pundir@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-12MIPS: Add MIPS_CPU_FTLB for Loongson-3A R2Huacai Chen
commit 033cffeedbd11c140952b98e8639bf652091a17d upstream. Loongson-3A R2 and newer CPU have FTLB, but Config0.MT is 1, so add MIPS_CPU_FTLB to the CPU options. Signed-off-by: Huacai Chen <chenhc@lemote.com> Cc: John Crispin <john@phrozen.org> Cc: Steven J . Hill <Steven.Hill@caviumnetworks.com> Cc: Fuxin Zhang <zhangfx@lemote.com> Cc: Zhangjin Wu <wuzhangjin@gmail.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/15752/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-12MIPS: Check TLB before handle_ri_rdhwr() for Loongson-3Huacai Chen
commit 5a34133167dce36666ea054e30a561b7f4413b7f upstream. Loongson-3's micro TLB (ITLB) is not strictly a subset of JTLB. That means: when a JTLB entry is replaced by hardware, there may be an old valid entry exists in ITLB. So, a TLB miss exception may occur while handle_ri_rdhwr() is running because it try to access EPC's content. However, handle_ri_rdhwr() doesn't clear EXL, which makes a TLB Refill exception be treated as a TLB Invalid exception and tlbp may fail. In this case, if FTLB (which is usually set-associative instead of set- associative) is enabled, a tlbp failure will cause an invalid tlbwi, which will hang the whole system. This patch rename handle_ri_rdhwr_vivt to handle_ri_rdhwr_tlbp and use it for Loongson-3. It try to solve the same problem described as below, but more straightforwards. https://patchwork.linux-mips.org/patch/12591/ I think Loongson-2 has the same problem, but it has no FTLB, so we just keep it as is. Signed-off-by: Huacai Chen <chenhc@lemote.com> Cc: Rui Wang <wangr@lemote.com> Cc: John Crispin <john@phrozen.org> Cc: Steven J . Hill <Steven.Hill@caviumnetworks.com> Cc: Fuxin Zhang <zhangfx@lemote.com> Cc: Zhangjin Wu <wuzhangjin@gmail.com> Cc: Huacai Chen <chenhc@lemote.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/15753/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31mips/ptrace: Preserve previous registers for short regset writeDave Martin
commit d614fd58a2834cfe4efa472c33c8f3ce2338b09b upstream. Ensure that if userspace supplies insufficient data to PTRACE_SETREGSET to fill all the registers, the thread's old registers are preserved. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-12MIPS: Handle microMIPS jumps in the same way as MIPS32/MIPS64 jumpsPaul Burton
commit 096a0de427ea333f56f0ee00328cff2a2731bcf1 upstream. is_jump_ins() checks for plain jump ("j") instructions since commit e7438c4b893e ("MIPS: Fix sibling call handling in get_frame_info") but that commit didn't make the same change to the microMIPS code, leaving it inconsistent with the MIPS32/MIPS64 code. Handle the microMIPS encoding of the jump instruction too such that it behaves consistently. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Fixes: e7438c4b893e ("MIPS: Fix sibling call handling in get_frame_info") Cc: Tony Wu <tung7970@gmail.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14533/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-12MIPS: Calculate microMIPS ra properly when unwinding the stackPaul Burton
commit bb9bc4689b9c635714fbcd5d335bad9934a7ebfc upstream. get_frame_info() calculates the offset of the return address within a stack frame simply by dividing a the bottom 16 bits of the instruction, treated as a signed integer, by the size of a long. Whilst this works for MIPS32 & MIPS64 ISAs where the sw or sd instructions are used, it's incorrect for microMIPS where encodings differ. The result is that we typically completely fail to unwind the stack on microMIPS. Fix this by adjusting is_ra_save_ins() to calculate the return address offset, and take into account the various different encodings there in the same place as we consider whether an instruction is storing the ra/$31 register. With this we are now able to unwind the stack for kernels targetting the microMIPS ISA, for example we can produce: Call Trace: [<80109e1f>] show_stack+0x63/0x7c [<8011ea17>] __warn+0x9b/0xac [<8011ea45>] warn_slowpath_fmt+0x1d/0x20 [<8013fe53>] register_console+0x43/0x314 [<8067c58d>] of_setup_earlycon+0x1dd/0x1ec [<8067f63f>] early_init_dt_scan_chosen_stdout+0xe7/0xf8 [<8066c115>] do_early_param+0x75/0xac [<801302f9>] parse_args+0x1dd/0x308 [<8066c459>] parse_early_options+0x25/0x28 [<8066c48b>] parse_early_param+0x2f/0x38 [<8066e8cf>] setup_arch+0x113/0x488 [<8066c4f3>] start_kernel+0x57/0x328 ---[ end trace 0000000000000000 ]--- Whereas previously we only produced: Call Trace: [<80109e1f>] show_stack+0x63/0x7c ---[ end trace 0000000000000000 ]--- Signed-off-by: Paul Burton <paul.burton@imgtec.com> Fixes: 34c2f668d0f6 ("MIPS: microMIPS: Add unaligned access support.") Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14532/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-12MIPS: Fix is_jump_ins() handling of 16b microMIPS instructionsPaul Burton
commit 67c75057709a6d85c681c78b9b2f9b71191f01a2 upstream. is_jump_ins() checks 16b instruction fields without verifying that the instruction is indeed 16b, as is done by is_ra_save_ins() & is_sp_move_ins(). Add the appropriate check. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Fixes: 34c2f668d0f6 ("MIPS: microMIPS: Add unaligned access support.") Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14531/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-12MIPS: Fix get_frame_info() handling of microMIPS function sizePaul Burton
commit b6c7a324df37bf05ef7a2c1580683cf10d082d97 upstream. get_frame_info() is meant to iterate over up to the first 128 instructions within a function, but for microMIPS kernels it will not reach that many instructions unless the function is 512 bytes long since we calculate the maximum number of instructions to check by dividing the function length by the 4 byte size of a union mips_instruction. In microMIPS kernels this won't do since instructions are variable length. Fix this by instead checking whether the pointer to the current instruction has reached the end of the function, and use max_insns as a simple constant to check the number of iterations against. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Fixes: 34c2f668d0f6 ("MIPS: microMIPS: Add unaligned access support.") Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14530/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-12MIPS: Prevent unaligned accesses during stack unwindingPaul Burton
commit a3552dace7d1d0cabf573e88fc3025cb90c4a601 upstream. During stack unwinding we call a number of functions to determine what type of instruction we're looking at. The union mips_instruction pointer provided to them may be pointing at a 2 byte, but not 4 byte, aligned address & we thus cannot directly access the 4 byte wide members of the union mips_instruction. To avoid this is_ra_save_ins() copies the required half-words of the microMIPS instruction to a correctly aligned union mips_instruction on the stack, which it can then access safely. The is_jump_ins() & is_sp_move_ins() functions do not correctly perform this temporary copy, and instead attempt to directly dereference 4 byte fields which may be misaligned and lead to an address exception. Fix this by copying the instruction halfwords to a temporary union mips_instruction in get_frame_info() such that we can provide a 4 byte aligned union mips_instruction to the is_*_ins() functions and they do not need to deal with misalignment themselves. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Fixes: 34c2f668d0f6 ("MIPS: microMIPS: Add unaligned access support.") Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14529/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-12MIPS: Clear ISA bit correctly in get_frame_info()Paul Burton
commit ccaf7caf2c73c6db920772bf08bf1d47b2170634 upstream. get_frame_info() can be called in microMIPS kernels with the ISA bit already clear. For example this happens when unwind_stack_by_address() is called because we begin with a PC that has the ISA bit set & subtract the (odd) offset from the preceding symbol (which does not have the ISA bit set). Since get_frame_info() unconditionally subtracts 1 from the PC in microMIPS kernels it incorrectly misaligns the address it then attempts to access code at, leading to an address error exception. Fix this by using msk_isa16_mode() to clear the ISA bit, which allows get_frame_info() to function regardless of whether it is provided with a PC that has the ISA bit set or not. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Fixes: 34c2f668d0f6 ("MIPS: microMIPS: Add unaligned access support.") Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14528/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-06ptrace: Don't allow accessing an undumpable mmEric W. Biederman
commit 84d77d3f06e7e8dea057d10e8ec77ad71f721be3 upstream. It is the reasonable expectation that if an executable file is not readable there will be no way for a user without special privileges to read the file. This is enforced in ptrace_attach but if ptrace is already attached before exec there is no enforcement for read-only executables. As the only way to read such an mm is through access_process_vm spin a variant called ptrace_access_vm that will fail if the target process is not being ptraced by the current process, or the current process did not have sufficient privileges when ptracing began to read the target processes mm. In the ptrace implementations replace access_process_vm by ptrace_access_vm. There remain several ptrace sites that still use access_process_vm as they are reading the target executables instructions (for kernel consumption) or register stacks. As such it does not appear necessary to add a permission check to those calls. This bug has always existed in Linux. Fixes: v1.0 Reported-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-12-11MIPS: Return -ENODEV from weak implementation of rtc_mips_set_timeLuuk Paulussen
The sync_cmos_clock function in kernel/time/ntp.c first tries to update the internal clock of the cpu by calling the "update_persistent_clock64" architecture specific function. If this returns -ENODEV, it then tries to update an external RTC using "rtc_set_ntp_time". On the mips architecture, the weak implementation of the underlying function would return 0 if it wasn't overridden. This meant that the sync_cmos_clock function would never try to update an external RTC (if both CONFIG_GENERIC_CMOS_UPDATE and CONFIG_RTC_SYSTOHC are configured) Returning -ENODEV instead, means that an external RTC will be tried. Signed-off-by: Luuk Paulussen <luuk.paulussen@alliedtelesis.co.nz> Reviewed-by: Richard Laing <richard.laing@alliedtelesis.co.nz> Reviewed-by: Scott Parlane <scott.parlane@alliedtelesis.co.nz> Reviewed-by: Chris Packham <chris.packham@alliedtelesis.co.nz> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14649/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-11-04MIPS: Fix max_low_pfn with disabled highmemJames Hogan
When low memory doesn't reach HIGHMEM_START (e.g. up to 256MB at PA=0 is common) and highmem is present above HIGHMEM_START (e.g. on Malta the RAM overlayed by the IO region is aliased at PA=0x90000000), max_low_pfn will be initially calculated very large and then clipped down to HIGHMEM_START. This causes crashes when reading /sys/kernel/mm/page_idle/bitmap (i.e. CONFIG_IDLE_PAGE_TRACKING=y) when highmem is disabled. pfn_valid() will compare against max_mapnr which is derived from max_low_pfn when there is no highend_pfn set up, and will return true for PFNs right up to HIGHMEM_START, even though they are beyond the end of low memory and no page structs will actually exist for these PFNs. This is fixed by skipping high memory regions when initially calculating max_low_pfn if highmem is disabled, so it doesn't get clipped too high. We also clip regions which overlap the highmem boundary when highmem is disabled, so that max_pfn doesn't extend into highmem either. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14490/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-11-04MIPS: Correct MIPS I FP sigcontext layoutMaciej W. Rozycki
Complement commit 80cbfad79096 ("MIPS: Correct MIPS I FP context layout") and correct the way Floating Point General registers are stored in a signal context with MIPS I hardware. Use the S.D and L.D assembly macros to have pairs of SWC1 instructions and pairs of LWC1 instructions produced, respectively, in an arrangement which makes the memory representation of floating-point data passed compatible with that used by hardware SDC1 and LDC1 instructions, where available, regardless of the hardware endianness used. This matches the layout used by r4k_fpu.S, ensuring run-time compatibility for MIPS I software across all o32 hardware platforms. Define an EX2 macro to handle exceptions from both hardware instructions implicitly produced from S.D and L.D assembly macros. Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/14477/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-11-04MIPS: Fix ISA I/II FP signal context offsetsMaciej W. Rozycki
Fix a regression introduced with commit 2db9ca0a3551 ("MIPS: Use struct mips_abi offsets to save FP context") for MIPS I/I FP signal contexts, by converting save/restore code to the updated internal API. Start FGR offsets from 0 rather than SC_FPREGS from $a0 and use $a1 rather than the offset of SC_FPC_CSR from $a0 for the Floating Point Control/Status Register (FCSR). Document the new internal API and adjust assembly code formatting for consistency. Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/14476/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-11-04MIPS: Remove FIR from ISA I FP signal contextMaciej W. Rozycki
Complement commit e50c0a8fa60d ("Support the MIPS32 / MIPS64 DSP ASE.") and remove the Floating Point Implementation Register (FIR) from the FP register set recorded in a signal context with MIPS I processors too, in line with the change applied to r4k_fpu.S. The `sc_fpc_eir' slot is unused according to our current ABI and the FIR register is read-only and always directly accessible from user software. [ralf@linux-mips.org: This is also required because the next commit depends on it.] Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/14475/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-11-04MIPS: Fix ISA I FP sigcontext access violation handlingMaciej W. Rozycki
Complement commit 0ae8dceaebe3 ("Merge with 2.3.10.") and use the local `fault' handler to recover from FP sigcontext access violation faults, like corresponding code does in r4k_fpu.S. The `bad_stack' handler is in syscall.c and is not suitable here as we want to propagate the error condition up through the caller rather than killing the thread outright. Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/14474/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-11-04MIPS: Fix FCSR Cause bit handling for correct SIGFPE issueMaciej W. Rozycki
Sanitize FCSR Cause bit handling, following a trail of past attempts: * commit 4249548454f7 ("MIPS: ptrace: Fix FP context restoration FCSR regression"), * commit 443c44032a54 ("MIPS: Always clear FCSR cause bits after emulation"), * commit 64bedffe4968 ("MIPS: Clear [MSA]FPE CSR.Cause after notify_die()"), * commit b1442d39fac2 ("MIPS: Prevent user from setting FCSR cause bits"), * commit b54d2901517d ("Properly handle branch delay slots in connection with signals."). Specifically do not mask these bits out in ptrace(2) processing and send a SIGFPE signal instead whenever a matching pair of an FCSR Cause and Enable bit is seen as execution of an affected context is about to resume. Only then clear Cause bits, and even then do not clear any bits that are set but masked with the respective Enable bits. Adjust Cause bit clearing throughout code likewise, except within the FPU emulator proper where they are set according to IEEE 754 exceptions raised as the operation emulated executed. Do so so that any IEEE 754 exceptions subject to their default handling are recorded like with operations executed by FPU hardware. Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Cc: Paul Burton <paul.burton@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/14460/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-11-04MIPS: ptrace: Also initialize the FP context on individual FCSR writesMaciej W. Rozycki
Complement commit ac9ad83bc318 ("MIPS: prevent FP context set via ptrace being discarded") and also initialize the FP context whenever FCSR alone is written with a PTRACE_POKEUSR request addressing FPC_CSR, rather than along with the full FPU register set in the case of the PTRACE_SETFPREGS request. Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Cc: Paul Burton <paul.burton@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/14459/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-11-04MIPS: Fix __show_regs() outputPaul Burton
Since commit 4bcc595ccd80 ("printk: reinstate KERN_CONT for printing continuation lines") the output from __show_regs() on MIPS has been pretty unreadable due to the lack of KERN_CONT markers. Use pr_cont to provide the appropriate markers & restore the expected register output. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Signed-off-by: Matt Redfearn <matt.redfearn@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/14432/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-11-04MIPS: traps: Fix output of show_codeMatt Redfearn
Since commit 4bcc595ccd80 ("printk: reinstate KERN_CONT for printing continuation lines") the output from show_code on MIPS has been pretty unreadable due to the lack of KERN_CONT markers. Use pr_cont to provide the appropriate markers & restore the expected output. Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Maciej W. Rozycki <macro@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/14431/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-11-03MIPS: traps: Fix output of show_stacktraceMatt Redfearn
Since commit 4bcc595ccd80 ("printk: reinstate KERN_CONT for printing continuation lines") the output from show_stacktrace on MIPS has been pretty unreadable due to the lack of KERN_CONT markers. Use pr_cont to provide the appropriate markers & restore the expected output. Also start a new line with printk such that the presence of timing information does not interfere with output. Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Maciej W. Rozycki <macro@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/14430/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-11-03MIPS: traps: Fix output of show_backtraceMatt Redfearn
Since commit 4bcc595ccd80 ("printk: reinstate KERN_CONT for printing continuation lines") the output from show_backtrace on MIPS has been pretty unreadable due to the lack of KERN_CONT markers. Use pr_cont to provide the appropriate markers & restore the expected output. Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Maciej W. Rozycki <macro@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/14429/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-11-03MIPS: KASLR: Fix handling of NULL FDTMatt Redfearn
If platform code returns a NULL pointer to the FDT, initial_boot_params will not get set to a valid pointer and attempting to find the /chosen node in it will cause a NULL pointer dereference and the kernel to crash immediately on startup - with no output to the console. Fix this by checking that initial_boot_params is valid before using it. Fixes: 405bc8fd12f5 ("MIPS: Kernel: Implement KASLR using CONFIG_RELOCATABLE") Cc: stable@vger.kernel.org # 4.7+ 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/14414/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-11-03MIPS: CPC: Provide default mips_cpc_default_phys_base to ignore CPCPaul Burton
Provide a default implementation of mips_cpc_default_phys_base() which simply returns 0, and adjust mips_cpc_phys_base() to allow for mips_cpc_default_phys_base() returning 0. This allows kernels which include CPC support to be built without platform code & simply ignore the CPC if it wasn't already enabled by the bootloader. This fixes link failures such as the following from generic defconfigs: arch/mips/built-in.o: In function `mips_cpc_phys_base': arch/mips/kernel/mips-cpc.c:47: undefined reference to `mips_cpc_default_phys_base' [ralf@linux-mips.org: changed prototype for coding style compliance.] Signed-off-by: Paul Burton <paul.burton@imgtec.com> Reported-by: kbuild test robot <fengguang.wu@intel.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14401/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-10-19Merge branch 'gup_flag-cleanups'Linus Torvalds
Merge the gup_flags cleanups from Lorenzo Stoakes: "This patch series adjusts functions in the get_user_pages* family such that desired FOLL_* flags are passed as an argument rather than implied by flags. The purpose of this change is to make the use of FOLL_FORCE explicit so it is easier to grep for and clearer to callers that this flag is being used. The use of FOLL_FORCE is an issue as it overrides missing VM_READ/VM_WRITE flags for the VMA whose pages we are reading from/writing to, which can result in surprising behaviour. The patch series came out of the discussion around commit 38e088546522 ("mm: check VMA flags to avoid invalid PROT_NONE NUMA balancing"), which addressed a BUG_ON() being triggered when a page was faulted in with PROT_NONE set but having been overridden by FOLL_FORCE. do_numa_page() was run on the assumption the page _must_ be one marked for NUMA node migration as an actual PROT_NONE page would have been dealt with prior to this code path, however FOLL_FORCE introduced a situation where this assumption did not hold. See https://marc.info/?l=linux-mm&m=147585445805166 for the patch proposal" Additionally, there's a fix for an ancient bug related to FOLL_FORCE and FOLL_WRITE by me. [ This branch was rebased recently to add a few more acked-by's and reviewed-by's ] * gup_flag-cleanups: mm: replace access_process_vm() write parameter with gup_flags mm: replace access_remote_vm() write parameter with gup_flags mm: replace __access_remote_vm() write parameter with gup_flags mm: replace get_user_pages_remote() write/force parameters with gup_flags mm: replace get_user_pages() write/force parameters with gup_flags mm: replace get_vaddr_frames() write/force parameters with gup_flags mm: replace get_user_pages_locked() write/force parameters with gup_flags mm: replace get_user_pages_unlocked() write/force parameters with gup_flags mm: remove write/force parameters from __get_user_pages_unlocked() mm: remove write/force parameters from __get_user_pages_locked() mm: remove gup_flags FOLL_WRITE games from __get_user_pages()
2016-10-19mm: replace access_process_vm() write parameter with gup_flagsLorenzo Stoakes
This removes the 'write' argument from access_process_vm() and replaces it with 'gup_flags' as use of this function previously silently implied FOLL_FORCE, whereas after this patch callers explicitly pass this flag. We make this explicit as use of FOLL_FORCE can result in surprising behaviour (and hence bugs) within the mm subsystem. Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-15Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds
Pull MIPS updates from Ralf Baechle: "This is the main MIPS pull request for 4.9: MIPS core arch code: - traps: 64bit kernels should read CP0_EBase 64bit - traps: Convert ebase to KSEG0 - c-r4k: Drop bc_wback_inv() from icache flush - c-r4k: Split user/kernel flush_icache_range() - cacheflush: Use __flush_icache_user_range() - uprobes: Flush icache via kernel address - KVM: Use __local_flush_icache_user_range() - c-r4k: Fix flush_icache_range() for EVA - Fix -mabi=64 build of vdso.lds - VDSO: Drop duplicated -I*/-E* aflags - tracing: move insn_has_delay_slot to a shared header - tracing: disable uprobe/kprobe on compact branch instructions - ptrace: Fix regs_return_value for kernel context - Squash lines for simple wrapper functions - Move identification of VP(E) into proc.c from smp-mt.c - Add definitions of SYNC barrierstype values - traps: Ensure full EBase is written - tlb-r4k: If there are wired entries, don't use TLBINVF - Sanitise coherentio semantics - dma-default: Don't check hw_coherentio if device is non-coherent - Support per-device DMA coherence - Adjust MIPS64 CAC_BASE to reflect Config.K0 - Support generating Flattened Image Trees (.itb) - generic: Introduce generic DT-based board support - generic: Convert SEAD-3 to a generic board - Enable hardened usercopy - Don't specify STACKPROTECTOR in defconfigs Octeon: - Delete dead code and files across the platform. - Change to use all memory into use by default. - Rename upper case variables in setup code to lowercase. - Delete legacy hack for broken bootloaders. - Leave maintaining the link state to the actual ethernet/PHY drivers. - Add DTS for D-Link DSR-500N. - Fix PCI interrupt routing on D-Link DSR-500N. Pistachio: - Remove ANDROID_TIMED_OUTPUT from defconfig TX39xx: - Move GPIO setup from .mem_setup() to .arch_init() - Convert to Common Clock Framework TX49xx: - Move GPIO setup from .mem_setup() to .arch_init() - Convert to Common Clock Framework txx9wdt: - Add missing clock (un)prepare calls for CCF BMIPS: - Add PW, GPIO SDHCI and NAND device node names - Support APPENDED_DTB - Add missing bcm97435svmb to DT_NONE - Rename bcm96358nb4ser to bcm6358-neufbox4-sercom - Add DT examples for BCM63268, BCM3368 and BCM6362 - Add support for BCM3368 and BCM6362 PCI - Reduce stack frame usage - Use struct list_head lists - Support for CONFIG_PCI_DOMAINS_GENERIC - Make pcibios_set_cache_line_size an initcall - Inline pcibios_assign_all_busses - Split pci.c into pci.c & pci-legacy.c - Introduce CONFIG_PCI_DRIVERS_LEGACY - Support generic drivers CPC - Convert bare 'unsigned' to 'unsigned int' - Avoid lock when MIPS CM >= 3 is present GIC: - Delete unused file smp-gic.c mt7620: - Delete unnecessary assignment for the field "owner" from PCI BCM63xx: - Let clk_disable() return immediately if clk is NULL pm-cps: - Change FSB workaround to CPU blacklist - Update comments on barrier instructions - Use MIPS standard lightweight ordering barrier - Use MIPS standard completion barrier - Remove selection of sync types - Add MIPSr6 CPU support - Support CM3 changes to Coherence Enable Register SMP: - Wrap call to mips_cpc_lock_other in mips_cm_lock_other - Introduce mechanism for freeing and allocating IPIs cpuidle: - cpuidle-cps: Enable use with MIPSr6 CPUs. SEAD3: - Rewrite to use DT and generic kernel feature. USB: - host: ehci-sead3: Remove SEAD-3 EHCI code FBDEV: - cobalt_lcdfb: Drop SEAD3 support dt-bindings: - Document a binding for simple ASCII LCDs auxdisplay: - img-ascii-lcd: driver for simple ASCII LCD displays irqchip i8259: - i8259: Add domain before mapping parent irq - i8259: Allow platforms to override poll function - i8259: Remove unused i8259A_irq_pending Malta: - Rewrite to use DT of/platform: - Probe "isa" busses by default CM: - Print CM error reports upon bus errors Module: - Migrate exception table users off module.h and onto extable.h - Make various drivers explicitly non-modular: - Audit and remove any unnecessary uses of module.h mailmap: - Canonicalize to Qais' current email address. Documentation: - MIPS supports HAVE_REGS_AND_STACK_ACCESS_API Loongson1C: - Add CPU support for Loongson1C - Add board support - Add defconfig - Add RTC support for Loongson1C board All this except one Documentation fix has sat in linux-next and has survived Imagination's automated build test system" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (127 commits) Documentation: MIPS supports HAVE_REGS_AND_STACK_ACCESS_API MIPS: ptrace: Fix regs_return_value for kernel context MIPS: VDSO: Drop duplicated -I*/-E* aflags MIPS: Fix -mabi=64 build of vdso.lds MIPS: Enable hardened usercopy MIPS: generic: Convert SEAD-3 to a generic board MIPS: generic: Introduce generic DT-based board support MIPS: Support generating Flattened Image Trees (.itb) MIPS: Adjust MIPS64 CAC_BASE to reflect Config.K0 MIPS: Print CM error reports upon bus errors MIPS: Support per-device DMA coherence MIPS: dma-default: Don't check hw_coherentio if device is non-coherent MIPS: Sanitise coherentio semantics MIPS: PCI: Support generic drivers MIPS: PCI: Introduce CONFIG_PCI_DRIVERS_LEGACY MIPS: PCI: Split pci.c into pci.c & pci-legacy.c MIPS: PCI: Inline pcibios_assign_all_busses MIPS: PCI: Make pcibios_set_cache_line_size an initcall MIPS: PCI: Support for CONFIG_PCI_DOMAINS_GENERIC MIPS: PCI: Use struct list_head lists ...
2016-10-14MIPS: Wire up new pkey_{mprotect,alloc,free} syscallsRalf Baechle
Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14380/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11mips/panic: replace smp_send_stop() with kdump friendly version in panic pathHidehiro Kawai
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>
2016-10-08nmi_backtrace: generate one-line reports for idle cpusChris Metcalf
When doing an nmi backtrace of many cores, most of which are idle, the output is a little overwhelming and very uninformative. Suppress messages for cpus that are idling when they are interrupted and just emit one line, "NMI backtrace for N skipped: idling at pc 0xNNN". We do this by grouping all the cpuidle code together into a new .cpuidle.text section, and then checking the address of the interrupted PC to see if it lies within that section. This commit suitably tags x86 and tile idle routines, and only adds in the minimal framework for other architectures. Link: http://lkml.kernel.org/r/1472487169-14923-5-git-send-email-cmetcalf@mellanox.com Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Daniel Thompson <daniel.thompson@linaro.org> [arm] Tested-by: Petr Mladek <pmladek@suse.com> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Russell King <linux@arm.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-08nmi_backtrace: add more trigger_*_cpu_backtrace() methodsChris Metcalf
Patch series "improvements to the nmi_backtrace code" v9. This patch series modifies the trigger_xxx_backtrace() NMI-based remote backtracing code to make it more flexible, and makes a few small improvements along the way. The motivation comes from the task isolation code, where there are scenarios where we want to be able to diagnose a case where some cpu is about to interrupt a task-isolated cpu. It can be helpful to see both where the interrupting cpu is, and also an approximation of where the cpu that is being interrupted is. The nmi_backtrace framework allows us to discover the stack of the interrupted cpu. I've tested that the change works as desired on tile, and build-tested x86, arm, mips, and sparc64. For x86 I confirmed that the generic cpuidle stuff as well as the architecture-specific routines are in the new cpuidle section. For arm, mips, and sparc I just build-tested it and made sure the generic cpuidle routines were in the new cpuidle section, but I didn't attempt to figure out which the platform-specific idle routines might be. That might be more usefully done by someone with platform experience in follow-up patches. This patch (of 4): Currently you can only request a backtrace of either all cpus, or all cpus but yourself. It can also be helpful to request a remote backtrace of a single cpu, and since we want that, the logical extension is to support a cpumask as the underlying primitive. This change modifies the existing lib/nmi_backtrace.c code to take a cpumask as its basic primitive, and modifies the linux/nmi.h code to use the new "cpumask" method instead. The existing clients of nmi_backtrace (arm and x86) are converted to using the new cpumask approach in this change. The other users of the backtracing API (sparc64 and mips) are converted to use the cpumask approach rather than the all/allbutself approach. The mips code ignored the "include_self" boolean but with this change it will now also dump a local backtrace if requested. Link: http://lkml.kernel.org/r/1472487169-14923-2-git-send-email-cmetcalf@mellanox.com Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com> Tested-by: Daniel Thompson <daniel.thompson@linaro.org> [arm] Reviewed-by: Aaron Tomlin <atomlin@redhat.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Russell King <linux@arm.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-06MIPS: Print CM error reports upon bus errorsPaul Burton
If a bus error occurs on a system with a MIPS Coherence Manager (CM) then the CM may hold useful diagnostic information. Printing this out has so far been left up to boards, with the requirement that they register a board_be_handler function & call mips_cm_error_decode() from there. In order to avoid boards other than Malta needing to duplicate this code, call mips_cm_error_decode() automatically if the board registers no board_be_handler, and remove the Malta implementation of that. This patch results in no functional change, but removes a further piece of platform-specific code. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14350/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-10-06MIPS: tracing: disable uprobe/kprobe on compact branch instructionsMarcin Nowakowski
Current instruction decoder for uprobe/kprobe handler only handles branches with delay slots. For compact branches the behaviour is rather unpredictable - and depending on the encoding of a compact branch instruction may result in one (or more) of: - executing an instruction that follows a branch which wasn't in a delay slot and shouldn't have been executed - incorrectly emulating a branch leading to a jump to a wrong location - unexpected branching out of the single-stepped code and never reaching the breakpoint that should terminate the probe handler Results of these actions are generally unpredictable, but can end up with a probed application or kernel crash, so disable placing probes on compact branches until they are handled properly. Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14336/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-10-06MIPS: tracing: move insn_has_delay_slot to a shared headerMarcin Nowakowski
Currently both kprobes and uprobes code have definitions of the insn_has_delay_slot method. Move it to a separate header as an inline method that each probe-specific method can later use. No functional change intended, although the methods slightly varied in the constraints they set for the methods - the uprobes one was chosen as it is slightly more specific when filtering opcode fields. Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14335/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-10-04MIPS: pm-cps: Generate idle state entry code when CPUs are onlinedPaul Burton
The MIPS Coherent Processing System (CPS) power management code has previously generated code used to enter low power idle states once during boot for all CPUs. This has the drawback that if a CPU is present in the system but not being used (for example due to the maxcpus kernel parameter) then we encounter problems due to not having probed that CPU for information about its type & properties. The result of this is that we generate entry code which is both unused, potentially entirely invalid & likely to be unsuitable for the CPU in question anyway. Avoid this by generating idle state entry code only when a CPU is brought online. This way we only ever generate code for CPUs that we know we've probed the properties of, and that will actually be used. [ralf@linux-mips.org: Resolve merge conflict.] Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Adam Buchbinder <adam.buchbinder@gmail.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/14259/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-10-04MIPS: kernel: Audit and remove any unnecessary uses of module.hPaul Gortmaker
Historically a lot of these existed because we did not have a distinction between what was modular code and what was providing support to modules via EXPORT_SYMBOL and friends. That changed when we forked out support for the latter into the export.h file. This means we should be able to reduce the usage of module.h in code that is obj-y Makefile or bool Kconfig. The advantage in doing so is that module.h itself sources about 15 other headers; adding significantly to what we feed cpp, and it can obscure what headers we are effectively using. Since module.h was the source for init.h (for __init) and for export.h (for EXPORT_SYMBOL) we consider each obj-y/bool instance for the presence of either and replace as needed. In the case of the n32/o32 files, we have to get rid of a couple no-op MODULE_ tags to facilitate the module.h removal. They piggy back off the fs/ elf binary support, which is also a bool Kconfig. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14032/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-10-04MIPS: smp.c: Introduce mechanism for freeing and allocating IPIsMatt Redfearn
For the MIPS remote processor implementation, we need additional IPIs to talk to the remote processor. Since MIPS GIC reserves exactly the right number of IPI IRQs required by Linux for the number of VPs in the system, this is not possible without releasing some recources. This commit introduces mips_smp_ipi_allocate() which allocates IPIs to a given cpumask. It is called as normal with the cpu_possible_mask at bootup to initialise IPIs to all CPUs. mips_smp_ipi_free() may then be used to free IPIs to a subset of those CPUs so that their hardware resources can be reused. Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Bjorn Andersson <bjorn.andersson@linaro.org> Cc: Ohad Ben-Cohen <ohad@wizery.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Lisa Parratt <Lisa.Parratt@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Qais Yousef <qsyousef@gmail.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-remoteproc@vger.kernel.org Cc: lisa.parratt@imgtec.com Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/14285/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-10-04MIPS: uprobes: Flush icache via kernel addressJames Hogan
Update arch_uprobe_copy_ixol() to use the kmap_atomic() based kernel address to flush the icache with flush_icache_range(), rather than the user mapping. We have the kernel mapping available anyway and this avoids having to switch to using the new __flush_icache_user_range() for the sake of Enhanced Virtual Addressing (EVA) where flush_icache_range() will become ineffective on user addresses. 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/14154/ Patchwork: https://patchwork.linux-mips.org/patch/14308/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-10-04MIPS: traps: Ensure full EBase is writtenMatt Redfearn
On CPUs which support the EBase WG (write gate) flag, the most significant bits of the exception base can be changed. Firmware running on a VP(E) using MIPS rproc may change EBase to point into the user segment where the firmware is located such that it can service interrupts. When control is transferred back to the kernel the EBase must be switched back into the kernel segment, such that the kernel's exception vectors are used. Similarly when vectored interrupts (vint) or vectored external interrupt controllers (veic) are enabled an exception vector is allocated from bootmem, and written to the EBase register. Due to the WG flag being clear, only bits 29:12 will be written. Asside from the rproc case above this is normally fine (as it will usually be a low allocation within the KSeg0 range, however when Enhanced Virtual Addressing (EVA) is enabled the allocation may be outside of the traditional KSeg0/KSeg1 address range, resulting in the wrong EBase being written. Correct both cases (configure_exception_vector() for the boot CPU, and per_cpu_trap_init() for secondary CPUs) to write EBase with the WG flag first if supported. On the Malta EVA configuration, KSeg0 is mapped to physical address 0, and memory is allocated from the KUSeg segment which is mapped to physical address 0x80000000, which physically aliases the RAM at 0. This only worked due to the exception base address aliasing the same underlying RAM that was written to & cache flushed, and due to flush_icache_range() going beyond the call of duty and flushing from the L2 cache too (due to the differing physical addresses). Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> 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/14150/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-10-04MIPS: traps: Convert ebase to KSEG0James Hogan
When allocating boot memory for the exception vector when vectored interrupts (vint) or vectored external interrupt controllers (veic) are enabled, try to ensure that the virtual address resides in KSeg0 (and WARN should that not be possible). This will be helpful on MIPS64 cores supporting the CP0_EBase Write Gate (WG) bit once we start using the WG bit to write the full ebase into CP0_EBase, as we ideally need to avoid hitting the architecturally poorly defined exception base for Cache Errors when CP0_EBase is in XKPhys. An exception is made for Enhanced Virtual Addressing (EVA) kernels which allow segments to be rearranged and to become uncached during cache error handling, making it valid for ebase to be elsewhere. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14149/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-10-04MIPS: traps: 64bit kernels should read CP0_EBase 64bitJames Hogan
When reading the CP0_EBase register containing the WG (write gate) bit, the ebase variable should be set to the full value of the register, i.e. on a 64-bit kernel the full 64-bit width of the register via read_cp0_ebase_64(), and on a 32-bit kernel the full 32-bit width including bits 31:30 which may be writeable. Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14148/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>