[Cbe-oss-dev] [PATCH] libspe2: Initialise object-id on isolated program load

[Jeremy Kerr]

When performing an isolated program load, we don't update the object-id
file, used for debugging and profiling. This changes does the write for
both isolated and non-isolated cases.

In the case of isolated contexts, we need to defer this loading until we
have received the appropriate stop code from the loader.

Signed-off-by: Jeremy Kerr <jk at ozlabs.org>

---

 spebase/create.c  |    1 +
 spebase/load.c    |   49 +++++++++++++++++++++++++++++++++++--------------
 spebase/run.c     |    2 +-
 spebase/spebase.h |   17 +++++++++++++++++
 4 files changed, 54 insertions(+), 15 deletions(-)

Index: libspe2/spebase/load.c
===================================================================
--- libspe2.orig/spebase/load.c
+++ libspe2/spebase/load.c
@@ -31,6 +31,34 @@
 #endif
 
 /**
+ * Register the SPE program's start address with the oprofile and gdb, by
+ * writing to the object-id file.
+ */
+void _base_spe_program_load_complete(spe_context_ptr_t spectx)
+{
+	int objfd, len;
+	char buf[20];
+	spe_program_handle_t *program;
+
+	program = spectx->base_private->loaded_program;
+
+	if (!program || !program->elf_image) {
+		DEBUG_PRINTF("%s called, but no program loaded\n", __func__);
+		return;
+	}
+
+	objfd = openat(spectx->base_private->fd_spe_dir, "object-id", O_RDWR);
+	if (objfd < 0)
+		return;
+
+	len = sprintf(buf, "%p", program->elf_image);
+	write(objfd, buf, len + 1);
+	close(objfd);
+
+	__spe_context_update_event();
+}
+
+/**
  * Send data to a SPU in mbox when space is available.
  *
  * Helper function for internal libspe use.
@@ -160,9 +188,11 @@ static int spe_start_emulated_isolated_a
 
 int _base_spe_program_load(spe_context_ptr_t spe, spe_program_handle_t *program)
 {
-	int rc = 0, objfd;
+	int rc = 0;
 	struct spe_ld_info ld_info;
 
+	spe->base_private->loaded_program = program;
+
 	if (spe->base_private->flags & SPE_ISOLATE) {
 		rc = spe_start_isolated_app(spe, program);
 
@@ -170,8 +200,10 @@ int _base_spe_program_load(spe_context_p
 		rc = spe_start_emulated_isolated_app(spe, program, &ld_info);
 
 	} else {
-		rc = _base_spe_load_spe_elf(program, spe->base_private->mem_mmap_base,
-					    &ld_info);
+		rc = _base_spe_load_spe_elf(program,
+				spe->base_private->mem_mmap_base, &ld_info);
+		if (!rc)
+			_base_spe_program_load_complete(spe);
 	}
 
 	if (rc != 0) {
@@ -179,17 +211,6 @@ int _base_spe_program_load(spe_context_p
 		return -1;
 	}
 
-	/* Register SPE image start address as "object-id" for oprofile.  */
-	objfd = openat (spe->base_private->fd_spe_dir,"object-id", O_RDWR);
-	if (objfd >= 0) {
-		char buf[100];
-		sprintf (buf, "%p", program->elf_image);
-		write (objfd, buf, strlen (buf) + 1);
-		close (objfd);
-	}
-	
-	__spe_context_update_event();	
-
 	spe->base_private->entry = ld_info.entry;
 	spe->base_private->emulated_entry = ld_info.entry;
 
Index: libspe2/spebase/create.c
===================================================================
--- libspe2.orig/spebase/create.c
+++ libspe2/spebase/create.c
@@ -223,6 +223,7 @@ spe_context_ptr_t _base_spe_context_crea
 	priv->cntl_mmap_base = MAP_FAILED;
 	priv->signal1_mmap_base = MAP_FAILED;
 	priv->signal2_mmap_base = MAP_FAILED;
+	priv->loaded_program = NULL;
 
 	for (i = 0; i < NUM_MBOX_FDS; i++) {
 		priv->spe_fds_array[i] = -1;
Index: libspe2/spebase/run.c
===================================================================
--- libspe2.orig/spebase/run.c
+++ libspe2/spebase/run.c
@@ -306,7 +306,7 @@ do_run:
 			 * and restart
 			 */
 			if (stopcode == SPE_PROGRAM_ISO_LOAD_COMPLETE) {
-				__spe_context_update_event();
+				_base_spe_program_load_complete(spe);
 				goto do_run;
 			} else {
 				stopinfo->stop_reason = SPE_ISOLATION_ERROR;
Index: libspe2/spebase/spebase.h
===================================================================
--- libspe2.orig/spebase/spebase.h
+++ libspe2/spebase/spebase.h
@@ -92,6 +92,12 @@ struct spe_context_base_priv {
 	/* SPE program entry point generated by elf_load() */
 	int		entry;
 
+	/* pointer to the program loaded/being loaded to the SPE. We need to
+	 * store this to allow deferred updates to gdb, when loading is
+	 * asynchronous (ie, isolated load, which is performed by the SPE).
+	 */
+	spe_program_handle_t *loaded_program;
+
 	/* We need to keep the entry point for emulated isolated contexts,
 	 * and ignore the value provided to spe_context_run */
 	int		emulated_entry;
@@ -188,6 +194,17 @@ extern spe_gang_context_ptr_t _base_spe_
 extern int _base_spe_program_load(spe_context_ptr_t spectx, spe_program_handle_t *program);
 
 /**
+ * Signal that the program load has completed. For normal apps, this is called
+ * directly in the load path. For (emulated) isolated apps, the load is
+ * asynchronous, so this needs to be called when we know that the load has
+ * completed
+ *
+ * @pre spe->base_priv->loaded_program is a valid SPE program
+ * @param spectx The spe context that has been loaded.
+ */
+void _base_spe_program_load_complete(spe_context_ptr_t spectx);
+
+/**
  * Check if the emulated loader is present in the filesystem
  * @return Non-zero if the loader is available, otherwise zero.
  */