summaryrefslogtreecommitdiffstats
path: root/arch/mips
Commit message (Collapse)AuthorAgeFilesLines
* MIPS: KVM: Fix modular KVM under QEMUJames Hogan2017-10-124-1/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 797179bc4fe06c89e47a9f36f886f68640b423f8 upstream. Copy __kvm_mips_vcpu_run() into unmapped memory, so that we can never get a TLB refill exception in it when KVM is built as a module. This was observed to happen with the host MIPS kernel running under QEMU, due to a not entirely transparent optimisation in the QEMU TLB handling where TLB entries replaced with TLBWR are copied to a separate part of the TLB array. Code in those pages continue to be executable, but those mappings persist only until the next ASID switch, even if they are marked global. An ASID switch happens in __kvm_mips_vcpu_run() at exception level after switching to the guest exception base. Subsequent TLB mapped kernel instructions just prior to switching to the guest trigger a TLB refill exception, which enters the guest exception handlers without updating EPC. This appears as a guest triggered TLB refill on a host kernel mapped (host KSeg2) address, which is not handled correctly as user (guest) mode accesses to kernel (host) segments always generate address error exceptions. 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: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [james.hogan@imgtec.com: backported for stable 3.14] Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Fix 64k page support for 32 bit kernels.Ralf Baechle2017-10-121-1/+1
| | | | | | | | | | | | | commit d7de413475f443957a0c1d256e405d19b3a2cb22 upstream. TASK_SIZE was defined as 0x7fff8000UL which for 64k pages is not a multiple of the page size. Somewhere further down the math fails such that executing an ELF binary fails. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Tested-by: Joshua Henderson <joshua.henderson@microchip.com> Cc: James Hogan <james.hogan@imgtec.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Negate error syscall return in traceJames Hogan2017-10-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | | commit 4f32a39d49b25eaa66d2420f1f03d371ea4cd906 upstream. The sys_exit trace event takes a single return value for the system call, which MIPS passes the value of the $v0 (result) register, however MIPS returns positive error codes in $v0 with $a3 specifying that $v0 contains an error code. As a result erroring system calls are traced returning positive error numbers that can't always be distinguished from success. Use regs_return_value() to negate the error code if $a3 is set. Fixes: 1d7bf993e073 ("MIPS: ftrace: Add support for syscall tracepoints.") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16651/ Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Send SIGILL for BPOSGE32 in `__compute_return_epc_for_insn'Maciej W. Rozycki2017-10-121-3/+4
| | | | | | | | | | | | | | | | | | | | | | commit 7b82c1058ac1f8f8b9f2b8786b1f710a57a870a8 upstream. Fix commit e50c0a8fa60d ("Support the MIPS32 / MIPS64 DSP ASE.") and send SIGILL rather than SIGBUS whenever an unimplemented BPOSGE32 DSP ASE instruction has been encountered in `__compute_return_epc_for_insn' as our Reserved Instruction exception handler would in response to an attempt to actually execute the instruction. Sending SIGBUS only makes sense for the unaligned PC case, since moved to `__compute_return_epc'. Adjust function documentation accordingly, correct formatting and use `pr_info' rather than `printk' as the other exit path already does. Fixes: e50c0a8fa60d ("Support the MIPS32 / MIPS64 DSP ASE.") Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16396/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Fix unaligned PC interpretation in `compute_return_epc'Maciej W. Rozycki2017-10-121-4/+1
| | | | | | | | | | | | | | | | | | | | commit 11a3799dbeb620bf0400b1fda5cc2c6bea55f20a upstream. Fix a regression introduced with commit fb6883e5809c ("MIPS: microMIPS: Support handling of delay slots.") and defer to `__compute_return_epc' if the ISA bit is set in EPC with non-MIPS16, non-microMIPS hardware, which will then arrange for a SIGBUS due to an unaligned instruction reference. Returning EPC here is never correct as the API defines this function's result to be either a negative error code on failure or one of 0 and BRANCH_LIKELY_TAKEN on success. Fixes: fb6883e5809c ("MIPS: microMIPS: Support handling of delay slots.") Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16395/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Actually decode JALX in `__compute_return_epc_for_insn'Maciej W. Rozycki2017-10-121-0/+1
| | | | | | | | | | | | | | | | | commit a9db101b735a9d49295326ae41f610f6da62b08c upstream. Complement commit fb6883e5809c ("MIPS: microMIPS: Support handling of delay slots.") and actually decode the regular MIPS JALX major instruction opcode, the handling of which has been added with the said commit for EPC calculation in `__compute_return_epc_for_insn'. Fixes: fb6883e5809c ("MIPS: microMIPS: Support handling of delay slots.") Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16394/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: math-emu: Prevent wrong ISA mode instruction emulationMaciej W. Rozycki2017-10-121-0/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 13769ebad0c42738831787e27c7c7f982e7da579 upstream. Terminate FPU emulation immediately whenever an ISA mode switch has been observed. This is so that we do not interpret machine code in the wrong mode, for example when a regular MIPS FPU instruction has been placed in a delay slot of a jump that switches into the MIPS16 mode, as with the following code (taken from a GCC test suite case): 00400650 <set_fast_math>: 400650: 3c020100 lui v0,0x100 400654: 03e00008 jr ra 400658: 44c2f800 ctc1 v0,c1_fcsr 40065c: 00000000 nop [...] 004012d0 <__libc_csu_init>: 4012d0: f000 6a02 li v0,2 4012d4: f150 0b1c la v1,3f9430 <_DYNAMIC-0x6df0> 4012d8: f400 3240 sll v0,16 4012dc: e269 addu v0,v1 4012de: 659a move gp,v0 4012e0: f00c 64f6 save a0-a2,48,ra,s0-s1 4012e4: 673c move s1,gp 4012e6: f010 9978 lw v1,-32744(s1) 4012ea: d204 sw v0,16(sp) 4012ec: eb40 jalr v1 4012ee: 653b move t9,v1 4012f0: f010 997c lw v1,-32740(s1) 4012f4: f030 9920 lw s1,-32736(s1) 4012f8: e32f subu v1,s1 4012fa: 326b sra v0,v1,2 4012fc: d206 sw v0,24(sp) 4012fe: 220c beqz v0,401318 <__libc_csu_init+0x48> 401300: 6800 li s0,0 401302: 99e0 lw a3,0(s1) 401304: 4801 addiu s0,1 401306: 960e lw a2,56(sp) 401308: 4904 addiu s1,4 40130a: 950d lw a1,52(sp) 40130c: 940c lw a0,48(sp) 40130e: ef40 jalr a3 401310: 653f move t9,a3 401312: 9206 lw v0,24(sp) 401314: ea0a cmp v0,s0 401316: 61f5 btnez 401302 <__libc_csu_init+0x32> 401318: 6476 restore 48,ra,s0-s1 40131a: e8a0 jrc ra Here `set_fast_math' is called from `40130e' (`40130f' with the ISA bit) and emulation triggers for the CTC1 instruction. As it is in a jump delay slot emulation continues from `401312' (`401313' with the ISA bit). However we have no path to handle MIPS16 FPU code emulation, because there are no MIPS16 FPU instructions. So the default emulation path is taken, interpreting a 32-bit word fetched by `get_user' from `401313' as a regular MIPS instruction, which is: 401313: f5ea0a92 sdc1 $f10,2706(t7) This makes the FPU emulator proceed with the supposed SDC1 instruction and consequently makes the program considered here terminate with SIGSEGV. A similar although less severe issue exists with pure-microMIPS processors in the case where similarly an FPU instruction is emulated in a delay slot of a register jump that (incorrectly) switches into the regular MIPS mode. A subsequent instruction fetch from the jump's target is supposed to cause an Address Error exception, however instead we proceed with regular MIPS FPU emulation. For simplicity then, always terminate the emulation loop whenever a mode change is detected, denoted by an ISA mode bit flip. As from commit 377cb1b6c16a ("MIPS: Disable MIPS16/microMIPS crap for platforms not supporting these ASEs.") the result of `get_isa16_mode' can be hardcoded to 0, so we need to examine the ISA mode bit by hand. This complements commit 102cedc32a6e ("MIPS: microMIPS: Floating point support.") which added JALX decoding to FPU emulation. Fixes: 102cedc32a6e ("MIPS: microMIPS: Floating point support.") Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16393/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Fix mips_atomic_set() with EVAJames Hogan2017-10-121-2/+5
| | | | | | | | | | | | | | | | commit 4915e1b043d6286928207b1f6968197b50407294 upstream. EVA linked loads (LLE) and conditional stores (SCE) should be used on EVA kernels for the MIPS_ATOMIC_SET operation of the sysmips system call, or else the atomic set will apply to the kernel view of the virtual address space (potentially unmapped on EVA kernels) rather than the user view (TLB mapped). Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16151/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Save static registers before sysmipsJames Hogan2017-10-125-4/+10
| | | | | | | | | | | | | | | | | | | | commit 49955d84cd9ccdca5a16a495e448e1a06fad9e49 upstream. The MIPS sysmips system call handler may return directly from the MIPS_ATOMIC_SET case (mips_atomic_set()) to syscall_exit. This path restores the static (callee saved) registers, however they won't have been saved on entry to the system call. Use the save_static_function() macro to create a __sys_sysmips wrapper function which saves the static registers before calling sys_sysmips, so that the correct static register state is restored by syscall_exit. Fixes: f1e39a4a616c ("MIPS: Rewrite sysmips(MIPS_ATOMIC_SET, ...) in C with inline assembler") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16149/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Fix mips_atomic_set() retry conditionJames Hogan2017-10-121-1/+1
| | | | | | | | | | | | | | | | | | | | commit 2ec420b26f7b6ff332393f0bb5a7d245f7ad87f0 upstream. The inline asm retry check in the MIPS_ATOMIC_SET operation of the sysmips system call has been backwards since commit f1e39a4a616c ("MIPS: Rewrite sysmips(MIPS_ATOMIC_SET, ...) in C with inline assembler") merged in v2.6.32, resulting in the non R10000_LLSC_WAR case retrying until the operation was inatomic, before returning the new value that was probably just written multiple times instead of the old value. Invert the branch condition to fix that particular issue. Fixes: f1e39a4a616c ("MIPS: Rewrite sysmips(MIPS_ATOMIC_SET, ...) in C with inline assembler") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16148/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: module: Ensure we always clean up r_mips_hi16_listPaul Burton2017-10-121-12/+16
| | | | | | | | | | | | | | | | | | commit 351b0940d473146923711bc943fc881354a4c1f3 upstream. If we hit an error whilst processing a reloc then we would return early from apply_relocate & potentially not free entries in r_mips_hi16_list, thereby leaking memory. Fix this by ensuring that we always run the code to free r_mipps_hi16_list when errors occur. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Fixes: 861667dc82f5 ("MIPS: Fix race condition in module relocation code.") Fixes: 04211a574641 ("MIPS: Bail on unsupported module relocs") Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/15831/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Bail on unsupported module relocsPaul Burton2017-10-122-6/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | commit 04211a574641e29b529dcc84e75c03d7e9e368cf upstream. When an unsupported reloc is encountered in a module, we currently blindly branch to whatever would be at its entry in the reloc handler function pointer arrays. This may be NULL, or if the unsupported reloc has a type greater than that of the supported reloc with the highest type then we'll dereference some value after the function pointer array & branch to that. The result is at best a kernel oops. Fix this by checking that the reloc type has an entry in the function pointer array (ie. is less than the number of items in the array) and that the handler is non-NULL, returning an error code to fail the module load if no handler is found. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Steven J. Hill <Steven.Hill@imgtec.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> 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/12432/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Avoid accidental raw backtraceJames Hogan2017-09-151-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | commit 854236363370995a609a10b03e35fd3dc5e9e4a1 upstream. Since commit 81a76d7119f6 ("MIPS: Avoid using unwind_stack() with usermode") show_backtrace() invokes the raw backtracer when cp0_status & ST0_KSU indicates user mode to fix issues on EVA kernels where user and kernel address spaces overlap. However this is used by show_stack() which creates its own pt_regs on the stack and leaves cp0_status uninitialised in most of the code paths. This results in the non deterministic use of the raw back tracer depending on the previous stack content. show_stack() deals exclusively with kernel mode stacks anyway, so explicitly initialise regs.cp0_status to KSU_KERNEL (i.e. 0) to ensure we get a useful backtrace. Fixes: 81a76d7119f6 ("MIPS: Avoid using unwind_stack() with usermode") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16656/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Fix IRQ tracing & lockdep when reschedulingPaul Burton2017-09-151-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit d8550860d910c6b7b70f830f59003b33daaa52c9 upstream. When the scheduler sets TIF_NEED_RESCHED & we call into the scheduler from arch/mips/kernel/entry.S we disable interrupts. This is true regardless of whether we reach work_resched from syscall_exit_work, resume_userspace or by looping after calling schedule(). Although we disable interrupts in these paths we don't call trace_hardirqs_off() before calling into C code which may acquire locks, and we therefore leave lockdep with an inconsistent view of whether interrupts are disabled or not when CONFIG_PROVE_LOCKING & CONFIG_DEBUG_LOCKDEP are both enabled. Without tracing this interrupt state lockdep will print warnings such as the following once a task returns from a syscall via syscall_exit_partial with TIF_NEED_RESCHED set: [ 49.927678] ------------[ cut here ]------------ [ 49.934445] WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:3687 check_flags.part.41+0x1dc/0x1e8 [ 49.946031] DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled) [ 49.946355] CPU: 0 PID: 1 Comm: init Not tainted 4.10.0-00439-gc9fd5d362289-dirty #197 [ 49.963505] Stack : 0000000000000000 ffffffff81bb5d6a 0000000000000006 ffffffff801ce9c4 [ 49.974431] 0000000000000000 0000000000000000 0000000000000000 000000000000004a [ 49.985300] ffffffff80b7e487 ffffffff80a24498 a8000000ff160000 ffffffff80ede8b8 [ 49.996194] 0000000000000001 0000000000000000 0000000000000000 0000000077c8030c [ 50.007063] 000000007fd8a510 ffffffff801cd45c 0000000000000000 a8000000ff127c88 [ 50.017945] 0000000000000000 ffffffff801cf928 0000000000000001 ffffffff80a24498 [ 50.028827] 0000000000000000 0000000000000001 0000000000000000 0000000000000000 [ 50.039688] 0000000000000000 a8000000ff127bd0 0000000000000000 ffffffff805509bc [ 50.050575] 00000000140084e0 0000000000000000 0000000000000000 0000000000040a00 [ 50.061448] 0000000000000000 ffffffff8010e1b0 0000000000000000 ffffffff805509bc [ 50.072327] ... [ 50.076087] Call Trace: [ 50.079869] [<ffffffff8010e1b0>] show_stack+0x80/0xa8 [ 50.086577] [<ffffffff805509bc>] dump_stack+0x10c/0x190 [ 50.093498] [<ffffffff8015dde0>] __warn+0xf0/0x108 [ 50.099889] [<ffffffff8015de34>] warn_slowpath_fmt+0x3c/0x48 [ 50.107241] [<ffffffff801c15b4>] check_flags.part.41+0x1dc/0x1e8 [ 50.114961] [<ffffffff801c239c>] lock_is_held_type+0x8c/0xb0 [ 50.122291] [<ffffffff809461b8>] __schedule+0x8c0/0x10f8 [ 50.129221] [<ffffffff80946a60>] schedule+0x30/0x98 [ 50.135659] [<ffffffff80106278>] work_resched+0x8/0x34 [ 50.142397] ---[ end trace 0cb4f6ef5b99fe21 ]--- [ 50.148405] possible reason: unannotated irqs-off. [ 50.154600] irq event stamp: 400463 [ 50.159566] hardirqs last enabled at (400463): [<ffffffff8094edc8>] _raw_spin_unlock_irqrestore+0x40/0xa8 [ 50.171981] hardirqs last disabled at (400462): [<ffffffff8094eb98>] _raw_spin_lock_irqsave+0x30/0xb0 [ 50.183897] softirqs last enabled at (400450): [<ffffffff8016580c>] __do_softirq+0x4ac/0x6a8 [ 50.195015] softirqs last disabled at (400425): [<ffffffff80165e78>] irq_exit+0x110/0x128 Fix this by using the TRACE_IRQS_OFF macro to call trace_hardirqs_off() when CONFIG_TRACE_IRQFLAGS is enabled. This is done before invoking schedule() following the work_resched label because: 1) Interrupts are disabled regardless of the path we take to reach work_resched() & schedule(). 2) Performing the tracing here avoids the need to do it in paths which disable interrupts but don't call out to C code before hitting a path which uses the RESTORE_SOME macro that will call trace_hardirqs_on() or trace_hardirqs_off() as appropriate. We call trace_hardirqs_on() using the TRACE_IRQS_ON macro before calling syscall_trace_leave() for similar reasons, ensuring that lockdep has a consistent view of state after we re-enable interrupts. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/15385/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: pm-cps: Drop manual cache-line alignment of ready_countPaul Burton2017-09-151-8/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 161c51ccb7a6faf45ffe09aa5cf1ad85ccdad503 upstream. We allocate memory for a ready_count variable per-CPU, which is accessed via a cached non-coherent TLB mapping to perform synchronisation between threads within the core using LL/SC instructions. In order to ensure that the variable is contained within its own data cache line we allocate 2 lines worth of memory & align the resulting pointer to a line boundary. This is however unnecessary, since kmalloc is guaranteed to return memory which is at least cache-line aligned (see ARCH_DMA_MINALIGN). Stop the redundant manual alignment. Besides cleaning up the code & avoiding needless work, this has the side effect of avoiding an arithmetic error found by Bryan on 64 bit systems due to the 32 bit size of the former dlinesz. This led the ready_count variable to have its upper 32b cleared erroneously for MIPS64 kernels, causing problems when ready_count was later used on MIPS64 via cpuidle. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Fixes: 3179d37ee1ed ("MIPS: pm-cps: add PM state entry code for CPS systems") Reported-by: Bryan O'Donoghue <bryan.odonoghue@imgtec.com> Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@imgtec.com> Tested-by: Bryan O'Donoghue <bryan.odonoghue@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/15383/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: kprobes: flush_insn_slot should flush only if probe initialisedMarcin Nowakowski2017-09-151-1/+2
| | | | | | | | | | | | | | | | commit 698b851073ddf5a894910d63ca04605e0473414e upstream. When ftrace is used with kprobes, it is possible for a kprobe to contain an invalid location (ie. only initialised to 0 and not to a specific location in the code). Trying to perform a cache flush on such location leads to a crash r4k_flush_icache_range(). Fixes: c1bf207d6ee1 ("MIPS: kprobe: Add support.") Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16296/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: KGDB: Use kernel context for sleeping threadsJames Hogan2017-07-181-15/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Ben Hutchings <ben@decadent.org.uk>
* MIPS: End spinlocks with .insnPaul Burton2017-07-181-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 4b5347a24a0f2d3272032c120664b484478455de upstream. When building for microMIPS we need to ensure that the assembler always knows that there is code at the target of a branch or jump. Recent toolchains will fail to link a microMIPS kernel when this isn't the case due to what it thinks is a branch to non-microMIPS code. mips-mti-linux-gnu-ld kernel/built-in.o: .spinlock.text+0x2fc: Unsupported branch between ISA modes. mips-mti-linux-gnu-ld final link failed: Bad value This is due to inline assembly labels in spinlock.h not being followed by an instruction mnemonic, either due to a .subsection pseudo-op or the end of the inline asm block. Fix this with a .insn direction after such labels. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Signed-off-by: James Hogan <james.hogan@imgtec.com> Reviewed-by: Maciej W. Rozycki <macro@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/15325/ Signed-off-by: James Hogan <james.hogan@imgtec.com> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* mm: larger stack guard gap, between vmasHugh Dickins2017-07-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 1be7107fbe18eed3e319a6c3e83c78254b693acb upstream. Stack guard page is a useful feature to reduce a risk of stack smashing into a different mapping. We have been using a single page gap which is sufficient to prevent having stack adjacent to a different mapping. But this seems to be insufficient in the light of the stack usage in userspace. E.g. glibc uses as large as 64kB alloca() in many commonly used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX] which is 256kB or stack strings with MAX_ARG_STRLEN. This will become especially dangerous for suid binaries and the default no limit for the stack size limit because those applications can be tricked to consume a large portion of the stack and a single glibc call could jump over the guard page. These attacks are not theoretical, unfortunatelly. Make those attacks less probable by increasing the stack guard gap to 1MB (on systems with 4k pages; but make it depend on the page size because systems with larger base pages might cap stack allocations in the PAGE_SIZE units) which should cover larger alloca() and VLA stack allocations. It is obviously not a full fix because the problem is somehow inherent, but it should reduce attack space a lot. One could argue that the gap size should be configurable from userspace, but that can be done later when somebody finds that the new 1MB is wrong for some special case applications. For now, add a kernel command line option (stack_guard_gap) to specify the stack gap size (in page units). Implementation wise, first delete all the old code for stack guard page: because although we could get away with accounting one extra page in a stack vma, accounting a larger gap can break userspace - case in point, a program run with "ulimit -S -v 20000" failed when the 1MB gap was counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK and strict non-overcommit mode. Instead of keeping gap inside the stack vma, maintain the stack guard gap as a gap between vmas: using vm_start_gap() in place of vm_start (or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few places which need to respect the gap - mainly arch_get_unmapped_area(), and and the vma tree's subtree_gap support for that. Original-patch-by: Oleg Nesterov <oleg@redhat.com> Original-patch-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Tested-by: Helge Deller <deller@gmx.de> # parisc Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [Hugh Dickins: Backported to 3.16] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: BCM47XX: Fix button inversion for Asus WL-500WMirko Parthey2017-06-051-2/+8
| | | | | | | | | | | | | | | | commit bdfdaf1a016ef09cb941f2edad485a713510b8d5 upstream. The Asus WL-500W buttons are active high, but the software treats them as active low. Fix the inverted logic. Fixes: 3be972556fa1 ("MIPS: BCM47XX: Import buttons database from OpenWrt") Signed-off-by: Mirko Parthey <mirko.parthey@web.de> Acked-by: Rafał Miłecki <rafal@milecki.pl> Cc: Hauke Mehrtens <hauke@hauke-m.de> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/15295/ Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: ip27: Disable qlge driver in defconfigArnd Bergmann2017-06-051-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | commit b617649468390713db1515ea79fc772d2eb897a8 upstream. One of the last remaining failures in kernelci.org is for a gcc bug: drivers/net/ethernet/qlogic/qlge/qlge_main.c:4819:1: error: insn does not satisfy its constraints: drivers/net/ethernet/qlogic/qlge/qlge_main.c:4819:1: internal compiler error: in extract_constrain_insn, at recog.c:2190 This is apparently broken in gcc-6 but fixed in gcc-7, and I cannot reproduce the problem here. However, it is clear that ip27_defconfig does not actually need this driver as the platform has only PCI-X but not PCIe, and the qlge adapter in turn is PCIe-only. The driver was originally enabled in 2010 along with lots of other drivers. Fixes: 59d302b342e5 ("MIPS: IP27: Make defconfig useful again.") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/15197/ Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: OCTEON: Fix copy_from_user fault handling for large buffersJames Cowgill2017-06-051-8/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 884b426917e4b3c85f33b382c792a94305dfdd62 upstream. If copy_from_user is called with a large buffer (>= 128 bytes) and the userspace buffer refers partially to unreadable memory, then it is possible for Octeon's copy_from_user to report the wrong number of bytes have been copied. In the case where the buffer size is an exact multiple of 128 and the fault occurs in the last 64 bytes, copy_from_user will report that all the bytes were copied successfully but leave some garbage in the destination buffer. The bug is in the main __copy_user_common loop in octeon-memcpy.S where in the middle of the loop, src and dst are incremented by 128 bytes. The l_exc_copy fault handler is used after this but that assumes that "src < THREAD_BUADDR($28)". This is not the case if src has already been incremented. Fix by adding an extra fault handler which rewinds the src and dst pointers 128 bytes before falling though to l_exc_copy. Thanks to the pwritev test from the strace test suite for originally highlighting this bug! Fixes: 5b3b16880f40 ("MIPS: Add Cavium OCTEON processor support ...") Signed-off-by: James Cowgill <James.Cowgill@imgtec.com> Acked-by: David Daney <david.daney@cavium.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14978/ Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Fix special case in 64 bit IP checksumming.Ralf Baechle2017-06-051-0/+2
| | | | | | | | | | | | | | | | commit 66fd848cadaa6be974a8c780fbeb328f0af4d3bd upstream. For certain arguments such as saddr = 0xc0a8fd60, daddr = 0xc0a8fda1, len = 80, proto = 17, sum = 0x7eae049d there will be a carry when folding the intermediate 64 bit checksum to 32 bit but the code doesn't add the carry back to the one's complement sum, thus an incorrect result will be generated. Reported-by: Mark Zhang <bomb.zhang@gmail.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Reviewed-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: 'make -s' should be silentArnd Bergmann2017-06-051-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | commit 8c9b23ffb3f92ffa4cbe37b1bab4542586e0bfd1 upstream. A clean mips64 build produces no output except for two lines: Checking missing-syscalls for N32 Checking missing-syscalls for O32 On other architectures, there is no output at all, so let's do the same here for the sake of build testing. The 'kecho' macro is used to print the message on a normal build but skip it with 'make -s'. Fixes: e48ce6b8df5b ("[MIPS] Simplify missing-syscalls for N32 and O32") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Huacai Chen <chenhc@lemote.com> Cc: Maarten ter Huurne <maarten@treewalker.org> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/15040/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Netlogic: Fix assembler warning from smpboot.SPaul Burton2017-06-051-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | commit a8b3b0c94ac282628f0668d1366239a3fa72dc9d upstream. The netlogic platform can be built for either MIPS32 or MIPS64, and when built for MIPS32 (as by nlm_xlr_defconfig) the use of the dla pseudo-instruction leads to warnings such as the following from recent versions of the GNU assembler: arch/mips/netlogic/common/smpboot.S: Assembler messages: arch/mips/netlogic/common/smpboot.S:62: Warning: dla used to load 32-bit register; recommend using la instead arch/mips/netlogic/common/smpboot.S:63: Warning: dla used to load 32-bit register; recommend using la instead Avoid these warnings by using the PTR_LA macro to make use of the appropriate la or dla pseudo-instruction for the build. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Fixes: 66d29985fab8 ("MIPS: Netlogic: Merge some of XLR/XLP wakup code") Cc: James Hogan <james.hogan@imgtec.com> Cc: Jayachandran C <jchandra@broadcom.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/14185/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Handle microMIPS jumps in the same way as MIPS32/MIPS64 jumpsPaul Burton2017-06-051-0/+2
| | | | | | | | | | | | | | | | | | 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: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Calculate microMIPS ra properly when unwinding the stackPaul Burton2017-06-051-20/+63
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Fix is_jump_ins() handling of 16b microMIPS instructionsPaul Burton2017-06-051-3/+8
| | | | | | | | | | | | | | | | 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: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Fix get_frame_info() handling of microMIPS function sizePaul Burton2017-06-051-7/+5
| | | | | | | | | | | | | | | | | | | | | | | 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: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Prevent unaligned accesses during stack unwindingPaul Burton2017-06-051-35/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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> [bwh: Backported to 3.16: old code had extra parentheses] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Clear ISA bit correctly in get_frame_info()Paul Burton2017-06-051-5/+2
| | | | | | | | | | | | | | | | | | | | | | | | 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: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Zero variable read by get_user / __get_user in case of an error.Ralf Baechle2017-04-041-1/+4
| | | | | | | | | | commit 640465bda58c7078725201be7430c31a349121e9 upstream. This wasn't happening in all cases. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Arnd Bergmann <arnd@arndb.de>
* MIPS: ralink: Cosmetic change to prom_init().John Crispin2017-04-041-5/+4
| | | | | | | | | | | | | | | commit 9c48568b3692f1a56cbf1935e4eea835e6b185b1 upstream. Over the years the code has been changed various times leading to argc/argv being defined in a different function to where we actually use the variables. Clean this up by moving them to prom_init_cmdline(). Signed-off-by: John Crispin <john@phrozen.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14902/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Arnd Bergmann <arnd@arndb.de>
* MIPS: wrap cfcmsa & ctcmsa accesses for toolchains with MSA supportPaul Burton2017-04-041-4/+20
| | | | | | | | | | | | | | | | | | | | | | | | | commit e1bebbab1eaecac77d77033010b5e0f51b737e64 upstream. Uses of the cfcmsa & ctcmsa instructions were not being wrapped by a macro in the case where the toolchain supports MSA, since the arguments exactly match a typical use of the instructions. However using current toolchains this leads to errors such as: arch/mips/kernel/genex.S:437: Error: opcode not supported on this processor: mips32r2 (mips32r2) `cfcmsa $5,1' Thus uses of the instructions must be in the context of a ".set msa" directive, however doing that from the users of the instructions would be messy due to the possibility that the toolchain does not support MSA. Fix this by renaming the macros (prepending an underscore) in order to avoid recursion when attempting to emit the instructions, and provide implementations for the TOOLCHAIN_SUPPORTS_MSA case which ".set msa" as appropriate. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9163/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: remove MSA macro recursionPaul Burton2017-04-041-3/+31
| | | | | | | | | | | | | | | | | | | | | | | | commit a3a49810c55e3489dfb5d72a9b2e41ab1db9ffb9 upstream. Recursive macros made the code more concise & worked great for the case where the toolchain doesn't support MSA. However, with toolchains which do support MSA they lead to build failures such as: arch/mips/kernel/r4k_switch.S: Assembler messages: arch/mips/kernel/r4k_switch.S:148: Error: invalid operands `insert.w $w(0+1)[2],$1' arch/mips/kernel/r4k_switch.S:148: Error: invalid operands `insert.w $w(0+1)[3],$1' arch/mips/kernel/r4k_switch.S:148: Error: invalid operands `insert.w $w((0+1)+1)[2],$1' arch/mips/kernel/r4k_switch.S:148: Error: invalid operands `insert.w $w((0+1)+1)[3],$1' ... Drop the recursion from msa_init_all_upper invoking the msa_init_upper macro explicitly for each vector register. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9162/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: assume at as source/dest of MSA copy/insert instructionsPaul Burton2017-04-041-16/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | commit f23ce3883a30743a5b779dc6fb90ca8620688a23 upstream. Assuming at ($1) as the source or destination register of copy or insert instructions: - Simplifies the macros providing those instructions for toolchains without MSA support. - Avoids an unnecessary move instruction when at is used as the source or destination register anyway. - Is sufficient for the uses to be introduced in the kernel by a subsequent patch. Note that due to a patch ordering snafu on my part this also fixes the currently broken build with MSA support enabled. The build has been broken since commit c9017757c532 "MIPS: init upper 64b of vector registers when MSA is first used", which this patch should have preceeded. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9161/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Push .set mips64r* into the functions needing itPaul Burton2017-04-042-9/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 631afc65e8f4f845945ef9e90236d10cee601498 upstream. The {save,restore}_fp_context{,32} functions require that the assembler allows the use of sdc instructions on any FP register, and this is acomplished by setting the arch to mips64r2 or mips64r6 (using MIPS_ISA_ARCH_LEVEL_RAW). However this has the effect of enabling the assembler to use mips64 instructions in the expansion of pseudo-instructions. This was done in the (now-reverted) commit eec43a224cf1 "MIPS: Save/restore MSA context around signals" which led to my mistakenly believing that there was an assembler bug, when in reality the assembler was just emitting mips64 instructions. Avoid the issue for future commits which will add code to r4k_fpu.S by pushing the .set MIPS_ISA_ARCH_LEVEL_RAW directives into the functions that require it, and remove the spurious assertion declaring the assembler bug. Signed-off-by: Paul Burton <paul.burton@imgtec.com> [james.hogan@imgtec.com: Rebase on v4.0-rc1 and reword commit message to reflect use of MIPS_ISA_ARCH_LEVEL_RAW] Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9612/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> [bwh: Backported to 3.16: in r4k_fpu.S, keep using arch=r4000] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: traps: Fix inline asm ctc1 missing .set hardfloatJames Hogan2017-04-041-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | commit d76e9b9fc5de7e8fc4fd0e72a94e8c723929ffea upstream. Commit 842dfc11ea9a ("MIPS: Fix build with binutils 2.24.51+") in v3.18 enabled -msoft-float and sprinkled ".set hardfloat" where necessary to use FP instructions. However it missed enable_restore_fp_context() which since v3.17 does a ctc1 with inline assembly, causing the following assembler errors on Mentor's 2014.05 toolchain: {standard input}: Assembler messages: {standard input}:2913: Error: opcode not supported on this processor: mips32r2 (mips32r2) `ctc1 $2,$31' scripts/Makefile.build:257: recipe for target 'arch/mips/kernel/traps.o' failed Fix that to use the new write_32bit_cp1_register() macro so that ".set hardfloat" is automatically added when -msoft-float is in use. Fixes 842dfc11ea9a ("MIPS: Fix build with binutils 2.24.51+") Signed-off-by: James Hogan <james.hogan@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/9173/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: mipsregs.h: Add write_32bit_cp1_register()James Hogan2017-04-041-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | commit 5e32033e14ca9c7f7341cb383f5a05699b0b5382 upstream. Add a write_32bit_cp1_register() macro to compliment the read_32bit_cp1_register() macro. This is to abstract whether .set hardfloat needs to be used based on GAS_HAS_SET_HARDFLOAT. The implementation of _read_32bit_cp1_register() .sets mips1 due to failure of gas v2.19 to assemble cfc1 for Octeon (see commit 25c300030016 ("MIPS: Override assembler target architecture for octeon.")). I haven't copied this over to _write_32bit_cp1_register() as I'm uncertain whether it applies to ctc1 too, or whether anybody cares about that version of binutils any longer. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@imgtec.com> Cc: David Daney <david.daney@cavium.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9172/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: Fix build with binutils 2.24.51+Manuel Lauss2017-04-0414-17/+118
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 842dfc11ea9a21f9825167c8a4f2834b205b0a79 upstream. Starting with version 2.24.51.20140728 MIPS binutils complain loudly about mixing soft-float and hard-float object files, leading to this build failure since GCC is invoked with "-msoft-float" on MIPS: {standard input}: Warning: .gnu_attribute 4,3 requires `softfloat' LD arch/mips/alchemy/common/built-in.o mipsel-softfloat-linux-gnu-ld: Warning: arch/mips/alchemy/common/built-in.o uses -msoft-float (set by arch/mips/alchemy/common/prom.o), arch/mips/alchemy/common/sleeper.o uses -mhard-float To fix this, we detect if GAS is new enough to support "-msoft-float" command option, and if it does, we can let GCC pass it to GAS; but then we also need to sprinkle the files which make use of floating point registers with the necessary ".set hardfloat" directives. Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com> Cc: Linux-MIPS <linux-mips@linux-mips.org> Cc: Matthew Fortune <Matthew.Fortune@imgtec.com> Cc: Markos Chandras <Markos.Chandras@imgtec.com> Cc: Maciej W. Rozycki <macro@linux-mips.org> Patchwork: https://patchwork.linux-mips.org/patch/8355/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Arnd Bergmann <arnd@arndb.de>
* MIPS: init upper 64b of vector registers when MSA is first usedPaul Burton2017-04-044-9/+56
| | | | | | | | | | | | | | | | | | | | | | | commit c9017757c532d48bf43d6e7d3b7282443ad4207b upstream. When a task first makes use of MSA we need to ensure that the upper 64b of the vector registers are set to some value such that no information can be leaked to it from the previous task to use MSA context on the CPU. The architecture formerly specified that these bits would be cleared to 0 when a scalar FP instructions wrote to the aliased FP registers, which would have implicitly handled this as the kernel restored scalar FP context. However more recent versions of the specification now state that the value of the bits in such cases is unpredictable. Initialise them explictly to be sure, and set all the bits to 1 rather than 0 for consistency with the least significant 64b. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7497/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Arnd Bergmann <arnd@arndb.de>
* MIPS: save/disable MSA in lose_fpuPaul Burton2017-04-041-3/+12
| | | | | | | | | | | | | | | | commit 33c771ba5c5d067f85a5a6c4b11047219b5b8f4e upstream. The kernel depends upon MSA never being enabled when the FPU is not, a condition which is currently violated in a few places (whilst saving sigcontext, following mips_cpu_save). Catch all the problem cases by disabling MSA in lose_fpu, after saving context if necessary. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7302/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Arnd Bergmann <arnd@arndb.de>
* MIPS: preserve scalar FP CSR when switching vector contextPaul Burton2017-04-042-1/+8
| | | | | | | | | | | | | | | | | | commit b83406735a4ae0aff4b614664d6a64a0fd6b9917 upstream. Switching the vector context implicitly saves & restores the state of the aliased scalar FP data registers, however the scalar FP control & status register is distinct from the MSA control & status register. In order to allow scalar FP to function correctly in programs using MSA, the scalar CSR needs to be saved & restored along with the MSA vector context. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7301/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Arnd Bergmann <arnd@arndb.de>
* MIPS: save/restore MSACSR register on context switchPaul Burton2017-04-042-0/+12
| | | | | | | | | | | | | | | commit f7a46fa7bb0047d3e226702a0c4b786862fe6843 upstream. I added a field for the MSACSR register in struct mips_fpu_struct, but never actually made use of it... This is a clear bug. Save and restore the MSACSR register along with the vector registers. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7300/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Arnd Bergmann <arnd@arndb.de>
* MIPS: allow msa.h to be included in assembly filesPaul Burton2017-04-041-9/+13
| | | | | | | | | | | | | commit 558155a0a731b4f56846559a57ca7ca921230497 upstream. Just #ifdef away the C functions when included from an assembly file, as will be done in a following commit. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7299/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* KVM: MIPS: Flush KVM entry code from icache globallyJames Hogan2017-03-161-2/+2
| | | | | | | | | | | | | | | | | commit 32eb12a6c11034867401d56b012e3c15d5f8141e upstream. Flush the KVM entry code from the icache on all CPUs, not just the one that built the entry code. 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>
* KVM: MIPS: Precalculate MMIO load resume PCJames Hogan2017-02-232-13/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | commit e1e575f6b026734be3b1f075e780e91ab08ca541 upstream. The advancing of the PC when completing an MMIO load is done before re-entering the guest, i.e. before restoring the guest ASID. However if the load is in a branch delay slot it may need to access guest code to read the prior branch instruction. This isn't safe in TLB mapped code at the moment, nor in the future when we'll access unmapped guest segments using direct user accessors too, as it could read the branch from host user memory instead. Therefore calculate the resume PC in advance while we're still in the right context and save it in the new vcpu->arch.io_pc (replacing the no longer needed vcpu->arch.pending_load_cause), and restore it on MMIO completion. 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: Paolo Bonzini <pbonzini@redhat.com> [bwh: Backported to 3.16: adjust filename, context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: KVM: Fix unused variable build warningNicholas Mc Guire2017-02-231-6/+0
| | | | | | | | | | | | | | | | | | | | | commit 5f508c43a7648baa892528922402f1e13f258bd4 upstream. As kvm_mips_complete_mmio_load() did not yet modify PC at this point as James Hogans <james.hogan@imgtec.com> explained the curr_pc variable and the comments along with it can be dropped. Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org> Link: http://lkml.org/lkml/2015/5/8/422 Cc: Gleb Natapov <gleb@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/9993/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> [bwh: Backported to 3.16: adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* KVM: MIPS: Make ERET handle ERL before EXLJames Hogan2017-02-231-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | commit ede5f3e7b54a4347be4d8525269eae50902bd7cd upstream. The ERET instruction to return from exception is used for returning from exception level (Status.EXL) and error level (Status.ERL). If both bits are set however we should be returning from ERL first, as ERL can interrupt EXL, for example when an NMI is taken. KVM however checks EXL first. Fix the order of the checks to match the pseudocode in the instruction set manual. 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: Paolo Bonzini <pbonzini@redhat.com> [bwh: Backported to 3.16: adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* MIPS: ptrace: Fix regs_return_value for kernel contextMarcin Nowakowski2017-02-231-1/+1
| | | | | | | | | | | | | | | | | commit 74f1077b5b783e7bf4fa3007cefdc8dbd6c07518 upstream. Currently regs_return_value always negates reg[2] if it determines the syscall has failed, but when called in kernel context this check is invalid and may result in returning a wrong value. This fixes errors reported by CONFIG_KPROBES_SANITY_TEST Fixes: d7e7528bcd45 ("Audit: push audit success and retcode into arch ptrace.h") Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14381/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
generated by cgit v1.2.3 (git 2.46.0) at 2025-04-23 06:33:48 +0000