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authorLennart Poettering <lennart@poettering.net>2014-01-22 13:06:04 +0100
committerLennart Poettering <lennart@poettering.net>2014-01-22 13:06:04 +0100
commit7f96b1d8147b164bc7c8ce119aeea5fed6ceecb7 (patch)
tree177dd946f66e5a4c9e0ebfe4b5b3456a5e7679cc /src/libsystemd
parent3736955368e8a3a24962f5fdd25cce3281885c30 (diff)
bus: extend memfd api so that we can label memfds for debugging purposes
Diffstat (limited to 'src/libsystemd')
-rw-r--r--src/libsystemd/libsystemd.sym1
-rw-r--r--src/libsystemd/sd-bus/sd-memfd.c117
-rw-r--r--src/libsystemd/sd-bus/test-bus-memfd.c10
-rw-r--r--src/libsystemd/sd-bus/test-bus-zero-copy.c4
4 files changed, 119 insertions, 13 deletions
diff --git a/src/libsystemd/libsystemd.sym b/src/libsystemd/libsystemd.sym
index 951166afa2..7798fac342 100644
--- a/src/libsystemd/libsystemd.sym
+++ b/src/libsystemd/libsystemd.sym
@@ -215,6 +215,7 @@ global:
sd_memfd_get_sealed;
sd_memfd_get_size;
sd_memfd_set_size;
+ sd_memfd_get_name;
/* sd-event functions */
sd_event_default;
diff --git a/src/libsystemd/sd-bus/sd-memfd.c b/src/libsystemd/sd-bus/sd-memfd.c
index 112c95fb43..913be2086a 100644
--- a/src/libsystemd/sd-bus/sd-memfd.c
+++ b/src/libsystemd/sd-bus/sd-memfd.c
@@ -23,22 +23,26 @@
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
+#include <sys/prctl.h>
#include "util.h"
#include "kdbus.h"
#include "sd-memfd.h"
+#include "sd-bus.h"
struct sd_memfd {
int fd;
FILE *f;
};
-_public_ int sd_memfd_new(sd_memfd **m) {
- struct kdbus_cmd_memfd_make cmd = {
- .size = sizeof(struct kdbus_cmd_memfd_make),
- };
+_public_ int sd_memfd_new(const char *name, sd_memfd **m) {
+
+ struct kdbus_cmd_memfd_make *cmd;
+ struct kdbus_item *item;
_cleanup_close_ int kdbus = -1;
+ _cleanup_free_ char *g = NULL;
+ size_t sz, l;
sd_memfd *n;
assert_return(m, -EINVAL);
@@ -47,16 +51,64 @@ _public_ int sd_memfd_new(sd_memfd **m) {
if (kdbus < 0)
return -errno;
- if (ioctl(kdbus, KDBUS_CMD_MEMFD_NEW, &cmd) < 0)
+ if (name) {
+ /* The kernel side is pretty picky about the character
+ * set here, let's do the usual bus escaping to deal
+ * with that. */
+
+ g = sd_bus_label_escape(name);
+ if (!g)
+ return -ENOMEM;
+
+ name = g;
+
+ } else {
+ char pr[17] = {};
+
+ /* If no name is specified we generate one. We include
+ * a hint indicating our library implementation, and
+ * add the thread name to it */
+
+ assert_se(prctl(PR_GET_NAME, (unsigned long) pr) >= 0);
+
+ if (isempty(pr))
+ name = "sd";
+ else {
+ _cleanup_free_ char *e = NULL;
+
+ e = sd_bus_label_escape(pr);
+ if (!e)
+ return -ENOMEM;
+
+ g = strappend("sd-", e);
+ if (!g)
+ return -ENOMEM;
+
+ name = g;
+ }
+ }
+
+ l = strlen(name);
+ sz = ALIGN8(offsetof(struct kdbus_cmd_memfd_make, items)) +
+ ALIGN8(offsetof(struct kdbus_item, str)) +
+ l + 1;
+ cmd = alloca0(sz);
+ cmd->size = sz;
+ item = cmd->items;
+ item->size = ALIGN8(offsetof(struct kdbus_item, str)) + l + 1;
+ item->type = KDBUS_ITEM_MEMFD_NAME;
+ memcpy(item->str, name, l + 1);
+
+ if (ioctl(kdbus, KDBUS_CMD_MEMFD_NEW, cmd) < 0)
return -errno;
n = new0(struct sd_memfd, 1);
if (!n) {
- close_nointr_nofail(cmd.fd);
+ close_nointr_nofail(cmd->fd);
return -ENOMEM;
}
- n->fd = cmd.fd;
+ n->fd = cmd->fd;
*m = n;
return 0;
}
@@ -195,11 +247,11 @@ _public_ int sd_memfd_set_size(sd_memfd *m, uint64_t sz) {
return r;
}
-_public_ int sd_memfd_new_and_map(sd_memfd **m, size_t sz, void **p) {
+_public_ int sd_memfd_new_and_map(const char *name, sd_memfd **m, size_t sz, void **p) {
sd_memfd *n;
int r;
- r = sd_memfd_new(&n);
+ r = sd_memfd_new(name, &n);
if (r < 0)
return r;
@@ -218,3 +270,50 @@ _public_ int sd_memfd_new_and_map(sd_memfd **m, size_t sz, void **p) {
*m = n;
return 0;
}
+
+_public_ int sd_memfd_get_name(sd_memfd *m, char **name) {
+ char path[sizeof("/proc/self/fd/") + DECIMAL_STR_MAX(int)], buf[FILENAME_MAX+1], *e;
+ const char *delim, *end;
+ _cleanup_free_ char *n = NULL;
+ ssize_t k;
+
+ assert_return(m, -EINVAL);
+ assert_return(name, -EINVAL);
+
+ sprintf(path, "/proc/self/fd/%i", m->fd);
+
+ k = readlink(path, buf, sizeof(buf));
+ if (k < 0)
+ return -errno;
+
+ if ((size_t) k >= sizeof(buf))
+ return -E2BIG;
+
+ buf[k] = 0;
+
+ delim = strstr(buf, ":[");
+ if (!delim)
+ return -EIO;
+
+ delim = strchr(delim + 2, ':');
+ if (!delim)
+ return -EIO;
+
+ delim++;
+
+ end = strchr(delim, ']');
+ if (!end)
+ return -EIO;
+
+ n = strndup(delim, end - delim);
+ if (!n)
+ return -ENOMEM;
+
+ e = sd_bus_label_unescape(n);
+ if (!e)
+ return -ENOMEM;
+
+ *name = e;
+
+ return 0;
+}
diff --git a/src/libsystemd/sd-bus/test-bus-memfd.c b/src/libsystemd/sd-bus/test-bus-memfd.c
index b9d6a250c3..f7197ed096 100644
--- a/src/libsystemd/sd-bus/test-bus-memfd.c
+++ b/src/libsystemd/sd-bus/test-bus-memfd.c
@@ -30,7 +30,7 @@
int main(int argc, char *argv[]) {
sd_memfd *m;
- char *s;
+ char *s, *name;
uint64_t sz;
int r, fd;
FILE *f;
@@ -40,10 +40,16 @@ int main(int argc, char *argv[]) {
log_set_max_level(LOG_DEBUG);
- r = sd_memfd_new(&m);
+ r = sd_memfd_new(NULL, &m);
if (r == -ENOENT)
return EXIT_TEST_SKIP;
+ assert_se(r >= 0);
+
+ assert_se(sd_memfd_get_name(m, &name) >= 0);
+ log_info("name: %s", name);
+ free(name);
+
r = sd_memfd_map(m, 0, 12, (void**) &s);
assert_se(r >= 0);
diff --git a/src/libsystemd/sd-bus/test-bus-zero-copy.c b/src/libsystemd/sd-bus/test-bus-zero-copy.c
index 5ad8ed54b0..a2239acaa4 100644
--- a/src/libsystemd/sd-bus/test-bus-zero-copy.c
+++ b/src/libsystemd/sd-bus/test-bus-zero-copy.c
@@ -93,7 +93,7 @@ int main(int argc, char *argv[]) {
memset(p+1, 'L', FIRST_ARRAY-2);
p[FIRST_ARRAY-1] = '>';
- r = sd_memfd_new_and_map(&f, STRING_SIZE, (void**) &s);
+ r = sd_memfd_new_and_map(NULL, &f, STRING_SIZE, (void**) &s);
assert_se(r >= 0);
s[0] = '<';
@@ -112,7 +112,7 @@ int main(int argc, char *argv[]) {
sd_memfd_free(f);
- r = sd_memfd_new_and_map(&f, SECOND_ARRAY, (void**) &p);
+ r = sd_memfd_new_and_map(NULL, &f, SECOND_ARRAY, (void**) &p);
assert_se(r >= 0);
p[0] = '<';