Introduce headers before each file section, in trace file version 7. The
section header has the following format:
<2 bytes>, header ID
<2 bytes>, section flags:
1: the section is compressed
<4 bytes>, offset within the strings section, where the section
description string is located.
<8 bytes>, size of the section
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@xxxxxxxxx>
---
include/trace-cmd/trace-cmd.h | 5 ++
.../include/private/trace-cmd-private.h | 1 +
lib/trace-cmd/include/trace-cmd-local.h | 5 ++
lib/trace-cmd/trace-output.c | 77 ++++++++++++++++++-
4 files changed, 87 insertions(+), 1 deletion(-)
diff --git a/include/trace-cmd/trace-cmd.h b/include/trace-cmd/trace-cmd.h
index 7fea4e01..5d71e8ba 100644
--- a/include/trace-cmd/trace-cmd.h
+++ b/include/trace-cmd/trace-cmd.h
@@ -15,6 +15,11 @@ enum tracecmd_open_flags {
TRACECMD_FL_LOAD_NO_PLUGINS = 1 << 0, /* Do not load plugins */
TRACECMD_FL_LOAD_NO_SYSTEM_PLUGINS = 1 << 1, /* Do not load system plugins */
};
+
+enum tracecmd_section_flags {
+ TRACECMD_SEC_FL_COMPRESS = 1 << 0, /* the section is compressed */
+};
+
struct tracecmd_input *tracecmd_open_head(const char *file, int flags);
struct tracecmd_input *tracecmd_open(const char *file, int flags);
struct tracecmd_input *tracecmd_open_fd(int fd, int flags);
diff --git a/lib/trace-cmd/include/private/trace-cmd-private.h b/lib/trace-cmd/include/private/trace-cmd-private.h
index e1467971..2eb077c8 100644
--- a/lib/trace-cmd/include/private/trace-cmd-private.h
+++ b/lib/trace-cmd/include/private/trace-cmd-private.h
@@ -144,6 +144,7 @@ enum {
TRACECMD_OPTION_GUEST,
TRACECMD_OPTION_TSC2NSEC,
TRACECMD_OPTION_STRINGS,
+ TRACECMD_OPTION_MAX,
};
enum {
diff --git a/lib/trace-cmd/include/trace-cmd-local.h b/lib/trace-cmd/include/trace-cmd-local.h
index 7f280533..4a0a691c 100644
--- a/lib/trace-cmd/include/trace-cmd-local.h
+++ b/lib/trace-cmd/include/trace-cmd-local.h
@@ -39,6 +39,11 @@ struct data_file_write {
bool check_file_state(unsigned long file_version, int current_state, int new_state);
bool check_out_state(struct tracecmd_output *handle, int new_state);
+unsigned long long
+out_write_section_header(struct tracecmd_output *handle, unsigned short header_id,
+ char *description, int flags, bool option);
+int out_update_section_header(struct tracecmd_output *handle, unsigned long long offset);
+
struct cpu_data_source {
int fd;
int size;
diff --git a/lib/trace-cmd/trace-output.c b/lib/trace-cmd/trace-output.c
index d3c73ceb..e1803dbd 100644
--- a/lib/trace-cmd/trace-output.c
+++ b/lib/trace-cmd/trace-output.c
@@ -365,6 +365,82 @@ int tracecmd_ftrace_enable(int set)
return ret;
}
+__hidden unsigned long long
+out_write_section_header(struct tracecmd_output *handle, unsigned short header_id,
+ char *description, int flags, bool option)
+{
+ tsize_t endian8;
+ tsize_t offset;
+ long long size;
+ short endian2;
+ int endian4;
+ int desc;
+
+ if (header_id >= TRACECMD_OPTION_MAX)
+ return -1;
+ if (!HAS_SECTIONS(handle))
+ return 0;
+ offset = do_lseek(handle, 0, SEEK_CUR);
+ if (option) {
+ endian8 = convert_endian_8(handle, offset);
+ if (!tracecmd_add_option(handle, header_id, 8, &endian8))
+ return -1;
+ }
+ /* Section ID */
+ endian2 = convert_endian_2(handle, header_id);
+ if (do_write_check(handle, &endian2, 2))
+ return (off64_t)-1;
+
+ /* Section flags */
+ endian2 = convert_endian_2(handle, flags);
+ if (do_write_check(handle, &endian2, 2))
+ return (off64_t)-1;
+
+ /* Section description */
+ if (description)
+ desc = add_string(handle, description);
+ else
+ desc = -1;
+ endian4 = convert_endian_4(handle, desc);
+ if (do_write_check(handle, &endian4, 4))
+ return (off64_t)-1;
+
+ offset = do_lseek(handle, 0, SEEK_CUR);
+ size = 0;
+ /* Reserve for section size */
+ if (do_write_check(handle, &size, 8))
+ return (off64_t)-1;
+ return offset;
+}
+
+__hidden int out_update_section_header(struct tracecmd_output *handle, tsize_t offset)
+{
+ tsize_t current;
+ tsize_t endian8;
+ tsize_t size;
+
+ if (!HAS_SECTIONS(handle) || offset == 0)
+ return 0;
+
+ current = do_lseek(handle, 0, SEEK_CUR);
+ /* The real size is the difference between the saved offset and
+ * the current offset - 8 bytes, the reserved space for the section size.
+ */
+ size = current - offset;
+ if (size < 8)
+ return -1;
+ size -= 8;
+ if (do_lseek(handle, offset, SEEK_SET) == (off64_t)-1)
+ return -1;
+
+ endian8 = convert_endian_8(handle, size);
+ if (do_write_check(handle, &endian8, 8))
+ return -1;
+ if (do_lseek(handle, current, SEEK_SET) == (off64_t)-1)
+ return -1;
+ return 0;
+}
+
static int save_string_section(struct tracecmd_output *handle)
{
if (!handle->strings || !handle->strings_p)
@@ -390,7 +466,6 @@ error:
return -1;
}
-
static int read_header_files(struct tracecmd_output *handle)
{
tsize_t size, check_size, endian8;
--
2.34.1
|