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authorKefeng Wang <wangkefeng.wang@huawei.com>2020-12-22 19:01:52 +0300
committerPalmer Dabbelt <palmerdabbelt@google.com>2021-01-13 07:25:32 +0300
commit80709af7325d179b433817f421c85449f2454046 (patch)
tree69bddb8d4eab09de98102a39d574915981dccf85 /arch
parent7cd1af107a92eb63b93a96dc07406dcbc5269436 (diff)
downloadlinux-80709af7325d179b433817f421c85449f2454046.tar.xz
riscv: cacheinfo: Fix using smp_processor_id() in preemptible
Use raw_smp_processor_id instead of smp_processor_id() to fix warning, BUG: using smp_processor_id() in preemptible [00000000] code: init/1 caller is debug_smp_processor_id+0x1c/0x26 CPU: 0 PID: 1 Comm: init Not tainted 5.10.0-rc4 #211 Call Trace: walk_stackframe+0x0/0xaa show_stack+0x32/0x3e dump_stack+0x76/0x90 check_preemption_disabled+0xaa/0xac debug_smp_processor_id+0x1c/0x26 get_cache_size+0x18/0x68 load_elf_binary+0x868/0xece bprm_execve+0x224/0x498 kernel_execve+0xdc/0x142 run_init_process+0x90/0x9e try_to_run_init_process+0x12/0x3c kernel_init+0xb4/0xf8 ret_from_exception+0x0/0xc The issue is found when CONFIG_DEBUG_PREEMPT enabled. Reviewed-by: Atish Patra <atish.patra@wdc.com> Tested-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> [Palmer: Added a comment.] Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/riscv/kernel/cacheinfo.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/arch/riscv/kernel/cacheinfo.c b/arch/riscv/kernel/cacheinfo.c
index de59dd457b41..d86781357044 100644
--- a/arch/riscv/kernel/cacheinfo.c
+++ b/arch/riscv/kernel/cacheinfo.c
@@ -26,7 +26,16 @@ cache_get_priv_group(struct cacheinfo *this_leaf)
static struct cacheinfo *get_cacheinfo(u32 level, enum cache_type type)
{
- struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(smp_processor_id());
+ /*
+ * Using raw_smp_processor_id() elides a preemptability check, but this
+ * is really indicative of a larger problem: the cacheinfo UABI assumes
+ * that cores have a homonogenous view of the cache hierarchy. That
+ * happens to be the case for the current set of RISC-V systems, but
+ * likely won't be true in general. Since there's no way to provide
+ * correct information for these systems via the current UABI we're
+ * just eliding the check for now.
+ */
+ struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(raw_smp_processor_id());
struct cacheinfo *this_leaf;
int index;