kernel.git/arch/riscv/kernel/entry.S, branch linux-5.13.y

Merge tag 'riscv-for-linus-5.13-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

2021-05-06T16:24:18Z

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 ...

riscv: sifive: Apply errata "cip-453" patch

2021-04-26T15:24:57Z

Add sign extension to the $badaddr before addressing the instruction page fault and instruction access fault to workaround the issue "cip-453". To avoid affecting the existing code sequence, this patch will creates two trampolines to add sign extension to the $badaddr. By the "alternative" mechanism, these two trampolines will replace the original exception handler of instruction page fault and instruction access fault in the excp_vect_table. In this case, only the specific SiFive CPU core jumps to the do_page_fault and do_trap_insn_fault through these two trampolines. Other CPUs are not affected. Signed-off-by: Vincent Chen Signed-off-by: Palmer Dabbelt

riscv: keep interrupts disabled for BREAKPOINT exception

2021-04-16T04:32:40Z

Current riscv's kprobe handlers are run with both preemption and interrupt enabled, this violates kprobe requirements. Fix this issue by keeping interrupts disabled for BREAKPOINT exception. Fixes: c22b0bcb1dd0 ("riscv: Add kprobes supported") Cc: stable@vger.kernel.org Signed-off-by: Jisheng Zhang Reviewed-by: Masami Hiramatsu [Palmer: add a comment] Signed-off-by: Palmer Dabbelt

riscv,entry: fix misaligned base for excp_vect_table

2021-04-02T04:37:05Z

In RV64, the size of each entry in excp_vect_table is 8 bytes. If the base of the table is not 8-byte aligned, loading an entry in the table will raise a misaligned exception. Although such exception will be handled by opensbi/bbl, this still causes performance degradation. Signed-off-by: Zihao Yu Reviewed-by: Anup Patel Signed-off-by: Palmer Dabbelt

riscv: Trace irq on only interrupt is enabled

2021-01-13T04:16:35Z

We should call irq trace only if interrupt is going to be enabled during excecption handling. Otherwise, it results in following warning during boot with lock debugging enabled. [ 0.000000] ------------[ cut here ]------------ [ 0.000000] DEBUG_LOCKS_WARN_ON(early_boot_irqs_disabled) [ 0.000000] WARNING: CPU: 0 PID: 0 at kernel/locking/lockdep.c:4085 lockdep_hardirqs_on_prepare+0x22a/0x22e [ 0.000000] Modules linked in: [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.10.0-00022-ge20097fb37e2-dirty #548 [ 0.000000] epc: c005d5d4 ra : c005d5d4 sp : c1c01e80 [ 0.000000] gp : c1d456e0 tp : c1c0a980 t0 : 00000000 [ 0.000000] t1 : ffffffff t2 : 00000000 s0 : c1c01ea0 [ 0.000000] s1 : c100f360 a0 : 0000002d a1 : c00666ee [ 0.000000] a2 : 00000000 a3 : 00000000 a4 : 00000000 [ 0.000000] a5 : 00000000 a6 : c1c6b390 a7 : 3ffff00e [ 0.000000] s2 : c2384fe8 s3 : 00000000 s4 : 00000001 [ 0.000000] s5 : c1c0a980 s6 : c1d48000 s7 : c1613b4c [ 0.000000] s8 : 00000fff s9 : 80000200 s10: c1613b40 [ 0.000000] s11: 00000000 t3 : 00000000 t4 : 00000000 [ 0.000000] t5 : 00000001 t6 : 00000000 Fixes: 3c4697982982 ("riscv:Enable LOCKDEP_SUPPORT & fixup TRACE_IRQFLAGS_SUPPORT") Signed-off-by: Atish Patra Signed-off-by: Palmer Dabbelt

riscv: Enable interrupts during syscalls with M-Mode

2021-01-08T02:04:25Z

When running is M-Mode (no MMU config), MPIE does not get set. This results in all syscalls being executed with interrupts disabled as handle_exception never sets SR_IE as it always sees SR_PIE being cleared. Fix this by always force enabling interrupts in handle_syscall when CONFIG_RISCV_M_MODE is enabled. Signed-off-by: Damien Le Moal Reviewed-by: Palmer Dabbelt Signed-off-by: Palmer Dabbelt

riscv: return -ENOSYS for syscall -1

2021-01-08T02:01:34Z

Properly return -ENOSYS for syscall -1 instead of leaving the return value uninitialized. This fixes the strace teststuite. Fixes: 5340627e3fe0 ("riscv: add support for SECCOMP and SECCOMP_FILTER") Cc: stable@vger.kernel.org Signed-off-by: Andreas Schwab Reviewed-by: Tycho Andersen Signed-off-by: Palmer Dabbelt

riscv: Cleanup unnecessary define in asm-offset.c

2020-07-30T18:37:44Z

- TASK_THREAD_SP is duplicated define - TASK_STACK is no use at all - Don't worry about thread_info's offset in task_struct, have a look on comment in include/linux/sched.h: struct task_struct { /* * For reasons of header soup (see current_thread_info()), this * must be the first element of task_struct. */ struct thread_info thread_info; Signed-off-by: Guo Ren Signed-off-by: Palmer Dabbelt

riscv: Enable context tracking

2020-07-30T18:37:34Z

This patch implements and enables context tracking for riscv (which is a prerequisite for CONFIG_NO_HZ_FULL support) It adds checking for previous state in the entry that all excepttions and interrupts goes to and calls context_tracking_user_exit() if it comes from user space. It also calls context_tracking_user_enter() if it will return to user space before restore_all. This patch is tested with the dynticks-testing testcase in qemu-system-riscv64 virt machine and Unleashed board. git://git.kernel.org/pub/scm/linux/kernel/git/frederic/dynticks-testing.git We can see the log here. The tick got mostly stopped during the execution of the user loop. _-----=> irqs-off / _----=> need-resched | / _---=> hardirq/softirq || / _--=> preempt-depth ||| / delay TASK-PID CPU# |||| TIMESTAMP FUNCTION | | | |||| | | -0 [001] d..2 604.183512: sched_switch: prev_comm=swapper/1 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=taskset next_pid=273 next_prio=120 user_loop-273 [001] d.h1 604.184788: hrtimer_expire_entry: hrtimer=000000002eda5fab function=tick_sched_timer now=604176096300 user_loop-273 [001] d.s2 604.184897: workqueue_queue_work: work struct=00000000383402c2 function=vmstat_update workqueue=00000000f36d35d4 req_cpu=1 cpu=1 user_loop-273 [001] dns2 604.185039: tick_stop: success=0 dependency=SCHED user_loop-273 [001] dn.1 604.185103: tick_stop: success=0 dependency=SCHED user_loop-273 [001] d..2 604.185154: sched_switch: prev_comm=taskset prev_pid=273 prev_prio=120 prev_state=R+ ==> next_comm=kworker/1:1 next_pid=46 next_prio=120 <...>-46 [001] .... 604.185194: workqueue_execute_start: work struct 00000000383402c2: function vmstat_update <...>-46 [001] d..2 604.185266: sched_switch: prev_comm=kworker/1:1 prev_pid=46 prev_prio=120 prev_state=I ==> next_comm=taskset next_pid=273 next_prio=120 user_loop-273 [001] d.h1 604.188812: hrtimer_expire_entry: hrtimer=000000002eda5fab function=tick_sched_timer now=604180133400 user_loop-273 [001] d..1 604.189050: tick_stop: success=1 dependency=NONE user_loop-273 [001] d..2 614.251386: sched_switch: prev_comm=user_loop prev_pid=273 prev_prio=120 prev_state=X ==> next_comm=swapper/1 next_pid=0 next_prio=120 -0 [001] d..2 614.315391: sched_switch: prev_comm=swapper/1 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=taskset next_pid=276 next_prio=120 Signed-off-by: Greentime Hu Signed-off-by: Palmer Dabbelt

riscv: Enable LOCKDEP_SUPPORT & fixup TRACE_IRQFLAGS_SUPPORT

2020-07-30T18:37:32Z

Lockdep is needed by proving the spinlocks and rwlocks. To suupport it, we need fixup TRACE_IRQFLAGS_SUPPORT in kernel/entry.S. This patch follow Documentation/irqflags-tracing.txt. Signed-off-by: Guo Ren Signed-off-by: Palmer Dabbelt