From f927b34a148b27b24f37f062d5a0620b76430ade Mon Sep 17 00:00:00 2001
From: Jordan Rupprecht <rupprecht@google.com>
Date: Mon, 12 Aug 2019 14:05:37 +0000
Subject: [PATCH] [llvm-readobj] Downgrade 'PT_DYNAMIC segment offset + size
 exceeds the size of the file' from an error to a warning

Summary: This allows llvm-readobj to print other useful information for truncated files instead of giving up.

Reviewers: jhenderson, grimar, MaskRay

Reviewed By: jhenderson, grimar, MaskRay

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66036

llvm-svn: 368576
---
 llvm/test/Object/invalid.test                              | 6 +++---
 llvm/test/tools/llvm-readobj/elf-malformed-pt-dynamic.test | 8 ++++----
 llvm/tools/llvm-readobj/ELFDumper.cpp                      | 6 ++++--
 3 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/llvm/test/Object/invalid.test b/llvm/test/Object/invalid.test
index 09c8dfe..cddc0b9 100644
--- a/llvm/test/Object/invalid.test
+++ b/llvm/test/Object/invalid.test
@@ -489,9 +489,9 @@ Sections:
 ## than the object size. Check llvm-readobj reports it.
 
 # RUN: yaml2obj %s --docnum=23 -o %t23
-# RUN: not llvm-readobj --dyn-relocations %t23 2>&1 | FileCheck --check-prefix=DYN-TABLE-PHDR %s
+# RUN: llvm-readobj --dyn-relocations %t23 2>&1 | FileCheck --check-prefix=DYN-TABLE-PHDR %s
 
-# DYN-TABLE-PHDR: error: PT_DYNAMIC segment offset + size exceeds the size of the file
+# DYN-TABLE-PHDR: warning: PT_DYNAMIC segment offset + size exceeds the size of the file
 
 --- !ELF
 FileHeader:
@@ -515,7 +515,7 @@ ProgramHeaders:
 ## than the object size. Check llvm-readobj reports it.
 
 # RUN: yaml2obj %s --docnum=24 -o %t24
-# RUN: not llvm-readobj --dyn-relocations %t24 2>&1 \
+# RUN: llvm-readobj --dyn-relocations %t24 2>&1 \
 # RUN:  | FileCheck --check-prefix=DYN-TABLE-PHDR %s
 
 --- !ELF
diff --git a/llvm/test/tools/llvm-readobj/elf-malformed-pt-dynamic.test b/llvm/test/tools/llvm-readobj/elf-malformed-pt-dynamic.test
index db229b1..c234d48 100644
--- a/llvm/test/tools/llvm-readobj/elf-malformed-pt-dynamic.test
+++ b/llvm/test/tools/llvm-readobj/elf-malformed-pt-dynamic.test
@@ -1,5 +1,5 @@
 # If the offset and/or size fields of the PT_DYNAMIC field become corrupted,
-# we should report a sensible error message.
+# we should report a sensible message.
 
 # Creating such a malformed file is hard. The easiest way to simulate it is to
 # truncate the file. Note that the section headers must first be stripped or
@@ -13,14 +13,14 @@
 # within the file.
 # RUN: cp %t.stripped %t.truncated1
 # RUN: %python -c "with open(r'%t.truncated1', 'r+') as f: f.truncate(0x1001)"
-# RUN: not llvm-readobj %t.truncated1 --dynamic-table 2>&1 | FileCheck %s
+# RUN: llvm-readobj %t.truncated1 --dynamic-table 2>&1 | FileCheck %s
 
 # Test case where the offset is too large to be in the file.
 # RUN: cp %t.stripped %t.truncated2
 # RUN: %python -c "with open(r'%t.truncated2', 'r+') as f: f.truncate(0xFFF)"
-# RUN: not llvm-readobj %t.truncated2 --dynamic-table 2>&1 | FileCheck %s
+# RUN: llvm-readobj %t.truncated2 --dynamic-table 2>&1 | FileCheck %s
 
-# CHECK: error: PT_DYNAMIC segment offset + size exceeds the size of the file
+# CHECK: warning: PT_DYNAMIC segment offset + size exceeds the size of the file
 
 --- !ELF
 FileHeader:
diff --git a/llvm/tools/llvm-readobj/ELFDumper.cpp b/llvm/tools/llvm-readobj/ELFDumper.cpp
index afff087..78216ef 100644
--- a/llvm/tools/llvm-readobj/ELFDumper.cpp
+++ b/llvm/tools/llvm-readobj/ELFDumper.cpp
@@ -1439,9 +1439,11 @@ void ELFDumper<ELFT>::loadDynamicTable(const ELFFile<ELFT> *Obj) {
     return;
 
   if (DynamicPhdr->p_offset + DynamicPhdr->p_filesz >
-      ObjF->getMemoryBufferRef().getBufferSize())
-    reportError(
+      ObjF->getMemoryBufferRef().getBufferSize()) {
+    reportWarning(
         "PT_DYNAMIC segment offset + size exceeds the size of the file");
+    return;
+  }
 
   if (!DynamicSec) {
     DynamicTable = createDRIFrom(DynamicPhdr, sizeof(Elf_Dyn));
-- 
2.7.4