Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

release/18.x: [LLD] [COFF] Set the right alignment for DelayDirectoryChunk (#84697) #84844

Merged
merged 1 commit into from
Mar 13, 2024

Conversation

llvmbot
Copy link
Collaborator

@llvmbot llvmbot commented Mar 11, 2024

Backport c93c76b

Requested by: @mstorsjo

@llvmbot llvmbot added this to the LLVM 18.X Release milestone Mar 11, 2024
@llvmbot
Copy link
Collaborator Author

llvmbot commented Mar 11, 2024

@cjacek What do you think about merging this PR to the release branch?

@llvmbot
Copy link
Collaborator Author

llvmbot commented Mar 11, 2024

@llvm/pr-subscribers-lld-coff
@llvm/pr-subscribers-platform-windows

@llvm/pr-subscribers-lld

Author: None (llvmbot)

Changes

Backport c93c76b

Requested by: @mstorsjo


Full diff: https://github.com/llvm/llvm-project/pull/84844.diff

2 Files Affected:

  • (modified) lld/COFF/DLL.cpp (+1-1)
  • (modified) lld/test/COFF/delayimports-armnt.yaml (+19-6)
diff --git a/lld/COFF/DLL.cpp b/lld/COFF/DLL.cpp
index 6b516d8c6d5ef8..c4388ba9e40d0b 100644
--- a/lld/COFF/DLL.cpp
+++ b/lld/COFF/DLL.cpp
@@ -172,7 +172,7 @@ binImports(COFFLinkerContext &ctx,
 // A chunk for the delay import descriptor table etnry.
 class DelayDirectoryChunk : public NonSectionChunk {
 public:
-  explicit DelayDirectoryChunk(Chunk *n) : dllName(n) {}
+  explicit DelayDirectoryChunk(Chunk *n) : dllName(n) { setAlignment(4); }
 
   size_t getSize() const override {
     return sizeof(delay_import_directory_table_entry);
diff --git a/lld/test/COFF/delayimports-armnt.yaml b/lld/test/COFF/delayimports-armnt.yaml
index 7d9bc38c5c3606..ea96d864ef53d5 100644
--- a/lld/test/COFF/delayimports-armnt.yaml
+++ b/lld/test/COFF/delayimports-armnt.yaml
@@ -6,6 +6,7 @@
 # RUN: llvm-readobj --coff-imports %t.exe | FileCheck -check-prefix=IMPORT %s
 # RUN: llvm-readobj --coff-basereloc %t.exe | FileCheck -check-prefix=BASEREL %s
 # RUN: llvm-objdump --no-print-imm-hex -d %t.exe | FileCheck --check-prefix=DISASM %s
+# RUN: llvm-readobj --file-headers %t.exe | FileCheck -check-prefix=DIR %s
 
 # IMPORT:      Format: COFF-ARM
 # IMPORT-NEXT: Arch: thumb
@@ -13,9 +14,9 @@
 # IMPORT-NEXT: DelayImport {
 # IMPORT-NEXT:   Name: library.dll
 # IMPORT-NEXT:   Attributes: 0x1
-# IMPORT-NEXT:   ModuleHandle: 0x3000
-# IMPORT-NEXT:   ImportAddressTable: 0x3008
-# IMPORT-NEXT:   ImportNameTable: 0x2040
+# IMPORT-NEXT:   ModuleHandle: 0x3008
+# IMPORT-NEXT:   ImportAddressTable: 0x3010
+# IMPORT-NEXT:   ImportNameTable: 0x2044
 # IMPORT-NEXT:   BoundDelayImportTable: 0x0
 # IMPORT-NEXT:   UnloadDelayImportTable: 0x0
 # IMPORT-NEXT:   Import {
@@ -43,7 +44,7 @@
 # BASEREL-NEXT:   }
 # BASEREL-NEXT:   Entry {
 # BASEREL-NEXT:     Type: HIGHLOW
-# BASEREL-NEXT:     Address: 0x3008
+# BASEREL-NEXT:     Address: 0x3010
 # BASEREL-NEXT:   }
 # BASEREL-NEXT:   Entry {
 # BASEREL-NEXT:     Type: ABSOLUTE
@@ -52,20 +53,24 @@
 # BASEREL-NEXT: ]
 #
 # DISASM:    00401000 <.text>:
-# DISASM:      40100c:       f243 0c08       movw r12, #12296
+# DISASM:      40100c:       f243 0c10       movw r12, #12304
 # DISASM-NEXT:               f2c0 0c40       movt    r12, #64
 # DISASM-NEXT:               f000 b800       b.w     {{.+}} @ imm = #0
 # DISASM-NEXT:               e92d 480f       push.w  {r0, r1, r2, r3, r11, lr}
 # DISASM-NEXT:               f20d 0b10       addw    r11, sp, #16
 # DISASM-NEXT:               ed2d 0b10       vpush   {d0, d1, d2, d3, d4, d5, d6, d7}
 # DISASM-NEXT:               4661            mov     r1, r12
-# DISASM-NEXT:               f242 0000       movw r0, #8192
+# DISASM-NEXT:               f242 0004       movw r0, #8196
 # DISASM-NEXT:               f2c0 0040       movt    r0, #64
 # DISASM-NEXT:               f7ff ffe7       bl      0x401000 <.text>
 # DISASM-NEXT:               4684            mov     r12, r0
 # DISASM-NEXT:               ecbd 0b10       vpop    {d0, d1, d2, d3, d4, d5, d6, d7}
 # DISASM-NEXT:               e8bd 480f       pop.w   {r0, r1, r2, r3, r11, lr}
 # DISASM-NEXT:               4760            bx      r12
+#
+# DIR:         DelayImportDescriptorRVA: 0x2004
+# DIR-NEXT:    DelayImportDescriptorSize: 0x40
+
 
 --- !COFF
 header:
@@ -80,6 +85,14 @@ sections:
       - VirtualAddress:  0
         SymbolName:      __imp_function
         Type:            IMAGE_REL_ARM_MOV32T
+  - Name:            .rdata
+    Characteristics: [ IMAGE_SCN_CNT_INITIALIZED_DATA, IMAGE_SCN_MEM_READ ]
+    Alignment:       1
+    SectionData:     01
+  - Name:            .data
+    Characteristics: [ IMAGE_SCN_CNT_INITIALIZED_DATA, IMAGE_SCN_MEM_READ, IMAGE_SCN_MEM_WRITE ]
+    Alignment:       1
+    SectionData:     02
 symbols:
   - Name:            .text
     Value:           0

)

This makes a difference when linking executables with delay loaded
libraries for arm32; the delay loader implementation can load data from
the registry with instructions that assume alignment.

This issue does not show up when linking in MinGW mode, because a
PseudoRelocTableChunk gets injected, which also sets alignment, even if
the chunk itself is empty.

(cherry picked from commit c93c76b)
@tstellar tstellar merged commit 2fc8bea into llvm:release/18.x Mar 13, 2024
5 of 7 checks passed
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Projects
Development

Successfully merging this pull request may close these issues.

None yet

4 participants