improve logging to mention context.

Just printing the errno string such as "%m\n" is not enough to help
debug or users understand the problem.

Change to provide more context on the failing operation.

3 files changed, 15 insertions, 9 deletions

diff --git a/libkmod/libkmod-config.c b/libkmod/libkmod-config.c
index f970f9e..ac9c888 100644
--- a/libkmod/libkmod-config.c
+++ b/libkmod/libkmod-config.c
@@ -808,7 +808,7 @@ static int conf_files_list(struct kmod_ctx *ctx, struct kmod_list **list,
 
 	d = opendir(path);
 	if (d == NULL) {
-		ERR(ctx, "%m\n");
+		ERR(ctx, "opendir(%s): %m\n", path);
 		return -EINVAL;
 	}
 
diff --git a/libkmod/libkmod-index.c b/libkmod/libkmod-index.c
index c1c3c99..07f3b8c 100644
--- a/libkmod/libkmod-index.c
+++ b/libkmod/libkmod-index.c
@@ -788,12 +788,12 @@ struct index_mm *index_mm_open(struct kmod_ctx *ctx, const char *filename,
 
 	idx = malloc(sizeof(*idx));
 	if (idx == NULL) {
-		ERR(ctx, "%m\n");
+		ERR(ctx, "malloc: %m\n");
 		return NULL;
 	}
 
 	if ((fd = open(filename, O_RDONLY|O_CLOEXEC)) < 0) {
-		ERR(ctx, "%m\n");
+		ERR(ctx, "open(%s, O_RDONLY|O_CLOEXEC): %m\n", filename);
 		goto fail_open;
 	}
 
@@ -804,7 +804,8 @@ struct index_mm *index_mm_open(struct kmod_ctx *ctx, const char *filename,
 
 	if ((idx->mm = mmap(0, st.st_size, PROT_READ, flags, fd, 0))
 							== MAP_FAILED) {
-		ERR(ctx, "%m\n");
+		ERR(ctx, "mmap(0, %zd, PROT_READ, %d, %d, 0): %m\n",
+		    (size_t)st.st_size, flags, fd);
 		goto fail;
 	}
 
diff --git a/libkmod/libkmod.c b/libkmod/libkmod.c
index 9c7c701..4990d3e 100644
--- a/libkmod/libkmod.c
+++ b/libkmod/libkmod.c
@@ -441,7 +441,8 @@ static int kmod_lookup_alias_from_alias_bin(struct kmod_ctx *ctx,
 
 		err = kmod_module_new_from_alias(ctx, name, realname->value, &mod);
 		if (err < 0) {
-			ERR(ctx, "%s\n", strerror(-err));
+			ERR(ctx, "Could not create module for alias=%s realname=%s: %s\n",
+			    name, realname->value, strerror(-err));
 			goto fail;
 		}
 
@@ -524,7 +525,8 @@ int kmod_lookup_alias_from_moddep_file(struct kmod_ctx *ctx, const char *name,
 
 		n = kmod_module_new_from_name(ctx, name, &mod);
 		if (n < 0) {
-			ERR(ctx, "%s\n", strerror(-n));
+			ERR(ctx, "Could not create module from name %s: %s\n",
+			    name, strerror(-n));
 			goto finish;
 		}
 
@@ -555,7 +557,8 @@ int kmod_lookup_alias_from_config(struct kmod_ctx *ctx, const char *name,
 			err = kmod_module_new_from_alias(ctx, aliasname,
 								modname, &mod);
 			if (err < 0) {
-				ERR(ctx, "%s\n", strerror(-err));
+				ERR(ctx, "Could not create module for alias=%s modname=%s: %s\n",
+				    name, modname, strerror(-err));
 				goto fail;
 			}
 
@@ -587,7 +590,8 @@ int kmod_lookup_alias_from_commands(struct kmod_ctx *ctx, const char *name,
 
 			err = kmod_module_new_from_name(ctx, modname, &mod);
 			if (err < 0) {
-				ERR(ctx, "%s\n", strerror(-err));
+				ERR(ctx, "Could not create module from name %s: %s\n",
+				    modname, strerror(-err));
 				return err;
 			}
 
@@ -622,7 +626,8 @@ int kmod_lookup_alias_from_commands(struct kmod_ctx *ctx, const char *name,
 
 			err = kmod_module_new_from_name(ctx, modname, &mod);
 			if (err < 0) {
-				ERR(ctx, "%s\n", strerror(-err));
+				ERR(ctx, "Could not create module from name %s: %s\n",
+				    modname, strerror(-err));
 				return err;
 			}