[v10, 00/10] riscv: support kernel-mode Vector

[Björn Töpel]

Andy,

> Hello:
>
> This series was applied to riscv/linux.git (for-next)
> by Palmer Dabbelt <palmer at rivosinc.com>:
>

I'm getting some boot issues with this series applied to riscv/for-next.

The full runs (with logs) is here:
https://github.com/linux-riscv/linux-riscv/actions/runs/7498706326

Typically it fails in two ways:
Ubuntu rootfs:
--8<--
[ 4.346414] (sd-gens)[68]: Failed to extract file name from '': Invalid argument
[ 4.390832] systemd[1]: Failed to fork off sandboxing environment for executing generators: Protocol error
[ESC[0;1;31m!!!!!!ESC[0m] Failed to start up manager.
[ 4.440164] systemd[1]: Freezing execution.
--8<--

or:
--8<--
[   14.909912] (sd-gens)[71]: Assertion '!strv_isempty(dirs)' failed at src/shared/exec-util.c:211, function execute_directories(). Aborting.
[   15.008480] systemd[1]: Failed to fork off sandboxing environment for executing generators: Protocol error
[ESC[0;1;31m!!!!!!ESC[0m] Failed to start up manager.
[   15.111989] systemd[1]: Freezing execution.
--8<--

and Alpine with:
--8<--
[ 0.036703] Kernel panic - not syncing: kmem_cache_create_usercopy: Failed to create slab 'riscv_vector_ctx'. Error -22
[ 0.039195] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.7.0-rc1-defconfig_plain-gdf944704182e #1
[ 0.040744] Hardware name: riscv-virtio,qemu (DT)
[ 0.041975] Call Trace:
[ 0.042813] [<ffffffff800067a4>] dump_backtrace+0x1c/0x24
[ 0.044832] [<ffffffff80945980>] show_stack+0x2c/0x38
[ 0.045724] [<ffffffff80952214>] dump_stack_lvl+0x3c/0x54
[ 0.046841] [<ffffffff80952240>] dump_stack+0x14/0x1c
[ 0.047428] [<ffffffff80945e7c>] panic+0x106/0x29e
[ 0.047998] [<ffffffff8015f14c>] kmem_cache_create_usercopy+0x20e/0x258
[ 0.048786] [<ffffffff80a044dc>] riscv_v_setup_ctx_cache+0x2c/0x3c
[ 0.049521] [<ffffffff80a03a48>] arch_task_cache_init+0x10/0x18
[ 0.057832] [<ffffffff80a0706c>] fork_init+0x42/0x168
[ 0.058737] [<ffffffff80a00d70>] start_kernel+0x6ba/0x73a
--8<--

The Alpine boot can be fixed with something like:
--8<--
diff --git a/arch/riscv/kernel/vector.c b/arch/riscv/kernel/vector.c
index f9769703fd39..0ac79a9cdba5 100644
--- a/arch/riscv/kernel/vector.c
+++ b/arch/riscv/kernel/vector.c
@@ -53,6 +53,9 @@ int riscv_v_setup_vsize(void)
 
 void __init riscv_v_setup_ctx_cache(void)
 {
+       if (!riscv_v_vsize)
+               return;
+
        riscv_v_user_cachep = kmem_cache_create_usercopy("riscv_vector_ctx",
                                                         riscv_v_vsize, 16, SLAB_PANIC,
                                                         0, riscv_v_vsize, NULL);
--8<--

but with this "fix" in place I still get Ubuntu boot failures. To
reproduce the CI locally:

  | git fetch https://github.com/linux-riscv/linux-riscv e2aad75b340d65b0be4d1a689db3e10c6ed3f18e
  | git checkout FETCH_HEAD
  | docker pull ghcr.io/linux-riscv/pw-builder-multi:latest
  | docker run -it --volume $PWD:/build/my-linux ghcr.io/linux-riscv/pw-builder-multi:latest bash
  | # In container
  | bash -l
  | mkdir -p /build/kernels/logs
  | .github/scripts/series/prepare_tests.sh
  | cd /build/my-linux
  | .github/scripts/series/kernel_builder.sh rv64 defconfig plain gcc
  | .github/scripts/series/test_runner.sh rv64 defconfig plain gcc ubuntu
  | .github/scripts/series/test_runner.sh rv64 defconfig plain gcc alpine

Logs in /build/tests/run_test*

I'll continue to debug in the meantime.


Björn