diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 96129985e81c..e58b72e61573 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -8492,6 +8492,10 @@ static int tracing_buffers_mmap(struct file *filp, struct vm_area_struct *vma) struct trace_iterator *iter = &info->iter; int ret = 0; + /* A memmap'ed buffer is not supported for user space mmap */ + if (iter->tr->flags & TRACE_ARRAY_FL_MEMMAP) + return -ENODEV; + /* Currently the boot mapped buffer is not supported for mmap */ if (iter->tr->flags & TRACE_ARRAY_FL_BOOT) return -ENODEV; @@ -9600,9 +9604,6 @@ static void free_trace_buffers(struct trace_array *tr) #ifdef CONFIG_TRACER_MAX_TRACE free_trace_buffer(&tr->max_buffer); #endif - - if (tr->range_addr_start) - vunmap((void *)tr->range_addr_start); } static void init_trace_flags_index(struct trace_array *tr) @@ -10696,6 +10697,7 @@ static inline void do_allocate_snapshot(const char *name) { } __init static void enable_instances(void) { struct trace_array *tr; + bool memmap_area = false; char *curr_str; char *name; char *str; @@ -10764,6 +10766,7 @@ __init static void enable_instances(void) name); continue; } + memmap_area = true; } else if (tok) { if (!reserve_mem_find_by_name(tok, &start, &size)) { start = 0; @@ -10784,7 +10787,10 @@ __init static void enable_instances(void) continue; } - addr = map_pages(start, size); + if (memmap_area) + addr = map_pages(start, size); + else + addr = (unsigned long)phys_to_virt(start); if (addr) { pr_info("Tracing: mapped boot instance %s at physical memory %pa of size 0x%lx\n", name, &start, (unsigned long)size); @@ -10811,10 +10817,13 @@ __init static void enable_instances(void) update_printk_trace(tr); /* - * If start is set, then this is a mapped buffer, and - * cannot be deleted by user space, so keep the reference - * to it. + * memmap'd buffers can not be freed. */ + if (memmap_area) { + tr->flags |= TRACE_ARRAY_FL_MEMMAP; + tr->ref++; + } + if (start) { tr->flags |= TRACE_ARRAY_FL_BOOT | TRACE_ARRAY_FL_LAST_BOOT; tr->range_name = no_free_ptr(rname); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index ab7c7a1930cc..9d9dcfad6269 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -446,6 +446,7 @@ enum { TRACE_ARRAY_FL_BOOT = BIT(1), TRACE_ARRAY_FL_LAST_BOOT = BIT(2), TRACE_ARRAY_FL_MOD_INIT = BIT(3), + TRACE_ARRAY_FL_MEMMAP = BIT(4), }; #ifdef CONFIG_MODULES