Ticket #6271: elf-support-for-images-with-a-single-rwx-PT_LOAD-pro.patch

src/system/kernel/elf.cpp

@@ -1959 +1959 @@
     size_t reservedSize;
     status_t status;
     ssize_t length;
+    bool textSectionWrittable = false;
 
     TRACE(("elf_load_kspace: entry path '%s'\n", path));
 
@@ -2099 +2100 @@
         }
 
         // we're here, so it must be a PT_LOAD segment
-        if (programHeaders[i].IsReadWrite()) {
+        if (programHeaders[i].IsExecutable()) {
+            // this is the non-writable segment
+            if (image->text_region.size != 0) {
+                // we've already created this segment
+                continue;
+            }
+            region = &image->text_region;
+
+            // some programs may have .text and .data concatenated in a
+            // single PT_LOAD section which is readable/writtable/executable
+            textSectionWrittable = programHeaders[i].IsReadWrite();
+
+            snprintf(regionName, B_OS_NAME_LENGTH, "%s_text", fileName);
+        } else if (programHeaders[i].IsReadWrite()) {
             // this is the writable segment
             if (image->data_region.size != 0) {
                 // we've already created this segment
@@ -2108 +2122 @@
             region = &image->data_region;
 
             snprintf(regionName, B_OS_NAME_LENGTH, "%s_data", fileName);
-        } else if (programHeaders[i].IsExecutable()) {
-            // this is the non-writable segment
-            if (image->text_region.size != 0) {
-                // we've already created this segment
-                continue;
-            }
-            region = &image->text_region;
-
-            snprintf(regionName, B_OS_NAME_LENGTH, "%s_text", fileName);
         } else {
             dprintf("%s: weird program header flags 0x%lx\n", fileName,
                 programHeaders[i].p_flags);
@@ -2185 +2190 @@
         goto error5;
 
     // We needed to read in the contents of the "text" area, but
-    // now we can protect it read-only/execute
+    // now we can protect it read-only/execute, unless this is a
+    // special image with concatenated .text and .data, when it
+    // will also nead write access.
     set_area_protection(image->text_region.id,
-        B_KERNEL_READ_AREA | B_KERNEL_EXECUTE_AREA);
+        B_KERNEL_READ_AREA | B_KERNEL_EXECUTE_AREA |
+        (textSectionWrittable ? B_KERNEL_WRITE_AREA : 0));
 
     // There might be a hole between the two segments, and we don't need to
     // reserve this any longer

headers/private/system/elf32.h

@@ -367 +367 @@
 inline bool
 Elf32_Phdr::IsExecutable() const
 {
-    return (p_flags & PF_PROTECTION_MASK) == (PF_READ | PF_EXECUTE);
+    return p_flags & PF_EXECUTE;
 }