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2021-08-24riscv: Ensure the value of FP registers in the core dump file is up to dateVincent Chen
The value of FP registers in the core dump file comes from the thread.fstate. However, kernel saves the FP registers to the thread.fstate only before scheduling out the process. If no process switch happens during the exception handling process, kernel will not have a chance to save the latest value of FP registers to thread.fstate. It will cause the value of FP registers in the core dump file may be incorrect. To solve this problem, this patch force lets kernel save the FP register into the thread.fstate if the target task_struct equals the current. Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Reviewed-by: Jisheng Zhang <jszhang@kernel.org> Fixes: b8c8a9590e4f ("RISC-V: Add FP register ptrace support for gdb.") Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-08-20riscv: Fix a number of free'd resources in init_resources()Petr Pavlu
Function init_resources() allocates a boot memory block to hold an array of resources which it adds to iomem_resource. The array is filled in from its end and the function then attempts to free any unused memory at the beginning. The problem is that size of the unused memory is incorrectly calculated and this can result in releasing memory which is in use by active resources. Their data then gets corrupted later when the memory is reused by a different part of the system. Fix the size of the released memory to correctly match the number of unused resource entries. Fixes: ffe0e5261268 ("RISC-V: Improve init_resources()") Signed-off-by: Petr Pavlu <petr.pavlu@suse.com> Reviewed-by: Sunil V L <sunilvl@ventanamicro.com> Acked-by: Nick Kossifidis <mick@ics.forth.gr> Tested-by: Sunil V L <sunilvl@ventanamicro.com> Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-08-12riscv: kexec: do not add '-mno-relax' flag if compiler doesn't support itChangbin Du
The RISC-V special option '-mno-relax' which to disable linker relaxations is supported by GCC8+. For GCC7 and lower versions do not support this option. Fixes: fba8a8674f68 ("RISC-V: Add kexec support") Signed-off-by: Changbin Du <changbin.du@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-07-24riscv: stacktrace: Fix NULL pointer dereferenceJisheng Zhang
When CONFIG_FRAME_POINTER=y, calling dump_stack() can always trigger NULL pointer dereference panic similar as below: [ 0.396060] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.13.0-rc5+ #47 [ 0.396692] Hardware name: riscv-virtio,qemu (DT) [ 0.397176] Call Trace: [ 0.398191] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000960 [ 0.399487] Oops [#1] [ 0.399739] Modules linked in: [ 0.400135] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.13.0-rc5+ #47 [ 0.400570] Hardware name: riscv-virtio,qemu (DT) [ 0.400926] epc : walk_stackframe+0xc4/0xdc [ 0.401291] ra : dump_backtrace+0x30/0x38 [ 0.401630] epc : ffffffff80004922 ra : ffffffff8000496a sp : ffffffe000f3bd00 [ 0.402115] gp : ffffffff80cfdcb8 tp : ffffffe000f30000 t0 : ffffffff80d0b0cf [ 0.402602] t1 : ffffffff80d0b0c0 t2 : 0000000000000000 s0 : ffffffe000f3bd60 [ 0.403071] s1 : ffffffff808bc2e8 a0 : 0000000000001000 a1 : 0000000000000000 [ 0.403448] a2 : ffffffff803d7088 a3 : ffffffff808bc2e8 a4 : 6131725dbc24d400 [ 0.403820] a5 : 0000000000001000 a6 : 0000000000000002 a7 : ffffffffffffffff [ 0.404226] s2 : 0000000000000000 s3 : 0000000000000000 s4 : 0000000000000000 [ 0.404634] s5 : ffffffff803d7088 s6 : ffffffff808bc2e8 s7 : ffffffff80630650 [ 0.405085] s8 : ffffffff80912a80 s9 : 0000000000000008 s10: ffffffff804000fc [ 0.405388] s11: 0000000000000000 t3 : 0000000000000043 t4 : ffffffffffffffff [ 0.405616] t5 : 000000000000003d t6 : ffffffe000f3baa8 [ 0.405793] status: 0000000000000100 badaddr: 0000000000000960 cause: 000000000000000d [ 0.406135] [<ffffffff80004922>] walk_stackframe+0xc4/0xdc [ 0.407032] [<ffffffff8000496a>] dump_backtrace+0x30/0x38 [ 0.407797] [<ffffffff803d7100>] show_stack+0x40/0x4c [ 0.408234] [<ffffffff803d9e5c>] dump_stack+0x90/0xb6 [ 0.409019] [<ffffffff8040423e>] ptdump_init+0x20/0xc4 [ 0.409681] [<ffffffff800015b6>] do_one_initcall+0x4c/0x226 [ 0.410110] [<ffffffff80401094>] kernel_init_freeable+0x1f4/0x258 [ 0.410562] [<ffffffff803dba88>] kernel_init+0x22/0x148 [ 0.410959] [<ffffffff800029e2>] ret_from_exception+0x0/0x14 [ 0.412241] ---[ end trace b2ab92c901b96251 ]--- [ 0.413099] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b The reason is the task is NULL when we finally call walk_stackframe() the NULL is passed from __dump_stack(): |static void __dump_stack(void) |{ | dump_stack_print_info(KERN_DEFAULT); | show_stack(NULL, NULL, KERN_DEFAULT); |} Fix this issue by checking "task == NULL" case in walk_stackframe(). Fixes: eac2f3059e02 ("riscv: stacktrace: fix the riscv stacktrace when CONFIG_FRAME_POINTER enabled") Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Atish Patra <atish.patra@wdc.com> Tested-by: Wende Tan <twd2.me@gmail.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-07-23riscv: stacktrace: pin the task's stack in get_wchanJisheng Zhang
Pin the task's stack before calling walk_stackframe() in get_wchan(). This can fix the panic as reported by Andreas when CONFIG_VMAP_STACK=y: [ 65.609696] Unable to handle kernel paging request at virtual address ffffffd0003bbde8 [ 65.610460] Oops [#1] [ 65.610626] Modules linked in: virtio_blk virtio_mmio rtc_goldfish btrfs blake2b_generic libcrc32c xor raid6_pq sg dm_multipath dm_mod scsi_dh_rdac scsi_dh_emc scsi_dh_alua efivarfs [ 65.611670] CPU: 2 PID: 1 Comm: systemd Not tainted 5.14.0-rc1-1.g34fe32a-default #1 openSUSE Tumbleweed (unreleased) c62f7109153e5a0897ee58ba52393ad99b070fd2 [ 65.612334] Hardware name: riscv-virtio,qemu (DT) [ 65.613008] epc : get_wchan+0x5c/0x88 [ 65.613334] ra : get_wchan+0x42/0x88 [ 65.613625] epc : ffffffff800048a4 ra : ffffffff8000488a sp : ffffffd00021bb90 [ 65.614008] gp : ffffffff817709f8 tp : ffffffe07fe91b80 t0 : 00000000000001f8 [ 65.614411] t1 : 0000000000020000 t2 : 0000000000000000 s0 : ffffffd00021bbd0 [ 65.614818] s1 : ffffffd0003bbdf0 a0 : 0000000000000001 a1 : 0000000000000002 [ 65.615237] a2 : ffffffff81618008 a3 : 0000000000000000 a4 : 0000000000000000 [ 65.615637] a5 : ffffffd0003bc000 a6 : 0000000000000002 a7 : ffffffe27d370000 [ 65.616022] s2 : ffffffd0003bbd90 s3 : ffffffff8071a81e s4 : 0000000000003fff [ 65.616407] s5 : ffffffffffffc000 s6 : 0000000000000000 s7 : ffffffff81618008 [ 65.616845] s8 : 0000000000000001 s9 : 0000000180000040 s10: 0000000000000000 [ 65.617248] s11: 000000000000016b t3 : 000000ff00000000 t4 : 0c6aec92de5e3fd7 [ 65.617672] t5 : fff78f60608fcfff t6 : 0000000000000078 [ 65.618088] status: 0000000000000120 badaddr: ffffffd0003bbde8 cause: 000000000000000d [ 65.618621] [<ffffffff800048a4>] get_wchan+0x5c/0x88 [ 65.619008] [<ffffffff8022da88>] do_task_stat+0x7a2/0xa46 [ 65.619325] [<ffffffff8022e87e>] proc_tgid_stat+0xe/0x16 [ 65.619637] [<ffffffff80227dd6>] proc_single_show+0x46/0x96 [ 65.619979] [<ffffffff801ccb1e>] seq_read_iter+0x190/0x31e [ 65.620341] [<ffffffff801ccd70>] seq_read+0xc4/0x104 [ 65.620633] [<ffffffff801a6bfe>] vfs_read+0x6a/0x112 [ 65.620922] [<ffffffff801a701c>] ksys_read+0x54/0xbe [ 65.621206] [<ffffffff801a7094>] sys_read+0xe/0x16 [ 65.621474] [<ffffffff8000303e>] ret_from_syscall+0x0/0x2 [ 65.622169] ---[ end trace f24856ed2b8789c5 ]--- [ 65.622832] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-07-09Merge tag 'riscv-for-linus-5.14-mw0' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V updates from Palmer Dabbelt: "We have a handful of new features for 5.14: - Support for transparent huge pages. - Support for generic PCI resources mapping. - Support for the mem= kernel parameter. - Support for KFENCE. - A handful of fixes to avoid W+X mappings in the kernel. - Support for VMAP_STACK based overflow detection. - An optimized copy_{to,from}_user" * tag 'riscv-for-linus-5.14-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (37 commits) riscv: xip: Fix duplicate included asm/pgtable.h riscv: Fix PTDUMP output now BPF region moved back to module region riscv: __asm_copy_to-from_user: Optimize unaligned memory access and pipeline stall riscv: add VMAP_STACK overflow detection riscv: ptrace: add argn syntax riscv: mm: fix build errors caused by mk_pmd() riscv: Introduce structure that group all variables regarding kernel mapping riscv: Map the kernel with correct permissions the first time riscv: Introduce set_kernel_memory helper riscv: Enable KFENCE for riscv64 RISC-V: Use asm-generic for {in,out}{bwlq} riscv: add ASID-based tlbflushing methods riscv: pass the mm_struct to __sbi_tlb_flush_range riscv: Add mem kernel parameter support riscv: Simplify xip and !xip kernel address conversion macros riscv: Remove CONFIG_PHYS_RAM_BASE_FIXED riscv: Only initialize swiotlb when necessary riscv: fix typo in init.c riscv: Cleanup unused functions riscv: mm: Use better bitmap_zalloc() ...
2021-07-08riscv: convert to setup_initial_init_mm()Kefeng Wang
Use setup_initial_init_mm() helper to simplify code. Link: https://lkml.kernel.org/r/20210608083418.137226-13-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-06riscv: xip: Fix duplicate included asm/pgtable.hJiapeng Chong
Clean up the following includecheck warning: ./arch/riscv/kernel/vmlinux-xip.lds.S: asm/pgtable.h is included more than once. No functional change. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-07-06riscv: add VMAP_STACK overflow detectionTong Tiangen
This patch adds stack overflow detection to riscv, usable when CONFIG_VMAP_STACK=y. Overflow is detected in kernel exception entry(kernel/entry.S), if the kernel stack is overflow and been detected, the overflow handler is invoked on a per-cpu overflow stack. This approach preserves GPRs and the original exception information. The overflow detect is performed before any attempt is made to access the stack and the principle of stack overflow detection: kernel stacks are aligned to double their size, enabling overflow to be detected with a single bit test. For example, a 16K stack is aligned to 32K, ensuring that bit 14 of the SP must be zero. On an overflow (or underflow), this bit is flipped. Thus, overflow (of less than the size of the stack) can be detected by testing whether this bit is set. This gives us a useful error message on stack overflow, as can be trigger with the LKDTM overflow test: [ 388.053267] lkdtm: Performing direct entry EXHAUST_STACK [ 388.053663] lkdtm: Calling function with 1024 frame size to depth 32 ... [ 388.054016] lkdtm: loop 32/32 ... [ 388.054186] lkdtm: loop 31/32 ... [ 388.054491] lkdtm: loop 30/32 ... [ 388.054672] lkdtm: loop 29/32 ... [ 388.054859] lkdtm: loop 28/32 ... [ 388.055010] lkdtm: loop 27/32 ... [ 388.055163] lkdtm: loop 26/32 ... [ 388.055309] lkdtm: loop 25/32 ... [ 388.055481] lkdtm: loop 24/32 ... [ 388.055653] lkdtm: loop 23/32 ... [ 388.055837] lkdtm: loop 22/32 ... [ 388.056015] lkdtm: loop 21/32 ... [ 388.056188] lkdtm: loop 20/32 ... [ 388.058145] Insufficient stack space to handle exception! [ 388.058153] Task stack: [0xffffffd014260000..0xffffffd014264000] [ 388.058160] Overflow stack: [0xffffffe1f8d2c220..0xffffffe1f8d2d220] [ 388.058168] CPU: 0 PID: 89 Comm: bash Not tainted 5.12.0-rc8-dirty #90 [ 388.058175] Hardware name: riscv-virtio,qemu (DT) [ 388.058187] epc : number+0x32/0x2c0 [ 388.058247] ra : vsnprintf+0x2ae/0x3f0 [ 388.058255] epc : ffffffe0002d38f6 ra : ffffffe0002d814e sp : ffffffd01425ffc0 [ 388.058263] gp : ffffffe0012e4010 tp : ffffffe08014da00 t0 : ffffffd0142606e8 [ 388.058271] t1 : 0000000000000000 t2 : 0000000000000000 s0 : ffffffd014260070 [ 388.058303] s1 : ffffffd014260158 a0 : ffffffd01426015e a1 : ffffffd014260158 [ 388.058311] a2 : 0000000000000013 a3 : ffff0a01ffffff10 a4 : ffffffe000c398e0 [ 388.058319] a5 : 511b02ec65f3e300 a6 : 0000000000a1749a a7 : 0000000000000000 [ 388.058327] s2 : ffffffff000000ff s3 : 00000000ffff0a01 s4 : ffffffe0012e50a8 [ 388.058335] s5 : 0000000000ffff0a s6 : ffffffe0012e50a8 s7 : ffffffe000da1cc0 [ 388.058343] s8 : ffffffffffffffff s9 : ffffffd0142602b0 s10: ffffffd0142602a8 [ 388.058351] s11: ffffffd01426015e t3 : 00000000000f0000 t4 : ffffffffffffffff [ 388.058359] t5 : 000000000000002f t6 : ffffffd014260158 [ 388.058366] status: 0000000000000100 badaddr: ffffffd01425fff8 cause: 000000000000000f [ 388.058374] Kernel panic - not syncing: Kernel stack overflow [ 388.058381] CPU: 0 PID: 89 Comm: bash Not tainted 5.12.0-rc8-dirty #90 [ 388.058387] Hardware name: riscv-virtio,qemu (DT) [ 388.058393] Call Trace: [ 388.058400] [<ffffffe000004944>] walk_stackframe+0x0/0xce [ 388.058406] [<ffffffe0006f0b28>] dump_backtrace+0x38/0x46 [ 388.058412] [<ffffffe0006f0b46>] show_stack+0x10/0x18 [ 388.058418] [<ffffffe0006f3690>] dump_stack+0x74/0x8e [ 388.058424] [<ffffffe0006f0d52>] panic+0xfc/0x2b2 [ 388.058430] [<ffffffe0006f0acc>] print_trace_address+0x0/0x24 [ 388.058436] [<ffffffe0002d814e>] vsnprintf+0x2ae/0x3f0 [ 388.058956] SMP: stopping secondary CPUs Signed-off-by: Tong Tiangen <tongtiangen@huawei.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-07-05riscv: Introduce structure that group all variables regarding kernel mappingAlexandre Ghiti
We have a lot of variables that are used to hold kernel mapping addresses, offsets between physical and virtual mappings and some others used for XIP kernels: they are all defined at different places in mm/init.c, so group them into a single structure with, for some of them, more explicit and concise names. Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-06-30Merge branch 'riscv-wx-mappings' into for-nextPalmer Dabbelt
This contains both the short-term fix for the W+X boot mappings and the larger cleanup. * riscv-wx-mappings: riscv: Map the kernel with correct permissions the first time riscv: Introduce set_kernel_memory helper riscv: Simplify xip and !xip kernel address conversion macros riscv: Remove CONFIG_PHYS_RAM_BASE_FIXED riscv: mm: Fix W+X mappings at boot
2021-06-30riscv: Map the kernel with correct permissions the first timeAlexandre Ghiti
For 64-bit kernels, we map all the kernel with write and execute permissions and afterwards remove writability from text and executability from data. For 32-bit kernels, the kernel mapping resides in the linear mapping, so we map all the linear mapping as writable and executable and afterwards we remove those properties for unused memory and kernel mapping as described above. Change this behavior to directly map the kernel with correct permissions and avoid going through the whole mapping to fix the permissions. At the same time, this fixes an issue introduced by commit 2bfc6cd81bd1 ("riscv: Move kernel mapping outside of linear mapping") as reported here https://github.com/starfive-tech/linux/issues/17. Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-06-28Merge tag 'sched-core-2021-06-28' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler udpates from Ingo Molnar: - Changes to core scheduling facilities: - Add "Core Scheduling" via CONFIG_SCHED_CORE=y, which enables coordinated scheduling across SMT siblings. This is a much requested feature for cloud computing platforms, to allow the flexible utilization of SMT siblings, without exposing untrusted domains to information leaks & side channels, plus to ensure more deterministic computing performance on SMT systems used by heterogenous workloads. There are new prctls to set core scheduling groups, which allows more flexible management of workloads that can share siblings. - Fix task->state access anti-patterns that may result in missed wakeups and rename it to ->__state in the process to catch new abuses. - Load-balancing changes: - Tweak newidle_balance for fair-sched, to improve 'memcache'-like workloads. - "Age" (decay) average idle time, to better track & improve workloads such as 'tbench'. - Fix & improve energy-aware (EAS) balancing logic & metrics. - Fix & improve the uclamp metrics. - Fix task migration (taskset) corner case on !CONFIG_CPUSET. - Fix RT and deadline utilization tracking across policy changes - Introduce a "burstable" CFS controller via cgroups, which allows bursty CPU-bound workloads to borrow a bit against their future quota to improve overall latencies & batching. Can be tweaked via /sys/fs/cgroup/cpu/<X>/cpu.cfs_burst_us. - Rework assymetric topology/capacity detection & handling. - Scheduler statistics & tooling: - Disable delayacct by default, but add a sysctl to enable it at runtime if tooling needs it. Use static keys and other optimizations to make it more palatable. - Use sched_clock() in delayacct, instead of ktime_get_ns(). - Misc cleanups and fixes. * tag 'sched-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (72 commits) sched/doc: Update the CPU capacity asymmetry bits sched/topology: Rework CPU capacity asymmetry detection sched/core: Introduce SD_ASYM_CPUCAPACITY_FULL sched_domain flag psi: Fix race between psi_trigger_create/destroy sched/fair: Introduce the burstable CFS controller sched/uclamp: Fix uclamp_tg_restrict() sched/rt: Fix Deadline utilization tracking during policy change sched/rt: Fix RT utilization tracking during policy change sched: Change task_struct::state sched,arch: Remove unused TASK_STATE offsets sched,timer: Use __set_current_state() sched: Add get_current_state() sched,perf,kvm: Fix preemption condition sched: Introduce task_is_running() sched: Unbreak wakeups sched/fair: Age the average idle time sched/cpufreq: Consider reduced CPU capacity in energy calculation sched/fair: Take thermal pressure into account while estimating energy thermal/cpufreq_cooling: Update offline CPUs per-cpu thermal_pressure sched/fair: Return early from update_tg_cfs_load() if delta == 0 ...
2021-06-28Merge tag 'perf-core-2021-06-28' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf events updates from Ingo Molnar: - Platform PMU driver updates: - x86 Intel uncore driver updates for Skylake (SNR) and Icelake (ICX) servers - Fix RDPMC support - Fix [extended-]PEBS-via-PT support - Fix Sapphire Rapids event constraints - Fix :ppp support on Sapphire Rapids - Fix fixed counter sanity check on Alder Lake & X86_FEATURE_HYBRID_CPU - Other heterogenous-PMU fixes - Kprobes: - Remove the unused and misguided kprobe::fault_handler callbacks. - Warn about kprobes taking a page fault. - Fix the 'nmissed' stat counter. - Misc cleanups and fixes. * tag 'perf-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Fix task context PMU for Hetero perf/x86/intel: Fix instructions:ppp support in Sapphire Rapids perf/x86/intel: Add more events requires FRONTEND MSR on Sapphire Rapids perf/x86/intel: Fix fixed counter check warning for some Alder Lake perf/x86/intel: Fix PEBS-via-PT reload base value for Extended PEBS perf/x86: Reset the dirty counter to prevent the leak for an RDPMC task kprobes: Do not increment probe miss count in the fault handler x86,kprobes: WARN if kprobes tries to handle a fault kprobes: Remove kprobe::fault_handler uprobes: Update uprobe_write_opcode() kernel-doc comment perf/hw_breakpoint: Fix DocBook warnings in perf hw_breakpoint perf/core: Fix DocBook warnings perf/core: Make local function perf_pmu_snapshot_aux() static perf/x86/intel/uncore: Enable I/O stacks to IIO PMON mapping on ICX perf/x86/intel/uncore: Enable I/O stacks to IIO PMON mapping on SNR perf/x86/intel/uncore: Generalize I/O stacks to PMON mapping procedure perf/x86/intel/uncore: Drop unnecessary NULL checks after container_of()
2021-06-18sched: Introduce task_is_running()Peter Zijlstra
Replace a bunch of 'p->state == TASK_RUNNING' with a new helper: task_is_running(p). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Davidlohr Bueso <dave@stgolabs.net> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20210611082838.222401495@infradead.org
2021-06-18Merge branch 'sched/urgent' into sched/core, to resolve conflictsIngo Molnar
This commit in sched/urgent moved the cfs_rq_is_decayed() function: a7b359fc6a37: ("sched/fair: Correctly insert cfs_rq's to list on unthrottle") and this fresh commit in sched/core modified it in the old location: 9e077b52d86a: ("sched/pelt: Check that *_avg are null when *_sum are") Merge the two variants. Conflicts: kernel/sched/fair.c Signed-off-by: Ingo Molnar <mingo@kernel.org>
2021-06-11riscv: Only initialize swiotlb when necessaryKefeng Wang
The SWIOTLB buffer is not needed unless the physical address space is beyond the limit of dma, only initialize swiotlb when swiotlb_force is true or not all system memory is DMA-able. Also move the swiotlb_init() into mem_init(). Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-06-10riscv: xip: support runtime trap patchingVitaly Wool
RISCV_ERRATA_ALTERNATIVE patches text at runtime which is currently not possible when the kernel is executed from the flash in XIP mode. Since runtime patching concerns only traps at the moment, let's just have all the traps reside in RAM anyway if RISCV_ERRATA_ALTERNATIVE is set. Thus, these functions will be patch-able even when the .text section is in flash. Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-06-03Merge branch 'sched/urgent' into sched/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2021-06-03kprobes: Do not increment probe miss count in the fault handlerNaveen N. Rao
Kprobes has a counter 'nmissed', that is used to count the number of times a probe handler was not called. This generally happens when we hit a kprobe while handling another kprobe. However, if one of the probe handlers causes a fault, we are currently incrementing 'nmissed'. The comment in fault handler indicates that this can be used to account faults taken by the probe handlers. But, this has never been the intention as is evident from the comment above 'nmissed' in 'struct kprobe': /*count the number of times this probe was temporarily disarmed */ unsigned long nmissed; Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Link: https://lkml.kernel.org/r/20210601120150.672652-1-naveen.n.rao@linux.vnet.ibm.com
2021-06-01RISC-V: Fix memblock_free() usages in init_resources()Wende Tan
`memblock_free()` takes a physical address as its first argument. Fix the wrong usages in `init_resources()`. Fixes: ffe0e526126884cf036a6f724220f1f9b4094fd2 ("RISC-V: Improve init_resources()") Fixes: 797f0375dd2ef5cdc68ac23450cbae9a5c67a74e ("RISC-V: Do not allocate memblock while iterating reserved memblocks") Signed-off-by: Wende Tan <twd2.me@gmail.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-06-01kprobes: Remove kprobe::fault_handlerPeter Zijlstra
The reason for kprobe::fault_handler(), as given by their comment: * We come here because instructions in the pre/post * handler caused the page_fault, this could happen * if handler tries to access user space by * copy_from_user(), get_user() etc. Let the * user-specified handler try to fix it first. Is just plain bad. Those other handlers are ran from non-preemptible context and had better use _nofault() functions. Also, there is no upstream usage of this. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Link: https://lore.kernel.org/r/20210525073213.561116662@infradead.org
2021-05-29riscv: Add __init section marker to some functions againJisheng Zhang
These functions are not needed after booting, so mark them as __init to move them to the __init section. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-05-29riscv: kprobes: Remove redundant kprobe_step_ctxJisheng Zhang
Inspired by commit ba090f9cafd5 ("arm64: kprobes: Remove redundant kprobe_step_ctx"), the ss_pending and match_addr of kprobe_step_ctx are redundant because those can be replaced by KPROBE_HIT_SS and &cur_kprobe->ainsn.api.insn[0] + GET_INSN_LENGTH(cur->opcode) respectively. Remove the kprobe_step_ctx to simplify the code. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-05-25riscv: Turn has_fpu into a static key if FPU=yJisheng Zhang
The has_fpu check sits at hot code path: switch_to(). Currently, has_fpu is a bool variable if FPU=y, switch_to() checks it each time, we can optimize out this check by turning the has_fpu into a static key. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-05-25riscv: Move setup_bootmem into paging_initKefeng Wang
Make setup_bootmem() static. Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-05-22riscv: kexec: Fix W=1 build warningsJisheng Zhang
Fixes the following W=1 build warning(s): In file included from include/linux/kexec.h:28, from arch/riscv/kernel/machine_kexec.c:7: arch/riscv/include/asm/kexec.h:45:1: warning: ‘extern’ is not at beginning of declaration [-Wold-style-declaration] 45 | const extern unsigned char riscv_kexec_relocate[]; | ^~~~~ arch/riscv/include/asm/kexec.h:46:1: warning: ‘extern’ is not at beginning of declaration [-Wold-style-declaration] 46 | const extern unsigned int riscv_kexec_relocate_size; | ^~~~~ arch/riscv/kernel/machine_kexec.c:125:6: warning: no previous prototype for ‘machine_shutdown’ [-Wmissing-prototypes] 125 | void machine_shutdown(void) | ^~~~~~~~~~~~~~~~ arch/riscv/kernel/machine_kexec.c:147:1: warning: no previous prototype for ‘machine_crash_shutdown’ [-Wmissing-prototypes] 147 | machine_crash_shutdown(struct pt_regs *regs) | ^~~~~~~~~~~~~~~~~~~~~~ arch/riscv/kernel/machine_kexec.c:23: warning: Function parameter or member 'image' not described in 'kexec_image_info' arch/riscv/kernel/machine_kexec.c:53: warning: Function parameter or member 'image' not described in 'machine_kexec_prepare' arch/riscv/kernel/machine_kexec.c:114: warning: Function parameter or member 'image' not described in 'machine_kexec_cleanup' arch/riscv/kernel/machine_kexec.c:148: warning: Function parameter or member 'regs' not described in 'machine_crash_shutdown' arch/riscv/kernel/machine_kexec.c:167: warning: Function parameter or member 'image' not described in 'machine_kexec' Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-05-22riscv: kprobes: Fix build error when MMU=nJisheng Zhang
lkp reported a randconfig failure: arch/riscv/kernel/probes/kprobes.c:90:22: error: use of undeclared identifier 'PAGE_KERNEL_READ_EXEC' We implemented the alloc_insn_page() to allocate PAGE_KERNEL_READ_EXEC page for kprobes insn page for STRICT_MODULE_RWX. But if MMU=n, we should fall back to the generic weak alloc_insn_page() by generic kprobe subsystem. Fixes: cdd1b2bd358f ("riscv: kprobes: Implement alloc_insn_page()") Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-05-22riscv: stacktrace: fix the riscv stacktrace when CONFIG_FRAME_POINTER enabledChen Huang
As [1] and [2] said, the arch_stack_walk should not to trace itself, or it will leave the trace unexpectedly when called. The example is when we do "cat /sys/kernel/debug/page_owner", all pages' stack is the same. arch_stack_walk+0x18/0x20 stack_trace_save+0x40/0x60 register_dummy_stack+0x24/0x5e init_page_owner+0x2e So we use __builtin_frame_address(1) as the first frame to be walked. And mark the arch_stack_walk() noinline. We found that pr_cont will affact pages' stack whose task state is RUNNING when testing "echo t > /proc/sysrq-trigger". So move the place of pr_cont and mark the function dump_backtrace() noinline. Also we move the case when task == NULL into else branch, and test for it in "echo c > /proc/sysrq-trigger". [1] https://lore.kernel.org/lkml/20210319184106.5688-1-mark.rutland@arm.com/ [2] https://lore.kernel.org/lkml/20210317142050.57712-1-chenjun102@huawei.com/ Signed-off-by: Chen Huang <chenhuang5@huawei.com> Fixes: 5d8544e2d007 ("RISC-V: Generic library routines and assembly") Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-05-12sched/core: Initialize the idle task with preemption disabledValentin Schneider
As pointed out by commit de9b8f5dcbd9 ("sched: Fix crash trying to dequeue/enqueue the idle thread") init_idle() can and will be invoked more than once on the same idle task. At boot time, it is invoked for the boot CPU thread by sched_init(). Then smp_init() creates the threads for all the secondary CPUs and invokes init_idle() on them. As the hotplug machinery brings the secondaries to life, it will issue calls to idle_thread_get(), which itself invokes init_idle() yet again. In this case it's invoked twice more per secondary: at _cpu_up(), and at bringup_cpu(). Given smp_init() already initializes the idle tasks for all *possible* CPUs, no further initialization should be required. Now, removing init_idle() from idle_thread_get() exposes some interesting expectations with regards to the idle task's preempt_count: the secondary startup always issues a preempt_disable(), requiring some reset of the preempt count to 0 between hot-unplug and hotplug, which is currently served by idle_thread_get() -> idle_init(). Given the idle task is supposed to have preemption disabled once and never see it re-enabled, it seems that what we actually want is to initialize its preempt_count to PREEMPT_DISABLED and leave it there. Do that, and remove init_idle() from idle_thread_get(). Secondary startups were patched via coccinelle: @begone@ @@ -preempt_disable(); ... cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20210512094636.2958515-1-valentin.schneider@arm.com
2021-05-06riscv: remove unused handle_exception symbolRouven Czerwinski
Since commit 79b1feba5455 ("RISC-V: Setup exception vector early") exception vectors are setup early and the handle_exception symbol from the asm files is no longer referenced in traps.c. Remove it. Signed-off-by: Rouven Czerwinski <rouven@czerwinskis.de> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-05-06riscv: Consistify protect_kernel_linear_mapping_text_rodata() useGeert Uytterhoeven
The various uses of protect_kernel_linear_mapping_text_rodata() are not consistent: - Its definition depends on "64BIT && !XIP_KERNEL", - Its forward declaration depends on MMU, - Its single caller depends on "STRICT_KERNEL_RWX && 64BIT && MMU && !XIP_KERNEL". Fix this by settling on the dependencies of the caller, which can be simplified as STRICT_KERNEL_RWX depends on "MMU && !XIP_KERNEL". Provide a dummy definition, as the caller is protected by "IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)" instead of "#ifdef CONFIG_STRICT_KERNEL_RWX". Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Alexandre Ghiti <alex@ghiti.fr> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-05-06Merge tag 'riscv-for-linus-5.13-mw0' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V updates from Palmer Dabbelt: - Support for the memtest= kernel command-line argument. - Support for building the kernel with FORTIFY_SOURCE. - Support for generic clockevent broadcasts. - Support for the buildtar build target. - Some build system cleanups to pass more LLVM-friendly arguments. - Support for kprobes. - A rearranged kernel memory map, the first part of supporting sv48 systems. - Improvements to kexec, along with support for kdump and crash kernels. - An alternatives-based errata framework, along with support for handling a pair of errata that manifest on some SiFive designs (including the HiFive Unmatched). - Support for XIP. - A device tree for the Microchip PolarFire ICICLE SoC and associated dev board. ... along with a bunch of cleanups. There are already a handful of fixes on the list so there will likely be a part 2. * tag 'riscv-for-linus-5.13-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (45 commits) RISC-V: Always define XIP_FIXUP riscv: Remove 32b kernel mapping from page table dump riscv: Fix 32b kernel build with CONFIG_DEBUG_VIRTUAL=y RISC-V: Fix error code returned by riscv_hartid_to_cpuid() RISC-V: Enable Microchip PolarFire ICICLE SoC RISC-V: Initial DTS for Microchip ICICLE board dt-bindings: riscv: microchip: Add YAML documentation for the PolarFire SoC RISC-V: Add Microchip PolarFire SoC kconfig option RISC-V: enable XIP RISC-V: Add crash kernel support RISC-V: Add kdump support RISC-V: Improve init_resources() RISC-V: Add kexec support RISC-V: Add EM_RISCV to kexec UAPI header riscv: vdso: fix and clean-up Makefile riscv/mm: Use BUG_ON instead of if condition followed by BUG. riscv/kprobe: fix kernel panic when invoking sys_read traced by kprobe riscv: Set ARCH_HAS_STRICT_MODULE_RWX if MMU riscv: module: Create module allocations without exec permissions riscv: bpf: Avoid breaking W^X ...
2021-05-01RISC-V: Fix error code returned by riscv_hartid_to_cpuid()Anup Patel
We should return a negative error code upon failure in riscv_hartid_to_cpuid() instead of NR_CPUS. This is also aligned with all uses of riscv_hartid_to_cpuid() which expect negative error code upon failure. Fixes: 6825c7a80f18 ("RISC-V: Add logical CPU indexing for RISC-V") Fixes: f99fb607fb2b ("RISC-V: Use Linux logical CPU number instead of hartid") Signed-off-by: Anup Patel <anup.patel@wdc.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26RISC-V: enable XIPVitaly Wool
Introduce XIP (eXecute In Place) support for RISC-V platforms. It allows code to be executed directly from non-volatile storage directly addressable by the CPU, such as QSPI NOR flash which can be found on many RISC-V platforms. This makes way for significant optimization of RAM footprint. The XIP kernel is not compressed since it has to run directly from flash, so it will occupy more space on the non-volatile storage. The physical flash address used to link the kernel object files and for storing it has to be known at compile time and is represented by a Kconfig option. XIP on RISC-V will for the time being only work on MMU-enabled kernels. Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.com> [Alex: Rebase on top of "Move kernel mapping outside the linear mapping" ] Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> [Palmer: disable XIP for allyesconfig] Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26RISC-V: Add crash kernel supportNick Kossifidis
This patch allows Linux to act as a crash kernel for use with kdump. Userspace will let the crash kernel know about the memory region it can use through linux,usable-memory property on the /memory node (overriding its reg property), and about the memory region where the elf core header of the previous kernel is saved, through a reserved-memory node with a compatible string of "linux,elfcorehdr". This approach is the least invasive and re-uses functionality already present. I tested this on riscv64 qemu and it works as expected, you may test it by retrieving the dmesg of the previous kernel through /proc/vmcore, using the vmcore-dmesg utility from kexec-tools. Signed-off-by: Nick Kossifidis <mick@ics.forth.gr> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26RISC-V: Add kdump supportNick Kossifidis
This patch adds support for kdump, the kernel will reserve a region for the crash kernel and jump there on panic. In order for userspace tools (kexec-tools) to prepare the crash kernel kexec image, we also need to expose some information on /proc/iomem for the memory regions used by the kernel and for the region reserved for crash kernel. Note that on userspace the device tree is used to determine the system's memory layout so the "System RAM" on /proc/iomem is ignored. I tested this on riscv64 qemu and works as expected, you may test it by triggering a crash through /proc/sysrq_trigger: echo c > /proc/sysrq_trigger Signed-off-by: Nick Kossifidis <mick@ics.forth.gr> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26RISC-V: Improve init_resources()Nick Kossifidis
The kernel region is always present and we know where it is, no need to look for it inside the loop, just ignore it like the rest of the reserved regions within system's memory. Additionally, we don't need to call memblock_free inside the loop, as if called it'll split the region of pre-allocated resources in two parts, messing things up, just re-use the previous pre-allocated resource and free any unused resources after both loops finish. Signed-off-by: Nick Kossifidis <mick@ics.forth.gr> [Palmer: commit text] Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26RISC-V: Add kexec supportNick Kossifidis
This patch adds support for kexec on RISC-V. On SMP systems it depends on HOTPLUG_CPU in order to be able to bring up all harts after kexec. It also needs a recent OpenSBI version that supports the HSM extension. I tested it on riscv64 QEMU on both an smp and a non-smp system. Signed-off-by: Nick Kossifidis <mick@ics.forth.gr> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26riscv: vdso: fix and clean-up MakefileJisheng Zhang
Running "make" on an already compiled kernel tree will rebuild the kernel even without any modifications: CALL linux/scripts/checksyscalls.sh CALL linux/scripts/atomic/check-atomics.sh CHK include/generated/compile.h SO2S arch/riscv/kernel/vdso/vdso-syms.S AS arch/riscv/kernel/vdso/vdso-syms.o AR arch/riscv/kernel/vdso/built-in.a AR arch/riscv/kernel/built-in.a AR arch/riscv/built-in.a GEN .version CHK include/generated/compile.h UPD include/generated/compile.h CC init/version.o AR init/built-in.a LD vmlinux.o The reason is "Any target that utilizes if_changed must be listed in $(targets), otherwise the command line check will fail, and the target will always be built" as explained by Documentation/kbuild/makefiles.rst Fix this build bug by adding vdso-syms.S to $(targets) At the same time, there are two trivial clean up modifications: - the vdso-dummy.o is not needed any more after so remove it. - vdso.lds is a generated file, so it should be prefixed with $(obj)/ instead of $(src)/ Fixes: c2c81bb2f691 ("RISC-V: Fix the VDSO symbol generaton for binutils-2.35+") Cc: stable@vger.kernel.org Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26riscv/kprobe: fix kernel panic when invoking sys_read traced by kprobeLiao Chang
The execution of sys_read end up hitting a BUG_ON() in __find_get_block after installing kprobe at sys_read, the BUG message like the following: [ 65.708663] ------------[ cut here ]------------ [ 65.709987] kernel BUG at fs/buffer.c:1251! [ 65.711283] Kernel BUG [#1] [ 65.712032] Modules linked in: [ 65.712925] CPU: 0 PID: 51 Comm: sh Not tainted 5.12.0-rc4 #1 [ 65.714407] Hardware name: riscv-virtio,qemu (DT) [ 65.715696] epc : __find_get_block+0x218/0x2c8 [ 65.716835] ra : __getblk_gfp+0x1c/0x4a [ 65.717831] epc : ffffffe00019f11e ra : ffffffe00019f56a sp : ffffffe002437930 [ 65.719553] gp : ffffffe000f06030 tp : ffffffe0015abc00 t0 : ffffffe00191e038 [ 65.721290] t1 : ffffffe00191e038 t2 : 000000000000000a s0 : ffffffe002437960 [ 65.723051] s1 : ffffffe00160ad00 a0 : ffffffe00160ad00 a1 : 000000000000012a [ 65.724772] a2 : 0000000000000400 a3 : 0000000000000008 a4 : 0000000000000040 [ 65.726545] a5 : 0000000000000000 a6 : ffffffe00191e000 a7 : 0000000000000000 [ 65.728308] s2 : 000000000000012a s3 : 0000000000000400 s4 : 0000000000000008 [ 65.730049] s5 : 000000000000006c s6 : ffffffe00240f800 s7 : ffffffe000f080a8 [ 65.731802] s8 : 0000000000000001 s9 : 000000000000012a s10: 0000000000000008 [ 65.733516] s11: 0000000000000008 t3 : 00000000000003ff t4 : 000000000000000f [ 65.734434] t5 : 00000000000003ff t6 : 0000000000040000 [ 65.734613] status: 0000000000000100 badaddr: 0000000000000000 cause: 0000000000000003 [ 65.734901] Call Trace: [ 65.735076] [<ffffffe00019f11e>] __find_get_block+0x218/0x2c8 [ 65.735417] [<ffffffe00020017a>] __ext4_get_inode_loc+0xb2/0x2f6 [ 65.735618] [<ffffffe000201b6c>] ext4_get_inode_loc+0x3a/0x8a [ 65.735802] [<ffffffe000203380>] ext4_reserve_inode_write+0x2e/0x8c [ 65.735999] [<ffffffe00020357a>] __ext4_mark_inode_dirty+0x4c/0x18e [ 65.736208] [<ffffffe000206bb0>] ext4_dirty_inode+0x46/0x66 [ 65.736387] [<ffffffe000192914>] __mark_inode_dirty+0x12c/0x3da [ 65.736576] [<ffffffe000180dd2>] touch_atime+0x146/0x150 [ 65.736748] [<ffffffe00010d762>] filemap_read+0x234/0x246 [ 65.736920] [<ffffffe00010d834>] generic_file_read_iter+0xc0/0x114 [ 65.737114] [<ffffffe0001f5d7a>] ext4_file_read_iter+0x42/0xea [ 65.737310] [<ffffffe000163f2c>] new_sync_read+0xe2/0x15a [ 65.737483] [<ffffffe000165814>] vfs_read+0xca/0xf2 [ 65.737641] [<ffffffe000165bae>] ksys_read+0x5e/0xc8 [ 65.737816] [<ffffffe000165c26>] sys_read+0xe/0x16 [ 65.737973] [<ffffffe000003972>] ret_from_syscall+0x0/0x2 [ 65.738858] ---[ end trace fe93f985456c935d ]--- A simple reproducer looks like: echo 'p:myprobe sys_read fd=%a0 buf=%a1 count=%a2' > /sys/kernel/debug/tracing/kprobe_events echo 1 > /sys/kernel/debug/tracing/events/kprobes/myprobe/enable cat /sys/kernel/debug/tracing/trace Here's what happens to hit that BUG_ON(): 1) After installing kprobe at entry of sys_read, the first instruction is replaced by 'ebreak' instruction on riscv64 platform. 2) Once kernel reach the 'ebreak' instruction at the entry of sys_read, it trap into the riscv breakpoint handler, where it do something to setup for coming single-step of origin instruction, including backup the 'sstatus' in pt_regs, followed by disable interrupt during single stepping via clear 'SIE' bit of 'sstatus' in pt_regs. 3) Then kernel restore to the instruction slot contains two instructions, one is original instruction at entry of sys_read, the other is 'ebreak'. Here it trigger a 'Instruction page fault' exception (value at 'scause' is '0xc'), if PF is not filled into PageTabe for that slot yet. 4) Again kernel trap into page fault exception handler, where it choose different policy according to the state of running kprobe. Because afte 2) the state is KPROBE_HIT_SS, so kernel reset the current kprobe and 'pc' points back to the probe address. 5) Because 'epc' point back to 'ebreak' instrution at sys_read probe, kernel trap into breakpoint handler again, and repeat the operations at 2), however 'sstatus' without 'SIE' is keep at 4), it cause the real 'sstatus' saved at 2) is overwritten by the one withou 'SIE'. 6) When kernel cross the probe the 'sstatus' CSR restore with value without 'SIE', and reach __find_get_block where it requires the interrupt must be enabled. Fix this is very trivial, just restore the value of 'sstatus' in pt_regs with backup one at 2) when the instruction being single stepped cause a page fault. Fixes: c22b0bcb1dd02 ("riscv: Add kprobes supported") Signed-off-by: Liao Chang <liaochang1@huawei.com> Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26riscv: module: Create module allocations without exec permissionsJisheng Zhang
The core code manages the executable permissions of code regions of modules explicitly, it is not necessary to create the module vmalloc regions with RWX permissions. Create them with RW- permissions instead. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26riscv: kprobes: Implement alloc_insn_page()Jisheng Zhang
Allocate PAGE_KERNEL_READ_EXEC(read only, executable) page for kprobes insn page. This is to prepare for STRICT_MODULE_RWX. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26riscv: Constify sbi_ipi_opsJisheng Zhang
Constify the sbi_ipi_ops so that it will be placed in the .rodata section. This will cause attempts to modify it to fail when strict page permissions are in place. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26riscv: Constify sys_call_tableJisheng Zhang
Constify the sys_call_table so that it will be placed in the .rodata section. This will cause attempts to modify the table to fail when strict page permissions are in place. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26riscv: Mark some global variables __ro_after_initJisheng Zhang
All of these are never modified after init, so they can be __ro_after_init. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26riscv: add __init section marker to some functionsJisheng Zhang
They are not needed after booting, so mark them as __init to move them to the __init section. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26riscv: Move kernel mapping outside of linear mappingAlexandre Ghiti
This is a preparatory patch for relocatable kernel and sv48 support. The kernel used to be linked at PAGE_OFFSET address therefore we could use the linear mapping for the kernel mapping. But the relocated kernel base address will be different from PAGE_OFFSET and since in the linear mapping, two different virtual addresses cannot point to the same physical address, the kernel mapping needs to lie outside the linear mapping so that we don't have to copy it at the same physical offset. The kernel mapping is moved to the last 2GB of the address space, BPF is now always after the kernel and modules use the 2GB memory range right before the kernel, so BPF and modules regions do not overlap. KASLR implementation will simply have to move the kernel in the last 2GB range and just take care of leaving enough space for BPF. In addition, by moving the kernel to the end of the address space, both sv39 and sv48 kernels will be exactly the same without needing to be relocated at runtime. Suggested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> [Palmer: Squash the STRICT_RWX fix, and a !MMU fix] Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26riscv: Workaround mcount name prior to clang-13Nathan Chancellor
Prior to clang 13.0.0, the RISC-V name for the mcount symbol was "mcount", which differs from the GCC version of "_mcount", which results in the following errors: riscv64-linux-gnu-ld: init/main.o: in function `__traceiter_initcall_level': main.c:(.text+0xe): undefined reference to `mcount' riscv64-linux-gnu-ld: init/main.o: in function `__traceiter_initcall_start': main.c:(.text+0x4e): undefined reference to `mcount' riscv64-linux-gnu-ld: init/main.o: in function `__traceiter_initcall_finish': main.c:(.text+0x92): undefined reference to `mcount' riscv64-linux-gnu-ld: init/main.o: in function `.LBB32_28': main.c:(.text+0x30c): undefined reference to `mcount' riscv64-linux-gnu-ld: init/main.o: in function `free_initmem': main.c:(.text+0x54c): undefined reference to `mcount' This has been corrected in https://reviews.llvm.org/D98881 but the minimum supported clang version is 10.0.1. To avoid build errors and to gain a working function tracer, adjust the name of the mcount symbol for older versions of clang in mount.S and recordmcount.pl. Link: https://github.com/ClangBuiltLinux/linux/issues/1331 Signed-off-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26riscv: Use $(LD) instead of $(CC) to link vDSONathan Chancellor
Currently, the VDSO is being linked through $(CC). This does not match how the rest of the kernel links objects, which is through the $(LD) variable. When linking with clang, there are a couple of warnings about flags that will not be used during the link: clang-12: warning: argument unused during compilation: '-no-pie' [-Wunused-command-line-argument] clang-12: warning: argument unused during compilation: '-pg' [-Wunused-command-line-argument] '-no-pie' was added in commit 85602bea297f ("RISC-V: build vdso-dummy.o with -no-pie") to override '-pie' getting added to the ld command from distribution versions of GCC that enable PIE by default. It is technically no longer needed after commit c2c81bb2f691 ("RISC-V: Fix the VDSO symbol generaton for binutils-2.35+"), which removed vdso-dummy.o in favor of generating vdso-syms.S from vdso.so with $(NM) but this also resolves the issue in case it ever comes back due to having full control over the $(LD) command. '-pg' is for function tracing, it is not used during linking as clang states. These flags could be removed/filtered to fix the warnings but it is easier to just match the rest of the kernel and use $(LD) directly for linking. See commits fe00e50b2db8 ("ARM: 8858/1: vdso: use $(LD) instead of $(CC) to link VDSO") 691efbedc60d ("arm64: vdso: use $(LD) instead of $(CC) to link VDSO") 2ff906994b6c ("MIPS: VDSO: Use $(LD) instead of $(CC) to link VDSO") 2b2a25845d53 ("s390/vdso: Use $(LD) instead of $(CC) to link vDSO") for more information. The flags are converted to linker flags and '--eh-frame-hdr' is added to match what is added by GCC implicitly, which can be seen by adding '-v' to GCC's invocation. Additionally, since this area is being modified, use the $(OBJCOPY) variable instead of an open coded $(CROSS_COMPILE)objcopy so that the user's choice of objcopy binary is respected. Link: https://github.com/ClangBuiltLinux/linux/issues/803 Link: https://github.com/ClangBuiltLinux/linux/issues/970 Signed-off-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Fangrui Song <maskray@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-17 14:13:49 +0000