libkmod: fix return error when opening index

When calling kmod_load_resources() we could end up getting a bogus
return value -ENOMEM due to several other reasons, like the index not
existing. Change index_mm_open() to propagate the failure reason so we
can take actions on it or return to the caller.

diff --git a/libkmod/libkmod-index.c b/libkmod/libkmod-index.c
index 1f3351a..6a34c8d 100644 (file)
--- a/libkmod/libkmod-index.c
+++ b/libkmod/libkmod-index.c
@@ -611,7 +611,7 @@ struct index_value *index_searchwild(struct index_file *in, const char *key)
 static const char _idx_empty_str[] = "";
 
 struct index_mm {
-       struct kmod_ctx *ctx;
+       const struct kmod_ctx *ctx;
        void *mm;
        uint32_t root_offset;
        size_t size;
@@ -739,10 +739,10 @@ static void index_mm_free_node(struct index_mm_node *node)
        free(node);
 }
 
-struct index_mm *index_mm_open(struct kmod_ctx *ctx, const char *filename,
-                                               unsigned long long *stamp)
+int index_mm_open(const struct kmod_ctx *ctx, const char *filename,
+                 unsigned long long *stamp, struct index_mm **pidx)
 {
-       int fd;
+       int fd, err;
        struct stat st;
        struct index_mm *idx;
        struct {
@@ -752,28 +752,32 @@ struct index_mm *index_mm_open(struct kmod_ctx *ctx, const char *filename,
        } hdr;
        void *p;
 
+       assert(pidx != NULL);
+
        DBG(ctx, "file=%s\n", filename);
 
        idx = malloc(sizeof(*idx));
        if (idx == NULL) {
                ERR(ctx, "malloc: %m\n");
-               return NULL;
+               return -ENOMEM;
        }
 
        if ((fd = open(filename, O_RDONLY|O_CLOEXEC)) < 0) {
                DBG(ctx, "open(%s, O_RDONLY|O_CLOEXEC): %m\n", filename);
+               err = -errno;
                goto fail_open;
        }
 
-       if (fstat(fd, &st) < 0)
-               goto fail_nommap;
-       if ((size_t) st.st_size < sizeof(hdr))
+       if (fstat(fd, &st) < 0 || (size_t) st.st_size < sizeof(hdr)) {
+               err = -EINVAL;
                goto fail_nommap;
+       }
 
-       if ((idx->mm = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0))
-                                                       == MAP_FAILED) {
+       idx->mm = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+       if (idx->mm == MAP_FAILED) {
                ERR(ctx, "mmap(NULL, %"PRIu64", PROT_READ, %d, MAP_PRIVATE, 0): %m\n",
                                                        st.st_size, fd);
+               err = -errno;
                goto fail_nommap;
        }
 
@@ -785,12 +789,14 @@ struct index_mm *index_mm_open(struct kmod_ctx *ctx, const char *filename,
        if (hdr.magic != INDEX_MAGIC) {
                ERR(ctx, "magic check fail: %x instead of %x\n", hdr.magic,
                                                                INDEX_MAGIC);
+               err = -EINVAL;
                goto fail;
        }
 
        if (hdr.version >> 16 != INDEX_VERSION_MAJOR) {
                ERR(ctx, "major version check fail: %u instead of %u\n",
                                        hdr.version >> 16, INDEX_VERSION_MAJOR);
+               err = -EINVAL;
                goto fail;
        }
 
@@ -800,8 +806,9 @@ struct index_mm *index_mm_open(struct kmod_ctx *ctx, const char *filename,
        close(fd);
 
        *stamp = stat_mstamp(&st);
+       *pidx = idx;
 
-       return idx;
+       return 0;
 
 fail:
        munmap(idx->mm, st.st_size);
@@ -809,7 +816,7 @@ fail_nommap:
        close(fd);
 fail_open:
        free(idx);
-       return NULL;
+       return err;
 }
 
 void index_mm_close(struct index_mm *idx)

diff --git a/libkmod/libkmod-index.h b/libkmod/libkmod-index.h
index 52aebac..db671b0 100644 (file)
--- a/libkmod/libkmod-index.h
+++ b/libkmod/libkmod-index.h
@@ -40,8 +40,8 @@ void index_values_free(struct index_value *values);
 
 /* Implementation using mmap */
 struct index_mm;
-struct index_mm *index_mm_open(struct kmod_ctx *ctx, const char *filename,
-                                               unsigned long long *stamp);
+int index_mm_open(const struct kmod_ctx *ctx, const char *filename,
+                 unsigned long long *stamp, struct index_mm **pidx);
 void index_mm_close(struct index_mm *index);
 char *index_mm_search(struct index_mm *idx, const char *key);
 struct index_value *index_mm_searchwild(struct index_mm *idx, const char *key);

diff --git a/libkmod/libkmod.c b/libkmod/libkmod.c
index 39f58d9..ab5c1e8 100644 (file)
--- a/libkmod/libkmod.c
+++ b/libkmod/libkmod.c
@@ -856,6 +856,7 @@ KMOD_EXPORT int kmod_validate_resources(struct kmod_ctx *ctx)
 KMOD_EXPORT int kmod_load_resources(struct kmod_ctx *ctx)
 {
        size_t i;
+       int ret;
 
        if (ctx == NULL)
                return -ENOENT;
@@ -871,17 +872,16 @@ KMOD_EXPORT int kmod_load_resources(struct kmod_ctx *ctx)
 
                snprintf(path, sizeof(path), "%s/%s.bin", ctx->dirname,
                                                        index_files[i].fn);
-               ctx->indexes[i] = index_mm_open(ctx, path,
-                                               &ctx->indexes_stamp[i]);
-               if (ctx->indexes[i] == NULL)
-                       goto fail;
+               ret = index_mm_open(ctx, path, &ctx->indexes_stamp[i],
+                                   &ctx->indexes[i]);
+               if (ret)
+                       break;
        }
 
-       return 0;
+       if (ret)
+               kmod_unload_resources(ctx);
 
-fail:
-       kmod_unload_resources(ctx);
-       return -ENOMEM;
+       return ret;
 }
 
 /**