[DTrace-devel] [PATCH 20/26] libcommon: add uprobe_name() and uprobe_delete()
Kris Van Hees
kris.van.hees at oracle.com
Fri Oct 21 18:23:46 UTC 2022
Signed-off-by: Kris Van Hees <kris.van.hees at oracle.com>
---
libcommon/uprobes.c | 84 +++++++++++++++++++++++++++++++++------------
libcommon/uprobes.h | 2 ++
2 files changed, 64 insertions(+), 22 deletions(-)
diff --git a/libcommon/uprobes.c b/libcommon/uprobes.c
index 7e182797..bc4d1b2d 100644
--- a/libcommon/uprobes.c
+++ b/libcommon/uprobes.c
@@ -209,8 +209,21 @@ uprobe_decode_name(const char *name)
return decoded;
}
+char *
+uprobe_name(dev_t dev, ino_t ino, uint64_t addr, int isret)
+{
+ char *name;
+
+ if (asprintf(&name, "dt_pid/%c_%llx_%llx_%lx", isret ? 'r' : 'p',
+ (unsigned long long)dev, (unsigned long long)ino,
+ (unsigned long)addr) < 0)
+ return NULL;
+
+ return name;
+}
+
/*
- * Create a uprobe for a given mapping, address, and spec: the uprobe may be a
+ * Create a uprobe for a given device, address, and spec: the uprobe may be a
* uretprobe. Return the probe's name as a new dynamically-allocated string, or
* NULL on error. If prv/mod/fun/prb are all set, they are passed down as the
* name of the corresponding DTrace probe.
@@ -220,16 +233,9 @@ uprobe_create_named(dev_t dev, ino_t ino, uint64_t addr, const char *spec, int i
const char *prv, const char *mod, const char *fun,
const char *prb)
{
- int fd;
- int rc;
- char *name, *args = "";
-
- if (asprintf(&name, "dt_pid/%c_%llx_%llx_%lx",
- isret ? 'r' : 'p',
- (unsigned long long) dev,
- (unsigned long long) ino,
- (unsigned long) addr) < 0)
- return NULL;
+ int fd = -1;
+ int rc = -1;
+ char *name, *args = NULL;
if (prv && mod && fun && prb) {
char *eprv, *emod, *efun, *eprb;
@@ -244,8 +250,7 @@ uprobe_create_named(dev_t dev, ino_t ino, uint64_t addr, const char *spec, int i
if (asprintf(&args, "P%s=\\1 M%s=\\2 F%s=\\3 N%s=\\4",
eprv, emod, efun, eprb) < 0)
failed = 1;
- }
- else
+ } else
failed = 1;
free(eprv);
@@ -257,17 +262,24 @@ uprobe_create_named(dev_t dev, ino_t ino, uint64_t addr, const char *spec, int i
return NULL;
}
+ name = uprobe_name(dev, ino, addr, isret);
+ if (!name)
+ goto out;
+
/* Add the uprobe. */
fd = open(TRACEFS "uprobe_events", O_WRONLY | O_APPEND);
- if (fd != -1) {
- rc = dprintf(fd, "%c:%s %s %s\n", isret ? 'r' : 'p',
- name, spec, args);
+ if (fd == -1)
+ goto out;
- /* TODO: error reporting, probably via a callback */
- close(fd);
- }
+ rc = dprintf(fd, "%c:%s %s %s\n", isret ? 'r' : 'p', name, spec,
+ args ? args : "");
- if (fd == -1 || rc == -1) {
+out:
+ if (fd == -1)
+ close(fd);
+ free(args);
+ if (rc < 0) {
+ free(name);
return NULL;
}
@@ -283,8 +295,8 @@ uprobe_create_named(dev_t dev, ino_t ino, uint64_t addr, const char *spec, int i
char *
uprobe_create(dev_t dev, ino_t ino, uint64_t addr, const char *spec, int isret)
{
- return uprobe_create_named(dev, ino, addr, spec, isret,
- NULL, NULL, NULL, NULL);
+ return uprobe_create_named(dev, ino, addr, spec, isret,
+ NULL, NULL, NULL, NULL);
}
/*
@@ -309,3 +321,31 @@ uprobe_create_from_addr(pid_t pid, uint64_t addr, const char *prv,
free(spec);
return name;
}
+
+/*
+ * Destroy a uprobe for a given device, address, and spec.
+ */
+int
+uprobe_delete(dev_t dev, ino_t ino, uint64_t addr, int isret)
+{
+ int fd = -1;
+ int rc = -1;
+ char *name;
+
+ name = uprobe_name(dev, ino, addr, isret);
+ if (!name)
+ goto out;
+
+ fd = open(TRACEFS "uprobe_events", O_WRONLY | O_APPEND);
+ if (fd == -1)
+ goto out;
+
+ rc = dprintf(fd, "-:%s\n", name);
+
+out:
+ if (fd != -1)
+ close(fd);
+ free(name);
+
+ return rc < 0 ? -1 : 0;
+}
diff --git a/libcommon/uprobes.h b/libcommon/uprobes.h
index d99320cc..fde6ba40 100644
--- a/libcommon/uprobes.h
+++ b/libcommon/uprobes.h
@@ -15,6 +15,7 @@
extern char *uprobe_spec_by_addr(pid_t pid, ps_prochandle *P, uint64_t addr,
prmap_t *mapp);
+extern char *uprobe_name(dev_t dev, ino_t ino, uint64_t addr, int isret);
extern char *uprobe_create_named(dev_t dev, ino_t ino, uint64_t addr,
const char *spec, int isret, const char *prv,
const char *mod, const char *fun,
@@ -24,6 +25,7 @@ extern char *uprobe_create(dev_t dev, ino_t ino, uint64_t addr, const char *spec
extern char *uprobe_create_from_addr(pid_t pid, uint64_t addr, const char *prv,
const char *mod, const char *fun,
const char *prb);
+extern int uprobe_delete(dev_t dev, ino_t ino, uint64_t addr, int isret);
extern char *uprobe_encode_name(const char *);
extern char *uprobe_decode_name(const char *);
--
2.31.1
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