ksym_tracer: Support read accesses independent of read/write.

All of the infrastructure already exists to support read accesses
for platforms that support a read access independently of read/write
(such as in the case of the SuperH UBC). This just trivially hooks
up the read case by itself.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Prasad <prasad@linux.vnet.ibm.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jan Kiszka <jan.kiszka@web.de>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
LKML-Reference: <20091109083733.GA25848@linux-sh.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

1 files changed, 10 insertions, 1 deletions

diff --git a/kernel/trace/trace_ksym.c b/kernel/trace/trace_ksym.c
index fea83eeeef09..11935b53a6cb 100644
--- a/kernel/trace/trace_ksym.c
+++ b/kernel/trace/trace_ksym.c
@@ -136,6 +136,7 @@ static int ksym_trace_get_access_type(char *str)
                 access |= HW_BREAKPOINT_X;
 
         switch (access) {
+        case HW_BREAKPOINT_R:
         case HW_BREAKPOINT_W:
         case HW_BREAKPOINT_W | HW_BREAKPOINT_R:
                 return access;
@@ -239,7 +240,9 @@ static ssize_t ksym_trace_filter_read(struct file *filp, char __user *ubuf,
 
         hlist_for_each_entry(entry, node, &ksym_filter_head, ksym_hlist) {
                 ret = trace_seq_printf(s, "%pS:", (void *)entry->ksym_addr);
-                if (entry->type == HW_BREAKPOINT_W)
+                if (entry->type == HW_BREAKPOINT_R)
+                        ret = trace_seq_puts(s, "r--\n");
+                else if (entry->type == HW_BREAKPOINT_W)
                         ret = trace_seq_puts(s, "-w-\n");
                 else if (entry->type == (HW_BREAKPOINT_W | HW_BREAKPOINT_R))
                         ret = trace_seq_puts(s, "rw-\n");
@@ -414,6 +417,9 @@ static enum print_line_t ksym_trace_output(struct trace_iterator *iter)
                 return TRACE_TYPE_PARTIAL_LINE;
 
         switch (field->type) {
+        case HW_BREAKPOINT_R:
+                ret = trace_seq_printf(s, " R  ");
+                break;
         case HW_BREAKPOINT_W:
                 ret = trace_seq_printf(s, " W  ");
                 break;
@@ -488,6 +494,9 @@ static int ksym_tracer_stat_show(struct seq_file *m, void *v)
         access_type = entry->type;
 
         switch (access_type) {
+        case HW_BREAKPOINT_R:
+                seq_puts(m, "  R           ");
+                break;
         case HW_BREAKPOINT_W:
                 seq_puts(m, "  W           ");
                 break;