[PATCH] D38872: [ExecutionEngine] Correct the size of a write in a COFF i386 relocation

[Alex Langford via Phabricator via llvm-commits]

xiaobai updated this revision to Diff 118967.
xiaobai added a comment.

Updated the test to ensure that this functionality is tested.


https://reviews.llvm.org/D38872

Files:
  lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldCOFFI386.h
  test/ExecutionEngine/RuntimeDyld/X86/COFF_i386.s


Index: test/ExecutionEngine/RuntimeDyld/X86/COFF_i386.s
===================================================================
--- test/ExecutionEngine/RuntimeDyld/X86/COFF_i386.s
+++ test/ExecutionEngine/RuntimeDyld/X86/COFF_i386.s
@@ -49,11 +49,6 @@
 	.long "_ExitProcess at 4"			// IMAGE_REL_I386_DIR32
 # rtdyld-check: *{4}__imp__ExitProcess = 0xffffffff
 
-	.global string
-	.align 1
-string:
-	.asciz "Hello World!\n"
-
 	.global relocations
 relocations:
 rel5:
@@ -63,8 +58,8 @@
 # rtdyld-check: *{2}rel6 = 1
 	.secidx __imp__OutputDebugStringA	// IMAGE_REL_I386_SECTION
 rel7:
-# rtdyld-check: *{4}rel7 = relocations - section_addr(COFF_i386.s.tmp.obj, .data)
-	.secrel32 relocations			// IMAGE_REL_I386_SECREL
+# rtdyld-check: *{4}rel7 = string - section_addr(COFF_i386.s.tmp.obj, .data)
+	.secrel32 string                        // IMAGE_REL_I386_SECREL
 
 # Test that addends work.
 rel8:
@@ -79,3 +74,12 @@
 rel11:
 # rtdyld-check: *{4}rel11 = string - section_addr(COFF_i386.s.tmp.obj, .data) + 1
 	.long string at SECREL32+1			// IMAGE_REL_I386_SECREL
+
+# We explicitly add padding to put string outside of the 16bit address space
+# (absolute and as an offset from .data), so that relocations involving
+# 32bit addresses / offsets are not accidentally truncated to 16 bits.
+        .space 65536
+        .global string
+        .align 1
+string:
+        .asciz "Hello World!\n"
Index: lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldCOFFI386.h
===================================================================
--- lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldCOFFI386.h
+++ lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldCOFFI386.h
@@ -209,7 +209,7 @@
       DEBUG(dbgs() << "\t\tOffset: " << RE.Offset
                    << " RelType: IMAGE_REL_I386_SECREL Value: " << RE.Addend
                    << '\n');
-      writeBytesUnaligned(RE.Addend, Target, 2);
+      writeBytesUnaligned(RE.Addend, Target, 4);
       break;
     default:
       llvm_unreachable("unsupported relocation type");


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