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author | Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> | 2009-03-23 13:12:22 (GMT) |
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committer | Ingo Molnar <mingo@elte.hu> | 2009-03-31 15:45:02 (GMT) |
commit | bdd6df6af98ce7e70702edfb5fd5dbbd8d1b0453 (patch) | |
tree | d590d52a6837e0201abf8fd4461fa177d3658a5a /kernel/trace | |
parent | 2a4efa42450762cbfa5c5712aa4cc9f06924c9fd (diff) | |
download | linux-fsl-qoriq-bdd6df6af98ce7e70702edfb5fd5dbbd8d1b0453.tar.xz |
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.c | 13 | ||||
-rw-r--r-- | kernel/trace/trace_output.h | 1 |
2 files changed, 14 insertions, 0 deletions
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index 19261fd..6595074 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) return trace_seq_putmem(s, hex, j); } +void *trace_seq_reserve(struct trace_seq *s, size_t len) +{ + void *ret; + + if (len > ((PAGE_SIZE - 1) - s->len)) + return NULL; + + ret = s->buffer + s->len; + s->len += len; + + return ret; +} + int trace_seq_path(struct trace_seq *s, struct path *path) { unsigned char *p; diff --git a/kernel/trace/trace_output.h b/kernel/trace/trace_output.h index 35c422f..0ae20b8 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); int trace_seq_putc(struct trace_seq *s, unsigned char c); int trace_seq_putmem(struct trace_seq *s, void *mem, size_t len); int trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len); +void *trace_seq_reserve(struct trace_seq *s, size_t len); int trace_seq_path(struct trace_seq *s, struct path *path); int seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s, unsigned long sym_flags); |