Changeset c0393db in mainline

Timestamp:

2015-04-04T21:14:22Z (9 years ago)

Author:

Maurizio Lombardi <m.lombardi85@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

6efd162

Parents:

43523b1

Message:

isa: read() is not guaranteed to read all the bytes requested.

This wrong assumption prevented the isa driver from loading part of the configuration file when using FAT as root filesystem.

File:

• uspace/drv/bus/isa/isa.c (modified) (4 diffs)

uspace/drv/bus/isa/isa.c

@@ -245 +245 @@
         bool opened = false;
         int fd;
-        size_t len = 0;
+        size_t file_len;
+        size_t total_read = 0;
+        ssize_t r;
 
         fd = open(conf_path, O_RDONLY);
@@ -255 +257 @@
         opened = true;
 
-        len = lseek(fd, 0, SEEK_END);
+        file_len = lseek(fd, 0, SEEK_END);
         lseek(fd, 0, SEEK_SET);
-        if (len == 0) {
+        if (file_len == 0) {
                 ddf_msg(LVL_ERROR, "Configuration file '%s' is empty.",
                     conf_path);
@@ -263 +265 @@
         }
 
-        buf = malloc(len + 1);
+        buf = malloc(file_len + 1);
         if (buf == NULL) {
                 ddf_msg(LVL_ERROR, "Memory allocation failed.");
@@ -269 +271 @@
         }
 
-        if (0 >= read(fd, buf, len)) {
-                ddf_msg(LVL_ERROR, "Unable to read file '%s'.", conf_path);
-                goto cleanup;
-        }
-
-        buf[len] = 0;
+        do {
+                r = read(fd, &buf[total_read], file_len - total_read);
+                if (r < 0) {
+                        ddf_msg(LVL_ERROR, "Unable to read file '%s'.", conf_path);
+                        goto cleanup;
+                }
+
+                total_read += r;
+        } while (total_read < file_len);
+
+        buf[file_len] = 0;
 
         suc = true;