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path: root/arch/riscv/kernel/traps.c
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2025-01-08riscv: Fix sleeping in invalid context in die()Nam Cao
die() can be called in exception handler, and therefore cannot sleep. However, die() takes spinlock_t which can sleep with PREEMPT_RT enabled. That causes the following warning: BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 285, name: mutex preempt_count: 110001, expected: 0 RCU nest depth: 0, expected: 0 CPU: 0 UID: 0 PID: 285 Comm: mutex Not tainted 6.12.0-rc7-00022-ge19049cf7d56-dirty #234 Hardware name: riscv-virtio,qemu (DT) Call Trace: dump_backtrace+0x1c/0x24 show_stack+0x2c/0x38 dump_stack_lvl+0x5a/0x72 dump_stack+0x14/0x1c __might_resched+0x130/0x13a rt_spin_lock+0x2a/0x5c die+0x24/0x112 do_trap_insn_illegal+0xa0/0xea _new_vmalloc_restore_context_a0+0xcc/0xd8 Oops - illegal instruction [#1] Switch to use raw_spinlock_t, which does not sleep even with PREEMPT_RT enabled. Fixes: 76d2a0493a17 ("RISC-V: Init and Halt Code") Signed-off-by: Nam Cao <namcao@linutronix.de> Cc: stable@vger.kernel.org Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: https://lore.kernel.org/r/20241118091333.1185288-1-namcao@linutronix.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-08-14riscv: entry: always initialize regs->a0 to -ENOSYSCeleste Liu
Otherwise when the tracer changes syscall number to -1, the kernel fails to initialize a0 with -ENOSYS and subsequently fails to return the error code of the failed syscall to userspace. For example, it will break strace syscall tampering. Fixes: 52449c17bdd1 ("riscv: entry: set a0 = -ENOSYS only when syscall != -1") Reported-by: "Dmitry V. Levin" <ldv@strace.io> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Cc: stable@vger.kernel.org Signed-off-by: Celeste Liu <CoelacanthusHex@gmail.com> Link: https://lore.kernel.org/r/20240627142338.5114-2-CoelacanthusHex@gmail.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-04-04riscv: use KERN_INFO in do_trapAndreas Schwab
Print the instruction dump with info instead of emergency level. The unhandled signal message is only for informational purpose. Fixes: b8a03a634129 ("riscv: add userland instruction dump to RISC-V splats") Signed-off-by: Andreas Schwab <schwab@suse.de> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Reviewed-by: Yunhui Cui <cuiyunhui@bytedance.com> Link: https://lore.kernel.org/r/mvmy1aegrhm.fsf@suse.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-24riscv: Support RANDOMIZE_KSTACK_OFFSETSong Shuai
Inspired from arm64's implement -- commit 70918779aec9 ("arm64: entry: Enable random_kstack_offset support") Add support of kernel stack offset randomization while handling syscall, the offset is defaultly limited by KSTACK_OFFSET_MAX() (i.e. 10 bits). In order to avoid trigger stack canaries (due to __builtin_alloca) and slowing down the entry path, use __no_stack_protector attribute to disable stack protector for do_trap_ecall_u() at the function level. Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Song Shuai <songshuaishuai@tinylab.org> Link: https://lore.kernel.org/r/20231109133751.212079-1-songshuaishuai@tinylab.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-11-09Merge patch "drivers: perf: Do not broadcast to other cpus when starting a ↵Palmer Dabbelt
counter" This is really just a single patch, but since the offending fix hasn't yet made it to my for-next I'm merging it here. Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-11-05riscv: add userland instruction dump to RISC-V splatsYunhui Cui
Add userland instruction dump and rename dump_kernel_instr() to dump_instr(). An example: [ 0.822439] Freeing unused kernel image (initmem) memory: 6916K [ 0.823817] Run /init as init process [ 0.839411] init[1]: unhandled signal 4 code 0x1 at 0x000000000005be18 in bb[10000+5fb000] [ 0.840751] CPU: 0 PID: 1 Comm: init Not tainted 5.14.0-rc4-00049-gbd644290aa72-dirty #187 [ 0.841373] Hardware name: , BIOS [ 0.841743] epc : 000000000005be18 ra : 0000000000079e74 sp : 0000003fffcafda0 [ 0.842271] gp : ffffffff816e9dc8 tp : 0000000000000000 t0 : 0000000000000000 [ 0.842947] t1 : 0000003fffc9fdf0 t2 : 0000000000000000 s0 : 0000000000000000 [ 0.843434] s1 : 0000000000000000 a0 : 0000003fffca0190 a1 : 0000003fffcafe18 [ 0.843891] a2 : 0000000000000000 a3 : 0000000000000000 a4 : 0000000000000000 [ 0.844357] a5 : 0000000000000000 a6 : 0000000000000000 a7 : 0000000000000000 [ 0.844803] s2 : 0000000000000000 s3 : 0000000000000000 s4 : 0000000000000000 [ 0.845253] s5 : 0000000000000000 s6 : 0000000000000000 s7 : 0000000000000000 [ 0.845722] s8 : 0000000000000000 s9 : 0000000000000000 s10: 0000000000000000 [ 0.846180] s11: 0000000000d144e0 t3 : 0000000000000000 t4 : 0000000000000000 [ 0.846616] t5 : 0000000000000000 t6 : 0000000000000000 [ 0.847204] status: 0000000200000020 badaddr: 00000000f0028053 cause: 0000000000000002 [ 0.848219] Code: f06f ff5f 3823 fa11 0113 fb01 2e23 0201 0293 0000 (8053) f002 [ 0.851016] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004 Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20230912021349.28302-1-cuiyunhui@bytedance.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-11-05Merge patch series "Add support to handle misaligned accesses in S-mode"Palmer Dabbelt
Clément Léger <cleger@rivosinc.com> says: Since commit 61cadb9 ("Provide new description of misaligned load/store behavior compatible with privileged architecture.") in the RISC-V ISA manual, it is stated that misaligned load/store might not be supported. However, the RISC-V kernel uABI describes that misaligned accesses are supported. In order to support that, this series adds support for S-mode handling of misaligned accesses as well support for prctl(PR_UNALIGN). Handling misaligned access in kernel allows for a finer grain control of the misaligned accesses behavior, and thanks to the prctl() call, can allow disabling misaligned access emulation to generate SIGBUS. User space can then optimize its software by removing such access based on SIGBUS generation. This series is useful when using a SBI implementation that does not handle misaligned traps as well as detecting misaligned accesses generated by userspace application using the prctrl(PR_SET_UNALIGN) feature. This series can be tested using the spike simulator[1] and a modified openSBI version[2] which allows to always delegate misaligned load/store to S-mode. A test[3] that exercise various instructions/registers can be executed to verify the unaligned access support. [1] https://github.com/riscv-software-src/riscv-isa-sim [2] https://github.com/rivosinc/opensbi/tree/dev/cleger/no_misaligned [3] https://github.com/clementleger/unaligned_test * b4-shazam-merge: riscv: add support for PR_SET_UNALIGN and PR_GET_UNALIGN riscv: report misaligned accesses emulation to hwprobe riscv: annotate check_unaligned_access_boot_cpu() with __init riscv: add support for sysctl unaligned_enabled control riscv: add floating point insn support to misaligned access emulation riscv: report perf event for misaligned fault riscv: add support for misaligned trap handling in S-mode riscv: remove unused functions in traps_misaligned.c Link: https://lore.kernel.org/r/20231004151405.521596-1-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-11-01riscv: add support for misaligned trap handling in S-modeClément Léger
Misalignment trap handling is only supported for M-mode and uses direct accesses to user memory. In S-mode, when handling usermode fault, this requires to use the get_user()/put_user() accessors. Implement load_u8(), store_u8() and get_insn() using these accessors for userspace and direct text access for kernel. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20231004151405.521596-3-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-10-27riscv: Deduplicate IRQ stack switchingSami Tolvanen
With CONFIG_IRQ_STACKS, we switch to a separate per-CPU IRQ stack before calling handle_riscv_irq or __do_softirq. We currently have duplicate inline assembly snippets for stack switching in both code paths. Now that we can access per-CPU variables in assembly, implement call_on_irq_stack in assembly, and use that instead of redundant inline assembly. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Tested-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20230927224757.1154247-10-samitolvanen@google.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-10-27riscv: VMAP_STACK overflow detection thread-safeDeepak Gupta
commit 31da94c25aea ("riscv: add VMAP_STACK overflow detection") added support for CONFIG_VMAP_STACK. If overflow is detected, CPU switches to `shadow_stack` temporarily before switching finally to per-cpu `overflow_stack`. If two CPUs/harts are racing and end up in over flowing kernel stack, one or both will end up corrupting each other state because `shadow_stack` is not per-cpu. This patch optimizes per-cpu overflow stack switch by directly picking per-cpu `overflow_stack` and gets rid of `shadow_stack`. Following are the changes in this patch - Defines an asm macro to obtain per-cpu symbols in destination register. - In entry.S, when overflow is detected, per-cpu overflow stack is located using per-cpu asm macro. Computing per-cpu symbol requires a temporary register. x31 is saved away into CSR_SCRATCH (CSR_SCRATCH is anyways zero since we're in kernel). Please see Links for additional relevant disccussion and alternative solution. Tested by `echo EXHAUST_STACK > /sys/kernel/debug/provoke-crash/DIRECT` Kernel crash log below Insufficient stack space to handle exception!/debug/provoke-crash/DIRECT Task stack: [0xff20000010a98000..0xff20000010a9c000] Overflow stack: [0xff600001f7d98370..0xff600001f7d99370] CPU: 1 PID: 205 Comm: bash Not tainted 6.1.0-rc2-00001-g328a1f96f7b9 #34 Hardware name: riscv-virtio,qemu (DT) epc : __memset+0x60/0xfc ra : recursive_loop+0x48/0xc6 [lkdtm] epc : ffffffff808de0e4 ra : ffffffff0163a752 sp : ff20000010a97e80 gp : ffffffff815c0330 tp : ff600000820ea280 t0 : ff20000010a97e88 t1 : 000000000000002e t2 : 3233206874706564 s0 : ff20000010a982b0 s1 : 0000000000000012 a0 : ff20000010a97e88 a1 : 0000000000000000 a2 : 0000000000000400 a3 : ff20000010a98288 a4 : 0000000000000000 a5 : 0000000000000000 a6 : fffffffffffe43f0 a7 : 00007fffffffffff s2 : ff20000010a97e88 s3 : ffffffff01644680 s4 : ff20000010a9be90 s5 : ff600000842ba6c0 s6 : 00aaaaaac29e42b0 s7 : 00fffffff0aa3684 s8 : 00aaaaaac2978040 s9 : 0000000000000065 s10: 00ffffff8a7cad10 s11: 00ffffff8a76a4e0 t3 : ffffffff815dbaf4 t4 : ffffffff815dbaf4 t5 : ffffffff815dbab8 t6 : ff20000010a9bb48 status: 0000000200000120 badaddr: ff20000010a97e88 cause: 000000000000000f Kernel panic - not syncing: Kernel stack overflow CPU: 1 PID: 205 Comm: bash Not tainted 6.1.0-rc2-00001-g328a1f96f7b9 #34 Hardware name: riscv-virtio,qemu (DT) Call Trace: [<ffffffff80006754>] dump_backtrace+0x30/0x38 [<ffffffff808de798>] show_stack+0x40/0x4c [<ffffffff808ea2a8>] dump_stack_lvl+0x44/0x5c [<ffffffff808ea2d8>] dump_stack+0x18/0x20 [<ffffffff808dec06>] panic+0x126/0x2fe [<ffffffff800065ea>] walk_stackframe+0x0/0xf0 [<ffffffff0163a752>] recursive_loop+0x48/0xc6 [lkdtm] SMP: stopping secondary CPUs ---[ end Kernel panic - not syncing: Kernel stack overflow ]--- Cc: Guo Ren <guoren@kernel.org> Cc: Jisheng Zhang <jszhang@kernel.org> Link: https://lore.kernel.org/linux-riscv/Y347B0x4VUNOd6V7@xhacker/T/#t Link: https://lore.kernel.org/lkml/20221124094845.1907443-1-debug@rivosinc.com/ Signed-off-by: Deepak Gupta <debug@rivosinc.com> Co-developed-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Acked-by: Guo Ren <guoren@kernel.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20230927224757.1154247-9-samitolvanen@google.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-09-20riscv: Only consider swbp/ss handlers for correct privileged modeBjörn Töpel
RISC-V software breakpoint trap handlers are used for {k,u}probes. When trapping from kernelmode, only the kernelmode handlers should be considered. Vice versa, only usermode handlers for usermode traps. This is not the case on RISC-V, which can trigger a bug if a userspace process uses uprobes, and a WARN() is triggered from kernelmode (which is implemented via {c.,}ebreak). The kernel will trap on the kernelmode {c.,}ebreak, look for uprobes handlers, realize incorrectly that uprobes need to be handled, and exit the trap handler early. The trap returns to re-executing the {c.,}ebreak, and enter an infinite trap-loop. The issue was found running the BPF selftest [1]. Fix this issue by only considering the swbp/ss handlers for kernel/usermode respectively. Also, move CONFIG ifdeffery from traps.c to the asm/{k,u}probes.h headers. Note that linux/uprobes.h only include asm/uprobes.h if CONFIG_UPROBES is defined, which is why asm/uprobes.h needs to be unconditionally included in traps.c Link: https://lore.kernel.org/linux-riscv/87v8d19aun.fsf@all.your.base.are.belong.to.us/ # [1] Fixes: 74784081aac8 ("riscv: Add uprobes supported") Reviewed-by: Guo Ren <guoren@kernel.org> Reviewed-by: Nam Cao <namcaov@gmail.com> Tested-by: Puranjay Mohan <puranjay12@gmail.com> Signed-off-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20230912065619.62020-1-bjorn@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-09-01Merge tag 'riscv-for-linus-6.6-mw1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V updates from Palmer Dabbelt: - Support for the new "riscv,isa-extensions" and "riscv,isa-base" device tree interfaces for probing extensions - Support for userspace access to the performance counters - Support for more instructions in kprobes - Crash kernels can be allocated above 4GiB - Support for KCFI - Support for ELFs in !MMU configurations - ARCH_KMALLOC_MINALIGN has been reduced to 8 - mmap() defaults to sv48-sized addresses, with longer addresses hidden behind a hint (similar to Arm and Intel) - Also various fixes and cleanups * tag 'riscv-for-linus-6.6-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (51 commits) lib/Kconfig.debug: Restrict DEBUG_INFO_SPLIT for RISC-V riscv: support PREEMPT_DYNAMIC with static keys riscv: Move create_tmp_mapping() to init sections riscv: Mark KASAN tmp* page tables variables as static riscv: mm: use bitmap_zero() API riscv: enable DEBUG_FORCE_FUNCTION_ALIGN_64B riscv: remove redundant mv instructions RISC-V: mm: Document mmap changes RISC-V: mm: Update pgtable comment documentation RISC-V: mm: Add tests for RISC-V mm RISC-V: mm: Restrict address space for sv39,sv48,sv57 riscv: enable DMA_BOUNCE_UNALIGNED_KMALLOC for !dma_coherent riscv: allow kmalloc() caches aligned to the smallest value riscv: support the elf-fdpic binfmt loader binfmt_elf_fdpic: support 64-bit systems riscv: Allow CONFIG_CFI_CLANG to be selected riscv/purgatory: Disable CFI riscv: Add CFI error handling riscv: Add ftrace_stub_graph riscv: Add types to indirectly called assembly functions ...
2023-08-23riscv: Add CFI error handlingSami Tolvanen
With CONFIG_CFI_CLANG, the compiler injects a type preamble immediately before each function and a check to validate the target function type before indirect calls: ; type preamble .word <id> function: ... ; indirect call check lw t1, -4(a0) lui t2, <hi20> addiw t2, t2, <lo12> beq t1, t2, .Ltmp0 ebreak .Ltmp0: jarl a0 Implement error handling code for the ebreak traps emitted for the checks. This produces the following oops on a CFI failure (generated using lkdtm): [ 21.177245] CFI failure at lkdtm_indirect_call+0x22/0x32 [lkdtm] (target: lkdtm_increment_int+0x0/0x18 [lkdtm]; expected type: 0x3ad55aca) [ 21.178483] Kernel BUG [#1] [ 21.178671] Modules linked in: lkdtm [ 21.179037] CPU: 1 PID: 104 Comm: sh Not tainted 6.3.0-rc6-00037-g37d5ec6297ab #1 [ 21.179511] Hardware name: riscv-virtio,qemu (DT) [ 21.179818] epc : lkdtm_indirect_call+0x22/0x32 [lkdtm] [ 21.180106] ra : lkdtm_CFI_FORWARD_PROTO+0x48/0x7c [lkdtm] [ 21.180426] epc : ffffffff01387092 ra : ffffffff01386f14 sp : ff20000000453cf0 [ 21.180792] gp : ffffffff81308c38 tp : ff6000000243f080 t0 : ff20000000453b78 [ 21.181157] t1 : 000000003ad55aca t2 : 000000007e0c52a5 s0 : ff20000000453d00 [ 21.181506] s1 : 0000000000000001 a0 : ffffffff0138d170 a1 : ffffffff013870bc [ 21.181819] a2 : b5fea48dd89aa700 a3 : 0000000000000001 a4 : 0000000000000fff [ 21.182169] a5 : 0000000000000004 a6 : 00000000000000b7 a7 : 0000000000000000 [ 21.182591] s2 : ff20000000453e78 s3 : ffffffffffffffea s4 : 0000000000000012 [ 21.183001] s5 : ff600000023c7000 s6 : 0000000000000006 s7 : ffffffff013882a0 [ 21.183653] s8 : 0000000000000008 s9 : 0000000000000002 s10: ffffffff0138d878 [ 21.184245] s11: ffffffff0138d878 t3 : 0000000000000003 t4 : 0000000000000000 [ 21.184591] t5 : ffffffff8133df08 t6 : ffffffff8133df07 [ 21.184858] status: 0000000000000120 badaddr: 0000000000000000 cause: 0000000000000003 [ 21.185415] [<ffffffff01387092>] lkdtm_indirect_call+0x22/0x32 [lkdtm] [ 21.185772] [<ffffffff01386f14>] lkdtm_CFI_FORWARD_PROTO+0x48/0x7c [lkdtm] [ 21.186093] [<ffffffff01383552>] lkdtm_do_action+0x22/0x34 [lkdtm] [ 21.186445] [<ffffffff0138350c>] direct_entry+0x128/0x13a [lkdtm] [ 21.186817] [<ffffffff8033ed8c>] full_proxy_write+0x58/0xb2 [ 21.187352] [<ffffffff801d4fe8>] vfs_write+0x14c/0x33a [ 21.187644] [<ffffffff801d5328>] ksys_write+0x64/0xd4 [ 21.187832] [<ffffffff801d53a6>] sys_write+0xe/0x1a [ 21.188171] [<ffffffff80003996>] ret_from_syscall+0x0/0x2 [ 21.188595] Code: 0513 0f65 a303 ffc5 53b7 7e0c 839b 2a53 0363 0073 (9002) 9582 [ 21.189178] ---[ end trace 0000000000000000 ]--- [ 21.189590] Kernel panic - not syncing: Fatal exception Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> # ISA bits Tested-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Link: https://lore.kernel.org/r/20230710183544.999540-12-samitolvanen@google.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-08-16riscv: stack: Fixup independent irq stack for CONFIG_FRAME_POINTER=nGuo Ren
The independent irq stack uses s0 to save & restore sp, but s0 would be corrupted when CONFIG_FRAME_POINTER=n. So add s0 in the clobber list to fix the problem. Fixes: 163e76cc6ef4 ("riscv: stack: Support HAVE_IRQ_EXIT_ON_IRQ_STACK") Cc: stable@vger.kernel.org Reported-by: Zhangjin Wu <falcon@tinylab.org> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@kernel.org> Tested-by: Drew Fustini <dfustini@baylibre.com> Link: https://lore.kernel.org/r/20230716001506.3506041-2-guoren@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-08-16riscv: entry: set a0 = -ENOSYS only when syscall != -1Celeste Liu
When we test seccomp with 6.4 kernel, we found errno has wrong value. If we deny NETLINK_AUDIT with EAFNOSUPPORT, after f0bddf50586d, we will get ENOSYS instead. We got same result with commit 9c2598d43510 ("riscv: entry: Save a0 prior syscall_enter_from_user_mode()"). After analysing code, we think that regs->a0 = -ENOSYS should only be executed when syscall != -1. In __seccomp_filter, when seccomp rejected this syscall with specified errno, they will set a0 to return number as syscall ABI, and then return -1. This return number is finally pass as return number of syscall_enter_from_user_mode, and then is compared with NR_syscalls after converted to ulong (so it will be ULONG_MAX). The condition syscall < NR_syscalls will always be false, so regs->a0 = -ENOSYS is always executed. It covered a0 set by seccomp, so we always get ENOSYS when match seccomp RET_ERRNO rule. Fixes: f0bddf50586d ("riscv: entry: Convert to generic entry") Reported-by: Felix Yan <felixonmars@archlinux.org> Co-developed-by: Ruizhe Pan <c141028@gmail.com> Signed-off-by: Ruizhe Pan <c141028@gmail.com> Co-developed-by: Shiqi Zhang <shiqi@isrc.iscas.ac.cn> Signed-off-by: Shiqi Zhang <shiqi@isrc.iscas.ac.cn> Signed-off-by: Celeste Liu <CoelacanthusHex@gmail.com> Tested-by: Felix Yan <felixonmars@archlinux.org> Tested-by: Emil Renner Berthing <emil.renner.berthing@canonical.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20230801141607.435192-1-CoelacanthusHex@gmail.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-04riscv: Discard vector state on syscallsBjörn Töpel
The RISC-V vector specification states: Executing a system call causes all caller-saved vector registers (v0-v31, vl, vtype) and vstart to become unspecified. The vector registers are set to all 1s, vill is set (invalid), and the vector status is set to Dirty. That way we can prevent userspace from accidentally relying on the stated save. Rémi pointed out [1] that writing to the registers might be superfluous, and setting vill is sufficient. Link: https://lore.kernel.org/linux-riscv/12784326.9UPPK3MAeB@basile.remlab.net/ # [1] Suggested-by: Darius Rad <darius@bluespec.com> Suggested-by: Palmer Dabbelt <palmer@rivosinc.com> Suggested-by: Rémi Denis-Courmont <remi@remlab.net> Signed-off-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20230629142228.1125715-1-bjorn@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-01riscv: vector: only enable interrupts in the first-use trapAndy Chiu
The function irqentry_exit_to_user_mode() must be called with interrupt disabled. The caller of do_trap_insn_illegal() also assumes running without interrupts. So, we should turn off interrupts after riscv_v_first_use_handler() returns. Fixes: cd054837243b ("riscv: Allocate user's vector context in the first-use trap") Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20230625155416.18629-1-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-22riscv: stack: Support HAVE_IRQ_EXIT_ON_IRQ_STACKGuo Ren
Add independent irq stacks for percpu to prevent kernel stack overflows. It is also compatible with VMAP_STACK by arch_alloc_vmap_stack. Tested-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@kernel.org> Cc: Clément Léger <cleger@rivosinc.com> Link: https://lore.kernel.org/r/20230614013018.2168426-2-guoren@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-08riscv: Allocate user's vector context in the first-use trapAndy Chiu
Vector unit is disabled by default for all user processes. Thus, a process will take a trap (illegal instruction) into kernel at the first time when it uses Vector. Only after then, the kernel allocates V context and starts take care of the context for that user process. Suggested-by: Richard Henderson <richard.henderson@linaro.org> Link: https://lore.kernel.org/r/3923eeee-e4dc-0911-40bf-84c34aee962d@linaro.org Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230605110724.21391-12-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-11riscv: entry: Save a0 prior syscall_enter_from_user_mode()Björn Töpel
The RISC-V calling convention passes the first argument, and the return value in the a0 register. For this reason, the a0 register needs some extra care; When handling syscalls, the a0 register is saved into regs->orig_a0, so a0 can be properly restored for, e.g. interrupted syscalls. This functionality was broken with the introduction of the generic entry patches. Here, a0 was saved into orig_a0 after calling syscall_enter_from_user_mode(), which can change regs->a0 for some paths, incorrectly restoring a0. This is resolved, by saving a0 prior doing the syscall_enter_from_user_mode() call. Fixes: f0bddf50586d ("riscv: entry: Convert to generic entry") Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Signed-off-by: Björn Töpel <bjorn@rivosinc.com> Reported-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Andy Chiu <andy.chiu@sifive.com> Link: https://lore.kernel.org/r/20230403065207.1070974-1-bjorn@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-03-23riscv: entry: Convert to generic entryGuo Ren
This patch converts riscv to use the generic entry infrastructure from kernel/entry/*. The generic entry makes maintainers' work easier and codes more elegant. Here are the changes: - More clear entry.S with handle_exception and ret_from_exception - Get rid of complex custom signal implementation - Move syscall procedure from assembly to C, which is much more readable. - Connect ret_from_fork & ret_from_kernel_thread to generic entry. - Wrap with irqentry_enter/exit and syscall_enter/exit_from_user_mode - Use the standard preemption code instead of custom Suggested-by: Huacai Chen <chenhuacai@kernel.org> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Yipeng Zou <zouyipeng@huawei.com> Tested-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@kernel.org> Cc: Ben Hutchings <ben@decadent.org.uk> Link: https://lore.kernel.org/r/20230222033021.983168-5-guoren@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-03-23riscv: entry: Add noinstr to prevent instrumentation insertedGuo Ren
Without noinstr the compiler is free to insert instrumentation (think all the k*SAN, KCov, GCov, ftrace etc..) which can call code we're not yet ready to run this early in the entry path, for instance it could rely on RCU which isn't on yet, or expect lockdep state. (by peterz) Link: https://lore.kernel.org/linux-riscv/YxcQ6NoPf3AH0EXe@hirez.programming.kicks-ass.net/ Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Suggested-by: Peter Zijlstra <peterz@infradead.org> Tested-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20230222033021.983168-4-guoren@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-02-21Merge patch series "riscv: Dump faulting instructions in oops handler"Palmer Dabbelt
Björn Töpel <bjorn@kernel.org> says: From: Björn Töpel <bjorn@rivosinc.com> RISC-V does not dump faulting instructions in the oops handler. This series adds "Code:" dumps to the oops output together with scripts/decodecode support. * b4-shazam-merge: scripts/decodecode: Add support for RISC-V riscv: Add instruction dump to RISC-V splats Link: https://lore.kernel.org/r/20230119074738.708301-1-bjorn@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-02-21riscv: Avoid enabling interrupts in die()Mattias Nissler
While working on something else, I noticed that the kernel would start accepting interrupts again after crashing in an interrupt handler. Since the kernel is already in inconsistent state, enabling interrupts is dangerous and opens up risk of kernel state deteriorating further. Interrupts do get enabled via what looks like an unintended side effect of spin_unlock_irq, so switch to the more cautious spin_lock_irqsave/spin_unlock_irqrestore instead. Fixes: 76d2a0493a17 ("RISC-V: Init and Halt Code") Signed-off-by: Mattias Nissler <mnissler@rivosinc.com> Reviewed-by: Björn Töpel <bjorn@kernel.org> Link: https://lore.kernel.org/r/20230215144828.3370316-1-mnissler@rivosinc.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-02-21riscv: Add instruction dump to RISC-V splatsBjörn Töpel
Add instruction dump (Code:) output to RISC-V splats. Dump 16b parcels. An example: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 Oops [#1] Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.2.0-rc3-00302-g840ff44c571d-dirty #27 Hardware name: riscv-virtio,qemu (DT) epc : kernel_init+0xc8/0x10e ra : kernel_init+0x70/0x10e epc : ffffffff80bd9a40 ra : ffffffff80bd99e8 sp : ff2000000060bec0 gp : ffffffff81730b28 tp : ff6000007ff00000 t0 : 7974697275636573 t1 : 0000000000000000 t2 : 3030303270393d6e s0 : ff2000000060bee0 s1 : ffffffff81732028 a0 : 0000000000000000 a1 : ff60000080dd1780 a2 : 0000000000000002 a3 : ffffffff8176a470 a4 : 0000000000000000 a5 : 000000000000000a a6 : 0000000000000081 a7 : ff60000080dd1780 s2 : 0000000000000000 s3 : 0000000000000000 s4 : 0000000000000000 s5 : 0000000000000000 s6 : 0000000000000000 s7 : 0000000000000000 s8 : 0000000000000000 s9 : 0000000000000000 s10: 0000000000000000 s11: 0000000000000000 t3 : ffffffff81186018 t4 : 0000000000000022 t5 : 000000000000003d t6 : 0000000000000000 status: 0000000200000120 badaddr: 0000000000000000 cause: 000000000000000f [<ffffffff80003528>] ret_from_exception+0x0/0x16 Code: 862a d179 608c a517 0069 0513 2be5 d0ef db2e 47a9 (c11c) a517 ---[ end trace 0000000000000000 ]--- Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b SMP: stopping secondary CPUs ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b ]--- Signed-off-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20230119074738.708301-2-bjorn@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-12-12Merge patch series "RISC-V: Align the shadow stack"Palmer Dabbelt
Palmer Dabbelt <palmer@rivosinc.com> says: This contains a pair of cleanups that depend on a fix that has already landed upstream. * b4-shazam-merge: RISC-V: Add some comments about the shadow and overflow stacks RISC-V: Align the shadow stack riscv: fix race when vmap stack overflow Link: https://lore.kernel.org/r/20221130023515.20217-1-palmer@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-12-12RISC-V: Add some comments about the shadow and overflow stacksPalmer Dabbelt
It took me a while to page all this back in when trying to review the recent spin_shadow_stack, so I figured I'd just write up some comments. Reviewed-by: Guo Ren <guoren@kernel.org> Reviewed-by: Jisheng Zhang <jszhang@kernel.org> Link: https://lore.kernel.org/r/20221130023515.20217-2-palmer@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-12-12RISC-V: Align the shadow stackPalmer Dabbelt
The standard RISC-V ABIs all require 16-byte stack alignment. We're only calling that one function on the shadow stack so I doubt it'd result in a real issue, but might as well keep this lined up. Fixes: 31da94c25aea ("riscv: add VMAP_STACK overflow detection") Reviewed-by: Jisheng Zhang <jszhang@kernel.org> Link: https://lore.kernel.org/r/20221130023515.20217-1-palmer@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-11-29riscv: fix race when vmap stack overflowJisheng Zhang
Currently, when detecting vmap stack overflow, riscv firstly switches to the so called shadow stack, then use this shadow stack to call the get_overflow_stack() to get the overflow stack. However, there's a race here if two or more harts use the same shadow stack at the same time. To solve this race, we introduce spin_shadow_stack atomic var, which will be swap between its own address and 0 in atomic way, when the var is set, it means the shadow_stack is being used; when the var is cleared, it means the shadow_stack isn't being used. Fixes: 31da94c25aea ("riscv: add VMAP_STACK overflow detection") Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Suggested-by: Guo Ren <guoren@kernel.org> Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20221030124517.2370-1-jszhang@kernel.org [Palmer: Add AQ to the swap, and also some comments.] Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-10-12RISC-V: Avoid dereferening NULL regs in die()Palmer Dabbelt
I don't think we can actually die() without a regs pointer, but the compiler was warning about a NULL check after a dereference. It seems prudent to just avoid the possibly-NULL dereference, given that when die()ing the system is already toast so who knows how we got there. Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20220920200037.6727-1-palmer@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-08-18riscv: traps: add missing prototypeConor Dooley
Sparse complains: arch/riscv/kernel/traps.c:213:6: warning: symbol 'shadow_stack' was not declared. Should it be static? The variable is used in entry.S, so declare shadow_stack there alongside SHADOW_OVERFLOW_STACK_SIZE. Fixes: 31da94c25aea ("riscv: add VMAP_STACK overflow detection") Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20220814141237.493457-5-mail@conchuod.ie Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-07-21RISC-V: Add fast call path of crash_kexec()Xianting Tian
Currently, almost all archs (x86, arm64, mips...) support fast call of crash_kexec() when "regs && kexec_should_crash()" is true. But RISC-V not, it can only enter crash system via panic(). However panic() doesn't pass the regs of the real accident scene to crash_kexec(), it caused we can't get accurate backtrace via gdb, $ riscv64-linux-gnu-gdb vmlinux vmcore Reading symbols from vmlinux... [New LWP 95] #0 console_unlock () at kernel/printk/printk.c:2557 2557 if (do_cond_resched) (gdb) bt #0 console_unlock () at kernel/printk/printk.c:2557 #1 0x0000000000000000 in ?? () With the patch we can get the accurate backtrace, $ riscv64-linux-gnu-gdb vmlinux vmcore Reading symbols from vmlinux... [New LWP 95] #0 0xffffffe00063a4e0 in test_thread (data=<optimized out>) at drivers/test_crash.c:81 81 *(int *)p = 0xdead; (gdb) (gdb) bt #0 0xffffffe00064d5c0 in test_thread (data=<optimized out>) at drivers/test_crash.c:81 #1 0x0000000000000000 in ?? () Test code to produce NULL address dereference in test_crash.c, void *p = NULL; *(int *)p = 0xdead; Reviewed-by: Guo Ren <guoren@kernel.org> Tested-by: Xianting Tian <xianting.tian@linux.alibaba.com> Signed-off-by: Xianting Tian <xianting.tian@linux.alibaba.com> Link: https://lore.kernel.org/r/20220606082308.2883458-1-xianting.tian@linux.alibaba.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-05-11riscv: integrate alternatives better into the main architectureHeiko Stuebner
Right now the alternatives need to be explicitly enabled and erratas are limited to SiFive ones. We want to use alternatives not only for patching soc erratas, but in the future also for handling different behaviour depending on the existence of future extensions. So move the core alternatives over to the kernel subdirectory and move the CONFIG_RISCV_ALTERNATIVE to be a hidden symbol which we expect relevant erratas and extensions to just select if needed. Signed-off-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Philipp Tomsich <philipp.tomsich@vrull.eu> Link: https://lore.kernel.org/r/20220511192921.2223629-2-heiko@sntech.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2021-12-13exit: Add and use make_task_dead.Eric W. Biederman
There are two big uses of do_exit. The first is it's design use to be the guts of the exit(2) system call. The second use is to terminate a task after something catastrophic has happened like a NULL pointer in kernel code. Add a function make_task_dead that is initialy exactly the same as do_exit to cover the cases where do_exit is called to handle catastrophic failure. In time this can probably be reduced to just a light wrapper around do_task_dead. For now keep it exactly the same so that there will be no behavioral differences introducing this new concept. Replace all of the uses of do_exit that use it for catastraphic task cleanup with make_task_dead to make it clear what the code is doing. As part of this rename rewind_stack_do_exit rewind_stack_and_make_dead. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-09-08trap: cleanup trap_init()Kefeng Wang
There are some empty trap_init() definitions in different ARCHs, Introduce a new weak trap_init() function to clean them up. Link: https://lkml.kernel.org/r/20210812123602.76356-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> [arm32] Acked-by: Vineet Gupta [arc] Acked-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc] Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Stafford Horne <shorne@gmail.com> Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com> Cc: Helge Deller <deller@gmx.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <palmerdabbelt@google.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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() ...
2021-07-06riscv: 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>
2021-06-10riscv: 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>
2021-05-06riscv: 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>
2021-05-06Merge 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 ...
2021-04-26riscv: 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>
2021-04-15riscv: add do_page_fault and do_trap_break into the kprobes blacklistJisheng Zhang
These two functions are used to implement the kprobes feature so they can't be kprobed. Fixes: c22b0bcb1dd0 ("riscv: Add kprobes supported") Cc: stable@vger.kernel.org Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-03-09riscv: traps: Fix no prototype warningsNanyong Sun
Fix all W=1 compilation warnings:'no previous prototype for' in arch/riscv/kernel/traps.c: arch/riscv/kernel/traps.c:96:15: warning: no previous prototype for ‘do_trap_unknown’ [-Wmissing-prototypes] 96 | DO_ERROR_INFO(do_trap_unknown, | ^~~~~~~~~~~~~~~ arch/riscv/kernel/traps.c:91:27: note: in definition of macro ‘DO_ERROR_INFO’ 91 | asmlinkage __visible void name(struct pt_regs *regs) \ | ^~~~ arch/riscv/kernel/traps.c:98:15: warning: no previous prototype for ‘do_trap_insn_misaligned’ [-Wmissing-prototypes] 98 | DO_ERROR_INFO(do_trap_insn_misaligned, | ^~~~~~~~~~~~~~~~~~~~~~~ arch/riscv/kernel/traps.c:91:27: note: in definition of macro ‘DO_ERROR_INFO’ 91 | asmlinkage __visible void name(struct pt_regs *regs) \ | ^~~~ arch/riscv/kernel/traps.c:100:15: warning: no previous prototype for ‘do_trap_insn_fault’ [-Wmissing-prototypes] ... Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> [Palmer: fix checkpatch warnings] Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-01-14riscv: Add dump stack in show_regsKefeng Wang
Like commit 1149aad10b1e ("arm64: Add dump_backtrace() in show_regs"), dump the stack in riscv show_regs as common code expects. Reviewed-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-01-14riscv: Add uprobes supportedGuo Ren
This patch adds support for uprobes on riscv architecture. Just like kprobe, it support single-step and simulate instructions. Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Reviewed-by: Pekka Enberg <penberg@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-01-14riscv: Add kprobes supportedGuo Ren
This patch enables "kprobe & kretprobe" to work with ftrace interface. It utilized software breakpoint as single-step mechanism. Some instructions which can't be single-step executed must be simulated in kernel execution slot, such as: branch, jal, auipc, la ... Some instructions should be rejected for probing and we use a blacklist to filter, such as: ecall, ebreak, ... We use ebreak & c.ebreak to replace origin instruction and the kprobe handler prepares an executable memory slot for out-of-line execution with a copy of the original instruction being probed. In execution slot we add ebreak behind original instruction to simulate a single-setp mechanism. The patch is based on packi's work [1] and csky's work [2]. - The kprobes_trampoline.S is all from packi's patch - The single-step mechanism is new designed for riscv without hw single-step trap - The simulation codes are from csky - Frankly, all codes refer to other archs' implementation [1] https://lore.kernel.org/linux-riscv/20181113195804.22825-1-me@packi.ch/ [2] https://lore.kernel.org/linux-csky/20200403044150.20562-9-guoren@kernel.org/ Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Co-developed-by: Patrick Stählin <me@packi.ch> Signed-off-by: Patrick Stählin <me@packi.ch> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Tested-by: Zong Li <zong.li@sifive.com> Reviewed-by: Pekka Enberg <penberg@kernel.org> Cc: Patrick Stählin <me@packi.ch> Cc: Palmer Dabbelt <palmerdabbelt@google.com> Cc: Björn Töpel <bjorn.topel@gmail.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-07-30RISC-V: Setup exception vector earlyAtish Patra
The trap vector is set only in trap_init which may be too late in some cases. Early ioremap/efi spits many warning messages which may be useful. Setup the trap vector early so that any warning/bug can be handled before generic code invokes trap_init. Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-06-18maccess: rename probe_kernel_address to get_kernel_nofaultChristoph Hellwig
Better describe what this helper does, and match the naming of copy_from_kernel_nofault. Also switch the argument order around, so that it acts and looks like get_user(). Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09irqchip: RISC-V per-HART local interrupt controller driverAnup Patel
The RISC-V per-HART local interrupt controller manages software interrupts, timer interrupts, external interrupts (which are routed via the platform level interrupt controller) and other per-HART local interrupts. We add a driver for the RISC-V local interrupt controller, which eventually replaces the RISC-V architecture code, allowing for a better split between arch code and drivers. The driver is compliant with RISC-V Hart-Level Interrupt Controller DT bindings located at: Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt Co-developed-by: Palmer Dabbelt <palmer@dabbelt.com> Signed-off-by: Anup Patel <anup.patel@wdc.com> [Palmer: Cleaned up warnings] Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2020-05-18riscv: Add KGDB supportVincent Chen
The skeleton of RISC-V KGDB port. Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
generated by cgit (git 2.34.1) at 2025-07-25 22:54:29 +0000