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authorEduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>2009-03-23 09:12:22 -0400
committerIngo Molnar <mingo@elte.hu>2009-03-31 11:45:02 -0400
commitbdd6df6af98ce7e70702edfb5fd5dbbd8d1b0453 (patch)
treed590d52a6837e0201abf8fd4461fa177d3658a5a /kernel/trace
parent2a4efa42450762cbfa5c5712aa4cc9f06924c9fd (diff)
tracing: provide trace_seq_reserve()
trace_seq_reserve() allows a caller to reserve space in a trace_seq and write directly into it. This makes it easier to export binary data to userspace via the tracing interface, by simply filling in a struct. Signed-off-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/trace_output.c13
-rw-r--r--kernel/trace/trace_output.h1
2 files changed, 14 insertions, 0 deletions
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 19261fdd2455..6595074cbac5 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -167,6 +167,19 @@ int trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len)
167 return trace_seq_putmem(s, hex, j); 167 return trace_seq_putmem(s, hex, j);
168} 168}
169 169
170void *trace_seq_reserve(struct trace_seq *s, size_t len)
171{
172 void *ret;
173
174 if (len > ((PAGE_SIZE - 1) - s->len))
175 return NULL;
176
177 ret = s->buffer + s->len;
178 s->len += len;
179
180 return ret;
181}
182
170int trace_seq_path(struct trace_seq *s, struct path *path) 183int trace_seq_path(struct trace_seq *s, struct path *path)
171{ 184{
172 unsigned char *p; 185 unsigned char *p;
diff --git a/kernel/trace/trace_output.h b/kernel/trace/trace_output.h
index 35c422fb51a9..0ae20b83eec8 100644
--- a/kernel/trace/trace_output.h
+++ b/kernel/trace/trace_output.h
@@ -33,6 +33,7 @@ int trace_seq_puts(struct trace_seq *s, const char *str);
33int trace_seq_putc(struct trace_seq *s, unsigned char c); 33int trace_seq_putc(struct trace_seq *s, unsigned char c);
34int trace_seq_putmem(struct trace_seq *s, void *mem, size_t len); 34int trace_seq_putmem(struct trace_seq *s, void *mem, size_t len);
35int trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len); 35int trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len);
36void *trace_seq_reserve(struct trace_seq *s, size_t len);
36int trace_seq_path(struct trace_seq *s, struct path *path); 37int trace_seq_path(struct trace_seq *s, struct path *path);
37int seq_print_userip_objs(const struct userstack_entry *entry, 38int seq_print_userip_objs(const struct userstack_entry *entry,
38 struct trace_seq *s, unsigned long sym_flags); 39 struct trace_seq *s, unsigned long sym_flags);