diff options
Diffstat (limited to 'kernel/trace/trace.c')
| -rw-r--r-- | kernel/trace/trace.c | 37 |
1 files changed, 30 insertions, 7 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 4509cf51fbfd..62e1befbad7f 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -26,6 +26,7 @@ #include <linux/linkage.h> #include <linux/uaccess.h> #include <linux/kprobes.h> +#include <linux/vmalloc.h> #include <linux/ftrace.h> #include <linux/module.h> #include <linux/percpu.h> @@ -1757,7 +1758,7 @@ void trace_buffer_unlock_commit(struct trace_array *tr, __buffer_unlock_commit(buffer, event); ftrace_trace_stack(tr, buffer, flags, 6, pc, NULL); - ftrace_trace_userstack(buffer, flags, pc); + ftrace_trace_userstack(tr, buffer, flags, pc); } EXPORT_SYMBOL_GPL(trace_buffer_unlock_commit); @@ -1819,7 +1820,7 @@ void trace_buffer_unlock_commit_regs(struct trace_array *tr, * two. They are that meaningful. */ ftrace_trace_stack(tr, buffer, flags, regs ? 0 : 4, pc, regs); - ftrace_trace_userstack(buffer, flags, pc); + ftrace_trace_userstack(tr, buffer, flags, pc); } EXPORT_SYMBOL_GPL(trace_buffer_unlock_commit_regs); @@ -1918,7 +1919,8 @@ static void __ftrace_trace_stack(struct ring_buffer *buffer, size *= sizeof(unsigned long); event = trace_buffer_lock_reserve(buffer, TRACE_STACK, - sizeof(*entry) + size, flags, pc); + (sizeof(*entry) - sizeof(entry->caller)) + size, + flags, pc); if (!event) goto out; entry = ring_buffer_event_data(event); @@ -1992,14 +1994,15 @@ void trace_dump_stack(int skip) static DEFINE_PER_CPU(int, user_stack_count); void -ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc) +ftrace_trace_userstack(struct trace_array *tr, + struct ring_buffer *buffer, unsigned long flags, int pc) { struct trace_event_call *call = &event_user_stack; struct ring_buffer_event *event; struct userstack_entry *entry; struct stack_trace trace; - if (!(global_trace.trace_flags & TRACE_ITER_USERSTACKTRACE)) + if (!(tr->trace_flags & TRACE_ITER_USERSTACKTRACE)) return; /* @@ -2323,6 +2326,9 @@ int trace_array_printk(struct trace_array *tr, if (!(global_trace.trace_flags & TRACE_ITER_PRINTK)) return 0; + if (!tr) + return -ENOENT; + va_start(ap, fmt); ret = trace_array_vprintk(tr, ip, fmt, ap); va_end(ap); @@ -5910,12 +5916,16 @@ static void buffer_pipe_buf_release(struct pipe_inode_info *pipe, buf->private = 0; } -static void buffer_pipe_buf_get(struct pipe_inode_info *pipe, +static bool buffer_pipe_buf_get(struct pipe_inode_info *pipe, struct pipe_buffer *buf) { struct buffer_ref *ref = (struct buffer_ref *)buf->private; + if (ref->ref > INT_MAX/2) + return false; + ref->ref++; + return true; } /* Pipe buffer operations for a buffer. */ @@ -6778,6 +6788,19 @@ static int allocate_trace_buffers(struct trace_array *tr, int size) */ allocate_snapshot = false; #endif + + /* + * Because of some magic with the way alloc_percpu() works on + * x86_64, we need to synchronize the pgd of all the tables, + * otherwise the trace events that happen in x86_64 page fault + * handlers can't cope with accessing the chance that a + * alloc_percpu()'d memory might be touched in the page fault trace + * event. Oh, and we need to audit all other alloc_percpu() and vmalloc() + * calls in tracing, because something might get triggered within a + * page fault trace event! + */ + vmalloc_sync_mappings(); + return 0; } @@ -7420,7 +7443,7 @@ __init static int tracer_alloc_buffers(void) goto out_free_buffer_mask; /* Only allocate trace_printk buffers if a trace_printk exists */ - if (__stop___trace_bprintk_fmt != __start___trace_bprintk_fmt) + if (&__stop___trace_bprintk_fmt != &__start___trace_bprintk_fmt) /* Must be called before global_trace.buffer is allocated */ trace_printk_init_buffers(); |